Commit Graph

32833 Commits

Author SHA1 Message Date
Colin Ian King
aa96a93ba2 rcu: Fix spelling mistake "leval" -> "level"
This commit fixes a spelling mistake in a pr_info() message.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 16:00:20 -08:00
Paul E. McKenney
8c14263d35 rcu: React to callback overload by boosting RCU readers
RCU priority boosting currently is not applied until the grace period
is at least 250 milliseconds old (or the number of milliseconds specified
by the CONFIG_RCU_BOOST_DELAY Kconfig option).  Although this has worked
well, it can result in OOM under conditions of RCU callback flooding.
One can argue that the real-time systems using RCU priority boosting
should carefully avoid RCU callback flooding, but one can just as well
argue that an OOM is a rather obnoxious error message.

This commit therefore disables the RCU priority boosting delay when
there are excessive numbers of callbacks queued.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 16:00:20 -08:00
Paul E. McKenney
b2b00ddf19 rcu: React to callback overload by aggressively seeking quiescent states
In default configutions, RCU currently waits at least 100 milliseconds
before asking cond_resched() and/or resched_rcu() for help seeking
quiescent states to end a grace period.  But 100 milliseconds can be
one good long time during an RCU callback flood, for example, as can
happen when user processes repeatedly open and close files in a tight
loop.  These 100-millisecond gaps in successive grace periods during a
callback flood can result in excessive numbers of callbacks piling up,
unnecessarily increasing memory footprint.

This commit therefore asks cond_resched() and/or resched_rcu() for help
as early as the first FQS scan when at least one of the CPUs has more
than 20,000 callbacks queued, a number that can be changed using the new
rcutree.qovld kernel boot parameter.  An auxiliary qovld_calc variable
is used to avoid acquisition of locks that have not yet been initialized.
Early tests indicate that this reduces the RCU-callback memory footprint
during rcutorture floods by from 50% to 4x, depending on configuration.

Reported-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reported-by: Tejun Heo <tj@kernel.org>
[ paulmck: Fix bug located by Qian Cai. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Dexuan Cui <decui@microsoft.com>
Tested-by: Qian Cai <cai@lca.pw>
2020-02-20 16:00:20 -08:00
Paul E. McKenney
b5ea03709d rcu: Clear ->core_needs_qs at GP end or self-reported QS
The rcu_data structure's ->core_needs_qs field does not necessarily get
cleared in a timely fashion after the corresponding CPUs' quiescent state
has been reported.  From a functional viewpoint, no harm done, but this
can result in excessive invocation of RCU core processing, as witnessed
by the kernel test robot, which saw greatly increased softirq overhead.

This commit therefore restores the rcu_report_qs_rdp() function's
clearing of this field, but only when running on the corresponding CPU.
Cases where some other CPU reports the quiescent state (for example, on
behalf of an idle CPU) are handled by setting this field appropriately
within the __note_gp_changes() function's end-of-grace-period checks.
This handling is carried out regardless of whether the end of a grace
period actually happened, thus handling the case where a CPU goes non-idle
after a quiescent state is reported on its behalf, but before the grace
period ends.  This fix also avoids cross-CPU updates to ->core_needs_qs,

While in the area, this commit changes the __note_gp_changes() need_gp
variable's name to need_qs because it is a quiescent state that is needed
from the CPU in question.

Fixes: ed93dfc6bc ("rcu: Confine ->core_needs_qs accesses to the corresponding CPU")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 16:00:20 -08:00
Paul E. McKenney
28e09a2e48 locktorture: Forgive apparent unfairness if CPU hotplug
If CPU hotplug testing is enabled, a lock might appear to be maximally
unfair just because one of the CPUs was offline almost all the time.
This commit therefore forgives unfairness if CPU hotplug testing was
enabled.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:59:59 -08:00
Paul E. McKenney
c0e1472d80 locktorture: Use private random-number generators
Both lock_torture_writer() and lock_torture_reader() use the "static"
keyword on their DEFINE_TORTURE_RANDOM(rand) declarations, which means
that a single instance of a random-number generator are shared among all
the writers and another is shared among all the readers.  Unfortunately,
this random-number generator was not designed for concurrent access.
This commit therefore removes both "static" keywords so that each reader
and each writer gets its own random-number generator.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:59:59 -08:00
Paul E. McKenney
80c503e0e6 locktorture: Print ratio of acquisitions, not failures
The __torture_print_stats() function in locktorture.c carefully
initializes local variable "min" to statp[0].n_lock_acquired, but
then compares it to statp[i].n_lock_fail.  Given that the .n_lock_fail
field should normally be zero, and given the initialization, it seems
reasonable to display the maximum and minimum number acquisitions
instead of miscomputing the maximum and minimum number of failures.
This commit therefore switches from failures to acquisitions.

And this turns out to be not only a day-zero bug, but entirely my
own fault.  I hate it when that happens!

Fixes: 0af3fe1efa ("locktorture: Add a lock-torture kernel module")
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Peter Zijlstra <peterz@infradead.org>
2020-02-20 15:59:59 -08:00
Uladzislau Rezki (Sony)
613707929b rcu: Add a trace event for kfree_rcu() use of kfree_bulk()
The event is given three parameters, first one is the name
of RCU flavour, second one is the number of elements in array
for free and last one is an address of the array holding
pointers to be freed by the kfree_bulk() function.

To enable the trace event your kernel has to be build with
CONFIG_RCU_TRACE=y, after that it is possible to track the
events using ftrace subsystem.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:51 -08:00
Uladzislau Rezki (Sony)
34c8817455 rcu: Support kfree_bulk() interface in kfree_rcu()
The kfree_rcu() logic can be improved further by using kfree_bulk()
interface along with "basic batching support" introduced earlier.

The are at least two advantages of using "bulk" interface:
- in case of large number of kfree_rcu() requests kfree_bulk()
  reduces the per-object overhead caused by calling kfree()
  per-object.

- reduces the number of cache-misses due to "pointer chasing"
  between objects which can be far spread between each other.

This approach defines a new kfree_rcu_bulk_data structure that
stores pointers in an array with a specific size. Number of entries
in that array depends on PAGE_SIZE making kfree_rcu_bulk_data
structure to be exactly one page.

Since it deals with "block-chain" technique there is an extra
need in dynamic allocation when a new block is required. Memory
is allocated with GFP_NOWAIT | __GFP_NOWARN flags, i.e. that
allows to skip direct reclaim under low memory condition to
prevent stalling and fails silently under high memory pressure.

The "emergency path" gets maintained when a system is run out of
memory. In that case objects are linked into regular list.

The "rcuperf" was run to analyze this change in terms of memory
consumption and kfree_bulk() throughput.

1) Testing on the Intel(R) Xeon(R) W-2135 CPU @ 3.70GHz, 12xCPUs
with following parameters:

kfree_loops=200000 kfree_alloc_num=1000 kfree_rcu_test=1 kfree_vary_obj_size=1
dev.2020.01.10a branch

Default / CONFIG_SLAB
53607352517 ns, loops: 200000, batches: 1885, memory footprint: 1248MB
53529637912 ns, loops: 200000, batches: 1921, memory footprint: 1193MB
53570175705 ns, loops: 200000, batches: 1929, memory footprint: 1250MB

Patch / CONFIG_SLAB
23981587315 ns, loops: 200000, batches: 810, memory footprint: 1219MB
23879375281 ns, loops: 200000, batches: 822, memory footprint: 1190MB
24086841707 ns, loops: 200000, batches: 794, memory footprint: 1380MB

Default / CONFIG_SLUB
51291025022 ns, loops: 200000, batches: 1713, memory footprint: 741MB
51278911477 ns, loops: 200000, batches: 1671, memory footprint: 719MB
51256183045 ns, loops: 200000, batches: 1719, memory footprint: 647MB

Patch / CONFIG_SLUB
50709919132 ns, loops: 200000, batches: 1618, memory footprint: 456MB
50736297452 ns, loops: 200000, batches: 1633, memory footprint: 507MB
50660403893 ns, loops: 200000, batches: 1628, memory footprint: 429MB

in case of CONFIG_SLAB there is double increase in performance and
slightly higher memory usage. As for CONFIG_SLUB, the performance
figures are better together with lower memory usage.

2) Testing on the HiKey-960, arm64, 8xCPUs with below parameters:

CONFIG_SLAB=y
kfree_loops=200000 kfree_alloc_num=1000 kfree_rcu_test=1

102898760401 ns, loops: 200000, batches: 5822, memory footprint: 158MB
89947009882  ns, loops: 200000, batches: 6715, memory footprint: 115MB

rcuperf shows approximately ~12% better throughput in case of
using "bulk" interface. The "drain logic" or its RCU callback
does the work faster that leads to better throughput.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Tested-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:51 -08:00
Paul E. McKenney
3d05031ae6 rcu: Make nocb_gp_wait() double-check unexpected-callback warning
Currently, nocb_gp_wait() unconditionally complains if there is a
callback not already associated with a grace period.  This assumes that
either there was no such callback initially on the one hand, or that
the rcu_advance_cbs() function assigned all such callbacks to a grace
period on the other.  However, in theory there are some situations that
would prevent rcu_advance_cbs() from assigning all of the callbacks.

This commit therefore checks for unassociated callbacks immediately after
rcu_advance_cbs() returns, while the corresponding rcu_node structure's
->lock is still held.  If there are unassociated callbacks at that point,
the subsequent WARN_ON_ONCE() is disabled.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:23 -08:00
Paul E. McKenney
13817dd589 rcu: Tighten rcu_lockdep_assert_cblist_protected() check
The ->nocb_lock lockdep assertion is currently guarded by cpu_online(),
which is incorrect for no-CBs CPUs, whose callback lists must be
protected by ->nocb_lock regardless of whether or not the corresponding
CPU is online.  This situation could result in failure to detect bugs
resulting from failing to hold ->nocb_lock for offline CPUs.

This commit therefore removes the cpu_online() guard.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:23 -08:00
Paul E. McKenney
faa059c397 rcu: Optimize and protect atomic_cmpxchg() loop
This commit reworks the atomic_cmpxchg() loop in rcu_eqs_special_set()
to do only the initial read from the current CPU's rcu_data structure's
->dynticks field explicitly.  On subsequent passes, this value is instead
retained from the failing atomic_cmpxchg() operation.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:23 -08:00
Jules Irenge
92c0b889f2 rcu/nocb: Add missing annotation for rcu_nocb_bypass_unlock()
Sparse reports warning at rcu_nocb_bypass_unlock()

warning: context imbalance in rcu_nocb_bypass_unlock() - unexpected unlock

The root cause is a missing annotation of rcu_nocb_bypass_unlock()
which causes the warning.

This commit therefore adds the missing __releases(&rdp->nocb_bypass_lock)
annotation.

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
2020-02-20 15:58:23 -08:00
Jules Irenge
9ced454807 rcu: Add missing annotation for rcu_nocb_bypass_lock()
Sparse reports warning at rcu_nocb_bypass_lock()

|warning: context imbalance in rcu_nocb_bypass_lock() - wrong count at exit

To fix this, this commit adds an __acquires(&rdp->nocb_bypass_lock).
Given that rcu_nocb_bypass_lock() does actually call raw_spin_lock()
when raw_spin_trylock() fails, this not only fixes the warning but also
improves on the readability of the code.

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:23 -08:00
Paul E. McKenney
5648d65912 rcu: Don't flag non-starting GPs before GP kthread is running
Currently rcu_check_gp_start_stall() complains if a grace period takes
too long to start, where "too long" is roughly one RCU CPU stall-warning
interval.  This has worked well, but there are some debugging Kconfig
options (such as CONFIG_EFI_PGT_DUMP=y) that can make booting take a
very long time, so much so that the stall-warning interval has expired
before RCU's grace-period kthread has even been spawned.

This commit therefore resets the rcu_state.gp_req_activity and
rcu_state.gp_activity timestamps just before the grace-period kthread
is spawned, and modifies the checks and adds ordering to ensure that
if rcu_check_gp_start_stall() sees that the grace-period kthread
has been spawned, that it will also see the resets applied to the
rcu_state.gp_req_activity and rcu_state.gp_activity timestamps.

Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
[ paulmck: Fix whitespace issues reported by Qian Cai. ]
Tested-by: Qian Cai <cai@lca.pw>
[ paulmck: Simplify grace-period wakeup check per Steve Rostedt feedback. ]
2020-02-20 15:58:23 -08:00
Paul E. McKenney
aa24f93753 rcu: Fix rcu_barrier_callback() race condition
The rcu_barrier_callback() function does an atomic_dec_and_test(), and
if it is the last CPU to check in, does the required wakeup.  Either way,
it does an event trace.  Unfortunately, this is susceptible to the
following sequence of events:

o	CPU 0 invokes rcu_barrier_callback(), but atomic_dec_and_test()
	says that it is not last.  But at this point, CPU 0 is delayed,
	perhaps due to an NMI, SMI, or vCPU preemption.

o	CPU 1 invokes rcu_barrier_callback(), and atomic_dec_and_test()
	says that it is last.  So CPU 1 traces completion and does
	the needed wakeup.

o	The awakened rcu_barrier() function does cleanup and releases
	rcu_state.barrier_mutex.

o	Another CPU now acquires rcu_state.barrier_mutex and starts
	another round of rcu_barrier() processing, including updating
	rcu_state.barrier_sequence.

o	CPU 0 gets its act back together and does its tracing.  Except
	that rcu_state.barrier_sequence has already been updated, so
	its tracing is incorrect and probably quite confusing.
	(Wait!  Why did this CPU check in twice for one rcu_barrier()
	invocation???)

This commit therefore causes rcu_barrier_callback() to take a
snapshot of the value of rcu_state.barrier_sequence before invoking
atomic_dec_and_test(), thus guaranteeing that the event-trace output
is sensible, even if the timing of the event-trace output might still
be confusing.  (Wait!  Why did the old rcu_barrier() complete before
all of its CPUs checked in???)  But being that this is RCU, only so much
confusion can reasonably be eliminated.

This data race was reported by KCSAN.  Not appropriate for backporting
due to failure being unlikely and due to the mild consequences of the
failure, namely a confusing event trace.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:23 -08:00
Paul E. McKenney
59881bcd85 rcu: Add WRITE_ONCE() to rcu_state ->gp_start
The rcu_state structure's ->gp_start field is read locklessly, so this
commit adds the WRITE_ONCE() to an update in order to provide proper
documentation and READ_ONCE()/WRITE_ONCE() pairing.

This data race was reported by KCSAN.  Not appropriate for backporting
due to failure being unlikely.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:23 -08:00
Paul E. McKenney
57721fd15a rcu: Remove dead code from rcu_segcblist_insert_pend_cbs()
The rcu_segcblist_insert_pend_cbs() function currently (partially)
initializes the rcu_cblist that it pulls callbacks from.  However, all
the resulting stores are dead because all callers pass in the address of
an on-stack cblist that is not used afterwards.  This commit therefore
removes this pointless initialization.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:23 -08:00
Eric Dumazet
90c018942c timer: Use hlist_unhashed_lockless() in timer_pending()
The timer_pending() function is mostly used in lockless contexts, so
Without proper annotations, KCSAN might detect a data-race [1].

Using hlist_unhashed_lockless() instead of hand-coding it seems
appropriate (as suggested by Paul E. McKenney).

[1]

BUG: KCSAN: data-race in del_timer / detach_if_pending

write to 0xffff88808697d870 of 8 bytes by task 10 on cpu 0:
 __hlist_del include/linux/list.h:764 [inline]
 detach_timer kernel/time/timer.c:815 [inline]
 detach_if_pending+0xcd/0x2d0 kernel/time/timer.c:832
 try_to_del_timer_sync+0x60/0xb0 kernel/time/timer.c:1226
 del_timer_sync+0x6b/0xa0 kernel/time/timer.c:1365
 schedule_timeout+0x2d2/0x6e0 kernel/time/timer.c:1896
 rcu_gp_fqs_loop+0x37c/0x580 kernel/rcu/tree.c:1639
 rcu_gp_kthread+0x143/0x230 kernel/rcu/tree.c:1799
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffff88808697d870 of 8 bytes by task 12060 on cpu 1:
 del_timer+0x3b/0xb0 kernel/time/timer.c:1198
 sk_stop_timer+0x25/0x60 net/core/sock.c:2845
 inet_csk_clear_xmit_timers+0x69/0xa0 net/ipv4/inet_connection_sock.c:523
 tcp_clear_xmit_timers include/net/tcp.h:606 [inline]
 tcp_v4_destroy_sock+0xa3/0x3f0 net/ipv4/tcp_ipv4.c:2096
 inet_csk_destroy_sock+0xf4/0x250 net/ipv4/inet_connection_sock.c:836
 tcp_close+0x6f3/0x970 net/ipv4/tcp.c:2497
 inet_release+0x86/0x100 net/ipv4/af_inet.c:427
 __sock_release+0x85/0x160 net/socket.c:590
 sock_close+0x24/0x30 net/socket.c:1268
 __fput+0x1e1/0x520 fs/file_table.c:280
 ____fput+0x1f/0x30 fs/file_table.c:313
 task_work_run+0xf6/0x130 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2b4/0x2c0 arch/x86/entry/common.c:163

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12060 Comm: syz-executor.5 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine,

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
[ paulmck: Pulled in Eric's later amendments. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:22 -08:00
Paul E. McKenney
3ca3b0e2cb rcu: Add *_ONCE() to rcu_node ->boost_kthread_status
The rcu_node structure's ->boost_kthread_status field is accessed
locklessly, so this commit causes all updates to use WRITE_ONCE() and
all reads to use READ_ONCE().

This data race was reported by KCSAN.  Not appropriate for backporting
due to failure being unlikely.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:22 -08:00
Paul E. McKenney
2a2ae872ef rcu: Add *_ONCE() to rcu_data ->rcu_forced_tick
The rcu_data structure's ->rcu_forced_tick field is read locklessly, so
this commit adds WRITE_ONCE() to all updates and READ_ONCE() to all
lockless reads.

This data race was reported by KCSAN.  Not appropriate for backporting
due to failure being unlikely.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:22 -08:00
Paul E. McKenney
a5b8950180 rcu: Add READ_ONCE() to rcu_data ->gpwrap
The rcu_data structure's ->gpwrap field is read locklessly, and so
this commit adds the required READ_ONCE() to a pair of laods in order
to avoid destructive compiler optimizations.

This data race was reported by KCSAN.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:22 -08:00
SeongJae Park
65bb0dc437 rcu: Fix typos in file-header comments
Convert to plural and add a note that this is for Tree RCU.

Signed-off-by: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:22 -08:00
Paul E. McKenney
8ff37290d6 rcu: Add *_ONCE() for grace-period progress indicators
The various RCU structures' ->gp_seq, ->gp_seq_needed, ->gp_req_activity,
and ->gp_activity fields are read locklessly, so they must be updated with
WRITE_ONCE() and, when read locklessly, with READ_ONCE().  This commit makes
these changes.

This data race was reported by KCSAN.  Not appropriate for backporting
due to failure being unlikely.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:22 -08:00
Paul E. McKenney
bfeebe2421 rcu: Add READ_ONCE() to rcu_segcblist ->tails[]
The rcu_segcblist structure's ->tails[] array entries are read
locklessly, so this commit adds the READ_ONCE() to a load in order to
avoid destructive compiler optimizations.

This data race was reported by KCSAN.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:22 -08:00
Paul E. McKenney
0050c7b2d2 locking/rtmutex: rcu: Add WRITE_ONCE() to rt_mutex ->owner
The rt_mutex structure's ->owner field is read locklessly, so this
commit adds the WRITE_ONCE() to an update in order to provide proper
documentation and READ_ONCE()/WRITE_ONCE() pairing.

This data race was reported by KCSAN.  Not appropriate for backporting
due to failure being unlikely.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
2020-02-20 15:58:22 -08:00
Paul E. McKenney
105abf82b0 rcu: Add WRITE_ONCE() to rcu_node ->qsmaskinitnext
The rcu_state structure's ->qsmaskinitnext field is read locklessly,
so this commit adds the WRITE_ONCE() to an update in order to provide
proper documentation and READ_ONCE()/WRITE_ONCE() pairing.

This data race was reported by KCSAN.  Not appropriate for backporting
due to failure being unlikely for systems not doing incessant CPU-hotplug
operations.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:22 -08:00
Paul E. McKenney
2906d2154c rcu: Add WRITE_ONCE() to rcu_state ->gp_req_activity
The rcu_state structure's ->gp_req_activity field is read locklessly,
so this commit adds the WRITE_ONCE() to an update in order to provide
proper documentation and READ_ONCE()/WRITE_ONCE() pairing.

This data race was reported by KCSAN.  Not appropriate for backporting
due to failure being unlikely.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:22 -08:00
Paul E. McKenney
0937d04573 rcu: Add READ_ONCE() to rcu_node ->gp_seq
The rcu_node structure's ->gp_seq field is read locklessly, so this
commit adds the READ_ONCE() to several loads in order to avoid
destructive compiler optimizations.

This data race was reported by KCSAN.  Not appropriate for backporting
because this affects only tracing and warnings.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:22 -08:00
Paul E. McKenney
b0c18c8773 rcu: Add WRITE_ONCE to rcu_node ->exp_seq_rq store
The rcu_node structure's ->exp_seq_rq field is read locklessly, so
this commit adds the WRITE_ONCE() to a load in order to provide proper
documentation and READ_ONCE()/WRITE_ONCE() pairing.

This data race was reported by KCSAN.  Not appropriate for backporting
due to failure being unlikely.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:22 -08:00
Paul E. McKenney
7672d647dd rcu: Add WRITE_ONCE() to rcu_node ->qsmask update
The rcu_node structure's ->qsmask field is read locklessly, so this
commit adds the WRITE_ONCE() to an update in order to provide proper
documentation and READ_ONCE()/WRITE_ONCE() pairing.

This data race was reported by KCSAN.  Not appropriate for backporting
due to failure being unlikely.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:22 -08:00
Paul E. McKenney
8a7e8f5171 rcu: Provide debug symbols and line numbers in KCSAN runs
This commit adds "-g -fno-omit-frame-pointer" to ease interpretation
of KCSAN output, but only for CONFIG_KCSAN=y kerrnels.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:21 -08:00
Paul E. McKenney
24bb9eccf7 rcu: Fix exp_funnel_lock()/rcu_exp_wait_wake() datarace
The rcu_node structure's ->exp_seq_rq field is accessed locklessly, so
updates must use WRITE_ONCE().  This commit therefore adds the needed
WRITE_ONCE() invocation where it was missed.

This data race was reported by KCSAN.  Not appropriate for backporting
due to failure being unlikely.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:21 -08:00
Paul E. McKenney
82dd8419e2 rcu: Warn on for_each_leaf_node_cpu_mask() from non-leaf
The for_each_leaf_node_cpu_mask() and for_each_leaf_node_possible_cpu()
macros must be invoked only on leaf rcu_node structures.  Failing to
abide by this restriction can result in infinite loops on systems with
more than 64 CPUs (or for more than 32 CPUs on 32-bit systems).  This
commit therefore adds WARN_ON_ONCE() calls to make misuse of these two
macros easier to debug.

Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-02-20 15:58:21 -08:00
Masami Hiramatsu
d8a953ddde bootconfig: Set CONFIG_BOOT_CONFIG=n by default
Set CONFIG_BOOT_CONFIG=n by default. This also warns
user if CONFIG_BOOT_CONFIG=n but "bootconfig" is given
in the kernel command line.

Link: http://lkml.kernel.org/r/158220111291.26565.9036889083940367969.stgit@devnote2

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-20 17:52:12 -05:00
Masami Hiramatsu
7ab215f22d tracing: Clear trace_state when starting trace
Clear trace_state data structure when starting trace
in __synth_event_trace_start() internal function.

Currently trace_state is initialized only in the
synth_event_trace_start() API, but the trace_state
in synth_event_trace() and synth_event_trace_array()
are on the stack without initialization.
This means those APIs will see wrong parameters and
wil skip closing process in __synth_event_trace_end()
because trace_state->disabled may be !0.

Link: http://lkml.kernel.org/r/158193315899.8868.1781259176894639952.stgit@devnote2

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-20 17:48:59 -05:00
Steven Rostedt (VMware)
78041c0c9e tracing: Disable trace_printk() on post poned tests
The tracing seftests checks various aspects of the tracing infrastructure,
and one is filtering. If trace_printk() is active during a self test, it can
cause the filtering to fail, which will disable that part of the trace.

To keep the selftests from failing because of trace_printk() calls,
trace_printk() checks the variable tracing_selftest_running, and if set, it
does not write to the tracing buffer.

As some tracers were registered earlier in boot, the selftest they triggered
would fail because not all the infrastructure was set up for the full
selftest. Thus, some of the tests were post poned to when their
infrastructure was ready (namely file system code). The postpone code did
not set the tracing_seftest_running variable, and could fail if a
trace_printk() was added and executed during their run.

Cc: stable@vger.kernel.org
Fixes: 9afecfbb95 ("tracing: Postpone tracer start-up tests till the system is more robust")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-20 17:43:58 -05:00
Steven Rostedt (VMware)
3c18a9be7c tracing: Have synthetic event test use raw_smp_processor_id()
The test code that tests synthetic event creation pushes in as one of its
test fields the current CPU using "smp_processor_id()". As this is just
something to see if the value is correctly passed in, and the actual CPU
used does not matter, use raw_smp_processor_id(), otherwise with debug
preemption enabled, a warning happens as the smp_processor_id() is called
without preemption enabled.

Link: http://lkml.kernel.org/r/20200220162950.35162579@gandalf.local.home

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-20 17:43:41 -05:00
Tom Zanussi
784bd0847e tracing: Fix number printing bug in print_synth_event()
Fix a varargs-related bug in print_synth_event() which resulted in
strange output and oopses on 32-bit x86 systems. The problem is that
trace_seq_printf() expects the varargs to match the format string, but
print_synth_event() was always passing u64 values regardless.  This
results in unspecified behavior when unpacking with va_arg() in
trace_seq_printf().

Add a function that takes the size into account when calling
trace_seq_printf().

Before:

  modprobe-1731  [003] ....   919.039758: gen_synth_test: next_pid_field=777(null)next_comm_field=hula hoops ts_ns=1000000 ts_ms=1000 cpu=3(null)my_string_field=thneed my_int_field=598(null)

After:

 insmod-1136  [001] ....    36.634590: gen_synth_test: next_pid_field=777 next_comm_field=hula hoops ts_ns=1000000 ts_ms=1000 cpu=1 my_string_field=thneed my_int_field=598

Link: http://lkml.kernel.org/r/a9b59eb515dbbd7d4abe53b347dccf7a8e285657.1581720155.git.zanussi@kernel.org

Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-20 16:24:17 -05:00
Tom Zanussi
3843083772 tracing: Check that number of vals matches number of synth event fields
Commit 7276531d4036('tracing: Consolidate trace() functions')
inadvertently dropped the synth_event_trace() and
synth_event_trace_array() checks that verify the number of values
passed in matches the number of fields in the synthetic event being
traced, so add them back.

Link: http://lkml.kernel.org/r/32819cac708714693669e0dfe10fe9d935e94a16.1581720155.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-20 16:24:17 -05:00
Tom Zanussi
1d9d4c9019 tracing: Make synth_event trace functions endian-correct
synth_event_trace(), synth_event_trace_array() and
__synth_event_add_val() write directly into the trace buffer and need
to take endianness into account, like trace_event_raw_event_synth()
does.

Link: http://lkml.kernel.org/r/2011354355e405af9c9d28abba430d1f5ff7771a.1581720155.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-20 16:24:17 -05:00
Tom Zanussi
279eef0531 tracing: Make sure synth_event_trace() example always uses u64
synth_event_trace() is the varargs version of synth_event_trace_array(),
which takes an array of u64, as do synth_event_add_val() et al.

To not only be consistent with those, but also to address the fact
that synth_event_trace() expects every arg to be of the same type
since it doesn't also pass in e.g. a format string, the caller needs
to make sure all args are of the same type, u64.  u64 is used because
it needs to accomodate the largest type available in synthetic events,
which is u64.

This fixes the bug reported by the kernel test robot/Rong Chen.

Link: https://lore.kernel.org/lkml/20200212113444.GS12867@shao2-debian/
Link: http://lkml.kernel.org/r/894c4e955558b521210ee0642ba194a9e603354c.1581720155.git.zanussi@kernel.org

Fixes: 9fe41efaca ("tracing: Add synth event generation test module")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-20 16:24:17 -05:00
Morten Rasmussen
000619680c sched/fair: Remove wake_cap()
Capacity-awareness in the wake-up path previously involved disabling
wake_affine in certain scenarios. We have just made select_idle_sibling()
capacity-aware, so this isn't needed anymore.

Remove wake_cap() entirely.

Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
[Changelog tweaks]
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[Changelog tweaks]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200206191957.12325-5-valentin.schneider@arm.com
2020-02-20 21:03:15 +01:00
Valentin Schneider
f8459197e7 sched/core: Remove for_each_lower_domain()
The last remaining user of this macro has just been removed, get rid of it.

Suggested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lkml.kernel.org/r/20200206191957.12325-4-valentin.schneider@arm.com
2020-02-20 21:03:15 +01:00
Morten Rasmussen
a526d46679 sched/topology: Remove SD_BALANCE_WAKE on asymmetric capacity systems
SD_BALANCE_WAKE was previously added to lower sched_domain levels on
asymmetric CPU capacity systems by commit:

  9ee1cda5ee ("sched/core: Enable SD_BALANCE_WAKE for asymmetric capacity systems")

to enable the use of find_idlest_cpu() and friends to find an appropriate
CPU for tasks.

That responsibility has now been shifted to select_idle_sibling() and
friends, and hence the flag can be removed. Note that this causes
asymmetric CPU capacity systems to no longer enter the slow wakeup path
(find_idlest_cpu()) on wakeups - only on execs and forks (which is aligned
with all other mainline topologies).

Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
[Changelog tweaks]
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lkml.kernel.org/r/20200206191957.12325-3-valentin.schneider@arm.com
2020-02-20 21:03:14 +01:00
Morten Rasmussen
b7a331615d sched/fair: Add asymmetric CPU capacity wakeup scan
Issue
=====

On asymmetric CPU capacity topologies, we currently rely on wake_cap() to
drive select_task_rq_fair() towards either:

- its slow-path (find_idlest_cpu()) if either the previous or
  current (waking) CPU has too little capacity for the waking task
- its fast-path (select_idle_sibling()) otherwise

Commit:

  3273163c67 ("sched/fair: Let asymmetric CPU configurations balance at wake-up")

points out that this relies on the assumption that "[...]the CPU capacities
within an SD_SHARE_PKG_RESOURCES domain (sd_llc) are homogeneous".

This assumption no longer holds on newer generations of big.LITTLE
systems (DynamIQ), which can accommodate CPUs of different compute capacity
within a single LLC domain. To hopefully paint a better picture, a regular
big.LITTLE topology would look like this:

  +---------+ +---------+
  |   L2    | |   L2    |
  +----+----+ +----+----+
  |CPU0|CPU1| |CPU2|CPU3|
  +----+----+ +----+----+
      ^^^         ^^^
    LITTLEs      bigs

which would result in the following scheduler topology:

  DIE [         ] <- sd_asym_cpucapacity
  MC  [   ] [   ] <- sd_llc
       0 1   2 3

Conversely, a DynamIQ topology could look like:

  +-------------------+
  |        L3         |
  +----+----+----+----+
  | L2 | L2 | L2 | L2 |
  +----+----+----+----+
  |CPU0|CPU1|CPU2|CPU3|
  +----+----+----+----+
     ^^^^^     ^^^^^
    LITTLEs    bigs

which would result in the following scheduler topology:

  MC [       ] <- sd_llc, sd_asym_cpucapacity
      0 1 2 3

What this means is that, on DynamIQ systems, we could pass the wake_cap()
test (IOW presume the waking task fits on the CPU capacities of some LLC
domain), thus go through select_idle_sibling().
This function operates on an LLC domain, which here spans both bigs and
LITTLEs, so it could very well pick a CPU of too small capacity for the
task, despite there being fitting idle CPUs - it very much depends on the
CPU iteration order, on which we have absolutely no guarantees
capacity-wise.

Implementation
==============

Introduce yet another select_idle_sibling() helper function that takes CPU
capacity into account. The policy is to pick the first idle CPU which is
big enough for the task (task_util * margin < cpu_capacity). If no
idle CPU is big enough, we pick the idle one with the highest capacity.

Unlike other select_idle_sibling() helpers, this one operates on the
sd_asym_cpucapacity sched_domain pointer, which is guaranteed to span all
known CPU capacities in the system. As such, this will work for both
"legacy" big.LITTLE (LITTLEs & bigs split at MC, joined at DIE) and for
newer DynamIQ systems (e.g. LITTLEs and bigs in the same MC domain).

Note that this limits the scope of select_idle_sibling() to
select_idle_capacity() for asymmetric CPU capacity systems - the LLC domain
will not be scanned, and no further heuristic will be applied.

Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://lkml.kernel.org/r/20200206191957.12325-2-valentin.schneider@arm.com
2020-02-20 21:03:14 +01:00
Scott Wood
82e0516ce3 sched/core: Remove duplicate assignment in sched_tick_remote()
A redundant "curr = rq->curr" was added; remove it.

Fixes: ebc0f83c78 ("timers/nohz: Update NOHZ load in remote tick")
Signed-off-by: Scott Wood <swood@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1580776558-12882-1-git-send-email-swood@redhat.com
2020-02-20 21:03:13 +01:00
Alexandre Belloni
b0c609ab20 PM / hibernate: fix typo "reserverd_size" -> "reserved_size"
Fix a mistake in a variable name in a comment.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-02-20 11:58:01 +01:00
David S. Miller
41f57cfde1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
pull-request: bpf 2020-02-19

The following pull-request contains BPF updates for your *net* tree.

We've added 10 non-merge commits during the last 10 day(s) which contain
a total of 10 files changed, 93 insertions(+), 31 deletions(-).

The main changes are:

1) batched bpf hashtab fixes from Brian and Yonghong.

2) various selftests and libbpf fixes.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-19 16:42:35 -08:00
Yonghong Song
b9aff38de2 bpf: Fix a potential deadlock with bpf_map_do_batch
Commit 057996380a ("bpf: Add batch ops to all htab bpf map")
added lookup_and_delete batch operation for hash table.
The current implementation has bpf_lru_push_free() inside
the bucket lock, which may cause a deadlock.

syzbot reports:
   -> #2 (&htab->buckets[i].lock#2){....}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:159
       htab_lru_map_delete_node+0xce/0x2f0 kernel/bpf/hashtab.c:593
       __bpf_lru_list_shrink_inactive kernel/bpf/bpf_lru_list.c:220 [inline]
       __bpf_lru_list_shrink+0xf9/0x470 kernel/bpf/bpf_lru_list.c:266
       bpf_lru_list_pop_free_to_local kernel/bpf/bpf_lru_list.c:340 [inline]
       bpf_common_lru_pop_free kernel/bpf/bpf_lru_list.c:447 [inline]
       bpf_lru_pop_free+0x87c/0x1670 kernel/bpf/bpf_lru_list.c:499
       prealloc_lru_pop+0x2c/0xa0 kernel/bpf/hashtab.c:132
       __htab_lru_percpu_map_update_elem+0x67e/0xa90 kernel/bpf/hashtab.c:1069
       bpf_percpu_hash_update+0x16e/0x210 kernel/bpf/hashtab.c:1585
       bpf_map_update_value.isra.0+0x2d7/0x8e0 kernel/bpf/syscall.c:181
       generic_map_update_batch+0x41f/0x610 kernel/bpf/syscall.c:1319
       bpf_map_do_batch+0x3f5/0x510 kernel/bpf/syscall.c:3348
       __do_sys_bpf+0x9b7/0x41e0 kernel/bpf/syscall.c:3460
       __se_sys_bpf kernel/bpf/syscall.c:3355 [inline]
       __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:3355
       do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

   -> #0 (&loc_l->lock){....}:
       check_prev_add kernel/locking/lockdep.c:2475 [inline]
       check_prevs_add kernel/locking/lockdep.c:2580 [inline]
       validate_chain kernel/locking/lockdep.c:2970 [inline]
       __lock_acquire+0x2596/0x4a00 kernel/locking/lockdep.c:3954
       lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4484
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:159
       bpf_common_lru_push_free kernel/bpf/bpf_lru_list.c:516 [inline]
       bpf_lru_push_free+0x250/0x5b0 kernel/bpf/bpf_lru_list.c:555
       __htab_map_lookup_and_delete_batch+0x8d4/0x1540 kernel/bpf/hashtab.c:1374
       htab_lru_map_lookup_and_delete_batch+0x34/0x40 kernel/bpf/hashtab.c:1491
       bpf_map_do_batch+0x3f5/0x510 kernel/bpf/syscall.c:3348
       __do_sys_bpf+0x1f7d/0x41e0 kernel/bpf/syscall.c:3456
       __se_sys_bpf kernel/bpf/syscall.c:3355 [inline]
       __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:3355
       do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

    Possible unsafe locking scenario:

          CPU0                    CPU2
          ----                    ----
     lock(&htab->buckets[i].lock#2);
                                  lock(&l->lock);
                                  lock(&htab->buckets[i].lock#2);
     lock(&loc_l->lock);

    *** DEADLOCK ***

To fix the issue, for htab_lru_map_lookup_and_delete_batch() in CPU0,
let us do bpf_lru_push_free() out of the htab bucket lock. This can
avoid the above deadlock scenario.

Fixes: 057996380a ("bpf: Add batch ops to all htab bpf map")
Reported-by: syzbot+a38ff3d9356388f2fb83@syzkaller.appspotmail.com
Reported-by: syzbot+122b5421d14e68f29cd1@syzkaller.appspotmail.com
Suggested-by: Hillf Danton <hdanton@sina.com>
Suggested-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Brian Vazquez <brianvv@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200219234757.3544014-1-yhs@fb.com
2020-02-19 16:01:25 -08:00
Brian Vazquez
492e0d0d6f bpf: Do not grab the bucket spinlock by default on htab batch ops
Grabbing the spinlock for every bucket even if it's empty, was causing
significant perfomance cost when traversing htab maps that have only a
few entries. This patch addresses the issue by checking first the
bucket_cnt, if the bucket has some entries then we go and grab the
spinlock and proceed with the batching.

Tested with a htab of size 50K and different value of populated entries.

Before:
  Benchmark             Time(ns)        CPU(ns)
  ---------------------------------------------
  BM_DumpHashMap/1       2759655        2752033
  BM_DumpHashMap/10      2933722        2930825
  BM_DumpHashMap/200     3171680        3170265
  BM_DumpHashMap/500     3639607        3635511
  BM_DumpHashMap/1000    4369008        4364981
  BM_DumpHashMap/5k     11171919       11134028
  BM_DumpHashMap/20k    69150080       69033496
  BM_DumpHashMap/39k   190501036      190226162

After:
  Benchmark             Time(ns)        CPU(ns)
  ---------------------------------------------
  BM_DumpHashMap/1        202707         200109
  BM_DumpHashMap/10       213441         210569
  BM_DumpHashMap/200      478641         472350
  BM_DumpHashMap/500      980061         967102
  BM_DumpHashMap/1000    1863835        1839575
  BM_DumpHashMap/5k      8961836        8902540
  BM_DumpHashMap/20k    69761497       69322756
  BM_DumpHashMap/39k   187437830      186551111

Fixes: 057996380a ("bpf: Add batch ops to all htab bpf map")
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200218172552.215077-1-brianvv@google.com
2020-02-19 15:59:30 -08:00
Daniel Xu
fff7b64355 bpf: Add bpf_read_branch_records() helper
Branch records are a CPU feature that can be configured to record
certain branches that are taken during code execution. This data is
particularly interesting for profile guided optimizations. perf has had
branch record support for a while but the data collection can be a bit
coarse grained.

We (Facebook) have seen in experiments that associating metadata with
branch records can improve results (after postprocessing). We generally
use bpf_probe_read_*() to get metadata out of userspace. That's why bpf
support for branch records is useful.

Aside from this particular use case, having branch data available to bpf
progs can be useful to get stack traces out of userspace applications
that omit frame pointers.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200218030432.4600-2-dxu@dxuuu.xyz
2020-02-19 14:37:36 -08:00
Stephen Kitt
140588bfed s390: remove obsolete ieee_emulation_warnings
s390 math emulation was removed with commit 5a79859ae0 ("s390:
remove 31 bit support"), rendering ieee_emulation_warnings useless.
The code still built because it was protected by CONFIG_MATHEMU, which
was no longer selectable.

This patch removes the sysctl_ieee_emulation_warnings declaration and
the sysctl entry declaration.

Link: https://lkml.kernel.org/r/20200214172628.3598516-1-steve@sk2.org
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Stephen Kitt <steve@sk2.org>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-02-19 13:51:46 +01:00
Linus Torvalds
0a44cac810 dma-mapping fixes for 5.6
- give command line cma= precedence over the CONFIG_ option
    (Nicolas Saenz Julienne)
  - always allow 32-bit DMA, even for weirdly placed ZONE_DMA
  - improve the debug printks when memory is not addressable, to help
    find problems with swiotlb initialization
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Merge tag 'dma-mapping-5.6' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - give command line cma= precedence over the CONFIG_ option (Nicolas
   Saenz Julienne)

 - always allow 32-bit DMA, even for weirdly placed ZONE_DMA

 - improve the debug printks when memory is not addressable, to help
   find problems with swiotlb initialization

* tag 'dma-mapping-5.6' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: improve DMA mask overflow reporting
  dma-direct: improve swiotlb error reporting
  dma-direct: relax addressability checks in dma_direct_supported
  dma-contiguous: CMA: give precedence to cmdline
2020-02-18 15:06:38 -08:00
Song Liu
b80b033bed bpf: Allow bpf_perf_event_read_value in all BPF programs
bpf_perf_event_read_value() is NMI safe. Enable it for all BPF programs.
This can be used in fentry/fexit to profile BPF program and individual
kernel function with hardware counters.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200214234146.2910011-1-songliubraving@fb.com
2020-02-18 16:08:27 +01:00
Gustavo A. R. Silva
0f74226649 kernel: module: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-02-17 21:40:55 +01:00
Amol Grover
5fb1c2a5bb posix-timers: Pass lockdep expression to RCU lists
head is traversed using hlist_for_each_entry_rcu outside an RCU read-side
critical section but under the protection of hash_lock.

Hence, add corresponding lockdep expression to silence false-positive
lockdep warnings, and harden RCU lists.

[ tglx: Removed the macro and put the condition right where it's used ]

Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200216074330.GA14025@workstation-portable
2020-02-17 20:12:19 +01:00
Alexander Popov
6e317c32fd timer: Improve the comment describing schedule_timeout()
When working commit 6dcd5d7a7a, a mistake was noticed by Linus:
schedule_timeout() was called without setting the task state to anything
particular.

It calls the scheduler, but doesn't delay anything, because the task stays
runnable. That happens because sched_submit_work() does nothing for tasks
in TASK_RUNNING state.

That turned out to be the intended behavior. Adding a WARN() is not useful
as the task could be woken up right after setting the state and before
reaching schedule_timeout().

Improve the comment about schedule_timeout() and describe that more
explicitly.

Signed-off-by: Alexander Popov <alex.popov@linux.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200117225900.16340-1-alex.popov@linux.com
2020-02-17 20:12:19 +01:00
Thomas Gleixner
2d6b01bd88 lib/vdso: Move VCLOCK_TIMENS to vdso_clock_modes
Move the time namespace indicator clock mode to the other ones for
consistency sake.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.656097274@linutronix.de
2020-02-17 20:12:17 +01:00
Thomas Gleixner
c7a18100bd lib/vdso: Avoid highres update if clocksource is not VDSO capable
If the current clocksource is not VDSO capable there is no point in
updating the high resolution parts of the VDSO data.

Replace the architecture specific check with a check for a VDSO capable
clocksource and skip the update if there is none.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.563379423@linutronix.de
2020-02-17 20:12:17 +01:00
Thomas Gleixner
f86fd32db7 lib/vdso: Cleanup clock mode storage leftovers
Now that all architectures are converted to use the generic storage the
helpers and conditionals can be removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.470699892@linutronix.de
2020-02-17 20:12:17 +01:00
Johannes Krude
e20d3a055a bpf, offload: Replace bitwise AND by logical AND in bpf_prog_offload_info_fill
This if guards whether user-space wants a copy of the offload-jited
bytecode and whether this bytecode exists. By erroneously doing a bitwise
AND instead of a logical AND on user- and kernel-space buffer-size can lead
to no data being copied to user-space especially when user-space size is a
power of two and bigger then the kernel-space buffer.

Fixes: fcfb126def ("bpf: add new jited info fields in bpf_dev_offload and bpf_prog_info")
Signed-off-by: Johannes Krude <johannes@krude.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/bpf/20200212193227.GA3769@phlox.h.transitiv.net
2020-02-17 16:53:49 +01:00
Thomas Gleixner
5d51bee725 clocksource: Add common vdso clock mode storage
All architectures which use the generic VDSO code have their own storage
for the VDSO clock mode. That's pointless and just requires duplicate code.

Provide generic storage for it. The new Kconfig symbol is intermediate and
will be removed once all architectures are converted over.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.028046322@linutronix.de
2020-02-17 14:40:23 +01:00
Linus Torvalds
ef78e5b7de Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Misc fixes all over the place:

   - Fix NUMA over-balancing between lightly loaded nodes. This is
     fallout of the big load-balancer rewrite.

   - Fix the NOHZ remote loadavg update logic, which fixes anomalies
     like reported 150 loadavg on mostly idle CPUs.

   - Fix XFS performance/scalability

   - Fix throttled groups unbound task-execution bug

   - Fix PSI procfs boundary condition

   - Fix the cpu.uclamp.{min,max} cgroup configuration write checks

   - Fix DocBook annotations

   - Fix RCU annotations

   - Fix overly CPU-intensive housekeeper CPU logic loop on large CPU
     counts"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix kernel-doc warning in attach_entity_load_avg()
  sched/core: Annotate curr pointer in rq with __rcu
  sched/psi: Fix OOB write when writing 0 bytes to PSI files
  sched/fair: Allow a per-CPU kthread waking a task to stack on the same CPU, to fix XFS performance regression
  sched/fair: Prevent unlimited runtime on throttled group
  sched/nohz: Optimize get_nohz_timer_target()
  sched/uclamp: Reject negative values in cpu_uclamp_write()
  sched/fair: Allow a small load imbalance between low utilisation SD_NUMA domains
  timers/nohz: Update NOHZ load in remote tick
  sched/core: Don't skip remote tick for idle CPUs
2020-02-15 12:51:22 -08:00
Linus Torvalds
4e03e4e6d2 Power management fixes for 5.6-rc2
Fix three issues related to the handling of wakeup events signaled
 through the ACPI SCI while suspended to idle (Rafael Wysocki) and
 unexport an internal cpufreq variable (Yangtao Li).
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Merge tag 'pm-5.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "Fix three issues related to the handling of wakeup events signaled
  through the ACPI SCI while suspended to idle (Rafael Wysocki) and
  unexport an internal cpufreq variable (Yangtao Li)"

* tag 'pm-5.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: PM: s2idle: Prevent spurious SCIs from waking up the system
  ACPICA: Introduce acpi_any_gpe_status_set()
  ACPI: PM: s2idle: Avoid possible race related to the EC GPE
  ACPI: EC: Fix flushing of pending work
  cpufreq: Make cpufreq_global_kobject static
2020-02-14 12:34:30 -08:00
Frederic Weisbecker
490f561b78 context-tracking: Introduce CONFIG_HAVE_TIF_NOHZ
A few archs (x86, arm, arm64) don't rely anymore on TIF_NOHZ to call
into context tracking on user entry/exit but instead use static keys
(or not) to optimize those calls. Ideally every arch should migrate to
that behaviour in the long run.

Settle a config option to let those archs remove their TIF_NOHZ
definitions.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: David S. Miller <davem@davemloft.net>
2020-02-14 16:05:04 +01:00
Rafael J. Wysocki
814d51f888 PM: QoS: Make CPU latency QoS depend on CONFIG_CPU_IDLE
Because cpuidle is the only user of the effective constraint coming
from the CPU latency QoS, add #ifdef CONFIG_CPU_IDLE around that code
to avoid building it unnecessarily.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-14 10:37:27 +01:00
Rafael J. Wysocki
fe52de36dc PM: QoS: Update file information comments
Update the file information comments in include/linux/pm_qos.h
and kernel/power/qos.c by adding titles along with copyright and
authors information to them and changing the qos.c description to
better reflect its contents (outdated information is dropped from
it in particular).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-14 10:37:26 +01:00
Rafael J. Wysocki
67b06ba018 PM: QoS: Drop PM_QOS_CPU_DMA_LATENCY and rename related functions
Drop the PM QoS classes enum including PM_QOS_CPU_DMA_LATENCY,
drop the wrappers around pm_qos_request(), pm_qos_request_active(),
and pm_qos_add/update/remove_request() introduced previously, rename
these functions, respectively, to cpu_latency_qos_limit(),
cpu_latency_qos_request_active(), and
cpu_latency_qos_add/update/remove_request(), and update their
kerneldoc comments.  [While at it, drop some useless comments from
these functions.]

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-14 10:37:26 +01:00
Thomas Gleixner
cba6437a18 genirq/proc: Reject invalid affinity masks (again)
Qian Cai reported that the WARN_ON() in the x86/msi affinity setting code,
which catches cases where the affinity setting is not done on the CPU which
is the current target of the interrupt, triggers during CPU hotplug stress
testing.

It turns out that the warning which was added with the commit addressing
the MSI affinity race unearthed yet another long standing bug.

If user space writes a bogus affinity mask, i.e. it contains no online CPUs,
then it calls irq_select_affinity_usr(). This was introduced for ALPHA in

  eee45269b0 ("[PATCH] Alpha: convert to generic irq framework (generic part)")

and subsequently made available for all architectures in

  1840475676 ("genirq: Expose default irq affinity mask (take 3)")

which introduced the circumvention of the affinity setting restrictions for
interrupt which cannot be moved in process context.

The whole exercise is bogus in various aspects:

  1) If the interrupt is already started up then there is absolutely
     no point to honour a bogus interrupt affinity setting from user
     space. The interrupt is already assigned to an online CPU and it
     does not make any sense to reassign it to some other randomly
     chosen online CPU.

  2) If the interupt is not yet started up then there is no point
     either. A subsequent startup of the interrupt will invoke
     irq_setup_affinity() anyway which will chose a valid target CPU.

So the only correct solution is to just return -EINVAL in case user space
wrote an affinity mask which does not contain any online CPUs, except for
ALPHA which has it's own magic sauce for this.

Fixes: 1840475676 ("genirq: Expose default irq affinity mask (take 3)")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Qian Cai <cai@lca.pw>
Link: https://lkml.kernel.org/r/878sl8xdbm.fsf@nanos.tec.linutronix.de
2020-02-14 09:43:17 +01:00
Rafael J. Wysocki
e033b6c175 PM: QoS: Adjust pm_qos_request() signature and reorder pm_qos.h
Change the return type of pm_qos_request() to be the same as the
one of pm_qos_read_value() called by it internally and stop exporting
it to modules (because its only caller, cpuidle, is not modular).

Also move the pm_qos_read_value() header away from the CPU latency
QoS API function headers in pm_qos.h (because it technically does
not belong to that API).

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:26:46 +01:00
Rafael J. Wysocki
333eed7d20 PM: QoS: Simplify definitions of CPU latency QoS trace events
Modify the definitions of the CPU latency QoS trace events to take
one argument (since PM_QOS_CPU_DMA_LATENCY is always passed as the
pm_qos_class argument to them) and update the documentation of them
accordingly (while at it, make it explicitly mention CPU latency QoS
and relocate it after the device PM QoS trace events documentation).

The names and output format of the trace events do not change to
preserve user space compatibility.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:26:39 +01:00
Rafael J. Wysocki
2552d35201 PM: QoS: Rename things related to the CPU latency QoS
First, rename PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE to
PM_QOS_CPU_LATENCY_DEFAULT_VALUE and update all of the code
referring to it accordingly.

Next, rename cpu_dma_constraints to cpu_latency_constraints, move
the definition of it closer to the functions referring to it and
update all of them accordingly.  [While at it, add a comment to mark
the start of the code related to the CPU latency QoS.]

Finally, rename the pm_qos_power_*() family of functions and
pm_qos_power_fops to cpu_latency_qos_*() and cpu_latency_qos_fops,
respectively, and update the definition of cpu_latency_qos_miscdev.
[While at it, update the miscdev interface code start comment.]

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:26:33 +01:00
Rafael J. Wysocki
3a4a004222 PM: QoS: Drop PM_QOS_CPU_DMA_LATENCY notifier chain
Notice that pm_qos_remove_notifier() is not used at all and the only
caller of pm_qos_add_notifier() is the cpuidle core, which only needs
the PM_QOS_CPU_DMA_LATENCY notifier to invoke wake_up_all_idle_cpus()
upon changes of the PM_QOS_CPU_DMA_LATENCY target value.

First, to ensure that wake_up_all_idle_cpus() will be called
whenever the PM_QOS_CPU_DMA_LATENCY target value changes, modify the
pm_qos_add/update/remove_request() family of functions to check if
the effective constraint for the PM_QOS_CPU_DMA_LATENCY has changed
and call wake_up_all_idle_cpus() directly in that case.

Next, drop the PM_QOS_CPU_DMA_LATENCY notifier from cpuidle as it is
not necessary any more.

Finally, drop both pm_qos_add_notifier() and pm_qos_remove_notifier(),
as they have no callers now, along with cpu_dma_lat_notifier which is
only used by them.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:26:27 +01:00
Rafael J. Wysocki
02c92a3789 PM: QoS: Redefine struct pm_qos_request and drop struct pm_qos_object
First, change the definition of struct pm_qos_request so that it
contains a struct pm_qos_constraints pointer (called "qos") instead
of a PM QoS class number (in preparation for dropping the PM QoS
classes concept altogether going forward) and move its definition
(along with the definition of struct pm_qos_flags_request that does
not change) after the definition of struct pm_qos_constraints.

Next, drop the definition of struct pm_qos_object and the null_pm_qos
and cpu_dma_pm_qos variables of that type along with pm_qos_array[]
holding pointers to them and change the code to refer to the
pm_qos_constraints structure directly or to use the new qos pointer
in struct pm_qos_request for that instead of going through
pm_qos_array[] to access it.  Also update kerneldoc comments that
mention pm_qos_class to refer to PM_QOS_CPU_DMA_LATENCY directly
instead.

Finally, drop register_pm_qos_misc(), introduce cpu_latency_qos_miscdev
(with the name field set to "cpu_dma_latency") to implement the
CPU latency QoS interface in /dev/ and register it directly from
pm_qos_power_init().

After these changes the notion of PM QoS classes remains only in the
API (in the form of redundant function parameters that are ignored)
and in the definitions of PM QoS trace events.

While at it, some redundant local variables are dropped etc.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:26:19 +01:00
Rafael J. Wysocki
299a229830 PM: QoS: Clean up misc device file operations
Reorder the code to avoid using extra function header declarations
for the pm_qos_power_*() family of functions and drop those
declarations.

Also clean up the internals of those functions to consolidate checks,
avoid using redundant local variables and similar.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:26:13 +01:00
Rafael J. Wysocki
63cffc0534 PM: QoS: Drop iterations over global QoS classes
After commit c3082a674f ("PM: QoS: Get rid of unused flags") the
only global PM QoS class in use is PM_QOS_CPU_DMA_LATENCY, so it
does not really make sense to iterate over global QoS classes
anywhere, since there is only one.

Remove iterations over global QoS classes from the code and use
PM_QOS_CPU_DMA_LATENCY as the target class directly where needed.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:26:07 +01:00
Rafael J. Wysocki
dcd70ca1a3 PM: QoS: Clean up pm_qos_read_value() and pm_qos_get/set_value()
Move the definition of pm_qos_read_value() before the one of
pm_qos_get_value() and add a kerneldoc comment to it (as it is
not static).

Also replace the BUG() in pm_qos_get_value() with WARN() (to
prevent the kernel from crashing if an unknown PM QoS type is
used by mistake) and drop the comment next to it that is not
necessary any more.

Additionally, drop the unnecessary inline modifier from the header
of pm_qos_set_value().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:26:02 +01:00
Rafael J. Wysocki
7b35370b2e PM: QoS: Clean up pm_qos_update_target() and pm_qos_update_flags()
Clean up the pm_qos_update_target() function:
 * Update its kerneldoc comment.
 * Drop the redundant ret local variable from it.
 * Reorder definitions of local variables in it.
 * Update a comment in it.

Also update the kerneldoc comment of pm_qos_update_flags() (e.g.
notifiers are not called by it any more) and add one emtpy line
to its body (for more visual clarity).

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:25:55 +01:00
Rafael J. Wysocki
87ad735679 PM: QoS: Drop the PM_QOS_SUM QoS type
The PM_QOS_SUM QoS type is not used, so drop it along with the
code referring to it in pm_qos_get_value() and the related local
variables in there.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:25:48 +01:00
Rafael J. Wysocki
5a7ea52b6f PM: QoS: Drop pm_qos_update_request_timeout()
The pm_qos_update_request_timeout() function is not called from
anywhere, so drop it along with the work member in struct
pm_qos_request needed by it.

Also drop the useless pm_qos_update_request_timeout trace event
that is only triggered by that function (so it never triggers at
all) and update the trace events documentation accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Tested-by: Amit Kucheria <amit.kucheria@linaro.org>
2020-02-13 11:25:40 +01:00
Christian Brauner
ef2c41cf38 clone3: allow spawning processes into cgroups
This adds support for creating a process in a different cgroup than its
parent. Callers can limit and account processes and threads right from
the moment they are spawned:
- A service manager can directly spawn new services into dedicated
  cgroups.
- A process can be directly created in a frozen cgroup and will be
  frozen as well.
- The initial accounting jitter experienced by process supervisors and
  daemons is eliminated with this.
- Threaded applications or even thread implementations can choose to
  create a specific cgroup layout where each thread is spawned
  directly into a dedicated cgroup.

This feature is limited to the unified hierarchy. Callers need to pass
a directory file descriptor for the target cgroup. The caller can
choose to pass an O_PATH file descriptor. All usual migration
restrictions apply, i.e. there can be no processes in inner nodes. In
general, creating a process directly in a target cgroup adheres to all
migration restrictions.

One of the biggest advantages of this feature is that CLONE_INTO_GROUP does
not need to grab the write side of the cgroup cgroup_threadgroup_rwsem.
This global lock makes moving tasks/threads around super expensive. With
clone3() this lock is avoided.

Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: cgroups@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 17:57:51 -05:00
Christian Brauner
f3553220d4 cgroup: add cgroup_may_write() helper
Add a cgroup_may_write() helper which we can use in the
CLONE_INTO_CGROUP patch series to verify that we can write to the
destination cgroup.

Cc: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: cgroups@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 17:57:51 -05:00
Christian Brauner
5a5cf5cb30 cgroup: refactor fork helpers
This refactors the fork helpers so they can be easily modified in the
next patches. The patch just moves the cgroup threadgroup rwsem grab and
release into the helpers. They don't need to be directly exposed in fork.c.

Cc: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: cgroups@vger.kernel.org
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 17:57:51 -05:00
Christian Brauner
17703097f3 cgroup: add cgroup_get_from_file() helper
Add a helper cgroup_get_from_file(). The helper will be used in
subsequent patches to retrieve a cgroup while holding a reference to the
struct file it was taken from.

Cc: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: cgroups@vger.kernel.org
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 17:57:51 -05:00
Christian Brauner
6df970e4f5 cgroup: unify attach permission checking
The core codepaths to check whether a process can be attached to a
cgroup are the same for threads and thread-group leaders. Only a small
piece of code verifying that source and destination cgroup are in the
same domain differentiates the thread permission checking from
thread-group leader permission checking.
Since cgroup_migrate_vet_dst() only matters cgroup2 - it is a noop on
cgroup1 - we can move it out of cgroup_attach_task().
All checks can now be consolidated into a new helper
cgroup_attach_permissions() callable from both cgroup_procs_write() and
cgroup_threads_write().

Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: cgroups@vger.kernel.org
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 17:57:51 -05:00
Prateek Sood
a49e4629b5 cpuset: Make cpuset hotplug synchronous
Convert cpuset_hotplug_workfn() into synchronous call for cpu hotplug
path. For memory hotplug path it still gets queued as a work item.

Since cpuset_hotplug_workfn() can be made synchronous for cpu hotplug
path, it is not required to wait for cpuset hotplug while thawing
processes.

Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 17:13:47 -05:00
Madhuparna Bhowmik
3010c5b9f5 cgroup.c: Use built-in RCU list checking
list_for_each_entry_rcu has built-in RCU and lock checking.
Pass cond argument to list_for_each_entry_rcu() to silence
false lockdep warning when  CONFIG_PROVE_RCU_LIST is enabled
by default.

Even though the function css_next_child() already checks if
cgroup_mutex or rcu_read_lock() is held using
cgroup_assert_mutex_or_rcu_locked(), there is a need to pass
cond to list_for_each_entry_rcu() to avoid false positive
lockdep warning.

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 17:12:22 -05:00
Michal Koutný
f43caa2adc cgroup: Clean up css_set task traversal
css_task_iter stores pointer to head of each iterable list, this dates
back to commit 0f0a2b4fa6 ("cgroup: reorganize css_task_iter") when we
did not store cur_cset. Let us utilize list heads directly in cur_cset
and streamline css_task_iter_advance_css_set a bit. This is no
intentional function change.

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 17:11:52 -05:00
Michal Koutný
9c974c7724 cgroup: Iterate tasks that did not finish do_exit()
PF_EXITING is set earlier than actual removal from css_set when a task
is exitting. This can confuse cgroup.procs readers who see no PF_EXITING
tasks, however, rmdir is checking against css_set membership so it can
transitionally fail with EBUSY.

Fix this by listing tasks that weren't unlinked from css_set active
lists.
It may happen that other users of the task iterator (without
CSS_TASK_ITER_PROCS) spot a PF_EXITING task before cgroup_exit(). This
is equal to the state before commit c03cd7738a ("cgroup: Include dying
leaders with live threads in PROCS iterations") but it may be reviewed
later.

Reported-by: Suren Baghdasaryan <surenb@google.com>
Fixes: c03cd7738a ("cgroup: Include dying leaders with live threads in PROCS iterations")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 17:02:53 -05:00
Vasily Averin
2d4ecb030d cgroup: cgroup_procs_next should increase position index
If seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output:

1) dd bs=1 skip output of each 2nd elements
$ dd if=/sys/fs/cgroup/cgroup.procs bs=8 count=1
2
3
4
5
1+0 records in
1+0 records out
8 bytes copied, 0,000267297 s, 29,9 kB/s
[test@localhost ~]$ dd if=/sys/fs/cgroup/cgroup.procs bs=1 count=8
2
4 <<< NB! 3 was skipped
6 <<<    ... and 5 too
8 <<<    ... and 7
8+0 records in
8+0 records out
8 bytes copied, 5,2123e-05 s, 153 kB/s

 This happen because __cgroup_procs_start() makes an extra
 extra cgroup_procs_next() call

2) read after lseek beyond end of file generates whole last line.
3) read after lseek into middle of last line generates
expected rest of last line and unexpected whole line once again.

Additionally patch removes an extra position index changes in
__cgroup_procs_start()

Cc: stable@vger.kernel.org
https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 17:00:04 -05:00
Vasily Averin
db8dd96972 cgroup-v1: cgroup_pidlist_next should update position index
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

 # mount | grep cgroup
 # dd if=/mnt/cgroup.procs bs=1  # normal output
...
1294
1295
1296
1304
1382
584+0 records in
584+0 records out
584 bytes copied

dd: /mnt/cgroup.procs: cannot skip to specified offset
83  <<< generates end of last line
1383  <<< ... and whole last line once again
0+1 records in
0+1 records out
8 bytes copied

dd: /mnt/cgroup.procs: cannot skip to specified offset
1386  <<< generates last line anyway
0+1 records in
0+1 records out
5 bytes copied

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-02-12 16:53:35 -05:00
Rafael J. Wysocki
3489662042 PM: QoS: Drop debugfs interface
After commit c3082a674f ("PM: QoS: Get rid of unused flags") the
only global PM QoS class in use is PM_QOS_CPU_DMA_LATENCY and the
existing PM QoS debugfs interface has become overly complicated (as
it takes other potentially possible PM QoS classes that are not there
any more into account).  It is also not particularly useful (the
"type" of the PM_QOS_CPU_DMA_LATENCY is known, its aggregate value
can be read from /dev/cpu_dma_latency and the number of requests in
the queue does not really matter) and there are no known users
depending on it.  Moreover, there are dedicated trace events that
can be used for tracking PM QoS usage with much higher precision.

For these reasons, drop the PM QoS debugfs interface altogether.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2020-02-12 10:28:42 +01:00
Linus Torvalds
61a7595403 Various fixes:
- Fix an uninitialized variable
 
  - Fix compile bug to bootconfig userspace tool (in tools directory)
 
  - Suppress some error messages of bootconfig userspace tool
 
  - Remove unneded CONFIG_LIBXBC from bootconfig
 
  - Allocate bootconfig xbc_nodes dynamically.
    To ease complaints about taking up static memory at boot up
 
  - Use of parse_args() to parse bootconfig instead of strstr() usage
    Prevents issues of double quotes containing the interested string
 
  - Fix missing ring_buffer_nest_end() on synthetic event error path
 
  - Return zero not -EINVAL on soft disabled synthetic event
    (soft disabling must be the same as hard disabling, which returns zero)
 
  - Consolidate synthetic event code (remove duplicate code)
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Merge tag 'trace-v5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Various fixes:

   - Fix an uninitialized variable

   - Fix compile bug to bootconfig userspace tool (in tools directory)

   - Suppress some error messages of bootconfig userspace tool

   - Remove unneded CONFIG_LIBXBC from bootconfig

   - Allocate bootconfig xbc_nodes dynamically. To ease complaints about
     taking up static memory at boot up

   - Use of parse_args() to parse bootconfig instead of strstr() usage
     Prevents issues of double quotes containing the interested string

   - Fix missing ring_buffer_nest_end() on synthetic event error path

   - Return zero not -EINVAL on soft disabled synthetic event (soft
     disabling must be the same as hard disabling, which returns zero)

   - Consolidate synthetic event code (remove duplicate code)"

* tag 'trace-v5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Consolidate trace() functions
  tracing: Don't return -EINVAL when tracing soft disabled synth events
  tracing: Add missing nest end to synth_event_trace_start() error case
  tools/bootconfig: Suppress non-error messages
  bootconfig: Allocate xbc_nodes array dynamically
  bootconfig: Use parse_args() to find bootconfig and '--'
  tracing/kprobe: Fix uninitialized variable bug
  bootconfig: Remove unneeded CONFIG_LIBXBC
  tools/bootconfig: Fix wrong __VA_ARGS__ usage
2020-02-11 16:39:18 -08:00
Kan Liang
bbfd5e4fab perf/core: Add new branch sample type for HW index of raw branch records
The low level index is the index in the underlying hardware buffer of
the most recently captured taken branch which is always saved in
branch_entries[0]. It is very useful for reconstructing the call stack.
For example, in Intel LBR call stack mode, the depth of reconstructed
LBR call stack limits to the number of LBR registers. With the low level
index information, perf tool may stitch the stacks of two samples. The
reconstructed LBR call stack can break the HW limitation.

Add a new branch sample type to retrieve low level index of raw branch
records. The low level index is between -1 (unknown) and max depth which
can be retrieved in /sys/devices/cpu/caps/branches.

Only when the new branch sample type is set, the low level index
information is dumped into the PERF_SAMPLE_BRANCH_STACK output.
Perf tool should check the attr.branch_sample_type, and apply the
corresponding format for PERF_SAMPLE_BRANCH_STACK samples.
Otherwise, some user case may be broken. For example, users may parse a
perf.data, which include the new branch sample type, with an old version
perf tool (without the check). Users probably get incorrect information
without any warning.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200127165355.27495-2-kan.liang@linux.intel.com
2020-02-11 13:23:49 +01:00
Davidlohr Bueso
41f0e29190 locking/percpu-rwsem: Add might_sleep() for writer locking
We are missing this annotation in percpu_down_write(). Correct
this.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/20200108013305.7732-1-dave@stgolabs.net
2020-02-11 13:11:02 +01:00
Davidlohr Bueso
ac8dec4209 locking/percpu-rwsem: Fold __percpu_up_read()
Now that __percpu_up_read() is only ever used from percpu_up_read()
merge them, it's a small function.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/20200131151540.212415454@infradead.org
2020-02-11 13:10:58 +01:00
Peter Zijlstra
bcba67cd80 locking/rwsem: Remove RWSEM_OWNER_UNKNOWN
Remove the now unused RWSEM_OWNER_UNKNOWN hack. This hack breaks
PREEMPT_RT and getting rid of it was the entire motivation for
re-writing the percpu rwsem.

The biggest problem is that it is fundamentally incompatible with any
form of Priority Inheritance, any exclusively held lock must have a
distinct owner.

Requested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200204092228.GP14946@hirez.programming.kicks-ass.net
2020-02-11 13:10:57 +01:00
Peter Zijlstra
7f26482a87 locking/percpu-rwsem: Remove the embedded rwsem
The filesystem freezer uses percpu-rwsem in a way that is effectively
write_non_owner() and achieves this with a few horrible hacks that
rely on the rwsem (!percpu) implementation.

When PREEMPT_RT replaces the rwsem implementation with a PI aware
variant this comes apart.

Remove the embedded rwsem and implement it using a waitqueue and an
atomic_t.

 - make readers_block an atomic, and use it, with the waitqueue
   for a blocking test-and-set write-side.

 - have the read-side wait for the 'lock' state to clear.

Have the waiters use FIFO queueing and mark them (reader/writer) with
a new WQ_FLAG. Use a custom wake_function to wake either a single
writer or all readers until a writer.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200204092403.GB14879@hirez.programming.kicks-ass.net
2020-02-11 13:10:56 +01:00
Peter Zijlstra
75ff64572e locking/percpu-rwsem: Extract __percpu_down_read_trylock()
In preparation for removing the embedded rwsem and building a custom
lock, extract the read-trylock primitive.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200131151540.098485539@infradead.org
2020-02-11 13:10:55 +01:00
Peter Zijlstra
71365d4023 locking/percpu-rwsem: Move __this_cpu_inc() into the slowpath
As preparation to rework __percpu_down_read() move the
__this_cpu_inc() into it.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200131151540.041600199@infradead.org
2020-02-11 13:10:54 +01:00
Peter Zijlstra
206c98ffbe locking/percpu-rwsem: Convert to bool
Use bool where possible.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200131151539.984626569@infradead.org
2020-02-11 13:10:54 +01:00
Peter Zijlstra
1751060e25 locking/percpu-rwsem, lockdep: Make percpu-rwsem use its own lockdep_map
As preparation for replacing the embedded rwsem, give percpu-rwsem its
own lockdep_map.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/20200131151539.927625541@infradead.org
2020-02-11 13:10:53 +01:00
Waiman Long
810507fe6f locking/lockdep: Reuse freed chain_hlocks entries
Once a lock class is zapped, all the lock chains that include the zapped
class are essentially useless. The lock_chain structure itself can be
reused, but not the corresponding chain_hlocks[] entries. Over time,
we will run out of chain_hlocks entries while there are still plenty
of other lockdep array entries available.

To fix this imbalance, we have to make chain_hlocks entries reusable
just like the others. As the freed chain_hlocks entries are in blocks of
various lengths. A simple bitmap like the one used in the other reusable
lockdep arrays isn't applicable. Instead the chain_hlocks entries are
put into bucketed lists (MAX_CHAIN_BUCKETS) of chain blocks.  Bucket 0
is the variable size bucket which houses chain blocks of size larger than
MAX_CHAIN_BUCKETS sorted in decreasing size order.  Initially, the whole
array is in one chain block (the primordial chain block) in bucket 0.

The minimum size of a chain block is 2 chain_hlocks entries. That will
be the minimum allocation size. In other word, allocation requests
for one chain_hlocks entry will cause 2-entry block to be returned and
hence 1 entry will be wasted.

Allocation requests for the chain_hlocks are fulfilled first by looking
for chain block of matching size. If not found, the first chain block
from bucket[0] (the largest one) is split. That can cause hlock entries
fragmentation and reduce allocation efficiency if a chain block of size >
MAX_CHAIN_BUCKETS is ever zapped and put back to after the primordial
chain block. So the MAX_CHAIN_BUCKETS must be large enough that this
should seldom happen.

By reusing the chain_hlocks entries, we are able to handle workloads
that add and zap a lot of lock classes without the risk of running out
of chain_hlocks entries as long as the total number of outstanding lock
classes at any time remain within a reasonable limit.

Two new tracking counters, nr_free_chain_hlocks & nr_large_chain_blocks,
are added to track the total number of chain_hlocks entries in the
free bucketed lists and the number of large chain blocks in buckets[0]
respectively. The nr_free_chain_hlocks replaces nr_chain_hlocks.

The nr_large_chain_blocks counter enables to see if we should increase
the number of buckets (MAX_CHAIN_BUCKETS) available so as to avoid to
avoid the fragmentation problem in bucket[0].

An internal nfsd test that ran for more than an hour and kept on
loading and unloading kernel modules could cause the following message
to be displayed.

  [ 4318.443670] BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!

The patched kernel was able to complete the test with a lot of free
chain_hlocks entries to spare:

  # cat /proc/lockdep_stats
     :
   dependency chains:                   18867 [max: 65536]
   dependency chain hlocks:             74926 [max: 327680]
   dependency chain hlocks lost:            0
     :
   zapped classes:                       1541
   zapped lock chains:                  56765
   large chain blocks:                      1

By changing MAX_CHAIN_BUCKETS to 3 and add a counter for the size of the
largest chain block. The system still worked and We got the following
lockdep_stats data:

   dependency chains:                   18601 [max: 65536]
   dependency chain hlocks used:        73133 [max: 327680]
   dependency chain hlocks lost:            0
     :
   zapped classes:                       1541
   zapped lock chains:                  56702
   large chain blocks:                  45165
   large chain block size:              20165

By running the test again, I was indeed able to cause chain_hlocks
entries to get lost:

   dependency chain hlocks used:        74806 [max: 327680]
   dependency chain hlocks lost:          575
     :
   large chain blocks:                  48737
   large chain block size:                  7

Due to the fragmentation, it is possible that the
"MAX_LOCKDEP_CHAIN_HLOCKS too low!" error can happen even if a lot of
of chain_hlocks entries appear to be free.

Fortunately, a MAX_CHAIN_BUCKETS value of 16 should be big enough that
few variable sized chain blocks, other than the initial one, should
ever be present in bucket 0.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200206152408.24165-7-longman@redhat.com
2020-02-11 13:10:52 +01:00
Waiman Long
797b82eb90 locking/lockdep: Track number of zapped lock chains
Add a new counter nr_zapped_lock_chains to track the number lock chains
that have been removed.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200206152408.24165-6-longman@redhat.com
2020-02-11 13:10:51 +01:00
Waiman Long
836bd74b59 locking/lockdep: Throw away all lock chains with zapped class
If a lock chain contains a class that is zapped, the whole lock chain is
likely to be invalid. If the zapped class is at the end of the chain,
the partial chain without the zapped class should have been stored
already as the current code will store all its predecessor chains. If
the zapped class is somewhere in the middle, there is no guarantee that
the partial chain will actually happen. It may just clutter up the hash
and make searching slower. I would rather prefer storing the chain only
when it actually happens.

So just dump the corresponding chain_hlocks entries for now. A latter
patch will try to reuse the freed chain_hlocks entries.

This patch also changes the type of nr_chain_hlocks to unsigned integer
to be consistent with the other counters.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200206152408.24165-5-longman@redhat.com
2020-02-11 13:10:50 +01:00
Waiman Long
1d44bcb4fd locking/lockdep: Track number of zapped classes
The whole point of the lockdep dynamic key patch is to allow unused
locks to be removed from the lockdep data buffers so that existing
buffer space can be reused. However, there is no way to find out how
many unused locks are zapped and so we don't know if the zapping process
is working properly.

Add a new nr_zapped_classes counter to track that and show it in
/proc/lockdep_stats.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200206152408.24165-4-longman@redhat.com
2020-02-11 13:10:49 +01:00
Waiman Long
b9875e9882 locking/lockdep: Display irq_context names in /proc/lockdep_chains
Currently, the irq_context field of a lock chains displayed in
/proc/lockdep_chains is just a number. It is likely that many people
may not know what a non-zero number means. To make the information more
useful, print the actual irq names ("softirq" and "hardirq") instead.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200206152408.24165-3-longman@redhat.com
2020-02-11 13:10:48 +01:00
Waiman Long
b3b9c187dc locking/lockdep: Decrement IRQ context counters when removing lock chain
There are currently three counters to track the IRQ context of a lock
chain - nr_hardirq_chains, nr_softirq_chains and nr_process_chains.
They are incremented when a new lock chain is added, but they are
not decremented when a lock chain is removed. That causes some of the
statistic counts reported by /proc/lockdep_stats to be incorrect.
IRQ
Fix that by decrementing the right counter when a lock chain is removed.

Since inc_chains() no longer accesses hardirq_context and softirq_context
directly, it is moved out from the CONFIG_TRACE_IRQFLAGS conditional
compilation block.

Fixes: a0b0fd53e1 ("locking/lockdep: Free lock classes that are no longer in use")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200206152408.24165-2-longman@redhat.com
2020-02-11 13:10:48 +01:00
Randy Dunlap
e9f5490c35 sched/fair: Fix kernel-doc warning in attach_entity_load_avg()
Fix kernel-doc warning in kernel/sched/fair.c, caused by a recent
function parameter removal:

  ../kernel/sched/fair.c:3526: warning: Excess function parameter 'flags' description in 'attach_entity_load_avg'

Fixes: a4f9a0e51b ("sched/fair: Remove redundant call to cpufreq_update_util()")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/cbe964e4-6879-fd08-41c9-ef1917414af4@infradead.org
2020-02-11 13:05:10 +01:00
Madhuparna Bhowmik
4104a562e0 sched/core: Annotate curr pointer in rq with __rcu
This patch fixes the following sparse warnings in sched/core.c
and sched/membarrier.c:

  kernel/sched/core.c:2372:27: error: incompatible types in comparison expression
  kernel/sched/core.c:4061:17: error: incompatible types in comparison expression
  kernel/sched/core.c:6067:9: error: incompatible types in comparison expression
  kernel/sched/membarrier.c:108:21: error: incompatible types in comparison expression
  kernel/sched/membarrier.c:177:21: error: incompatible types in comparison expression
  kernel/sched/membarrier.c:243:21: error: incompatible types in comparison expression

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200201125803.20245-1-madhuparnabhowmik10@gmail.com
2020-02-11 13:00:37 +01:00
Suren Baghdasaryan
6fcca0fa48 sched/psi: Fix OOB write when writing 0 bytes to PSI files
Issuing write() with count parameter set to 0 on any file under
/proc/pressure/ will cause an OOB write because of the access to
buf[buf_size-1] when NUL-termination is performed. Fix this by checking
for buf_size to be non-zero.

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lkml.kernel.org/r/20200203212216.7076-1-surenb@google.com
2020-02-11 13:00:02 +01:00
Andy Shevchenko
ed31685c96 console: Introduce ->exit() callback
Some consoles might require special operations on unregistering.
For instance, serial console, when registered in the kernel,
keeps power on for entire time, until it gets unregistered.
Example of use:

	->setup(console):
		pm_runtime_get(...);

	->exit(console):
		pm_runtime_put(...);

For such cases to have a balance we would provide ->exit() callback.

Link: http://lkml.kernel.org/r/20200203133130.11591-7-andriy.shevchenko@linux.intel.com
To: linux-kernel@vger.kernel.org
To: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11 10:44:22 +01:00
Andy Shevchenko
e78bedbd42 console: Don't notify user space when unregister non-listed console
If console is not on the list then there is nothing for us to do
and sysfs notify is pointless.

Note, that nr_ext_console_drivers is being changed only for listed
consoles.

Suggested-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Link: http://lkml.kernel.org/r/20200203133130.11591-6-andriy.shevchenko@linux.intel.com
To: linux-kernel@vger.kernel.org
To: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11 10:44:17 +01:00
Andy Shevchenko
bb72e3981d console: Avoid positive return code from unregister_console()
There are only two callers that use the returned code from
unregister_console():

  - unregister_early_console() in arch/m68k/kernel/early_printk.c
  - kgdb_unregister_nmi_console() in drivers/tty/serial/kgdb_nmi.c

They both expect to get "0" on success and a non-zero value on error.
But the current behavior is confusing and buggy:

  - _braille_unregister_console() returns "1" on success
  - unregister_console() returns "1" on error

Fix and clean up the behavior:

  - Return success when _braille_unregister_console() succeeded
  - Return a meaningful error code when the console was
    not registered before

Link: http://lkml.kernel.org/r/20200203133130.11591-5-andriy.shevchenko@linux.intel.com
To: linux-kernel@vger.kernel.org
To: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11 10:44:12 +01:00
Andy Shevchenko
d58ad10122 console: Drop misleading comment
/* find the last or real console */

This comment is misleading. The purpose of the loop is to check
if we are trying to register boot console after a real one has
already been registered. This is already mentioned in a comment
above.

Link: http://lkml.kernel.org/r/20200203133130.11591-4-andriy.shevchenko@linux.intel.com
To: linux-kernel@vger.kernel.org
To: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[pmladek@suse.com: Updated commit message.]
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11 10:44:02 +01:00
Andy Shevchenko
12825e6ba8 console: Use for_each_console() helper in unregister_console()
We have rather open coded single linked list manipulations where we may
simple use for_each_console() helper with properly set exit conditions.

Replace open coded single-linked list handling with for_each_console()
helper in use.

Link: http://lkml.kernel.org/r/20200203133130.11591-3-andriy.shevchenko@linux.intel.com
To: linux-kernel@vger.kernel.org
To: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11 10:43:56 +01:00
Andy Shevchenko
caa72c3bc5 console: Drop double check for console_drivers being non-NULL
There is no need to explicitly check for console_drivers to be non-NULL
since for_each_console() does this.

Link: http://lkml.kernel.org/r/20200203133130.11591-2-andriy.shevchenko@linux.intel.com
To: linux-kernel@vger.kernel.org
To: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-02-11 10:43:42 +01:00
Rafael J. Wysocki
e3728b50cd ACPI: PM: s2idle: Avoid possible race related to the EC GPE
It is theoretically possible for the ACPI EC GPE to be set after the
s2idle_ops->wake() called from s2idle_loop() has returned and before
the subsequent pm_wakeup_pending() check is carried out.  If that
happens, the resulting wakeup event will cause the system to resume
even though it may be a spurious one.

To avoid that race, first make the ->wake() callback in struct
platform_s2idle_ops return a bool value indicating whether or not
to let the system resume and rearrange s2idle_loop() to use that
value instad of the direct pm_wakeup_pending() call if ->wake() is
present.

Next, rework acpi_s2idle_wake() to process EC events and check
pm_wakeup_pending() before re-arming the SCI for system wakeup
to prevent it from triggering prematurely and add comments to
that function to explain the rationale for the new code flow.

Fixes: 56b9918490 ("PM: sleep: Simplify suspend-to-idle control flow")
Cc: 5.4+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-02-11 10:11:02 +01:00
Tom Zanussi
7276531d40 tracing: Consolidate trace() functions
Move the checking, buffer reserve and buffer commit code in
synth_event_trace_start/end() into inline functions
__synth_event_trace_start/end() so they can also be used by
synth_event_trace() and synth_event_trace_array(), and then have all
those functions use them.

Also, change synth_event_trace_state.enabled to disabled so it only
needs to be set if the event is disabled, which is not normally the
case.

Link: http://lkml.kernel.org/r/b1f3108d0f450e58192955a300e31d0405ab4149.1581374549.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-10 22:00:21 -05:00
Tom Zanussi
0c62f6cd9e tracing: Don't return -EINVAL when tracing soft disabled synth events
There's no reason to return -EINVAL when tracing a synthetic event if
it's soft disabled - treat it the same as if it were hard disabled and
return normally.

Have synth_event_trace() and synth_event_trace_array() just return
normally, and have synth_event_trace_start set the trace state to
disabled and return.

Link: http://lkml.kernel.org/r/df5d02a1625aff97c9866506c5bada6a069982ba.1581374549.git.zanussi@kernel.org

Fixes: 8dcc53ad95 ("tracing: Add synth_event_trace() and related functions")
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-10 22:00:13 -05:00
Tom Zanussi
d090409abb tracing: Add missing nest end to synth_event_trace_start() error case
If the ring_buffer reserve in synth_event_trace_start() fails, the
matching ring_buffer_nest_end() should be called in the error code,
since nothing else will ever call it in this case.

Link: http://lkml.kernel.org/r/20abc444b3eeff76425f895815380abe7aa53ff8.1581374549.git.zanussi@kernel.org

Fixes: 8dcc53ad95 ("tracing: Add synth_event_trace() and related functions")
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-10 21:58:19 -05:00
Linus Torvalds
0a679e13ea Merge branch 'for-5.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
 "I made a mistake while removing cgroup task list lazy init
  optimization making the root cgroup.procs show entries for the
  init_tasks. The zero entries doesn't cause critical failures but does
  make systemd print out warning messages during boot.

  Fix it by omitting init_tasks as they should be"

* 'for-5.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: init_tasks shouldn't be linked to the root cgroup
2020-02-10 17:07:05 -08:00
Hongbo Yao
2bf0eb9b3b bpf: Make btf_check_func_type_match() static
Fix the following sparse warning:

kernel/bpf/btf.c:4131:5: warning: symbol 'btf_check_func_type_match' was
not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Hongbo Yao <yaohongbo@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200210011441.147102-1-yaohongbo@huawei.com
2020-02-11 00:22:47 +01:00
Gustavo A. R. Silva
10f129cb59 tracing/kprobe: Fix uninitialized variable bug
There is a potential execution path in which variable *ret* is returned
without being properly initialized, previously.

Fix this by initializing variable *ret* to 0.

Link: http://lkml.kernel.org/r/20200205223404.GA3379@embeddedor

Addresses-Coverity-ID: 1491142 ("Uninitialized scalar variable")
Fixes: 2a588dd1d5 ("tracing: Add kprobe event command generation functions")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-10 12:07:42 -05:00
Steve Grubb
70b3eeed49 audit: CONFIG_CHANGE don't log internal bookkeeping as an event
Common Criteria calls out for any action that modifies the audit trail to
be recorded. That usually is interpreted to mean insertion or removal of
rules. It is not required to log modification of the inode information
since the watch is still in effect. Additionally, if the rule is a never
rule and the underlying file is one they do not want events for, they
get an event for this bookkeeping update against their wishes.

Since no device/inode info is logged at insertion and no device/inode
information is logged on update, there is nothing meaningful being
communicated to the admin by the CONFIG_CHANGE updated_rules event. One
can assume that the rule was not "modified" because it is still watching
the intended target. If the device or inode cannot be resolved, then
audit_panic is called which is sufficient.

The correct resolution is to drop logging config_update events since
the watch is still in effect but just on another unknown inode.

Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-02-10 10:46:35 -05:00
Mel Gorman
52262ee567 sched/fair: Allow a per-CPU kthread waking a task to stack on the same CPU, to fix XFS performance regression
The following XFS commit:

  8ab39f11d9 ("xfs: prevent CIL push holdoff in log recovery")

changed the logic from using bound workqueues to using unbound
workqueues. Functionally this makes sense but it was observed at the
time that the dbench performance dropped quite a lot and CPU migrations
were increased.

The current pattern of the task migration is straight-forward. With XFS,
an IO issuer delegates work to xlog_cil_push_work ()on an unbound kworker.
This runs on a nearby CPU and on completion, dbench wakes up on its old CPU
as it is still idle and no migration occurs. dbench then queues the real
IO on the blk_mq_requeue_work() work item which runs on a bound kworker
which is forced to run on the same CPU as dbench. When IO completes,
the bound kworker wakes dbench but as the kworker is a bound but,
real task, the CPU is not considered idle and dbench gets migrated by
select_idle_sibling() to a new CPU. dbench may ping-pong between two CPUs
for a while but ultimately it starts a round-robin of all CPUs sharing
the same LLC. High-frequency migration on each IO completion has poor
performance overall. It has negative implications both in commication
costs and power management. mpstat confirmed that at low thread counts
that all CPUs sharing an LLC has low level of activity.

Note that even if the CIL patch was reverted, there still would
be migrations but the impact is less noticeable. It turns out that
individually the scheduler, XFS, blk-mq and workqueues all made sensible
decisions but in combination, the overall effect was sub-optimal.

This patch special cases the IO issue/completion pattern and allows
a bound kworker waker and a task wakee to stack on the same CPU if
there is a strong chance they are directly related. The expectation
is that the kworker is likely going back to sleep shortly. This is not
guaranteed as the IO could be queued asynchronously but there is a very
strong relationship between the task and kworker in this case that would
justify stacking on the same CPU instead of migrating. There should be
few concerns about kworker starvation given that the special casing is
only when the kworker is the waker.

DBench on XFS
MMTests config: io-dbench4-async modified to run on a fresh XFS filesystem

UMA machine with 8 cores sharing LLC
                          5.5.0-rc7              5.5.0-rc7
                  tipsched-20200124           kworkerstack
Amean     1        22.63 (   0.00%)       20.54 *   9.23%*
Amean     2        25.56 (   0.00%)       23.40 *   8.44%*
Amean     4        28.63 (   0.00%)       27.85 *   2.70%*
Amean     8        37.66 (   0.00%)       37.68 (  -0.05%)
Amean     64      469.47 (   0.00%)      468.26 (   0.26%)
Stddev    1         1.00 (   0.00%)        0.72 (  28.12%)
Stddev    2         1.62 (   0.00%)        1.97 ( -21.54%)
Stddev    4         2.53 (   0.00%)        3.58 ( -41.19%)
Stddev    8         5.30 (   0.00%)        5.20 (   1.92%)
Stddev    64       86.36 (   0.00%)       94.53 (  -9.46%)

NUMA machine, 48 CPUs total, 24 CPUs share cache
                           5.5.0-rc7              5.5.0-rc7
                   tipsched-20200124      kworkerstack-v1r2
Amean     1         58.69 (   0.00%)       30.21 *  48.53%*
Amean     2         60.90 (   0.00%)       35.29 *  42.05%*
Amean     4         66.77 (   0.00%)       46.55 *  30.28%*
Amean     8         81.41 (   0.00%)       68.46 *  15.91%*
Amean     16       113.29 (   0.00%)      107.79 *   4.85%*
Amean     32       199.10 (   0.00%)      198.22 *   0.44%*
Amean     64       478.99 (   0.00%)      477.06 *   0.40%*
Amean     128     1345.26 (   0.00%)     1372.64 *  -2.04%*
Stddev    1          2.64 (   0.00%)        4.17 ( -58.08%)
Stddev    2          4.35 (   0.00%)        5.38 ( -23.73%)
Stddev    4          6.77 (   0.00%)        6.56 (   3.00%)
Stddev    8         11.61 (   0.00%)       10.91 (   6.04%)
Stddev    16        18.63 (   0.00%)       19.19 (  -3.01%)
Stddev    32        38.71 (   0.00%)       38.30 (   1.06%)
Stddev    64       100.28 (   0.00%)       91.24 (   9.02%)
Stddev    128      186.87 (   0.00%)      160.34 (  14.20%)

Dbench has been modified to report the time to complete a single "load
file". This is a more meaningful metric for dbench that a throughput
metric as the benchmark makes many different system calls that are not
throughput-related

Patch shows a 9.23% and 48.53% reduction in the time to process a load
file with the difference partially explained by the number of CPUs sharing
a LLC. In a separate run, task migrations were almost eliminated by the
patch for low client counts. In case people have issue with the metric
used for the benchmark, this is a comparison of the throughputs as
reported by dbench on the NUMA machine.

dbench4 Throughput (misleading but traditional)
                           5.5.0-rc7              5.5.0-rc7
                   tipsched-20200124      kworkerstack-v1r2
Hmean     1        321.41 (   0.00%)      617.82 *  92.22%*
Hmean     2        622.87 (   0.00%)     1066.80 *  71.27%*
Hmean     4       1134.56 (   0.00%)     1623.74 *  43.12%*
Hmean     8       1869.96 (   0.00%)     2212.67 *  18.33%*
Hmean     16      2673.11 (   0.00%)     2806.13 *   4.98%*
Hmean     32      3032.74 (   0.00%)     3039.54 (   0.22%)
Hmean     64      2514.25 (   0.00%)     2498.96 *  -0.61%*
Hmean     128     1778.49 (   0.00%)     1746.05 *  -1.82%*

Note that this is somewhat specific to XFS and ext4 shows no performance
difference as it does not rely on kworkers in the same way. No major
problem was observed running other workloads on different machines although
not all tests have completed yet.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200128154006.GD3466@techsingularity.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-02-10 11:24:37 +01:00
Linus Torvalds
89a47dd1af Kbuild updates for v5.6 (2nd)
- fix randconfig to generate a sane .config
 
  - rename hostprogs-y / always to hostprogs / always-y, which are
    more natual syntax.
 
  - optimize scripts/kallsyms
 
  - fix yes2modconfig and mod2yesconfig
 
  - make multiple directory targets ('make foo/ bar/') work
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Merge tag 'kbuild-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull more Kbuild updates from Masahiro Yamada:

 - fix randconfig to generate a sane .config

 - rename hostprogs-y / always to hostprogs / always-y, which are more
   natual syntax.

 - optimize scripts/kallsyms

 - fix yes2modconfig and mod2yesconfig

 - make multiple directory targets ('make foo/ bar/') work

* tag 'kbuild-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: make multiple directory targets work
  kconfig: Invalidate all symbols after changing to y or m.
  kallsyms: fix type of kallsyms_token_table[]
  scripts/kallsyms: change table to store (strcut sym_entry *)
  scripts/kallsyms: rename local variables in read_symbol()
  kbuild: rename hostprogs-y/always to hostprogs/always-y
  kbuild: fix the document to use extra-y for vmlinux.lds
  kconfig: fix broken dependency in randconfig-generated .config
2020-02-09 16:05:50 -08:00
Linus Torvalds
1a2a76c268 A set of fixes for X86:
- Ensure that the PIT is set up when the local APIC is disable or
    configured in legacy mode. This is caused by an ordering issue
    introduced in the recent changes which skip PIT initialization when the
    TSC and APIC frequencies are already known.
 
  - Handle malformed SRAT tables during early ACPI parsing which caused an
    infinite loop anda boot hang.
 
  - Fix a long standing race in the affinity setting code which affects PCI
    devices with non-maskable MSI interrupts. The problem is caused by the
    non-atomic writes of the MSI address (destination APIC id) and data
    (vector) fields which the device uses to construct the MSI message. The
    non-atomic writes are mandated by PCI.
 
    If both fields change and the device raises an interrupt after writing
    address and before writing data, then the MSI block constructs a
    inconsistent message which causes interrupts to be lost and subsequent
    malfunction of the device.
 
    The fix is to redirect the interrupt to the new vector on the current
    CPU first and then switch it over to the new target CPU. This allows to
    observe an eventually raised interrupt in the transitional stage (old
    CPU, new vector) to be observed in the APIC IRR and retriggered on the
    new target CPU and the new vector. The potential spurious interrupts
    caused by this are harmless and can in the worst case expose a buggy
    driver (all handlers have to be able to deal with spurious interrupts as
    they can and do happen for various reasons).
 
  - Add the missing suspend/resume mechanism for the HYPERV hypercall page
    which prevents resume hibernation on HYPERV guests. This change got
    lost before the merge window.
 
  - Mask the IOAPIC before disabling the local APIC to prevent potentially
    stale IOAPIC remote IRR bits which cause stale interrupt lines after
    resume.
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Merge tag 'x86-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:
 "A set of fixes for X86:

   - Ensure that the PIT is set up when the local APIC is disable or
     configured in legacy mode. This is caused by an ordering issue
     introduced in the recent changes which skip PIT initialization when
     the TSC and APIC frequencies are already known.

   - Handle malformed SRAT tables during early ACPI parsing which caused
     an infinite loop anda boot hang.

   - Fix a long standing race in the affinity setting code which affects
     PCI devices with non-maskable MSI interrupts. The problem is caused
     by the non-atomic writes of the MSI address (destination APIC id)
     and data (vector) fields which the device uses to construct the MSI
     message. The non-atomic writes are mandated by PCI.

     If both fields change and the device raises an interrupt after
     writing address and before writing data, then the MSI block
     constructs a inconsistent message which causes interrupts to be
     lost and subsequent malfunction of the device.

     The fix is to redirect the interrupt to the new vector on the
     current CPU first and then switch it over to the new target CPU.
     This allows to observe an eventually raised interrupt in the
     transitional stage (old CPU, new vector) to be observed in the APIC
     IRR and retriggered on the new target CPU and the new vector.

     The potential spurious interrupts caused by this are harmless and
     can in the worst case expose a buggy driver (all handlers have to
     be able to deal with spurious interrupts as they can and do happen
     for various reasons).

   - Add the missing suspend/resume mechanism for the HYPERV hypercall
     page which prevents resume hibernation on HYPERV guests. This
     change got lost before the merge window.

   - Mask the IOAPIC before disabling the local APIC to prevent
     potentially stale IOAPIC remote IRR bits which cause stale
     interrupt lines after resume"

* tag 'x86-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Mask IOAPIC entries when disabling the local APIC
  x86/hyperv: Suspend/resume the hypercall page for hibernation
  x86/apic/msi: Plug non-maskable MSI affinity race
  x86/boot: Handle malformed SRAT tables during early ACPI parsing
  x86/timer: Don't skip PIT setup when APIC is disabled or in legacy mode
2020-02-09 12:11:12 -08:00
Linus Torvalds
f41377609a Two fixes for the SMP related functionality:
- Make the UP version of smp_call_function_single() match SMP semantics
    when called for a not available CPU.  Instead of emitting a warning and
    assuming that the function call target is CPU0, return a proper error
    code like the SMP version does.
 
  - Remove a superfluous check in smp_call_function_many_cond()
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Merge tag 'smp-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull SMP fixes from Thomas Gleixner:
 "Two fixes for the SMP related functionality:

   - Make the UP version of smp_call_function_single() match SMP
     semantics when called for a not available CPU. Instead of emitting
     a warning and assuming that the function call target is CPU0,
     return a proper error code like the SMP version does.

   - Remove a superfluous check in smp_call_function_many_cond()"

* tag 'smp-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp/up: Make smp_call_function_single() match SMP semantics
  smp: Remove superfluous cond_func check in smp_call_function_many_cond()
2020-02-09 12:09:43 -08:00
Linus Torvalds
ca21b9b370 A set of fixes and improvements for the perf subsystem:
- Kernel fixes:
 
    - Install cgroup events to the correct CPU context to prevent a
      potential list double add
 
    - Prevent am intgeer underflow in the perf mlock acounting
 
    - Add a missing prototyp for arch_perf_update_userpage()
 
  - Tooling:
 
    - Add a missing unlock in the error path of maps__insert() in perf maps.
 
    - Fix the build with the latest libbfd
 
    - Fix the perf parser so it does not delete parse event terms, which
      caused a regression for using perf with the ARM CoreSight as the sink
      confuguration was missing due to the deletion.
 
    - Fix the double free in the perf CPU map merging test case
 
    - Add the missing ustring support for the perf probe command
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Merge tag 'perf-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Thomas Gleixner:
 "A set of fixes and improvements for the perf subsystem:

  Kernel fixes:

   - Install cgroup events to the correct CPU context to prevent a
     potential list double add

   - Prevent an integer underflow in the perf mlock accounting

   - Add a missing prototype for arch_perf_update_userpage()

  Tooling:

   - Add a missing unlock in the error path of maps__insert() in perf
     maps.

   - Fix the build with the latest libbfd

   - Fix the perf parser so it does not delete parse event terms, which
     caused a regression for using perf with the ARM CoreSight as the
     sink configuration was missing due to the deletion.

   - Fix the double free in the perf CPU map merging test case

   - Add the missing ustring support for the perf probe command"

* tag 'perf-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf maps: Add missing unlock to maps__insert() error case
  perf probe: Add ustring support for perf probe command
  perf: Make perf able to build with latest libbfd
  perf test: Fix test case Merge cpu map
  perf parse: Copy string to perf_evsel_config_term
  perf parse: Refactor 'struct perf_evsel_config_term'
  kernel/events: Add a missing prototype for arch_perf_update_userpage()
  perf/cgroups: Install cgroup events to correct cpuctx
  perf/core: Fix mlock accounting in perf_mmap()
2020-02-09 12:04:09 -08:00
Linus Torvalds
2fbc23c738 Two small fixes for the time(r) subsystem:
- Handle a subtle race between the clocksource watchdog and a concurrent
     clocksource watchdog stop/start sequence correctly to prevent a timer
     double add bug.
 
   - Fix the file path for the core time namespace file.
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Merge tag 'timers-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:
 "Two small fixes for the time(r) subsystem:

   - Handle a subtle race between the clocksource watchdog and a
     concurrent clocksource watchdog stop/start sequence correctly to
     prevent a timer double add bug.

   - Fix the file path for the core time namespace file"

* tag 'timers-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: Prevent double add_timer_on() for watchdog_timer
  MAINTAINERS: Correct path to time namespace source file
2020-02-09 12:00:12 -08:00
Linus Torvalds
f06bed87d7 A set of fixes for the interrupt subsystem:
- Provision only ACPI enabled redistributors on GICv3
 
  - Use the proper command colums when building the INVALL command for the
    GICv3-ITS
 
  - Ensure the allocation of the L2 vPE table for GICv4.1
 
  - Correct the GICv4.1 VPROBASER programming so it uses the proper size
 
  - A set of small GICv4.1 tidy up patches
 
  - Configuration cleanup for C-SKY interrupt chip
 
  - Clarify the function documentation for irq_set_wake() to document that
    the wakeup functionality is orthogonal to the irq disable/enable
    mechanism.
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Merge tag 'irq-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull interrupt fixes from Thomas Gleixner:
 "A set of fixes for the interrupt subsystem:

   - Provision only ACPI enabled redistributors on GICv3

   - Use the proper command colums when building the INVALL command for
     the GICv3-ITS

   - Ensure the allocation of the L2 vPE table for GICv4.1

   - Correct the GICv4.1 VPROBASER programming so it uses the proper
     size

   - A set of small GICv4.1 tidy up patches

   - Configuration cleanup for C-SKY interrupt chip

   - Clarify the function documentation for irq_set_wake() to document
     that the wakeup functionality is orthogonal to the irq
     disable/enable mechanism"

* tag 'irq-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3-its: Rename VPENDBASER/VPROPBASER accessors
  irqchip/gic-v3-its: Remove superfluous WARN_ON
  irqchip/gic-v4.1: Drop 'tmp' in inherit_vpe_l1_table_from_rd()
  irqchip/gic-v4.1: Ensure L2 vPE table is allocated at RD level
  irqchip/gic-v4.1: Set vpe_l1_base for all redistributors
  irqchip/gic-v4.1: Fix programming of GICR_VPROPBASER_4_1_SIZE
  genirq: Clarify that irq wake state is orthogonal to enable/disable
  irqchip/gic-v3-its: Reference to its_invall_cmd descriptor when building INVALL
  irqchip: Some Kconfig cleanup for C-SKY
  irqchip/gic-v3: Only provision redistributors that are enabled in ACPI
2020-02-09 11:56:41 -08:00
Linus Torvalds
291abfea47 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Unbalanced locking in mwifiex_process_country_ie, from Brian Norris.

 2) Fix thermal zone registration in iwlwifi, from Andrei
    Otcheretianski.

 3) Fix double free_irq in sgi ioc3 eth, from Thomas Bogendoerfer.

 4) Use after free in mptcp, from Florian Westphal.

 5) Use after free in wireguard's root_remove_peer_lists, from Eric
    Dumazet.

 6) Properly access packets heads in bonding alb code, from Eric
    Dumazet.

 7) Fix data race in skb_queue_len(), from Qian Cai.

 8) Fix regression in r8169 on some chips, from Heiner Kallweit.

 9) Fix XDP program ref counting in hv_netvsc, from Haiyang Zhang.

10) Certain kinds of set link netlink operations can cause a NULL deref
    in the ipv6 addrconf code. Fix from Eric Dumazet.

11) Don't cancel uninitialized work queue in drop monitor, from Ido
    Schimmel.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (84 commits)
  net: thunderx: use proper interface type for RGMII
  mt76: mt7615: fix max_nss in mt7615_eeprom_parse_hw_cap
  bpf: Improve bucket_log calculation logic
  selftests/bpf: Test freeing sockmap/sockhash with a socket in it
  bpf, sockhash: Synchronize_rcu before free'ing map
  bpf, sockmap: Don't sleep while holding RCU lock on tear-down
  bpftool: Don't crash on missing xlated program instructions
  bpf, sockmap: Check update requirements after locking
  drop_monitor: Do not cancel uninitialized work item
  mlxsw: spectrum_dpipe: Add missing error path
  mlxsw: core: Add validation of hardware device types for MGPIR register
  mlxsw: spectrum_router: Clear offload indication from IPv6 nexthops on abort
  selftests: mlxsw: Add test cases for local table route replacement
  mlxsw: spectrum_router: Prevent incorrect replacement of local table routes
  net: dsa: microchip: enable module autoprobe
  ipv6/addrconf: fix potential NULL deref in inet6_set_link_af()
  dpaa_eth: support all modes with rate adapting PHYs
  net: stmmac: update pci platform data to use phy_interface
  net: stmmac: xgmac: fix missing IFF_MULTICAST checki in dwxgmac2_set_filter
  net: stmmac: fix missing IFF_MULTICAST check in dwmac4_set_filter
  ...
2020-02-08 17:15:08 -08:00
Linus Torvalds
c9d35ee049 Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs file system parameter updates from Al Viro:
 "Saner fs_parser.c guts and data structures. The system-wide registry
  of syntax types (string/enum/int32/oct32/.../etc.) is gone and so is
  the horror switch() in fs_parse() that would have to grow another case
  every time something got added to that system-wide registry.

  New syntax types can be added by filesystems easily now, and their
  namespace is that of functions - not of system-wide enum members. IOW,
  they can be shared or kept private and if some turn out to be widely
  useful, we can make them common library helpers, etc., without having
  to do anything whatsoever to fs_parse() itself.

  And we already get that kind of requests - the thing that finally
  pushed me into doing that was "oh, and let's add one for timeouts -
  things like 15s or 2h". If some filesystem really wants that, let them
  do it. Without somebody having to play gatekeeper for the variants
  blessed by direct support in fs_parse(), TYVM.

  Quite a bit of boilerplate is gone. And IMO the data structures make a
  lot more sense now. -200LoC, while we are at it"

* 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (25 commits)
  tmpfs: switch to use of invalfc()
  cgroup1: switch to use of errorfc() et.al.
  procfs: switch to use of invalfc()
  hugetlbfs: switch to use of invalfc()
  cramfs: switch to use of errofc() et.al.
  gfs2: switch to use of errorfc() et.al.
  fuse: switch to use errorfc() et.al.
  ceph: use errorfc() and friends instead of spelling the prefix out
  prefix-handling analogues of errorf() and friends
  turn fs_param_is_... into functions
  fs_parse: handle optional arguments sanely
  fs_parse: fold fs_parameter_desc/fs_parameter_spec
  fs_parser: remove fs_parameter_description name field
  add prefix to fs_context->log
  ceph_parse_param(), ceph_parse_mon_ips(): switch to passing fc_log
  new primitive: __fs_parse()
  switch rbd and libceph to p_log-based primitives
  struct p_log, variants of warnf() et.al. taking that one instead
  teach logfc() to handle prefices, give it saner calling conventions
  get rid of cg_invalf()
  ...
2020-02-08 13:26:41 -08:00
David S. Miller
2696e1146d Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2020-02-07

The following pull-request contains BPF updates for your *net* tree.

We've added 15 non-merge commits during the last 10 day(s) which contain
a total of 12 files changed, 114 insertions(+), 31 deletions(-).

The main changes are:

1) Various BPF sockmap fixes related to RCU handling in the map's tear-
   down code, from Jakub Sitnicki.

2) Fix macro state explosion in BPF sk_storage map when calculating its
   bucket_log on allocation, from Martin KaFai Lau.

3) Fix potential BPF sockmap update race by rechecking socket's established
   state under lock, from Lorenz Bauer.

4) Fix crash in bpftool on missing xlated instructions when kptr_restrict
   sysctl is set, from Toke Høiland-Jørgensen.

5) Fix i40e's XSK wakeup code to return proper error in busy state and
   various misc fixes in xdpsock BPF sample code, from Maciej Fijalkowski.

6) Fix the way modifiers are skipped in BTF in the verifier while walking
   pointers to avoid program rejection, from Alexei Starovoitov.

7) Fix Makefile for runqslower BPF tool to i) rebuild on libbpf changes and
   ii) to fix undefined reference linker errors for older gcc version due to
   order of passed gcc parameters, from Yulia Kartseva and Song Liu.

8) Fix a trampoline_count BPF kselftest warning about missing braces around
   initializer, from Andrii Nakryiko.

9) Fix up redundant "HAVE" prefix from large INSN limit kernel probe in
   bpftool, from Michal Rostecki.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-08 15:01:03 +01:00
Stephen Boyd
f9f21cea31 genirq: Clarify that irq wake state is orthogonal to enable/disable
There's some confusion around if an irq that's disabled with disable_irq()
can still wake the system from sleep states such as "suspend to RAM".

Clarify this in the kernel documentation for irq_set_irq_wake() so that
it's clear that an irq can be disabled and still wake the system if it has
been marked for wakeup.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lkml.kernel.org/r/20200206191521.94559-1-swboyd@chromium.org
2020-02-07 21:37:08 +01:00
Al Viro
58c025f0e8 cgroup1: switch to use of errorfc() et.al.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:43 -05:00
Al Viro
d7167b1499 fs_parse: fold fs_parameter_desc/fs_parameter_spec
The former contains nothing but a pointer to an array of the latter...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:37 -05:00
Eric Sandeen
96cafb9ccb fs_parser: remove fs_parameter_description name field
Unused now.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:36 -05:00
Al Viro
fbc2d1686d get rid of cg_invalf()
pointless alias for invalf()...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-07 14:48:31 -05:00
Paul E. McKenney
1e474b28e7 smp/up: Make smp_call_function_single() match SMP semantics
In CONFIG_SMP=y kernels, smp_call_function_single() returns -ENXIO when
invoked for a non-existent CPU.  In contrast, in CONFIG_SMP=n kernels,
a splat is emitted and smp_call_function_single() otherwise silently
ignores its "cpu" argument, instead pretending that the caller intended
to have something happen on CPU 0.  Given that there is now code that
expects smp_call_function_single() to return an error if a bad CPU was
specified, this difference in semantics needs to be addressed.

Bring the semantics of the CONFIG_SMP=n version of
smp_call_function_single() into alignment with its CONFIG_SMP=y
counterpart.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200205143409.GA7021@paulmck-ThinkPad-P72
2020-02-07 15:34:12 +01:00
Linus Torvalds
d854b2d639 kgdb fixes for 5.6-rc1
One of the simplifications added for 5.6-rc1 has caused build
 regressions on some platforms (it was reported for sparc64).
 This pull request fixes it with a direct revert.
 
 Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
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Merge tag 'kgdb-fixes-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux

Pull kgdb fix from Daniel Thompson:
 "One of the simplifications added for 5.6-rc1 has caused build
  regressions on some platforms (it was reported for sparc64).

  This fixes it with a revert"

* tag 'kgdb-fixes-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
  Revert "kdb: Get rid of confusing diag msg from "rd" if current task has no regs"
2020-02-06 09:05:42 -08:00
Daniel Thompson
fcf2736c82 Revert "kdb: Get rid of confusing diag msg from "rd" if current task has no regs"
This reverts commit bbfceba15f.

When DBG_MAX_REG_NUM is zero then a number of symbols are conditionally
defined. It is therefore not possible to check it using C expressions.

Reported-by: Anatoly Pugachev <matorola@gmail.com>
Acked-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-02-06 11:40:09 +00:00
Linus Torvalds
e310396bb8 Tracing updates:
- Added new "bootconfig".
    Looks for a file appended to initrd to add boot config options.
    This has been discussed thoroughly at Linux Plumbers.
    Very useful for adding kprobes at bootup.
    Only enabled if "bootconfig" is on the real kernel command line.
 
  - Created dynamic event creation.
    Merges common code between creating synthetic events and
      kprobe events.
 
  - Rename perf "ring_buffer" structure to "perf_buffer"
 
  - Rename ftrace "ring_buffer" structure to "trace_buffer"
    Had to rename existing "trace_buffer" to "array_buffer"
 
  - Allow trace_printk() to work withing (some) tracing code.
 
  - Sort of tracing configs to be a little better organized
 
  - Fixed bug where ftrace_graph hash was not being protected properly
 
  - Various other small fixes and clean ups
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Merge tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Added new "bootconfig".

   This looks for a file appended to initrd to add boot config options,
   and has been discussed thoroughly at Linux Plumbers.

   Very useful for adding kprobes at bootup.

   Only enabled if "bootconfig" is on the real kernel command line.

 - Created dynamic event creation.

   Merges common code between creating synthetic events and kprobe
   events.

 - Rename perf "ring_buffer" structure to "perf_buffer"

 - Rename ftrace "ring_buffer" structure to "trace_buffer"

   Had to rename existing "trace_buffer" to "array_buffer"

 - Allow trace_printk() to work withing (some) tracing code.

 - Sort of tracing configs to be a little better organized

 - Fixed bug where ftrace_graph hash was not being protected properly

 - Various other small fixes and clean ups

* tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (88 commits)
  bootconfig: Show the number of nodes on boot message
  tools/bootconfig: Show the number of bootconfig nodes
  bootconfig: Add more parse error messages
  bootconfig: Use bootconfig instead of boot config
  ftrace: Protect ftrace_graph_hash with ftrace_sync
  ftrace: Add comment to why rcu_dereference_sched() is open coded
  tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu
  tracing: Annotate ftrace_graph_hash pointer with __rcu
  bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline
  tracing: Use seq_buf for building dynevent_cmd string
  tracing: Remove useless code in dynevent_arg_pair_add()
  tracing: Remove check_arg() callbacks from dynevent args
  tracing: Consolidate some synth_event_trace code
  tracing: Fix now invalid var_ref_vals assumption in trace action
  tracing: Change trace_boot to use synth_event interface
  tracing: Move tracing selftests to bottom of menu
  tracing: Move mmio tracer config up with the other tracers
  tracing: Move tracing test module configs together
  tracing: Move all function tracing configs together
  tracing: Documentation for in-kernel synthetic event API
  ...
2020-02-06 07:12:11 +00:00
Steven Rostedt (VMware)
54a16ff6f2 ftrace: Protect ftrace_graph_hash with ftrace_sync
As function_graph tracer can run when RCU is not "watching", it can not be
protected by synchronize_rcu() it requires running a task on each CPU before
it can be freed. Calling schedule_on_each_cpu(ftrace_sync) needs to be used.

Link: https://lore.kernel.org/r/20200205131110.GT2935@paulmck-ThinkPad-P72

Cc: stable@vger.kernel.org
Fixes: b9b0c831be ("ftrace: Convert graph filter to use hash tables")
Reported-by: "Paul E. McKenney" <paulmck@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-05 17:16:42 -05:00
Steven Rostedt (VMware)
16052dd5bd ftrace: Add comment to why rcu_dereference_sched() is open coded
Because the function graph tracer can execute in sections where RCU is not
"watching", the rcu_dereference_sched() for the has needs to be open coded.
This is fine because the RCU "flavor" of the ftrace hash is protected by
its own RCU handling (it does its own little synchronization on every CPU
and does not rely on RCU sched).

Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-05 17:15:57 -05:00
Amol Grover
fd0e6852c4 tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu
Fix following instances of sparse error
kernel/trace/ftrace.c:5667:29: error: incompatible types in comparison
kernel/trace/ftrace.c:5813:21: error: incompatible types in comparison
kernel/trace/ftrace.c:5868:36: error: incompatible types in comparison
kernel/trace/ftrace.c:5870:25: error: incompatible types in comparison

Use rcu_dereference_protected to dereference the newly annotated pointer.

Link: http://lkml.kernel.org/r/20200205055701.30195-1-frextrite@gmail.com

Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-05 17:14:37 -05:00
Amol Grover
24a9729f83 tracing: Annotate ftrace_graph_hash pointer with __rcu
Fix following instances of sparse error
kernel/trace/ftrace.c:5664:29: error: incompatible types in comparison
kernel/trace/ftrace.c:5785:21: error: incompatible types in comparison
kernel/trace/ftrace.c:5864:36: error: incompatible types in comparison
kernel/trace/ftrace.c:5866:25: error: incompatible types in comparison

Use rcu_dereference_protected to access the __rcu annotated pointer.

Link: http://lkml.kernel.org/r/20200201072703.17330-1-frextrite@gmail.com

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-05 17:14:26 -05:00
Christoph Hellwig
75467ee48a dma-direct: improve DMA mask overflow reporting
Remove the unset dma_mask case as that won't get into mapping calls
anymore, and also report the other errors unconditonally and with a
slightly improved message.  Remove the now pointless report_addr helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad@darnok.org>
2020-02-05 18:53:41 +01:00
Christoph Hellwig
4a47cbae04 dma-direct: improve swiotlb error reporting
Untangle the way how dma_direct_map_page calls into swiotlb to be able
to properly report errors where the swiotlb DMA address overflows the
mask separately from overflows in the !swiotlb case.  This means that
siotlb_map now has to do a little more work that duplicates
dma_direct_map_page, but doing so greatly simplifies the calling
convention.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2020-02-05 18:53:05 +01:00
Christoph Hellwig
91ef26f914 dma-direct: relax addressability checks in dma_direct_supported
dma_direct_supported tries to find the minimum addressable bitmask
based on the end pfn and optional magic that architectures can use
to communicate the size of the magic ZONE_DMA that can be used
for bounce buffering.  But between the DMA offsets that can change
per device (or sometimes even region), the fact the ZONE_DMA isn't
even guaranteed to be the lowest addresses and failure of having
proper interfaces to the MM code this fails at least for one
arm subarchitecture.

As all the legacy DMA implementations have supported 32-bit DMA
masks, and 32-bit masks are guranteed to always work by the API
contract (using bounce buffers if needed), we can short cut the
complicated check and always return true without breaking existing
assumptions.  Hopefully we can properly clean up the interaction
with the arch defined zones and the bootmem allocator eventually.

Fixes: ad3c7b18c5 ("arm: use swiotlb for bounce buffering on LPAE configs")
Reported-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
2020-02-05 18:50:55 +01:00
Ingo Molnar
fdff7c21ea Merge branch 'linus' into perf/urgent, to synchronize with upstream
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-02-05 08:44:22 +01:00
Linus Torvalds
72f582ff85 Merge branch 'work.recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs recursive removal updates from Al Viro:
 "We have quite a few places where synthetic filesystems do an
  equivalent of 'rm -rf', with varying amounts of code duplication,
  wrong locking, etc. That really ought to be a library helper.

  Only debugfs (and very similar tracefs) are converted here - I have
  more conversions, but they'd never been in -next, so they'll have to
  wait"

* 'work.recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  simple_recursive_removal(): kernel-side rm -rf for ramfs-style filesystems
2020-02-05 05:09:46 +00:00
Masahiro Yamada
cde26a6e17 kallsyms: fix type of kallsyms_token_table[]
kallsyms_token_table[] only contains ASCII characters. It should be
char instead of u8.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
2020-02-05 13:45:37 +09:00
Alexey Dobriyan
97a32539b9 proc: convert everything to "struct proc_ops"
The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in
seq_file.h.

Conversion rule is:

	llseek		=> proc_lseek
	unlocked_ioctl	=> proc_ioctl

	xxx		=> proc_xxx

	delete ".owner = THIS_MODULE" line

[akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c]
[sfr@canb.auug.org.au: fix kernel/sched/psi.c]
  Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-02-04 03:05:26 +00:00
Alexei Starovoitov
257af63d7f bpf: Fix modifier skipping logic
Fix the way modifiers are skipped while walking pointers. Otherwise second
level dereferences of 'const struct foo *' will be rejected by the verifier.

Fixes: 9e15db6613 ("bpf: Implement accurate raw_tp context access via BTF")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200201000314.261392-1-ast@kernel.org
2020-02-04 00:06:07 +01:00
Linus Torvalds
e17ac02b18 kgdb patches for 5.6-rc1
Everything for kgdb this time around is either simplifications or clean
 ups.
 
 In particular Douglas Anderson's modifications to the backtrace machine
 in the *last* dev cycle have enabled Doug to tidy up some MIPS specific
 backtrace code and stop sharing certain data structures across the
 kernel.  Note that The MIPS folks were on Cc: for the MIPS patch and
 reacted positively (but without an explicit Acked-by).
 
 Doug also got rid of the implicit switching between tasks and register
 sets during some but not of kdb's backtrace actions (because the
 implicit switching was either confusing for users, pointless or both).
 
 Finally there is a coverity fix and patch to replace open coded console
 traversal with the proper helper function.
 
 Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
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Merge tag 'kgdb-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux

Pull kgdb updates from Daniel Thompson:
 "Everything for kgdb this time around is either simplifications or
  clean ups.

  In particular Douglas Anderson's modifications to the backtrace
  machine in the *last* dev cycle have enabled Doug to tidy up some MIPS
  specific backtrace code and stop sharing certain data structures
  across the kernel. Note that The MIPS folks were on Cc: for the MIPS
  patch and reacted positively (but without an explicit Acked-by).

  Doug also got rid of the implicit switching between tasks and register
  sets during some but not of kdb's backtrace actions (because the
  implicit switching was either confusing for users, pointless or both).

  Finally there is a coverity fix and patch to replace open coded
  console traversal with the proper helper function"

* tag 'kgdb-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
  kdb: Use for_each_console() helper
  kdb: remove redundant assignment to pointer bp
  kdb: Get rid of confusing diag msg from "rd" if current task has no regs
  kdb: Gid rid of implicit setting of the current task / regs
  kdb: kdb_current_task shouldn't be exported
  kdb: kdb_current_regs should be private
  MIPS: kdb: Remove old workaround for backtracing on other CPUs
2020-02-03 16:59:51 +00:00
Tom Zanussi
2b90927c77 tracing: Use seq_buf for building dynevent_cmd string
The dynevent_cmd commands that build up the command string don't need
to do that themselves - there's a seq_buf facility that does pretty
much the same thing those command are doing manually, so use it
instead.

Link: http://lkml.kernel.org/r/eb8a6e835c964d0ab8a38cbf5ffa60746b54a465.1580506712.git.zanussi@kernel.org

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-01 13:10:15 -05:00
Tom Zanussi
e9260f6257 tracing: Remove useless code in dynevent_arg_pair_add()
The final addition to q is unnecessary, since q isn't ever used
afterwards.

Link: http://lkml.kernel.org/r/7880a1268217886cdba7035526650195668da856.1580506712.git.zanussi@kernel.org

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-01 13:09:42 -05:00
Tom Zanussi
74403b6c50 tracing: Remove check_arg() callbacks from dynevent args
It's kind of strange to have check_arg() callbacks as part of the arg
objects themselves; it makes more sense to just pass these in when the
args are added instead.

Remove the check_arg() callbacks from those objects which also means
removing the check_arg() args from the init functions, adding them to
the add functions and fixing up existing callers.

Link: http://lkml.kernel.org/r/c7708d6f177fcbe1a36b6e4e8e150907df0fa5d2.1580506712.git.zanussi@kernel.org

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-02-01 13:09:23 -05:00
Konstantin Khlebnikov
febac332a8 clocksource: Prevent double add_timer_on() for watchdog_timer
Kernel crashes inside QEMU/KVM are observed:

  kernel BUG at kernel/time/timer.c:1154!
  BUG_ON(timer_pending(timer) || !timer->function) in add_timer_on().

At the same time another cpu got:

  general protection fault: 0000 [#1] SMP PTI of poinson pointer 0xdead000000000200 in:

  __hlist_del at include/linux/list.h:681
  (inlined by) detach_timer at kernel/time/timer.c:818
  (inlined by) expire_timers at kernel/time/timer.c:1355
  (inlined by) __run_timers at kernel/time/timer.c:1686
  (inlined by) run_timer_softirq at kernel/time/timer.c:1699

Unfortunately kernel logs are badly scrambled, stacktraces are lost.

Printing the timer->function before the BUG_ON() pointed to
clocksource_watchdog().

The execution of clocksource_watchdog() can race with a sequence of
clocksource_stop_watchdog() .. clocksource_start_watchdog():

expire_timers()
 detach_timer(timer, true);
  timer->entry.pprev = NULL;
 raw_spin_unlock_irq(&base->lock);
 call_timer_fn
  clocksource_watchdog()

					clocksource_watchdog_kthread() or
					clocksource_unbind()

					spin_lock_irqsave(&watchdog_lock, flags);
					clocksource_stop_watchdog();
					 del_timer(&watchdog_timer);
					 watchdog_running = 0;
					spin_unlock_irqrestore(&watchdog_lock, flags);

					spin_lock_irqsave(&watchdog_lock, flags);
					clocksource_start_watchdog();
					 add_timer_on(&watchdog_timer, ...);
					 watchdog_running = 1;
					spin_unlock_irqrestore(&watchdog_lock, flags);

  spin_lock(&watchdog_lock);
  add_timer_on(&watchdog_timer, ...);
   BUG_ON(timer_pending(timer) || !timer->function);
    timer_pending() -> true
    BUG()

I.e. inside clocksource_watchdog() watchdog_timer could be already armed.

Check timer_pending() before calling add_timer_on(). This is sufficient as
all operations are synchronized by watchdog_lock.

Fixes: 75c5158f70 ("timekeeping: Update clocksource with stop_machine")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/158048693917.4378.13823603769948933793.stgit@buzz
2020-02-01 11:07:56 +01:00
Thomas Gleixner
6f1a4891a5 x86/apic/msi: Plug non-maskable MSI affinity race
Evan tracked down a subtle race between the update of the MSI message and
the device raising an interrupt internally on PCI devices which do not
support MSI masking. The update of the MSI message is non-atomic and
consists of either 2 or 3 sequential 32bit wide writes to the PCI config
space.

   - Write address low 32bits
   - Write address high 32bits (If supported by device)
   - Write data

When an interrupt is migrated then both address and data might change, so
the kernel attempts to mask the MSI interrupt first. But for MSI masking is
optional, so there exist devices which do not provide it. That means that
if the device raises an interrupt internally between the writes then a MSI
message is sent built from half updated state.

On x86 this can lead to spurious interrupts on the wrong interrupt
vector when the affinity setting changes both address and data. As a
consequence the device interrupt can be lost causing the device to
become stuck or malfunctioning.

Evan tried to handle that by disabling MSI accross an MSI message
update. That's not feasible because disabling MSI has issues on its own:

 If MSI is disabled the PCI device is routing an interrupt to the legacy
 INTx mechanism. The INTx delivery can be disabled, but the disablement is
 not working on all devices.

 Some devices lose interrupts when both MSI and INTx delivery are disabled.

Another way to solve this would be to enforce the allocation of the same
vector on all CPUs in the system for this kind of screwed devices. That
could be done, but it would bring back the vector space exhaustion problems
which got solved a few years ago.

Fortunately the high address (if supported by the device) is only relevant
when X2APIC is enabled which implies interrupt remapping. In the interrupt
remapping case the affinity setting is happening at the interrupt remapping
unit and the PCI MSI message is programmed only once when the PCI device is
initialized.

That makes it possible to solve it with a two step update:

  1) Target the MSI msg to the new vector on the current target CPU

  2) Target the MSI msg to the new vector on the new target CPU

In both cases writing the MSI message is only changing a single 32bit word
which prevents the issue of inconsistency.

After writing the final destination it is necessary to check whether the
device issued an interrupt while the intermediate state #1 (new vector,
current CPU) was in effect.

This is possible because the affinity change is always happening on the
current target CPU. The code runs with interrupts disabled, so the
interrupt can be detected by checking the IRR of the local APIC. If the
vector is pending in the IRR then the interrupt is retriggered on the new
target CPU by sending an IPI for the associated vector on the target CPU.

This can cause spurious interrupts on both the local and the new target
CPU.

 1) If the new vector is not in use on the local CPU and the device
    affected by the affinity change raised an interrupt during the
    transitional state (step #1 above) then interrupt entry code will
    ignore that spurious interrupt. The vector is marked so that the
    'No irq handler for vector' warning is supressed once.

 2) If the new vector is in use already on the local CPU then the IRR check
    might see an pending interrupt from the device which is using this
    vector. The IPI to the new target CPU will then invoke the handler of
    the device, which got the affinity change, even if that device did not
    issue an interrupt

 3) If the new vector is in use already on the local CPU and the device
    affected by the affinity change raised an interrupt during the
    transitional state (step #1 above) then the handler of the device which
    uses that vector on the local CPU will be invoked.

expose issues in device driver interrupt handlers which are not prepared to
handle a spurious interrupt correctly. This not a regression, it's just
exposing something which was already broken as spurious interrupts can
happen for a lot of reasons and all driver handlers need to be able to deal
with them.

Reported-by: Evan Green <evgreen@chromium.org>
Debugged-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Evan Green <evgreen@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87imkr4s7n.fsf@nanos.tec.linutronix.de
2020-02-01 09:31:47 +01:00
Tom Zanussi
249d7b2ef6 tracing: Consolidate some synth_event_trace code
The synth_event trace code contains some almost identical functions
and some small functions that are called only once - consolidate the
common code into single functions and fold in the small functions to
simplify the code overall.

Link: http://lkml.kernel.org/r/d1c8d8ad124a653b7543afe801d38c199ca5c20e.1580506712.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-31 18:35:17 -05:00
Linus Torvalds
7eec11d3a7 Merge branch 'akpm' (patches from Andrew)
Pull updates from Andrew Morton:
 "Most of -mm and quite a number of other subsystems: hotfixes, scripts,
  ocfs2, misc, lib, binfmt, init, reiserfs, exec, dma-mapping, kcov.

  MM is fairly quiet this time.  Holidays, I assume"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits)
  kcov: ignore fault-inject and stacktrace
  include/linux/io-mapping.h-mapping: use PHYS_PFN() macro in io_mapping_map_atomic_wc()
  execve: warn if process starts with executable stack
  reiserfs: prevent NULL pointer dereference in reiserfs_insert_item()
  init/main.c: fix misleading "This architecture does not have kernel memory protection" message
  init/main.c: fix quoted value handling in unknown_bootoption
  init/main.c: remove unnecessary repair_env_string in do_initcall_level
  init/main.c: log arguments and environment passed to init
  fs/binfmt_elf.c: coredump: allow process with empty address space to coredump
  fs/binfmt_elf.c: coredump: delete duplicated overflow check
  fs/binfmt_elf.c: coredump: allocate core ELF header on stack
  fs/binfmt_elf.c: make BAD_ADDR() unlikely
  fs/binfmt_elf.c: better codegen around current->mm
  fs/binfmt_elf.c: don't copy ELF header around
  fs/binfmt_elf.c: fix ->start_code calculation
  fs/binfmt_elf.c: smaller code generation around auxv vector fill
  lib/find_bit.c: uninline helper _find_next_bit()
  lib/find_bit.c: join _find_next_bit{_le}
  uapi: rename ext2_swab() to swab() and share globally in swab.h
  lib/scatterlist.c: adjust indentation in __sg_alloc_table
  ...
2020-01-31 12:16:36 -08:00
Linus Torvalds
ddaefe8947 Modules updates for v5.6
Summary of modules changes for the 5.6 merge window:
 
 - Add "MS" (SHF_MERGE|SHF_STRINGS) section flags to __ksymtab_strings to
   indicate to the linker that it can perform string deduplication (i.e.,
   duplicate strings are reduced to a single copy in the string table).
   This means any repeated namespace string would be merged to just one
   entry in __ksymtab_strings.
 
 - Various code cleanups and small fixes (fix small memleak in error path,
   improve moduleparam docs, silence rcu warnings, improve error logging)
 
 Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull module updates from Jessica Yu:
 "Summary of modules changes for the 5.6 merge window:

   - Add "MS" (SHF_MERGE|SHF_STRINGS) section flags to __ksymtab_strings
     to indicate to the linker that it can perform string deduplication
     (i.e., duplicate strings are reduced to a single copy in the string
     table). This means any repeated namespace string would be merged to
     just one entry in __ksymtab_strings.

   - Various code cleanups and small fixes (fix small memleak in error
     path, improve moduleparam docs, silence rcu warnings, improve error
     logging)"

* tag 'modules-for-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module.h: Annotate mod_kallsyms with __rcu
  module: avoid setting info->name early in case we can fall back to info->mod->name
  modsign: print module name along with error message
  kernel/module: Fix memleak in module_add_modinfo_attrs()
  export.h: reduce __ksymtab_strings string duplication by using "MS" section flags
  moduleparam: fix kerneldoc
  modules: lockdep: Suppress suspicious RCU usage warning
2020-01-31 11:42:13 -08:00
Dmitry Vyukov
43e76af85f kcov: ignore fault-inject and stacktrace
Don't instrument 3 more files that contain debugging facilities and
produce large amounts of uninteresting coverage for every syscall.

The following snippets are sprinkled all over the place in kcov traces
in a debugging kernel.  We already try to disable instrumentation of
stack unwinding code and of most debug facilities.  I guess we did not
use fault-inject.c at the time, and stacktrace.c was somehow missed (or
something has changed in kernel/configs).  This change both speeds up
kcov (kernel doesn't need to store these PCs, user-space doesn't need to
process them) and frees trace buffer capacity for more useful coverage.

  should_fail
  lib/fault-inject.c:149
  fail_dump
  lib/fault-inject.c:45

  stack_trace_save
  kernel/stacktrace.c:124
  stack_trace_consume_entry
  kernel/stacktrace.c:86
  stack_trace_consume_entry
  kernel/stacktrace.c:89
  ... a hundred frames skipped ...
  stack_trace_consume_entry
  kernel/stacktrace.c:93
  stack_trace_consume_entry
  kernel/stacktrace.c:86

Link: http://lkml.kernel.org/r/20200116111449.217744-1-dvyukov@gmail.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-31 10:30:41 -08:00
Tom Zanussi
d380dcde9a tracing: Fix now invalid var_ref_vals assumption in trace action
The patch 'tracing: Fix histogram code when expression has same var as
value' added code to return an existing variable reference when
creating a new variable reference, which resulted in var_ref_vals
slots being reused instead of being duplicated.

The implementation of the trace action assumes that the end of the
var_ref_vals array starting at action_data.var_ref_idx corresponds to
the values that will be assigned to the trace params. The patch
mentioned above invalidates that assumption, which means that each
param needs to explicitly specify its index into var_ref_vals.

This fix changes action_data.var_ref_idx to an array of var ref
indexes to account for that.

Link: https://lore.kernel.org/r/1580335695.6220.8.camel@kernel.org

Fixes: 8bcebc77e8 ("tracing: Fix histogram code when expression has same var as value")
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-31 12:59:26 -05:00
Tom Zanussi
fdeb1aca28 tracing: Change trace_boot to use synth_event interface
Have trace_boot_add_synth_event() use the synth_event interface.

Also, rename synth_event_run_cmd() to synth_event_run_command() now
that trace_boot's version is gone.

Link: http://lkml.kernel.org/r/94f1fa0e31846d0bddca916b8663404b20559e34.1580323897.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-31 12:59:26 -05:00
Andy Shevchenko
dc2c733e65 kdb: Use for_each_console() helper
Replace open coded single-linked list iteration loop with for_each_console()
helper in use.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-01-31 17:34:54 +00:00
Colin Ian King
a4f8a7fb19 kdb: remove redundant assignment to pointer bp
The point bp is assigned a value that is never read, it is being
re-assigned later to bp = &kdb_breakpoints[lowbp] in a for-loop.
Remove the redundant assignment.

Addresses-Coverity ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20191128130753.181246-1-colin.king@canonical.com
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-01-31 17:34:06 +00:00
Douglas Anderson
bbfceba15f kdb: Get rid of confusing diag msg from "rd" if current task has no regs
If you switch to a sleeping task with the "pid" command and then type
"rd", kdb tells you this:

  No current kdb registers.  You may need to select another task
  diag: -17: Invalid register name

The first message makes sense, but not the second.  Fix it by just
returning 0 after commands accessing the current registers finish if
we've already printed the "No current kdb registers" error.

While fixing kdb_rd(), change the function to use "if" rather than
"ifdef".  It cleans the function up a bit and any modern compiler will
have no trouble handling still producing good code.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20191109111624.5.I121f4c6f0c19266200bf6ef003de78841e5bfc3d@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-01-31 17:34:03 +00:00
Douglas Anderson
9441d5f6b7 kdb: Gid rid of implicit setting of the current task / regs
Some (but not all?) of the kdb backtrace paths would cause the
kdb_current_task and kdb_current_regs to remain changed.  As discussed
in a review of a previous patch [1], this doesn't seem intuitive, so
let's fix that.

...but, it turns out that there's actually no longer any reason to set
the current task / current regs while backtracing anymore anyway.  As
of commit 2277b49258 ("kdb: Fix stack crawling on 'running' CPUs
that aren't the master") if we're backtracing on a task running on a
CPU we ask that CPU to do the backtrace itself.  Linux can do that
without anything fancy.  If we're doing backtrace on a sleeping task
we can also do that fine without updating globals.  So this patch
mostly just turns into deleting a bunch of code.

[1] https://lore.kernel.org/r/20191010150735.dhrj3pbjgmjrdpwr@holly.lan

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20191109111624.4.Ibc3d982bbeb9e46872d43973ba808cd4c79537c7@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-01-31 17:34:00 +00:00
Douglas Anderson
a8649fb0a8 kdb: kdb_current_task shouldn't be exported
The kdb_current_task variable has been declared in
"kernel/debug/kdb/kdb_private.h" since 2010 when kdb was added to the
mainline kernel.  This is not a public header.  There should be no
reason that kdb_current_task should be exported and there are no
in-kernel users that need it.  Remove the export.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20191109111623.3.I14b22b5eb15ca8f3812ab33e96621231304dc1f7@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-01-31 17:33:57 +00:00
Douglas Anderson
c67c10a67f kdb: kdb_current_regs should be private
As of the patch ("MIPS: kdb: Remove old workaround for backtracing on
other CPUs") there is no reason for kdb_current_regs to be in the
public "kdb.h".  Let's move it next to kdb_current_task.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20191109111623.2.Iadbfb484e90b557cc4b5ac9890bfca732cd99d77@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
2020-01-31 17:33:54 +00:00
Tejun Heo
0cd9d33ace cgroup: init_tasks shouldn't be linked to the root cgroup
5153faac18 ("cgroup: remove cgroup_enable_task_cg_lists()
optimization") removed lazy initialization of css_sets so that new
tasks are always lniked to its css_set. In the process, it incorrectly
ended up adding init_tasks to root css_set. They show up as PID 0's in
root's cgroup.procs triggering warnings in systemd and generally
confusing people.

Fix it by skip css_set linking for init_tasks.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: https://github.com/joanbm
Link: https://github.com/systemd/systemd/issues/14682
Fixes: 5153faac18 ("cgroup: remove cgroup_enable_task_cg_lists() optimization")
Cc: stable@vger.kernel.org # v5.5+
2020-01-30 11:37:33 -05:00
Steven Rostedt (VMware)
1e837945a8 tracing: Move tracing selftests to bottom of menu
Move all the tracing selftest configs to the bottom of the tracing menu.
There's no reason for them to be interspersed throughout.

Also, move the bootconfig menu to the top.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:29 -05:00
Steven Rostedt (VMware)
21b3ce3063 tracing: Move mmio tracer config up with the other tracers
Move the config that enables the mmiotracer with the other tracers such that
all the tracers are together.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:29 -05:00
Steven Rostedt (VMware)
a48fc4f5f1 tracing: Move tracing test module configs together
The MMIO test module was by itself, move it to the other test modules. Also,
add the text "Test module" to PREEMPTIRQ_DELAY_TEST as that create a test
module as well.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:29 -05:00
Steven Rostedt (VMware)
61778cd70c tracing: Move all function tracing configs together
The features that depend on the function tracer were spread out through the
tracing menu, pull them together as it is easier to manage.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:29 -05:00
Tom Zanussi
64836248dd tracing: Add kprobe event command generation test module
Add a test module that checks the basic functionality of the in-kernel
kprobe event command generation API by creating kprobe events from a
module.

Link: http://lkml.kernel.org/r/97e502b204f9dba948e3fa3a4315448298218787.1580323897.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:28 -05:00
Tom Zanussi
29a1548105 tracing: Change trace_boot to use kprobe_event interface
Have trace_boot_add_kprobe_event() use the kprobe_event interface.

Also, rename kprobe_event_run_cmd() to kprobe_event_run_command() now
that trace_boot's version is gone.

Link: http://lkml.kernel.org/r/af5429d11291ab1e9a85a0ff944af3b2bcf193c7.1580323897.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:28 -05:00
Tom Zanussi
2a588dd1d5 tracing: Add kprobe event command generation functions
Add functions used to generate kprobe event commands, built on top of
the dynevent_cmd interface.

kprobe_event_gen_cmd_start() is used to create a kprobe event command
using a variable arg list, and kretprobe_event_gen_cmd_start() does
the same for kretprobe event commands.  kprobe_event_add_fields() can
be used to add single fields one by one or as a group.  Once all
desired fields are added, kprobe_event_gen_cmd_end() or
kretprobe_event_gen_cmd_end() respectively are used to actually
execute the command and create the event.

Link: http://lkml.kernel.org/r/95cc4696502bb6017f9126f306a45ad19b4cc14f.1580323897.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:28 -05:00
Tom Zanussi
9fe41efaca tracing: Add synth event generation test module
Add a test module that checks the basic functionality of the in-kernel
synthetic event generation API by generating and tracing synthetic
events from a module.

Link: http://lkml.kernel.org/r/fcb4dd9eb9eefb70ab20538d3529d51642389664.1580323897.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:28 -05:00
Tom Zanussi
8dcc53ad95 tracing: Add synth_event_trace() and related functions
Add an exported function named synth_event_trace(), allowing modules
or other kernel code to trace synthetic events.

Also added are several functions that allow the same functionality to
be broken out in a piecewise fashion, which are useful in situations
where tracing an event from a full array of values would be
cumbersome.  Those functions are synth_event_trace_start/end() and
synth_event_add_(next)_val().

Link: http://lkml.kernel.org/r/7a84de5f1854acf4144b57efe835ca645afa764f.1580323897.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:28 -05:00
Tom Zanussi
35ca5207c2 tracing: Add synthetic event command generation functions
Add functions used to generate synthetic event commands, built on top
of the dynevent_cmd interface.

synth_event_gen_cmd_start() is used to create a synthetic event
command using a variable arg list and
synth_event_gen_cmd_array_start() does the same thing but using an
array of field descriptors.  synth_event_add_field(),
synth_event_add_field_str() and synth_event_add_fields() can be used
to add single fields one by one or as a group.  Once all desired
fields are added, synth_event_gen_cmd_end() is used to actually
execute the command and create the event.

synth_event_create() does everything, including creating the event, in
a single call.

Link: http://lkml.kernel.org/r/38fef702fad5ef208009f459552f34a94befd860.1580323897.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:28 -05:00
Tom Zanussi
86c5426bad tracing: Add dynamic event command creation interface
Add an interface used to build up dynamic event creation commands,
such as synthetic and kprobe events.  Interfaces specific to those
particular types of events and others can be built on top of this
interface.

Command creation is started by first using the dynevent_cmd_init()
function to initialize the dynevent_cmd object.  Following that, args
are appended and optionally checked by the dynevent_arg_add() and
dynevent_arg_pair_add() functions, which use objects representing
arguments and pairs of arguments, initialized respectively by
dynevent_arg_init() and dynevent_arg_pair_init().  Finally, once all
args have been successfully added, the command is finalized and
actually created using dynevent_create().

The code here for actually printing into the dyn_event->cmd buffer
using snprintf() etc was adapted from v4 of Masami's 'tracing/boot:
Add synthetic event support' patch.

Link: http://lkml.kernel.org/r/1f65fa44390b6f238f6036777c3784ced1dcc6a0.1580323897.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:28 -05:00
Tom Zanussi
f5f6b255a2 tracing: Add synth_event_delete()
create_or_delete_synth_event() contains code to delete a synthetic
event, which would be useful on its own - specifically, it would be
useful to allow event-creating modules to call it separately.

Separate out the delete code from that function and create an exported
function named synth_event_delete().

Link: http://lkml.kernel.org/r/050db3b06df7f0a4b8a2922da602d1d879c7c1c2.1580323897.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:28 -05:00
Tom Zanussi
e3e2a2cc9c tracing: Add trace_get/put_event_file()
Add a function to get an event file and prevent it from going away on
module or instance removal.

trace_get_event_file() will find an event file in a given instance (if
instance is NULL, it assumes the top trace array) and return it,
pinning the instance's trace array as well as the event's module, if
applicable, so they won't go away while in use.

trace_put_event_file() does the matching release.

Link: http://lkml.kernel.org/r/bb31ac4bdda168d5ed3c4b5f5a4c8f633e8d9118.1580323897.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
[ Moved trace_array_put() to end of trace_put_event_file() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:28 -05:00
Tom Zanussi
89c95fcef1 tracing: Add trace_array_find/_get() to find instance trace arrays
Add a new trace_array_find() function that can be used to find a trace
array given the instance name, and replace existing code that does the
same thing with it.  Also add trace_array_find_get() which does the
same but returns the trace array after upping its refcount.

Also make both available for use outside of trace.c.

Link: http://lkml.kernel.org/r/cb68528c975eba95bee4561ac67dd1499423b2e5.1580323897.git.zanussi@kernel.org

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:27 -05:00
Vasily Averin
6722b23e7a trigger_next should increase position index
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

Without patch:
 # dd bs=30 skip=1 if=/sys/kernel/tracing/events/sched/sched_switch/trigger
 dd: /sys/kernel/tracing/events/sched/sched_switch/trigger: cannot skip to specified offset
 n traceoff snapshot stacktrace enable_event disable_event enable_hist disable_hist hist
 # Available triggers:
 # traceon traceoff snapshot stacktrace enable_event disable_event enable_hist disable_hist hist
 6+1 records in
 6+1 records out
 206 bytes copied, 0.00027916 s, 738 kB/s

Notice the printing of "# Available triggers:..." after the line.

With the patch:
 # dd bs=30 skip=1 if=/sys/kernel/tracing/events/sched/sched_switch/trigger
 dd: /sys/kernel/tracing/events/sched/sched_switch/trigger: cannot skip to specified offset
 n traceoff snapshot stacktrace enable_event disable_event enable_hist disable_hist hist
 2+1 records in
 2+1 records out
 88 bytes copied, 0.000526867 s, 167 kB/s

It only prints the end of the file, and does not restart.

Link: http://lkml.kernel.org/r/3c35ee24-dd3a-8119-9c19-552ed253388a@virtuozzo.com

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:27 -05:00
Vasily Averin
039958a5f7 tracing: eval_map_next() should always increase position index
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

Link: http://lkml.kernel.org/r/7ad85b22-1866-977c-db17-88ac438bc764@virtuozzo.com

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
[ This is not a bug fix, it just makes it "technically correct"
  which is why I applied it. NULL is only returned on an anomaly
  which triggers a WARN_ON ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:27 -05:00
Vasily Averin
e4075e8bdf ftrace: fpid_next() should increase position index
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

Without patch:
 # dd bs=4 skip=1 if=/sys/kernel/tracing/set_ftrace_pid
 dd: /sys/kernel/tracing/set_ftrace_pid: cannot skip to specified offset
 id
 no pid
 2+1 records in
 2+1 records out
 10 bytes copied, 0.000213285 s, 46.9 kB/s

Notice the "id" followed by "no pid".

With the patch:
 # dd bs=4 skip=1 if=/sys/kernel/tracing/set_ftrace_pid
 dd: /sys/kernel/tracing/set_ftrace_pid: cannot skip to specified offset
 id
 0+1 records in
 0+1 records out
 3 bytes copied, 0.000202112 s, 14.8 kB/s

Notice that it only prints "id" and not the "no pid" afterward.

Link: http://lkml.kernel.org/r/4f87c6ad-f114-30bb-8506-c32274ce2992@virtuozzo.com

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:27 -05:00
Mathieu Desnoyers
64ae572bc7 tracing: Fix sched switch start/stop refcount racy updates
Reading the sched_cmdline_ref and sched_tgid_ref initial state within
tracing_start_sched_switch without holding the sched_register_mutex is
racy against concurrent updates, which can lead to tracepoint probes
being registered more than once (and thus trigger warnings within
tracepoint.c).

[ May be the fix for this bug ]
Link: https://lore.kernel.org/r/000000000000ab6f84056c786b93@google.com

Link: http://lkml.kernel.org/r/20190817141208.15226-1-mathieu.desnoyers@efficios.com

Cc: stable@vger.kernel.org
CC: Steven Rostedt (VMware) <rostedt@goodmis.org>
CC: Joel Fernandes (Google) <joel@joelfernandes.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Paul E. McKenney <paulmck@linux.ibm.com>
Reported-by: syzbot+774fddf07b7ab29a1e55@syzkaller.appspotmail.com
Fixes: d914ba37d7 ("tracing: Add support for recording tgid of tasks")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-30 09:46:10 -05:00
Nicolas Saenz Julienne
8c8c5a4994 dma-contiguous: CMA: give precedence to cmdline
Although the device tree might contain a reserved-memory DT node
dedicated as the default CMA pool, users might want to change CMA's
parameters using the kernel command line for debugging purposes and
whatnot. Honor this by bypassing the reserved memory CMA setup, which
will ultimately end up freeing the memblock and allow the command line
CMA configuration routine to run.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Phil Elwell <phil@raspberrypi.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-01-30 14:41:42 +01:00
Linus Torvalds
39bed42de2 hmm related patches for 5.6
This small series revises the names in mmu_notifier to make the code
 clearer and more readable.
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Pull mmu_notifier updates from Jason Gunthorpe:
 "This small series revises the names in mmu_notifier to make the code
  clearer and more readable"

* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  mm/mmu_notifiers: Use 'interval_sub' as the variable for mmu_interval_notifier
  mm/mmu_notifiers: Use 'subscription' as the variable name for mmu_notifier
  mm/mmu_notifier: Rename struct mmu_notifier_mm to mmu_notifier_subscriptions
2020-01-29 19:56:50 -08:00
Linus Torvalds
83fa805bcb threads-v5.6
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Merge tag 'threads-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull thread management updates from Christian Brauner:
 "Sargun Dhillon over the last cycle has worked on the pidfd_getfd()
  syscall.

  This syscall allows for the retrieval of file descriptors of a process
  based on its pidfd. A task needs to have ptrace_may_access()
  permissions with PTRACE_MODE_ATTACH_REALCREDS (suggested by Oleg and
  Andy) on the target.

  One of the main use-cases is in combination with seccomp's user
  notification feature. As a reminder, seccomp's user notification
  feature was made available in v5.0. It allows a task to retrieve a
  file descriptor for its seccomp filter. The file descriptor is usually
  handed of to a more privileged supervising process. The supervisor can
  then listen for syscall events caught by the seccomp filter of the
  supervisee and perform actions in lieu of the supervisee, usually
  emulating syscalls. pidfd_getfd() is needed to expand its uses.

  There are currently two major users that wait on pidfd_getfd() and one
  future user:

   - Netflix, Sargun said, is working on a service mesh where users
     should be able to connect to a dns-based VIP. When a user connects
     to e.g. 1.2.3.4:80 that runs e.g. service "foo" they will be
     redirected to an envoy process. This service mesh uses seccomp user
     notifications and pidfd to intercept all connect calls and instead
     of connecting them to 1.2.3.4:80 connects them to e.g.
     127.0.0.1:8080.

   - LXD uses the seccomp notifier heavily to intercept and emulate
     mknod() and mount() syscalls for unprivileged containers/processes.
     With pidfd_getfd() more uses-cases e.g. bridging socket connections
     will be possible.

   - The patchset has also seen some interest from the browser corner.
     Right now, Firefox is using a SECCOMP_RET_TRAP sandbox managed by a
     broker process. In the future glibc will start blocking all signals
     during dlopen() rendering this type of sandbox impossible. Hence,
     in the future Firefox will switch to a seccomp-user-nofication
     based sandbox which also makes use of file descriptor retrieval.
     The thread for this can be found at
     https://sourceware.org/ml/libc-alpha/2019-12/msg00079.html

  With pidfd_getfd() it is e.g. possible to bridge socket connections
  for the supervisee (binding to a privileged port) and taking actions
  on file descriptors on behalf of the supervisee in general.

  Sargun's first version was using an ioctl on pidfds but various people
  pushed for it to be a proper syscall which he duely implemented as
  well over various review cycles. Selftests are of course included.
  I've also added instructions how to deal with merge conflicts below.

  There's also a small fix coming from the kernel mentee project to
  correctly annotate struct sighand_struct with __rcu to fix various
  sparse warnings. We've received a few more such fixes and even though
  they are mostly trivial I've decided to postpone them until after -rc1
  since they came in rather late and I don't want to risk introducing
  build warnings.

  Finally, there's a new prctl() command PR_{G,S}ET_IO_FLUSHER which is
  needed to avoid allocation recursions triggerable by storage drivers
  that have userspace parts that run in the IO path (e.g. dm-multipath,
  iscsi, etc). These allocation recursions deadlock the device.

  The new prctl() allows such privileged userspace components to avoid
  allocation recursions by setting the PF_MEMALLOC_NOIO and
  PF_LESS_THROTTLE flags. The patch carries the necessary acks from the
  relevant maintainers and is routed here as part of prctl()
  thread-management."

* tag 'threads-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  prctl: PR_{G,S}ET_IO_FLUSHER to support controlling memory reclaim
  sched.h: Annotate sighand_struct with __rcu
  test: Add test for pidfd getfd
  arch: wire up pidfd_getfd syscall
  pid: Implement pidfd_getfd syscall
  vfs, fdtable: Add fget_task helper
2020-01-29 19:38:34 -08:00
Linus Torvalds
08a3ef8f6b linux-kselftest-5.6-rc1-kunit
This kunit update for Linux 5.6-rc1 consists of:
 
 -- Support for building kunit as a module from Alan Maguire
 -- AppArmor KUnit tests for policy unpack from Mike Salvatore
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Merge tag 'linux-kselftest-5.6-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kselftest kunit updates from Shuah Khan:
 "This kunit update consists of:

   - Support for building kunit as a module from Alan Maguire

   - AppArmor KUnit tests for policy unpack from Mike Salvatore"

* tag 'linux-kselftest-5.6-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  kunit: building kunit as a module breaks allmodconfig
  kunit: update documentation to describe module-based build
  kunit: allow kunit to be loaded as a module
  kunit: remove timeout dependence on sysctl_hung_task_timeout_seconds
  kunit: allow kunit tests to be loaded as a module
  kunit: hide unexported try-catch interface in try-catch-impl.h
  kunit: move string-stream.h to lib/kunit
  apparmor: add AppArmor KUnit tests for policy unpack
2020-01-29 15:25:34 -08:00
Linus Torvalds
22b17db4ea y2038: core, driver and file system changes
These are updates to device drivers and file systems that for some reason
 or another were not included in the kernel in the previous y2038 series.
 
 I've gone through all users of time_t again to make sure the kernel is
 in a long-term maintainable state, replacing all remaining references
 to time_t with safe alternatives.
 
 Some related parts of the series were picked up into the nfsd, xfs,
 alsa and v4l2 trees. A final set of patches in linux-mm removes the now
 unused time_t/timeval/timespec types and helper functions after all five
 branches are merged for linux-5.6, ensuring that no new users get merged.
 
 As a result, linux-5.6, or my backport of the patches to 5.4 [1], should
 be the first release that can serve as a base for a 32-bit system designed
 to run beyond year 2038, with a few remaining caveats:
 
 - All user space must be compiled with a 64-bit time_t, which will be
   supported in the coming musl-1.2 and glibc-2.32 releases, along with
   installed kernel headers from linux-5.6 or higher.
 
 - Applications that use the system call interfaces directly need to be
   ported to use the time64 syscalls added in linux-5.1 in place of the
   existing system calls. This impacts most users of futex() and seccomp()
   as well as programming languages that have their own runtime environment
   not based on libc.
 
 - Applications that use a private copy of kernel uapi header files or
   their contents may need to update to the linux-5.6 version, in
   particular for sound/asound.h, xfs/xfs_fs.h, linux/input.h,
   linux/elfcore.h, linux/sockios.h, linux/timex.h and linux/can/bcm.h.
 
 - A few remaining interfaces cannot be changed to pass a 64-bit time_t
   in a compatible way, so they must be configured to use CLOCK_MONOTONIC
   times or (with a y2106 problem) unsigned 32-bit timestamps. Most
   importantly this impacts all users of 'struct input_event'.
 
 - All y2038 problems that are present on 64-bit machines also apply to
   32-bit machines. In particular this affects file systems with on-disk
   timestamps using signed 32-bit seconds: ext4 with ext3-style small
   inodes, ext2, xfs (to be fixed soon) and ufs.
 
 Changes since v1 [2]:
 
 - Add Acks I received
 - Rebase to v5.5-rc1, dropping patches that got merged already
 - Add NFS, XFS and the final three patches from another series
 - Rewrite etnaviv patches
 - Add one late revert to avoid an etnaviv regression
 
 [1] https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=y2038-endgame
 [2] https://lore.kernel.org/lkml/20191108213257.3097633-1-arnd@arndb.de/
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Merge tag 'y2038-drivers-for-v5.6-signed' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

Pull y2038 updates from Arnd Bergmann:
 "Core, driver and file system changes

  These are updates to device drivers and file systems that for some
  reason or another were not included in the kernel in the previous
  y2038 series.

  I've gone through all users of time_t again to make sure the kernel is
  in a long-term maintainable state, replacing all remaining references
  to time_t with safe alternatives.

  Some related parts of the series were picked up into the nfsd, xfs,
  alsa and v4l2 trees. A final set of patches in linux-mm removes the
  now unused time_t/timeval/timespec types and helper functions after
  all five branches are merged for linux-5.6, ensuring that no new users
  get merged.

  As a result, linux-5.6, or my backport of the patches to 5.4 [1],
  should be the first release that can serve as a base for a 32-bit
  system designed to run beyond year 2038, with a few remaining caveats:

   - All user space must be compiled with a 64-bit time_t, which will be
     supported in the coming musl-1.2 and glibc-2.32 releases, along
     with installed kernel headers from linux-5.6 or higher.

   - Applications that use the system call interfaces directly need to
     be ported to use the time64 syscalls added in linux-5.1 in place of
     the existing system calls. This impacts most users of futex() and
     seccomp() as well as programming languages that have their own
     runtime environment not based on libc.

   - Applications that use a private copy of kernel uapi header files or
     their contents may need to update to the linux-5.6 version, in
     particular for sound/asound.h, xfs/xfs_fs.h, linux/input.h,
     linux/elfcore.h, linux/sockios.h, linux/timex.h and
     linux/can/bcm.h.

   - A few remaining interfaces cannot be changed to pass a 64-bit
     time_t in a compatible way, so they must be configured to use
     CLOCK_MONOTONIC times or (with a y2106 problem) unsigned 32-bit
     timestamps. Most importantly this impacts all users of 'struct
     input_event'.

   - All y2038 problems that are present on 64-bit machines also apply
     to 32-bit machines. In particular this affects file systems with
     on-disk timestamps using signed 32-bit seconds: ext4 with
     ext3-style small inodes, ext2, xfs (to be fixed soon) and ufs"

[1] https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=y2038-endgame

* tag 'y2038-drivers-for-v5.6-signed' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (21 commits)
  Revert "drm/etnaviv: reject timeouts with tv_nsec >= NSEC_PER_SEC"
  y2038: sh: remove timeval/timespec usage from headers
  y2038: sparc: remove use of struct timex
  y2038: rename itimerval to __kernel_old_itimerval
  y2038: remove obsolete jiffies conversion functions
  nfs: fscache: use timespec64 in inode auxdata
  nfs: fix timstamp debug prints
  nfs: use time64_t internally
  sunrpc: convert to time64_t for expiry
  drm/etnaviv: avoid deprecated timespec
  drm/etnaviv: reject timeouts with tv_nsec >= NSEC_PER_SEC
  drm/msm: avoid using 'timespec'
  hfs/hfsplus: use 64-bit inode timestamps
  hostfs: pass 64-bit timestamps to/from user space
  packet: clarify timestamp overflow
  tsacct: add 64-bit btime field
  acct: stop using get_seconds()
  um: ubd: use 64-bit time_t where possible
  xtensa: ISS: avoid struct timeval
  dlm: use SO_SNDTIMEO_NEW instead of SO_SNDTIMEO_OLD
  ...
2020-01-29 14:55:47 -08:00
Linus Torvalds
a4fe2b4d87 Printk changes for 5.6
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Merge tag 'printk-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

Pull printk update from Petr Mladek:
 "Prevent replaying log on all consoles"

* tag 'printk-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  printk: fix exclusive_console replaying
2020-01-29 14:53:23 -08:00
Linus Torvalds
6aee4badd8 Merge branch 'work.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull openat2 support from Al Viro:
 "This is the openat2() series from Aleksa Sarai.

  I'm afraid that the rest of namei stuff will have to wait - it got
  zero review the last time I'd posted #work.namei, and there had been a
  leak in the posted series I'd caught only last weekend. I was going to
  repost it on Monday, but the window opened and the odds of getting any
  review during that... Oh, well.

  Anyway, openat2 part should be ready; that _did_ get sane amount of
  review and public testing, so here it comes"

From Aleksa's description of the series:
 "For a very long time, extending openat(2) with new features has been
  incredibly frustrating. This stems from the fact that openat(2) is
  possibly the most famous counter-example to the mantra "don't silently
  accept garbage from userspace" -- it doesn't check whether unknown
  flags are present[1].

  This means that (generally) the addition of new flags to openat(2) has
  been fraught with backwards-compatibility issues (O_TMPFILE has to be
  defined as __O_TMPFILE|O_DIRECTORY|[O_RDWR or O_WRONLY] to ensure old
  kernels gave errors, since it's insecure to silently ignore the
  flag[2]). All new security-related flags therefore have a tough road
  to being added to openat(2).

  Furthermore, the need for some sort of control over VFS's path
  resolution (to avoid malicious paths resulting in inadvertent
  breakouts) has been a very long-standing desire of many userspace
  applications.

  This patchset is a revival of Al Viro's old AT_NO_JUMPS[3] patchset
  (which was a variant of David Drysdale's O_BENEATH patchset[4] which
  was a spin-off of the Capsicum project[5]) with a few additions and
  changes made based on the previous discussion within [6] as well as
  others I felt were useful.

  In line with the conclusions of the original discussion of
  AT_NO_JUMPS, the flag has been split up into separate flags. However,
  instead of being an openat(2) flag it is provided through a new
  syscall openat2(2) which provides several other improvements to the
  openat(2) interface (see the patch description for more details). The
  following new LOOKUP_* flags are added:

  LOOKUP_NO_XDEV:

     Blocks all mountpoint crossings (upwards, downwards, or through
     absolute links). Absolute pathnames alone in openat(2) do not
     trigger this. Magic-link traversal which implies a vfsmount jump is
     also blocked (though magic-link jumps on the same vfsmount are
     permitted).

  LOOKUP_NO_MAGICLINKS:

     Blocks resolution through /proc/$pid/fd-style links. This is done
     by blocking the usage of nd_jump_link() during resolution in a
     filesystem. The term "magic-links" is used to match with the only
     reference to these links in Documentation/, but I'm happy to change
     the name.

     It should be noted that this is different to the scope of
     ~LOOKUP_FOLLOW in that it applies to all path components. However,
     you can do openat2(NO_FOLLOW|NO_MAGICLINKS) on a magic-link and it
     will *not* fail (assuming that no parent component was a
     magic-link), and you will have an fd for the magic-link.

     In order to correctly detect magic-links, the introduction of a new
     LOOKUP_MAGICLINK_JUMPED state flag was required.

  LOOKUP_BENEATH:

     Disallows escapes to outside the starting dirfd's
     tree, using techniques such as ".." or absolute links. Absolute
     paths in openat(2) are also disallowed.

     Conceptually this flag is to ensure you "stay below" a certain
     point in the filesystem tree -- but this requires some additional
     to protect against various races that would allow escape using
     "..".

     Currently LOOKUP_BENEATH implies LOOKUP_NO_MAGICLINKS, because it
     can trivially beam you around the filesystem (breaking the
     protection). In future, there might be similar safety checks done
     as in LOOKUP_IN_ROOT, but that requires more discussion.

  In addition, two new flags are added that expand on the above ideas:

  LOOKUP_NO_SYMLINKS:

     Does what it says on the tin. No symlink resolution is allowed at
     all, including magic-links. Just as with LOOKUP_NO_MAGICLINKS this
     can still be used with NOFOLLOW to open an fd for the symlink as
     long as no parent path had a symlink component.

  LOOKUP_IN_ROOT:

     This is an extension of LOOKUP_BENEATH that, rather than blocking
     attempts to move past the root, forces all such movements to be
     scoped to the starting point. This provides chroot(2)-like
     protection but without the cost of a chroot(2) for each filesystem
     operation, as well as being safe against race attacks that
     chroot(2) is not.

     If a race is detected (as with LOOKUP_BENEATH) then an error is
     generated, and similar to LOOKUP_BENEATH it is not permitted to
     cross magic-links with LOOKUP_IN_ROOT.

     The primary need for this is from container runtimes, which
     currently need to do symlink scoping in userspace[7] when opening
     paths in a potentially malicious container.

     There is a long list of CVEs that could have bene mitigated by
     having RESOLVE_THIS_ROOT (such as CVE-2017-1002101,
     CVE-2017-1002102, CVE-2018-15664, and CVE-2019-5736, just to name a
     few).

  In order to make all of the above more usable, I'm working on
  libpathrs[8] which is a C-friendly library for safe path resolution.
  It features a userspace-emulated backend if the kernel doesn't support
  openat2(2). Hopefully we can get userspace to switch to using it, and
  thus get openat2(2) support for free once it's ready.

  Future work would include implementing things like
  RESOLVE_NO_AUTOMOUNT and possibly a RESOLVE_NO_REMOTE (to allow
  programs to be sure they don't hit DoSes though stale NFS handles)"

* 'work.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  Documentation: path-lookup: include new LOOKUP flags
  selftests: add openat2(2) selftests
  open: introduce openat2(2) syscall
  namei: LOOKUP_{IN_ROOT,BENEATH}: permit limited ".." resolution
  namei: LOOKUP_IN_ROOT: chroot-like scoped resolution
  namei: LOOKUP_BENEATH: O_BENEATH-like scoped resolution
  namei: LOOKUP_NO_XDEV: block mountpoint crossing
  namei: LOOKUP_NO_MAGICLINKS: block magic-link resolution
  namei: LOOKUP_NO_SYMLINKS: block symlink resolution
  namei: allow set_root() to produce errors
  namei: allow nd_jump_link() to produce errors
  nsfs: clean-up ns_get_path() signature to return int
  namei: only return -ECHILD from follow_dotdot_rcu()
2020-01-29 11:20:24 -08:00
Linus Torvalds
15d6632496 Merge branch 'urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU warning removal from Paul McKenney:
 "A single commit that fixes an embarrassing bug discussed here:

      https://lore.kernel.org/lkml/20200125131425.GB16136@zn.tnic/

  which apparently also affects smaller systems"

[ This was sent to Ingo, but since I see the issue on the laptop I use for
  testing during the merge window, I'm doing the pull directly     - Linus ]

* 'urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  rcu: Forgive slow expedited grace periods at boot time
2020-01-29 11:04:49 -08:00
Martin KaFai Lau
d3e42bb0a3 bpf: Reuse log from btf_prase_vmlinux() in btf_struct_ops_init()
Instead of using a locally defined "struct bpf_verifier_log log = {}",
btf_struct_ops_init() should reuse the "log" from its calling
function "btf_parse_vmlinux()".  It should also resolve the
frame-size too large compiler warning in some ARCH.

Fixes: 27ae7997a6 ("bpf: Introduce BPF_PROG_TYPE_STRUCT_OPS")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200127175145.1154438-1-kafai@fb.com
2020-01-29 16:40:54 +01:00
Masami Hiramatsu
5c3469cb89 tracing/boot: Move external function declarations to kernel/trace/trace.h
Move external function declarations into kernel/trace/trace.h
from trace_boot.c for tracing subsystem internal use.

Link: http://lkml.kernel.org/r/158029060405.12381.11944554430359702545.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-29 08:49:04 -05:00
Masami Hiramatsu
76a598ec8c tracing/boot: Include required headers and sort it alphabetically
Include some required (but currently indirectly included)
headers and sort it alphabetically.

Link: http://lkml.kernel.org/r/158029059514.12381.6597832266860248781.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-29 08:48:44 -05:00
Tom Zanussi
d0a497066f tracing: Add 'hist:' to hist trigger error log error string
The 'hist:' prefix gets stripped from the command text during command
processing, but should be added back when displaying the command
during error processing.

Not only because it's what should be displayed but also because not
having it means the test cases fail because the caret is miscalculated
by the length of the prefix string.

Link: http://lkml.kernel.org/r/449df721f560042e22382f67574bcc5b4d830d3d.1561743018.git.zanussi@kernel.org

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-28 23:17:10 -05:00
Tom Zanussi
4de26c8c96 tracing: Add hist trigger error messages for sort specification
Add error codes and messages for all the error paths leading to sort
specification parsing errors.

Link: http://lkml.kernel.org/r/237830dc05e583fbb53664d817a784297bf961be.1561743018.git.zanussi@kernel.org

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-28 23:16:44 -05:00
Tom Zanussi
b527b638fd tracing: Simplify assignment parsing for hist triggers
In the process of adding better error messages for sorting, I realized
that strsep was being used incorrectly and some of the error paths I
was expecting to be hit weren't and just fell through to the common
invalid key error case.

It also became obvious that for keyword assignments, it wasn't
necessary to save the full assignment and reparse it later, and having
a common empty-assignment check would also make more sense in terms of
error processing.

Change the code to fix these problems and simplify it for new error
message changes in a subsequent patch.

Link: http://lkml.kernel.org/r/1c3ef0b6655deaf345f6faee2584a0298ac2d743.1561743018.git.zanussi@kernel.org

Fixes: e62347d245 ("tracing: Add hist trigger support for user-defined sorting ('sort=' param)")
Fixes: 7ef224d1d0 ("tracing: Add 'hist' event trigger command")
Fixes: a4072fe85b ("tracing: Add a clock attribute for hist triggers")
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-28 23:16:27 -05:00
Linus Torvalds
fad7bdc9b0 This pull request contains the following changes for UML:
- Fix for time travel mode
 - Disable CONFIG_CONSTRUCTORS again
 - A new command line option to have an non-raw serial line
 - Preparations to remove obsolete UML network drivers
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Merge tag 'for-linus-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Anton Ivanov:
 "I am sending this on behalf of Richard who is traveling.

  This contains the following changes for UML:

   - Fix for time travel mode

   - Disable CONFIG_CONSTRUCTORS again

   - A new command line option to have an non-raw serial line

   - Preparations to remove obsolete UML network drivers"

* tag 'for-linus-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Fix time-travel=inf-cpu with xor/raid6
  Revert "um: Enable CONFIG_CONSTRUCTORS"
  um: Mark non-vector net transports as obsolete
  um: Add an option to make serial driver non-raw
2020-01-28 18:29:25 -08:00
Linus Torvalds
a78416d974 Kprobe events added "ustring" to distinguish reading strings from kernel space
or user space. But the creating of the event format file only checks for
 "string" to display string formats. "ustring" must also be handled.
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Merge tag 'trace-v5.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Kprobe events added 'ustring' to distinguish reading strings from
  kernel space or user space.

  But the creating of the event format file only checks for 'string' to
  display string formats. 'ustring' must also be handled"

* tag 'trace-v5.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/kprobes: Have uname use __get_str() in print_fmt
2020-01-28 18:26:09 -08:00
Linus Torvalds
bd2463ac7d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from David Miller:

 1) Add WireGuard

 2) Add HE and TWT support to ath11k driver, from John Crispin.

 3) Add ESP in TCP encapsulation support, from Sabrina Dubroca.

 4) Add variable window congestion control to TIPC, from Jon Maloy.

 5) Add BCM84881 PHY driver, from Russell King.

 6) Start adding netlink support for ethtool operations, from Michal
    Kubecek.

 7) Add XDP drop and TX action support to ena driver, from Sameeh
    Jubran.

 8) Add new ipv4 route notifications so that mlxsw driver does not have
    to handle identical routes itself. From Ido Schimmel.

 9) Add BPF dynamic program extensions, from Alexei Starovoitov.

10) Support RX and TX timestamping in igc, from Vinicius Costa Gomes.

11) Add support for macsec HW offloading, from Antoine Tenart.

12) Add initial support for MPTCP protocol, from Christoph Paasch,
    Matthieu Baerts, Florian Westphal, Peter Krystad, and many others.

13) Add Octeontx2 PF support, from Sunil Goutham, Geetha sowjanya, Linu
    Cherian, and others.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1469 commits)
  net: phy: add default ARCH_BCM_IPROC for MDIO_BCM_IPROC
  udp: segment looped gso packets correctly
  netem: change mailing list
  qed: FW 8.42.2.0 debug features
  qed: rt init valid initialization changed
  qed: Debug feature: ilt and mdump
  qed: FW 8.42.2.0 Add fw overlay feature
  qed: FW 8.42.2.0 HSI changes
  qed: FW 8.42.2.0 iscsi/fcoe changes
  qed: Add abstraction for different hsi values per chip
  qed: FW 8.42.2.0 Additional ll2 type
  qed: Use dmae to write to widebus registers in fw_funcs
  qed: FW 8.42.2.0 Parser offsets modified
  qed: FW 8.42.2.0 Queue Manager changes
  qed: FW 8.42.2.0 Expose new registers and change windows
  qed: FW 8.42.2.0 Internal ram offsets modifications
  MAINTAINERS: Add entry for Marvell OcteonTX2 Physical Function driver
  Documentation: net: octeontx2: Add RVU HW and drivers overview
  octeontx2-pf: ethtool RSS config support
  octeontx2-pf: Add basic ethtool support
  ...
2020-01-28 16:02:33 -08:00
Linus Torvalds
a78208e243 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
 "API:
   - Removed CRYPTO_TFM_RES flags
   - Extended spawn grabbing to all algorithm types
   - Moved hash descsize verification into API code

  Algorithms:
   - Fixed recursive pcrypt dead-lock
   - Added new 32 and 64-bit generic versions of poly1305
   - Added cryptogams implementation of x86/poly1305

  Drivers:
   - Added support for i.MX8M Mini in caam
   - Added support for i.MX8M Nano in caam
   - Added support for i.MX8M Plus in caam
   - Added support for A33 variant of SS in sun4i-ss
   - Added TEE support for Raven Ridge in ccp
   - Added in-kernel API to submit TEE commands in ccp
   - Added AMD-TEE driver
   - Added support for BCM2711 in iproc-rng200
   - Added support for AES256-GCM based ciphers for chtls
   - Added aead support on SEC2 in hisilicon"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (244 commits)
  crypto: arm/chacha - fix build failured when kernel mode NEON is disabled
  crypto: caam - add support for i.MX8M Plus
  crypto: x86/poly1305 - emit does base conversion itself
  crypto: hisilicon - fix spelling mistake "disgest" -> "digest"
  crypto: chacha20poly1305 - add back missing test vectors and test chunking
  crypto: x86/poly1305 - fix .gitignore typo
  tee: fix memory allocation failure checks on drv_data and amdtee
  crypto: ccree - erase unneeded inline funcs
  crypto: ccree - make cc_pm_put_suspend() void
  crypto: ccree - split overloaded usage of irq field
  crypto: ccree - fix PM race condition
  crypto: ccree - fix FDE descriptor sequence
  crypto: ccree - cc_do_send_request() is void func
  crypto: ccree - fix pm wrongful error reporting
  crypto: ccree - turn errors to debug msgs
  crypto: ccree - fix AEAD decrypt auth fail
  crypto: ccree - fix typo in comment
  crypto: ccree - fix typos in error msgs
  crypto: atmel-{aes,sha,tdes} - Retire crypto_platform_data
  crypto: x86/sha - Eliminate casts on asm implementations
  ...
2020-01-28 15:38:56 -08:00
Konstantin Khlebnikov
b4fb015eef sched/rt: Optimize checking group RT scheduler constraints
Group RT scheduler contains protection against setting zero runtime for
cgroup with RT tasks. Right now function tg_set_rt_bandwidth() iterates
over all CPU cgroups and calls tg_has_rt_tasks() for any cgroup which
runtime is zero (not only for changed one). Default RT runtime is zero,
thus tg_has_rt_tasks() will is called for almost at CPU cgroups.

This protection already is slightly racy: runtime limit could be changed
between cpu_cgroup_can_attach() and cpu_cgroup_attach() because changing
cgroup attribute does not lock cgroup_mutex while attach does not lock
rt_constraints_mutex. Changing task scheduler class also races with
changing rt runtime: check in __sched_setscheduler() isn't protected.

Function tg_has_rt_tasks() iterates over all threads in the system.
This gives NR_CGROUPS * NR_TASKS operations under single tasklist_lock
locked for read tg_set_rt_bandwidth(). Any concurrent attempt of locking
tasklist_lock for write (for example fork) will stuck with disabled irqs.

This patch makes two optimizations:
1) Remove locking tasklist_lock and iterate only tasks in cgroup
2) Call tg_has_rt_tasks() iff rt runtime changes from non-zero to zero

All changed code is under CONFIG_RT_GROUP_SCHED.

Testcase:

 # mkdir /sys/fs/cgroup/cpu/test{1..10000}
 # echo 0 | tee /sys/fs/cgroup/cpu/test*/cpu.rt_runtime_us

At the same time without patch fork time will be >100ms:

 # perf trace -e clone --duration 100 stress-ng --fork 1

Also remote ping will show timings >100ms caused by irq latency.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/157996383820.4651.11292439232549211693.stgit@buzz
2020-01-28 21:37:09 +01:00
Srikar Dronamraju
bec2860a2b sched/fair: Optimize select_idle_core()
Currently we loop through all threads of a core to evaluate if the core is
idle or not. This is unnecessary. If a thread of a core is not idle, skip
evaluating other threads of a core. Also while clearing the cpumask, bits
of all CPUs of a core can be cleared in one-shot.

Collecting ticks on a Power 9 SMT 8 system around select_idle_core
while running schbench shows us

(units are in ticks, hence lesser is better)
Without patch
    N        Min     Max     Median         Avg      Stddev
x 130        151    1083        284   322.72308   144.41494

With patch
    N        Min     Max     Median         Avg      Stddev   Improvement
x 164         88     610        201   225.79268   106.78943        30.03%

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lkml.kernel.org/r/20191206172422.6578-1-srikar@linux.vnet.ibm.com
2020-01-28 21:37:08 +01:00
Giovanni Gherdovich
1567c3e346 x86, sched: Add support for frequency invariance
Implement arch_scale_freq_capacity() for 'modern' x86. This function
is used by the scheduler to correctly account usage in the face of
DVFS.

The present patch addresses Intel processors specifically and has positive
performance and performance-per-watt implications for the schedutil cpufreq
governor, bringing it closer to, if not on-par with, the powersave governor
from the intel_pstate driver/framework.

Large performance gains are obtained when the machine is lightly loaded and
no regression are observed at saturation. The benchmarks with the largest
gains are kernel compilation, tbench (the networking version of dbench) and
shell-intensive workloads.

1. FREQUENCY INVARIANCE: MOTIVATION
   * Without it, a task looks larger if the CPU runs slower

2. PECULIARITIES OF X86
   * freq invariance accounting requires knowing the ratio freq_curr/freq_max
   2.1 CURRENT FREQUENCY
       * Use delta_APERF / delta_MPERF * freq_base (a.k.a "BusyMHz")
   2.2 MAX FREQUENCY
       * It varies with time (turbo). As an approximation, we set it to a
         constant, i.e. 4-cores turbo frequency.

3. EFFECTS ON THE SCHEDUTIL FREQUENCY GOVERNOR
   * The invariant schedutil's formula has no feedback loop and reacts faster
     to utilization changes

4. KNOWN LIMITATIONS
   * In some cases tasks can't reach max util despite how hard they try

5. PERFORMANCE TESTING
   5.1 MACHINES
       * Skylake, Broadwell, Haswell
   5.2 SETUP
       * baseline Linux v5.2 w/ non-invariant schedutil. Tested freq_max = 1-2-3-4-8-12
         active cores turbo w/ invariant schedutil, and intel_pstate/powersave
   5.3 BENCHMARK RESULTS
       5.3.1 NEUTRAL BENCHMARKS
             * NAS Parallel Benchmark (HPC), hackbench
       5.3.2 NON-NEUTRAL BENCHMARKS
             * tbench (10-30% better), kernbench (10-15% better),
               shell-intensive-scripts (30-50% better)
             * no regressions
       5.3.3 SELECTION OF DETAILED RESULTS
       5.3.4 POWER CONSUMPTION, PERFORMANCE-PER-WATT
             * dbench (5% worse on one machine), kernbench (3% worse),
               tbench (5-10% better), shell-intensive-scripts (10-40% better)

6. MICROARCH'ES ADDRESSED HERE
   * Xeon Core before Scalable Performance processors line (Xeon Gold/Platinum
     etc have different MSRs semantic for querying turbo levels)

7. REFERENCES
   * MMTests performance testing framework, github.com/gormanm/mmtests

 +-------------------------------------------------------------------------+
 | 1. FREQUENCY INVARIANCE: MOTIVATION
 +-------------------------------------------------------------------------+

For example; suppose a CPU has two frequencies: 500 and 1000 Mhz. When
running a task that would consume 1/3rd of a CPU at 1000 MHz, it would
appear to consume 2/3rd (or 66.6%) when running at 500 MHz, giving the
false impression this CPU is almost at capacity, even though it can go
faster [*]. In a nutshell, without frequency scale-invariance tasks look
larger just because the CPU is running slower.

[*] (footnote: this assumes a linear frequency/performance relation; which
everybody knows to be false, but given realities its the best approximation
we can make.)

 +-------------------------------------------------------------------------+
 | 2. PECULIARITIES OF X86
 +-------------------------------------------------------------------------+

Accounting for frequency changes in PELT signals requires the computation of
the ratio freq_curr / freq_max. On x86 neither of those terms is readily
available.

2.1 CURRENT FREQUENCY
====================

Since modern x86 has hardware control over the actual frequency we run
at (because amongst other things, Turbo-Mode), we cannot simply use
the frequency as requested through cpufreq.

Instead we use the APERF/MPERF MSRs to compute the effective frequency
over the recent past. Also, because reading MSRs is expensive, don't
do so every time we need the value, but amortize the cost by doing it
every tick.

2.2 MAX FREQUENCY
=================

Obtaining freq_max is also non-trivial because at any time the hardware can
provide a frequency boost to a selected subset of cores if the package has
enough power to spare (eg: Turbo Boost). This means that the maximum frequency
available to a given core changes with time.

The approach taken in this change is to arbitrarily set freq_max to a constant
value at boot. The value chosen is the "4-cores (4C) turbo frequency" on most
microarchitectures, after evaluating the following candidates:

    * 1-core (1C) turbo frequency (the fastest turbo state available)
    * around base frequency (a.k.a. max P-state)
    * something in between, such as 4C turbo

To interpret these options, consider that this is the denominator in
freq_curr/freq_max, and that ratio will be used to scale PELT signals such as
util_avg and load_avg. A large denominator will undershoot (util_avg looks a
bit smaller than it really is), viceversa with a smaller denominator PELT
signals will tend to overshoot. Given that PELT drives frequency selection
in the schedutil governor, we will have:

    freq_max set to     | effect on DVFS
    --------------------+------------------
    1C turbo            | power efficiency (lower freq choices)
    base freq           | performance (higher util_avg, higher freq requests)
    4C turbo            | a bit of both

4C turbo proves to be a good compromise in a number of benchmarks (see below).

 +-------------------------------------------------------------------------+
 | 3. EFFECTS ON THE SCHEDUTIL FREQUENCY GOVERNOR
 +-------------------------------------------------------------------------+

Once an architecture implements a frequency scale-invariant utilization (the
PELT signal util_avg), schedutil switches its frequency selection formula from

    freq_next = 1.25 * freq_curr * util            [non-invariant util signal]

to

    freq_next = 1.25 * freq_max * util             [invariant util signal]

where, in the second formula, freq_max is set to the 1C turbo frequency (max
turbo). The advantage of the second formula, whose usage we unlock with this
patch, is that freq_next doesn't depend on the current frequency in an
iterative fashion, but can jump to any frequency in a single update. This
absence of feedback in the formula makes it quicker to react to utilization
changes and more robust against pathological instabilities.

Compare it to the update formula of intel_pstate/powersave:

    freq_next = 1.25 * freq_max * Busy%

where again freq_max is 1C turbo and Busy% is the percentage of time not spent
idling (calculated with delta_MPERF / delta_TSC); essentially the same as
invariant schedutil, and largely responsible for intel_pstate/powersave good
reputation. The non-invariant schedutil formula is derived from the invariant
one by approximating util_inv with util_raw * freq_curr / freq_max, but this
has limitations.

Testing shows improved performances due to better frequency selections when
the machine is lightly loaded, and essentially no change in behaviour at
saturation / overutilization.

 +-------------------------------------------------------------------------+
 | 4. KNOWN LIMITATIONS
 +-------------------------------------------------------------------------+

It's been shown that it is possible to create pathological scenarios where a
CPU-bound task cannot reach max utilization, if the normalizing factor
freq_max is fixed to a constant value (see [Lelli-2018]).

If freq_max is set to 4C turbo as we do here, one needs to peg at least 5
cores in a package doing some busywork, and observe that none of those task
will ever reach max util (1024) because they're all running at less than the
4C turbo frequency.

While this concern still applies, we believe the performance benefit of
frequency scale-invariant PELT signals outweights the cost of this limitation.

 [Lelli-2018]
 https://lore.kernel.org/lkml/20180517150418.GF22493@localhost.localdomain/

 +-------------------------------------------------------------------------+
 | 5. PERFORMANCE TESTING
 +-------------------------------------------------------------------------+

5.1 MACHINES
============

We tested the patch on three machines, with Skylake, Broadwell and Haswell
CPUs. The details are below, together with the available turbo ratios as
reported by the appropriate MSRs.

* 8x-SKYLAKE-UMA:
  Single socket E3-1240 v5, Skylake 4 cores/8 threads
  Max EFFiciency, BASE frequency and available turbo levels (MHz):

    EFFIC    800 |********
    BASE    3500 |***********************************
    4C      3700 |*************************************
    3C      3800 |**************************************
    2C      3900 |***************************************
    1C      3900 |***************************************

* 80x-BROADWELL-NUMA:
  Two sockets E5-2698 v4, 2x Broadwell 20 cores/40 threads
  Max EFFiciency, BASE frequency and available turbo levels (MHz):

    EFFIC   1200 |************
    BASE    2200 |**********************
    8C      2900 |*****************************
    7C      3000 |******************************
    6C      3100 |*******************************
    5C      3200 |********************************
    4C      3300 |*********************************
    3C      3400 |**********************************
    2C      3600 |************************************
    1C      3600 |************************************

* 48x-HASWELL-NUMA
  Two sockets E5-2670 v3, 2x Haswell 12 cores/24 threads
  Max EFFiciency, BASE frequency and available turbo levels (MHz):

    EFFIC   1200 |************
    BASE    2300 |***********************
    12C     2600 |**************************
    11C     2600 |**************************
    10C     2600 |**************************
    9C      2600 |**************************
    8C      2600 |**************************
    7C      2600 |**************************
    6C      2600 |**************************
    5C      2700 |***************************
    4C      2800 |****************************
    3C      2900 |*****************************
    2C      3100 |*******************************
    1C      3100 |*******************************

5.2 SETUP
=========

* The baseline is Linux v5.2 with schedutil (non-invariant) and the intel_pstate
  driver in passive mode.
* The rationale for choosing the various freq_max values to test have been to
  try all the 1-2-3-4C turbo levels (note that 1C and 2C turbo are identical
  on all machines), plus one more value closer to base_freq but still in the
  turbo range (8C turbo for both 80x-BROADWELL-NUMA and 48x-HASWELL-NUMA).
* In addition we've run all tests with intel_pstate/powersave for comparison.
* The filesystem is always XFS, the userspace is openSUSE Leap 15.1.
* 8x-SKYLAKE-UMA is capable of HWP (Hardware-Managed P-States), so the runs
  with active intel_pstate on this machine use that.

This gives, in terms of combinations tested on each machine:

* 8x-SKYLAKE-UMA
  * Baseline: Linux v5.2, non-invariant schedutil, intel_pstate passive
  * intel_pstate active + powersave + HWP
  * invariant schedutil, freq_max = 1C turbo
  * invariant schedutil, freq_max = 3C turbo
  * invariant schedutil, freq_max = 4C turbo

* both 80x-BROADWELL-NUMA and 48x-HASWELL-NUMA
  * [same as 8x-SKYLAKE-UMA, but no HWP capable]
  * invariant schedutil, freq_max = 8C turbo
    (which on 48x-HASWELL-NUMA is the same as 12C turbo, or "all cores turbo")

5.3 BENCHMARK RESULTS
=====================

5.3.1 NEUTRAL BENCHMARKS
------------------------

Tests that didn't show any measurable difference in performance on any of the
test machines between non-invariant schedutil and our patch are:

* NAS Parallel Benchmarks (NPB) using either MPI or openMP for IPC, any
  computational kernel
* flexible I/O (FIO)
* hackbench (using threads or processes, and using pipes or sockets)

5.3.2 NON-NEUTRAL BENCHMARKS
----------------------------

What follow are summary tables where each benchmark result is given a score.

* A tilde (~) means a neutral result, i.e. no difference from baseline.
* Scores are computed with the ratio result_new / result_baseline, so a tilde
  means a score of 1.00.
* The results in the score ratio are the geometric means of results running
  the benchmark with different parameters (eg: for kernbench: using 1, 2, 4,
  ... number of processes; for pgbench: varying the number of clients, and so
  on).
* The first three tables show higher-is-better kind of tests (i.e. measured in
  operations/second), the subsequent three show lower-is-better kind of tests
  (i.e. the workload is fixed and we measure elapsed time, think kernbench).
* "gitsource" is a name we made up for the test consisting in running the
  entire unit tests suite of the Git SCM and measuring how long it takes. We
  take it as a typical example of shell-intensive serialized workload.
* In the "I_PSTATE" column we have the results for intel_pstate/powersave. Other
  columns show invariant schedutil for different values of freq_max. 4C turbo
  is circled as it's the value we've chosen for the final implementation.

80x-BROADWELL-NUMA (comparison ratio; higher is better)
                                         +------+
                 I_PSTATE   1C     3C    | 4C   |  8C
pgbench-ro           1.14   ~      ~     | 1.11 |  1.14
pgbench-rw           ~      ~      ~     | ~    |  ~
netperf-udp          1.06   ~      1.06  | 1.05 |  1.07
netperf-tcp          ~      1.03   ~     | 1.01 |  1.02
tbench4              1.57   1.18   1.22  | 1.30 |  1.56
                                         +------+

8x-SKYLAKE-UMA (comparison ratio; higher is better)
                                         +------+
             I_PSTATE/HWP   1C     3C    | 4C   |
pgbench-ro           ~      ~      ~     | ~    |
pgbench-rw           ~      ~      ~     | ~    |
netperf-udp          ~      ~      ~     | ~    |
netperf-tcp          ~      ~      ~     | ~    |
tbench4              1.30   1.14   1.14  | 1.16 |
                                         +------+

48x-HASWELL-NUMA (comparison ratio; higher is better)
                                         +------+
                 I_PSTATE   1C     3C    | 4C   |  12C
pgbench-ro           1.15   ~      ~     | 1.06 |  1.16
pgbench-rw           ~      ~      ~     | ~    |  ~
netperf-udp          1.05   0.97   1.04  | 1.04 |  1.02
netperf-tcp          0.96   1.01   1.01  | 1.01 |  1.01
tbench4              1.50   1.05   1.13  | 1.13 |  1.25
                                         +------+

In the table above we see that active intel_pstate is slightly better than our
4C-turbo patch (both in reference to the baseline non-invariant schedutil) on
read-only pgbench and much better on tbench. Both cases are notable in which
it shows that lowering our freq_max (to 8C-turbo and 12C-turbo on
80x-BROADWELL-NUMA and 48x-HASWELL-NUMA respectively) helps invariant
schedutil to get closer.

If we ignore active intel_pstate and focus on the comparison with baseline
alone, there are several instances of double-digit performance improvement.

80x-BROADWELL-NUMA (comparison ratio; lower is better)
                                         +------+
                 I_PSTATE   1C     3C    | 4C   |  8C
dbench4              1.23   0.95   0.95  | 0.95 |  0.95
kernbench            0.93   0.83   0.83  | 0.83 |  0.82
gitsource            0.98   0.49   0.49  | 0.49 |  0.48
                                         +------+

8x-SKYLAKE-UMA (comparison ratio; lower is better)
                                         +------+
             I_PSTATE/HWP   1C     3C    | 4C   |
dbench4              ~      ~      ~     | ~    |
kernbench            ~      ~      ~     | ~    |
gitsource            0.92   0.55   0.55  | 0.55 |
                                         +------+

48x-HASWELL-NUMA (comparison ratio; lower is better)
                                         +------+
                 I_PSTATE   1C     3C    | 4C   |  8C
dbench4              ~      ~      ~     | ~    |  ~
kernbench            0.94   0.90   0.89  | 0.90 |  0.90
gitsource            0.97   0.69   0.69  | 0.69 |  0.69
                                         +------+

dbench is not very remarkable here, unless we notice how poorly active
intel_pstate is performing on 80x-BROADWELL-NUMA: 23% regression versus
non-invariant schedutil. We repeated that run getting consistent results. Out
of scope for the patch at hand, but deserving future investigation. Other than
that, we previously ran this campaign with Linux v5.0 and saw the patch doing
better on dbench a the time. We haven't checked closely and can only speculate
at this point.

On the NUMA boxes kernbench gets 10-15% improvements on average; we'll see in
the detailed tables that the gains concentrate on low process counts (lightly
loaded machines).

The test we call "gitsource" (running the git unit test suite, a long-running
single-threaded shell script) appears rather spectacular in this table (gains
of 30-50% depending on the machine). It is to be noted, however, that
gitsource has no adjustable parameters (such as the number of jobs in
kernbench, which we average over in order to get a single-number summary
score) and is exactly the kind of low-parallelism workload that benefits the
most from this patch. When looking at the detailed tables of kernbench or
tbench4, at low process or client counts one can see similar numbers.

5.3.3 SELECTION OF DETAILED RESULTS
-----------------------------------

Machine            : 48x-HASWELL-NUMA
Benchmark          : tbench4 (i.e. dbench4 over the network, actually loopback)
Varying parameter  : number of clients
Unit               : MB/sec (higher is better)

                   5.2.0 vanilla (BASELINE)               5.2.0 intel_pstate                   5.2.0 1C-turbo
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hmean  1        126.73  +- 0.31% (        )      315.91  +- 0.66% ( 149.28%)      125.03  +- 0.76% (  -1.34%)
Hmean  2        258.04  +- 0.62% (        )      614.16  +- 0.51% ( 138.01%)      269.58  +- 1.45% (   4.47%)
Hmean  4        514.30  +- 0.67% (        )     1146.58  +- 0.54% ( 122.94%)      533.84  +- 1.99% (   3.80%)
Hmean  8       1111.38  +- 2.52% (        )     2159.78  +- 0.38% (  94.33%)     1359.92  +- 1.56% (  22.36%)
Hmean  16      2286.47  +- 1.36% (        )     3338.29  +- 0.21% (  46.00%)     2720.20  +- 0.52% (  18.97%)
Hmean  32      4704.84  +- 0.35% (        )     4759.03  +- 0.43% (   1.15%)     4774.48  +- 0.30% (   1.48%)
Hmean  64      7578.04  +- 0.27% (        )     7533.70  +- 0.43% (  -0.59%)     7462.17  +- 0.65% (  -1.53%)
Hmean  128     6998.52  +- 0.16% (        )     6987.59  +- 0.12% (  -0.16%)     6909.17  +- 0.14% (  -1.28%)
Hmean  192     6901.35  +- 0.25% (        )     6913.16  +- 0.10% (   0.17%)     6855.47  +- 0.21% (  -0.66%)

                             5.2.0 3C-turbo                   5.2.0 4C-turbo                  5.2.0 12C-turbo
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hmean  1        128.43  +- 0.28% (   1.34%)      130.64  +- 3.81% (   3.09%)      153.71  +- 5.89% (  21.30%)
Hmean  2        311.70  +- 6.15% (  20.79%)      281.66  +- 3.40% (   9.15%)      305.08  +- 5.70% (  18.23%)
Hmean  4        641.98  +- 2.32% (  24.83%)      623.88  +- 5.28% (  21.31%)      906.84  +- 4.65% (  76.32%)
Hmean  8       1633.31  +- 1.56% (  46.96%)     1714.16  +- 0.93% (  54.24%)     2095.74  +- 0.47% (  88.57%)
Hmean  16      3047.24  +- 0.42% (  33.27%)     3155.02  +- 0.30% (  37.99%)     3634.58  +- 0.15% (  58.96%)
Hmean  32      4734.31  +- 0.60% (   0.63%)     4804.38  +- 0.23% (   2.12%)     4674.62  +- 0.27% (  -0.64%)
Hmean  64      7699.74  +- 0.35% (   1.61%)     7499.72  +- 0.34% (  -1.03%)     7659.03  +- 0.25% (   1.07%)
Hmean  128     6935.18  +- 0.15% (  -0.91%)     6942.54  +- 0.10% (  -0.80%)     7004.85  +- 0.12% (   0.09%)
Hmean  192     6901.62  +- 0.12% (   0.00%)     6856.93  +- 0.10% (  -0.64%)     6978.74  +- 0.10% (   1.12%)

This is one of the cases where the patch still can't surpass active
intel_pstate, not even when freq_max is as low as 12C-turbo. Otherwise, gains are
visible up to 16 clients and the saturated scenario is the same as baseline.

The scores in the summary table from the previous sections are ratios of
geometric means of the results over different clients, as seen in this table.

Machine            : 80x-BROADWELL-NUMA
Benchmark          : kernbench (kernel compilation)
Varying parameter  : number of jobs
Unit               : seconds (lower is better)

                   5.2.0 vanilla (BASELINE)               5.2.0 intel_pstate                   5.2.0 1C-turbo
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean  2        379.68  +- 0.06% (        )      330.20  +- 0.43% (  13.03%)      285.93  +- 0.07% (  24.69%)
Amean  4        200.15  +- 0.24% (        )      175.89  +- 0.22% (  12.12%)      153.78  +- 0.25% (  23.17%)
Amean  8        106.20  +- 0.31% (        )       95.54  +- 0.23% (  10.03%)       86.74  +- 0.10% (  18.32%)
Amean  16        56.96  +- 1.31% (        )       53.25  +- 1.22% (   6.50%)       48.34  +- 1.73% (  15.13%)
Amean  32        34.80  +- 2.46% (        )       33.81  +- 0.77% (   2.83%)       30.28  +- 1.59% (  12.99%)
Amean  64        26.11  +- 1.63% (        )       25.04  +- 1.07% (   4.10%)       22.41  +- 2.37% (  14.16%)
Amean  128       24.80  +- 1.36% (        )       23.57  +- 1.23% (   4.93%)       21.44  +- 1.37% (  13.55%)
Amean  160       24.85  +- 0.56% (        )       23.85  +- 1.17% (   4.06%)       21.25  +- 1.12% (  14.49%)

                             5.2.0 3C-turbo                   5.2.0 4C-turbo                   5.2.0 8C-turbo
- - - - - - - -  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean  2        284.08  +- 0.13% (  25.18%)      283.96  +- 0.51% (  25.21%)      285.05  +- 0.21% (  24.92%)
Amean  4        153.18  +- 0.22% (  23.47%)      154.70  +- 1.64% (  22.71%)      153.64  +- 0.30% (  23.24%)
Amean  8         87.06  +- 0.28% (  18.02%)       86.77  +- 0.46% (  18.29%)       86.78  +- 0.22% (  18.28%)
Amean  16        48.03  +- 0.93% (  15.68%)       47.75  +- 1.99% (  16.17%)       47.52  +- 1.61% (  16.57%)
Amean  32        30.23  +- 1.20% (  13.14%)       30.08  +- 1.67% (  13.57%)       30.07  +- 1.67% (  13.60%)
Amean  64        22.59  +- 2.02% (  13.50%)       22.63  +- 0.81% (  13.32%)       22.42  +- 0.76% (  14.12%)
Amean  128       21.37  +- 0.67% (  13.82%)       21.31  +- 1.15% (  14.07%)       21.17  +- 1.93% (  14.63%)
Amean  160       21.68  +- 0.57% (  12.76%)       21.18  +- 1.74% (  14.77%)       21.22  +- 1.00% (  14.61%)

The patch outperform active intel_pstate (and baseline) by a considerable
margin; the summary table from the previous section says 4C turbo and active
intel_pstate are 0.83 and 0.93 against baseline respectively, so 4C turbo is
0.83/0.93=0.89 against intel_pstate (~10% better on average). There is no
noticeable difference with regard to the value of freq_max.

Machine            : 8x-SKYLAKE-UMA
Benchmark          : gitsource (time to run the git unit test suite)
Varying parameter  : none
Unit               : seconds (lower is better)

                            5.2.0 vanilla           5.2.0 intel_pstate/hwp         5.2.0 1C-turbo
- - - - - - - -  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean         858.85  +- 1.16% (        )      791.94  +- 0.21% (   7.79%)      474.95 (  44.70%)

                           5.2.0 3C-turbo                   5.2.0 4C-turbo
- - - - - - - -  - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean         475.26  +- 0.20% (  44.66%)      474.34  +- 0.13% (  44.77%)

In this test, which is of interest as representing shell-intensive
(i.e. fork-intensive) serialized workloads, invariant schedutil outperforms
intel_pstate/powersave by a whopping 40% margin.

5.3.4 POWER CONSUMPTION, PERFORMANCE-PER-WATT
---------------------------------------------

The following table shows average power consumption in watt for each
benchmark. Data comes from turbostat (package average), which in turn is read
from the RAPL interface on CPUs. We know the patch affects CPU frequencies so
it's reasonable to ignore other power consumers (such as memory or I/O). Also,
we don't have a power meter available in the lab so RAPL is the best we have.

turbostat sampled average power every 10 seconds for the entire duration of
each benchmark. We took all those values and averaged them (i.e. with don't
have detail on a per-parameter granularity, only on whole benchmarks).

80x-BROADWELL-NUMA (power consumption, watts)
                                                    +--------+
               BASELINE I_PSTATE       1C       3C  |     4C |      8C
pgbench-ro       130.01   142.77   131.11   132.45  | 134.65 |  136.84
pgbench-rw        68.30    60.83    71.45    71.70  |  71.65 |   72.54
dbench4           90.25    59.06   101.43    99.89  | 101.10 |  102.94
netperf-udp       65.70    69.81    66.02    68.03  |  68.27 |   68.95
netperf-tcp       88.08    87.96    88.97    88.89  |  88.85 |   88.20
tbench4          142.32   176.73   153.02   163.91  | 165.58 |  176.07
kernbench         92.94   101.95   114.91   115.47  | 115.52 |  115.10
gitsource         40.92    41.87    75.14    75.20  |  75.40 |   75.70
                                                    +--------+
8x-SKYLAKE-UMA (power consumption, watts)
                                                    +--------+
              BASELINE I_PSTATE/HWP    1C       3C  |     4C |
pgbench-ro        46.49    46.68    46.56    46.59  |  46.52 |
pgbench-rw        29.34    31.38    30.98    31.00  |  31.00 |
dbench4           27.28    27.37    27.49    27.41  |  27.38 |
netperf-udp       22.33    22.41    22.36    22.35  |  22.36 |
netperf-tcp       27.29    27.29    27.30    27.31  |  27.33 |
tbench4           41.13    45.61    43.10    43.33  |  43.56 |
kernbench         42.56    42.63    43.01    43.01  |  43.01 |
gitsource         13.32    13.69    17.33    17.30  |  17.35 |
                                                    +--------+
48x-HASWELL-NUMA (power consumption, watts)
                                                    +--------+
               BASELINE I_PSTATE       1C       3C  |     4C |     12C
pgbench-ro       128.84   136.04   129.87   132.43  | 132.30 |  134.86
pgbench-rw        37.68    37.92    37.17    37.74  |  37.73 |   37.31
dbench4           28.56    28.73    28.60    28.73  |  28.70 |   28.79
netperf-udp       56.70    60.44    56.79    57.42  |  57.54 |   57.52
netperf-tcp       75.49    75.27    75.87    76.02  |  76.01 |   75.95
tbench4          115.44   139.51   119.53   123.07  | 123.97 |  130.22
kernbench         83.23    91.55    95.58    95.69  |  95.72 |   96.04
gitsource         36.79    36.99    39.99    40.34  |  40.35 |   40.23
                                                    +--------+

A lower power consumption isn't necessarily better, it depends on what is done
with that energy. Here are tables with the ratio of performance-per-watt on
each machine and benchmark. Higher is always better; a tilde (~) means a
neutral ratio (i.e. 1.00).

80x-BROADWELL-NUMA (performance-per-watt ratios; higher is better)
                                     +------+
             I_PSTATE     1C     3C  |   4C |    8C
pgbench-ro       1.04   1.06   0.94  | 1.07 |  1.08
pgbench-rw       1.10   0.97   0.96  | 0.96 |  0.97
dbench4          1.24   0.94   0.95  | 0.94 |  0.92
netperf-udp      ~      1.02   1.02  | ~    |  1.02
netperf-tcp      ~      1.02   ~     | ~    |  1.02
tbench4          1.26   1.10   1.06  | 1.12 |  1.26
kernbench        0.98   0.97   0.97  | 0.97 |  0.98
gitsource        ~      1.11   1.11  | 1.11 |  1.13
                                     +------+

8x-SKYLAKE-UMA (performance-per-watt ratios; higher is better)
                                     +------+
         I_PSTATE/HWP     1C     3C  |   4C |
pgbench-ro       ~      ~      ~     | ~    |
pgbench-rw       0.95   0.97   0.96  | 0.96 |
dbench4          ~      ~      ~     | ~    |
netperf-udp      ~      ~      ~     | ~    |
netperf-tcp      ~      ~      ~     | ~    |
tbench4          1.17   1.09   1.08  | 1.10 |
kernbench        ~      ~      ~     | ~    |
gitsource        1.06   1.40   1.40  | 1.40 |
                                     +------+

48x-HASWELL-NUMA  (performance-per-watt ratios; higher is better)
                                     +------+
             I_PSTATE     1C     3C  |   4C |   12C
pgbench-ro       1.09   ~      1.09  | 1.03 |  1.11
pgbench-rw       ~      0.86   ~     | ~    |  0.86
dbench4          ~      1.02   1.02  | 1.02 |  ~
netperf-udp      ~      0.97   1.03  | 1.02 |  ~
netperf-tcp      0.96   ~      ~     | ~    |  ~
tbench4          1.24   ~      1.06  | 1.05 |  1.11
kernbench        0.97   0.97   0.98  | 0.97 |  0.96
gitsource        1.03   1.33   1.32  | 1.32 |  1.33
                                     +------+

These results are overall pleasing: in plenty of cases we observe
performance-per-watt improvements. The few regressions (read/write pgbench and
dbench on the Broadwell machine) are of small magnitude. kernbench loses a few
percentage points (it has a 10-15% performance improvement, but apparently the
increase in power consumption is larger than that). tbench4 and gitsource, which
benefit the most from the patch, keep a positive score in this table which is
a welcome surprise; that suggests that in those particular workloads the
non-invariant schedutil (and active intel_pstate, too) makes some rather
suboptimal frequency selections.

+-------------------------------------------------------------------------+
| 6. MICROARCH'ES ADDRESSED HERE
+-------------------------------------------------------------------------+

The patch addresses Xeon Core processors that use MSR_PLATFORM_INFO and
MSR_TURBO_RATIO_LIMIT to advertise their base frequency and turbo frequencies
respectively. This excludes the recent Xeon Scalable Performance processors
line (Xeon Gold, Platinum etc) whose MSRs have to be parsed differently.

Subsequent patches will address:

* Xeon Scalable Performance processors and Atom Goldmont/Goldmont Plus
* Xeon Phi (Knights Landing, Knights Mill)
* Atom Silvermont

+-------------------------------------------------------------------------+
| 7. REFERENCES
+-------------------------------------------------------------------------+

Tests have been run with the help of the MMTests performance testing
framework, see github.com/gormanm/mmtests. The configuration file names for
the benchmark used are:

    db-pgbench-timed-ro-small-xfs
    db-pgbench-timed-rw-small-xfs
    io-dbench4-async-xfs
    network-netperf-unbound
    network-tbench
    scheduler-unbound
    workload-kerndevel-xfs
    workload-shellscripts-xfs
    hpc-nas-c-class-mpi-full-xfs
    hpc-nas-c-class-omp-full

All those benchmarks are generally available on the web:

pgbench: https://www.postgresql.org/docs/10/pgbench.html
netperf: https://hewlettpackard.github.io/netperf/
dbench/tbench: https://dbench.samba.org/
gitsource: git unit test suite, github.com/git/git
NAS Parallel Benchmarks: https://www.nas.nasa.gov/publications/npb.html
hackbench: https://people.redhat.com/mingo/cfs-scheduler/tools/hackbench.c

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Doug Smythies <dsmythies@telus.net>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20200122151617.531-2-ggherdovich@suse.cz
2020-01-28 21:36:59 +01:00
Vincent Guittot
2a4b03ffc6 sched/fair: Prevent unlimited runtime on throttled group
When a running task is moved on a throttled task group and there is no
other task enqueued on the CPU, the task can keep running using 100% CPU
whatever the allocated bandwidth for the group and although its cfs rq is
throttled. Furthermore, the group entity of the cfs_rq and its parents are
not enqueued but only set as curr on their respective cfs_rqs.

We have the following sequence:

sched_move_task
  -dequeue_task: dequeue task and group_entities.
  -put_prev_task: put task and group entities.
  -sched_change_group: move task to new group.
  -enqueue_task: enqueue only task but not group entities because cfs_rq is
    throttled.
  -set_next_task : set task and group_entities as current sched_entity of
    their cfs_rq.

Another impact is that the root cfs_rq runnable_load_avg at root rq stays
null because the group_entities are not enqueued. This situation will stay
the same until an "external" event triggers a reschedule. Let trigger it
immediately instead.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Ben Segall <bsegall@google.com>
Link: https://lkml.kernel.org/r/1579011236-31256-1-git-send-email-vincent.guittot@linaro.org
2020-01-28 21:36:58 +01:00
Wanpeng Li
e938b9c941 sched/nohz: Optimize get_nohz_timer_target()
On a machine, CPU 0 is used for housekeeping, the other 39 CPUs in the
same socket are in nohz_full mode. We can observe huge time burn in the
loop for seaching nearest busy housekeeper cpu by ftrace.

  2)               |                        get_nohz_timer_target() {
  2)   0.240 us    |                          housekeeping_test_cpu();
  2)   0.458 us    |                          housekeeping_test_cpu();

  ...

  2)   0.292 us    |                          housekeeping_test_cpu();
  2)   0.240 us    |                          housekeeping_test_cpu();
  2)   0.227 us    |                          housekeeping_any_cpu();
  2) + 43.460 us   |                        }

This patch optimizes the searching logic by finding a nearest housekeeper
CPU in the housekeeping cpumask, it can minimize the worst searching time
from ~44us to < 10us in my testing. In addition, the last iterated busy
housekeeper can become a random candidate while current CPU is a better
fallback if it is a housekeeper.

Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/1578876627-11938-1-git-send-email-wanpengli@tencent.com
2020-01-28 21:36:57 +01:00
Qais Yousef
b562d14064 sched/uclamp: Reject negative values in cpu_uclamp_write()
The check to ensure that the new written value into cpu.uclamp.{min,max}
is within range, [0:100], wasn't working because of the signed
comparison

 7301                 if (req.percent > UCLAMP_PERCENT_SCALE) {
 7302                         req.ret = -ERANGE;
 7303                         return req;
 7304                 }

	# echo -1 > cpu.uclamp.min
	# cat cpu.uclamp.min
	42949671.96

Cast req.percent into u64 to force the comparison to be unsigned and
work as intended in capacity_from_percent().

	# echo -1 > cpu.uclamp.min
	sh: write error: Numerical result out of range

Fixes: 2480c09313 ("sched/uclamp: Extend CPU's cgroup controller")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200114210947.14083-1-qais.yousef@arm.com
2020-01-28 21:36:56 +01:00
Mel Gorman
b396f52326 sched/fair: Allow a small load imbalance between low utilisation SD_NUMA domains
The CPU load balancer balances between different domains to spread load
and strives to have equal balance everywhere. Communicating tasks can
migrate so they are topologically close to each other but these decisions
are independent. On a lightly loaded NUMA machine, two communicating tasks
pulled together at wakeup time can be pushed apart by the load balancer.
In isolation, the load balancer decision is fine but it ignores the tasks
data locality and the wakeup/LB paths continually conflict. NUMA balancing
is also a factor but it also simply conflicts with the load balancer.

This patch allows a fixed degree of imbalance of two tasks to exist
between NUMA domains regardless of utilisation levels. In many cases,
this prevents communicating tasks being pulled apart. It was evaluated
whether the imbalance should be scaled to the domain size. However, no
additional benefit was measured across a range of workloads and machines
and scaling adds the risk that lower domains have to be rebalanced. While
this could change again in the future, such a change should specify the
use case and benefit.

The most obvious impact is on netperf TCP_STREAM -- two simple
communicating tasks with some softirq offload depending on the
transmission rate.

 2-socket Haswell machine 48 core, HT enabled
 netperf-tcp -- mmtests config config-network-netperf-unbound
			      baseline              lbnuma-v3
 Hmean     64         568.73 (   0.00%)      577.56 *   1.55%*
 Hmean     128       1089.98 (   0.00%)     1128.06 *   3.49%*
 Hmean     256       2061.72 (   0.00%)     2104.39 *   2.07%*
 Hmean     1024      7254.27 (   0.00%)     7557.52 *   4.18%*
 Hmean     2048     11729.20 (   0.00%)    13350.67 *  13.82%*
 Hmean     3312     15309.08 (   0.00%)    18058.95 *  17.96%*
 Hmean     4096     17338.75 (   0.00%)    20483.66 *  18.14%*
 Hmean     8192     25047.12 (   0.00%)    27806.84 *  11.02%*
 Hmean     16384    27359.55 (   0.00%)    33071.88 *  20.88%*
 Stddev    64           2.16 (   0.00%)        2.02 (   6.53%)
 Stddev    128          2.31 (   0.00%)        2.19 (   5.05%)
 Stddev    256         11.88 (   0.00%)        3.22 (  72.88%)
 Stddev    1024        23.68 (   0.00%)        7.24 (  69.43%)
 Stddev    2048        79.46 (   0.00%)       71.49 (  10.03%)
 Stddev    3312        26.71 (   0.00%)       57.80 (-116.41%)
 Stddev    4096       185.57 (   0.00%)       96.15 (  48.19%)
 Stddev    8192       245.80 (   0.00%)      100.73 (  59.02%)
 Stddev    16384      207.31 (   0.00%)      141.65 (  31.67%)

In this case, there was a sizable improvement to performance and
a general reduction in variance. However, this is not univeral.
For most machines, the impact was roughly a 3% performance gain.

 Ops NUMA base-page range updates       19796.00         292.00
 Ops NUMA PTE updates                   19796.00         292.00
 Ops NUMA PMD updates                       0.00           0.00
 Ops NUMA hint faults                   16113.00         143.00
 Ops NUMA hint local faults %            8407.00         142.00
 Ops NUMA hint local percent               52.18          99.30
 Ops NUMA pages migrated                 4244.00           1.00

Without the patch, only 52.18% of sampled accesses are local.  In an
earlier changelog, 100% of sampled accesses are local and indeed on
most machines, this was still the case. In this specific case, the
local sampled rates was 99.3% but note the "base-page range updates"
and "PTE updates".  The activity with the patch is negligible as were
the number of faults. The small number of pages migrated were related to
shared libraries.  A 2-socket Broadwell showed better results on average
but are not presented for brevity as the performance was similar except
it showed 100% of the sampled NUMA hints were local. The patch holds up
for a 4-socket Haswell, an AMD EPYC and AMD Epyc 2 machine.

For dbench, the impact depends on the filesystem used and the number of
clients. On XFS, there is little difference as the clients typically
communicate with workqueues which have a separate class of scheduler
problem at the moment. For ext4, performance is generally better,
particularly for small numbers of clients as NUMA balancing activity is
negligible with the patch applied.

A more interesting example is the Facebook schbench which uses a
number of messaging threads to communicate with worker threads. In this
configuration, one messaging thread is used per NUMA node and the number of
worker threads is varied. The 50, 75, 90, 95, 99, 99.5 and 99.9 percentiles
for response latency is then reported.

 Lat 50.00th-qrtle-1        44.00 (   0.00%)       37.00 (  15.91%)
 Lat 75.00th-qrtle-1        53.00 (   0.00%)       41.00 (  22.64%)
 Lat 90.00th-qrtle-1        57.00 (   0.00%)       42.00 (  26.32%)
 Lat 95.00th-qrtle-1        63.00 (   0.00%)       43.00 (  31.75%)
 Lat 99.00th-qrtle-1        76.00 (   0.00%)       51.00 (  32.89%)
 Lat 99.50th-qrtle-1        89.00 (   0.00%)       52.00 (  41.57%)
 Lat 99.90th-qrtle-1        98.00 (   0.00%)       55.00 (  43.88%)
 Lat 50.00th-qrtle-2        42.00 (   0.00%)       42.00 (   0.00%)
 Lat 75.00th-qrtle-2        48.00 (   0.00%)       47.00 (   2.08%)
 Lat 90.00th-qrtle-2        53.00 (   0.00%)       52.00 (   1.89%)
 Lat 95.00th-qrtle-2        55.00 (   0.00%)       53.00 (   3.64%)
 Lat 99.00th-qrtle-2        62.00 (   0.00%)       60.00 (   3.23%)
 Lat 99.50th-qrtle-2        63.00 (   0.00%)       63.00 (   0.00%)
 Lat 99.90th-qrtle-2        68.00 (   0.00%)       66.00 (   2.94%

For higher worker threads, the differences become negligible but it's
interesting to note the difference in wakeup latency at low utilisation
and mpstat confirms that activity was almost all on one node until
the number of worker threads increase.

Hackbench generally showed neutral results across a range of machines.
This is different to earlier versions of the patch which allowed imbalances
for higher degrees of utilisation. perf bench pipe showed negligible
differences in overall performance as the differences are very close to
the noise.

An earlier prototype of the patch showed major regressions for NAS C-class
when running with only half of the available CPUs -- 20-30% performance
hits were measured at the time. With this version of the patch, the impact
is negligible with small gains/losses within the noise measured. This is
because the number of threads far exceeds the small imbalance the aptch
cares about. Similarly, there were report of regressions for the autonuma
benchmark against earlier versions but again, normal load balancing now
applies for that workload.

In general, the patch simply seeks to avoid unnecessary cross-node
migrations in the basic case where imbalances are very small.  For low
utilisation communicating workloads, this patch generally behaves better
with less NUMA balancing activity. For high utilisation, there is no
change in behaviour.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Phil Auld <pauld@redhat.com>
Tested-by: Phil Auld <pauld@redhat.com>
Link: https://lkml.kernel.org/r/20200114101319.GO3466@techsingularity.net
2020-01-28 21:36:55 +01:00
Peter Zijlstra (Intel)
ebc0f83c78 timers/nohz: Update NOHZ load in remote tick
The way loadavg is tracked during nohz only pays attention to the load
upon entering nohz.  This can be particularly noticeable if full nohz is
entered while non-idle, and then the cpu goes idle and stays that way for
a long time.

Use the remote tick to ensure that full nohz cpus report their deltas
within a reasonable time.

[ swood: Added changelog and removed recheck of stopped tick. ]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Scott Wood <swood@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/1578736419-14628-3-git-send-email-swood@redhat.com
2020-01-28 21:36:44 +01:00
Scott Wood
488603b815 sched/core: Don't skip remote tick for idle CPUs
This will be used in the next patch to get a loadavg update from
nohz cpus.  The delta check is skipped because idle_sched_class
doesn't update se.exec_start.

Signed-off-by: Scott Wood <swood@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/1578736419-14628-2-git-send-email-swood@redhat.com
2020-01-28 21:36:16 +01:00
Song Liu
07c5972951 perf/cgroups: Install cgroup events to correct cpuctx
cgroup events are always installed in the cpuctx. However, when it is not
installed via IPI, list_update_cgroup_event() adds it to cpuctx of current
CPU, which triggers list corruption:

  [] list_add double add: new=ffff888ff7cf0db0, prev=ffff888ff7ce82f0, next=ffff888ff7cf0db0.

To reproduce this, we can simply run:

  # perf stat -e cs -a &
  # perf stat -e cs -G anycgroup

Fix this by installing it to cpuctx that contains event->ctx, and the
proper cgrp_cpuctx_list.

Fixes: db0503e4f6 ("perf/core: Optimize perf_install_in_event()")
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200122195027.2112449-1-songliubraving@fb.com
2020-01-28 21:20:19 +01:00
Song Liu
003461559e perf/core: Fix mlock accounting in perf_mmap()
Decreasing sysctl_perf_event_mlock between two consecutive perf_mmap()s of
a perf ring buffer may lead to an integer underflow in locked memory
accounting. This may lead to the undesired behaviors, such as failures in
BPF map creation.

Address this by adjusting the accounting logic to take into account the
possibility that the amount of already locked memory may exceed the
current limit.

Fixes: c4b7547974 ("perf/core: Make the mlock accounting simple again")
Suggested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lkml.kernel.org/r/20200123181146.2238074-1-songliubraving@fb.com
2020-01-28 21:20:18 +01:00
Linus Torvalds
c677124e63 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "These were the main changes in this cycle:

   - More -rt motivated separation of CONFIG_PREEMPT and
     CONFIG_PREEMPTION.

   - Add more low level scheduling topology sanity checks and warnings
     to filter out nonsensical topologies that break scheduling.

   - Extend uclamp constraints to influence wakeup CPU placement

   - Make the RT scheduler more aware of asymmetric topologies and CPU
     capacities, via uclamp metrics, if CONFIG_UCLAMP_TASK=y

   - Make idle CPU selection more consistent

   - Various fixes, smaller cleanups, updates and enhancements - please
     see the git log for details"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits)
  sched/fair: Define sched_idle_cpu() only for SMP configurations
  sched/topology: Assert non-NUMA topology masks don't (partially) overlap
  idle: fix spelling mistake "iterrupts" -> "interrupts"
  sched/fair: Remove redundant call to cpufreq_update_util()
  sched/psi: create /proc/pressure and /proc/pressure/{io|memory|cpu} only when psi enabled
  sched/fair: Fix sgc->{min,max}_capacity calculation for SD_OVERLAP
  sched/fair: calculate delta runnable load only when it's needed
  sched/cputime: move rq parameter in irqtime_account_process_tick
  stop_machine: Make stop_cpus() static
  sched/debug: Reset watchdog on all CPUs while processing sysrq-t
  sched/core: Fix size of rq::uclamp initialization
  sched/uclamp: Fix a bug in propagating uclamp value in new cgroups
  sched/fair: Load balance aggressively for SCHED_IDLE CPUs
  sched/fair : Improve update_sd_pick_busiest for spare capacity case
  watchdog: Remove soft_lockup_hrtimer_cnt and related code
  sched/rt: Make RT capacity-aware
  sched/fair: Make EAS wakeup placement consider uclamp restrictions
  sched/fair: Make task_fits_capacity() consider uclamp restrictions
  sched/uclamp: Rename uclamp_util_with() into uclamp_rq_util_with()
  sched/uclamp: Make uclamp util helpers use and return UL values
  ...
2020-01-28 10:07:09 -08:00
Linus Torvalds
c0e809e244 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
 "Kernel side changes:

   - Ftrace is one of the last W^X violators (after this only KLP is
     left). These patches move it over to the generic text_poke()
     interface and thereby get rid of this oddity. This requires a
     surprising amount of surgery, by Peter Zijlstra.

   - x86/AMD PMUs: add support for 'Large Increment per Cycle Events' to
     count certain types of events that have a special, quirky hw ABI
     (by Kim Phillips)

   - kprobes fixes by Masami Hiramatsu

  Lots of tooling updates as well, the following subcommands were
  updated: annotate/report/top, c2c, clang, record, report/top TUI,
  sched timehist, tests; plus updates were done to the gtk ui, libperf,
  headers and the parser"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
  perf/x86/amd: Add support for Large Increment per Cycle Events
  perf/x86/amd: Constrain Large Increment per Cycle events
  perf/x86/intel/rapl: Add Comet Lake support
  tracing: Initialize ret in syscall_enter_define_fields()
  perf header: Use last modification time for timestamp
  perf c2c: Fix return type for histogram sorting comparision functions
  perf beauty sockaddr: Fix augmented syscall format warning
  perf/ui/gtk: Fix gtk2 build
  perf ui gtk: Add missing zalloc object
  perf tools: Use %define api.pure full instead of %pure-parser
  libperf: Setup initial evlist::all_cpus value
  perf report: Fix no libunwind compiled warning break s390 issue
  perf tools: Support --prefix/--prefix-strip
  perf report: Clarify in help that --children is default
  tools build: Fix test-clang.cpp with Clang 8+
  perf clang: Fix build with Clang 9
  kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logic
  tools lib: Fix builds when glibc contains strlcpy()
  perf report/top: Make 'e' visible in the help and make it toggle showing callchains
  perf report/top: Do not offer annotation for symbols without samples
  ...
2020-01-28 09:44:15 -08:00
Linus Torvalds
2180f214f4 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
 "Just a handful of changes in this cycle: an ARM64 performance
  optimization, a comment fix and a debug output fix"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/osq: Use optimized spinning loop for arm64
  locking/qspinlock: Fix inaccessible URL of MCS lock paper
  locking/lockdep: Fix lockdep_stats indentation problem
2020-01-28 09:33:25 -08:00
Linus Torvalds
d99391ec2b Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "The RCU changes in this cycle were:
   - Expedited grace-period updates
   - kfree_rcu() updates
   - RCU list updates
   - Preemptible RCU updates
   - Torture-test updates
   - Miscellaneous fixes
   - Documentation updates"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (69 commits)
  rcu: Remove unused stop-machine #include
  powerpc: Remove comment about read_barrier_depends()
  .mailmap: Add entries for old paulmck@kernel.org addresses
  srcu: Apply *_ONCE() to ->srcu_last_gp_end
  rcu: Switch force_qs_rnp() to for_each_leaf_node_cpu_mask()
  rcu: Move rcu_{expedited,normal} definitions into rcupdate.h
  rcu: Move gp_state_names[] and gp_state_getname() to tree_stall.h
  rcu: Remove the declaration of call_rcu() in tree.h
  rcu: Fix tracepoint tracking RCU CPU kthread utilization
  rcu: Fix harmless omission of "CONFIG_" from #if condition
  rcu: Avoid tick_dep_set_cpu() misordering
  rcu: Provide wrappers for uses of ->rcu_read_lock_nesting
  rcu: Use READ_ONCE() for ->expmask in rcu_read_unlock_special()
  rcu: Clear ->rcu_read_unlock_special only once
  rcu: Clear .exp_hint only when deferred quiescent state has been reported
  rcu: Rename some instance of CONFIG_PREEMPTION to CONFIG_PREEMPT_RCU
  rcu: Remove kfree_call_rcu_nobatch()
  rcu: Remove kfree_rcu() special casing and lazy-callback handling
  rcu: Add support for debug_objects debugging for kfree_rcu()
  rcu: Add multiple in-flight batches of kfree_rcu() work
  ...
2020-01-28 08:46:13 -08:00
Sebastian Andrzej Siewior
25a3a15417 smp: Remove superfluous cond_func check in smp_call_function_many_cond()
It was requested to remove the cond_func check but the follow up patch was
overlooked. Remove it now.

Fixes: 67719ef25e ("smp: Add a smp_cond_func_t argument to smp_call_function_many()")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200127083915.434tdkztorkklpdu@linutronix.de
2020-01-28 15:43:00 +01:00
Mike Christie
8d19f1c8e1
prctl: PR_{G,S}ET_IO_FLUSHER to support controlling memory reclaim
There are several storage drivers like dm-multipath, iscsi, tcmu-runner,
amd nbd that have userspace components that can run in the IO path. For
example, iscsi and nbd's userspace deamons may need to recreate a socket
and/or send IO on it, and dm-multipath's daemon multipathd may need to
send SG IO or read/write IO to figure out the state of paths and re-set
them up.

In the kernel these drivers have access to GFP_NOIO/GFP_NOFS and the
memalloc_*_save/restore functions to control the allocation behavior,
but for userspace we would end up hitting an allocation that ended up
writing data back to the same device we are trying to allocate for.
The device is then in a state of deadlock, because to execute IO the
device needs to allocate memory, but to allocate memory the memory
layers want execute IO to the device.

Here is an example with nbd using a local userspace daemon that performs
network IO to a remote server. We are using XFS on top of the nbd device,
but it can happen with any FS or other modules layered on top of the nbd
device that can write out data to free memory.  Here a nbd daemon helper
thread, msgr-worker-1, is performing a write/sendmsg on a socket to execute
a request. This kicks off a reclaim operation which results in a WRITE to
the nbd device and the nbd thread calling back into the mm layer.

[ 1626.609191] msgr-worker-1   D    0  1026      1 0x00004000
[ 1626.609193] Call Trace:
[ 1626.609195]  ? __schedule+0x29b/0x630
[ 1626.609197]  ? wait_for_completion+0xe0/0x170
[ 1626.609198]  schedule+0x30/0xb0
[ 1626.609200]  schedule_timeout+0x1f6/0x2f0
[ 1626.609202]  ? blk_finish_plug+0x21/0x2e
[ 1626.609204]  ? _xfs_buf_ioapply+0x2e6/0x410
[ 1626.609206]  ? wait_for_completion+0xe0/0x170
[ 1626.609208]  wait_for_completion+0x108/0x170
[ 1626.609210]  ? wake_up_q+0x70/0x70
[ 1626.609212]  ? __xfs_buf_submit+0x12e/0x250
[ 1626.609214]  ? xfs_bwrite+0x25/0x60
[ 1626.609215]  xfs_buf_iowait+0x22/0xf0
[ 1626.609218]  __xfs_buf_submit+0x12e/0x250
[ 1626.609220]  xfs_bwrite+0x25/0x60
[ 1626.609222]  xfs_reclaim_inode+0x2e8/0x310
[ 1626.609224]  xfs_reclaim_inodes_ag+0x1b6/0x300
[ 1626.609227]  xfs_reclaim_inodes_nr+0x31/0x40
[ 1626.609228]  super_cache_scan+0x152/0x1a0
[ 1626.609231]  do_shrink_slab+0x12c/0x2d0
[ 1626.609233]  shrink_slab+0x9c/0x2a0
[ 1626.609235]  shrink_node+0xd7/0x470
[ 1626.609237]  do_try_to_free_pages+0xbf/0x380
[ 1626.609240]  try_to_free_pages+0xd9/0x1f0
[ 1626.609245]  __alloc_pages_slowpath+0x3a4/0xd30
[ 1626.609251]  ? ___slab_alloc+0x238/0x560
[ 1626.609254]  __alloc_pages_nodemask+0x30c/0x350
[ 1626.609259]  skb_page_frag_refill+0x97/0xd0
[ 1626.609274]  sk_page_frag_refill+0x1d/0x80
[ 1626.609279]  tcp_sendmsg_locked+0x2bb/0xdd0
[ 1626.609304]  tcp_sendmsg+0x27/0x40
[ 1626.609307]  sock_sendmsg+0x54/0x60
[ 1626.609308]  ___sys_sendmsg+0x29f/0x320
[ 1626.609313]  ? sock_poll+0x66/0xb0
[ 1626.609318]  ? ep_item_poll.isra.15+0x40/0xc0
[ 1626.609320]  ? ep_send_events_proc+0xe6/0x230
[ 1626.609322]  ? hrtimer_try_to_cancel+0x54/0xf0
[ 1626.609324]  ? ep_read_events_proc+0xc0/0xc0
[ 1626.609326]  ? _raw_write_unlock_irq+0xa/0x20
[ 1626.609327]  ? ep_scan_ready_list.constprop.19+0x218/0x230
[ 1626.609329]  ? __hrtimer_init+0xb0/0xb0
[ 1626.609331]  ? _raw_spin_unlock_irq+0xa/0x20
[ 1626.609334]  ? ep_poll+0x26c/0x4a0
[ 1626.609337]  ? tcp_tsq_write.part.54+0xa0/0xa0
[ 1626.609339]  ? release_sock+0x43/0x90
[ 1626.609341]  ? _raw_spin_unlock_bh+0xa/0x20
[ 1626.609342]  __sys_sendmsg+0x47/0x80
[ 1626.609347]  do_syscall_64+0x5f/0x1c0
[ 1626.609349]  ? prepare_exit_to_usermode+0x75/0xa0
[ 1626.609351]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

This patch adds a new prctl command that daemons can use after they have
done their initial setup, and before they start to do allocations that
are in the IO path. It sets the PF_MEMALLOC_NOIO and PF_LESS_THROTTLE
flags so both userspace block and FS threads can use it to avoid the
allocation recursion and try to prevent from being throttled while
writing out data to free up memory.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Masato Suzuki <masato.suzuki@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Link: https://lore.kernel.org/r/20191112001900.9206-1-mchristi@redhat.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-01-28 10:09:51 +01:00
Ingo Molnar
0cc4bd8f70 Merge branch 'core/kprobes' into perf/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-28 07:59:05 +01:00
Linus Torvalds
3d3b44a61a The interrupt departement provides:
- A mechanism to shield isolated tasks from managed interrupts:
 
    The affinity of managed interrupts is completely controlled by the
    kernel and user space has no influence on them. The reason is that
    the automatically assigned affinity correlates to the multi-queue
    CPU handling of block devices.
 
    If the generated affinity mask spaws both housekeeping and isolated CPUs
    the interrupt could be routed to an isolated CPU which would then be
    disturbed by I/O submitted by a housekeeping CPU.
 
    The new mechamism ensures that as long as one housekeeping CPU is online
    in the assigned affinity mask the interrupt is routed to a housekeeping
    CPU.
 
    If there is no online housekeeping CPU in the affinity mask, then the
    interrupt is routed to an isolated CPU to keep the device queue intact,
    but unless the isolated CPU submits I/O by itself these interrupts are
    not raised.
 
  - A small addon to the device tree irqdomain core code to avoid
    duplication in irq chip drivers
 
  - Conversion of the SiFive PLIC to hierarchical domains
 
  - The usual pile of new irq chip drivers: SiFive GPIO, Aspeed SCI, NXP
    INTMUX, Meson A1 GPIO
 
  - The first cut of support for the new ARM GICv4.1
 
  - The usual pile of fixes and improvements in core and driver code
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Merge tag 'irq-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "The interrupt departement provides:

   - A mechanism to shield isolated tasks from managed interrupts:

     The affinity of managed interrupts is completely controlled by the
     kernel and user space has no influence on them. The reason is that
     the automatically assigned affinity correlates to the multi-queue
     CPU handling of block devices.

     If the generated affinity mask spaws both housekeeping and isolated
     CPUs the interrupt could be routed to an isolated CPU which would
     then be disturbed by I/O submitted by a housekeeping CPU.

     The new mechamism ensures that as long as one housekeeping CPU is
     online in the assigned affinity mask the interrupt is routed to a
     housekeeping CPU.

     If there is no online housekeeping CPU in the affinity mask, then
     the interrupt is routed to an isolated CPU to keep the device queue
     intact, but unless the isolated CPU submits I/O by itself these
     interrupts are not raised.

   - A small addon to the device tree irqdomain core code to avoid
     duplication in irq chip drivers

   - Conversion of the SiFive PLIC to hierarchical domains

   - The usual pile of new irq chip drivers: SiFive GPIO, Aspeed SCI,
     NXP INTMUX, Meson A1 GPIO

   - The first cut of support for the new ARM GICv4.1

   - The usual pile of fixes and improvements in core and driver code"

* tag 'irq-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  genirq, sched/isolation: Isolate from handling managed interrupts
  irqchip/gic-v4.1: Allow direct invalidation of VLPIs
  irqchip/gic-v4.1: Suppress per-VLPI doorbell
  irqchip/gic-v4.1: Add VPE INVALL callback
  irqchip/gic-v4.1: Add VPE eviction callback
  irqchip/gic-v4.1: Add VPE residency callback
  irqchip/gic-v4.1: Add mask/unmask doorbell callbacks
  irqchip/gic-v4.1: Plumb skeletal VPE irqchip
  irqchip/gic-v4.1: Implement the v4.1 flavour of VMOVP
  irqchip/gic-v4.1: Don't use the VPE proxy if RVPEID is set
  irqchip/gic-v4.1: Implement the v4.1 flavour of VMAPP
  irqchip/gic-v4.1: VPE table (aka GICR_VPROPBASER) allocation
  irqchip/gic-v3: Add GICv4.1 VPEID size discovery
  irqchip/gic-v3: Detect GICv4.1 supporting RVPEID
  irqchip/gic-v3-its: Fix get_vlpi_map() breakage with doorbells
  irqdomain: Fix a memory leak in irq_domain_push_irq()
  irqchip: Add NXP INTMUX interrupt multiplexer support
  dt-bindings: interrupt-controller: Add binding for NXP INTMUX interrupt multiplexer
  irqchip: Define EXYNOS_IRQ_COMBINER
  irqchip/meson-gpio: Add support for meson a1 SoCs
  ...
2020-01-27 17:22:21 -08:00
Linus Torvalds
ab67f60025 A small set of SMP core code changes:
- Rework the smp function call core code to avoid the allocation of an
    additional cpumask.
 
  - Remove the not longer required GFP argument from on_each_cpu_cond() and
    on_each_cpu_cond_mask() and fixup the callers.
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Merge tag 'smp-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core SMP updates from Thomas Gleixner:
 "A small set of SMP core code changes:

   - Rework the smp function call core code to avoid the allocation of
     an additional cpumask

   - Remove the not longer required GFP argument from on_each_cpu_cond()
     and on_each_cpu_cond_mask() and fixup the callers"

* tag 'smp-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp: Remove allocation mask from on_each_cpu_cond.*()
  smp: Add a smp_cond_func_t argument to smp_call_function_many()
  smp: Use smp_cond_func_t as type for the conditional function
2020-01-27 17:04:51 -08:00
Linus Torvalds
e279160f49 The timekeeping and timers departement provides:
- Time namespace support:
 
     If a container migrates from one host to another then it expects that
     clocks based on MONOTONIC and BOOTTIME are not subject to
     disruption. Due to different boot time and non-suspended runtime these
     clocks can differ significantly on two hosts, in the worst case time
     goes backwards which is a violation of the POSIX requirements.
 
     The time namespace addresses this problem. It allows to set offsets for
     clock MONOTONIC and BOOTTIME once after creation and before tasks are
     associated with the namespace. These offsets are taken into account by
     timers and timekeeping including the VDSO.
 
     Offsets for wall clock based clocks (REALTIME/TAI) are not provided by
     this mechanism. While in theory possible, the overhead and code
     complexity would be immense and not justified by the esoteric potential
     use cases which were discussed at Plumbers '18.
 
     The overhead for tasks in the root namespace (host time offsets = 0) is
     in the noise and great effort was made to ensure that especially in the
     VDSO. If time namespace is disabled in the kernel configuration the
     code is compiled out.
 
     Kudos to Andrei Vagin and Dmitry Sofanov who implemented this feature
     and kept on for more than a year addressing review comments, finding
     better solutions. A pleasant experience.
 
   - Overhaul of the alarmtimer device dependency handling to ensure that
     the init/suspend/resume ordering is correct.
 
   - A new clocksource/event driver for Microchip PIT64
 
   - Suspend/resume support for the Hyper-V clocksource
 
   - The usual pile of fixes, updates and improvements mostly in the
     driver code.
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Merge tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "The timekeeping and timers departement provides:

   - Time namespace support:

     If a container migrates from one host to another then it expects
     that clocks based on MONOTONIC and BOOTTIME are not subject to
     disruption. Due to different boot time and non-suspended runtime
     these clocks can differ significantly on two hosts, in the worst
     case time goes backwards which is a violation of the POSIX
     requirements.

     The time namespace addresses this problem. It allows to set offsets
     for clock MONOTONIC and BOOTTIME once after creation and before
     tasks are associated with the namespace. These offsets are taken
     into account by timers and timekeeping including the VDSO.

     Offsets for wall clock based clocks (REALTIME/TAI) are not provided
     by this mechanism. While in theory possible, the overhead and code
     complexity would be immense and not justified by the esoteric
     potential use cases which were discussed at Plumbers '18.

     The overhead for tasks in the root namespace (ie where host time
     offsets = 0) is in the noise and great effort was made to ensure
     that especially in the VDSO. If time namespace is disabled in the
     kernel configuration the code is compiled out.

     Kudos to Andrei Vagin and Dmitry Sofanov who implemented this
     feature and kept on for more than a year addressing review
     comments, finding better solutions. A pleasant experience.

   - Overhaul of the alarmtimer device dependency handling to ensure
     that the init/suspend/resume ordering is correct.

   - A new clocksource/event driver for Microchip PIT64

   - Suspend/resume support for the Hyper-V clocksource

   - The usual pile of fixes, updates and improvements mostly in the
     driver code"

* tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  alarmtimer: Make alarmtimer_get_rtcdev() a stub when CONFIG_RTC_CLASS=n
  alarmtimer: Use wakeup source from alarmtimer platform device
  alarmtimer: Make alarmtimer platform device child of RTC device
  alarmtimer: Update alarmtimer_get_rtcdev() docs to reflect reality
  hrtimer: Add missing sparse annotation for __run_timer()
  lib/vdso: Only read hrtimer_res when needed in __cvdso_clock_getres()
  MIPS: vdso: Define BUILD_VDSO32 when building a 32bit kernel
  clocksource/drivers/hyper-v: Set TSC clocksource as default w/ InvariantTSC
  clocksource/drivers/hyper-v: Untangle stimers and timesync from clocksources
  clocksource/drivers/timer-microchip-pit64b: Fix sparse warning
  clocksource/drivers/exynos_mct: Rename Exynos to lowercase
  clocksource/drivers/timer-ti-dm: Fix uninitialized pointer access
  clocksource/drivers/timer-ti-dm: Switch to platform_get_irq
  clocksource/drivers/timer-ti-dm: Convert to devm_platform_ioremap_resource
  clocksource/drivers/em_sti: Fix variable declaration in em_sti_probe
  clocksource/drivers/em_sti: Convert to devm_platform_ioremap_resource
  clocksource/drivers/bcm2835_timer: Fix memory leak of timer
  clocksource/drivers/cadence-ttc: Use ttc driver as platform driver
  clocksource/drivers/timer-microchip-pit64b: Add Microchip PIT64B support
  clocksource/drivers/hyper-v: Reserve PAGE_SIZE space for tsc page
  ...
2020-01-27 16:47:05 -08:00
Linus Torvalds
b11c89a158 A set of watchdog/softlockup related improvements:
- Enforce that the watchdog timestamp is always valid on boot. The
    original implementation caused a watchdog disabled gap of one second in
    the boot process due to truncation of the underlying sched clock. The
    sched clock is divided by 1e9 to convert nanoseconds to seconds. So for
    the first second of the boot process the result is 0 which is at the
    same time the indicator to disable the watchdog. The trivial fix is to
    change the disabled indicator to ULONG_MAX.
 
  - Two cleanup patches removing unused and redundant code which got
    forgotten to be cleaned up in previous changes.
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Merge tag 'core-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull watchdog updates from Thomas Gleixner:
 "A set of watchdog/softlockup related improvements:

   - Enforce that the watchdog timestamp is always valid on boot. The
     original implementation caused a watchdog disabled gap of one
     second in the boot process due to truncation of the underlying
     sched clock.

     The sched clock is divided by 1e9 to convert nanoseconds to
     seconds. So for the first second of the boot process the result is
     0 which is at the same time the indicator to disable the watchdog.

     The trivial fix is to change the disabled indicator to ULONG_MAX.

   - Two cleanup patches removing unused and redundant code which got
     forgotten to be cleaned up in previous changes"

* tag 'core-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  watchdog/softlockup: Enforce that timestamp is valid on boot
  watchdog/softlockup: Remove obsolete check of last reported task
  watchdog: Remove soft_lockup_hrtimer_cnt and related code
2020-01-27 16:42:11 -08:00
Linus Torvalds
a56c41e5d7 Two fixes for the generic VDSO code which missed 5.5:
- Make the update to the coarse timekeeper unconditional. This is required
    because the coarse timekeeper interfaces in the VDSO do not depend on a
    VDSO capable clocksource. If the system does not have a VDSO capable
    clocksource and the update is depending on the VDSO capable clocksource,
    the coarse VDSO interfaces would operate on stale data forever.
 
  - Invert the logic of __arch_update_vdso_data() to avoid further head
    scratching. Tripped over this several times while analyzing the update
    problem above.
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Merge tag 'timers-urgent-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Thomas Gleixner:
 "Two fixes for the generic VDSO code which missed 5.5:

   - Make the update to the coarse timekeeper unconditional.

     This is required because the coarse timekeeper interfaces in the
     VDSO do not depend on a VDSO capable clocksource. If the system
     does not have a VDSO capable clocksource and the update is
     depending on the VDSO capable clocksource, the coarse VDSO
     interfaces would operate on stale data forever.

   - Invert the logic of __arch_update_vdso_data() to avoid further head
     scratching.

     Tripped over this several times while analyzing the update problem
     above"

* tag 'timers-urgent-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lib/vdso: Update coarse timekeeper unconditionally
  lib/vdso: Make __arch_update_vdso_data() logic understandable
2020-01-27 16:37:40 -08:00
Linus Torvalds
07e309a972 audit/stable-5.6 PR 20200127
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Merge tag 'audit-pr-20200127' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

Pull audit update from Paul Moore:
 "One small audit patch for the Linux v5.6 merge window, and
  unsurprisingly it passes our test suite with flying colors"

* tag 'audit-pr-20200127' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: Add __rcu annotation to RCU pointer
2020-01-27 15:35:50 -08:00
Linus Torvalds
03aa8c8cfa Merge branch 'for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:

 - cgroup2 interface for hugetlb controller. I think this was the last
   remaining bit which was missing from cgroup2

 - fixes for race and a spurious warning in threaded cgroup handling

 - other minor changes

* 'for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  iocost: Fix iocost_monitor.py due to helper type mismatch
  cgroup: Prevent double killing of css when enabling threaded cgroup
  cgroup: fix function name in comment
  mm: hugetlb controller for cgroups v2
2020-01-27 15:18:25 -08:00
Linus Torvalds
16d06120d7 Merge branch 'for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo:
 "Just a couple tracepoint patches"

* 'for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: remove workqueue_work event class
  workqueue: add worker function to workqueue_execute_end tracepoint
2020-01-27 15:16:52 -08:00
Linus Torvalds
6d277aca48 Power management updates for 5.6-rc1
- Update the ACPI processor driver in order to export
    acpi_processor_evaluate_cst() to the code outside of it, add
    ACPI support to the intel_idle driver based on that and clean
    up that driver somewhat (Rafael Wysocki).
 
  - Add an admin guide document for the intel_idle driver (Rafael
    Wysocki).
 
  - Clean up cpuidle core and drivers, enable compilation testing
    for some of them (Benjamin Gaignard, Krzysztof Kozlowski, Rafael
    Wysocki, Yangtao Li).
 
  - Fix reference counting of OPP (operating performance points) table
    structures (Viresh Kumar).
 
  - Add support for CPR (Core Power Reduction) to the AVS (Adaptive
    Voltage Scaling) subsystem (Niklas Cassel, Colin Ian King,
    YueHaibing).
 
  - Add support for TigerLake Mobile and JasperLake to the Intel RAPL
    power capping driver (Zhang Rui).
 
  - Update cpufreq drivers:
 
    * Add i.MX8MP support to imx-cpufreq-dt (Anson Huang).
 
    * Fix usage of a macro in loongson2_cpufreq (Alexandre Oliva).
 
    * Fix cpufreq policy reference counting issues in s3c and
      brcmstb-avs (chenqiwu).
 
    * Fix ACPI table reference counting issue and HiSilicon quirk
      handling in the CPPC driver (Hanjun Guo).
 
    * Clean up spelling mistake in intel_pstate (Harry Pan).
 
    * Convert the kirkwood and tegra186 drivers to using
      devm_platform_ioremap_resource() (Yangtao Li).
 
  - Update devfreq core:
 
    * Add 'name' sysfs attribute for devfreq devices (Chanwoo Choi).
 
    * Clean up the handing of transition statistics and allow them
      to be reset by writing 0 to the 'trans_stat' devfreq device
      attribute in sysfs (Kamil Konieczny).
 
    * Add 'devfreq_summary' to debugfs (Chanwoo Choi).
 
    * Clean up kerneldoc comments and Kconfig indentation (Krzysztof
      Kozlowski, Randy Dunlap).
 
  - Update devfreq drivers:
 
    * Add dynamic scaling for the imx8m DDR controller and clean up
      imx8m-ddrc (Leonard Crestez, YueHaibing).
 
    * Fix DT node reference counting and nitialization error code path
      in rk3399_dmc and add COMPILE_TEST and HAVE_ARM_SMCCC dependency
      for it (Chanwoo Choi, Yangtao Li).
 
    * Fix DT node reference counting in rockchip-dfi and make it use
      devm_platform_ioremap_resource() (Yangtao Li).
 
    * Fix excessive stack usage in exynos-ppmu (Arnd Bergmann).
 
    * Fix initialization error code paths in exynos-bus (Yangtao Li).
 
    * Clean up exynos-bus and exynos somewhat (Artur Świgoń, Krzysztof
      Kozlowski).
 
  - Add tracepoints for tracking usage_count updates unrelated to
    status changes in PM-runtime (Michał Mirosław).
 
  - Add sysfs attribute to control the "sync on suspend" behavior
    during system-wide suspend (Jonas Meurer).
 
  - Switch system-wide suspend tests over to 64-bit time (Alexandre
    Belloni).
 
  - Make wakeup sources statistics in debugfs cover deleted ones which
    used to be the case some time ago (zhuguangqing).
 
  - Clean up computations carried out during hibernation, update
    messages related to hibernation and fix a spelling mistake in one
    of them (Wen Yang, Luigi Semenzato, Colin Ian King).
 
  - Add mailmap entry for maintainer e-mail address that has not been
    functional for several years (Rafael Wysocki).
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Merge tag 'pm-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "These add ACPI support to the intel_idle driver along with an admin
  guide document for it, add support for CPR (Core Power Reduction) to
  the AVS (Adaptive Voltage Scaling) subsystem, add new hardware support
  in a few places, add some new sysfs attributes, debugfs files and
  tracepoints, fix bugs and clean up a bunch of things all over.

  Specifics:

   - Update the ACPI processor driver in order to export
     acpi_processor_evaluate_cst() to the code outside of it, add ACPI
     support to the intel_idle driver based on that and clean up that
     driver somewhat (Rafael Wysocki).

   - Add an admin guide document for the intel_idle driver (Rafael
     Wysocki).

   - Clean up cpuidle core and drivers, enable compilation testing for
     some of them (Benjamin Gaignard, Krzysztof Kozlowski, Rafael
     Wysocki, Yangtao Li).

   - Fix reference counting of OPP (operating performance points) table
     structures (Viresh Kumar).

   - Add support for CPR (Core Power Reduction) to the AVS (Adaptive
     Voltage Scaling) subsystem (Niklas Cassel, Colin Ian King,
     YueHaibing).

   - Add support for TigerLake Mobile and JasperLake to the Intel RAPL
     power capping driver (Zhang Rui).

   - Update cpufreq drivers:
      - Add i.MX8MP support to imx-cpufreq-dt (Anson Huang).
      - Fix usage of a macro in loongson2_cpufreq (Alexandre Oliva).
      - Fix cpufreq policy reference counting issues in s3c and
        brcmstb-avs (chenqiwu).
      - Fix ACPI table reference counting issue and HiSilicon quirk
        handling in the CPPC driver (Hanjun Guo).
      - Clean up spelling mistake in intel_pstate (Harry Pan).
      - Convert the kirkwood and tegra186 drivers to using
        devm_platform_ioremap_resource() (Yangtao Li).

   - Update devfreq core:
      - Add 'name' sysfs attribute for devfreq devices (Chanwoo Choi).
      - Clean up the handing of transition statistics and allow them to
        be reset by writing 0 to the 'trans_stat' devfreq device
        attribute in sysfs (Kamil Konieczny).
      - Add 'devfreq_summary' to debugfs (Chanwoo Choi).
      - Clean up kerneldoc comments and Kconfig indentation (Krzysztof
        Kozlowski, Randy Dunlap).

   - Update devfreq drivers:
      - Add dynamic scaling for the imx8m DDR controller and clean up
        imx8m-ddrc (Leonard Crestez, YueHaibing).
      - Fix DT node reference counting and nitialization error code path
        in rk3399_dmc and add COMPILE_TEST and HAVE_ARM_SMCCC dependency
        for it (Chanwoo Choi, Yangtao Li).
      - Fix DT node reference counting in rockchip-dfi and make it use
        devm_platform_ioremap_resource() (Yangtao Li).
      - Fix excessive stack usage in exynos-ppmu (Arnd Bergmann).
      - Fix initialization error code paths in exynos-bus (Yangtao Li).
      - Clean up exynos-bus and exynos somewhat (Artur Świgoń, Krzysztof
        Kozlowski).

   - Add tracepoints for tracking usage_count updates unrelated to
     status changes in PM-runtime (Michał Mirosław).

   - Add sysfs attribute to control the "sync on suspend" behavior
     during system-wide suspend (Jonas Meurer).

   - Switch system-wide suspend tests over to 64-bit time (Alexandre
     Belloni).

   - Make wakeup sources statistics in debugfs cover deleted ones which
     used to be the case some time ago (zhuguangqing).

   - Clean up computations carried out during hibernation, update
     messages related to hibernation and fix a spelling mistake in one
     of them (Wen Yang, Luigi Semenzato, Colin Ian King).

   - Add mailmap entry for maintainer e-mail address that has not been
     functional for several years (Rafael Wysocki)"

* tag 'pm-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (83 commits)
  cpufreq: loongson2_cpufreq: adjust cpufreq uses of LOONGSON_CHIPCFG
  intel_idle: Clean up irtl_2_usec()
  intel_idle: Move 3 functions closer to their callers
  intel_idle: Annotate initialization code and data structures
  intel_idle: Move and clean up intel_idle_cpuidle_devices_uninit()
  intel_idle: Rearrange intel_idle_cpuidle_driver_init()
  intel_idle: Clean up NULL pointer check in intel_idle_init()
  intel_idle: Fold intel_idle_probe() into intel_idle_init()
  intel_idle: Eliminate __setup_broadcast_timer()
  cpuidle: fix cpuidle_find_deepest_state() kerneldoc warnings
  cpuidle: sysfs: fix warnings when compiling with W=1
  cpuidle: coupled: fix warnings when compiling with W=1
  cpufreq: brcmstb-avs: fix imbalance of cpufreq policy refcount
  PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior
  PM / devfreq: Add debugfs support with devfreq_summary file
  Documentation: admin-guide: PM: Add intel_idle document
  cpuidle: arm: Enable compile testing for some of drivers
  PM-runtime: add tracepoints for usage_count changes
  cpufreq: intel_pstate: fix spelling mistake: "Whethet" -> "Whether"
  PM: hibernate: fix spelling mistake "shapshot" -> "snapshot"
  ...
2020-01-27 11:23:54 -08:00
Linus Torvalds
0238d3c753 arm64 updates for 5.6
- New architecture features
 	* Support for Armv8.5 E0PD, which benefits KASLR in the same way as
 	  KPTI but without the overhead. This allows KPTI to be disabled on
 	  CPUs that are not affected by Meltdown, even is KASLR is enabled.
 
 	* Initial support for the Armv8.5 RNG instructions, which claim to
 	  provide access to a high bandwidth, cryptographically secure hardware
 	  random number generator. As well as exposing these to userspace, we
 	  also use them as part of the KASLR seed and to seed the crng once
 	  all CPUs have come online.
 
 	* Advertise a bunch of new instructions to userspace, including support
 	  for Data Gathering Hint, Matrix Multiply and 16-bit floating point.
 
 - Kexec
 	* Cleanups in preparation for relocating with the MMU enabled
 	* Support for loading crash dump kernels with kexec_file_load()
 
 - Perf and PMU drivers
 	* Cleanups and non-critical fixes for a couple of system PMU drivers
 
 - FPU-less (aka broken) CPU support
 	* Considerable fixes to support CPUs without the FP/SIMD extensions,
 	  including their presence in heterogeneous systems. Good luck finding
 	  a 64-bit userspace that handles this.
 
 - Modern assembly function annotations
 	* Start migrating our use of ENTRY() and ENDPROC() over to the
 	  new-fangled SYM_{CODE,FUNC}_{START,END} macros, which are intended to
 	  aid debuggers
 
 - Kbuild
 	* Cleanup detection of LSE support in the assembler by introducing
 	  'as-instr'
 
 	* Remove compressed Image files when building clean targets
 
 - IP checksumming
 	* Implement optimised IPv4 checksumming routine when hardware offload
 	  is not in use. An IPv6 version is in the works, pending testing.
 
 - Hardware errata
 	* Work around Cortex-A55 erratum #1530923
 
 - Shadow call stack
 	* Work around some issues with Clang's integrated assembler not liking
 	  our perfectly reasonable assembly code
 
 	* Avoid allocating the X18 register, so that it can be used to hold the
 	  shadow call stack pointer in future
 
 - ACPI
 	* Fix ID count checking in IORT code. This may regress broken firmware
 	  that happened to work with the old implementation, in which case we'll
 	  have to revert it and try something else
 
 	* Fix DAIF corruption on return from GHES handler with pseudo-NMIs
 
 - Miscellaneous
 	* Whitelist some CPUs that are unaffected by Spectre-v2
 
 	* Reduce frequency of ASID rollover when KPTI is compiled in but
 	  inactive
 
 	* Reserve a couple of arch-specific PROT flags that are already used by
 	  Sparc and PowerPC and are planned for later use with BTI on arm64
 
 	* Preparatory cleanup of our entry assembly code in preparation for
 	  moving more of it into C later on
 
 	* Refactoring and cleanup
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "The changes are a real mixed bag this time around.

  The only scary looking one from the diffstat is the uapi change to
  asm-generic/mman-common.h, but this has been acked by Arnd and is
  actually just adding a pair of comments in an attempt to prevent
  allocation of some PROT values which tend to get used for
  arch-specific purposes. We'll be using them for Branch Target
  Identification (a CFI-like hardening feature), which is currently
  under review on the mailing list.

  New architecture features:

   - Support for Armv8.5 E0PD, which benefits KASLR in the same way as
     KPTI but without the overhead. This allows KPTI to be disabled on
     CPUs that are not affected by Meltdown, even is KASLR is enabled.

   - Initial support for the Armv8.5 RNG instructions, which claim to
     provide access to a high bandwidth, cryptographically secure
     hardware random number generator. As well as exposing these to
     userspace, we also use them as part of the KASLR seed and to seed
     the crng once all CPUs have come online.

   - Advertise a bunch of new instructions to userspace, including
     support for Data Gathering Hint, Matrix Multiply and 16-bit
     floating point.

  Kexec:

   - Cleanups in preparation for relocating with the MMU enabled

   - Support for loading crash dump kernels with kexec_file_load()

  Perf and PMU drivers:

   - Cleanups and non-critical fixes for a couple of system PMU drivers

  FPU-less (aka broken) CPU support:

   - Considerable fixes to support CPUs without the FP/SIMD extensions,
     including their presence in heterogeneous systems. Good luck
     finding a 64-bit userspace that handles this.

  Modern assembly function annotations:

   - Start migrating our use of ENTRY() and ENDPROC() over to the
     new-fangled SYM_{CODE,FUNC}_{START,END} macros, which are intended
     to aid debuggers

  Kbuild:

   - Cleanup detection of LSE support in the assembler by introducing
     'as-instr'

   - Remove compressed Image files when building clean targets

  IP checksumming:

   - Implement optimised IPv4 checksumming routine when hardware offload
     is not in use. An IPv6 version is in the works, pending testing.

  Hardware errata:

   - Work around Cortex-A55 erratum #1530923

  Shadow call stack:

   - Work around some issues with Clang's integrated assembler not
     liking our perfectly reasonable assembly code

   - Avoid allocating the X18 register, so that it can be used to hold
     the shadow call stack pointer in future

  ACPI:

   - Fix ID count checking in IORT code. This may regress broken
     firmware that happened to work with the old implementation, in
     which case we'll have to revert it and try something else

   - Fix DAIF corruption on return from GHES handler with pseudo-NMIs

  Miscellaneous:

   - Whitelist some CPUs that are unaffected by Spectre-v2

   - Reduce frequency of ASID rollover when KPTI is compiled in but
     inactive

   - Reserve a couple of arch-specific PROT flags that are already used
     by Sparc and PowerPC and are planned for later use with BTI on
     arm64

   - Preparatory cleanup of our entry assembly code in preparation for
     moving more of it into C later on

   - Refactoring and cleanup"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (73 commits)
  arm64: acpi: fix DAIF manipulation with pNMI
  arm64: kconfig: Fix alignment of E0PD help text
  arm64: Use v8.5-RNG entropy for KASLR seed
  arm64: Implement archrandom.h for ARMv8.5-RNG
  arm64: kbuild: remove compressed images on 'make ARCH=arm64 (dist)clean'
  arm64: entry: Avoid empty alternatives entries
  arm64: Kconfig: select HAVE_FUTEX_CMPXCHG
  arm64: csum: Fix pathological zero-length calls
  arm64: entry: cleanup sp_el0 manipulation
  arm64: entry: cleanup el0 svc handler naming
  arm64: entry: mark all entry code as notrace
  arm64: assembler: remove smp_dmb macro
  arm64: assembler: remove inherit_daif macro
  ACPI/IORT: Fix 'Number of IDs' handling in iort_id_map()
  mm: Reserve asm-generic prot flags 0x10 and 0x20 for arch use
  arm64: Use macros instead of hard-coded constants for MAIR_EL1
  arm64: Add KRYO{3,4}XX CPU cores to spectre-v2 safe list
  arm64: kernel: avoid x18 in __cpu_soft_restart
  arm64: kvm: stop treating register x18 as caller save
  arm64/lib: copy_page: avoid x18 register in assembler code
  ...
2020-01-27 08:58:19 -08:00
Steven Rostedt (VMware)
20279420ae tracing/kprobes: Have uname use __get_str() in print_fmt
Thomas Richter reported:

> Test case 66 'Use vfs_getname probe to get syscall args filenames'
> is broken on s390, but works on x86. The test case fails with:
>
>  [root@m35lp76 perf]# perf test -F 66
>  66: Use vfs_getname probe to get syscall args filenames
>            :Recording open file:
>  [ perf record: Woken up 1 times to write data ]
>  [ perf record: Captured and wrote 0.004 MB /tmp/__perf_test.perf.data.TCdYj\
> 	 (20 samples) ]
>  Looking at perf.data file for vfs_getname records for the file we touched:
>   FAILED!
>   [root@m35lp76 perf]#

The root cause was the print_fmt of the kprobe event that referenced the
"ustring"

> Setting up the kprobe event using perf command:
>
>  # ./perf probe "vfs_getname=getname_flags:72 pathname=filename:ustring"
>
> generates this format file:
>   [root@m35lp76 perf]# cat /sys/kernel/debug/tracing/events/probe/\
> 	  vfs_getname/format
>   name: vfs_getname
>   ID: 1172
>   format:
>     field:unsigned short common_type; offset:0; size:2; signed:0;
>     field:unsigned char common_flags; offset:2; size:1; signed:0;
>     field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
>     field:int common_pid; offset:4; size:4; signed:1;
>
>     field:unsigned long __probe_ip; offset:8; size:8; signed:0;
>     field:__data_loc char[] pathname; offset:16; size:4; signed:1;
>
>     print fmt: "(%lx) pathname=\"%s\"", REC->__probe_ip, REC->pathname

Instead of using "__get_str(pathname)" it referenced it directly.

Link: http://lkml.kernel.org/r/20200124100742.4050c15e@gandalf.local.home

Cc: stable@vger.kernel.org
Fixes: 88903c4643 ("tracing/probe: Add ustring type for user-space string")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reported-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-27 10:56:02 -05:00
David S. Miller
9e0703a265 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2020-01-27

The following pull-request contains BPF updates for your *net-next* tree.

We've added 20 non-merge commits during the last 5 day(s) which contain
a total of 24 files changed, 433 insertions(+), 104 deletions(-).

The main changes are:

1) Make BPF trampolines and dispatcher aware for the stack unwinder, from Jiri Olsa.

2) Improve handling of failed CO-RE relocations in libbpf, from Andrii Nakryiko.

3) Several fixes to BPF sockmap and reuseport selftests, from Lorenz Bauer.

4) Various cleanups in BPF devmap's XDP flush code, from John Fastabend.

5) Fix BPF flow dissector when used with port ranges, from Yoshiki Komachi.

6) Fix bpffs' map_seq_next callback to always inc position index, from Vasily Averin.

7) Allow overriding LLVM tooling for runqslower utility, from Andrey Ignatov.

8) Silence false-positive lockdep splats in devmap hash lookup, from Amol Grover.

9) Fix fentry/fexit selftests to initialize a variable before use, from John Sperbeck.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-27 14:31:40 +01:00
Rafael J. Wysocki
245224d1cb Merge branches 'pm-cpufreq' and 'pm-sleep'
* pm-cpufreq:
  cpufreq: loongson2_cpufreq: adjust cpufreq uses of LOONGSON_CHIPCFG
  cpufreq: brcmstb-avs: fix imbalance of cpufreq policy refcount
  cpufreq: intel_pstate: fix spelling mistake: "Whethet" -> "Whether"
  cpufreq: s3c: fix unbalances of cpufreq policy refcount
  cpufreq: imx-cpufreq-dt: Add i.MX8MP support
  cpufreq: Use imx-cpufreq-dt for i.MX8MP's speed grading
  cpufreq: tegra186: convert to devm_platform_ioremap_resource
  cpufreq: kirkwood: convert to devm_platform_ioremap_resource
  cpufreq: CPPC: put ACPI table after using it
  cpufreq : CPPC: Break out if HiSilicon CPPC workaround is matched

* pm-sleep:
  PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior
  PM: hibernate: fix spelling mistake "shapshot" -> "snapshot"
  PM: hibernate: Add more logging on hibernation failure
  PM: hibernate: improve arithmetic division in preallocate_highmem_fraction()
  PM: wakeup: Show statistics for deleted wakeup sources again
  PM: sleep: Switch to rtc_time64_to_tm()/rtc_tm_to_time64()
2020-01-27 11:29:09 +01:00
John Fastabend
b23bfa5633 bpf, xdp: Remove no longer required rcu_read_{un}lock()
Now that we depend on rcu_call() and synchronize_rcu() to also wait
for preempt_disabled region to complete the rcu read critical section
in __dev_map_flush() is no longer required. Except in a few special
cases in drivers that need it for other reasons.

These originally ensured the map reference was safe while a map was
also being free'd. And additionally that bpf program updates via
ndo_bpf did not happen while flush updates were in flight. But flush
by new rules can only be called from preempt-disabled NAPI context.
The synchronize_rcu from the map free path and the rcu_call from the
delete path will ensure the reference there is safe. So lets remove
the rcu_read_lock and rcu_read_unlock pair to avoid any confusion
around how this is being protected.

If the rcu_read_lock was required it would mean errors in the above
logic and the original patch would also be wrong.

Now that we have done above we put the rcu_read_lock in the driver
code where it is needed in a driver dependent way. I think this
helps readability of the code so we know where and why we are
taking read locks. Most drivers will not need rcu_read_locks here
and further XDP drivers already have rcu_read_locks in their code
paths for reading xdp programs on RX side so this makes it symmetric
where we don't have half of rcu critical sections define in driver
and the other half in devmap.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/1580084042-11598-4-git-send-email-john.fastabend@gmail.com
2020-01-27 11:16:25 +01:00
John Fastabend
42a84a8cd0 bpf, xdp: Update devmap comments to reflect napi/rcu usage
Now that we rely on synchronize_rcu and call_rcu waiting to
exit perempt-disable regions (NAPI) lets update the comments
to reflect this.

Fixes: 0536b85239 ("xdp: Simplify devmap cleanup")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/1580084042-11598-2-git-send-email-john.fastabend@gmail.com
2020-01-27 11:16:20 +01:00
Vasily Averin
90435a7891 bpf: map_seq_next should always increase position index
If seq_file .next fuction does not change position index,
read after some lseek can generate an unexpected output.

See also: https://bugzilla.kernel.org/show_bug.cgi?id=206283

v1 -> v2: removed missed increment in end of function

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/eca84fdd-c374-a154-d874-6c7b55fc3bc4@virtuozzo.com
2020-01-27 10:54:32 +01:00
Madhuparna Bhowmik
913292c97d sched.h: Annotate sighand_struct with __rcu
This patch fixes the following sparse errors by annotating the
sighand_struct with __rcu

kernel/fork.c:1511:9: error: incompatible types in comparison expression
kernel/exit.c💯19: error: incompatible types in comparison expression
kernel/signal.c:1370:27: error: incompatible types in comparison expression

This fix introduces the following sparse error in signal.c due to
checking the sighand pointer without rcu primitives:

kernel/signal.c:1386:21: error: incompatible types in comparison expression

This new sparse error is also fixed in this patch.

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20200124045908.26389-1-madhuparnabhowmik10@gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-01-26 10:54:47 +01:00
David S. Miller
4d8773b68e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Minor conflict in mlx5 because changes happened to code that has
moved meanwhile.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-26 10:40:21 +01:00
Paul E. McKenney
59d8cc6b2e rcu: Forgive slow expedited grace periods at boot time
Boot-time processing often loops in the kernel longer than one might
prefer, which can prevent expedited grace periods from completing in
a timely manner.  This in turn triggers a splat In nohz_full CPUs  One
could argue that long-looping code should be fixed, but on the other hand,
boot time is a bit special.

This commit therefore removes the splat.  Later commits will add the
splat back in, but in a way that removes false positives.

Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-25 12:00:40 -08:00
Steven Rostedt (VMware)
24589e3a20 tracing: Use pr_err() instead of WARN() for memory failures
As warnings can trigger panics, especially when "panic_on_warn" is set,
memory failure warnings can cause panics and fail fuzz testers that are
stressing memory.

Create a MEM_FAIL() macro to use instead of WARN() in the tracing code
(perhaps this should be a kernel wide macro?), and use that for memory
failure issues. This should stop failing fuzz tests due to warnings.

Link: https://lore.kernel.org/r/CACT4Y+ZP-7np20GVRu3p+eZys9GPtbu+JpfV+HtsufAzvTgJrg@mail.gmail.com

Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-25 10:52:30 -05:00
Jiri Olsa
e9b4e606c2 bpf: Allow to resolve bpf trampoline and dispatcher in unwind
When unwinding the stack we need to identify each address
to successfully continue. Adding latch tree to keep trampolines
for quick lookup during the unwind.

The patch uses first 48 bytes for latch tree node, leaving 4048
bytes from the rest of the page for trampoline or dispatcher
generated code.

It's still enough not to affect trampoline and dispatcher progs
maximum counts.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200123161508.915203-3-jolsa@kernel.org
2020-01-25 07:12:40 -08:00
Jiri Olsa
84ad7a7ab6 bpf: Allow BTF ctx access for string pointers
When accessing the context we allow access to arguments with
scalar type and pointer to struct. But we deny access for
pointer to scalar type, which is the case for many functions.

Alexei suggested to take conservative approach and allow
currently only string pointer access, which is the case
for most functions now:

Adding check if the pointer is to string type and allow access to it.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200123161508.915203-2-jolsa@kernel.org
2020-01-25 07:12:40 -08:00
Ingo Molnar
f8a4bb6bfa Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:

 - Expedited grace-period updates
 - kfree_rcu() updates
 - RCU list updates
 - Preemptible RCU updates
 - Torture-test updates
 - Miscellaneous fixes
 - Documentation updates

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-25 10:05:23 +01:00
Steven Rostedt (VMware)
28394da258 tracing: Decrement trace_array when bootconfig creates an instance
The trace_array_get_by_name() creates a ftrace instance and
trace_array_put() is used to remove the reference. Even though the
trace_array_get_by_name() creates the instance, it also adds a reference
count to it, that prevents user space from removing it.

As the bootconfig just creates the instance on boot up, it should still be
used where it can be deleted by user space after boot. A trace_array_put()
is required to let that happen.

Also, change the documentation on trace_array_get_by_name() to make this not
be so confusing.

Link: https://lore.kernel.org/r/20200124205927.76128804@rorschach.local.home

Fixes: 4f712a4d04 ("tracing/boot: Add instance node support")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-24 21:29:13 -05:00
Dan Carpenter
b3f7a6cd49 tracing: Remove unneeded NULL check
We checked "iter->trace" earlier so there is no need to check here.

Link: http://lkml.kernel.org/r/20141122183012.GB6994@mwanda

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-24 18:22:33 -05:00
Josef Bacik
cbc3b92ce0 tracing: Set kernel_stack's caller size properly
I noticed when trying to use the trace-cmd python interface that reading the raw
buffer wasn't working for kernel_stack events.  This is because it uses a
stubbed version of __dynamic_array that doesn't do the __data_loc trick and
encode the length of the array into the field.  Instead it just shows up as a
size of 0.  So change this to __array and set the len to FTRACE_STACK_ENTRIES
since this is what we actually do in practice and matches how user_stack_trace
works.

Link: http://lkml.kernel.org/r/1411589652-1318-1-git-send-email-jbacik@fb.com

Signed-off-by: Josef Bacik <jbacik@fb.com>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-24 18:09:40 -05:00
Luis Henriques
afccc00f75 tracing: Fix tracing_stat return values in error handling paths
tracing_stat_init() was always returning '0', even on the error paths.  It
now returns -ENODEV if tracing_init_dentry() fails or -ENOMEM if it fails
to created the 'trace_stat' debugfs directory.

Link: http://lkml.kernel.org/r/1410299381-20108-1-git-send-email-luis.henriques@canonical.com

Fixes: ed6f1c996b ("tracing: Check return value of tracing_init_dentry()")
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
[ Pulled from the archeological digging of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-24 18:06:48 -05:00
Steven Rostedt (VMware)
dfb6cd1e65 tracing: Fix very unlikely race of registering two stat tracers
Looking through old emails in my INBOX, I came across a patch from Luis
Henriques that attempted to fix a race of two stat tracers registering the
same stat trace (extremely unlikely, as this is done in the kernel, and
probably doesn't even exist). The submitted patch wasn't quite right as it
needed to deal with clean up a bit better (if two stat tracers were the
same, it would have the same files).

But to make the code cleaner, all we needed to do is to keep the
all_stat_sessions_mutex held for most of the registering function.

Link: http://lkml.kernel.org/r/1410299375-20068-1-git-send-email-luis.henriques@canonical.com

Fixes: 002bb86d8d ("tracing/ftrace: separate events tracing and stats tracing engine")
Reported-by: Luis Henriques <luis.henriques@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-24 17:54:06 -05:00
Stephen Boyd
fd928f3e32 alarmtimer: Make alarmtimer_get_rtcdev() a stub when CONFIG_RTC_CLASS=n
The stubbed version of alarmtimer_get_rtcdev() is not exported.
so this won't work if this function is used in a module when
CONFIG_RTC_CLASS=n.

Move the stub function to the header file and make it inline so that
callers don't have to worry about linking against this symbol.

rtcdev isn't used outside of this ifdef so it's not required to be
redefined to NULL. Drop that while touching this area.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200124055849.154411-4-swboyd@chromium.org
2020-01-24 21:03:53 +01:00
Stephen Boyd
7c94caca87 alarmtimer: Use wakeup source from alarmtimer platform device
Use the wakeup source that can be associated with the 'alarmtimer'
platform device instead of registering another one by hand.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200124055849.154411-3-swboyd@chromium.org
2020-01-24 21:00:21 +01:00
Stephen Boyd
c79108bd19 alarmtimer: Make alarmtimer platform device child of RTC device
The alarmtimer_suspend() function will fail if an RTC device is on a bus
such as SPI or i2c and that RTC device registers and probes after
alarmtimer_init() registers and probes the 'alarmtimer' platform device.

This is because system wide suspend suspends devices in the reverse order
of their probe. When alarmtimer_suspend() attempts to program the RTC for a
wakeup it will try to program an RTC device on a bus that has already been
suspended.

Move the alarmtimer device registration to happen when the RTC which is
used for wakeup is registered. Register the 'alarmtimer' platform device as
a child of the RTC device too, so that it can be guaranteed that the RTC
device won't be suspended when alarmtimer_suspend() is called.

Reported-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200124055849.154411-2-swboyd@chromium.org
2020-01-24 21:00:20 +01:00
Stephen Boyd
6b088cefbe alarmtimer: Update alarmtimer_get_rtcdev() docs to reflect reality
This function doesn't do anything like this comment says when an RTC device
hasn't been chosen. It looks like we used to do something like that before
commit 8bc0dafb5c ("alarmtimers: Rework RTC device selection using class
interface") but that's long gone now. Remove this sentence to avoid
confusing the reader.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200124055849.154411-5-swboyd@chromium.org
2020-01-24 21:00:20 +01:00
Sebastian Andrzej Siewior
cb923159bb smp: Remove allocation mask from on_each_cpu_cond.*()
The allocation mask is no longer used by on_each_cpu_cond() and
on_each_cpu_cond_mask() and can be removed.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20200117090137.1205765-4-bigeasy@linutronix.de
2020-01-24 20:40:09 +01:00
Sebastian Andrzej Siewior
67719ef25e smp: Add a smp_cond_func_t argument to smp_call_function_many()
on_each_cpu_cond_mask() allocates a new CPU mask. The newly allocated
mask is a subset of the provided mask based on the conditional function.

This memory allocation can be avoided by extending smp_call_function_many()
with the conditional function and performing the remote function call based
on the mask and the conditional function.

Rename smp_call_function_many() to smp_call_function_many_cond() and add
the smp_cond_func_t argument. If smp_cond_func_t is provided then it is
used before invoking the function.  Provide smp_call_function_many() with
cond_func set to NULL.  Let on_each_cpu_cond_mask() use
smp_call_function_many_cond().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20200117090137.1205765-3-bigeasy@linutronix.de
2020-01-24 20:40:09 +01:00
Sebastian Andrzej Siewior
5671d814db smp: Use smp_cond_func_t as type for the conditional function
Use a typdef for the conditional function instead defining it each time in
the function prototype.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20200117090137.1205765-2-bigeasy@linutronix.de
2020-01-24 20:40:08 +01:00
Thomas Gleixner
43ee74487b irqchip updates for Linux 5.6:
- Conversion of the SiFive PLIC to hierarchical domains
 - New SiFive GPIO irqchip driver
 - New Aspeed SCI irqchip driver
 - New NXP INTMUX irqchip driver
 - Additional support for the Meson A1 GPIO irqchip
 - First part of the GICv4.1 support
 - Assorted fixes
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Merge tag 'irqchip-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates from Marc Zyngier:

- Conversion of the SiFive PLIC to hierarchical domains
- New SiFive GPIO irqchip driver
- New Aspeed SCI irqchip driver
- New NXP INTMUX irqchip driver
- Additional support for the Meson A1 GPIO irqchip
- First part of the GICv4.1 support
- Assorted fixes
2020-01-24 20:08:51 +01:00
Paul E. McKenney
0e247386d9 Merge branches 'doc.2019.12.10a', 'exp.2019.12.09a', 'fixes.2020.01.24a', 'kfree_rcu.2020.01.24a', 'list.2020.01.10a', 'preempt.2020.01.24a' and 'torture.2019.12.09a' into HEAD
doc.2019.12.10a: Documentations updates
exp.2019.12.09a: Expedited grace-period updates
fixes.2020.01.24a: Miscellaneous fixes
kfree_rcu.2020.01.24a: Batch kfree_rcu() work
list.2020.01.10a: RCU-protected-list updates
preempt.2020.01.24a: Preemptible RCU updates
torture.2019.12.09a: Torture-test updates
2020-01-24 10:37:27 -08:00
Paul E. McKenney
f6105fc2a9 rcu: Remove unused stop-machine #include
Long ago, RCU used the stop-machine mechanism to implement expedited
grace periods, but no longer does so.  This commit therefore removes
the no-longer-needed #includes of linux/stop_machine.h.

Link: https://lwn.net/Articles/805317/
Reported-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:52 -08:00
Paul E. McKenney
844a378de3 srcu: Apply *_ONCE() to ->srcu_last_gp_end
The ->srcu_last_gp_end field is accessed from any CPU at any time
by synchronize_srcu(), so non-initialization references need to use
READ_ONCE() and WRITE_ONCE().  This commit therefore makes that change.

Reported-by: syzbot+08f3e9d26e5541e1ecf2@syzkaller.appspotmail.com
Acked-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:51 -08:00
Paul E. McKenney
7441e7661d rcu: Switch force_qs_rnp() to for_each_leaf_node_cpu_mask()
Currently, force_qs_rnp() uses a for_each_leaf_node_possible_cpu()
loop containing a check of the current CPU's bit in ->qsmask.
This works, but this commit saves three lines by instead using
for_each_leaf_node_cpu_mask(), which combines the functionality of
for_each_leaf_node_possible_cpu() and leaf_node_cpu_bit().  This commit
also replaces the use of the local variable "bit" with rdp->grpmask.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:51 -08:00
Ben Dooks
e1350e8e0e rcu: Move rcu_{expedited,normal} definitions into rcupdate.h
This commit moves the rcu_{expedited,normal} definitions from
kernel/rcu/update.c to include/linux/rcupdate.h to make sure they are
in sync, and also to avoid the following warning from sparse:

kernel/ksysfs.c:150:5: warning: symbol 'rcu_expedited' was not declared. Should it be static?
kernel/ksysfs.c:167:5: warning: symbol 'rcu_normal' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:50 -08:00
Lai Jiangshan
e2167b38c8 rcu: Move gp_state_names[] and gp_state_getname() to tree_stall.h
Only tree_stall.h needs to get name from GP state, so this commit
moves the gp_state_names[] array and the gp_state_getname()
from kernel/rcu/tree.h and kernel/rcu/tree.c, respectively, to
kernel/rcu/tree_stall.h.  While moving gp_state_names[], this commit
uses the GCC syntax to ensure that the right string is associated with
the right CPP macro.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:45 -08:00
Lai Jiangshan
4778339df0 rcu: Remove the declaration of call_rcu() in tree.h
The call_rcu() function is an external RCU API that is declared in
include/linux/rcupdate.h.  There is thus no point in redeclaring it
in kernel/rcu/tree.h, so this commit removes that redundant declaration.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:38 -08:00
Lai Jiangshan
2488a5e695 rcu: Fix tracepoint tracking RCU CPU kthread utilization
In the call to trace_rcu_utilization() at the start of the loop in
rcu_cpu_kthread(), "rcu_wait" is incorrect, plus this trace event needs
to be hoisted above the loop to balance with either the "rcu_wait" or
"rcu_yield", depending on how the loop exits.  This commit therefore
makes these changes.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:31 -08:00
Lai Jiangshan
822175e729 rcu: Fix harmless omission of "CONFIG_" from #if condition
The C preprocessor macros SRCU and TINY_RCU should instead be CONFIG_SRCU
and CONFIG_TINY_RCU, respectively in the #f in kernel/rcu/rcu.h. But
there is no harm when "TINY_RCU" is wrongly used, which are always
non-defined, which makes "!defined(TINY_RCU)" always true, which means
the code block is always included, and the included code block doesn't
cause any compilation error so far in CONFIG_TINY_RCU builds.  It is
also the reason this change should not be taken in -stable.

This commit adds the needed "CONFIG_" prefix to both macros.

Not for -stable.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:33:13 -08:00
Paul E. McKenney
5b14557b07 rcu: Avoid tick_dep_set_cpu() misordering
In the current code, rcu_nmi_enter_common() might decide to turn on
the tick using tick_dep_set_cpu(), but be delayed just before doing so.
Then the grace-period kthread might notice that the CPU in question had
in fact gone through a quiescent state, thus turning off the tick using
tick_dep_clear_cpu().  The later invocation of tick_dep_set_cpu() would
then incorrectly leave the tick on.

This commit therefore enlists the aid of the leaf rcu_node structure's
->lock to ensure that decisions to enable or disable the tick are
carried out before they can be reversed.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:27:33 -08:00
Lai Jiangshan
77339e61aa rcu: Provide wrappers for uses of ->rcu_read_lock_nesting
This commit provides wrapper functions for uses of ->rcu_read_lock_nesting
to improve readability and to ease future changes to support inlining
of __rcu_read_lock() and __rcu_read_unlock().

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:27:33 -08:00
Paul E. McKenney
c51f83c315 rcu: Use READ_ONCE() for ->expmask in rcu_read_unlock_special()
The rcu_node structure's ->expmask field is updated only when holding the
->lock, but is also accessed locklessly.  This means that all ->expmask
updates must use WRITE_ONCE() and all reads carried out without holding
->lock must use READ_ONCE().  This commit therefore changes the lockless
->expmask read in rcu_read_unlock_special() to use READ_ONCE().

Reported-by: syzbot+99f4ddade3c22ab0cf23@syzkaller.appspotmail.com
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Marco Elver <elver@google.com>
2020-01-24 10:27:33 -08:00
Lai Jiangshan
3717e1e9f2 rcu: Clear ->rcu_read_unlock_special only once
In rcu_preempt_deferred_qs_irqrestore(), ->rcu_read_unlock_special is
cleared one piece at a time.  Given that the "if" statements in this
function use the copy in "special", this commit removes the clearing
of the individual pieces in favor of clearing ->rcu_read_unlock_special
in one go just after it has been determined to be non-zero.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:27:33 -08:00
Lai Jiangshan
2eeba5838f rcu: Clear .exp_hint only when deferred quiescent state has been reported
Currently, the .exp_hint flag is cleared in rcu_read_unlock_special(),
which works, but which can also prevent subsequent rcu_read_unlock() calls
from helping expedite the quiescent state needed by an ongoing expedited
RCU grace period.  This commit therefore defers clearing of .exp_hint
from rcu_read_unlock_special() to rcu_preempt_deferred_qs_irqrestore(),
thus ensuring that intervening calls to rcu_read_unlock() have a chance
to help end the expedited grace period.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:27:33 -08:00
Lai Jiangshan
c130d2dc93 rcu: Rename some instance of CONFIG_PREEMPTION to CONFIG_PREEMPT_RCU
CONFIG_PREEMPTION and CONFIG_PREEMPT_RCU are always identical,
but some code depends on CONFIG_PREEMPTION to access to
rcu_preempt functionality. This patch changes CONFIG_PREEMPTION
to CONFIG_PREEMPT_RCU in these cases.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:26:28 -08:00
Joel Fernandes (Google)
189a6883dc rcu: Remove kfree_call_rcu_nobatch()
Now that the kfree_rcu() special-casing has been removed from tree RCU,
this commit removes kfree_call_rcu_nobatch() since it is no longer needed.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:24:31 -08:00
Joel Fernandes (Google)
77a40f9703 rcu: Remove kfree_rcu() special casing and lazy-callback handling
This commit removes kfree_rcu() special-casing and the lazy-callback
handling from Tree RCU.  It moves some of this special casing to Tiny RCU,
the removal of which will be the subject of later commits.

This results in a nice negative delta.

Suggested-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Add slab.h #include, thanks to kbuild test robot <lkp@intel.com>. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:24:31 -08:00
Joel Fernandes (Google)
e99637becb rcu: Add support for debug_objects debugging for kfree_rcu()
This commit applies RCU's debug_objects debugging to the new batched
kfree_rcu() implementations.  The object is queued at the kfree_rcu()
call and dequeued during reclaim.

Tested that enabling CONFIG_DEBUG_OBJECTS_RCU_HEAD successfully detects
double kfree_rcu() calls.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Fix IRQ per kbuild test robot <lkp@intel.com> feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:24:31 -08:00
Joel Fernandes (Google)
0392bebebf rcu: Add multiple in-flight batches of kfree_rcu() work
During testing, it was observed that amount of memory consumed due
kfree_rcu() batching is 300-400MB. Previously we had only a single
head_free pointer pointing to the list of rcu_head(s) that are to be
freed after a grace period. Until this list is drained, we cannot queue
any more objects on it since such objects may not be ready to be
reclaimed when the worker thread eventually gets to drainin g the
head_free list.

We can do better by maintaining multiple lists as done by this patch.
Testing shows that memory consumption came down by around 100-150MB with
just adding another list. Adding more than 1 additional list did not
show any improvement.

Suggested-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Code style and initialization handling. ]
[ paulmck: Fix field name, reported by kbuild test robot <lkp@intel.com>. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:24:31 -08:00
Joel Fernandes
569d767087 rcu: Make kfree_rcu() use a non-atomic ->monitor_todo
Because the ->monitor_todo field is always protected by krcp->lock,
this commit downgrades from xchg() to non-atomic unmarked assignment
statements.

Signed-off-by: Joel Fernandes <joel@joelfernandes.org>
[ paulmck: Update to include early-boot kick code. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:24:31 -08:00
Joel Fernandes (Google)
e6e78b004f rcuperf: Add kfree_rcu() performance Tests
This test runs kfree_rcu() in a loop to measure performance of the new
kfree_rcu() batching functionality.

The following table shows results when booting with arguments:
rcuperf.kfree_loops=20000 rcuperf.kfree_alloc_num=8000
rcuperf.kfree_rcu_test=1 rcuperf.kfree_no_batch=X

rcuperf.kfree_no_batch=X    # Grace Periods	Test Duration (s)
  X=1 (old behavior)              9133                 11.5
  X=0 (new behavior)              1732                 12.5

On a 16 CPU system with the above boot parameters, we see that the total
number of grace periods that elapse during the test drops from 9133 when
not batching to 1732 when batching (a 5X improvement). The kfree_rcu()
flood itself slows down a bit when batching, though, as shown.

Note that the active memory consumption during the kfree_rcu() flood
does increase to around 200-250MB due to the batching (from around 50MB
without batching). However, this memory consumption is relatively
constant. In other words, the system is able to keep up with the
kfree_rcu() load. The memory consumption comes down considerably if
KFREE_DRAIN_JIFFIES is increased from HZ/50 to HZ/80. A later patch will
reduce memory consumption further by using multiple lists.

Also, when running the test, please disable CONFIG_DEBUG_PREEMPT and
CONFIG_PROVE_RCU for realistic comparisons with/without batching.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:24:31 -08:00
Byungchul Park
a35d16905e rcu: Add basic support for kfree_rcu() batching
Recently a discussion about stability and performance of a system
involving a high rate of kfree_rcu() calls surfaced on the list [1]
which led to another discussion how to prepare for this situation.

This patch adds basic batching support for kfree_rcu(). It is "basic"
because we do none of the slab management, dynamic allocation, code
moving or any of the other things, some of which previous attempts did
[2]. These fancier improvements can be follow-up patches and there are
different ideas being discussed in those regards. This is an effort to
start simple, and build up from there. In the future, an extension to
use kfree_bulk and possibly per-slab batching could be done to further
improve performance due to cache-locality and slab-specific bulk free
optimizations. By using an array of pointers, the worker thread
processing the work would need to read lesser data since it does not
need to deal with large rcu_head(s) any longer.

Torture tests follow in the next patch and show improvements of around
5x reduction in number of  grace periods on a 16 CPU system. More
details and test data are in that patch.

There is an implication with rcu_barrier() with this patch. Since the
kfree_rcu() calls can be batched, and may not be handed yet to the RCU
machinery in fact, the monitor may not have even run yet to do the
queue_rcu_work(), there seems no easy way of implementing rcu_barrier()
to wait for those kfree_rcu()s that are already made. So this means a
kfree_rcu() followed by an rcu_barrier() does not imply that memory will
be freed once rcu_barrier() returns.

Another implication is higher active memory usage (although not
run-away..) until the kfree_rcu() flooding ends, in comparison to
without batching. More details about this are in the second patch which
adds an rcuperf test.

Finally, in the near future we will get rid of kfree_rcu() special casing
within RCU such as in rcu_do_batch and switch everything to just
batching. Currently we don't do that since timer subsystem is not yet up
and we cannot schedule the kfree_rcu() monitor as the timer subsystem's
lock are not initialized. That would also mean getting rid of
kfree_call_rcu_nobatch() entirely.

[1] http://lore.kernel.org/lkml/20190723035725-mutt-send-email-mst@kernel.org
[2] https://lkml.org/lkml/2017/12/19/824

Cc: kernel-team@android.com
Cc: kernel-team@lge.com
Co-developed-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Applied 0day and Paul Walmsley feedback on ->monitor_todo. ]
[ paulmck: Make it work during early boot. ]
[ paulmck: Add a crude early boot self-test. ]
[ paulmck: Style adjustments and experimental docbook structure header. ]
Link: https://lore.kernel.org/lkml/alpine.DEB.2.21.9999.1908161931110.32497@viisi.sifive.com/T/#me9956f66cb611b95d26ae92700e1d901f46e8c59
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-01-24 10:17:03 -08:00
Amol Grover
485ec2ea9c bpf, devmap: Pass lockdep expression to RCU lists
head is traversed using hlist_for_each_entry_rcu outside an RCU
read-side critical section but under the protection of dtab->index_lock.

Hence, add corresponding lockdep expression to silence false-positive
lockdep warnings, and harden RCU lists.

Fixes: 6f9d451ab1 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20200123120437.26506-1-frextrite@gmail.com
2020-01-23 23:01:16 +01:00
Linus Torvalds
34597c85be Various tracing fixes:
- Fix a function comparison warning for a xen trace event macro
  - Fix a double perf_event linking to a trace_uprobe_filter for multiple events
  - Fix suspicious RCU warnings in trace event code for using
     list_for_each_entry_rcu() when the "_rcu" portion wasn't needed.
  - Fix a bug in the histogram code when using the same variable
  - Fix a NULL pointer dereference when tracefs lockdown enabled and calling
     trace_set_default_clock()
 
 This v2 version contains:
 
  - A fix to a bug found with the double perf_event linking patch
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Merge tag 'trace-v5.5-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Various tracing fixes:

   - Fix a function comparison warning for a xen trace event macro

   - Fix a double perf_event linking to a trace_uprobe_filter for
     multiple events

   - Fix suspicious RCU warnings in trace event code for using
     list_for_each_entry_rcu() when the "_rcu" portion wasn't needed.

   - Fix a bug in the histogram code when using the same variable

   - Fix a NULL pointer dereference when tracefs lockdown enabled and
     calling trace_set_default_clock()

   - A fix to a bug found with the double perf_event linking patch"

* tag 'trace-v5.5-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/uprobe: Fix to make trace_uprobe_filter alignment safe
  tracing: Do not set trace clock if tracefs lockdown is in effect
  tracing: Fix histogram code when expression has same var as value
  tracing: trigger: Replace unneeded RCU-list traversals
  tracing/uprobe: Fix double perf_event linking on multiprobe uprobe
  tracing: xen: Ordered comparison of function pointers
2020-01-23 11:23:37 -08:00
Linus Torvalds
3a83c8c81c Power management fix for 5.5-rc8
Prevent the kernel from crashing during resume from hibernation
 if free pages contain leftover data from the restore kernel and
 init_on_free is set (Alexander Potapenko).
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Merge tag 'pm-5.5-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fix from Rafael Wysocki:
 "Prevent the kernel from crashing during resume from hibernation if
  free pages contain leftover data from the restore kernel and
  init_on_free is set (Alexander Potapenko)"

* tag 'pm-5.5-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: hibernate: fix crashes with init_on_free=1
2020-01-23 11:10:21 -08:00
Rafael J. Wysocki
322e929d19 Merge back new material related to system-wide PM for v5.6. 2020-01-23 16:00:56 +01:00
David S. Miller
954b3c4397 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-01-22

The following pull-request contains BPF updates for your *net-next* tree.

We've added 92 non-merge commits during the last 16 day(s) which contain
a total of 320 files changed, 7532 insertions(+), 1448 deletions(-).

The main changes are:

1) function by function verification and program extensions from Alexei.

2) massive cleanup of selftests/bpf from Toke and Andrii.

3) batched bpf map operations from Brian and Yonghong.

4) tcp congestion control in bpf from Martin.

5) bulking for non-map xdp_redirect form Toke.

6) bpf_send_signal_thread helper from Yonghong.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-23 08:10:16 +01:00
Martin KaFai Lau
5576b991e9 bpf: Add BPF_FUNC_jiffies64
This patch adds a helper to read the 64bit jiffies.  It will be used
in a later patch to implement the bpf_cubic.c.

The helper is inlined for jit_requested and 64 BITS_PER_LONG
as the map_gen_lookup().  Other cases could be considered together
with map_gen_lookup() if needed.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200122233646.903260-1-kafai@fb.com
2020-01-22 16:30:10 -08:00
Alexei Starovoitov
be8704ff07 bpf: Introduce dynamic program extensions
Introduce dynamic program extensions. The users can load additional BPF
functions and replace global functions in previously loaded BPF programs while
these programs are executing.

Global functions are verified individually by the verifier based on their types only.
Hence the global function in the new program which types match older function can
safely replace that corresponding function.

This new function/program is called 'an extension' of old program. At load time
the verifier uses (attach_prog_fd, attach_btf_id) pair to identify the function
to be replaced. The BPF program type is derived from the target program into
extension program. Technically bpf_verifier_ops is copied from target program.
The BPF_PROG_TYPE_EXT program type is a placeholder. It has empty verifier_ops.
The extension program can call the same bpf helper functions as target program.
Single BPF_PROG_TYPE_EXT type is used to extend XDP, SKB and all other program
types. The verifier allows only one level of replacement. Meaning that the
extension program cannot recursively extend an extension. That also means that
the maximum stack size is increasing from 512 to 1024 bytes and maximum
function nesting level from 8 to 16. The programs don't always consume that
much. The stack usage is determined by the number of on-stack variables used by
the program. The verifier could have enforced 512 limit for combined original
plus extension program, but it makes for difficult user experience. The main
use case for extensions is to provide generic mechanism to plug external
programs into policy program or function call chaining.

BPF trampoline is used to track both fentry/fexit and program extensions
because both are using the same nop slot at the beginning of every BPF
function. Attaching fentry/fexit to a function that was replaced is not
allowed. The opposite is true as well. Replacing a function that currently
being analyzed with fentry/fexit is not allowed. The executable page allocated
by BPF trampoline is not used by program extensions. This inefficiency will be
optimized in future patches.

Function by function verification of global function supports scalars and
pointer to context only. Hence program extensions are supported for such class
of global functions only. In the future the verifier will be extended with
support to pointers to structures, arrays with sizes, etc.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20200121005348.2769920-2-ast@kernel.org
2020-01-22 23:04:52 +01:00
Ming Lei
11ea68f553 genirq, sched/isolation: Isolate from handling managed interrupts
The affinity of managed interrupts is completely handled in the kernel and
cannot be changed via the /proc/irq/* interfaces from user space. As the
kernel tries to spread out interrupts evenly accross CPUs on x86 to prevent
vector exhaustion, it can happen that a managed interrupt whose affinity
mask contains both isolated and housekeeping CPUs is routed to an isolated
CPU. As a consequence IO submitted on a housekeeping CPU causes interrupts
on the isolated CPU.

Add a new sub-parameter 'managed_irq' for 'isolcpus' and the corresponding
logic in the interrupt affinity selection code.

The subparameter indicates to the interrupt affinity selection logic that
it should try to avoid the above scenario.

This isolation is best effort and only effective if the automatically
assigned interrupt mask of a device queue contains isolated and
housekeeping CPUs. If housekeeping CPUs are online then such interrupts are
directed to the housekeeping CPU so that IO submitted on the housekeeping
CPU cannot disturb the isolated CPU.

If a queue's affinity mask contains only isolated CPUs then this parameter
has no effect on the interrupt routing decision, though interrupts are only
happening when tasks running on those isolated CPUs submit IO. IO submitted
on housekeeping CPUs has no influence on those queues.

If the affinity mask contains both housekeeping and isolated CPUs, but none
of the contained housekeeping CPUs is online, then the interrupt is also
routed to an isolated CPU. Interrupts are only delivered when one of the
isolated CPUs in the affinity mask submits IO. If one of the contained
housekeeping CPUs comes online, the CPU hotplug logic migrates the
interrupt automatically back to the upcoming housekeeping CPU. Depending on
the type of interrupt controller, this can require that at least one
interrupt is delivered to the isolated CPU in order to complete the
migration.

[ tglx: Removed unused parameter, added and edited comments/documentation
  	and rephrased the changelog so it contains more details. ]

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200120091625.17912-1-ming.lei@redhat.com
2020-01-22 16:29:49 +01:00
Jules Irenge
eb5a4d0a9e hrtimer: Add missing sparse annotation for __run_timer()
Sparse reports a warning at __run_hrtimer()
|warning: context imbalance in __run_hrtimer() - unexpected unlock

Add the missing must_hold() annotation.

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200120224347.51843-1-jbi.octave@gmail.com
2020-01-22 15:50:11 +01:00
Masami Hiramatsu
b61387cb73 tracing/uprobe: Fix to make trace_uprobe_filter alignment safe
Commit 99c9a923e9 ("tracing/uprobe: Fix double perf_event
linking on multiprobe uprobe") moved trace_uprobe_filter on
trace_probe_event. However, since it introduced a flexible
data structure with char array and type casting, the
alignment of trace_uprobe_filter can be broken.

This changes the type of the array to trace_uprobe_filter
data strucure to fix it.

Link: http://lore.kernel.org/r/20200120124022.GA14897@hirez.programming.kicks-ass.net
Link: http://lkml.kernel.org/r/157966340499.5107.10978352478952144902.stgit@devnote2

Fixes: 99c9a923e9 ("tracing/uprobe: Fix double perf_event linking on multiprobe uprobe")
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-22 07:09:20 -05:00
Alex Shi
659ded3027 trace/kprobe: Remove unused MAX_KPROBE_CMDLINE_SIZE
This limitation are never lunched from introduce commit 970988e19e
("tracing/kprobe: Add kprobe_event= boot parameter")

Could we remove it if no intention to implement it?

Link: http://lkml.kernel.org/r/1579586075-45132-1-git-send-email-alex.shi@linux.alibaba.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-22 07:07:38 -05:00
Steven Rostedt (VMware)
34423f250a tracing: Fix uninitialized buffer var on early exit to trace_vbprintk()
If we exit due to a bad input to trace_printk() (highly unlikely), then the
buffer variable will not be initialized when we unnest the ring buffer.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-22 06:44:50 -05:00
Alexei Starovoitov
f59bbfc2f6 bpf: Fix error path under memory pressure
Restore the 'if (env->cur_state)' check that was incorrectly removed during
code move. Under memory pressure env->cur_state can be freed and zeroed inside
do_check(). Hence the check is necessary.

Fixes: 51c39bb1d5 ("bpf: Introduce function-by-function verification")
Reported-by: syzbot+b296579ba5015704d9fa@syzkaller.appspotmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200122024138.3385590-1-ast@kernel.org
2020-01-22 12:09:02 +01:00
Alexei Starovoitov
05d57f1793 bpf: Fix trampoline usage in preempt
Though the second half of trampoline page is unused a task could be
preempted in the middle of the first half of trampoline and two
updates to trampoline would change the code from underneath the
preempted task. Hence wait for tasks to voluntarily schedule or go
to userspace. Add similar wait before freeing the trampoline.

Fixes: fec56f5890 ("bpf: Introduce BPF trampoline")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/bpf/20200121032231.3292185-1-ast@kernel.org
2020-01-22 11:31:21 +01:00
Dan Carpenter
532f49a6f1 tracing/boot: Fix an IS_ERR() vs NULL bug
The trace_array_get_by_name() function doesn't return error pointers,
it returns NULL on error.

Link: http://lkml.kernel.org/r/20200117053007.5h2juv272pokqhtq@kili.mountain

Fixes: 4f712a4d04 ("tracing/boot: Add instance node support")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-21 18:41:39 -05:00
Alex Shi
141597204e tracing: Remove unused TRACE_SEQ_BUF_USED
This macro isn't used from commit 3a161d99c4 ("tracing: Create
seq_buf layer in trace_seq"). so no needs to keep it.

Link: http://lkml.kernel.org/r/1579586086-45543-1-git-send-email-alex.shi@linux.alibaba.com

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-21 18:39:54 -05:00
Alex Shi
b83479482f ring-buffer: Remove abandoned macro RB_MISSED_FLAGS
This macro isn't used since commit d325c40296 ("ring-buffer: Remove
unused function ring_buffer_page_len()"), so better to remove it.

Link: http://lkml.kernel.org/r/1579586080-45300-1-git-send-email-alex.shi@linux.alibaba.com

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-21 18:38:02 -05:00
Al Viro
b87121dd3f bpf: don't bother with getname/kern_path - use user_path_at
kernel/bpf/inode.c misuses kern_path...() - it's much simpler (and
more efficient, on top of that) to use user_path...() counterparts
rather than bothering with doing getname() manually.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200120232858.GF8904@ZenIV.linux.org.uk
2020-01-21 23:46:21 +01:00
Alex Shi
aff4866db5 ftrace: Remove NR_TO_INIT macro
This macro isn't used from commit cb7be3b2fc ("ftrace: remove
daemon"). So no needs to keep it.

Link: http://lkml.kernel.org/r/1579586063-44984-1-git-send-email-alex.shi@linux.alibaba.com

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-21 17:30:39 -05:00
Alex Shi
9a09cd74e7 ftrace: Remove abandoned macros
These 2 macros aren't used from commit eee8ded131 ("ftrace: Have the
function probes call their own function"), so remove them.

Link: http://lkml.kernel.org/r/1579585807-43316-1-git-send-email-alex.shi@linux.alibaba.com

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-21 17:28:35 -05:00
Brian Vazquez
2e3a94aa2b bpf: Fix memory leaks in generic update/delete batch ops
Generic update/delete batch ops functions were using __bpf_copy_key
without properly freeing the memory. Handle the memory allocation and
copy_from_user separately.

Fixes: aa2e93b8e5 ("bpf: Add generic support for update and delete batch ops")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200119194040.128369-1-brianvv@google.com
2020-01-20 22:27:51 +01:00
Masami Ichikawa
bf24daac8f tracing: Do not set trace clock if tracefs lockdown is in effect
When trace_clock option is not set and unstable clcok detected,
tracing_set_default_clock() sets trace_clock(ThinkPad A285 is one of
case). In that case, if lockdown is in effect, null pointer
dereference error happens in ring_buffer_set_clock().

Link: http://lkml.kernel.org/r/20200116131236.3866925-1-masami256@gmail.com

Cc: stable@vger.kernel.org
Fixes: 17911ff38a ("tracing: Add locked_down checks to the open calls of files created for tracefs")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1788488
Signed-off-by: Masami Ichikawa <masami256@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-20 16:18:14 -05:00
Steven Rostedt (VMware)
8bcebc77e8 tracing: Fix histogram code when expression has same var as value
While working on a tool to convert SQL syntex into the histogram language of
the kernel, I discovered the following bug:

 # echo 'first u64 start_time u64 end_time pid_t pid u64 delta' >> synthetic_events
 # echo 'hist:keys=pid:start=common_timestamp' > events/sched/sched_waking/trigger
 # echo 'hist:keys=next_pid:delta=common_timestamp-$start,start2=$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger

Would not display any histograms in the sched_switch histogram side.

But if I were to swap the location of

  "delta=common_timestamp-$start" with "start2=$start"

Such that the last line had:

 # echo 'hist:keys=next_pid:start2=$start,delta=common_timestamp-$start:onmatch(sched.sched_waking).trace(first,$start2,common_timestamp,next_pid,$delta)' > events/sched/sched_switch/trigger

The histogram works as expected.

What I found out is that the expressions clear out the value once it is
resolved. As the variables are resolved in the order listed, when
processing:

  delta=common_timestamp-$start

The $start is cleared. When it gets to "start2=$start", it errors out with
"unresolved symbol" (which is silent as this happens at the location of the
trace), and the histogram is dropped.

When processing the histogram for variable references, instead of adding a
new reference for a variable used twice, use the same reference. That way,
not only is it more efficient, but the order will no longer matter in
processing of the variables.

From Tom Zanussi:

 "Just to clarify some more about what the problem was is that without
  your patch, we would have two separate references to the same variable,
  and during resolve_var_refs(), they'd both want to be resolved
  separately, so in this case, since the first reference to start wasn't
  part of an expression, it wouldn't get the read-once flag set, so would
  be read normally, and then the second reference would do the read-once
  read and also be read but using read-once.  So everything worked and
  you didn't see a problem:

   from: start2=$start,delta=common_timestamp-$start

  In the second case, when you switched them around, the first reference
  would be resolved by doing the read-once, and following that the second
  reference would try to resolve and see that the variable had already
  been read, so failed as unset, which caused it to short-circuit out and
  not do the trigger action to generate the synthetic event:

   to: delta=common_timestamp-$start,start2=$start

  With your patch, we only have the single resolution which happens
  correctly the one time it's resolved, so this can't happen."

Link: https://lore.kernel.org/r/20200116154216.58ca08eb@gandalf.local.home

Cc: stable@vger.kernel.org
Fixes: 067fe038e7 ("tracing: Add variable reference handling to hist triggers")
Reviewed-by: Tom Zanuss <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-20 16:11:47 -05:00
Kevin Hao
0f394daef8 irqdomain: Fix a memory leak in irq_domain_push_irq()
Fix a memory leak reported by kmemleak:
unreferenced object 0xffff000bc6f50e80 (size 128):
  comm "kworker/23:2", pid 201, jiffies 4294894947 (age 942.132s)
  hex dump (first 32 bytes):
    00 00 00 00 41 00 00 00 86 c0 03 00 00 00 00 00  ....A...........
    00 a0 b2 c6 0b 00 ff ff 40 51 fd 10 00 80 ff ff  ........@Q......
  backtrace:
    [<00000000e62d2240>] kmem_cache_alloc_trace+0x1a4/0x320
    [<00000000279143c9>] irq_domain_push_irq+0x7c/0x188
    [<00000000d9f4c154>] thunderx_gpio_probe+0x3ac/0x438
    [<00000000fd09ec22>] pci_device_probe+0xe4/0x198
    [<00000000d43eca75>] really_probe+0xdc/0x320
    [<00000000d3ebab09>] driver_probe_device+0x5c/0xf0
    [<000000005b3ecaa0>] __device_attach_driver+0x88/0xc0
    [<000000004e5915f5>] bus_for_each_drv+0x7c/0xc8
    [<0000000079d4db41>] __device_attach+0xe4/0x140
    [<00000000883bbda9>] device_initial_probe+0x18/0x20
    [<000000003be59ef6>] bus_probe_device+0x98/0xa0
    [<0000000039b03d3f>] deferred_probe_work_func+0x74/0xa8
    [<00000000870934ce>] process_one_work+0x1c8/0x470
    [<00000000e3cce570>] worker_thread+0x1f8/0x428
    [<000000005d64975e>] kthread+0xfc/0x128
    [<00000000f0eaa764>] ret_from_fork+0x10/0x18

Fixes: 495c38d300 ("irqdomain: Add irq_domain_{push,pop}_irq() functions")
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200120043547.22271-1-haokexin@gmail.com
2020-01-20 19:10:05 +00:00
Jessica Yu
708e0ada19 module: avoid setting info->name early in case we can fall back to info->mod->name
In setup_load_info(), info->name (which contains the name of the module,
mostly used for early logging purposes before the module gets set up)
gets unconditionally assigned if .modinfo is missing despite the fact
that there is an if (!info->name) check near the end of the function.
Avoid assigning a placeholder string to info->name if .modinfo doesn't
exist, so that we can fall back to info->mod->name later on.

Fixes: 5fdc7db644 ("module: setup load info before module_sig_check()")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-01-20 16:59:39 +01:00
Yash Shah
b01ecceaf2 genirq: Introduce irq_domain_translate_onecell
Add a new function irq_domain_translate_onecell() that is to be used as
the translate function in struct irq_domain_ops.

Signed-off-by: Yash Shah <yash.shah@sifive.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1575976274-13487-2-git-send-email-yash.shah@sifive.com
2020-01-20 09:19:33 +00:00
Ingo Molnar
cb6c82df68 Linux 5.5-rc7
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Merge tag 'v5.5-rc7' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-20 08:43:44 +01:00
Viresh Kumar
afa70d941f sched/fair: Define sched_idle_cpu() only for SMP configurations
sched_idle_cpu() isn't used for non SMP configuration and with a recent
change, we have started getting following warning:

  kernel/sched/fair.c:5221:12: warning: ‘sched_idle_cpu’ defined but not used [-Wunused-function]

Fix that by defining sched_idle_cpu() only for SMP configurations.

Fixes: 323af6deaf ("sched/fair: Load balance aggressively for SCHED_IDLE CPUs")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/f0554f590687478b33914a4aff9f0e6a62886d44.1579499907.git.viresh.kumar@linaro.org
2020-01-20 08:03:39 +01:00
Johannes Berg
87c9366e17 Revert "um: Enable CONFIG_CONSTRUCTORS"
This reverts commit 786b2384bf ("um: Enable CONFIG_CONSTRUCTORS").

There are two issues with this commit, uncovered by Anton in tests
on some (Debian) systems:

1) I completely forgot to call any constructors if CONFIG_CONSTRUCTORS
   isn't set. Don't recall now if it just wasn't needed on my system, or
   if I never tested this case.

2) With that fixed, it works - with CONFIG_CONSTRUCTORS *unset*. If I
   set CONFIG_CONSTRUCTORS, it fails again, which isn't totally
   unexpected since whatever wanted to run is likely to have to run
   before the kernel init etc. that calls the constructors in this case.

Basically, some constructors that gcc emits (libc has?) need to run
very early during init; the failure mode otherwise was that the ptrace
fork test already failed:

----------------------
$ ./linux mem=512M
Core dump limits :
	soft - 0
	hard - NONE
Checking that ptrace can change system call numbers...check_ptrace : child exited with exitcode 6, while expecting 0; status 0x67f
Aborted
----------------------

Thinking more about this, it's clear that we simply cannot support
CONFIG_CONSTRUCTORS in UML. All the cases we need now (gcov, kasan)
involve not use of the __attribute__((constructor)), but instead
some constructor code/entry generated by gcc. Therefore, we cannot
distinguish between kernel constructors and system constructors.

Thus, revert this commit.

Cc: stable@vger.kernel.org [5.4+]
Fixes: 786b2384bf ("um: Enable CONFIG_CONSTRUCTORS")
Reported-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.co.uk>

Signed-off-by: Richard Weinberger <richard@nod.at>
2020-01-19 22:42:06 +01:00
David S. Miller
b3f7e3f23a Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net 2020-01-19 22:10:04 +01:00
Linus Torvalds
11a8272947 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Fix non-blocking connect() in x25, from Martin Schiller.

 2) Fix spurious decryption errors in kTLS, from Jakub Kicinski.

 3) Netfilter use-after-free in mtype_destroy(), from Cong Wang.

 4) Limit size of TSO packets properly in lan78xx driver, from Eric
    Dumazet.

 5) r8152 probe needs an endpoint sanity check, from Johan Hovold.

 6) Prevent looping in tcp_bpf_unhash() during sockmap/tls free, from
    John Fastabend.

 7) hns3 needs short frames padded on transmit, from Yunsheng Lin.

 8) Fix netfilter ICMP header corruption, from Eyal Birger.

 9) Fix soft lockup when low on memory in hns3, from Yonglong Liu.

10) Fix NTUPLE firmware command failures in bnxt_en, from Michael Chan.

11) Fix memory leak in act_ctinfo, from Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (91 commits)
  cxgb4: reject overlapped queues in TC-MQPRIO offload
  cxgb4: fix Tx multi channel port rate limit
  net: sched: act_ctinfo: fix memory leak
  bnxt_en: Do not treat DSN (Digital Serial Number) read failure as fatal.
  bnxt_en: Fix ipv6 RFS filter matching logic.
  bnxt_en: Fix NTUPLE firmware command failures.
  net: systemport: Fixed queue mapping in internal ring map
  net: dsa: bcm_sf2: Configure IMP port for 2Gb/sec
  net: dsa: sja1105: Don't error out on disabled ports with no phy-mode
  net: phy: dp83867: Set FORCE_LINK_GOOD to default after reset
  net: hns: fix soft lockup when there is not enough memory
  net: avoid updating qdisc_xmit_lock_key in netdev_update_lockdep_key()
  net/sched: act_ife: initalize ife->metalist earlier
  netfilter: nat: fix ICMP header corruption on ICMP errors
  net: wan: lapbether.c: Use built-in RCU list checking
  netfilter: nf_tables: fix flowtable list del corruption
  netfilter: nf_tables: fix memory leak in nf_tables_parse_netdev_hooks()
  netfilter: nf_tables: remove WARN and add NLA_STRING upper limits
  netfilter: nft_tunnel: ERSPAN_VERSION must not be null
  netfilter: nft_tunnel: fix null-attribute check
  ...
2020-01-19 12:03:53 -08:00
Linus Torvalds
7ff15cd045 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar:
 "Three fixes: fix link failure on Alpha, fix a Sparse warning and
  annotate/robustify a lockless access in the NOHZ code"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/sched: Annotate lockless access to last_jiffies_update
  lib/vdso: Make __cvdso_clock_getres() static
  time/posix-stubs: Provide compat itimer supoprt for alpha
2020-01-18 13:00:59 -08:00
Linus Torvalds
9e79c52332 Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull cpu/SMT fix from Ingo Molnar:
 "Fix a build bug on CONFIG_HOTPLUG_SMT=y && !CONFIG_SYSFS kernels"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/SMT: Fix x86 link error without CONFIG_SYSFS
2020-01-18 12:57:41 -08:00
Linus Torvalds
b07b9e8d63 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Tooling fixes, three Intel uncore driver fixes, plus an AUX events fix
  uncovered by the perf fuzzer"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/uncore: Remove PCIe3 unit for SNR
  perf/x86/intel/uncore: Fix missing marker for snr_uncore_imc_freerunning_events
  perf/x86/intel/uncore: Add PCI ID of IMC for Xeon E3 V5 Family
  perf: Correctly handle failed perf_get_aux_event()
  perf hists: Fix variable name's inconsistency in hists__for_each() macro
  perf map: Set kmap->kmaps backpointer for main kernel map chunks
  perf report: Fix incorrectly added dimensions as switch perf data file
  tools lib traceevent: Fix memory leakage in filter_event
2020-01-18 12:55:19 -08:00
Linus Torvalds
124b5547ec Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "Three fixes:

    - Fix an rwsem spin-on-owner crash, introduced in v5.4

    - Fix a lockdep bug when running out of stack_trace entries,
      introduced in v5.4

    - Docbook fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwsem: Fix kernel crash when spinning on RWSEM_OWNER_UNKNOWN
  futex: Fix kernel-doc notation warning
  locking/lockdep: Fix buffer overrun problem in stack_trace[]
2020-01-18 12:53:28 -08:00
Linus Torvalds
ba0f472203 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull rseq fixes from Ingo Molnar:
 "Two rseq bugfixes:

   - CLONE_VM !CLONE_THREAD didn't work properly, the kernel would end
     up corrupting the TLS of the parent. Technically a change in the
     ABI but the previous behavior couldn't resonably have been relied
     on by applications so this looks like a valid exception to the ABI
     rule.

   - Make the RSEQ_FLAG_UNREGISTER ABI behavior consistent with the
     handling of other flags. This is not thought to impact any
     applications either"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rseq: Unregister rseq for clone CLONE_VM
  rseq: Reject unknown flags on rseq unregister
2020-01-18 12:29:13 -08:00
Linus Torvalds
8cac89909a for-linus-2020-01-18
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Merge tag 'for-linus-2020-01-18' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull thread fixes from Christian Brauner:
 "Here is an urgent fix for ptrace_may_access() permission checking.

  Commit 69f594a389 ("ptrace: do not audit capability check when
  outputing /proc/pid/stat") introduced the ability to opt out of audit
  messages for accesses to various proc files since they are not
  violations of policy.

  While doing so it switched the check from ns_capable() to
  has_ns_capability{_noaudit}(). That means it switched from checking
  the subjective credentials (ktask->cred) of the task to using the
  objective credentials (ktask->real_cred). This is appears to be wrong.
  ptrace_has_cap() is currently only used in ptrace_may_access() And is
  used to check whether the calling task (subject) has the
  CAP_SYS_PTRACE capability in the provided user namespace to operate on
  the target task (object). According to the cred.h comments this means
  the subjective credentials of the calling task need to be used.

  With this fix we switch ptrace_has_cap() to use security_capable() and
  thus back to using the subjective credentials.

  As one example where this might be particularly problematic, Jann
  pointed out that in combination with the upcoming IORING_OP_OPENAT{2}
  feature, this bug might allow unprivileged users to bypass the
  capability checks while asynchronously opening files like /proc/*/mem,
  because the capability checks for this would be performed against
  kernel credentials.

  To illustrate on the former point about this being exploitable: When
  io_uring creates a new context it records the subjective credentials
  of the caller. Later on, when it starts to do work it creates a kernel
  thread and registers a callback. The callback runs with kernel creds
  for ktask->real_cred and ktask->cred.

  To prevent this from becoming a full-blown 0-day io_uring will call
  override_cred() and override ktask->cred with the subjective
  credentials of the creator of the io_uring instance. With
  ptrace_has_cap() currently looking at ktask->real_cred this override
  will be ineffective and the caller will be able to open arbitray proc
  files as mentioned above.

  Luckily, this is currently not exploitable but would be so once
  IORING_OP_OPENAT{2} land in v5.6. Let's fix it now.

  To minimize potential regressions I successfully ran the criu
  testsuite. criu makes heavy use of ptrace() and extensively hits
  ptrace_may_access() codepaths and has a good change of detecting any
  regressions.

  Additionally, I succesfully ran the ptrace and seccomp kernel tests"

* tag 'for-linus-2020-01-18' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  ptrace: reintroduce usage of subjective credentials in ptrace_has_cap()
2020-01-18 12:23:31 -08:00
Christian Brauner
6b3ad6649a
ptrace: reintroduce usage of subjective credentials in ptrace_has_cap()
Commit 69f594a389 ("ptrace: do not audit capability check when outputing /proc/pid/stat")
introduced the ability to opt out of audit messages for accesses to various
proc files since they are not violations of policy.  While doing so it
somehow switched the check from ns_capable() to
has_ns_capability{_noaudit}(). That means it switched from checking the
subjective credentials of the task to using the objective credentials. This
is wrong since. ptrace_has_cap() is currently only used in
ptrace_may_access() And is used to check whether the calling task (subject)
has the CAP_SYS_PTRACE capability in the provided user namespace to operate
on the target task (object). According to the cred.h comments this would
mean the subjective credentials of the calling task need to be used.
This switches ptrace_has_cap() to use security_capable(). Because we only
call ptrace_has_cap() in ptrace_may_access() and in there we already have a
stable reference to the calling task's creds under rcu_read_lock() there's
no need to go through another series of dereferences and rcu locking done
in ns_capable{_noaudit}().

As one example where this might be particularly problematic, Jann pointed
out that in combination with the upcoming IORING_OP_OPENAT feature, this
bug might allow unprivileged users to bypass the capability checks while
asynchronously opening files like /proc/*/mem, because the capability
checks for this would be performed against kernel credentials.

To illustrate on the former point about this being exploitable: When
io_uring creates a new context it records the subjective credentials of the
caller. Later on, when it starts to do work it creates a kernel thread and
registers a callback. The callback runs with kernel creds for
ktask->real_cred and ktask->cred. To prevent this from becoming a
full-blown 0-day io_uring will call override_cred() and override
ktask->cred with the subjective credentials of the creator of the io_uring
instance. With ptrace_has_cap() currently looking at ktask->real_cred this
override will be ineffective and the caller will be able to open arbitray
proc files as mentioned above.
Luckily, this is currently not exploitable but will turn into a 0-day once
IORING_OP_OPENAT{2} land in v5.6. Fix it now!

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Jann Horn <jannh@google.com>
Fixes: 69f594a389 ("ptrace: do not audit capability check when outputing /proc/pid/stat")
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-01-18 13:51:39 +01:00
Thomas Gleixner
9f24c540f7 lib/vdso: Update coarse timekeeper unconditionally
The low resolution parts of the VDSO, i.e.:

  clock_gettime(CLOCK_*_COARSE), clock_getres(), time()

can be used even if there is no VDSO capable clocksource.

But if an architecture opts out of the VDSO data update then this
information becomes stale. This affects ARM when there is no architected
timer available. The lack of update causes userspace to use stale data
forever.

Make the update of the low resolution parts unconditional and only skip
the update of the high resolution parts if the architecture requests it.

Fixes: 44f57d788e ("timekeeping: Provide a generic update_vsyscall() implementation")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200114185946.765577901@linutronix.de
2020-01-17 15:53:50 +01:00
Thomas Gleixner
9a6b55ac4a lib/vdso: Make __arch_update_vdso_data() logic understandable
The function name suggests that this is a boolean checking whether the
architecture asks for an update of the VDSO data, but it works the other
way round. To spare further confusion invert the logic.

Fixes: 44f57d788e ("timekeeping: Provide a generic update_vsyscall() implementation")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200114185946.656652824@linutronix.de
2020-01-17 15:53:50 +01:00
Mark Rutland
da9ec3d3dd perf: Correctly handle failed perf_get_aux_event()
Vince reports a worrying issue:

| so I was tracking down some odd behavior in the perf_fuzzer which turns
| out to be because perf_even_open() sometimes returns 0 (indicating a file
| descriptor of 0) even though as far as I can tell stdin is still open.

... and further the cause:

| error is triggered if aux_sample_size has non-zero value.
|
| seems to be this line in kernel/events/core.c:
|
| if (perf_need_aux_event(event) && !perf_get_aux_event(event, group_leader))
|                goto err_locked;
|
| (note, err is never set)

This seems to be a thinko in commit:

  ab43762ef0 ("perf: Allow normal events to output AUX data")

... and we should probably return -EINVAL here, as this should only
happen when the new event is mis-configured or does not have a
compatible aux_event group leader.

Fixes: ab43762ef0 ("perf: Allow normal events to output AUX data")
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
2020-01-17 11:32:44 +01:00
Thomas Gleixner
11e31f608b watchdog/softlockup: Enforce that timestamp is valid on boot
Robert reported that during boot the watchdog timestamp is set to 0 for one
second which is the indicator for a watchdog reset.

The reason for this is that the timestamp is in seconds and the time is
taken from sched clock and divided by ~1e9. sched clock starts at 0 which
means that for the first second during boot the watchdog timestamp is 0,
i.e. reset.

Use ULONG_MAX as the reset indicator value so the watchdog works correctly
right from the start. ULONG_MAX would only conflict with a real timestamp
if the system reaches an uptime of 136 years on 32bit and almost eternity
on 64bit.

Reported-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/87o8v3uuzl.fsf@nanos.tec.linutronix.de
2020-01-17 11:19:22 +01:00
Waiman Long
f5bfdc8e39 locking/osq: Use optimized spinning loop for arm64
Arm64 has a more optimized spinning loop (atomic_cond_read_acquire)
using wfe for spinlock that can boost performance of sibling threads
by putting the current cpu to a wait state that is broken only when
the monitored variable changes or an external event happens.

OSQ has a more complicated spinning loop. Besides the lock value, it
also checks for need_resched() and vcpu_is_preempted(). The check for
need_resched() is not a problem as it is only set by the tick interrupt
handler. That will be detected by the spinning cpu right after iret.

The vcpu_is_preempted() check, however, is a problem as changes to the
preempt state of of previous node will not affect the wait state. For
ARM64, vcpu_is_preempted is not currently defined and so is a no-op.
Will has indicated that he is planning to para-virtualize wfe instead
of defining vcpu_is_preempted for PV support. So just add a comment in
arch/arm64/include/asm/spinlock.h to indicate that vcpu_is_preempted()
should not be defined as suggested.

On a 2-socket 56-core 224-thread ARM64 system, a kernel mutex locking
microbenchmark was run for 10s with and without the patch. The
performance numbers before patch were:

Running locktest with mutex [runtime = 10s, load = 1]
Threads = 224, Min/Mean/Max = 316/123,143/2,121,269
Threads = 224, Total Rate = 2,757 kop/s; Percpu Rate = 12 kop/s

After patch, the numbers were:

Running locktest with mutex [runtime = 10s, load = 1]
Threads = 224, Min/Mean/Max = 334/147,836/1,304,787
Threads = 224, Total Rate = 3,311 kop/s; Percpu Rate = 15 kop/s

So there was about 20% performance improvement.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20200113150735.21956-1-longman@redhat.com
2020-01-17 10:19:30 +01:00
Waiman Long
57097124cb locking/qspinlock: Fix inaccessible URL of MCS lock paper
It turns out that the URL of the MCS lock paper listed in the source
code is no longer accessible. I did got question about where the paper
was. This patch updates the URL to BZ 206115 which contains a copy of
the paper from

  https://www.cs.rochester.edu/u/scott/papers/1991_TOCS_synch.pdf

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20200107174914.4187-1-longman@redhat.com
2020-01-17 10:19:30 +01:00
Waiman Long
a030f9767d locking/lockdep: Fix lockdep_stats indentation problem
It was found that two lines in the output of /proc/lockdep_stats have
indentation problem:

  # cat /proc/lockdep_stats
     :
   in-process chains:                   25057
   stack-trace entries:                137827 [max: 524288]
   number of stack traces:        7973
   number of stack hash chains:   6355
   combined max dependencies:      1356414598
   hardirq-safe locks:                     57
   hardirq-unsafe locks:                 1286
     :

All the numbers displayed in /proc/lockdep_stats except the two stack
trace numbers are formatted with a field with of 11. To properly align
all the numbers, a field width of 11 is now added to the two stack
trace numbers.

Fixes: 8c779229d0 ("locking/lockdep: Report more stack trace statistics")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lkml.kernel.org/r/20191211213139.29934-1-longman@redhat.com
2020-01-17 10:19:30 +01:00
Waiman Long
39e7234f00 locking/rwsem: Fix kernel crash when spinning on RWSEM_OWNER_UNKNOWN
The commit 91d2a812df ("locking/rwsem: Make handoff writer
optimistically spin on owner") will allow a recently woken up waiting
writer to spin on the owner. Unfortunately, if the owner happens to be
RWSEM_OWNER_UNKNOWN, the code will incorrectly spin on it leading to a
kernel crash. This is fixed by passing the proper non-spinnable bits
to rwsem_spin_on_owner() so that RWSEM_OWNER_UNKNOWN will be treated
as a non-spinnable target.

Fixes: 91d2a812df ("locking/rwsem: Make handoff writer optimistically spin on owner")

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200115154336.8679-1-longman@redhat.com
2020-01-17 10:19:27 +01:00
Valentin Schneider
ccf74128d6 sched/topology: Assert non-NUMA topology masks don't (partially) overlap
topology.c::get_group() relies on the assumption that non-NUMA domains do
not partially overlap. Zeng Tao pointed out in [1] that such topology
descriptions, while completely bogus, can end up being exposed to the
scheduler.

In his example (8 CPUs, 2-node system), we end up with:
  MC span for CPU3 == 3-7
  MC span for CPU4 == 4-7

The first pass through get_group(3, sdd@MC) will result in the following
sched_group list:

  3 -> 4 -> 5 -> 6 -> 7
  ^                  /
   `----------------'

And a later pass through get_group(4, sdd@MC) will "corrupt" that to:

  3 -> 4 -> 5 -> 6 -> 7
       ^             /
	`-----------'

which will completely break things like 'while (sg != sd->groups)' when
using CPU3's base sched_domain.

There already are some architecture-specific checks in place such as
x86/kernel/smpboot.c::topology.sane(), but this is something we can detect
in the core scheduler, so it seems worthwhile to do so.

Warn and abort the construction of the sched domains if such a broken
topology description is detected. Note that this is somewhat
expensive (O(t.c²), 't' non-NUMA topology levels and 'c' CPUs) and could be
gated under SCHED_DEBUG if deemed necessary.

Testing
=======

Dietmar managed to reproduce this using the following qemu incantation:

  $ qemu-system-aarch64 -kernel ./Image -hda ./qemu-image-aarch64.img \
  -append 'root=/dev/vda console=ttyAMA0 loglevel=8 sched_debug' -smp \
  cores=8 --nographic -m 512 -cpu cortex-a53 -machine virt -numa \
  node,cpus=0-2,nodeid=0 -numa node,cpus=3-7,nodeid=1

alongside the following drivers/base/arch_topology.c hack (AIUI wouldn't be
needed if '-smp cores=X, sockets=Y' would work with qemu):

8<---
@@ -465,6 +465,9 @@ void update_siblings_masks(unsigned int cpuid)
 		if (cpuid_topo->package_id != cpu_topo->package_id)
 			continue;

+		if ((cpu < 4 && cpuid > 3) || (cpu > 3 && cpuid < 4))
+			continue;
+
 		cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
 		cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);

8<---

[1]: https://lkml.kernel.org/r/1577088979-8545-1-git-send-email-prime.zeng@hisilicon.com

Reported-by: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200115160915.22575-1-valentin.schneider@arm.com
2020-01-17 10:19:23 +01:00
Hewenliang
3e0de271ff idle: fix spelling mistake "iterrupts" -> "interrupts"
There is a spelling misake in comments of cpuidle_idle_call. Fix it.

Signed-off-by: Hewenliang <hewenliang4@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20200110025604.34373-1-hewenliang4@huawei.com
2020-01-17 10:19:22 +01:00
Vincent Guittot
a4f9a0e51b sched/fair: Remove redundant call to cpufreq_update_util()
With commit

  bef69dd878 ("sched/cpufreq: Move the cfs_rq_util_change() call to cpufreq_update_util()")

update_load_avg() has become the central point for calling cpufreq
(not including the update of blocked load). This change helps to
simplify further the number of calls to cpufreq_update_util() and to
remove last redundant ones. With update_load_avg(), we are now sure
that cpufreq_update_util() will be called after every task attachment
to a cfs_rq and especially after propagating this event down to the
util_avg of the root cfs_rq, which is the level that is used by
cpufreq governors like schedutil to set the frequency of a CPU.

The SCHED_CPUFREQ_MIGRATION flag forces an early call to cpufreq when
the migration happens in a cgroup whereas util_avg of root cfs_rq is
not yet updated and this call is duplicated with the one that happens
immediately after when the migration event reaches the root cfs_rq.
The dedicated flag SCHED_CPUFREQ_MIGRATION is now useless and can be
removed. The interface of attach_entity_load_avg() can also be
simplified accordingly.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/1579083620-24943-1-git-send-email-vincent.guittot@linaro.org
2020-01-17 10:19:22 +01:00
Wang Long
3d817689a6 sched/psi: create /proc/pressure and /proc/pressure/{io|memory|cpu} only when psi enabled
when CONFIG_PSI_DEFAULT_DISABLED set to N or the command line set psi=0,
I think we should not create /proc/pressure and
/proc/pressure/{io|memory|cpu}.

In the future, user maybe determine whether the psi feature is enabled by
checking the existence of the /proc/pressure dir or
/proc/pressure/{io|memory|cpu} files.

Signed-off-by: Wang Long <w@laoqinren.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lkml.kernel.org/r/1576672698-32504-1-git-send-email-w@laoqinren.net
2020-01-17 10:19:22 +01:00
Peng Liu
4c58f57fa6 sched/fair: Fix sgc->{min,max}_capacity calculation for SD_OVERLAP
commit bf475ce0a3 ("sched/fair: Add per-CPU min capacity to
sched_group_capacity") introduced per-cpu min_capacity.

commit e3d6d0cb66 ("sched/fair: Add sched_group per-CPU max capacity")
introduced per-cpu max_capacity.

In the SD_OVERLAP case, the local variable 'capacity' represents the sum
of CPU capacity of all CPUs in the first sched group (sg) of the sched
domain (sd).

It is erroneously used to calculate sg's min and max CPU capacity.
To fix this use capacity_of(cpu) instead of 'capacity'.

The code which achieves this via cpu_rq(cpu)->sd->groups->sgc->capacity
(for rq->sd != NULL) can be removed since it delivers the same value as
capacity_of(cpu) which is currently only used for the (!rq->sd) case
(see update_cpu_capacity()).
An sg of the lowest sd (rq->sd or sd->child == NULL) represents a single
CPU (and hence sg->sgc->capacity == capacity_of(cpu)).

Signed-off-by: Peng Liu <iwtbavbm@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20200104130828.GA7718@iZj6chx1xj0e0buvshuecpZ
2020-01-17 10:19:21 +01:00
Peng Wang
fe71bbb21e sched/fair: calculate delta runnable load only when it's needed
Move the code of calculation for delta_sum/delta_avg to where
it is really needed to be done.

Signed-off-by: Peng Wang <rocking@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20200103114400.17668-1-rocking@linux.alibaba.com
2020-01-17 10:19:21 +01:00
Alex Shi
9dec1b6949 sched/cputime: move rq parameter in irqtime_account_process_tick
Every time we call irqtime_account_process_tick() is in a interrupt,
Every caller will get and assign a parameter rq = this_rq(), This is
unnecessary and increase the code size a little bit. Move the rq getting
action to irqtime_account_process_tick internally is better.

             base               with this patch
cputime.o    578792 bytes        577888 bytes

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1577959674-255537-1-git-send-email-alex.shi@linux.alibaba.com
2020-01-17 10:19:21 +01:00
Yangtao Li
35f4cd96f5 stop_machine: Make stop_cpus() static
The function stop_cpus() is only used internally by the
stop_machine for stop multiple cpus.

Make it static.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20191228161912.24082-1-tiny.windzz@gmail.com
2020-01-17 10:19:21 +01:00
Wei Li
02d4ac5885 sched/debug: Reset watchdog on all CPUs while processing sysrq-t
Lengthy output of sysrq-t may take a lot of time on slow serial console
with lots of processes and CPUs.

So we need to reset NMI-watchdog to avoid spurious lockup messages, and
we also reset softlockup watchdogs on all other CPUs since another CPU
might be blocked waiting for us to process an IPI or stop_machine.

Add to sysrq_sched_debug_show() as what we did in show_state_filter().

Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20191226085224.48942-1-liwei391@huawei.com
2020-01-17 10:19:20 +01:00
Li Guanglei
dcd6dffb0a sched/core: Fix size of rq::uclamp initialization
rq::uclamp is an array of struct uclamp_rq, make sure we clear the
whole thing.

Fixes: 69842cba9a ("sched/uclamp: Add CPU's clamp buckets refcountinga")
Signed-off-by: Li Guanglei <guanglei.li@unisoc.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Qais Yousef <qais.yousef@arm.com>
Link: https://lkml.kernel.org/r/1577259844-12677-1-git-send-email-guangleix.li@gmail.com
2020-01-17 10:19:20 +01:00
Qais Yousef
7226017ad3 sched/uclamp: Fix a bug in propagating uclamp value in new cgroups
When a new cgroup is created, the effective uclamp value wasn't updated
with a call to cpu_util_update_eff() that looks at the hierarchy and
update to the most restrictive values.

Fix it by ensuring to call cpu_util_update_eff() when a new cgroup
becomes online.

Without this change, the newly created cgroup uses the default
root_task_group uclamp values, which is 1024 for both uclamp_{min, max},
which will cause the rq to to be clamped to max, hence cause the
system to run at max frequency.

The problem was observed on Ubuntu server and was reproduced on Debian
and Buildroot rootfs.

By default, Ubuntu and Debian create a cpu controller cgroup hierarchy
and add all tasks to it - which creates enough noise to keep the rq
uclamp value at max most of the time. Imitating this behavior makes the
problem visible in Buildroot too which otherwise looks fine since it's a
minimal userspace.

Fixes: 0b60ba2dd3 ("sched/uclamp: Propagate parent clamps")
Reported-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Doug Smythies <dsmythies@telus.net>
Link: https://lore.kernel.org/lkml/000701d5b965$361b6c60$a2524520$@net/
2020-01-17 10:19:20 +01:00
Viresh Kumar
323af6deaf sched/fair: Load balance aggressively for SCHED_IDLE CPUs
The fair scheduler performs periodic load balance on every CPU to check
if it can pull some tasks from other busy CPUs. The duration of this
periodic load balance is set to sd->balance_interval for the idle CPUs
and is calculated by multiplying the sd->balance_interval with the
sd->busy_factor (set to 32 by default) for the busy CPUs. The
multiplication is done for busy CPUs to avoid doing load balance too
often and rather spend more time executing actual task. While that is
the right thing to do for the CPUs busy with SCHED_OTHER or SCHED_BATCH
tasks, it may not be the optimal thing for CPUs running only SCHED_IDLE
tasks.

With the recent enhancements in the fair scheduler around SCHED_IDLE
CPUs, we now prefer to enqueue a newly-woken task to a SCHED_IDLE
CPU instead of other busy or idle CPUs. The same reasoning should be
applied to the load balancer as well to make it migrate tasks more
aggressively to a SCHED_IDLE CPU, as that will reduce the scheduling
latency of the migrated (SCHED_OTHER) tasks.

This patch makes minimal changes to the fair scheduler to do the next
load balance soon after the last non SCHED_IDLE task is dequeued from a
runqueue, i.e. making the CPU SCHED_IDLE. Also the sd->busy_factor is
ignored while calculating the balance_interval for such CPUs. This is
done to avoid delaying the periodic load balance by few hundred
milliseconds for SCHED_IDLE CPUs.

This is tested on ARM64 Hikey620 platform (octa-core) with the help of
rt-app and it is verified, using kernel traces, that the newly
SCHED_IDLE CPU does load balancing shortly after it becomes SCHED_IDLE
and pulls tasks from other busy CPUs.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/e485827eb8fe7db0943d6f3f6e0f5a4a70272781.1578471925.git.viresh.kumar@linaro.org
2020-01-17 10:19:20 +01:00
Vincent Guittot
5f68eb19b5 sched/fair : Improve update_sd_pick_busiest for spare capacity case
Similarly to calculate_imbalance() and find_busiest_group(), using the
number of idle CPUs when there is only 1 CPU in the group is not efficient
because we can't make a difference between a CPU running 1 task and a CPU
running dozens of small tasks competing for the same CPU but not enough
to overload it. More generally speaking, we should use the number of
running tasks when there is the same number of idle CPUs in a group instead
of blindly select the 1st one.

When the groups have spare capacity and the same number of idle CPUs, we
compare the number of running tasks to select the busiest group.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1576839893-26930-1-git-send-email-vincent.guittot@linaro.org
2020-01-17 10:19:19 +01:00
Jisheng Zhang
db5793c599 watchdog: Remove soft_lockup_hrtimer_cnt and related code
After commit 9cf57731b6 ("watchdog/softlockup: Replace "watchdog/%u"
threads with cpu_stop_work"), the percpu soft_lockup_hrtimer_cnt is
not used any more, so remove it and related code.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20191218131720.4146aea2@xhacker.debian
2020-01-17 10:19:19 +01:00
Steven Rostedt (VMware)
31537cf8f3 tracing: Initialize ret in syscall_enter_define_fields()
If syscall_enter_define_fields() is called on a system call with no
arguments, the return code variable "ret" will never get initialized.
Initialize it to zero.

Fixes: 04ae87a520 ("ftrace: Rework event_create_dir()")
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/0FA8C6E3-D9F5-416D-A1B0-5E4CD583A101@lca.pw
2020-01-17 10:19:18 +01:00
YueHaibing
81f2b572cf bpf: Remove set but not used variable 'first_key'
kernel/bpf/syscall.c: In function generic_map_lookup_batch:
kernel/bpf/syscall.c:1339:7: warning: variable first_key set but not used [-Wunused-but-set-variable]

It is never used, so remove it.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Brian Vazquez <brianvv@google.com>
Link: https://lore.kernel.org/bpf/20200116145300.59056-1-yuehaibing@huawei.com
2020-01-16 20:15:24 -08:00
Jesper Dangaard Brouer
58aa94f922 devmap: Adjust tracepoint for map-less queue flush
Now that we don't have a reference to a devmap when flushing the device
bulk queue, let's change the the devmap_xmit tracepoint to remote the
map_id and map_index fields entirely. Rearrange the fields so 'drops' and
'sent' stay in the same position in the tracepoint struct, to make it
possible for the xdp_monitor utility to read both the old and the new
format.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/157918768613.1458396.9165902403373826572.stgit@toke.dk
2020-01-16 20:03:34 -08:00
Toke Høiland-Jørgensen
1d233886dd xdp: Use bulking for non-map XDP_REDIRECT and consolidate code paths
Since the bulk queue used by XDP_REDIRECT now lives in struct net_device,
we can re-use the bulking for the non-map version of the bpf_redirect()
helper. This is a simple matter of having xdp_do_redirect_slow() queue the
frame on the bulk queue instead of sending it out with __bpf_tx_xdp().

Unfortunately we can't make the bpf_redirect() helper return an error if
the ifindex doesn't exit (as bpf_redirect_map() does), because we don't
have a reference to the network namespace of the ingress device at the time
the helper is called. So we have to leave it as-is and keep the device
lookup in xdp_do_redirect_slow().

Since this leaves less reason to have the non-map redirect code in a
separate function, so we get rid of the xdp_do_redirect_slow() function
entirely. This does lose us the tracepoint disambiguation, but fortunately
the xdp_redirect and xdp_redirect_map tracepoints use the same tracepoint
entry structures. This means both can contain a map index, so we can just
amend the tracepoint definitions so we always emit the xdp_redirect(_err)
tracepoints, but with the map ID only populated if a map is present. This
means we retire the xdp_redirect_map(_err) tracepoints entirely, but keep
the definitions around in case someone is still listening for them.

With this change, the performance of the xdp_redirect sample program goes
from 5Mpps to 8.4Mpps (a 68% increase).

Since the flush functions are no longer map-specific, rename the flush()
functions to drop _map from their names. One of the renamed functions is
the xdp_do_flush_map() callback used in all the xdp-enabled drivers. To
keep from having to update all drivers, use a #define to keep the old name
working, and only update the virtual drivers in this patch.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/157918768505.1458396.17518057312953572912.stgit@toke.dk
2020-01-16 20:03:34 -08:00
Toke Høiland-Jørgensen
75ccae62cb xdp: Move devmap bulk queue into struct net_device
Commit 96360004b8 ("xdp: Make devmap flush_list common for all map
instances"), changed devmap flushing to be a global operation instead of a
per-map operation. However, the queue structure used for bulking was still
allocated as part of the containing map.

This patch moves the devmap bulk queue into struct net_device. The
motivation for this is reusing it for the non-map variant of XDP_REDIRECT,
which will be changed in a subsequent commit.  To avoid other fields of
struct net_device moving to different cache lines, we also move a couple of
other members around.

We defer the actual allocation of the bulk queue structure until the
NETDEV_REGISTER notification devmap.c. This makes it possible to check for
ndo_xdp_xmit support before allocating the structure, which is not possible
at the time struct net_device is allocated. However, we keep the freeing in
free_netdev() to avoid adding another RCU callback on NETDEV_UNREGISTER.

Because of this change, we lose the reference back to the map that
originated the redirect, so change the tracepoint to always return 0 as the
map ID and index. Otherwise no functional change is intended with this
patch.

After this patch, the relevant part of struct net_device looks like this,
according to pahole:

	/* --- cacheline 14 boundary (896 bytes) --- */
	struct netdev_queue *      _tx __attribute__((__aligned__(64))); /*   896     8 */
	unsigned int               num_tx_queues;        /*   904     4 */
	unsigned int               real_num_tx_queues;   /*   908     4 */
	struct Qdisc *             qdisc;                /*   912     8 */
	unsigned int               tx_queue_len;         /*   920     4 */
	spinlock_t                 tx_global_lock;       /*   924     4 */
	struct xdp_dev_bulk_queue * xdp_bulkq;           /*   928     8 */
	struct xps_dev_maps *      xps_cpus_map;         /*   936     8 */
	struct xps_dev_maps *      xps_rxqs_map;         /*   944     8 */
	struct mini_Qdisc *        miniq_egress;         /*   952     8 */
	/* --- cacheline 15 boundary (960 bytes) --- */
	struct hlist_head  qdisc_hash[16];               /*   960   128 */
	/* --- cacheline 17 boundary (1088 bytes) --- */
	struct timer_list  watchdog_timer;               /*  1088    40 */

	/* XXX last struct has 4 bytes of padding */

	int                        watchdog_timeo;       /*  1128     4 */

	/* XXX 4 bytes hole, try to pack */

	struct list_head   todo_list;                    /*  1136    16 */
	/* --- cacheline 18 boundary (1152 bytes) --- */

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/157918768397.1458396.12673224324627072349.stgit@toke.dk
2020-01-16 20:03:34 -08:00
Alexander Potapenko
18451f9f9e PM: hibernate: fix crashes with init_on_free=1
Upon resuming from hibernation, free pages may contain stale data from
the kernel that initiated the resume. This breaks the invariant
inflicted by init_on_free=1 that freed pages must be zeroed.

To deal with this problem, make clear_free_pages() also clear the free
pages when init_on_free is enabled.

Fixes: 6471384af2 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options")
Reported-by: Johannes Stezenbach <js@sig21.net>
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: 5.3+ <stable@vger.kernel.org> # 5.3+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-01-16 23:51:45 +01:00
Jonas Meurer
c052bf82c6 PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior
The sysfs attribute `/sys/power/sync_on_suspend` controls, whether or not
filesystems are synced by the kernel before system suspend.

Congruously, the behaviour of build-time switch CONFIG_SUSPEND_SKIP_SYNC
is slightly changed: It now defines the run-tim default for the new sysfs
attribute `/sys/power/sync_on_suspend`.

The run-time attribute is added because the existing corresponding
build-time Kconfig flag for (`CONFIG_SUSPEND_SKIP_SYNC`) is not flexible
enough. E.g. Linux distributions that provide pre-compiled kernels
usually want to stick with the default (sync filesystems before suspend)
but under special conditions this needs to be changed.

One example for such a special condition is user-space handling of
suspending block devices (e.g. using `cryptsetup luksSuspend` or `dmsetup
suspend`) before system suspend. The Kernel trying to sync filesystems
after the underlying block device already got suspended obviously leads
to dead-locks. Be aware that you have to take care of the filesystem sync
yourself before suspending the system in those scenarios.

Signed-off-by: Jonas Meurer <jonas@freesources.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-01-16 21:47:03 +01:00
Petr Mladek
3a51449b79 watchdog/softlockup: Remove obsolete check of last reported task
commit 9cf57731b6 ("watchdog/softlockup: Replace "watchdog/%u" threads
 with cpu_stop_work") ensures that the watchdog is reliably touched during
a task switch.

As a result the check for an unnoticed task switch is not longer needed.

Remove the relevant code, which effectively reverts commit b1a8de1f53
("softlockup: make detector be aware of task switch of processes hogging
cpu")

Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Ziljstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20191024114928.15377-2-pmladek@suse.com
2020-01-16 14:52:48 +01:00
Steven Rostedt (VMware)
82d1b8158c tracing: Allow trace_printk() to nest in other tracing code
trace_printk() is used to debug the kernel which includes the tracing
infrastructure. But because it writes to the ring buffer, and so does much
of the tracing infrastructure, the ring buffer's recursive detection will
drop writes to the ring buffer that is in the same context as the current
write is happening (it allows interrupts to write when normal context is
writing, but wont let normal context write while normal context is writing).

This can cause confusion and think that the code is where the trace_printk()
exists is not hit. To solve this, up the recursive nesting of the ring
buffer when trace_printk() is called before it writes to the buffer itself.

Note, this does make it dangerous to use trace_printk() in the ring buffer
code itself, because this basically disables the recursion protection of
trace_printk() buffer writes. But as trace_printk() is only used for
debugging, and if this does occur, the developer will see the cause real
quick (recursive blowing up of the stack). Thus the developer can deal with
that. But having trace_printk() silently ignored is a much bigger problem,
and disabling recursive protection is a small price to pay to fix it.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-16 08:20:18 -05:00
Jisheng Zhang
d129479f1f watchdog: Remove soft_lockup_hrtimer_cnt and related code
After commit 9cf57731b6 ("watchdog/softlockup: Replace "watchdog/%u"
threads with cpu_stop_work"), the percpu soft_lockup_hrtimer_cnt is
not used any more, so remove it and related code.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191218131720.4146aea2@xhacker.debian
2020-01-16 12:25:51 +01:00
David S. Miller
3981f955eb Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2020-01-15

The following pull-request contains BPF updates for your *net* tree.

We've added 12 non-merge commits during the last 9 day(s) which contain
a total of 13 files changed, 95 insertions(+), 43 deletions(-).

The main changes are:

1) Fix refcount leak for TCP time wait and request sockets for socket lookup
   related BPF helpers, from Lorenz Bauer.

2) Fix wrong verification of ARSH instruction under ALU32, from Daniel Borkmann.

3) Batch of several sockmap and related TLS fixes found while operating
   more complex BPF programs with Cilium and OpenSSL, from John Fastabend.

4) Fix sockmap to read psock's ingress_msg queue before regular sk_receive_queue()
   to avoid purging data upon teardown, from Lingpeng Chen.

5) Fix printing incorrect pointer in bpftool's btf_dump_ptr() in order to properly
   dump a BPF map's value with BTF, from Martin KaFai Lau.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-16 10:04:40 +01:00
Yonghong Song
057996380a bpf: Add batch ops to all htab bpf map
htab can't use generic batch support due some problematic behaviours
inherent to the data structre, i.e. while iterating the bpf map  a
concurrent program might delete the next entry that batch was about to
use, in that case there's no easy solution to retrieve the next entry,
the issue has been discussed multiple times (see [1] and [2]).

The only way hmap can be traversed without the problem previously
exposed is by making sure that the map is traversing entire buckets.
This commit implements those strict requirements for hmap, the
implementation follows the same interaction that generic support with
some exceptions:

 - If keys/values buffer are not big enough to traverse a bucket,
   ENOSPC will be returned.
 - out_batch contains the value of the next bucket in the iteration, not
   the next key, but this is transparent for the user since the user
   should never use out_batch for other than bpf batch syscalls.

This commits implements BPF_MAP_LOOKUP_BATCH and adds support for new
command BPF_MAP_LOOKUP_AND_DELETE_BATCH. Note that for update/delete
batch ops it is possible to use the generic implementations.

[1] https://lore.kernel.org/bpf/20190724165803.87470-1-brianvv@google.com/
[2] https://lore.kernel.org/bpf/20190906225434.3635421-1-yhs@fb.com/

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115184308.162644-6-brianvv@google.com
2020-01-15 14:00:35 -08:00
Brian Vazquez
c60f2d2861 bpf: Add lookup and update batch ops to arraymap
This adds the generic batch ops functionality to bpf arraymap, note that
since deletion is not a valid operation for arraymap, only batch and
lookup are added.

Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200115184308.162644-5-brianvv@google.com
2020-01-15 14:00:35 -08:00
Brian Vazquez
aa2e93b8e5 bpf: Add generic support for update and delete batch ops
This commit adds generic support for update and delete batch ops that
can be used for almost all the bpf maps. These commands share the same
UAPI attr that lookup and lookup_and_delete batch ops use and the
syscall commands are:

  BPF_MAP_UPDATE_BATCH
  BPF_MAP_DELETE_BATCH

The main difference between update/delete and lookup batch ops is that
for update/delete keys/values must be specified for userspace and
because of that, neither in_batch nor out_batch are used.

Suggested-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115184308.162644-4-brianvv@google.com
2020-01-15 14:00:35 -08:00
Brian Vazquez
cb4d03ab49 bpf: Add generic support for lookup batch op
This commit introduces generic support for the bpf_map_lookup_batch.
This implementation can be used by almost all the bpf maps since its core
implementation is relying on the existing map_get_next_key and
map_lookup_elem. The bpf syscall subcommand introduced is:

  BPF_MAP_LOOKUP_BATCH

The UAPI attribute is:

  struct { /* struct used by BPF_MAP_*_BATCH commands */
         __aligned_u64   in_batch;       /* start batch,
                                          * NULL to start from beginning
                                          */
         __aligned_u64   out_batch;      /* output: next start batch */
         __aligned_u64   keys;
         __aligned_u64   values;
         __u32           count;          /* input/output:
                                          * input: # of key/value
                                          * elements
                                          * output: # of filled elements
                                          */
         __u32           map_fd;
         __u64           elem_flags;
         __u64           flags;
  } batch;

in_batch/out_batch are opaque values use to communicate between
user/kernel space, in_batch/out_batch must be of key_size length.

To start iterating from the beginning in_batch must be null,
count is the # of key/value elements to retrieve. Note that the 'keys'
buffer must be a buffer of key_size * count size and the 'values' buffer
must be value_size * count, where value_size must be aligned to 8 bytes
by userspace if it's dealing with percpu maps. 'count' will contain the
number of keys/values successfully retrieved. Note that 'count' is an
input/output variable and it can contain a lower value after a call.

If there's no more entries to retrieve, ENOENT will be returned. If error
is ENOENT, count might be > 0 in case it copied some values but there were
no more entries to retrieve.

Note that if the return code is an error and not -EFAULT,
count indicates the number of elements successfully processed.

Suggested-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115184308.162644-3-brianvv@google.com
2020-01-15 14:00:35 -08:00
Brian Vazquez
15c14a3dca bpf: Add bpf_map_{value_size, update_value, map_copy_value} functions
This commit moves reusable code from map_lookup_elem and map_update_elem
to avoid code duplication in kernel/bpf/syscall.c.

Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200115184308.162644-2-brianvv@google.com
2020-01-15 14:00:34 -08:00
Daniel Borkmann
0af2ffc93a bpf: Fix incorrect verifier simulation of ARSH under ALU32
Anatoly has been fuzzing with kBdysch harness and reported a hang in one
of the outcomes:

  0: R1=ctx(id=0,off=0,imm=0) R10=fp0
  0: (85) call bpf_get_socket_cookie#46
  1: R0_w=invP(id=0) R10=fp0
  1: (57) r0 &= 808464432
  2: R0_w=invP(id=0,umax_value=808464432,var_off=(0x0; 0x30303030)) R10=fp0
  2: (14) w0 -= 810299440
  3: R0_w=invP(id=0,umax_value=4294967295,var_off=(0xcf800000; 0x3077fff0)) R10=fp0
  3: (c4) w0 s>>= 1
  4: R0_w=invP(id=0,umin_value=1740636160,umax_value=2147221496,var_off=(0x67c00000; 0x183bfff8)) R10=fp0
  4: (76) if w0 s>= 0x30303030 goto pc+216
  221: R0_w=invP(id=0,umin_value=1740636160,umax_value=2147221496,var_off=(0x67c00000; 0x183bfff8)) R10=fp0
  221: (95) exit
  processed 6 insns (limit 1000000) [...]

Taking a closer look, the program was xlated as follows:

  # ./bpftool p d x i 12
  0: (85) call bpf_get_socket_cookie#7800896
  1: (bf) r6 = r0
  2: (57) r6 &= 808464432
  3: (14) w6 -= 810299440
  4: (c4) w6 s>>= 1
  5: (76) if w6 s>= 0x30303030 goto pc+216
  6: (05) goto pc-1
  7: (05) goto pc-1
  8: (05) goto pc-1
  [...]
  220: (05) goto pc-1
  221: (05) goto pc-1
  222: (95) exit

Meaning, the visible effect is very similar to f54c7898ed ("bpf: Fix
precision tracking for unbounded scalars"), that is, the fall-through
branch in the instruction 5 is considered to be never taken given the
conclusion from the min/max bounds tracking in w6, and therefore the
dead-code sanitation rewrites it as goto pc-1. However, real-life input
disagrees with verification analysis since a soft-lockup was observed.

The bug sits in the analysis of the ARSH. The definition is that we shift
the target register value right by K bits through shifting in copies of
its sign bit. In adjust_scalar_min_max_vals(), we do first coerce the
register into 32 bit mode, same happens after simulating the operation.
However, for the case of simulating the actual ARSH, we don't take the
mode into account and act as if it's always 64 bit, but location of sign
bit is different:

  dst_reg->smin_value >>= umin_val;
  dst_reg->smax_value >>= umin_val;
  dst_reg->var_off = tnum_arshift(dst_reg->var_off, umin_val);

Consider an unknown R0 where bpf_get_socket_cookie() (or others) would
for example return 0xffff. With the above ARSH simulation, we'd see the
following results:

  [...]
  1: R1=ctx(id=0,off=0,imm=0) R2_w=invP65535 R10=fp0
  1: (85) call bpf_get_socket_cookie#46
  2: R0_w=invP(id=0) R10=fp0
  2: (57) r0 &= 808464432
    -> R0_runtime = 0x3030
  3: R0_w=invP(id=0,umax_value=808464432,var_off=(0x0; 0x30303030)) R10=fp0
  3: (14) w0 -= 810299440
    -> R0_runtime = 0xcfb40000
  4: R0_w=invP(id=0,umax_value=4294967295,var_off=(0xcf800000; 0x3077fff0)) R10=fp0
                              (0xffffffff)
  4: (c4) w0 s>>= 1
    -> R0_runtime = 0xe7da0000
  5: R0_w=invP(id=0,umin_value=1740636160,umax_value=2147221496,var_off=(0x67c00000; 0x183bfff8)) R10=fp0
                              (0x67c00000)           (0x7ffbfff8)
  [...]

In insn 3, we have a runtime value of 0xcfb40000, which is '1100 1111 1011
0100 0000 0000 0000 0000', the result after the shift has 0xe7da0000 that
is '1110 0111 1101 1010 0000 0000 0000 0000', where the sign bit is correctly
retained in 32 bit mode. In insn4, the umax was 0xffffffff, and changed into
0x7ffbfff8 after the shift, that is, '0111 1111 1111 1011 1111 1111 1111 1000'
and means here that the simulation didn't retain the sign bit. With above
logic, the updates happen on the 64 bit min/max bounds and given we coerced
the register, the sign bits of the bounds are cleared as well, meaning, we
need to force the simulation into s32 space for 32 bit alu mode.

Verification after the fix below. We're first analyzing the fall-through branch
on 32 bit signed >= test eventually leading to rejection of the program in this
specific case:

  0: R1=ctx(id=0,off=0,imm=0) R10=fp0
  0: (b7) r2 = 808464432
  1: R1=ctx(id=0,off=0,imm=0) R2_w=invP808464432 R10=fp0
  1: (85) call bpf_get_socket_cookie#46
  2: R0_w=invP(id=0) R10=fp0
  2: (bf) r6 = r0
  3: R0_w=invP(id=0) R6_w=invP(id=0) R10=fp0
  3: (57) r6 &= 808464432
  4: R0_w=invP(id=0) R6_w=invP(id=0,umax_value=808464432,var_off=(0x0; 0x30303030)) R10=fp0
  4: (14) w6 -= 810299440
  5: R0_w=invP(id=0) R6_w=invP(id=0,umax_value=4294967295,var_off=(0xcf800000; 0x3077fff0)) R10=fp0
  5: (c4) w6 s>>= 1
  6: R0_w=invP(id=0) R6_w=invP(id=0,umin_value=3888119808,umax_value=4294705144,var_off=(0xe7c00000; 0x183bfff8)) R10=fp0
                                              (0x67c00000)          (0xfffbfff8)
  6: (76) if w6 s>= 0x30303030 goto pc+216
  7: R0_w=invP(id=0) R6_w=invP(id=0,umin_value=3888119808,umax_value=4294705144,var_off=(0xe7c00000; 0x183bfff8)) R10=fp0
  7: (30) r0 = *(u8 *)skb[808464432]
  BPF_LD_[ABS|IND] uses reserved fields
  processed 8 insns (limit 1000000) [...]

Fixes: 9cbe1f5a32 ("bpf/verifier: improve register value range tracking with ARSH")
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115204733.16648-1-daniel@iogearbox.net
2020-01-15 13:39:59 -08:00
Chunyan Zhang
5167c506d6 tick/common: Touch watchdog in tick_unfreeze() on all CPUs
Suspend to IDLE invokes tick_unfreeze() on resume. tick_unfreeze() on the
first resuming CPU resumes timekeeping, which also has the side effect of
resetting the softlockup watchdog on this CPU.

But on the secondary CPUs the watchdog is not reset in the resume /
unfreeze() path, which can result in false softlockup warnings on those
CPUs depending on the time spent in suspend.

Prevent this by clearing the softlock watchdog in the unfreeze path also
on the secondary resuming CPUs.

[ tglx: Massaged changelog ]

Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20200110083902.27276-1-chunyan.zhang@unisoc.com
2020-01-15 21:29:45 +01:00
Yonghong Song
8482941f09 bpf: Add bpf_send_signal_thread() helper
Commit 8b401f9ed2 ("bpf: implement bpf_send_signal() helper")
added helper bpf_send_signal() which permits bpf program to
send a signal to the current process. The signal may be
delivered to any threads in the process.

We found a use case where sending the signal to the current
thread is more preferable.
  - A bpf program will collect the stack trace and then
    send signal to the user application.
  - The user application will add some thread specific
    information to the just collected stack trace for
    later analysis.

If bpf_send_signal() is used, user application will need
to check whether the thread receiving the signal matches
the thread collecting the stack by checking thread id.
If not, it will need to send signal to another thread
through pthread_kill().

This patch proposed a new helper bpf_send_signal_thread(),
which sends the signal to the thread corresponding to
the current kernel task. This way, user space is guaranteed that
bpf_program execution context and user space signal handling
context are the same thread.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200115035002.602336-1-yhs@fb.com
2020-01-15 11:44:51 -08:00
Michal Koutný
3bc0bb36fa cgroup: Prevent double killing of css when enabling threaded cgroup
The test_cgcore_no_internal_process_constraint_on_threads selftest when
running with subsystem controlling noise triggers two warnings:

> [  597.443115] WARNING: CPU: 1 PID: 28167 at kernel/cgroup/cgroup.c:3131 cgroup_apply_control_enable+0xe0/0x3f0
> [  597.443413] WARNING: CPU: 1 PID: 28167 at kernel/cgroup/cgroup.c:3177 cgroup_apply_control_disable+0xa6/0x160

Both stem from a call to cgroup_type_write. The first warning was also
triggered by syzkaller.

When we're switching cgroup to threaded mode shortly after a subsystem
was disabled on it, we can see the respective subsystem css dying there.

The warning in cgroup_apply_control_enable is harmless in this case
since we're not adding new subsys anyway.
The warning in cgroup_apply_control_disable indicates an attempt to kill
css of recently disabled subsystem repeatedly.

The commit prevents these situations by making cgroup_type_write wait
for all dying csses to go away before re-applying subtree controls.
When at it, the locations of WARN_ON_ONCE calls are moved so that
warning is triggered only when we are about to misuse the dying css.

Reported-by: syzbot+5493b2a54d31d6aea629@syzkaller.appspotmail.com
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-01-15 08:04:29 -08:00
Daniel Jordan
1c5da0ec7f workqueue: add worker function to workqueue_execute_end tracepoint
It's surprising that workqueue_execute_end includes only the work when
its counterpart workqueue_execute_start has both the work and the worker
function.

You can't set a tracing filter or trigger based on the function, and
postprocessing scripts interested in specific functions are harder to
write since they have to remember the work from _start and match it up
with the same field in _end.

Add the function name, taking care to use the copy stashed in the
worker since the work is no longer safe to touch.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-01-15 08:02:47 -08:00
Chen Zhou
75ea91cd3e cgroup: fix function name in comment
Function name cgroup_rstat_cpu_pop_upated() in comment should be
cgroup_rstat_cpu_pop_updated().

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2020-01-15 07:58:13 -08:00
Jessica Yu
e9f35f634e modsign: print module name along with error message
It is useful to know which module failed signature verification, so
print the module name along with the error message.

Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-01-15 15:49:31 +01:00
Stephen Boyd
6b6d188aae alarmtimer: Unregister wakeup source when module get fails
The alarmtimer_rtc_add_device() function creates a wakeup source and then
tries to grab a module reference. If that fails the function returns early
with an error code, but fails to remove the wakeup source.

Cleanup this exit path so there is no dangling wakeup source, which is
named 'alarmtime' left allocated which will conflict with another RTC
device that may be registered later.

Fixes: 51218298a2 ("alarmtimer: Ensure RTC module is not unloaded")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200109155910.907-2-swboyd@chromium.org
2020-01-15 11:16:54 +01:00
Eric Dumazet
de95a991bb tick/sched: Annotate lockless access to last_jiffies_update
syzbot (KCSAN) reported a data-race in tick_do_update_jiffies64():

BUG: KCSAN: data-race in tick_do_update_jiffies64 / tick_do_update_jiffies64

write to 0xffffffff8603d008 of 8 bytes by interrupt on cpu 1:
 tick_do_update_jiffies64+0x100/0x250 kernel/time/tick-sched.c:73
 tick_sched_do_timer+0xd4/0xe0 kernel/time/tick-sched.c:138
 tick_sched_timer+0x43/0xe0 kernel/time/tick-sched.c:1292
 __run_hrtimer kernel/time/hrtimer.c:1514 [inline]
 __hrtimer_run_queues+0x274/0x5f0 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x22a/0x480 kernel/time/hrtimer.c:1638
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0xdc/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 arch_local_irq_restore arch/x86/include/asm/paravirt.h:756 [inline]
 kcsan_setup_watchpoint+0x1d4/0x460 kernel/kcsan/core.c:436
 check_access kernel/kcsan/core.c:466 [inline]
 __tsan_read1 kernel/kcsan/core.c:593 [inline]
 __tsan_read1+0xc2/0x100 kernel/kcsan/core.c:593
 kallsyms_expand_symbol.constprop.0+0x70/0x160 kernel/kallsyms.c:79
 kallsyms_lookup_name+0x7f/0x120 kernel/kallsyms.c:170
 insert_report_filterlist kernel/kcsan/debugfs.c:155 [inline]
 debugfs_write+0x14b/0x2d0 kernel/kcsan/debugfs.c:256
 full_proxy_write+0xbd/0x100 fs/debugfs/file.c:225
 __vfs_write+0x67/0xc0 fs/read_write.c:494
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x18a/0x390 fs/read_write.c:542
 ksys_write+0xd5/0x1b0 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x4c/0x60 fs/read_write.c:620
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffffff8603d008 of 8 bytes by task 0 on cpu 0:
 tick_do_update_jiffies64+0x2b/0x250 kernel/time/tick-sched.c:62
 tick_nohz_update_jiffies kernel/time/tick-sched.c:505 [inline]
 tick_nohz_irq_enter kernel/time/tick-sched.c:1257 [inline]
 tick_irq_enter+0x139/0x1c0 kernel/time/tick-sched.c:1274
 irq_enter+0x4f/0x60 kernel/softirq.c:354
 entering_irq arch/x86/include/asm/apic.h:517 [inline]
 entering_ack_irq arch/x86/include/asm/apic.h:523 [inline]
 smp_apic_timer_interrupt+0x55/0x280 arch/x86/kernel/apic/apic.c:1133
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60
 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571
 default_idle_call+0x1e/0x40 kernel/sched/idle.c:94
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x1af/0x280 kernel/sched/idle.c:263
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:355
 rest_init+0xec/0xf6 init/main.c:452
 arch_call_rest_init+0x17/0x37
 start_kernel+0x838/0x85e init/main.c:786
 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490
 x86_64_start_kernel+0x72/0x76 arch/x86/kernel/head64.c:471
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Use READ_ONCE() and WRITE_ONCE() to annotate this expected race.

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191205045619.204946-1-edumazet@google.com
2020-01-15 10:54:12 +01:00
Masami Hiramatsu
aeed8aa387 tracing: trigger: Replace unneeded RCU-list traversals
With CONFIG_PROVE_RCU_LIST, I had many suspicious RCU warnings
when I ran ftracetest trigger testcases.

-----
  # dmesg -c > /dev/null
  # ./ftracetest test.d/trigger
  ...
  # dmesg | grep "RCU-list traversed" | cut -f 2 -d ] | cut -f 2 -d " "
  kernel/trace/trace_events_hist.c:6070
  kernel/trace/trace_events_hist.c:1760
  kernel/trace/trace_events_hist.c:5911
  kernel/trace/trace_events_trigger.c:504
  kernel/trace/trace_events_hist.c:1810
  kernel/trace/trace_events_hist.c:3158
  kernel/trace/trace_events_hist.c:3105
  kernel/trace/trace_events_hist.c:5518
  kernel/trace/trace_events_hist.c:5998
  kernel/trace/trace_events_hist.c:6019
  kernel/trace/trace_events_hist.c:6044
  kernel/trace/trace_events_trigger.c:1500
  kernel/trace/trace_events_trigger.c:1540
  kernel/trace/trace_events_trigger.c:539
  kernel/trace/trace_events_trigger.c:584
-----

I investigated those warnings and found that the RCU-list
traversals in event trigger and hist didn't need to use
RCU version because those were called only under event_mutex.

I also checked other RCU-list traversals related to event
trigger list, and found that most of them were called from
event_hist_trigger_func() or hist_unregister_trigger() or
register/unregister functions except for a few cases.

Replace these unneeded RCU-list traversals with normal list
traversal macro and lockdep_assert_held() to check the
event_mutex is held.

Link: http://lkml.kernel.org/r/157680910305.11685.15110237954275915782.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: 30350d65ac ("tracing: Add variable support to hist triggers")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-14 17:12:04 -05:00
Steven Rostedt (VMware)
cfc585a401 ring-buffer: Fix kernel doc for rb_update_event()
rb_update_event has changed without the kernel-doc update.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-14 16:27:51 -05:00
Fabian Frederick
59e7cffe5c ring-bufer: kernel-doc warning fixes
Also fixes a couple of typos

Link: http://lkml.kernel.org/r/1401992525-10417-1-git-send-email-fabf@skynet.be

Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
[ Found this deep in the abyss of my INBOX ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-14 16:23:34 -05:00
Masami Hiramatsu
99c9a923e9 tracing/uprobe: Fix double perf_event linking on multiprobe uprobe
Fix double perf_event linking to trace_uprobe_filter on
multiple uprobe event by moving trace_uprobe_filter under
trace_probe_event.

In uprobe perf event, trace_uprobe_filter data structure is
managing target mm filters (in perf_event) related to each
uprobe event.

Since commit 60d53e2c3b ("tracing/probe: Split trace_event
related data from trace_probe") left the trace_uprobe_filter
data structure in trace_uprobe, if a trace_probe_event has
multiple trace_uprobe (multi-probe event), a perf_event is
added to different trace_uprobe_filter on each trace_uprobe.
This leads a linked list corruption.

To fix this issue, move trace_uprobe_filter to trace_probe_event
and link it once on each event instead of each probe.

Link: http://lkml.kernel.org/r/157862073931.1800.3800576241181489174.stgit@devnote2

Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S . Miller" <davem@davemloft.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: =?utf-8?q?Toke_H=C3=B8iland-J?= =?utf-8?b?w7hyZ2Vuc2Vu?= <thoiland@redhat.com>
Cc: Jean-Tsung Hsiao <jhsiao@redhat.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 60d53e2c3b ("tracing/probe: Split trace_event related data from trace_probe")
Link: https://lkml.kernel.org/r/20200108171611.GA8472@kernel.org
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-14 15:57:59 -05:00
Linus Torvalds
e033e7d4a8 Merge branch 'dhowells' (patches from DavidH)
Merge misc fixes from David Howells.

Two afs fixes and a key refcounting fix.

* dhowells:
  afs: Fix afs_lookup() to not clobber the version on a new dentry
  afs: Fix use-after-loss-of-ref
  keys: Fix request_key() cache
2020-01-14 09:56:31 -08:00
Martin KaFai Lau
3b4130418f bpf: Fix seq_show for BPF_MAP_TYPE_STRUCT_OPS
Instead of using bpf_struct_ops_map_lookup_elem() which is
not implemented, bpf_struct_ops_map_seq_show_elem() should
also use bpf_struct_ops_map_sys_lookup_elem() which does
an inplace update to the value.  The change allocates
a value to pass to bpf_struct_ops_map_sys_lookup_elem().

[root@arch-fb-vm1 bpf]# cat /sys/fs/bpf/dctcp
{{{1}},BPF_STRUCT_OPS_STATE_INUSE,{{00000000df93eebc,00000000df93eebc},0,2, ...

Fixes: 85d33df357 ("bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200114072647.3188298-1-kafai@fb.com
2020-01-14 09:54:31 -08:00
David Howells
8379bb84be keys: Fix request_key() cache
When the key cached by request_key() and co.  is cleaned up on exit(),
the code looks in the wrong task_struct, and so clears the wrong cache.
This leads to anomalies in key refcounting when doing, say, a kernel
build on an afs volume, that then trigger kasan to report a
use-after-free when the key is viewed in /proc/keys.

Fix this by making exit_creds() look in the passed-in task_struct rather
than in current (the task_struct cleanup code is deferred by RCU and
potentially run in another task).

Fixes: 7743c48e54 ("keys: Cache result of request_key*() temporarily in task_struct")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-14 09:40:06 -08:00
Jason Gunthorpe
984cfe4e25 mm/mmu_notifier: Rename struct mmu_notifier_mm to mmu_notifier_subscriptions
The name mmu_notifier_mm implies that the thing is a mm_struct pointer,
and is difficult to abbreviate. The struct is actually holding the
interval tree and hlist containing the notifiers subscribed to a mm.

Use 'subscriptions' as the variable name for this struct instead of the
really terrible and misleading 'mmn_mm'.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-01-14 11:54:47 -04:00
Andrei Vagin
04a8682a71 fs/proc: Introduce /proc/pid/timens_offsets
API to set time namespace offsets for children processes, i.e.:
echo "$clockid $offset_sec $offset_nsec" > /proc/self/timens_offsets

Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-28-dima@arista.com
2020-01-14 12:20:59 +01:00
Dmitry Safonov
70ddf65184 x86/vdso: Zap vvar pages when switching to a time namespace
The VVAR page layout depends on whether a task belongs to the root or
non-root time namespace. Whenever a task changes its namespace, the VVAR
page tables are cleared and then they will be re-faulted with a
corresponding layout.

Co-developed-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-27-dima@arista.com
2020-01-14 12:20:59 +01:00
Dmitry Safonov
afaa7b5ac7 time: Allocate per-timens vvar page
VDSO support for Time namespace needs to set up a page with the same
layout as VVAR. That timens page will be placed on position of VVAR page
inside namespace. That page contains time namespace clock offsets and it
has vdso_data->seq set to 1 to enforce the slow path and
vdso_data->clock_mode set to VCLOCK_TIMENS to enforce the time namespace
handling path.

Allocate the timens page during namespace creation. Setup the offsets
when the first task enters the ns and freeze them to guarantee the pace
of monotonic/boottime clocks and to avoid breakage of applications.

The design decision is to have a global offset_lock which is used during
namespace offsets setup and to freeze offsets when the first task joins the
new time namespace. That is better in terms of memory usage compared to
having a per namespace mutex that's used only during the setup period.

Suggested-by: Andy Lutomirski <luto@kernel.org>
Based-on-work-by: Thomas Gleixner <tglx@linutronix.de>
Co-developed-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-24-dima@arista.com
2020-01-14 12:20:58 +01:00
Andrei Vagin
1f9b37bfbb posix-timers: Make clock_nanosleep() time namespace aware
clock_nanosleep() accepts absolute values of expiration time, if the
TIMER_ABSTIME flag is set. This value is in the tasks time namespace,
which has to be converted to the host time namespace.

Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-18-dima@arista.com
2020-01-14 12:20:55 +01:00
Andrei Vagin
ea2d1f7fce hrtimers: Prepare hrtimer_nanosleep() for time namespaces
clock_nanosleep() accepts absolute values of expiration time when
TIMER_ABSTIME flag is set. This absolute value is inside the task's
time namespace, and has to be converted to the host's time.

There is timens_ktime_to_host() helper for converting time, but
it accepts ktime argument.

As a preparation, make hrtimer_nanosleep() accept a clock value in ktime
instead of timespec64.

Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-17-dima@arista.com
2020-01-14 12:20:55 +01:00
Andrei Vagin
0b9b9a3b16 alarmtimer: Make nanosleep() time namespace aware
clock_nanosleep() accepts absolute values of expiration time when the
TIMER_ABSTIME flag is set. This absolute value is inside the task's
time namespace and has to be converted to the host's time.

Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-16-dima@arista.com
2020-01-14 12:20:55 +01:00
Andrei Vagin
7da8b3a44b posix-timers: Make timer_settime() time namespace aware
Wire timer_settime() syscall into time namespace virtualization.

sys_timer_settime() calls the ktime->timer_set() callback. Right now,
common_timer_set() is the only implementation for the callback.

The user-supplied expiry value is converted from timespec64 to ktime and
then timens_ktime_to_host() can be used to convert namespace's time to the
host time.

Inside a time namespace kernel's time differs by a fixed offset from a
user-supplied time, but only absolute values (TIMER_ABSTIME) must be
converted.

Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-15-dima@arista.com
2020-01-14 12:20:54 +01:00
Andrei Vagin
89dd8eecfe time: Add do_timens_ktime_to_host() helper
The helper subtracts namespace's clock offset from the given time
and ensures that the result is within [0, KTIME_MAX].

Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-13-dima@arista.com
2020-01-14 12:20:53 +01:00
Andrei Vagin
5a590f35ad posix-clocks: Wire up clock_gettime() with timens offsets
Adjust monotonic and boottime clocks with per-timens offsets.  As the
result a process inside time namespace will see timers and clocks corrected
to offsets that were set when the namespace was created

Note that applications usually go through vDSO to get time, which is not
yet adjusted. Further changes will complete time namespace virtualisation
with vDSO support.

Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-12-dima@arista.com
2020-01-14 12:20:52 +01:00
Andrei Vagin
198fa445d5 posix-timers: Use clock_get_ktime() in common_timer_get()
Now, when the clock_get_ktime() callback exists, the suboptimal
timespec64-based conversion can be removed from common_timer_get().

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-11-dima@arista.com
2020-01-14 12:20:52 +01:00
Andrei Vagin
9c71a2e8a7 posix-clocks: Introduce clock_get_ktime() callback
The callsite in common_timer_get() has already a comment:
    /*
     * The timespec64 based conversion is suboptimal, but it's not
     * worth to implement yet another callback.
     */
    kc->clock_get(timr->it_clock, &ts64);
    now = timespec64_to_ktime(ts64);

The upcoming support for time namespaces requires to have access to:

 - The time in a task's time namespace for sys_clock_gettime()
 - The time in the root name space for common_timer_get()

That adds a valid reason to finally implement a separate callback which
returns the time in ktime_t format.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-10-dima@arista.com
2020-01-14 12:20:51 +01:00
Andrei Vagin
2f58bf909a alarmtimer: Provide get_timespec() callback
The upcoming support for time namespaces requires to have access to:

  - The time in a task's time namespace for sys_clock_gettime()
  - The time in the root name space for common_timer_get()

Wire up alarm bases with get_timespec().

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-9-dima@arista.com
2020-01-14 12:20:51 +01:00
Andrei Vagin
41b3b8dffc alarmtimer: Rename gettime() callback to get_ktime()
The upcoming support for time namespaces requires to have access to:

  - The time in a tasks time namespace for sys_clock_gettime()
  - The time in the root name space for common_timer_get()

struct alarm_base needs to follow the same naming convention, so rename
.gettime() callback into get_ktime() as a preparation for introducing
get_timespec().

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-8-dima@arista.com
2020-01-14 12:20:50 +01:00
Andrei Vagin
eaf80194d0 posix-clocks: Rename .clock_get_timespec() callbacks accordingly
The upcoming support for time namespaces requires to have access to:

  - The time in a task's time namespace for sys_clock_gettime()
  - The time in the root name space for common_timer_get()

That adds a valid reason to finally implement a separate callback which
returns the time in ktime_t format in (struct k_clock).

As a preparation ground for introducing clock_get_ktime(), the original
callback clock_get() was renamed into clock_get_timespec().
Reflect the renaming into the callback implementations.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-7-dima@arista.com
2020-01-14 12:20:50 +01:00
Andrei Vagin
819a95fe3a posix-clocks: Rename the clock_get() callback to clock_get_timespec()
The upcoming support for time namespaces requires to have access to:

 - The time in a task's time namespace for sys_clock_gettime()
 - The time in the root name space for common_timer_get()

That adds a valid reason to finally implement a separate callback which
returns the time in ktime_t format, rather than in (struct timespec).

Rename the clock_get() callback to clock_get_timespec() as a preparation
for introducing clock_get_ktime().

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-6-dima@arista.com
2020-01-14 12:20:49 +01:00
Andrei Vagin
af993f58d6 time: Add timens_offsets to be used for tasks in time namespace
Introduce offsets for time namespace. They will contain an adjustment
needed to convert clocks to/from host's.

A new namespace is created with the same offsets as the time namespace
of the current process.

Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-5-dima@arista.com
2020-01-14 12:20:49 +01:00
Andrei Vagin
769071ac9f ns: Introduce Time Namespace
Time Namespace isolates clock values.

The kernel provides access to several clocks CLOCK_REALTIME,
CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc.

CLOCK_REALTIME
      System-wide clock that measures real (i.e., wall-clock) time.

CLOCK_MONOTONIC
      Clock that cannot be set and represents monotonic time since
      some unspecified starting point.

CLOCK_BOOTTIME
      Identical to CLOCK_MONOTONIC, except it also includes any time
      that the system is suspended.

For many users, the time namespace means the ability to changes date and
time in a container (CLOCK_REALTIME). Providing per namespace notions of
CLOCK_REALTIME would be complex with a massive overhead, but has a dubious
value.

But in the context of checkpoint/restore functionality, monotonic and
boottime clocks become interesting. Both clocks are monotonic with
unspecified starting points. These clocks are widely used to measure time
slices and set timers. After restoring or migrating processes, it has to be
guaranteed that they never go backward. In an ideal case, the behavior of
these clocks should be the same as for a case when a whole system is
suspended. All this means that it is required to set CLOCK_MONOTONIC and
CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace
offsets for clocks.

A time namespace is similar to a pid namespace in the way how it is
created: unshare(CLONE_NEWTIME) system call creates a new time namespace,
but doesn't set it to the current process. Then all children of the process
will be born in the new time namespace, or a process can use the setns()
system call to join a namespace.

This scheme allows setting clock offsets for a namespace, before any
processes appear in it.

All available clone flags have been used, so CLONE_NEWTIME uses the highest
bit of CSIGNAL. It means that it can be used only with the unshare() and
the clone3() system calls.

[ tglx: Adjusted paragraph about clone3() to reality and massaged the
  	changelog a bit. ]

Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://criu.org/Time_namespace
Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html
Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2020-01-14 12:20:48 +01:00
Masami Hiramatsu
3b42a4c83a tracing: trigger: Replace unneeded RCU-list traversals
With CONFIG_PROVE_RCU_LIST, I had many suspicious RCU warnings
when I ran ftracetest trigger testcases.

-----
  # dmesg -c > /dev/null
  # ./ftracetest test.d/trigger
  ...
  # dmesg | grep "RCU-list traversed" | cut -f 2 -d ] | cut -f 2 -d " "
  kernel/trace/trace_events_hist.c:6070
  kernel/trace/trace_events_hist.c:1760
  kernel/trace/trace_events_hist.c:5911
  kernel/trace/trace_events_trigger.c:504
  kernel/trace/trace_events_hist.c:1810
  kernel/trace/trace_events_hist.c:3158
  kernel/trace/trace_events_hist.c:3105
  kernel/trace/trace_events_hist.c:5518
  kernel/trace/trace_events_hist.c:5998
  kernel/trace/trace_events_hist.c:6019
  kernel/trace/trace_events_hist.c:6044
  kernel/trace/trace_events_trigger.c:1500
  kernel/trace/trace_events_trigger.c:1540
  kernel/trace/trace_events_trigger.c:539
  kernel/trace/trace_events_trigger.c:584
-----

I investigated those warnings and found that the RCU-list
traversals in event trigger and hist didn't need to use
RCU version because those were called only under event_mutex.

I also checked other RCU-list traversals related to event
trigger list, and found that most of them were called from
event_hist_trigger_func() or hist_unregister_trigger() or
register/unregister functions except for a few cases.

Replace these unneeded RCU-list traversals with normal list
traversal macro and lockdep_assert_held() to check the
event_mutex is held.

Link: http://lkml.kernel.org/r/157680910305.11685.15110237954275915782.stgit@devnote2

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 15:59:11 -05:00
Sargun Dhillon
8649c322f7
pid: Implement pidfd_getfd syscall
This syscall allows for the retrieval of file descriptors from other
processes, based on their pidfd. This is possible using ptrace, and
injection of parasitic code to inject code which leverages SCM_RIGHTS
to move file descriptors between a tracee and a tracer. Unfortunately,
ptrace comes with a high cost of requiring the process to be stopped,
and breaks debuggers. This does not require stopping the process under
manipulation.

One reason to use this is to allow sandboxers to take actions on file
descriptors on the behalf of another process. For example, this can be
combined with seccomp-bpf's user notification to do on-demand fd
extraction and take privileged actions. One such privileged action
is binding a socket to a privileged port.

/* prototype */
  /* flags is currently reserved and should be set to 0 */
  int sys_pidfd_getfd(int pidfd, int fd, unsigned int flags);

/* testing */
Ran self-test suite on x86_64

Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200107175927.4558-3-sargun@sargun.me
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-01-13 21:49:36 +01:00
Masami Hiramatsu
fe1efe9252 tracing/boot: Add function tracer filter options
Add below function-tracer filter options to boot-time tracing.

 - ftrace.[instance.INSTANCE.]ftrace.filters
   This will take an array of tracing function filter rules

 - ftrace.[instance.INSTANCE.]ftrace.notraces
   This will take an array of NON-tracing function filter rules

Link: http://lkml.kernel.org/r/157867244841.17873.10933616628243103561.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:42 -05:00
Masami Hiramatsu
9d15dbbde1 tracing/boot: Add cpu_mask option support
Add ftrace.cpumask option support to boot-time tracing.
This sets cpumask for each instance.

 - ftrace.[instance.INSTANCE.]cpumask = CPUMASK;
   Set the trace cpumask. Note that the CPUMASK should be a string
   which <tracefs>/tracing_cpumask can accepts.

Link: http://lkml.kernel.org/r/157867243625.17873.13613922641273149372.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:42 -05:00
Masami Hiramatsu
4f712a4d04 tracing/boot: Add instance node support
Add instance node support to boot-time tracing. User can set
some options and event nodes under instance node.

 - ftrace.instance.INSTANCE[...]
   Add new INSTANCE instance. Some options and event nodes
   are acceptable for instance node.

Link: http://lkml.kernel.org/r/157867242413.17873.9814204526141500278.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:42 -05:00
Masami Hiramatsu
3fbe2d6e1f tracing/boot: Add synthetic event support
Add synthetic event node support to boot time tracing.
The synthetic event is a kind of event node, but the group
name is "synthetic".

 - ftrace.event.synthetic.EVENT.fields = FIELD[, FIELD2...]
   Defines new synthetic event with FIELDs. Each field should be
   "type varname".

The synthetic node requires "fields" string arraies, which defines
the fields as same as tracing/synth_events interface.

Link: http://lkml.kernel.org/r/157867241236.17873.12411615143321557709.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:42 -05:00
Masami Hiramatsu
4d655281eb tracing/boot Add kprobe event support
Add kprobe event support on event node to boot-time tracing.
If the group name of event is "kprobes", the boot-time tracing
defines new probe event according to "probes" values.

 - ftrace.event.kprobes.EVENT.probes = PROBE[, PROBE2...]
   Defines new kprobe event based on PROBEs. It is able to define
   multiple probes on one event, but those must have same type of
   arguments.

For example,

 ftrace.events.kprobes.myevent {
	probes = "vfs_read $arg1 $arg2";
	enable;
 }

This will add kprobes:myevent on vfs_read with the 1st and the 2nd
arguments.

Link: http://lkml.kernel.org/r/157867240104.17873.9712052065426433111.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:42 -05:00
Masami Hiramatsu
81a59555ff tracing/boot: Add per-event settings
Add per-event settings for boottime tracing. User can set filter,
actions and enable on each event on boot. The event entries are
under ftrace.event.GROUP.EVENT node (note that the option key
includes event's group name and event name.) This supports below
configs.

 - ftrace.event.GROUP.EVENT.enable
   Enables GROUP:EVENT tracing.

 - ftrace.event.GROUP.EVENT.filter = FILTER
   Set FILTER rule to the GROUP:EVENT.

 - ftrace.event.GROUP.EVENT.actions = ACTION[, ACTION2...]
   Set ACTIONs to the GROUP:EVENT.

For example,

  ftrace.event.sched.sched_process_exec {
                filter = "pid < 128"
		enable
  }

this will enable tracing "sched:sched_process_exec" event
with "pid < 128" filter.

Link: http://lkml.kernel.org/r/157867238942.17873.11177628789184546198.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:41 -05:00
Masami Hiramatsu
9c5b9d3d65 tracing/boot: Add boot-time tracing
Setup tracing options via extra boot config in addition to kernel
command line.

This adds following commands support. These are applied to
the global trace instance.

 - ftrace.options = OPT1[,OPT2...]
   Enable given ftrace options.

 - ftrace.trace_clock = CLOCK
   Set given CLOCK to ftrace's trace_clock.

 - ftrace.buffer_size = SIZE
   Configure ftrace buffer size to SIZE. You can use "KB" or "MB"
   for that SIZE.

 - ftrace.events = EVENT[, EVENT2...]
   Enable given events on boot. You can use a wild card in EVENT.

 - ftrace.tracer = TRACER
   Set TRACER to current tracer on boot. (e.g. function)

Note that this is NOT replacing the kernel parameters, because
this boot config based setting is later than that. If you want to
trace earlier boot events, you still need kernel parameters.

Link: http://lkml.kernel.org/r/157867237723.17873.17494943526320587488.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:41 -05:00
Masami Hiramatsu
48ac9488a5 tracing: Add NULL trace-array check in print_synth_event()
Add NULL trace-array check in print_synth_event(), because
if we enable tp_printk option, iter->tr can be NULL.

Link: http://lkml.kernel.org/r/157867236536.17873.12529350542460184019.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:41 -05:00
Masami Hiramatsu
b05e89ae7c tracing: Accept different type for synthetic event fields
Make the synthetic event accepts a different type field to record.
However, the size and signed flag must be same.

Link: http://lkml.kernel.org/r/157867235358.17873.61732996461602171.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:41 -05:00
Masami Hiramatsu
d8d4c6d0e7 tracing: kprobes: Register to dynevent earlier stage
Register kprobe event to dynevent in subsys_initcall level.
This will allow kernel to register new kprobe events in
fs_initcall level via trace_run_command.

Link: http://lkml.kernel.org/r/157867234213.17873.18039000024374948737.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:41 -05:00
Masami Hiramatsu
8cfcf15503 tracing: kprobes: Output kprobe event to printk buffer
Since kprobe-events use event_trigger_unlock_commit_regs() directly,
that events doesn't show up in printk buffer if "tp_printk" is set.

Use trace_event_buffer_commit() in kprobe events so that it can
invoke output_printk() as same as other trace events.

Link: http://lkml.kernel.org/r/157867233085.17873.5210928676787339604.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
[ Adjusted data var declaration placement in __kretprobe_trace_func() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:40 -05:00
Masami Hiramatsu
d8d0c245a7 tracing: Apply soft-disabled and filter to tracepoints printk
Apply soft-disabled and the filter rule of the trace events to
the printk output of tracepoints (a.k.a. tp_printk kernel parameter)
as same as trace buffer output.

Link: http://lkml.kernel.org/r/157867231876.17873.15825819592284704068.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:40 -05:00
Steven Rostedt (VMware)
1329249437 tracing: Make struct ring_buffer less ambiguous
As there's two struct ring_buffers in the kernel, it causes some confusion.
The other one being the perf ring buffer. It was agreed upon that as neither
of the ring buffers are generic enough to be used globally, they should be
renamed as:

   perf's ring_buffer -> perf_buffer
   ftrace's ring_buffer -> trace_buffer

This implements the changes to the ring buffer that ftrace uses.

Link: https://lore.kernel.org/r/20191213140531.116b3200@gandalf.local.home

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:38 -05:00
Steven Rostedt (VMware)
1c5eb4481e tracing: Rename trace_buffer to array_buffer
As we are working to remove the generic "ring_buffer" name that is used by
both tracing and perf, the ring_buffer name for tracing will be renamed to
trace_buffer, and perf's ring buffer will be renamed to perf_buffer.

As there already exists a trace_buffer that is used by the trace_arrays, it
needs to be first renamed to array_buffer.

Link: https://lore.kernel.org/r/20191213153553.GE20583@krava

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:38 -05:00
Steven Rostedt (VMware)
56de4e8f91 perf: Make struct ring_buffer less ambiguous
eBPF requires needing to know the size of the perf ring buffer structure.
But it unfortunately has the same name as the generic ring buffer used by
tracing and oprofile. To make it less ambiguous, rename the perf ring buffer
structure to "perf_buffer".

As other parts of the ring buffer code has "perf_" as the prefix, it only
makes sense to give the ring buffer the "perf_" prefix as well.

Link: https://lore.kernel.org/r/20191213153553.GE20583@krava
Acked-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:38 -05:00
Linus Torvalds
606e9ad200 clone3-tls-v5.5-rc6
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Merge tag 'clone3-tls-v5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull thread fixes from Christian Brauner:
 "This contains a series of patches to fix CLONE_SETTLS when used with
  clone3().

  The clone3() syscall passes the tls argument through struct clone_args
  instead of a register. This means, all architectures that do not
  implement copy_thread_tls() but still support CLONE_SETTLS via
  copy_thread() expecting the tls to be located in a register argument
  based on clone() are currently unfortunately broken. Their tls value
  will be garbage.

  The patch series fixes this on all architectures that currently define
  __ARCH_WANT_SYS_CLONE3. It also adds a compile-time check to ensure
  that any architecture that enables clone3() in the future is forced to
  also implement copy_thread_tls().

  My ultimate goal is to get rid of the copy_thread()/copy_thread_tls()
  split and just have copy_thread_tls() at some point in the not too
  distant future (Maybe even renaming copy_thread_tls() back to simply
  copy_thread() once the old function is ripped from all arches). This
  is dependent now on all arches supporting clone3().

  While all relevant arches do that now there are still four missing:
  ia64, m68k, sh and sparc. They have the system call reserved, but not
  implemented. Once they all implement clone3() we can get rid of
  ARCH_WANT_SYS_CLONE3 and HAVE_COPY_THREAD_TLS.

  This series also includes a minor fix for the arm64 uapi headers which
  caused __NR_clone3 to be missing from the exported user headers.

  Unfortunately the series came in a little late especially given that
  it touches a range of architectures. Due to the holidays not all arch
  maintainers responded in time probably due to their backlog. Will and
  Arnd have thankfully acked the arm specific changes.

  Given that the changes are straightforward and rather minimal combined
  with the fact the that clone3() with CLONE_SETTLS is broken I decided
  to send them post rc3 nonetheless"

* tag 'clone3-tls-v5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  um: Implement copy_thread_tls
  clone3: ensure copy_thread_tls is implemented
  xtensa: Implement copy_thread_tls
  riscv: Implement copy_thread_tls
  parisc: Implement copy_thread_tls
  arm: Implement copy_thread_tls
  arm64: Implement copy_thread_tls
  arm64: Move __ARCH_WANT_SYS_CLONE3 definition to uapi headers
2020-01-11 15:33:48 -08:00
Thomas Gleixner
2e34d63d82 Merge branch 'timers/urgent' into timers/core
Pick up upstream VDSO fix before adding more VDSO changes.
2020-01-10 21:11:54 +01:00
Alexei Starovoitov
51c39bb1d5 bpf: Introduce function-by-function verification
New llvm and old llvm with libbpf help produce BTF that distinguish global and
static functions. Unlike arguments of static function the arguments of global
functions cannot be removed or optimized away by llvm. The compiler has to use
exactly the arguments specified in a function prototype. The argument type
information allows the verifier validate each global function independently.
For now only supported argument types are pointer to context and scalars. In
the future pointers to structures, sizes, pointer to packet data can be
supported as well. Consider the following example:

static int f1(int ...)
{
  ...
}

int f3(int b);

int f2(int a)
{
  f1(a) + f3(a);
}

int f3(int b)
{
  ...
}

int main(...)
{
  f1(...) + f2(...) + f3(...);
}

The verifier will start its safety checks from the first global function f2().
It will recursively descend into f1() because it's static. Then it will check
that arguments match for the f3() invocation inside f2(). It will not descend
into f3(). It will finish f2() that has to be successfully verified for all
possible values of 'a'. Then it will proceed with f3(). That function also has
to be safe for all possible values of 'b'. Then it will start subprog 0 (which
is main() function). It will recursively descend into f1() and will skip full
check of f2() and f3(), since they are global. The order of processing global
functions doesn't affect safety, since all global functions must be proven safe
based on their arguments only.

Such function by function verification can drastically improve speed of the
verification and reduce complexity.

Note that the stack limit of 512 still applies to the call chain regardless whether
functions were static or global. The nested level of 8 also still applies. The
same recursion prevention checks are in place as well.

The type information and static/global kind is preserved after the verification
hence in the above example global function f2() and f3() can be replaced later
by equivalent functions with the same types that are loaded and verified later
without affecting safety of this main() program. Such replacement (re-linking)
of global functions is a subject of future patches.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200110064124.1760511-3-ast@kernel.org
2020-01-10 17:20:07 +01:00
Colin Ian King
5c0e9de065 PM: hibernate: fix spelling mistake "shapshot" -> "snapshot"
There is a spelling mistake in a pr_info message. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-01-10 12:15:30 +01:00
Alan Maguire
c475c77d5b kunit: allow kunit tests to be loaded as a module
As tests are added to kunit, it will become less feasible to execute
all built tests together.  By supporting modular tests we provide
a simple way to do selective execution on a running system; specifying

CONFIG_KUNIT=y
CONFIG_KUNIT_EXAMPLE_TEST=m

...means we can simply "insmod example-test.ko" to run the tests.

To achieve this we need to do the following:

o export the required symbols in kunit
o string-stream tests utilize non-exported symbols so for now we skip
  building them when CONFIG_KUNIT_TEST=m.
o drivers/base/power/qos-test.c contains a few unexported interface
  references, namely freq_qos_read_value() and freq_constraints_init().
  Both of these could be potentially defined as static inline functions
  in include/linux/pm_qos.h, but for now we simply avoid supporting
  module build for that test suite.
o support a new way of declaring test suites.  Because a module cannot
  do multiple late_initcall()s, we provide a kunit_test_suites() macro
  to declare multiple suites within the same module at once.
o some test module names would have been too general ("test-test"
  and "example-test" for kunit tests, "inode-test" for ext4 tests);
  rename these as appropriate ("kunit-test", "kunit-example-test"
  and "ext4-inode-test" respectively).

Also define kunit_test_suite() via kunit_test_suites()
as callers in other trees may need the old definition.

Co-developed-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Knut Omang <knut.omang@oracle.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Theodore Ts'o <tytso@mit.edu> # for ext4 bits
Acked-by: David Gow <davidgow@google.com> # For list-test
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-01-09 16:42:29 -07:00
David S. Miller
a2d6d7ae59 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The ungrafting from PRIO bug fixes in net, when merged into net-next,
merge cleanly but create a build failure.  The resolution used here is
from Petr Machata.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-09 12:13:43 -08:00
Linus Torvalds
a5f48c7878 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Missing netns pointer init in arp_tables, from Florian Westphal.

 2) Fix normal tcp SACK being treated as D-SACK, from Pengcheng Yang.

 3) Fix divide by zero in sch_cake, from Wen Yang.

 4) Len passed to skb_put_padto() is wrong in qrtr code, from Carl
    Huang.

 5) cmd->obj.chunk is leaked in sctp code error paths, from Xin Long.

 6) cgroup bpf programs can be released out of order, fix from Roman
    Gushchin.

 7) Make sure stmmac debugfs entry name is changed when device name
    changes, from Jiping Ma.

 8) Fix memory leak in vlan_dev_set_egress_priority(), from Eric
    Dumazet.

 9) SKB leak in lan78xx usb driver, also from Eric Dumazet.

10) Ridiculous TCA_FQ_QUANTUM values configured can cause loops in fq
    packet scheduler, reject them. From Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (69 commits)
  tipc: fix wrong connect() return code
  tipc: fix link overflow issue at socket shutdown
  netfilter: ipset: avoid null deref when IPSET_ATTR_LINENO is present
  netfilter: conntrack: dccp, sctp: handle null timeout argument
  atm: eni: fix uninitialized variable warning
  macvlan: do not assume mac_header is set in macvlan_broadcast()
  net: sch_prio: When ungrafting, replace with FIFO
  mlxsw: spectrum_qdisc: Ignore grafting of invisible FIFO
  MAINTAINERS: Remove myself as co-maintainer for qcom-ethqos
  gtp: fix bad unlock balance in gtp_encap_enable_socket
  pkt_sched: fq: do not accept silly TCA_FQ_QUANTUM
  tipc: remove meaningless assignment in Makefile
  tipc: do not add socket.o to tipc-y twice
  net: stmmac: dwmac-sun8i: Allow all RGMII modes
  net: stmmac: dwmac-sunxi: Allow all RGMII modes
  net: usb: lan78xx: fix possible skb leak
  net: stmmac: Fixed link does not need MDIO Bus
  vlan: vlan_changelink() should propagate errors
  vlan: fix memory leak in vlan_dev_set_egress_priority
  stmmac: debugfs entry name is not be changed when udev rename device name.
  ...
2020-01-09 10:34:07 -08:00
Paul Cercueil
2707745533 time/sched_clock: Disable interrupts in sched_clock_register()
Instead of issueing a warning if sched_clock_register() is called from a
context where IRQs are enabled, the code now ensures that IRQs are indeed
disabled.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200107010630.954648-1-paul@crapouillou.net
2020-01-09 18:50:18 +01:00
Arnd Bergmann
f35deaff1b time/posix-stubs: Provide compat itimer supoprt for alpha
Using compat_sys_getitimer and compat_sys_setitimer on alpha
causes a link failure in the Alpha tinyconfig and other configurations
that turn off CONFIG_POSIX_TIMERS.

Use the same #ifdef check for the stub version as well.

Fixes: 4c22ea2b91 ("y2038: use compat_{get,set}_itimer on alpha")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20191207191043.656328-1-arnd@arndb.de
2020-01-09 18:20:23 +01:00
Jules Irenge
099368bb10 genirq: Add missing __must_hold() sparse annotation
Add __must_hold() annotation to address the following sparse warning:

  warning: context imbalance in irq_wait_for_poll - unexpected unlock

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191216144208.29852-2-jbi.octave@gmail.com
2020-01-09 18:03:37 +01:00
Jules Irenge
8b3b54799b genirq: Add missing __releases() sparse annotation
Add __releases() annotation to address the following sparse warning:

  warning: context imbalance in __irq_put_desc_unlock() - unexpected unlock

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191216144208.29852-1-jbi.octave@gmail.com
2020-01-09 18:03:24 +01:00
Martin KaFai Lau
0baf26b0fc bpf: tcp: Support tcp_congestion_ops in bpf
This patch makes "struct tcp_congestion_ops" to be the first user
of BPF STRUCT_OPS.  It allows implementing a tcp_congestion_ops
in bpf.

The BPF implemented tcp_congestion_ops can be used like
regular kernel tcp-cc through sysctl and setsockopt.  e.g.
[root@arch-fb-vm1 bpf]# sysctl -a | egrep congestion
net.ipv4.tcp_allowed_congestion_control = reno cubic bpf_cubic
net.ipv4.tcp_available_congestion_control = reno bic cubic bpf_cubic
net.ipv4.tcp_congestion_control = bpf_cubic

There has been attempt to move the TCP CC to the user space
(e.g. CCP in TCP).   The common arguments are faster turn around,
get away from long-tail kernel versions in production...etc,
which are legit points.

BPF has been the continuous effort to join both kernel and
userspace upsides together (e.g. XDP to gain the performance
advantage without bypassing the kernel).  The recent BPF
advancements (in particular BTF-aware verifier, BPF trampoline,
BPF CO-RE...) made implementing kernel struct ops (e.g. tcp cc)
possible in BPF.  It allows a faster turnaround for testing algorithm
in the production while leveraging the existing (and continue growing)
BPF feature/framework instead of building one specifically for
userspace TCP CC.

This patch allows write access to a few fields in tcp-sock
(in bpf_tcp_ca_btf_struct_access()).

The optional "get_info" is unsupported now.  It can be added
later.  One possible way is to output the info with a btf-id
to describe the content.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003508.3856115-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau
85d33df357 bpf: Introduce BPF_MAP_TYPE_STRUCT_OPS
The patch introduces BPF_MAP_TYPE_STRUCT_OPS.  The map value
is a kernel struct with its func ptr implemented in bpf prog.
This new map is the interface to register/unregister/introspect
a bpf implemented kernel struct.

The kernel struct is actually embedded inside another new struct
(or called the "value" struct in the code).  For example,
"struct tcp_congestion_ops" is embbeded in:
struct bpf_struct_ops_tcp_congestion_ops {
	refcount_t refcnt;
	enum bpf_struct_ops_state state;
	struct tcp_congestion_ops data;  /* <-- kernel subsystem struct here */
}
The map value is "struct bpf_struct_ops_tcp_congestion_ops".
The "bpftool map dump" will then be able to show the
state ("inuse"/"tobefree") and the number of subsystem's refcnt (e.g.
number of tcp_sock in the tcp_congestion_ops case).  This "value" struct
is created automatically by a macro.  Having a separate "value" struct
will also make extending "struct bpf_struct_ops_XYZ" easier (e.g. adding
"void (*init)(void)" to "struct bpf_struct_ops_XYZ" to do some
initialization works before registering the struct_ops to the kernel
subsystem).  The libbpf will take care of finding and populating the
"struct bpf_struct_ops_XYZ" from "struct XYZ".

Register a struct_ops to a kernel subsystem:
1. Load all needed BPF_PROG_TYPE_STRUCT_OPS prog(s)
2. Create a BPF_MAP_TYPE_STRUCT_OPS with attr->btf_vmlinux_value_type_id
   set to the btf id "struct bpf_struct_ops_tcp_congestion_ops" of the
   running kernel.
   Instead of reusing the attr->btf_value_type_id,
   btf_vmlinux_value_type_id s added such that attr->btf_fd can still be
   used as the "user" btf which could store other useful sysadmin/debug
   info that may be introduced in the furture,
   e.g. creation-date/compiler-details/map-creator...etc.
3. Create a "struct bpf_struct_ops_tcp_congestion_ops" object as described
   in the running kernel btf.  Populate the value of this object.
   The function ptr should be populated with the prog fds.
4. Call BPF_MAP_UPDATE with the object created in (3) as
   the map value.  The key is always "0".

During BPF_MAP_UPDATE, the code that saves the kernel-func-ptr's
args as an array of u64 is generated.  BPF_MAP_UPDATE also allows
the specific struct_ops to do some final checks in "st_ops->init_member()"
(e.g. ensure all mandatory func ptrs are implemented).
If everything looks good, it will register this kernel struct
to the kernel subsystem.  The map will not allow further update
from this point.

Unregister a struct_ops from the kernel subsystem:
BPF_MAP_DELETE with key "0".

Introspect a struct_ops:
BPF_MAP_LOOKUP_ELEM with key "0".  The map value returned will
have the prog _id_ populated as the func ptr.

The map value state (enum bpf_struct_ops_state) will transit from:
INIT (map created) =>
INUSE (map updated, i.e. reg) =>
TOBEFREE (map value deleted, i.e. unreg)

The kernel subsystem needs to call bpf_struct_ops_get() and
bpf_struct_ops_put() to manage the "refcnt" in the
"struct bpf_struct_ops_XYZ".  This patch uses a separate refcnt
for the purose of tracking the subsystem usage.  Another approach
is to reuse the map->refcnt and then "show" (i.e. during map_lookup)
the subsystem's usage by doing map->refcnt - map->usercnt to filter out
the map-fd/pinned-map usage.  However, that will also tie down the
future semantics of map->refcnt and map->usercnt.

The very first subsystem's refcnt (during reg()) holds one
count to map->refcnt.  When the very last subsystem's refcnt
is gone, it will also release the map->refcnt.  All bpf_prog will be
freed when the map->refcnt reaches 0 (i.e. during map_free()).

Here is how the bpftool map command will look like:
[root@arch-fb-vm1 bpf]# bpftool map show
6: struct_ops  name dctcp  flags 0x0
	key 4B  value 256B  max_entries 1  memlock 4096B
	btf_id 6
[root@arch-fb-vm1 bpf]# bpftool map dump id 6
[{
        "value": {
            "refcnt": {
                "refs": {
                    "counter": 1
                }
            },
            "state": 1,
            "data": {
                "list": {
                    "next": 0,
                    "prev": 0
                },
                "key": 0,
                "flags": 2,
                "init": 24,
                "release": 0,
                "ssthresh": 25,
                "cong_avoid": 30,
                "set_state": 27,
                "cwnd_event": 28,
                "in_ack_event": 26,
                "undo_cwnd": 29,
                "pkts_acked": 0,
                "min_tso_segs": 0,
                "sndbuf_expand": 0,
                "cong_control": 0,
                "get_info": 0,
                "name": [98,112,102,95,100,99,116,99,112,0,0,0,0,0,0,0
                ],
                "owner": 0
            }
        }
    }
]

Misc Notes:
* bpf_struct_ops_map_sys_lookup_elem() is added for syscall lookup.
  It does an inplace update on "*value" instead returning a pointer
  to syscall.c.  Otherwise, it needs a separate copy of "zero" value
  for the BPF_STRUCT_OPS_STATE_INIT to avoid races.

* The bpf_struct_ops_map_delete_elem() is also called without
  preempt_disable() from map_delete_elem().  It is because
  the "->unreg()" may requires sleepable context, e.g.
  the "tcp_unregister_congestion_control()".

* "const" is added to some of the existing "struct btf_func_model *"
  function arg to avoid a compiler warning caused by this patch.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003505.3855919-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau
27ae7997a6 bpf: Introduce BPF_PROG_TYPE_STRUCT_OPS
This patch allows the kernel's struct ops (i.e. func ptr) to be
implemented in BPF.  The first use case in this series is the
"struct tcp_congestion_ops" which will be introduced in a
latter patch.

This patch introduces a new prog type BPF_PROG_TYPE_STRUCT_OPS.
The BPF_PROG_TYPE_STRUCT_OPS prog is verified against a particular
func ptr of a kernel struct.  The attr->attach_btf_id is the btf id
of a kernel struct.  The attr->expected_attach_type is the member
"index" of that kernel struct.  The first member of a struct starts
with member index 0.  That will avoid ambiguity when a kernel struct
has multiple func ptrs with the same func signature.

For example, a BPF_PROG_TYPE_STRUCT_OPS prog is written
to implement the "init" func ptr of the "struct tcp_congestion_ops".
The attr->attach_btf_id is the btf id of the "struct tcp_congestion_ops"
of the _running_ kernel.  The attr->expected_attach_type is 3.

The ctx of BPF_PROG_TYPE_STRUCT_OPS is an array of u64 args saved
by arch_prepare_bpf_trampoline that will be done in the next
patch when introducing BPF_MAP_TYPE_STRUCT_OPS.

"struct bpf_struct_ops" is introduced as a common interface for the kernel
struct that supports BPF_PROG_TYPE_STRUCT_OPS prog.  The supporting kernel
struct will need to implement an instance of the "struct bpf_struct_ops".

The supporting kernel struct also needs to implement a bpf_verifier_ops.
During BPF_PROG_LOAD, bpf_struct_ops_find() will find the right
bpf_verifier_ops by searching the attr->attach_btf_id.

A new "btf_struct_access" is also added to the bpf_verifier_ops such
that the supporting kernel struct can optionally provide its own specific
check on accessing the func arg (e.g. provide limited write access).

After btf_vmlinux is parsed, the new bpf_struct_ops_init() is called
to initialize some values (e.g. the btf id of the supporting kernel
struct) and it can only be done once the btf_vmlinux is available.

The R0 checks at BPF_EXIT is excluded for the BPF_PROG_TYPE_STRUCT_OPS prog
if the return type of the prog->aux->attach_func_proto is "void".

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003503.3855825-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau
976aba002f bpf: Support bitfield read access in btf_struct_access
This patch allows bitfield access as a scalar.

It checks "off + size > t->size" to avoid accessing bitfield
end up accessing beyond the struct.  This check is done
outside of the loop since it is applicable to all access.

It also takes this chance to break early on the "off < moff" case.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003501.3855427-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau
218b3f65f9 bpf: Add enum support to btf_ctx_access()
It allows bpf prog (e.g. tracing) to attach
to a kernel function that takes enum argument.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003459.3855366-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau
275517ff45 bpf: Avoid storing modifier to info->btf_id
info->btf_id expects the btf_id of a struct, so it should
store the final result after skipping modifiers (if any).

It also takes this chanace to add a missing newline in one of the
bpf_log() messages.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003456.3855176-1-kafai@fb.com
2020-01-09 08:46:18 -08:00
Martin KaFai Lau
65726b5b7e bpf: Save PTR_TO_BTF_ID register state when spilling to stack
This patch makes the verifier save the PTR_TO_BTF_ID register state when
spilling to the stack.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200109003454.3854870-1-kafai@fb.com
2020-01-09 08:45:32 -08:00
Arnd Bergmann
dc8d37ed30 cpu/SMT: Fix x86 link error without CONFIG_SYSFS
When CONFIG_SYSFS is disabled, but CONFIG_HOTPLUG_SMT is enabled,
the kernel fails to link:

arch/x86/power/cpu.o: In function `hibernate_resume_nonboot_cpu_disable':
(.text+0x38d): undefined reference to `cpuhp_smt_enable'
arch/x86/power/hibernate.o: In function `arch_resume_nosmt':
hibernate.c:(.text+0x291): undefined reference to `cpuhp_smt_enable'
hibernate.c:(.text+0x29c): undefined reference to `cpuhp_smt_disable'

Move the exported functions out of the #ifdef section into its
own with the correct conditions.

The patch that caused this is marked for stable backports, so
this one may need to be backported as well.

Fixes: ec527c3180 ("x86/power: Fix 'nosmt' vs hibernation triple fault during resume")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191210195614.786555-1-arnd@arndb.de
2020-01-09 17:31:45 +01:00
Luca Ceresoli
025af39b87 genirq: Show irq name in non-oneshot error message
Requesting a threaded IRQ with handler=NULL and !ONESHOT fails, but the
error message does not include the IRQ line name, which makes it harder to
find the offending driver.

Print the IRQ line name to clarify where the error comes from. Use the same
format as the other pr_err() above in the same function.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191105140854.27893-1-luca@lucaceresoli.net
2020-01-09 15:42:54 +01:00
Randy Dunlap
51bfb1d11d futex: Fix kernel-doc notation warning
Fix a kernel-doc warning in kernel/futex.c by adding notation
for @ret.

../kernel/futex.c:1187: warning: Function parameter or member 'ret' not described in 'wait_for_owner_exiting'

Fixes: 3ef240eaff ("futex: Prevent exit livelock")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/223be78c-f3c8-52df-836d-c5fb8e7907e9@infradead.org
2020-01-09 13:23:40 +01:00
Masami Hiramatsu
e4add24778 kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logic
optimize_kprobe() and unoptimize_kprobe() cancels if a given kprobe
is on the optimizing_list or unoptimizing_list already. However, since
the following commit:

  f66c0447cc ("kprobes: Set unoptimized flag after unoptimizing code")

modified the update timing of the KPROBE_FLAG_OPTIMIZED, it doesn't
work as expected anymore.

The optimized_kprobe could be in the following states:

- [optimizing]: Before inserting jump instruction
  op.kp->flags has KPROBE_FLAG_OPTIMIZED and
  op->list is not empty.

- [optimized]: jump inserted
  op.kp->flags has KPROBE_FLAG_OPTIMIZED and
  op->list is empty.

- [unoptimizing]: Before removing jump instruction (including unused
  optprobe)
  op.kp->flags has KPROBE_FLAG_OPTIMIZED and
  op->list is not empty.

- [unoptimized]: jump removed
  op.kp->flags doesn't have KPROBE_FLAG_OPTIMIZED and
  op->list is empty.

Current code mis-expects [unoptimizing] state doesn't have
KPROBE_FLAG_OPTIMIZED, and that can cause incorrect results.

To fix this, introduce optprobe_queued_unopt() to distinguish [optimizing]
and [unoptimizing] states and fixes the logic in optimize_kprobe() and
unoptimize_kprobe().

[ mingo: Cleaned up the changelog and the code a bit. ]

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bristot@redhat.com
Fixes: f66c0447cc ("kprobes: Set unoptimized flag after unoptimizing code")
Link: https://lkml.kernel.org/r/157840814418.7181.13478003006386303481.stgit@devnote2
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-09 12:40:13 +01:00
Pavel Tatashin
de68e4daea kexec: add machine_kexec_post_load()
It is the same as machine_kexec_prepare(), but is called after segments are
loaded. This way, can do processing work with already loaded relocation
segments. One such example is arm64: it has to have segments loaded in
order to create a page table, but it cannot do it during kexec time,
because at that time allocations won't be possible anymore.

Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-08 16:32:55 +00:00
Pavel Tatashin
d42cc530b1 kexec: quiet down kexec reboot
Here is a regular kexec command sequence and output:
=====
$ kexec --reuse-cmdline -i --load Image
$ kexec -e
[  161.342002] kexec_core: Starting new kernel

Welcome to Buildroot
buildroot login:
=====

Even when "quiet" kernel parameter is specified, "kexec_core: Starting
new kernel" is printed.

This message has  KERN_EMERG level, but there is no emergency, it is a
normal kexec operation, so quiet it down to appropriate KERN_NOTICE.

Machines that have slow console baud rate benefit from less output.

Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-08 16:32:55 +00:00
YueHaibing
f6d061d617 kernel/module: Fix memleak in module_add_modinfo_attrs()
In module_add_modinfo_attrs() if sysfs_create_file() fails
on the first iteration of the loop (so i = 0), we forget to
free the modinfo_attrs.

Fixes: bc6f2a757d ("kernel/module: Fix mem leak in module_add_modinfo_attrs")
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2020-01-08 17:07:20 +01:00
Amanieu d'Antras
dd499f7a7e
clone3: ensure copy_thread_tls is implemented
copy_thread implementations handle CLONE_SETTLS by reading the TLS
value from the registers containing the syscall arguments for
clone. This doesn't work with clone3 since the TLS value is passed
in clone_args instead.

Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: <stable@vger.kernel.org> # 5.3.x
Link: https://lore.kernel.org/r/20200102172413.654385-8-amanieu@gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-01-07 13:31:27 +01:00
Luigi Semenzato
7a7b99bf80 PM: hibernate: Add more logging on hibernation failure
Hibernation fails when the kernel cannot allocate enough memory
to copy all pages of RAM in use.

Ensure that the failure reason is clearly logged, and clearly
attributable to the hibernation module.

Signed-off-by: Luigi Semenzato <semenzato@google.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-01-07 13:31:12 +01:00
Wen Yang
809ed78a83 PM: hibernate: improve arithmetic division in preallocate_highmem_fraction()
do_div() does a 64-by-32 division. Use div64_u64() instead of
do_div() if the divisor is u64, to avoid truncation to 32-bit.

This change also cleans up code a tad.

Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-01-07 12:42:56 +01:00
Linus Torvalds
ae6088216c Various tracing fixes:
- kbuild found missing define of MCOUNT_INSN_SIZE for various build configs
  - Initialize variable to zero as gcc thinks it is used undefined
     (it really isn't but the code is subtle enough that this doesn't hurt)
  - Convert from do_div() to div64_ull() to prevent potential divide by zero
  - Unregister a trace point on error path in sched_wakeup tracer
  - Use signed offset for archs that can have stext not be first
  - A simple indentation fix (whitespace error)
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Merge tag 'trace-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Various tracing fixes:

   - kbuild found missing define of MCOUNT_INSN_SIZE for various build
     configs

   - Initialize variable to zero as gcc thinks it is used undefined (it
     really isn't but the code is subtle enough that this doesn't hurt)

   - Convert from do_div() to div64_ull() to prevent potential divide by
     zero

   - Unregister a trace point on error path in sched_wakeup tracer

   - Use signed offset for archs that can have stext not be first

   - A simple indentation fix (whitespace error)"

* tag 'trace-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix indentation issue
  kernel/trace: Fix do not unregister tracepoints when register sched_migrate_task fail
  tracing: Change offset type to s32 in preempt/irq tracepoints
  ftrace: Avoid potential division by zero in function profiler
  tracing: Have stack tracer compile when MCOUNT_INSN_SIZE is not defined
  tracing: Define MCOUNT_INSN_SIZE when not defined without direct calls
  tracing: Initialize val to zero in parse_entry of inject code
2020-01-06 15:38:38 -08:00
Daniel Borkmann
6d4f151acf bpf: Fix passing modified ctx to ld/abs/ind instruction
Anatoly has been fuzzing with kBdysch harness and reported a KASAN
slab oob in one of the outcomes:

  [...]
  [   77.359642] BUG: KASAN: slab-out-of-bounds in bpf_skb_load_helper_8_no_cache+0x71/0x130
  [   77.360463] Read of size 4 at addr ffff8880679bac68 by task bpf/406
  [   77.361119]
  [   77.361289] CPU: 2 PID: 406 Comm: bpf Not tainted 5.5.0-rc2-xfstests-00157-g2187f215eba #1
  [   77.362134] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
  [   77.362984] Call Trace:
  [   77.363249]  dump_stack+0x97/0xe0
  [   77.363603]  print_address_description.constprop.0+0x1d/0x220
  [   77.364251]  ? bpf_skb_load_helper_8_no_cache+0x71/0x130
  [   77.365030]  ? bpf_skb_load_helper_8_no_cache+0x71/0x130
  [   77.365860]  __kasan_report.cold+0x37/0x7b
  [   77.366365]  ? bpf_skb_load_helper_8_no_cache+0x71/0x130
  [   77.366940]  kasan_report+0xe/0x20
  [   77.367295]  bpf_skb_load_helper_8_no_cache+0x71/0x130
  [   77.367821]  ? bpf_skb_load_helper_8+0xf0/0xf0
  [   77.368278]  ? mark_lock+0xa3/0x9b0
  [   77.368641]  ? kvm_sched_clock_read+0x14/0x30
  [   77.369096]  ? sched_clock+0x5/0x10
  [   77.369460]  ? sched_clock_cpu+0x18/0x110
  [   77.369876]  ? bpf_skb_load_helper_8+0xf0/0xf0
  [   77.370330]  ___bpf_prog_run+0x16c0/0x28f0
  [   77.370755]  __bpf_prog_run32+0x83/0xc0
  [   77.371153]  ? __bpf_prog_run64+0xc0/0xc0
  [   77.371568]  ? match_held_lock+0x1b/0x230
  [   77.371984]  ? rcu_read_lock_held+0xa1/0xb0
  [   77.372416]  ? rcu_is_watching+0x34/0x50
  [   77.372826]  sk_filter_trim_cap+0x17c/0x4d0
  [   77.373259]  ? sock_kzfree_s+0x40/0x40
  [   77.373648]  ? __get_filter+0x150/0x150
  [   77.374059]  ? skb_copy_datagram_from_iter+0x80/0x280
  [   77.374581]  ? do_raw_spin_unlock+0xa5/0x140
  [   77.375025]  unix_dgram_sendmsg+0x33a/0xa70
  [   77.375459]  ? do_raw_spin_lock+0x1d0/0x1d0
  [   77.375893]  ? unix_peer_get+0xa0/0xa0
  [   77.376287]  ? __fget_light+0xa4/0xf0
  [   77.376670]  __sys_sendto+0x265/0x280
  [   77.377056]  ? __ia32_sys_getpeername+0x50/0x50
  [   77.377523]  ? lock_downgrade+0x350/0x350
  [   77.377940]  ? __sys_setsockopt+0x2a6/0x2c0
  [   77.378374]  ? sock_read_iter+0x240/0x240
  [   77.378789]  ? __sys_socketpair+0x22a/0x300
  [   77.379221]  ? __ia32_sys_socket+0x50/0x50
  [   77.379649]  ? mark_held_locks+0x1d/0x90
  [   77.380059]  ? trace_hardirqs_on_thunk+0x1a/0x1c
  [   77.380536]  __x64_sys_sendto+0x74/0x90
  [   77.380938]  do_syscall_64+0x68/0x2a0
  [   77.381324]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [   77.381878] RIP: 0033:0x44c070
  [...]

After further debugging, turns out while in case of other helper functions
we disallow passing modified ctx, the special case of ld/abs/ind instruction
which has similar semantics (except r6 being the ctx argument) is missing
such check. Modified ctx is impossible here as bpf_skb_load_helper_8_no_cache()
and others are expecting skb fields in original position, hence, add
check_ctx_reg() to reject any modified ctx. Issue was first introduced back
in f1174f77b5 ("bpf/verifier: rework value tracking").

Fixes: f1174f77b5 ("bpf/verifier: rework value tracking")
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200106215157.3553-1-daniel@iogearbox.net
2020-01-06 14:19:47 -08:00
Roman Gushchin
e10360f815 bpf: cgroup: prevent out-of-order release of cgroup bpf
Before commit 4bfc0bb2c6 ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself")
cgroup bpf structures were released with
corresponding cgroup structures. It guaranteed the hierarchical order
of destruction: children were always first. It preserved attached
programs from being released before their propagated copies.

But with cgroup auto-detachment there are no such guarantees anymore:
cgroup bpf is released as soon as the cgroup is offline and there are
no live associated sockets. It means that an attached program can be
detached and released, while its propagated copy is still living
in the cgroup subtree. This will obviously lead to an use-after-free
bug.

To reproduce the issue the following script can be used:

  #!/bin/bash

  CGROOT=/sys/fs/cgroup

  mkdir -p ${CGROOT}/A ${CGROOT}/B ${CGROOT}/A/C
  sleep 1

  ./test_cgrp2_attach ${CGROOT}/A egress &
  A_PID=$!
  ./test_cgrp2_attach ${CGROOT}/B egress &
  B_PID=$!

  echo $$ > ${CGROOT}/A/C/cgroup.procs
  iperf -s &
  S_PID=$!
  iperf -c localhost -t 100 &
  C_PID=$!

  sleep 1

  echo $$ > ${CGROOT}/B/cgroup.procs
  echo ${S_PID} > ${CGROOT}/B/cgroup.procs
  echo ${C_PID} > ${CGROOT}/B/cgroup.procs

  sleep 1

  rmdir ${CGROOT}/A/C
  rmdir ${CGROOT}/A

  sleep 1

  kill -9 ${S_PID} ${C_PID} ${A_PID} ${B_PID}

On the unpatched kernel the following stacktrace can be obtained:

[   33.619799] BUG: unable to handle page fault for address: ffffbdb4801ab002
[   33.620677] #PF: supervisor read access in kernel mode
[   33.621293] #PF: error_code(0x0000) - not-present page
[   33.622754] Oops: 0000 [#1] SMP NOPTI
[   33.623202] CPU: 0 PID: 601 Comm: iperf Not tainted 5.5.0-rc2+ #23
[   33.625545] RIP: 0010:__cgroup_bpf_run_filter_skb+0x29f/0x3d0
[   33.635809] Call Trace:
[   33.636118]  ? __cgroup_bpf_run_filter_skb+0x2bf/0x3d0
[   33.636728]  ? __switch_to_asm+0x40/0x70
[   33.637196]  ip_finish_output+0x68/0xa0
[   33.637654]  ip_output+0x76/0xf0
[   33.638046]  ? __ip_finish_output+0x1c0/0x1c0
[   33.638576]  __ip_queue_xmit+0x157/0x410
[   33.639049]  __tcp_transmit_skb+0x535/0xaf0
[   33.639557]  tcp_write_xmit+0x378/0x1190
[   33.640049]  ? _copy_from_iter_full+0x8d/0x260
[   33.640592]  tcp_sendmsg_locked+0x2a2/0xdc0
[   33.641098]  ? sock_has_perm+0x10/0xa0
[   33.641574]  tcp_sendmsg+0x28/0x40
[   33.641985]  sock_sendmsg+0x57/0x60
[   33.642411]  sock_write_iter+0x97/0x100
[   33.642876]  new_sync_write+0x1b6/0x1d0
[   33.643339]  vfs_write+0xb6/0x1a0
[   33.643752]  ksys_write+0xa7/0xe0
[   33.644156]  do_syscall_64+0x5b/0x1b0
[   33.644605]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fix this by grabbing a reference to the bpf structure of each ancestor
on the initialization of the cgroup bpf structure, and dropping the
reference at the end of releasing the cgroup bpf structure.

This will restore the hierarchical order of cgroup bpf releasing,
without adding any operations on hot paths.

Thanks to Josef Bacik for the debugging and the initial analysis of
the problem.

Fixes: 4bfc0bb2c6 ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself")
Reported-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-01-06 14:00:30 -08:00
Shakeel Butt
84029fd04c memcg: account security cred as well to kmemcg
The cred_jar kmem_cache is already memcg accounted in the current kernel
but cred->security is not.  Account cred->security to kmemcg.

Recently we saw high root slab usage on our production and on further
inspection, we found a buggy application leaking processes.  Though that
buggy application was contained within its memcg but we observe much
more system memory overhead, couple of GiBs, during that period.  This
overhead can adversely impact the isolation on the system.

One source of high overhead we found was cred->security objects, which
have a lifetime of at least the life of the process which allocated
them.

Link: http://lkml.kernel.org/r/20191205223721.40034-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-04 13:55:09 -08:00
Colin Ian King
72879ee0c5 tracing: Fix indentation issue
There is a declaration that is indented one level too deeply, remove
the extraneous tab.

Link: http://lkml.kernel.org/r/20191221154825.33073-1-colin.king@canonical.com

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-03 15:20:46 -05:00
Linus Torvalds
d9c82fd8c8 for-linus-2020-01-03
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Merge tag 'for-linus-2020-01-03' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull thread fixes from Christian Brauner:
 "Here are two fixes:

   - Panic earlier when global init exits to generate useable coredumps.

     Currently, when global init and all threads in its thread-group
     have exited we panic via:

       do_exit()
       -> exit_notify()
          -> forget_original_parent()
             -> find_child_reaper()

     This makes it hard to extract a useable coredump for global init
     from a kernel crashdump because by the time we panic exit_mm() will
     have already released global init's mm. We now panic slightly
     earlier. This has been a problem in certain environments such as
     Android.

   - Fix a race in assigning and reading taskstats for thread-groups
     with more than one thread.

     This patch has been waiting for quite a while since people
     disagreed on what the correct fix was at first"

* tag 'for-linus-2020-01-03' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  exit: panic before exit_mm() on global init exit
  taskstats: fix data-race
2020-01-03 11:17:14 -08:00
Kaitao Cheng
50f9ad607e kernel/trace: Fix do not unregister tracepoints when register sched_migrate_task fail
In the function, if register_trace_sched_migrate_task() returns error,
sched_switch/sched_wakeup_new/sched_wakeup won't unregister. That is
why fail_deprobe_sched_switch was added.

Link: http://lkml.kernel.org/r/20191231133530.2794-1-pilgrimtao@gmail.com

Cc: stable@vger.kernel.org
Fixes: 478142c39c ("tracing: do not grab lock in wakeup latency function tracing")
Signed-off-by: Kaitao Cheng <pilgrimtao@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-03 11:43:03 -05:00