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>
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>
* 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()
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
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
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>
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>
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>
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
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
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>
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>
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>
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>
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>
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
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
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
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
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
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
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
- 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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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
- 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
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
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>
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
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
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
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>
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>
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>
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
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
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
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
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>
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>
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>
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
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>
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
...
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
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
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
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[]
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
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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()
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>
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
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
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>
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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/
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
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
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
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
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
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
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
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
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>
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>
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
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>
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
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>
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
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
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
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
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
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
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
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
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>
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>
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>
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>
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
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>
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>
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>
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
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
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>
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>
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
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
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
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
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
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
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
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
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
