Pull timer fix from Ingo Molnar:
"Fix a timer expiry bug that would cause spurious delay of timers"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timer: Read jiffies once when forwarding base clk
Pull more perf updates from Ingo Molnar:
"The only kernel change is comment typo fixes.
The rest is mostly tooling fixes, but also new vendor event additions
and updates, a bigger libperf/libtraceevent library and a header files
reorganization that came in a bit late"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (108 commits)
perf unwind: Fix libunwind build failure on i386 systems
perf parser: Remove needless include directives
perf build: Add detection of java-11-openjdk-devel package
perf jvmti: Include JVMTI support for s390
perf vendor events: Remove P8 HW events which are not supported
perf evlist: Fix access of freed id arrays
perf stat: Fix free memory access / memory leaks in metrics
perf tools: Replace needless mmap.h with what is needed, event.h
perf evsel: Move config terms to a separate header
perf evlist: Remove unused perf_evlist__fprintf() method
perf evsel: Introduce evsel_fprintf.h
perf evsel: Remove need for symbol_conf in evsel_fprintf.c
perf copyfile: Move copyfile routines to separate files
libperf: Add perf_evlist__poll() function
libperf: Add perf_evlist__add_pollfd() function
libperf: Add perf_evlist__alloc_pollfd() function
libperf: Add libperf_init() call to the tests
libperf: Merge libperf_set_print() into libperf_init()
libperf: Add libperf dependency for tests targets
libperf: Use sys/types.h to get ssize_t, not unistd.h
...
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Merge tag 'trace-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Srikar Dronamraju fixed a bug in the newmulti probe code"
* tag 'trace-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/probe: Fix same probe event argument matching
In preparation for cleaning up "cut here", move the "cut here" logic up
out of __warn() and into callers that pass non-NULL args. For anyone
looking closely, there are two callers that pass NULL args: one already
explicitly prints "cut here". The remaining case is covered by how a WARN
is built, which will be cleaned up in the next patch.
Link: http://lkml.kernel.org/r/20190819234111.9019-5-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Clean up WARN() "cut here" handling", v2.
Christophe Leroy noticed that the fix for missing "cut here" in the WARN()
case was adding explicit printk() calls instead of teaching the exception
handler to add it. This refactors the bug/warn infrastructure to pass
this information as a new BUGFLAG.
Longer details repeated from the last patch in the series:
bug: move WARN_ON() "cut here" into exception handler
The original cleanup of "cut here" missed the WARN_ON() case (that does
not have a printk message), which was fixed recently by adding an explicit
printk of "cut here". This had the downside of adding a printk() to every
WARN_ON() caller, which reduces the utility of using an instruction
exception to streamline the resulting code. By making this a new BUGFLAG,
all of these can be removed and "cut here" can be handled by the exception
handler.
This was very pronounced on PowerPC, but the effect can be seen on x86 as
well. The resulting text size of a defconfig build shows some small
savings from this patch:
text data bss dec hex filename
19691167 5134320 1646664 26472151 193eed7 vmlinux.before
19676362 5134260 1663048 26473670 193f4c6 vmlinux.after
This change also opens the door for creating something like BUG_MSG(),
where a custom printk() before issuing BUG(), without confusing the "cut
here" line.
This patch (of 7):
There's no reason to have specialized helpers for passing the warn taint
down to __warn(). Consolidate and refactor helper macros, removing
__WARN_printf() and warn_slowpath_fmt_taint().
Link: http://lkml.kernel.org/r/20190819234111.9019-2-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now kgdb/kdb hooks up to debug panics by registering for the panic
notifier. This works OK except that it means that kgdb/kdb gets called
_after_ the CPUs in the system are taken offline. That means that if
anything important was happening on those CPUs (like something that might
have contributed to the panic) you can't debug them.
Specifically I ran into a case where I got a panic because a task was
"blocked for more than 120 seconds" which was detected on CPU 2. I nicely
got shown stack traces in the kernel log for all CPUs including CPU 0,
which was running 'PID: 111 Comm: kworker/0:1H' and was in the middle of
__mmc_switch().
I then ended up at the kdb prompt where switched over to kgdb to try to
look at local variables of the process on CPU 0. I found that I couldn't.
Digging more, I found that I had no info on any tasks running on CPUs
other than CPU 2 and that asking kdb for help showed me "Error: no saved
data for this cpu". This was because all the CPUs were offline.
Let's move the entry of kdb/kgdb to a direct call from panic() and stop
using the generic notifier. Putting a direct call in allows us to order
things more properly and it also doesn't seem like we're breaking any
abstractions by calling into the debugger from the panic function.
Daniel said:
: This patch changes the way kdump and kgdb interact with each other.
: However it would seem rather odd to have both tools simultaneously armed
: and, even if they were, the user still has the option to use panic_timeout
: to force a kdump to happen. Thus I think the change of order is
: acceptable.
Link: http://lkml.kernel.org/r/20190703170354.217312-1-dianders@chromium.org
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
syzbot found that a thread can stall for minutes inside kexec_load() after
that thread was killed by SIGKILL [1]. It turned out that the reproducer
was trying to allocate 2408MB of memory using kimage_alloc_page() from
kimage_load_normal_segment(). Let's check for SIGKILL before doing memory
allocation.
[1] https://syzkaller.appspot.com/bug?id=a0e3436829698d5824231251fad9d8e998f94f5e
Link: http://lkml.kernel.org/r/993c9185-d324-2640-d061-bed2dd18b1f7@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+8ab2d0f39fb79fe6ca40@syzkaller.appspotmail.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a user process exits, the kernel cleans up the mm_struct of the user
process and during cleanup, check_mm() checks the page tables of the user
process for corruption (E.g: unexpected page flags set/cleared). For
corrupted page tables, the error message printed by check_mm() isn't very
clear as it prints the loop index instead of page table type (E.g:
Resident file mapping pages vs Resident shared memory pages). The loop
index in check_mm() is used to index rss_stat[] which represents
individual memory type stats. Hence, instead of printing index, print
memory type, thereby improving error message.
Without patch:
--------------
[ 204.836425] mm/pgtable-generic.c:29: bad p4d 0000000089eb4e92(800000025f941467)
[ 204.836544] BUG: Bad rss-counter state mm:00000000f75895ea idx:0 val:2
[ 204.836615] BUG: Bad rss-counter state mm:00000000f75895ea idx:1 val:5
[ 204.836685] BUG: non-zero pgtables_bytes on freeing mm: 20480
With patch:
-----------
[ 69.815453] mm/pgtable-generic.c:29: bad p4d 0000000084653642(800000025ca37467)
[ 69.815872] BUG: Bad rss-counter state mm:00000000014a6c03 type:MM_FILEPAGES val:2
[ 69.815962] BUG: Bad rss-counter state mm:00000000014a6c03 type:MM_ANONPAGES val:5
[ 69.816050] BUG: non-zero pgtables_bytes on freeing mm: 20480
Also, change print function (from printk(KERN_ALERT, ..) to pr_alert()) so
that it matches the other print statement.
Link: http://lkml.kernel.org/r/da75b5153f617f4c5739c08ee6ebeb3d19db0fbc.1565123758.git.sai.praneeth.prakhya@intel.com
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When building with W=1, gcc properly complains that there's no prototypes:
CC kernel/elfcore.o
kernel/elfcore.c:7:17: warning: no previous prototype for 'elf_core_extra_phdrs' [-Wmissing-prototypes]
7 | Elf_Half __weak elf_core_extra_phdrs(void)
| ^~~~~~~~~~~~~~~~~~~~
kernel/elfcore.c:12:12: warning: no previous prototype for 'elf_core_write_extra_phdrs' [-Wmissing-prototypes]
12 | int __weak elf_core_write_extra_phdrs(struct coredump_params *cprm, loff_t offset)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/elfcore.c:17:12: warning: no previous prototype for 'elf_core_write_extra_data' [-Wmissing-prototypes]
17 | int __weak elf_core_write_extra_data(struct coredump_params *cprm)
| ^~~~~~~~~~~~~~~~~~~~~~~~~
kernel/elfcore.c:22:15: warning: no previous prototype for 'elf_core_extra_data_size' [-Wmissing-prototypes]
22 | size_t __weak elf_core_extra_data_size(void)
| ^~~~~~~~~~~~~~~~~~~~~~~~
Provide the include file so gcc is happy, and we don't have potential code drift
Link: http://lkml.kernel.org/r/29875.1565224705@turing-police
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When kzalloc() failed, NULL was returned to the caller, which
tested the pointer with IS_ERR(), which didn't match, so the
pointer was used later, resulting in a NULL dereference.
Return ERR_PTR(-ENOMEM) instead of NULL.
Reported-by: syzbot+491c1b7565ba9069ecae@syzkaller.appspotmail.com
Fixes: 0402acd683 ("xsk: remove AF_XDP socket from map when the socket is released")
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The EAS wake-up path computes the system energy for several CPU
candidates: the CPU with maximum spare capacity in each performance
domain, and the prev_cpu. However, if prev_cpu also happens to be the
CPU with maximum spare capacity in its performance domain, the energy
calculation is still done twice, unnecessarily.
Add a condition to filter out this corner case before doing the energy
calculation.
Reported-by: Pavan Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Quentin Perret <qperret@qperret.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dietmar.eggemann@arm.com
Cc: juri.lelli@redhat.com
Cc: morten.rasmussen@arm.com
Cc: qais.yousef@arm.com
Cc: rjw@rjwysocki.net
Cc: tkjos@google.com
Cc: valentin.schneider@arm.com
Cc: vincent.guittot@linaro.org
Fixes: eb92692b25 ("sched/fair: Speed-up energy-aware wake-ups")
Link: https://lkml.kernel.org/r/20190920094115.GA11503@qperret.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
update_max_interval() is called in both CPUHP_AP_SCHED_STARTING's startup
and teardown callbacks, but it turns out it's also called at the end of
the startup callback of CPUHP_AP_ACTIVE (which is further down the
startup sequence).
There's no point in repeating this interval update in the startup sequence
since the CPU will remain online until it goes down the teardown path.
Remove the redundant call in sched_cpu_activate() (CPUHP_AP_ACTIVE).
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dietmar.eggemann@arm.com
Cc: juri.lelli@redhat.com
Cc: vincent.guittot@linaro.org
Link: https://lkml.kernel.org/r/20190923093017.11755-1-valentin.schneider@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
de53fd7aed ("sched/fair: Fix low cpu usage with high throttling by removing expiration of cpu-local slices")
introduced a few compilation warnings:
kernel/sched/fair.c: In function '__refill_cfs_bandwidth_runtime':
kernel/sched/fair.c:4365:6: warning: variable 'now' set but not used [-Wunused-but-set-variable]
kernel/sched/fair.c: In function 'start_cfs_bandwidth':
kernel/sched/fair.c:4992:6: warning: variable 'overrun' set but not used [-Wunused-but-set-variable]
Also, __refill_cfs_bandwidth_runtime() does no longer update the
expiration time, so fix the comments accordingly.
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ben Segall <bsegall@google.com>
Reviewed-by: Dave Chiluk <chiluk+linux@indeed.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: pauld@redhat.com
Fixes: de53fd7aed ("sched/fair: Fix low cpu usage with high throttling by removing expiration of cpu-local slices")
Link: https://lkml.kernel.org/r/1566326455-8038-1-git-send-email-cai@lca.pw
Signed-off-by: Ingo Molnar <mingo@kernel.org>
An oops can be triggered in the scheduler when running qemu on arm64:
Unable to handle kernel paging request at virtual address ffff000008effe40
Internal error: Oops: 96000007 [#1] SMP
Process migration/0 (pid: 12, stack limit = 0x00000000084e3736)
pstate: 20000085 (nzCv daIf -PAN -UAO)
pc : __ll_sc___cmpxchg_case_acq_4+0x4/0x20
lr : move_queued_task.isra.21+0x124/0x298
...
Call trace:
__ll_sc___cmpxchg_case_acq_4+0x4/0x20
__migrate_task+0xc8/0xe0
migration_cpu_stop+0x170/0x180
cpu_stopper_thread+0xec/0x178
smpboot_thread_fn+0x1ac/0x1e8
kthread+0x134/0x138
ret_from_fork+0x10/0x18
__set_cpus_allowed_ptr() will choose an active dest_cpu in affinity mask to
migrage the process if process is not currently running on any one of the
CPUs specified in affinity mask. __set_cpus_allowed_ptr() will choose an
invalid dest_cpu (dest_cpu >= nr_cpu_ids, 1024 in my virtual machine) if
CPUS in an affinity mask are deactived by cpu_down after cpumask_intersects
check. cpumask_test_cpu() of dest_cpu afterwards is overflown and may pass if
corresponding bit is coincidentally set. As a consequence, kernel will
access an invalid rq address associate with the invalid CPU in
migration_cpu_stop->__migrate_task->move_queued_task and the Oops occurs.
The reproduce the crash:
1) A process repeatedly binds itself to cpu0 and cpu1 in turn by calling
sched_setaffinity.
2) A shell script repeatedly does "echo 0 > /sys/devices/system/cpu/cpu1/online"
and "echo 1 > /sys/devices/system/cpu/cpu1/online" in turn.
3) Oops appears if the invalid CPU is set in memory after tested cpumask.
Signed-off-by: KeMeng Shi <shikemeng@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1568616808-16808-1-git-send-email-shikemeng@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Remove the IPI fallback code from membarrier to deal with very
infrequent cpumask memory allocation failure. Use GFP_KERNEL rather
than GFP_NOWAIT, and relax the blocking guarantees for the expedited
membarrier system call commands, allowing it to block if waiting for
memory to be made available.
In addition, now -ENOMEM can be returned to user-space if the cpumask
memory allocation fails.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-8-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If there is only a single mm_user for the mm, the private expedited
membarrier command can skip the IPIs, because only a single thread
is using the mm.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-7-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The membarrier_state field is located within the mm_struct, which
is not guaranteed to exist when used from runqueue-lock-free iteration
on runqueues by the membarrier system call.
Copy the membarrier_state from the mm_struct into the scheduler runqueue
when the scheduler switches between mm.
When registering membarrier for mm, after setting the registration bit
in the mm membarrier state, issue a synchronize_rcu() to ensure the
scheduler observes the change. In order to take care of the case
where a runqueue keeps executing the target mm without swapping to
other mm, iterate over each runqueue and issue an IPI to copy the
membarrier_state from the mm_struct into each runqueue which have the
same mm which state has just been modified.
Move the mm membarrier_state field closer to pgd in mm_struct to use
a cache line already touched by the scheduler switch_mm.
The membarrier_execve() (now membarrier_exec_mmap) hook now needs to
clear the runqueue's membarrier state in addition to clear the mm
membarrier state, so move its implementation into the scheduler
membarrier code so it can access the runqueue structure.
Add memory barrier in membarrier_exec_mmap() prior to clearing
the membarrier state, ensuring memory accesses executed prior to exec
are not reordered with the stores clearing the membarrier state.
As suggested by Linus, move all membarrier.c RCU read-side locks outside
of the for each cpu loops.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-5-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Checking that the number of threads is 1 is redundant with checking
mm_users == 1.
No change in functionality intended.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-3-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fix a logic flaw in the way membarrier_register_private_expedited()
handles ready state checks for private expedited sync core and private
expedited registrations.
If a private expedited membarrier registration is first performed, and
then a private expedited sync_core registration is performed, the ready
state check will skip the second registration when it really should not.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190919173705.2181-2-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The current task on the runqueue is currently read with rcu_dereference().
To obtain ordinary RCU semantics for an rcu_dereference() of rq->curr it needs
to be paired with rcu_assign_pointer() of rq->curr. Which provides the
memory barrier necessary to order assignments to the task_struct
and the assignment to rq->curr.
Unfortunately the assignment of rq->curr in __schedule is a hot path,
and it has already been show that additional barriers in that code
will reduce the performance of the scheduler. So I will attempt to
describe below why you can effectively have ordinary RCU semantics
without any additional barriers.
The assignment of rq->curr in init_idle is a slow path called once
per cpu and that can use rcu_assign_pointer() without any concerns.
As I write this there are effectively two users of rcu_dereference() on
rq->curr. There is the membarrier code in kernel/sched/membarrier.c
that only looks at "->mm" after the rcu_dereference(). Then there is
task_numa_compare() in kernel/sched/fair.c. My best reading of the
code shows that task_numa_compare only access: "->flags",
"->cpus_ptr", "->numa_group", "->numa_faults[]",
"->total_numa_faults", and "->se.cfs_rq".
The code in __schedule() essentially does:
rq_lock(...);
smp_mb__after_spinlock();
next = pick_next_task(...);
rq->curr = next;
context_switch(prev, next);
At the start of the function the rq_lock/smp_mb__after_spinlock
pair provides a full memory barrier. Further there is a full memory barrier
in context_switch().
This means that any task that has already run and modified itself (the
common case) has already seen two memory barriers before __schedule()
runs and begins executing. A task that modifies itself then sees a
third full memory barrier pair with the rq_lock();
For a brand new task that is enqueued with wake_up_new_task() there
are the memory barriers present from the taking and release the
pi_lock and the rq_lock as the processes is enqueued as well as the
full memory barrier at the start of __schedule() assuming __schedule()
happens on the same cpu.
This means that by the time we reach the assignment of rq->curr
except for values on the task struct modified in pick_next_task
the code has the same guarantees as if it used rcu_assign_pointer().
Reading through all of the implementations of pick_next_task it
appears pick_next_task is limited to modifying the task_struct fields
"->se", "->rt", "->dl". These fields are the sched_entity structures
of the varies schedulers.
Further "->se.cfs_rq" is only changed in cgroup attach/move operations
initialized by userspace.
Unless I have missed something this means that in practice that the
users of "rcu_dereference(rq->curr)" get normal RCU semantics of
rcu_dereference() for the fields the care about, despite the
assignment of rq->curr in __schedule() ot using rcu_assign_pointer.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20190903200603.GW2349@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Remove work arounds that were written before there was a grace period
after tasks left the runqueue in finish_task_switch().
In particular now that there tasks exiting the runqueue exprience
a RCU grace period none of the work performed by task_rcu_dereference()
excpet the rcu_dereference() is necessary so replace task_rcu_dereference()
with rcu_dereference().
Remove the code in rcuwait_wait_event() that checks to ensure the current
task has not exited. It is no longer necessary as it is guaranteed
that any running task will experience a RCU grace period after it
leaves the run queueue.
Remove the comment in rcuwait_wake_up() as it is no longer relevant.
Ref: 8f95c90ceb ("sched/wait, RCU: Introduce rcuwait machinery")
Ref: 150593bf86 ("sched/api: Introduce task_rcu_dereference() and try_get_task_struct()")
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87lfurdpk9.fsf_-_@x220.int.ebiederm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In the ordinary case today the RCU grace period for a task_struct is
triggered when another process wait's for it's zombine and causes the
kernel to call release_task(). As the waiting task has to receive a
signal and then act upon it before this happens, typically this will
occur after the original task as been removed from the runqueue.
Unfortunaty in some cases such as self reaping tasks it can be shown
that release_task() will be called starting the grace period for
task_struct long before the task leaves the runqueue.
Therefore use put_task_struct_rcu_user() in finish_task_switch() to
guarantee that the there is a RCU lifetime after the task
leaves the runqueue.
Besides the change in the start of the RCU grace period for the
task_struct this change may cause perf_event_delayed_put and
trace_sched_process_free. The function perf_event_delayed_put boils
down to just a WARN_ON for cases that I assume never show happen. So
I don't see any problem with delaying it.
The function trace_sched_process_free is a trace point and thus
visible to user space. Occassionally userspace has the strangest
dependencies so this has a miniscule chance of causing a regression.
This change only changes the timing of when the tracepoint is called.
The change in timing arguably gives userspace a more accurate picture
of what is going on. So I don't expect there to be a regression.
In the case where a task self reaps we are pretty much guaranteed that
the RCU grace period is delayed. So we should get quite a bit of
coverage in of this worst case for the change in a normal threaded
workload. So I expect any issues to turn up quickly or not at all.
I have lightly tested this change and everything appears to work
fine.
Inspired-by: Linus Torvalds <torvalds@linux-foundation.org>
Inspired-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87r24jdpl5.fsf_-_@x220.int.ebiederm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add a count of the number of RCU users (currently 1) of the task
struct so that we can later add the scheduler case and get rid of the
very subtle task_rcu_dereference(), and just use rcu_dereference().
As suggested by Oleg have the count overlap rcu_head so that no
additional space in task_struct is required.
Inspired-by: Linus Torvalds <torvalds@linux-foundation.org>
Inspired-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/87woebdplt.fsf_-_@x220.int.ebiederm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit fe60b0ce8e ("tracing/probe: Reject exactly same probe event")
tries to reject a event which matches an already existing probe.
However it currently continues to match arguments and rejects adding a
probe even when the arguments don't match. Fix this by only rejecting a
probe if and only if all the arguments match.
Link: http://lkml.kernel.org/r/20190924114906.14038-1-srikar@linux.vnet.ibm.com
Fixes: fe60b0ce8e ("tracing/probe: Reject exactly same probe event")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This patch reverts commit 75437bb304 (locking/pvqspinlock: Don't
wait if vCPU is preempted). A large performance regression was caused
by this commit. on over-subscription scenarios.
The test was run on a Xeon Skylake box, 2 sockets, 40 cores, 80 threads,
with three VMs of 80 vCPUs each. The score of ebizzy -M is reduced from
13000-14000 records/s to 1700-1800 records/s:
Host Guest score
vanilla w/o kvm optimizations upstream 1700-1800 records/s
vanilla w/o kvm optimizations revert 13000-14000 records/s
vanilla w/ kvm optimizations upstream 4500-5000 records/s
vanilla w/ kvm optimizations revert 14000-15500 records/s
Exit from aggressive wait-early mechanism can result in premature yield
and extra scheduling latency.
Actually, only 6% of wait_early events are caused by vcpu_is_preempted()
being true. However, when one vCPU voluntarily releases its vCPU, all
the subsequently waiters in the queue will do the same and the cascading
effect leads to bad performance.
kvm optimizations:
[1] commit d73eb57b80 (KVM: Boost vCPUs that are delivering interrupts)
[2] commit 266e85a5ec (KVM: X86: Boost queue head vCPU to mitigate lock waiter preemption)
Tested-by: loobinliu@tencent.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: loobinliu@tencent.com
Cc: stable@vger.kernel.org
Fixes: 75437bb304 (locking/pvqspinlock: Don't wait if vCPU is preempted)
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Merge updates from Andrew Morton:
- a few hot fixes
- ocfs2 updates
- almost all of -mm (slab-generic, slab, slub, kmemleak, kasan,
cleanups, debug, pagecache, memcg, gup, pagemap, memory-hotplug,
sparsemem, vmalloc, initialization, z3fold, compaction, mempolicy,
oom-kill, hugetlb, migration, thp, mmap, madvise, shmem, zswap,
zsmalloc)
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (132 commits)
mm/zsmalloc.c: fix a -Wunused-function warning
zswap: do not map same object twice
zswap: use movable memory if zpool support allocate movable memory
zpool: add malloc_support_movable to zpool_driver
shmem: fix obsolete comment in shmem_getpage_gfp()
mm/madvise: reduce code duplication in error handling paths
mm: mmap: increase sockets maximum memory size pgoff for 32bits
mm/mmap.c: refine find_vma_prev() with rb_last()
riscv: make mmap allocation top-down by default
mips: use generic mmap top-down layout and brk randomization
mips: replace arch specific way to determine 32bit task with generic version
mips: adjust brk randomization offset to fit generic version
mips: use STACK_TOP when computing mmap base address
mips: properly account for stack randomization and stack guard gap
arm: use generic mmap top-down layout and brk randomization
arm: use STACK_TOP when computing mmap base address
arm: properly account for stack randomization and stack guard gap
arm64, mm: make randomization selected by generic topdown mmap layout
arm64, mm: move generic mmap layout functions to mm
arm64: consider stack randomization for mmap base only when necessary
...
arm64 handles top-down mmap layout in a way that can be easily reused by
other architectures, so make it available in mm. It then introduces a new
config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT that can be set by other
architectures to benefit from those functions. Note that this new config
depends on MMU being enabled, if selected without MMU support, a warning
will be thrown.
Link: http://lkml.kernel.org/r/20190730055113.23635-5-alex@ghiti.fr
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: James Hogan <jhogan@kernel.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After all uprobes are removed from the huge page (with PTE pgtable), it is
possible to collapse the pmd and benefit from THP again. This patch does
the collapse by calling collapse_pte_mapped_thp().
Link: http://lkml.kernel.org/r/20190815164525.1848545-7-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: kbuild test robot <lkp@intel.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the newly added FOLL_SPLIT_PMD in uprobe. This preserves the huge
page when the uprobe is enabled. When the uprobe is disabled, newer
instances of the same application could still benefit from huge page.
For the next step, we will enable khugepaged to regroup the pmd, so that
existing instances of the application could also benefit from huge page
after the uprobe is disabled.
Link: http://lkml.kernel.org/r/20190815164525.1848545-5-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, uprobe swaps the target page with a anonymous page in both
install_breakpoint() and remove_breakpoint(). When all uprobes on a page
are removed, the given mm is still using an anonymous page (not the
original page).
This patch allows uprobe to use original page when possible (all uprobes
on the page are already removed, and the original page is in page cache
and uptodate).
As suggested by Oleg, we unmap the old_page and let the original page
fault in.
Link: http://lkml.kernel.org/r/20190815164525.1848545-3-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/memory_hotplug: online_pages() cleanups", v2.
Some cleanups (+ one fix for a special case) in the context of
online_pages().
This patch (of 5):
This makes it clearer that we will never call func() with duplicate PFNs
in case we have multiple sub-page memory resources. All unaligned parts
of PFNs are completely discarded.
Link: http://lkml.kernel.org/r/20190814154109.3448-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: remove quicklist page table caches".
A while ago Nicholas proposed to remove quicklist page table caches [1].
I've rebased his patch on the curren upstream and switched ia64 and sh to
use generic versions of PTE allocation.
[1] https://lore.kernel.org/linux-mm/20190711030339.20892-1-npiggin@gmail.com
This patch (of 3):
Remove page table allocator "quicklists". These have been around for a
long time, but have not got much traction in the last decade and are only
used on ia64 and sh architectures.
The numbers in the initial commit look interesting but probably don't
apply anymore. If anybody wants to resurrect this it's in the git
history, but it's unhelpful to have this code and divergent allocator
behaviour for minor archs.
Also it might be better to instead make more general improvements to page
allocator if this is still so slow.
Link: http://lkml.kernel.org/r/1565250728-21721-2-git-send-email-rppt@linux.ibm.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull more mount API conversions from Al Viro:
"Assorted conversions of options parsing to new API.
gfs2 is probably the most serious one here; the rest is trivial stuff.
Other things in what used to be #work.mount are going to wait for the
next cycle (and preferably go via git trees of the filesystems
involved)"
* 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
gfs2: Convert gfs2 to fs_context
vfs: Convert spufs to use the new mount API
vfs: Convert hypfs to use the new mount API
hypfs: Fix error number left in struct pointer member
vfs: Convert functionfs to use the new mount API
vfs: Convert bpf to use the new mount API
KVM needs to know if SMT is theoretically possible, this means it is
supported and not forcefully disabled ('nosmt=force'). Create and
export cpu_smt_possible() answering this question.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull livepatching fix from Jiri Kosina:
"Error handling fix in livepatching module notifier, from Miroslav
Benes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
livepatch: Nullify obj->mod in klp_module_coming()'s error path
Summary of modules changes for the 5.4 merge window:
- Introduce exported symbol namespaces.
This new feature allows subsystem maintainers to partition and
categorize their exported symbols into explicit namespaces. Module
authors are now required to import the namespaces they need.
Some of the main motivations of this feature include: allowing kernel
developers to better manage the export surface, allow subsystem
maintainers to explicitly state that usage of some exported symbols
should only be limited to certain users (think: inter-module or
inter-driver symbols, debugging symbols, etc), as well as more easily
limiting the availability of namespaced symbols to other parts of the
kernel. With the module import requirement, it is also easier to spot
the misuse of exported symbols during patch review. Two new macros are
introduced: EXPORT_SYMBOL_NS() and EXPORT_SYMBOL_NS_GPL(). The API is
thoroughly documented in Documentation/kbuild/namespaces.rst.
- Some small code and kbuild cleanups here and there.
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Merge tag 'modules-for-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull modules updates from Jessica Yu:
"The main bulk of this pull request introduces a new exported symbol
namespaces feature. The number of exported symbols is increasingly
growing with each release (we're at about 31k exports as of 5.3-rc7)
and we currently have no way of visualizing how these symbols are
"clustered" or making sense of this huge export surface.
Namespacing exported symbols allows kernel developers to more
explicitly partition and categorize exported symbols, as well as more
easily limiting the availability of namespaced symbols to other parts
of the kernel. For starters, we have introduced the USB_STORAGE
namespace to demonstrate the API's usage. I have briefly summarized
the feature and its main motivations in the tag below.
Summary:
- Introduce exported symbol namespaces.
This new feature allows subsystem maintainers to partition and
categorize their exported symbols into explicit namespaces. Module
authors are now required to import the namespaces they need.
Some of the main motivations of this feature include: allowing
kernel developers to better manage the export surface, allow
subsystem maintainers to explicitly state that usage of some
exported symbols should only be limited to certain users (think:
inter-module or inter-driver symbols, debugging symbols, etc), as
well as more easily limiting the availability of namespaced symbols
to other parts of the kernel.
With the module import requirement, it is also easier to spot the
misuse of exported symbols during patch review.
Two new macros are introduced: EXPORT_SYMBOL_NS() and
EXPORT_SYMBOL_NS_GPL(). The API is thoroughly documented in
Documentation/kbuild/namespaces.rst.
- Some small code and kbuild cleanups here and there"
* tag 'modules-for-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
module: Remove leftover '#undef' from export header
module: remove unneeded casts in cmp_name()
module: move CONFIG_UNUSED_SYMBOLS to the sub-menu of MODULES
module: remove redundant 'depends on MODULES'
module: Fix link failure due to invalid relocation on namespace offset
usb-storage: export symbols in USB_STORAGE namespace
usb-storage: remove single-use define for debugging
docs: Add documentation for Symbol Namespaces
scripts: Coccinelle script for namespace dependencies.
modpost: add support for generating namespace dependencies
export: allow definition default namespaces in Makefiles or sources
module: add config option MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
modpost: add support for symbol namespaces
module: add support for symbol namespaces.
export: explicitly align struct kernel_symbol
module: support reading multiple values per modinfo tag
- virtio support
- Fixes for our new time travel mode
- Various improvements to make lockdep and kasan work better
- SPDX header updates
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Merge tag 'for-linus-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Pull UML updates from Richard Weinberger:
- virtio support
- fixes for our new time travel mode
- various improvements to make lockdep and kasan work better
- SPDX header updates
* tag 'for-linus-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: (25 commits)
um: irq: Fix LAST_IRQ usage in init_IRQ()
um: Add SPDX headers for files in arch/um/include
um: Add SPDX headers for files in arch/um/os-Linux
um: Add SPDX headers to files in arch/um/kernel/
um: Add SPDX headers for files in arch/um/drivers
um: virtio: Implement VHOST_USER_PROTOCOL_F_REPLY_ACK
um: virtio: Implement VHOST_USER_PROTOCOL_F_SLAVE_REQ
um: drivers: Add virtio vhost-user driver
um: Use real DMA barriers
um: Don't use generic barrier.h
um: time-travel: Restrict time update in IRQ handler
um: time-travel: Fix periodic timers
um: Enable CONFIG_CONSTRUCTORS
um: Place (soft)irq text with macros
um: Fix VDSO compiler warning
um: Implement TRACE_IRQFLAGS_SUPPORT
um: Remove misleading #define ARCh_IRQ_ENABLED
um: Avoid using uninitialized regs
um: Remove sig_info[SIGALRM]
um: Error handling fixes in vector drivers
...
This is more cleanup and consolidation of the hmm APIs and the very
strongly related mmu_notifier interfaces. Many places across the tree
using these interfaces are touched in the process. Beyond that a cleanup
to the page walker API and a few memremap related changes round out the
series:
- General improvement of hmm_range_fault() and related APIs, more
documentation, bug fixes from testing, API simplification &
consolidation, and unused API removal
- Simplify the hmm related kconfigs to HMM_MIRROR and DEVICE_PRIVATE, and
make them internal kconfig selects
- Hoist a lot of code related to mmu notifier attachment out of drivers by
using a refcount get/put attachment idiom and remove the convoluted
mmu_notifier_unregister_no_release() and related APIs.
- General API improvement for the migrate_vma API and revision of its only
user in nouveau
- Annotate mmu_notifiers with lockdep and sleeping region debugging
Two series unrelated to HMM or mmu_notifiers came along due to
dependencies:
- Allow pagemap's memremap_pages family of APIs to work without providing
a struct device
- Make walk_page_range() and related use a constant structure for function
pointers
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull hmm updates from Jason Gunthorpe:
"This is more cleanup and consolidation of the hmm APIs and the very
strongly related mmu_notifier interfaces. Many places across the tree
using these interfaces are touched in the process. Beyond that a
cleanup to the page walker API and a few memremap related changes
round out the series:
- General improvement of hmm_range_fault() and related APIs, more
documentation, bug fixes from testing, API simplification &
consolidation, and unused API removal
- Simplify the hmm related kconfigs to HMM_MIRROR and DEVICE_PRIVATE,
and make them internal kconfig selects
- Hoist a lot of code related to mmu notifier attachment out of
drivers by using a refcount get/put attachment idiom and remove the
convoluted mmu_notifier_unregister_no_release() and related APIs.
- General API improvement for the migrate_vma API and revision of its
only user in nouveau
- Annotate mmu_notifiers with lockdep and sleeping region debugging
Two series unrelated to HMM or mmu_notifiers came along due to
dependencies:
- Allow pagemap's memremap_pages family of APIs to work without
providing a struct device
- Make walk_page_range() and related use a constant structure for
function pointers"
* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (75 commits)
libnvdimm: Enable unit test infrastructure compile checks
mm, notifier: Catch sleeping/blocking for !blockable
kernel.h: Add non_block_start/end()
drm/radeon: guard against calling an unpaired radeon_mn_unregister()
csky: add missing brackets in a macro for tlb.h
pagewalk: use lockdep_assert_held for locking validation
pagewalk: separate function pointers from iterator data
mm: split out a new pagewalk.h header from mm.h
mm/mmu_notifiers: annotate with might_sleep()
mm/mmu_notifiers: prime lockdep
mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end
mm/mmu_notifiers: remove the __mmu_notifier_invalidate_range_start/end exports
mm/hmm: hmm_range_fault() infinite loop
mm/hmm: hmm_range_fault() NULL pointer bug
mm/hmm: fix hmm_range_fault()'s handling of swapped out pages
mm/mmu_notifiers: remove unregister_no_release
RDMA/odp: remove ib_ucontext from ib_umem
RDMA/odp: use mmu_notifier_get/put for 'struct ib_ucontext_per_mm'
RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr
RDMA/mlx5: Use ib_umem_start instead of umem.address
...
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Merge tag 'printk-for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk updates from Petr Mladek:
- Fix off-by-one error when calculating messages that might fit into
kmsg buffer. It causes occasional omitting of the last message.
- Add missing pointer check in %pD format modifier handling.
- Some clean up
* tag 'printk-for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
ABI: Update dev-kmsg documentation to match current kernel behaviour
printk: Replace strncmp() with str_has_prefix()
lib/test_printf: Remove obvious comments from %pd and %pD tests
lib/test_printf: Add test of null/invalid pointer dereference for dentry
vsprintf: Prevent crash when dereferencing invalid pointers for %pD
printk: Do not lose last line in kmsg buffer dump
* Now that wq->rescuer may be cleared while rescuer is still there,
switch show_pwq() debug printout to test worker->rescue_wq to
identify rescuers intead of testing wq->rescuer.
* Update comment on ->rescuer locking.
Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Lai Jiangshan <jiangshanlai@gmail.com>
Fix typos in a few functions' documentation comments.
Signed-off-by: Roy Ben Shlomo <royb@sentinelone.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: royb@sentinelone.com
Link: http://lore.kernel.org/lkml/20190920171254.31373-1-royb@sentinelone.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
- Initial support for running on a system with an Ultravisor, which is software
that runs below the hypervisor and protects guests against some attacks by
the hypervisor.
- Support for building the kernel to run as a "Secure Virtual Machine", ie. as
a guest capable of running on a system with an Ultravisor.
- Some changes to our DMA code on bare metal, to allow devices with medium
sized DMA masks (> 32 && < 59 bits) to use more than 2GB of DMA space.
- Support for firmware assisted crash dumps on bare metal (powernv).
- Two series fixing bugs in and refactoring our PCI EEH code.
- A large series refactoring our exception entry code to use gas macros, both
to make it more readable and also enable some future optimisations.
As well as many cleanups and other minor features & fixups.
Thanks to:
Adam Zerella, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh
Kumar K.V, Anju T Sudhakar, Anshuman Khandual, Balbir Singh, Benjamin
Herrenschmidt, Cédric Le Goater, Christophe JAILLET, Christophe Leroy,
Christopher M. Riedl, Christoph Hellwig, Claudio Carvalho, Daniel Axtens,
David Gibson, David Hildenbrand, Desnes A. Nunes do Rosario, Ganesh Goudar,
Gautham R. Shenoy, Greg Kurz, Guerney Hunt, Gustavo Romero, Halil Pasic, Hari
Bathini, Joakim Tjernlund, Jonathan Neuschafer, Jordan Niethe, Leonardo Bras,
Lianbo Jiang, Madhavan Srinivasan, Mahesh Salgaonkar, Mahesh Salgaonkar,
Masahiro Yamada, Maxiwell S. Garcia, Michael Anderson, Nathan Chancellor,
Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Qian Cai, Ram
Pai, Ravi Bangoria, Reza Arbab, Ryan Grimm, Sam Bobroff, Santosh Sivaraj,
Segher Boessenkool, Sukadev Bhattiprolu, Thiago Bauermann, Thiago Jung
Bauermann, Thomas Gleixner, Tom Lendacky, Vasant Hegde.
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Merge tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"This is a bit late, partly due to me travelling, and partly due to a
power outage knocking out some of my test systems *while* I was
travelling.
- Initial support for running on a system with an Ultravisor, which
is software that runs below the hypervisor and protects guests
against some attacks by the hypervisor.
- Support for building the kernel to run as a "Secure Virtual
Machine", ie. as a guest capable of running on a system with an
Ultravisor.
- Some changes to our DMA code on bare metal, to allow devices with
medium sized DMA masks (> 32 && < 59 bits) to use more than 2GB of
DMA space.
- Support for firmware assisted crash dumps on bare metal (powernv).
- Two series fixing bugs in and refactoring our PCI EEH code.
- A large series refactoring our exception entry code to use gas
macros, both to make it more readable and also enable some future
optimisations.
As well as many cleanups and other minor features & fixups.
Thanks to: Adam Zerella, Alexey Kardashevskiy, Alistair Popple, Andrew
Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anshuman Khandual,
Balbir Singh, Benjamin Herrenschmidt, Cédric Le Goater, Christophe
JAILLET, Christophe Leroy, Christopher M. Riedl, Christoph Hellwig,
Claudio Carvalho, Daniel Axtens, David Gibson, David Hildenbrand,
Desnes A. Nunes do Rosario, Ganesh Goudar, Gautham R. Shenoy, Greg
Kurz, Guerney Hunt, Gustavo Romero, Halil Pasic, Hari Bathini, Joakim
Tjernlund, Jonathan Neuschafer, Jordan Niethe, Leonardo Bras, Lianbo
Jiang, Madhavan Srinivasan, Mahesh Salgaonkar, Mahesh Salgaonkar,
Masahiro Yamada, Maxiwell S. Garcia, Michael Anderson, Nathan
Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver
O'Halloran, Qian Cai, Ram Pai, Ravi Bangoria, Reza Arbab, Ryan Grimm,
Sam Bobroff, Santosh Sivaraj, Segher Boessenkool, Sukadev Bhattiprolu,
Thiago Bauermann, Thiago Jung Bauermann, Thomas Gleixner, Tom
Lendacky, Vasant Hegde"
* tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (264 commits)
powerpc/mm/mce: Keep irqs disabled during lockless page table walk
powerpc: Use ftrace_graph_ret_addr() when unwinding
powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
ftrace: Look up the address of return_to_handler() using helpers
powerpc: dump kernel log before carrying out fadump or kdump
docs: powerpc: Add missing documentation reference
powerpc/xmon: Fix output of XIVE IPI
powerpc/xmon: Improve output of XIVE interrupts
powerpc/mm/radix: remove useless kernel messages
powerpc/fadump: support holes in kernel boot memory area
powerpc/fadump: remove RMA_START and RMA_END macros
powerpc/fadump: update documentation about option to release opalcore
powerpc/fadump: consider f/w load area
powerpc/opalcore: provide an option to invalidate /sys/firmware/opal/core file
powerpc/opalcore: export /sys/firmware/opal/core for analysing opal crashes
powerpc/fadump: update documentation about CONFIG_PRESERVE_FA_DUMP
powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel
powerpc/fadump: improve how crashed kernel's memory is reserved
powerpc/fadump: consider reserved ranges while releasing memory
powerpc/fadump: make crash memory ranges array allocation generic
...
- Addition of multiprobes to kprobe and uprobe events
Allows for more than one probe attached to the same location
- Addition of adding immediates to probe parameters
- Clean up of the recordmcount.c code. This brings us closer
to merging recordmcount into objtool, and reuse code.
- Other small clean ups
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Merge tag 'trace-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
- Addition of multiprobes to kprobe and uprobe events (allows for more
than one probe attached to the same location)
- Addition of adding immediates to probe parameters
- Clean up of the recordmcount.c code. This brings us closer to merging
recordmcount into objtool, and reuse code.
- Other small clean ups
* tag 'trace-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
selftests/ftrace: Update kprobe event error testcase
tracing/probe: Reject exactly same probe event
tracing/probe: Fix to allow user to enable events on unloaded modules
selftests/ftrace: Select an existing function in kprobe_eventname test
tracing/kprobe: Fix NULL pointer access in trace_porbe_unlink()
tracing: Make sure variable reference alias has correct var_ref_idx
tracing: Be more clever when dumping hex in __print_hex()
ftrace: Simplify ftrace hash lookup code in clear_func_from_hash()
tracing: Add "gfp_t" support in synthetic_events
tracing: Rename tracing_reset() to tracing_reset_cpu()
tracing: Document the stack trace algorithm in the comments
tracing/arm64: Have max stack tracer handle the case of return address after data
recordmcount: Clarify what cleanup() does
recordmcount: Remove redundant cleanup() calls
recordmcount: Kernel style formatting
recordmcount: Kernel style function signature formatting
recordmcount: Rewrite error/success handling
selftests/ftrace: Add syntax error test for multiprobe
selftests/ftrace: Add syntax error test for immediates
selftests/ftrace: Add a testcase for kprobe multiprobe event
...
It has been a quiet dev cycle for kgdb. There has been some good stuff
for kdb on the mailing list but unfortunately the patches caused a
couple of problems with the kdb pager so I had to drop those and they
will have to wait for next time!
That just leaves us with just a couple of very tiny clean ups for now:
* Fix a broken comment
* Use str_has_prefix() for the grep "pipe" in kdb
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
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Merge tag 'kgdb-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux
Pull kgdb updates from Daniel Thompson:
"It has been a quiet dev cycle for kgdb. There has been some good stuff
for kdb on the mailing list but unfortunately the patches caused a
couple of problems with the kdb pager so I had to drop those and they
will have to wait for next time!
That just leaves us with just a couple of very tiny clean ups for now:
- Fix a broken comment
- Use str_has_prefix() for the grep "pipe" in kdb"
* tag 'kgdb-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
kgdb: fix comment regarding static function
kdb: Replace strncmp with str_has_prefix
- add modpost warn exported symbols marked as 'static' because 'static'
and EXPORT_SYMBOL is an odd combination
- break the build early if gold linker is used
- optimize the Bison rule to produce .c and .h files by a single
pattern rule
- handle PREEMPT_RT in the module vermagic and UTS_VERSION
- warn CONFIG options leaked to the user-space except existing ones
- make single targets work properly
- rebuild modules when module linker scripts are updated
- split the module final link stage into scripts/Makefile.modfinal
- fix the missed error code in merge_config.sh
- improve the error message displayed on the attempt of the O= build
in unclean source tree
- remove 'clean-dirs' syntax
- disable -Wimplicit-fallthrough warning for Clang
- add CONFIG_CC_OPTIMIZE_FOR_SIZE_O3 for ARC
- remove ARCH_{CPP,A,C}FLAGS variables
- add $(BASH) to run bash scripts
- change *CFLAGS_<basetarget>.o to take the relative path to $(obj)
instead of the basename
- stop suppressing Clang's -Wunused-function warnings when W=1
- fix linux/export.h to avoid genksyms calculating CRC of trimmed
exported symbols
- misc cleanups
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Merge tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- add modpost warn exported symbols marked as 'static' because 'static'
and EXPORT_SYMBOL is an odd combination
- break the build early if gold linker is used
- optimize the Bison rule to produce .c and .h files by a single
pattern rule
- handle PREEMPT_RT in the module vermagic and UTS_VERSION
- warn CONFIG options leaked to the user-space except existing ones
- make single targets work properly
- rebuild modules when module linker scripts are updated
- split the module final link stage into scripts/Makefile.modfinal
- fix the missed error code in merge_config.sh
- improve the error message displayed on the attempt of the O= build in
unclean source tree
- remove 'clean-dirs' syntax
- disable -Wimplicit-fallthrough warning for Clang
- add CONFIG_CC_OPTIMIZE_FOR_SIZE_O3 for ARC
- remove ARCH_{CPP,A,C}FLAGS variables
- add $(BASH) to run bash scripts
- change *CFLAGS_<basetarget>.o to take the relative path to $(obj)
instead of the basename
- stop suppressing Clang's -Wunused-function warnings when W=1
- fix linux/export.h to avoid genksyms calculating CRC of trimmed
exported symbols
- misc cleanups
* tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (63 commits)
genksyms: convert to SPDX License Identifier for lex.l and parse.y
modpost: use __section in the output to *.mod.c
modpost: use MODULE_INFO() for __module_depends
export.h, genksyms: do not make genksyms calculate CRC of trimmed symbols
export.h: remove defined(__KERNEL__), which is no longer needed
kbuild: allow Clang to find unused static inline functions for W=1 build
kbuild: rename KBUILD_ENABLE_EXTRA_GCC_CHECKS to KBUILD_EXTRA_WARN
kbuild: refactor scripts/Makefile.extrawarn
merge_config.sh: ignore unwanted grep errors
kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)
modpost: add NOFAIL to strndup
modpost: add guid_t type definition
kbuild: add $(BASH) to run scripts with bash-extension
kbuild: remove ARCH_{CPP,A,C}FLAGS
kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC
kbuild: Do not enable -Wimplicit-fallthrough for clang for now
kbuild: clean up subdir-ymn calculation in Makefile.clean
kbuild: remove unneeded '+' marker from cmd_clean
kbuild: remove clean-dirs syntax
kbuild: check clean srctree even earlier
...
- add dma-mapping and block layer helpers to take care of IOMMU
merging for mmc plus subsequent fixups (Yoshihiro Shimoda)
- rework handling of the pgprot bits for remapping (me)
- take care of the dma direct infrastructure for swiotlb-xen (me)
- improve the dma noncoherent remapping infrastructure (me)
- better defaults for ->mmap, ->get_sgtable and ->get_required_mask (me)
- cleanup mmaping of coherent DMA allocations (me)
- various misc cleanups (Andy Shevchenko, me)
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Merge tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig:
- add dma-mapping and block layer helpers to take care of IOMMU merging
for mmc plus subsequent fixups (Yoshihiro Shimoda)
- rework handling of the pgprot bits for remapping (me)
- take care of the dma direct infrastructure for swiotlb-xen (me)
- improve the dma noncoherent remapping infrastructure (me)
- better defaults for ->mmap, ->get_sgtable and ->get_required_mask
(me)
- cleanup mmaping of coherent DMA allocations (me)
- various misc cleanups (Andy Shevchenko, me)
* tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping: (41 commits)
mmc: renesas_sdhi_internal_dmac: Add MMC_CAP2_MERGE_CAPABLE
mmc: queue: Fix bigger segments usage
arm64: use asm-generic/dma-mapping.h
swiotlb-xen: merge xen_unmap_single into xen_swiotlb_unmap_page
swiotlb-xen: simplify cache maintainance
swiotlb-xen: use the same foreign page check everywhere
swiotlb-xen: remove xen_swiotlb_dma_mmap and xen_swiotlb_dma_get_sgtable
xen: remove the exports for xen_{create,destroy}_contiguous_region
xen/arm: remove xen_dma_ops
xen/arm: simplify dma_cache_maint
xen/arm: use dev_is_dma_coherent
xen/arm: consolidate page-coherent.h
xen/arm: use dma-noncoherent.h calls for xen-swiotlb cache maintainance
arm: remove wrappers for the generic dma remap helpers
dma-mapping: introduce a dma_common_find_pages helper
dma-mapping: always use VM_DMA_COHERENT for generic DMA remap
vmalloc: lift the arm flag for coherent mappings to common code
dma-mapping: provide a better default ->get_required_mask
dma-mapping: remove the dma_declare_coherent_memory export
remoteproc: don't allow modular build
...
The timer delayed for more than 3 seconds warning was triggered during
testing.
Workqueue: events_unbound sched_tick_remote
RIP: 0010:sched_tick_remote+0xee/0x100
...
Call Trace:
process_one_work+0x18c/0x3a0
worker_thread+0x30/0x380
kthread+0x113/0x130
ret_from_fork+0x22/0x40
The reason is that the code in collect_expired_timers() uses jiffies
unprotected:
if (next_event > jiffies)
base->clk = jiffies;
As the compiler is allowed to reload the value base->clk can advance
between the check and the store and in the worst case advance farther than
next event. That causes the timer expiry to be delayed until the wheel
pointer wraps around.
Convert the code to use READ_ONCE()
Fixes: 236968383c ("timers: Optimize collect_expired_timers() for NOHZ")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Liang ZhiCheng <liangzhicheng@baidu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1568894687-14499-1-git-send-email-lirongqing@baidu.com
Reject exactly same probe events as existing probes.
Multiprobe allows user to define multiple probes on same
event. If user appends a probe which exactly same definition
(same probe address and same arguments) on existing event,
the event will record same probe information twice.
That can be confusing users, so reject it.
Link: http://lkml.kernel.org/r/156879694602.31056.5533024778165036763.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fix to allow user to enable probe events on unloaded modules.
This operations was allowed before commit 60d53e2c3b ("tracing/probe:
Split trace_event related data from trace_probe"), because if users
need to probe module init functions, they have to enable those probe
events before loading module.
Link: http://lkml.kernel.org/r/156879693733.31056.9331322616994665167.stgit@devnote2
Cc: stable@vger.kernel.org
Fixes: 60d53e2c3b ("tracing/probe: Split trace_event related data from trace_probe")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
vmlinux BTF has enums that are 8 byte and 1 byte in size.
2 byte enum is a valid construct as well.
Fix BTF enum verification to accept those sizes.
Fixes: 69b693f0ae ("bpf: btf: Introduce BPF Type Format (BTF)")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Convert the bpf filesystem to the new internal mount API as the old
one will be obsoleted and removed. This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.
See Documentation/filesystems/mount_api.txt for more information.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Alexei Starovoitov <ast@kernel.org>
cc: Daniel Borkmann <daniel@iogearbox.net>
cc: Martin KaFai Lau <kafai@fb.com>
cc: Song Liu <songliubraving@fb.com>
cc: Yonghong Song <yhs@fb.com>
cc: netdev@vger.kernel.org
cc: bpf@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Before actually destrying a workqueue, destroy_workqueue() checks
whether it's actually idle. If it isn't, it prints out a bunch of
warning messages and leaves the workqueue dangling. It unfortunately
has a couple issues.
* Mayday list queueing increments pwq's refcnts which gets detected as
busy and fails the sanity checks. However, because mayday list
queueing is asynchronous, this condition can happen without any
actual work items left in the workqueue.
* Sanity check failure leaves the sysfs interface behind too which can
lead to init failure of newer instances of the workqueue.
This patch fixes the above two by
* If a workqueue has a rescuer, disable and kill the rescuer before
sanity checks. Disabling and killing is guaranteed to flush the
existing mayday list.
* Remove sysfs interface before sanity checks.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Marcin Pawlowski <mpawlowski@fb.com>
Reported-by: "Williams, Gerald S" <gerald.s.williams@intel.com>
Cc: stable@vger.kernel.org
Pull networking updates from David Miller:
1) Support IPV6 RA Captive Portal Identifier, from Maciej Żenczykowski.
2) Use bio_vec in the networking instead of custom skb_frag_t, from
Matthew Wilcox.
3) Make use of xmit_more in r8169 driver, from Heiner Kallweit.
4) Add devmap_hash to xdp, from Toke Høiland-Jørgensen.
5) Support all variants of 5750X bnxt_en chips, from Michael Chan.
6) More RTNL avoidance work in the core and mlx5 driver, from Vlad
Buslov.
7) Add TCP syn cookies bpf helper, from Petar Penkov.
8) Add 'nettest' to selftests and use it, from David Ahern.
9) Add extack support to drop_monitor, add packet alert mode and
support for HW drops, from Ido Schimmel.
10) Add VLAN offload to stmmac, from Jose Abreu.
11) Lots of devm_platform_ioremap_resource() conversions, from
YueHaibing.
12) Add IONIC driver, from Shannon Nelson.
13) Several kTLS cleanups, from Jakub Kicinski.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1930 commits)
mlxsw: spectrum_buffers: Add the ability to query the CPU port's shared buffer
mlxsw: spectrum: Register CPU port with devlink
mlxsw: spectrum_buffers: Prevent changing CPU port's configuration
net: ena: fix incorrect update of intr_delay_resolution
net: ena: fix retrieval of nonadaptive interrupt moderation intervals
net: ena: fix update of interrupt moderation register
net: ena: remove all old adaptive rx interrupt moderation code from ena_com
net: ena: remove ena_restore_ethtool_params() and relevant fields
net: ena: remove old adaptive interrupt moderation code from ena_netdev
net: ena: remove code duplication in ena_com_update_nonadaptive_moderation_interval _*()
net: ena: enable the interrupt_moderation in driver_supported_features
net: ena: reimplement set/get_coalesce()
net: ena: switch to dim algorithm for rx adaptive interrupt moderation
net: ena: add intr_moder_rx_interval to struct ena_com_dev and use it
net: phy: adin: implement Energy Detect Powerdown mode via phy-tunable
ethtool: implement Energy Detect Powerdown support via phy-tunable
xen-netfront: do not assume sk_buff_head list is empty in error handling
s390/ctcm: Delete unnecessary checks before the macro call “dev_kfree_skb”
net: ena: don't wake up tx queue when down
drop_monitor: Better sanitize notified packets
...
Pull crypto updates from Herbert Xu:
"API:
- Add the ability to abort a skcipher walk.
Algorithms:
- Fix XTS to actually do the stealing.
- Add library helpers for AES and DES for single-block users.
- Add library helpers for SHA256.
- Add new DES key verification helper.
- Add surrounding bits for ESSIV generator.
- Add accelerations for aegis128.
- Add test vectors for lzo-rle.
Drivers:
- Add i.MX8MQ support to caam.
- Add gcm/ccm/cfb/ofb aes support in inside-secure.
- Add ofb/cfb aes support in media-tek.
- Add HiSilicon ZIP accelerator support.
Others:
- Fix potential race condition in padata.
- Use unbound workqueues in padata"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (311 commits)
crypto: caam - Cast to long first before pointer conversion
crypto: ccree - enable CTS support in AES-XTS
crypto: inside-secure - Probe transform record cache RAM sizes
crypto: inside-secure - Base RD fetchcount on actual RD FIFO size
crypto: inside-secure - Base CD fetchcount on actual CD FIFO size
crypto: inside-secure - Enable extended algorithms on newer HW
crypto: inside-secure: Corrected configuration of EIP96_TOKEN_CTRL
crypto: inside-secure - Add EIP97/EIP197 and endianness detection
padata: remove cpu_index from the parallel_queue
padata: unbind parallel jobs from specific CPUs
padata: use separate workqueues for parallel and serial work
padata, pcrypt: take CPU hotplug lock internally in padata_alloc_possible
crypto: pcrypt - remove padata cpumask notifier
padata: make padata_do_parallel find alternate callback CPU
workqueue: require CPU hotplug read exclusion for apply_workqueue_attrs
workqueue: unconfine alloc/apply/free_workqueue_attrs()
padata: allocate workqueue internally
arm64: dts: imx8mq: Add CAAM node
random: Use wait_event_freezable() in add_hwgenerator_randomness()
crypto: ux500 - Fix COMPILE_TEST warnings
...
- Rework the main suspend-to-idle control flow to avoid repeating
"noirq" device resume and suspend operations in case of spurious
wakeups from the ACPI EC and decouple the ACPI EC wakeups support
from the LPS0 _DSM support (Rafael Wysocki).
- Extend the wakeup sources framework to expose wakeup sources as
device objects in sysfs (Tri Vo, Stephen Boyd).
- Expose system suspend statistics in sysfs (Kalesh Singh).
- Introduce a new haltpoll cpuidle driver and a new matching
governor for virtualized guests wanting to do guest-side polling
in the idle loop (Marcelo Tosatti, Joao Martins, Wanpeng Li,
Stephen Rothwell).
- Fix the menu and teo cpuidle governors to allow the scheduler tick
to be stopped if PM QoS is used to limit the CPU idle state exit
latency in some cases (Rafael Wysocki).
- Increase the resolution of the play_idle() argument to microseconds
for more fine-grained injection of CPU idle cycles (Daniel Lezcano).
- Switch over some users of cpuidle notifiers to the new QoS-based
frequency limits and drop the CPUFREQ_ADJUST and CPUFREQ_NOTIFY
policy notifier events (Viresh Kumar).
- Add new cpufreq driver based on nvmem for sun50i (Yangtao Li).
- Add support for MT8183 and MT8516 to the mediatek cpufreq driver
(Andrew-sh.Cheng, Fabien Parent).
- Add i.MX8MN support to the imx-cpufreq-dt cpufreq driver (Anson
Huang).
- Add qcs404 to cpufreq-dt-platdev blacklist (Jorge Ramirez-Ortiz).
- Update the qcom cpufreq driver (among other things, to make it
easier to extend and to use kryo cpufreq for other nvmem-based
SoCs) and add qcs404 support to it (Niklas Cassel, Douglas
RAILLARD, Sibi Sankar, Sricharan R).
- Fix assorted issues and make assorted minor improvements in the
cpufreq code (Colin Ian King, Douglas RAILLARD, Florian Fainelli,
Gustavo Silva, Hariprasad Kelam).
- Add new devfreq driver for NVidia Tegra20 (Dmitry Osipenko, Arnd
Bergmann).
- Add new Exynos PPMU events to devfreq events and extend that
mechanism (Lukasz Luba).
- Fix and clean up the exynos-bus devfreq driver (Kamil Konieczny).
- Improve devfreq documentation and governor code, fix spelling
typos in devfreq (Ezequiel Garcia, Krzysztof Kozlowski, Leonard
Crestez, MyungJoo Ham, Gaël PORTAY).
- Add regulators enable and disable to the OPP (operating performance
points) framework (Kamil Konieczny).
- Update the OPP framework to support multiple opp-suspend properties
(Anson Huang).
- Fix assorted issues and make assorted minor improvements in the OPP
code (Niklas Cassel, Viresh Kumar, Yue Hu).
- Clean up the generic power domains (genpd) framework (Ulf Hansson).
- Clean up assorted pieces of power management code and documentation
(Akinobu Mita, Amit Kucheria, Chuhong Yuan).
- Update the pm-graph tool to version 5.5 including multiple fixes
and improvements (Todd Brandt).
- Update the cpupower utility (Benjamin Weis, Geert Uytterhoeven,
Sébastien Szymanski).
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Merge tag 'pm-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"These include a rework of the main suspend-to-idle code flow (related
to the handling of spurious wakeups), a switch over of several users
of cpufreq notifiers to QoS-based limits, a new devfreq driver for
Tegra20, a new cpuidle driver and governor for virtualized guests, an
extension of the wakeup sources framework to expose wakeup sources as
device objects in sysfs, and more.
Specifics:
- Rework the main suspend-to-idle control flow to avoid repeating
"noirq" device resume and suspend operations in case of spurious
wakeups from the ACPI EC and decouple the ACPI EC wakeups support
from the LPS0 _DSM support (Rafael Wysocki).
- Extend the wakeup sources framework to expose wakeup sources as
device objects in sysfs (Tri Vo, Stephen Boyd).
- Expose system suspend statistics in sysfs (Kalesh Singh).
- Introduce a new haltpoll cpuidle driver and a new matching governor
for virtualized guests wanting to do guest-side polling in the idle
loop (Marcelo Tosatti, Joao Martins, Wanpeng Li, Stephen Rothwell).
- Fix the menu and teo cpuidle governors to allow the scheduler tick
to be stopped if PM QoS is used to limit the CPU idle state exit
latency in some cases (Rafael Wysocki).
- Increase the resolution of the play_idle() argument to microseconds
for more fine-grained injection of CPU idle cycles (Daniel
Lezcano).
- Switch over some users of cpuidle notifiers to the new QoS-based
frequency limits and drop the CPUFREQ_ADJUST and CPUFREQ_NOTIFY
policy notifier events (Viresh Kumar).
- Add new cpufreq driver based on nvmem for sun50i (Yangtao Li).
- Add support for MT8183 and MT8516 to the mediatek cpufreq driver
(Andrew-sh.Cheng, Fabien Parent).
- Add i.MX8MN support to the imx-cpufreq-dt cpufreq driver (Anson
Huang).
- Add qcs404 to cpufreq-dt-platdev blacklist (Jorge Ramirez-Ortiz).
- Update the qcom cpufreq driver (among other things, to make it
easier to extend and to use kryo cpufreq for other nvmem-based
SoCs) and add qcs404 support to it (Niklas Cassel, Douglas
RAILLARD, Sibi Sankar, Sricharan R).
- Fix assorted issues and make assorted minor improvements in the
cpufreq code (Colin Ian King, Douglas RAILLARD, Florian Fainelli,
Gustavo Silva, Hariprasad Kelam).
- Add new devfreq driver for NVidia Tegra20 (Dmitry Osipenko, Arnd
Bergmann).
- Add new Exynos PPMU events to devfreq events and extend that
mechanism (Lukasz Luba).
- Fix and clean up the exynos-bus devfreq driver (Kamil Konieczny).
- Improve devfreq documentation and governor code, fix spelling typos
in devfreq (Ezequiel Garcia, Krzysztof Kozlowski, Leonard Crestez,
MyungJoo Ham, Gaël PORTAY).
- Add regulators enable and disable to the OPP (operating performance
points) framework (Kamil Konieczny).
- Update the OPP framework to support multiple opp-suspend properties
(Anson Huang).
- Fix assorted issues and make assorted minor improvements in the OPP
code (Niklas Cassel, Viresh Kumar, Yue Hu).
- Clean up the generic power domains (genpd) framework (Ulf Hansson).
- Clean up assorted pieces of power management code and documentation
(Akinobu Mita, Amit Kucheria, Chuhong Yuan).
- Update the pm-graph tool to version 5.5 including multiple fixes
and improvements (Todd Brandt).
- Update the cpupower utility (Benjamin Weis, Geert Uytterhoeven,
Sébastien Szymanski)"
* tag 'pm-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (126 commits)
cpuidle-haltpoll: Enable kvm guest polling when dedicated physical CPUs are available
cpuidle-haltpoll: do not set an owner to allow modunload
cpuidle-haltpoll: return -ENODEV on modinit failure
cpuidle-haltpoll: set haltpoll as preferred governor
cpuidle: allow governor switch on cpuidle_register_driver()
PM: runtime: Documentation: add runtime_status ABI document
pm-graph: make setVal unbuffered again for python2 and python3
powercap: idle_inject: Use higher resolution for idle injection
cpuidle: play_idle: Increase the resolution to usec
cpuidle-haltpoll: vcpu hotplug support
cpufreq: Add qcs404 to cpufreq-dt-platdev blacklist
cpufreq: qcom: Add support for qcs404 on nvmem driver
cpufreq: qcom: Refactor the driver to make it easier to extend
cpufreq: qcom: Re-organise kryo cpufreq to use it for other nvmem based qcom socs
dt-bindings: opp: Add qcom-opp bindings with properties needed for CPR
dt-bindings: opp: qcom-nvmem: Support pstates provided by a power domain
Documentation: cpufreq: Update policy notifier documentation
cpufreq: Remove CPUFREQ_ADJUST and CPUFREQ_NOTIFY policy notifier events
PM / Domains: Verify PM domain type in dev_pm_genpd_set_performance_state()
PM / Domains: Simplify genpd_lookup_dev()
...
Pull cgroup updates from Tejun Heo:
"Three minor cleanup patches"
* 'for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
Use kvmalloc in cgroups-v1
cgroup: minor tweak for logic to get cgroup css
cgroup: Replace a seq_printf() call by seq_puts() in cgroup_print_ss_mask()
Pull core timer updates from Thomas Gleixner:
"Timers and timekeeping updates:
- A large overhaul of the posix CPU timer code which is a preparation
for moving the CPU timer expiry out into task work so it can be
properly accounted on the task/process.
An update to the bogus permission checks will come later during the
merge window as feedback was not complete before heading of for
travel.
- Switch the timerqueue code to use cached rbtrees and get rid of the
homebrewn caching of the leftmost node.
- Consolidate hrtimer_init() + hrtimer_init_sleeper() calls into a
single function
- Implement the separation of hrtimers to be forced to expire in hard
interrupt context even when PREEMPT_RT is enabled and mark the
affected timers accordingly.
- Implement a mechanism for hrtimers and the timer wheel to protect
RT against priority inversion and live lock issues when a (hr)timer
which should be canceled is currently executing the callback.
Instead of infinitely spinning, the task which tries to cancel the
timer blocks on a per cpu base expiry lock which is held and
released by the (hr)timer expiry code.
- Enable the Hyper-V TSC page based sched_clock for Hyper-V guests
resulting in faster access to timekeeping functions.
- Updates to various clocksource/clockevent drivers and their device
tree bindings.
- The usual small improvements all over the place"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits)
posix-cpu-timers: Fix permission check regression
posix-cpu-timers: Always clear head pointer on dequeue
hrtimer: Add a missing bracket and hide `migration_base' on !SMP
posix-cpu-timers: Make expiry_active check actually work correctly
posix-timers: Unbreak CONFIG_POSIX_TIMERS=n build
tick: Mark sched_timer to expire in hard interrupt context
hrtimer: Add kernel doc annotation for HRTIMER_MODE_HARD
x86/hyperv: Hide pv_ops access for CONFIG_PARAVIRT=n
posix-cpu-timers: Utilize timerqueue for storage
posix-cpu-timers: Move state tracking to struct posix_cputimers
posix-cpu-timers: Deduplicate rlimit handling
posix-cpu-timers: Remove pointless comparisons
posix-cpu-timers: Get rid of 64bit divisions
posix-cpu-timers: Consolidate timer expiry further
posix-cpu-timers: Get rid of zero checks
rlimit: Rewrite non-sensical RLIMIT_CPU comment
posix-cpu-timers: Respect INFINITY for hard RTTIME limit
posix-cpu-timers: Switch thread group sampling to array
posix-cpu-timers: Restructure expiry array
posix-cpu-timers: Remove cputime_expires
...
Pull core irq updates from Thomas Gleixner:
"Updates from the irq departement:
- Update the interrupt spreading code so it handles numa node with
different CPU counts properly.
- A large overhaul of the ARM GiCv3 driver to support new PPI and SPI
ranges.
- Conversion of all alloc_fwnode() users to use physical addresses
instead of virtual addresses so the virtual addresses are not
leaked. The physical address is sufficient to identify the
associated interrupt chip.
- Add support for Marvel MMP3, Amlogic Meson SM1 interrupt chips.
- Enforce interrupt threading at compile time if RT is enabled.
- Small updates and improvements all over the place"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
irqchip/gic-v3-its: Fix LPI release for Multi-MSI devices
irqchip/uniphier-aidet: Use devm_platform_ioremap_resource()
irqdomain: Add the missing assignment of domain->fwnode for named fwnode
irqchip/mmp: Coexist with GIC root IRQ controller
irqchip/mmp: Mask off interrupts from other cores
irqchip/mmp: Add missing chained_irq_{enter,exit}()
irqchip/mmp: Do not use of_address_to_resource() to get mux regs
irqchip/meson-gpio: Add support for meson sm1 SoCs
dt-bindings: interrupt-controller: New binding for the meson sm1 SoCs
genirq/affinity: Remove const qualifier from node_to_cpumask argument
genirq/affinity: Spread vectors on node according to nr_cpu ratio
genirq/affinity: Improve __irq_build_affinity_masks()
irqchip: Remove dev_err() usage after platform_get_irq()
irqchip: Add include guard to irq-partition-percpu.h
irqchip/mmp: Do not call irq_set_default_host() on DT platforms
irqchip/gic-v3-its: Remove the redundant set_bit for lpi_map
irqchip/gic-v3: Add quirks for HIP06/07 invalid GICD_TYPER erratum 161010803
irqchip/gic: Skip DT quirks when evaluating IIDR-based quirks
irqchip/gic-v3: Warn about inconsistent implementations of extended ranges
irqchip/gic-v3: Add EPPI range support
...
Pull CPU hotplug updates from Thomas Gleixner:
"A small update for the SMP hotplug code code:
- Track "booted once" CPUs in a cpumask so the x86 APIC code has an
easy way to decide whether broadcast IPIs are safe to use or not.
- Implement a cpumask_or_equal() helper for the IPI broadcast
evaluation.
The above two changes have been also pulled into the x86/apic
branch for implementing the conditional IPI broadcast feature.
- Cache the number of online CPUs instead of reevaluating it over and
over. num_online_cpus() is an unreliable snapshot anyway except
when it is used outside a cpu hotplug locked region. The cached
access is not changing this, but it's definitely faster than
calculating the bitmap wheight especially in hot paths"
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu/hotplug: Cache number of online CPUs
cpumask: Implement cpumask_or_equal()
smp/hotplug: Track booted once CPUs in a cpumask
Pull timer fix from Thomas Gleixner:
"A single fix to prevent the alarm timer code from returning ENOTSUPP
to user space.
ENOTSUPP is a purely kernel internal error code related to NFSv3 and
should never be handed back to user space. The risk for ABI breakage
is low as the number of systems which do not have a working RTC is
very limited"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
alarmtimer: Use EOPNOTSUPP instead of ENOTSUPP
Original changelog from Steve Rostedt (except last sentence which
explains the problem, and the Fixes: tag):
I performed a three way histogram with the following commands:
echo 'irq_lat u64 lat pid_t pid' > synthetic_events
echo 'wake_lat u64 lat u64 irqlat pid_t pid' >> synthetic_events
echo 'hist:keys=common_pid:irqts=common_timestamp.usecs if function == 0xffffffff81200580' > events/timer/hrtimer_start/trigger
echo 'hist:keys=common_pid:lat=common_timestamp.usecs-$irqts:onmatch(timer.hrtimer_start).irq_lat($lat,pid) if common_flags & 1' > events/sched/sched_waking/trigger
echo 'hist:keys=pid:wakets=common_timestamp.usecs,irqlat=lat' > events/synthetic/irq_lat/trigger
echo 'hist:keys=next_pid:lat=common_timestamp.usecs-$wakets,irqlat=$irqlat:onmatch(synthetic.irq_lat).wake_lat($lat,$irqlat,next_pid)' > events/sched/sched_switch/trigger
echo 1 > events/synthetic/wake_lat/enable
Basically I wanted to see:
hrtimer_start (calling function tick_sched_timer)
Note:
# grep tick_sched_timer /proc/kallsyms
ffffffff81200580 t tick_sched_timer
And save the time of that, and then record sched_waking if it is called
in interrupt context and with the same pid as the hrtimer_start, it
will record the latency between that and the waking event.
I then look at when the task that is woken is scheduled in, and record
the latency between the wakeup and the task running.
At the end, the wake_lat synthetic event will show the wakeup to
scheduled latency, as well as the irq latency in from hritmer_start to
the wakeup. The problem is that I found this:
<idle>-0 [007] d... 190.485261: wake_lat: lat=27 irqlat=190485230 pid=698
<idle>-0 [005] d... 190.485283: wake_lat: lat=40 irqlat=190485239 pid=10
<idle>-0 [002] d... 190.488327: wake_lat: lat=56 irqlat=190488266 pid=335
<idle>-0 [005] d... 190.489330: wake_lat: lat=64 irqlat=190489262 pid=10
<idle>-0 [003] d... 190.490312: wake_lat: lat=43 irqlat=190490265 pid=77
<idle>-0 [005] d... 190.493322: wake_lat: lat=54 irqlat=190493262 pid=10
<idle>-0 [005] d... 190.497305: wake_lat: lat=35 irqlat=190497267 pid=10
<idle>-0 [005] d... 190.501319: wake_lat: lat=50 irqlat=190501264 pid=10
The irqlat seemed quite large! Investigating this further, if I had
enabled the irq_lat synthetic event, I noticed this:
<idle>-0 [002] d.s. 249.429308: irq_lat: lat=164968 pid=335
<idle>-0 [002] d... 249.429369: wake_lat: lat=55 irqlat=249429308 pid=335
Notice that the timestamp of the irq_lat "249.429308" is awfully
similar to the reported irqlat variable. In fact, all instances were
like this. It appeared that:
irqlat=$irqlat
Wasn't assigning the old $irqlat to the new irqlat variable, but
instead was assigning the $irqts to it.
The issue is that assigning the old $irqlat to the new irqlat variable
creates a variable reference alias, but the alias creation code
forgets to make sure the alias uses the same var_ref_idx to access the
reference.
Link: http://lkml.kernel.org/r/1567375321.5282.12.camel@kernel.org
Cc: Linux Trace Devel <linux-trace-devel@vger.kernel.org>
Cc: linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: stable@vger.kernel.org
Fixes: 7e8b88a30b ("tracing: Add hist trigger support for variable reference aliases")
Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Function ftrace_lookup_ip() will check empty hash table. So we don't
need extra check outside.
Link: http://lkml.kernel.org/r/20190910143336.13472-1-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
cfs_rq_clock_task() was first introduced and used in:
f1b17280ef ("sched: Maintain runnable averages across throttled periods")
Over time its use has been graduately removed by the following commits:
d31b1a66cb ("sched/fair: Factorize PELT update")
2312729688 ("sched/fair: Update scale invariance of PELT")
Today, there is no single user left, so it can be safely removed.
Found via the -Wunused-function build warning.
Signed-off-by: Qian Cai <cai@lca.pw>
Cc: Ben Segall <bsegall@google.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/1568668775-2127-1-git-send-email-cai@lca.pw
[ Rewrote the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
* pm-opp:
PM / OPP: Correct Documentation about library location
opp: of: Support multiple suspend OPPs defined in DT
dt-bindings: opp: Support multiple opp-suspend properties
opp: core: add regulators enable and disable
opp: Don't decrement uninitialized list_kref
* pm-qos:
PM: QoS: Get rid of unused flags
* acpi-pm:
ACPI: PM: Print debug messages on device power state changes
* pm-domains:
PM / Domains: Verify PM domain type in dev_pm_genpd_set_performance_state()
PM / Domains: Simplify genpd_lookup_dev()
PM / Domains: Align in-parameter names for some genpd functions
* pm-tools:
pm-graph: make setVal unbuffered again for python2 and python3
cpupower: update German translation
tools/power/cpupower: fix 64bit detection when cross-compiling
cpupower: Add missing newline at end of file
pm-graph v5.5
* pm-cpufreq: (36 commits)
cpufreq: Add qcs404 to cpufreq-dt-platdev blacklist
cpufreq: qcom: Add support for qcs404 on nvmem driver
cpufreq: qcom: Refactor the driver to make it easier to extend
cpufreq: qcom: Re-organise kryo cpufreq to use it for other nvmem based qcom socs
dt-bindings: opp: Add qcom-opp bindings with properties needed for CPR
dt-bindings: opp: qcom-nvmem: Support pstates provided by a power domain
Documentation: cpufreq: Update policy notifier documentation
cpufreq: Remove CPUFREQ_ADJUST and CPUFREQ_NOTIFY policy notifier events
sched/cpufreq: Align trace event behavior of fast switching
ACPI: cpufreq: Switch to QoS requests instead of cpufreq notifier
video: pxafb: Remove cpufreq policy notifier
video: sa1100fb: Remove cpufreq policy notifier
arch_topology: Use CPUFREQ_CREATE_POLICY instead of CPUFREQ_NOTIFY
cpufreq: powerpc_cbe: Switch to QoS requests for freq limits
cpufreq: powerpc: macintosh: Switch to QoS requests for freq limits
cpufreq: Print driver name if cpufreq_suspend() fails
cpufreq: mediatek: Add support for mt8183
cpufreq: mediatek: change to regulator_get_optional
cpufreq: imx-cpufreq-dt: Add i.MX8MN support
cpufreq: Use imx-cpufreq-dt for i.MX8MN's speed grading
...
* pm-cpuidle:
cpuidle-haltpoll: Enable kvm guest polling when dedicated physical CPUs are available
cpuidle-haltpoll: do not set an owner to allow modunload
cpuidle-haltpoll: return -ENODEV on modinit failure
cpuidle-haltpoll: set haltpoll as preferred governor
cpuidle: allow governor switch on cpuidle_register_driver()
powercap: idle_inject: Use higher resolution for idle injection
cpuidle: play_idle: Increase the resolution to usec
cpuidle-haltpoll: vcpu hotplug support
cpuidle: teo: Get rid of redundant check in teo_update()
cpuidle: teo: Allow tick to be stopped if PM QoS is used
cpuidle: menu: Allow tick to be stopped if PM QoS is used
cpuidle: header file stubs must be "static inline"
cpuidle-haltpoll: disable host side polling when kvm virtualized
cpuidle: add haltpoll governor
governors: unify last_state_idx
cpuidle: add poll_limit_ns to cpuidle_device structure
add cpuidle-haltpoll driver
* pm-s2idle-rework: (21 commits)
ACPI: PM: s2idle: Always set up EC GPE for system wakeup
ACPI: PM: s2idle: Avoid rearming SCI for wakeup unnecessarily
PM: suspend: Fix platform_suspend_prepare_noirq()
intel-hid: Disable button array during suspend-to-idle
intel-hid: intel-vbtn: Avoid leaking wakeup_mode set
ACPI: PM: s2idle: Execute LPS0 _DSM functions with suspended devices
ACPI: EC: PM: Make acpi_ec_dispatch_gpe() print debug message
ACPI: EC: PM: Consolidate some code depending on PM_SLEEP
ACPI: PM: s2idle: Eliminate acpi_sleep_no_ec_events()
ACPI: PM: s2idle: Switch EC over to polling during "noirq" suspend
ACPI: PM: s2idle: Add acpi.sleep_no_lps0 module parameter
ACPI: PM: s2idle: Rearrange lps0_device_attach()
ACPI: PM: Set up EC GPE for system wakeup from drivers that need it
PM: sleep: Drop dpm_noirq_begin() and dpm_noirq_end()
PM: sleep: Integrate suspend-to-idle with generig suspend flow
PM: sleep: Simplify suspend-to-idle control flow
ACPI: PM: Set s2idle_wakeup earlier and clear it later
PM: sleep: Fix possible overflow in pm_system_cancel_wakeup()
ACPI: EC: Return bool from acpi_ec_dispatch_gpe()
ACPICA: Return u32 from acpi_dispatch_gpe()
...
Pull x86 cpu-feature updates from Ingo Molnar:
- Rework the Intel model names symbols/macros, which were decades of
ad-hoc extensions and added random noise. It's now a coherent, easy
to follow nomenclature.
- Add new Intel CPU model IDs:
- "Tiger Lake" desktop and mobile models
- "Elkhart Lake" model ID
- and the "Lightning Mountain" variant of Airmont, plus support code
- Add the new AVX512_VP2INTERSECT instruction to cpufeatures
- Remove Intel MPX user-visible APIs and the self-tests, because the
toolchain (gcc) is not supporting it going forward. This is the
first, lowest-risk phase of MPX removal.
- Remove X86_FEATURE_MFENCE_RDTSC
- Various smaller cleanups and fixes
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
x86/cpu: Update init data for new Airmont CPU model
x86/cpu: Add new Airmont variant to Intel family
x86/cpu: Add Elkhart Lake to Intel family
x86/cpu: Add Tiger Lake to Intel family
x86: Correct misc typos
x86/intel: Add common OPTDIFFs
x86/intel: Aggregate microserver naming
x86/intel: Aggregate big core graphics naming
x86/intel: Aggregate big core mobile naming
x86/intel: Aggregate big core client naming
x86/cpufeature: Explain the macro duplication
x86/ftrace: Remove mcount() declaration
x86/PCI: Remove superfluous returns from void functions
x86/msr-index: Move AMD MSRs where they belong
x86/cpu: Use constant definitions for CPU models
lib: Remove redundant ftrace flag removal
x86/crash: Remove unnecessary comparison
x86/bitops: Use __builtin_constant_p() directly instead of IS_IMMEDIATE()
x86: Remove X86_FEATURE_MFENCE_RDTSC
x86/mpx: Remove MPX APIs
...
Pull scheduler updates from Ingo Molnar:
- MAINTAINERS: Add Mark Rutland as perf submaintainer, Juri Lelli and
Vincent Guittot as scheduler submaintainers. Add Dietmar Eggemann,
Steven Rostedt, Ben Segall and Mel Gorman as scheduler reviewers.
As perf and the scheduler is getting bigger and more complex,
document the status quo of current responsibilities and interests,
and spread the review pain^H^H^H^H fun via an increase in the Cc:
linecount generated by scripts/get_maintainer.pl. :-)
- Add another series of patches that brings the -rt (PREEMPT_RT) tree
closer to mainline: split the monolithic CONFIG_PREEMPT dependencies
into a new CONFIG_PREEMPTION category that will allow the eventual
introduction of CONFIG_PREEMPT_RT. Still a few more hundred patches
to go though.
- Extend the CPU cgroup controller with uclamp.min and uclamp.max to
allow the finer shaping of CPU bandwidth usage.
- Micro-optimize energy-aware wake-ups from O(CPUS^2) to O(CPUS).
- Improve the behavior of high CPU count, high thread count
applications running under cpu.cfs_quota_us constraints.
- Improve balancing with SCHED_IDLE (SCHED_BATCH) tasks present.
- Improve CPU isolation housekeeping CPU allocation NUMA locality.
- Fix deadline scheduler bandwidth calculations and logic when cpusets
rebuilds the topology, or when it gets deadline-throttled while it's
being offlined.
- Convert the cpuset_mutex to percpu_rwsem, to allow it to be used from
setscheduler() system calls without creating global serialization.
Add new synchronization between cpuset topology-changing events and
the deadline acceptance tests in setscheduler(), which were broken
before.
- Rework the active_mm state machine to be less confusing and more
optimal.
- Rework (simplify) the pick_next_task() slowpath.
- Improve load-balancing on AMD EPYC systems.
- ... and misc cleanups, smaller fixes and improvements - please see
the Git log for more details.
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
sched/psi: Correct overly pessimistic size calculation
sched/fair: Speed-up energy-aware wake-ups
sched/uclamp: Always use 'enum uclamp_id' for clamp_id values
sched/uclamp: Update CPU's refcount on TG's clamp changes
sched/uclamp: Use TG's clamps to restrict TASK's clamps
sched/uclamp: Propagate system defaults to the root group
sched/uclamp: Propagate parent clamps
sched/uclamp: Extend CPU's cgroup controller
sched/topology: Improve load balancing on AMD EPYC systems
arch, ia64: Make NUMA select SMP
sched, perf: MAINTAINERS update, add submaintainers and reviewers
sched/fair: Use rq_lock/unlock in online_fair_sched_group
cpufreq: schedutil: fix equation in comment
sched: Rework pick_next_task() slow-path
sched: Allow put_prev_task() to drop rq->lock
sched/fair: Expose newidle_balance()
sched: Add task_struct pointer to sched_class::set_curr_task
sched: Rework CPU hotplug task selection
sched/{rt,deadline}: Fix set_next_task vs pick_next_task
sched: Fix kerneldoc comment for ia64_set_curr_task
...
Pull perf updates from Ingo Molnar:
"Kernel side changes:
- Improved kbprobes robustness
- Intel PEBS support for PT hardware tracing
- Other Intel PT improvements: high order pages memory footprint
reduction and various related cleanups
- Misc cleanups
The perf tooling side has been very busy in this cycle, with over 300
commits. This is an incomplete high-level summary of the many
improvements done by over 30 developers:
- Lots of updates to the following tools:
'perf c2c'
'perf config'
'perf record'
'perf report'
'perf script'
'perf test'
'perf top'
'perf trace'
- Updates to libperf and libtraceevent, and a consolidation of the
proliferation of x86 instruction decoder libraries.
- Vendor event updates for Intel and PowerPC CPUs,
- Updates to hardware tracing tooling for ARM and Intel CPUs,
- ... and lots of other changes and cleanups - see the shortlog and
Git log for details"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (322 commits)
kprobes: Prohibit probing on BUG() and WARN() address
perf/x86: Make more stuff static
x86, perf: Fix the dependency of the x86 insn decoder selftest
objtool: Ignore intentional differences for the x86 insn decoder
objtool: Update sync-check.sh from perf's check-headers.sh
perf build: Ignore intentional differences for the x86 insn decoder
perf intel-pt: Use shared x86 insn decoder
perf intel-pt: Remove inat.c from build dependency list
perf: Update .gitignore file
objtool: Move x86 insn decoder to a common location
perf metricgroup: Support multiple events for metricgroup
perf metricgroup: Scale the metric result
perf pmu: Change convert_scale from static to global
perf symbols: Move mem_info and branch_info out of symbol.h
perf auxtrace: Uninline functions that touch perf_session
perf tools: Remove needless evlist.h include directives
perf tools: Remove needless evlist.h include directives
perf tools: Remove needless thread_map.h include directives
perf tools: Remove needless thread.h include directives
perf tools: Remove needless map.h include directives
...
Pull locking updates from Ingo Molnar:
- improve rwsem scalability
- add uninitialized rwsem debugging check
- reduce lockdep's stacktrace memory usage and add diagnostics
- misc cleanups, code consolidation and constification
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
mutex: Fix up mutex_waiter usage
locking/mutex: Use mutex flags macro instead of hard code
locking/mutex: Make __mutex_owner static to mutex.c
locking/qspinlock,x86: Clarify virt_spin_lock_key
locking/rwsem: Check for operations on an uninitialized rwsem
locking/rwsem: Make handoff writer optimistically spin on owner
locking/lockdep: Report more stack trace statistics
locking/lockdep: Reduce space occupied by stack traces
stacktrace: Constify 'entries' arguments
locking/lockdep: Make it clear that what lock_class::key points at is not modified
Pull RCU updates from Ingo Molnar:
"This cycle's RCU changes were:
- A few more RCU flavor consolidation cleanups.
- Updates to RCU's list-traversal macros improving lockdep usability.
- Forward-progress improvements for no-CBs CPUs: Avoid ignoring
incoming callbacks during grace-period waits.
- Forward-progress improvements for no-CBs CPUs: Use ->cblist
structure to take advantage of others' grace periods.
- Also added a small commit that avoids needlessly inflicting
scheduler-clock ticks on callback-offloaded CPUs.
- Forward-progress improvements for no-CBs CPUs: Reduce contention on
->nocb_lock guarding ->cblist.
- Forward-progress improvements for no-CBs CPUs: Add ->nocb_bypass
list to further reduce contention on ->nocb_lock guarding ->cblist.
- Miscellaneous fixes.
- Torture-test updates.
- minor LKMM updates"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (86 commits)
MAINTAINERS: Update from paulmck@linux.ibm.com to paulmck@kernel.org
rcu: Don't include <linux/ktime.h> in rcutiny.h
rcu: Allow rcu_do_batch() to dynamically adjust batch sizes
rcu/nocb: Don't wake no-CBs GP kthread if timer posted under overload
rcu/nocb: Reduce __call_rcu_nocb_wake() leaf rcu_node ->lock contention
rcu/nocb: Reduce nocb_cb_wait() leaf rcu_node ->lock contention
rcu/nocb: Advance CBs after merge in rcutree_migrate_callbacks()
rcu/nocb: Avoid synchronous wakeup in __call_rcu_nocb_wake()
rcu/nocb: Print no-CBs diagnostics when rcutorture writer unduly delayed
rcu/nocb: EXP Check use and usefulness of ->nocb_lock_contended
rcu/nocb: Add bypass callback queueing
rcu/nocb: Atomic ->len field in rcu_segcblist structure
rcu/nocb: Unconditionally advance and wake for excessive CBs
rcu/nocb: Reduce ->nocb_lock contention with separate ->nocb_gp_lock
rcu/nocb: Reduce contention at no-CBs invocation-done time
rcu/nocb: Reduce contention at no-CBs registry-time CB advancement
rcu/nocb: Round down for number of no-CBs grace-period kthreads
rcu/nocb: Avoid ->nocb_lock capture by corresponding CPU
rcu/nocb: Avoid needless wakeups of no-CBs grace-period kthread
rcu/nocb: Make __call_rcu_nocb_wake() safe for many callbacks
...
Pull parisc updates from Helge Deller:
- Make the powerpc implementation to read elf files available as a
public kexec interface so it can be re-used on other architectures
(Sven)
- Implement kexec on parisc (Sven)
- Add kprobes on ftrace on parisc (Sven)
- Fix kernel crash with HSC-PCI cards based on card-mode Dino
- Add assembly implementations for memset, strlen, strcpy, strncpy and
strcat
- Some cleanups, documentation updates, warning fixes, ...
* 'parisc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: (25 commits)
parisc: Have git ignore generated real2.S and firmware.c
parisc: Disable HP HSC-PCI Cards to prevent kernel crash
parisc: add support for kexec_file_load() syscall
parisc: wire up kexec_file_load syscall
parisc: add kexec syscall support
parisc: add __pdc_cpu_rendezvous()
kprobes/parisc: remove arch_kprobe_on_func_entry()
kexec_elf: support 32 bit ELF files
kexec_elf: remove unused variable in kexec_elf_load()
kexec_elf: remove Elf_Rel macro
kexec_elf: remove PURGATORY_STACK_SIZE
kexec_elf: remove parsing of section headers
kexec_elf: change order of elf_*_to_cpu() functions
kexec: add KEXEC_ELF
parisc: Save some bytes in dino driver
parisc: Drop comments which are already in pci.h
parisc: Convert eisa_enumerator to use pr_cont()
parisc: Avoid warning when loading hppb driver
parisc: speed up flush_tlb_all_local with qemu
parisc: Add ALTERNATIVE_CODE() and ALT_COND_RUN_ON_QEMU
...
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Merge tag 'please-pull-ia64_for_5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux
Pull ia64 updates from Tony Luck:
"The big change here is removal of support for SGI Altix"
* tag 'please-pull-ia64_for_5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux: (33 commits)
genirq: remove the is_affinity_mask_valid hook
ia64: remove CONFIG_SWIOTLB ifdefs
ia64: remove support for machvecs
ia64: move the screen_info setup to common code
ia64: move the ROOT_DEV setup to common code
ia64: rework iommu probing
ia64: remove the unused sn_coherency_id symbol
ia64: remove the SGI UV simulator support
ia64: remove the zx1 swiotlb machvec
ia64: remove CONFIG_ACPI ifdefs
ia64: remove CONFIG_PCI ifdefs
ia64: remove the hpsim platform
ia64: remove now unused machvec indirections
ia64: remove support for the SGI SN2 platform
drivers: remove the SGI SN2 IOC4 base support
drivers: remove the SGI SN2 IOC3 base support
qla2xxx: remove SGI SN2 support
qla1280: remove SGI SN2 support
misc/sgi-xp: remove SGI SN2 support
char/mspec: remove SGI SN2 support
...
- 52-bit virtual addressing in the kernel
- New ABI to allow tagged user pointers to be dereferenced by syscalls
- Early RNG seeding by the bootloader
- Improve robustness of SMP boot
- Fix TLB invalidation in light of recent architectural clarifications
- Support for i.MX8 DDR PMU
- Remove direct LSE instruction patching in favour of static keys
- Function error injection using kprobes
- Support for the PPTT "thread" flag introduced by ACPI 6.3
- Move PSCI idle code into proper cpuidle driver
- Relaxation of implicit I/O memory barriers
- Build with RELR relocations when toolchain supports them
- Numerous cleanups and non-critical fixes
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
"Although there isn't tonnes of code in terms of line count, there are
a fair few headline features which I've noted both in the tag and also
in the merge commits when I pulled everything together.
The part I'm most pleased with is that we had 35 contributors this
time around, which feels like a big jump from the usual small group of
core arm64 arch developers. Hopefully they all enjoyed it so much that
they'll continue to contribute, but we'll see.
It's probably worth highlighting that we've pulled in a branch from
the risc-v folks which moves our CPU topology code out to where it can
be shared with others.
Summary:
- 52-bit virtual addressing in the kernel
- New ABI to allow tagged user pointers to be dereferenced by
syscalls
- Early RNG seeding by the bootloader
- Improve robustness of SMP boot
- Fix TLB invalidation in light of recent architectural
clarifications
- Support for i.MX8 DDR PMU
- Remove direct LSE instruction patching in favour of static keys
- Function error injection using kprobes
- Support for the PPTT "thread" flag introduced by ACPI 6.3
- Move PSCI idle code into proper cpuidle driver
- Relaxation of implicit I/O memory barriers
- Build with RELR relocations when toolchain supports them
- Numerous cleanups and non-critical fixes"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (114 commits)
arm64: remove __iounmap
arm64: atomics: Use K constraint when toolchain appears to support it
arm64: atomics: Undefine internal macros after use
arm64: lse: Make ARM64_LSE_ATOMICS depend on JUMP_LABEL
arm64: asm: Kill 'asm/atomic_arch.h'
arm64: lse: Remove unused 'alt_lse' assembly macro
arm64: atomics: Remove atomic_ll_sc compilation unit
arm64: avoid using hard-coded registers for LSE atomics
arm64: atomics: avoid out-of-line ll/sc atomics
arm64: Use correct ll/sc atomic constraints
jump_label: Don't warn on __exit jump entries
docs/perf: Add documentation for the i.MX8 DDR PMU
perf/imx_ddr: Add support for AXI ID filtering
arm64: kpti: ensure patched kernel text is fetched from PoU
arm64: fix fixmap copy for 16K pages and 48-bit VA
perf/smmuv3: Validate groups for global filtering
perf/smmuv3: Validate group size
arm64: Relax Documentation/arm64/tagged-pointers.rst
arm64: kvm: Replace hardcoded '1' with SYS_PAR_EL1_F
arm64: mm: Ignore spurious translation faults taken from the kernel
...
Including:
- Batched unmap support for the IOMMU-API
- Support for unlocked command queueing in the ARM-SMMU driver
- Rework the ATS support in the ARM-SMMU driver
- More refactoring in the ARM-SMMU driver to support hardware
implemention specific quirks and errata
- Bounce buffering DMA-API implementatation in the Intel VT-d driver
for untrusted devices (like Thunderbolt devices)
- Fixes for runtime PM support in the OMAP iommu driver
- MT8183 IOMMU support in the Mediatek IOMMU driver
- Rework of the way the IOMMU core sets the default domain type for
groups. Changing the default domain type on x86 does not require two
kernel parameters anymore.
- More smaller fixes and cleanups
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Merge tag 'iommu-updates-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull iommu updates from Joerg Roedel:
- batched unmap support for the IOMMU-API
- support for unlocked command queueing in the ARM-SMMU driver
- rework the ATS support in the ARM-SMMU driver
- more refactoring in the ARM-SMMU driver to support hardware
implemention specific quirks and errata
- bounce buffering DMA-API implementatation in the Intel VT-d driver
for untrusted devices (like Thunderbolt devices)
- fixes for runtime PM support in the OMAP iommu driver
- MT8183 IOMMU support in the Mediatek IOMMU driver
- rework of the way the IOMMU core sets the default domain type for
groups. Changing the default domain type on x86 does not require two
kernel parameters anymore.
- more smaller fixes and cleanups
* tag 'iommu-updates-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (113 commits)
iommu/vt-d: Declare Broadwell igfx dmar support snafu
iommu/vt-d: Add Scalable Mode fault information
iommu/vt-d: Use bounce buffer for untrusted devices
iommu/vt-d: Add trace events for device dma map/unmap
iommu/vt-d: Don't switch off swiotlb if bounce page is used
iommu/vt-d: Check whether device requires bounce buffer
swiotlb: Split size parameter to map/unmap APIs
iommu/omap: Mark pm functions __maybe_unused
iommu/ipmmu-vmsa: Disable cache snoop transactions on R-Car Gen3
iommu/ipmmu-vmsa: Move IMTTBCR_SL0_TWOBIT_* to restore sort order
iommu: Don't use sme_active() in generic code
iommu/arm-smmu-v3: Fix build error without CONFIG_PCI_ATS
iommu/qcom: Use struct_size() helper
iommu: Remove wrong default domain comments
iommu/dma: Fix for dereferencing before null checking
iommu/mediatek: Clean up struct mtk_smi_iommu
memory: mtk-smi: Get rid of need_larbid
iommu/mediatek: Fix VLD_PA_RNG register backup when suspend
memory: mtk-smi: Add bus_sel for mt8183
memory: mtk-smi: Invoke pm runtime_callback to enable clocks
...
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Merge tag 'core-process-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull pidfd/waitid updates from Christian Brauner:
"This contains two features and various tests.
First, it adds support for waiting on process through pidfds by adding
the P_PIDFD type to the waitid() syscall. This completes the basic
functionality of the pidfd api (cf. [1]). In the meantime we also have
a new adition to the userspace projects that make use of the pidfd
api. The qt project was nice enough to send a mail pointing out that
they have a pr up to switch to the pidfd api (cf. [2]).
Second, this tag contains an extension to the waitid() syscall to make
it possible to wait on the current process group in a race free manner
(even though the actual problem is very unlikely) by specifing 0
together with the P_PGID type. This extension traces back to a
discussion on the glibc development mailing list.
There are also a range of tests for the features above. Additionally,
the test-suite which detected the pidfd-polling race we fixed in [3]
is included in this tag"
[1] https://lwn.net/Articles/794707/
[2] https://codereview.qt-project.org/c/qt/qtbase/+/108456
[3] commit b191d6491b ("pidfd: fix a poll race when setting exit_state")
* tag 'core-process-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
waitid: Add support for waiting for the current process group
tests: add pidfd poll tests
tests: move common definitions and functions into pidfd.h
pidfd: add pidfd_wait tests
pidfd: add P_PIDFD to waitid()
Daniel Borkmann says:
====================
pull-request: bpf-next 2019-09-16
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Now that initial BPF backend for gcc has been merged upstream, enable
BPF kselftest suite for bpf-gcc. Also fix a BE issue with access to
bpf_sysctl.file_pos, from Ilya.
2) Follow-up fix for link-vmlinux.sh to remove bash-specific extensions
related to recent work on exposing BTF info through sysfs, from Andrii.
3) AF_XDP zero copy fixes for i40e and ixgbe driver which caused umem
headroom to be added twice, from Ciara.
4) Refactoring work to convert sock opt tests into test_progs framework
in BPF kselftests, from Stanislav.
5) Fix a general protection fault in dev_map_hash_update_elem(), from Toke.
6) Cleanup to use BPF_PROG_RUN() macro in KCM, from Sami.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
"ctx:file_pos sysctl:read write ok" fails on s390 with "Read value !=
nux". This is because verifier rewrites a complete 32-bit
bpf_sysctl.file_pos update to a partial update of the first 32 bits of
64-bit *bpf_sysctl_kern.ppos, which is not correct on big-endian
systems.
Fix by using an offset on big-endian systems.
Ditto for bpf_sysctl.file_pos reads. Currently the test does not detect
a problem there, since it expects to see 0, which it gets with high
probability in error cases, so change it to seek to offset 3 and expect
3 in bpf_sysctl.file_pos.
Fixes: e1550bfe0d ("bpf: Add file_pos field to bpf_sysctl ctx")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20190816105300.49035-1-iii@linux.ibm.com/
syzbot found a crash in dev_map_hash_update_elem(), when replacing an
element with a new one. Jesper correctly identified the cause of the crash
as a race condition between the initial lookup in the map (which is done
before taking the lock), and the removal of the old element.
Rather than just add a second lookup into the hashmap after taking the
lock, fix this by reworking the function logic to take the lock before the
initial lookup.
Fixes: 6f9d451ab1 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
Reported-and-tested-by: syzbot+4e7a85b1432052e8d6f8@syzkaller.appspotmail.com
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
We do need to call the constructors for *modules*, and
at least for KASAN in the future, we must call even the
kernel constructors only later when the kernel has been
initialized.
Instead of relying on libc to call them, emit an empty
section for libc and let the kernel's CONSTRUCTORS code
do the rest of the job.
Tested that it indeed doesn't work in modules, and does
work after the fixes in both, with a few functions with
__attribute__((constructor)) in both dynamic and static
builds.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Pull networking fixes from David Miller:
1) Don't corrupt xfrm_interface parms before validation, from Nicolas
Dichtel.
2) Revert use of usb-wakeup in btusb, from Mario Limonciello.
3) Block ipv6 packets in bridge netfilter if ipv6 is disabled, from
Leonardo Bras.
4) IPS_OFFLOAD not honored in ctnetlink, from Pablo Neira Ayuso.
5) Missing ULP check in sock_map, from John Fastabend.
6) Fix receive statistic handling in forcedeth, from Zhu Yanjun.
7) Fix length of SKB allocated in 6pack driver, from Christophe
JAILLET.
8) ip6_route_info_create() returns an error pointer, not NULL. From
Maciej Żenczykowski.
9) Only add RDS sock to the hashes after rs_transport is set, from
Ka-Cheong Poon.
10) Don't double clean TX descriptors in ixgbe, from Ilya Maximets.
11) Presence of transmit IPSEC offload in an SKB is not tested for
correctly in ixgbe and ixgbevf. From Steffen Klassert and Jeff
Kirsher.
12) Need rcu_barrier() when register_netdevice() takes one of the
notifier based failure paths, from Subash Abhinov Kasiviswanathan.
13) Fix leak in sctp_do_bind(), from Mao Wenan.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (72 commits)
cdc_ether: fix rndis support for Mediatek based smartphones
sctp: destroy bucket if failed to bind addr
sctp: remove redundant assignment when call sctp_get_port_local
sctp: change return type of sctp_get_port_local
ixgbevf: Fix secpath usage for IPsec Tx offload
sctp: Fix the link time qualifier of 'sctp_ctrlsock_exit()'
ixgbe: Fix secpath usage for IPsec TX offload.
net: qrtr: fix memort leak in qrtr_tun_write_iter
net: Fix null de-reference of device refcount
ipv6: Fix the link time qualifier of 'ping_v6_proc_exit_net()'
tun: fix use-after-free when register netdev failed
tcp: fix tcp_ecn_withdraw_cwr() to clear TCP_ECN_QUEUE_CWR
ixgbe: fix double clean of Tx descriptors with xdp
ixgbe: Prevent u8 wrapping of ITR value to something less than 10us
mlx4: fix spelling mistake "veify" -> "verify"
net: hns3: fix spelling mistake "undeflow" -> "underflow"
net: lmc: fix spelling mistake "runnin" -> "running"
NFC: st95hf: fix spelling mistake "receieve" -> "receive"
net/rds: An rds_sock is added too early to the hash table
mac80211: Do not send Layer 2 Update frame before authorization
...
With the removal of the ENODATA case from padata_get_next, the cpu_index
field is no longer useful, so it can go away.
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Padata binds the parallel part of a job to a single CPU and round-robins
over all CPUs in the system for each successive job. Though the serial
parts rely on per-CPU queues for correct ordering, they're not necessary
for parallel work, and it improves performance to run the job locally on
NUMA machines and let the scheduler pick the CPU within a node on a busy
system.
So, make the parallel workqueue unbound.
Update the parallel workqueue's cpumask when the instance's parallel
cpumask changes.
Now that parallel jobs no longer run on max_active=1 workqueues, two or
more parallel works that hash to the same CPU may run simultaneously,
finish out of order, and so be serialized out of order. Prevent this by
keeping the works sorted on the reorder list by sequence number and
checking that in the reordering logic.
padata_get_next becomes padata_find_next so it can be reused for the end
of padata_reorder, where it's used to avoid uselessly queueing work when
the next job by sequence number isn't finished yet but a later job that
hashed to the same CPU has.
The ENODATA case in padata_find_next no longer makes sense because
parallel jobs aren't bound to specific CPUs. The EINPROGRESS case takes
care of the scenario where a parallel job is potentially running on the
same CPU as padata_find_next, and with only one error code left, just
use NULL instead.
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
padata currently uses one per-CPU workqueue per instance for all work.
Prepare for running parallel jobs on an unbound workqueue by introducing
dedicated workqueues for parallel and serial work.
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
With pcrypt's cpumask no longer used, take the CPU hotplug lock inside
padata_alloc_possible.
Useful later in the series for avoiding nested acquisition of the CPU
hotplug lock in padata when padata_alloc_possible is allocating an
unbound workqueue.
Without this patch, this nested acquisition would happen later in the
series:
pcrypt_init_padata
get_online_cpus
alloc_padata_possible
alloc_padata
alloc_workqueue(WQ_UNBOUND) // later in the series
alloc_and_link_pwqs
apply_wqattrs_lock
get_online_cpus // recursive rwsem acquisition
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
padata_do_parallel currently returns -EINVAL if the callback CPU isn't
in the callback cpumask.
pcrypt tries to prevent this situation by keeping its own callback
cpumask in sync with padata's and checks that the callback CPU it passes
to padata is valid. Make padata handle this instead.
padata_do_parallel now takes a pointer to the callback CPU and updates
it for the caller if an alternate CPU is used. Overall behavior in
terms of which callback CPUs are chosen stays the same.
Prepares for removal of the padata cpumask notifier in pcrypt, which
will fix a lockdep complaint about nested acquisition of the CPU hotplug
lock later in the series.
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Change the calling convention for apply_workqueue_attrs to require CPU
hotplug read exclusion.
Avoids lockdep complaints about nested calls to get_online_cpus in a
future patch where padata calls apply_workqueue_attrs when changing
other CPU-hotplug-sensitive data structures with the CPU read lock
already held.
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
padata will use these these interfaces in a later patch, so unconfine them.
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Move workqueue allocation inside of padata to prepare for further
changes to how padata uses workqueues.
Guarantees the workqueue is created with max_active=1, which padata
relies on to work correctly. No functional change.
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-crypto@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
EAS computes the energy impact of migrating a waking task when deciding
on which CPU it should run. However, the current approach is known to
have a high algorithmic complexity, which can result in prohibitively
high wake-up latencies on systems with complex energy models, such as
systems with per-CPU DVFS. On such systems, the algorithm complexity is
in O(n^2) (ignoring the cost of searching for performance states in the
EM) with 'n' the number of CPUs.
To address this, re-factor the EAS wake-up path to compute the energy
'delta' (with and without the task) on a per-performance domain basis,
rather than system-wide, which brings the complexity down to O(n).
No functional changes intended.
Test results
~~~~~~~~~~~~
* Setup: Tested on a Google Pixel 3, with a Snapdragon 845 (4+4 CPUs,
A55/A75). Base kernel is 5.3-rc5 + Pixel3 specific patches. Android
userspace, no graphics.
* Test case: Run a periodic rt-app task, with 16ms period, ramping down
from 70% to 10%, in 5% steps of 500 ms each (json avail. at [1]).
Frequencies of all CPUs are pinned to max (using scaling_min_freq
CPUFreq sysfs entries) to reduce variability. The time to run
select_task_rq_fair() is measured using the function profiler
(/sys/kernel/debug/tracing/trace_stat/function*). See the test script
for more details [2].
Test 1:
I hacked the DT to 'fake' per-CPU DVFS. That is, we end up with one
CPUFreq policy per CPU (8 policies in total). Since all frequencies are
pinned to max for the test, this should have no impact on the actual
frequency selection, but it does in the EAS calculation.
+---------------------------+----------------------------------+
| Without patch | With patch |
+-----+-----+----------+----------+-----+-----------------+----------+
| CPU | Hit | Avg (us) | s^2 (us) | Hit | Avg (us) | s^2 (us) |
|-----+-----+----------+----------+-----+-----------------+----------+
| 0 | 274 | 38.303 | 1750.239 | 401 | 14.126 (-63.1%) | 146.625 |
| 1 | 197 | 49.529 | 1695.852 | 314 | 16.135 (-67.4%) | 167.525 |
| 2 | 142 | 34.296 | 1758.665 | 302 | 14.133 (-58.8%) | 130.071 |
| 3 | 172 | 31.734 | 1490.975 | 641 | 14.637 (-53.9%) | 139.189 |
| 4 | 316 | 7.834 | 178.217 | 425 | 5.413 (-30.9%) | 20.803 |
| 5 | 447 | 8.424 | 144.638 | 556 | 5.929 (-29.6%) | 27.301 |
| 6 | 581 | 14.886 | 346.793 | 456 | 5.711 (-61.6%) | 23.124 |
| 7 | 456 | 10.005 | 211.187 | 997 | 4.708 (-52.9%) | 21.144 |
+-----+-----+----------+----------+-----+-----------------+----------+
* Hit, Avg and s^2 are as reported by the function profiler
Test 2:
I also ran the same test with a normal DT, with 2 CPUFreq policies, to
see if this causes regressions in the most common case.
+---------------------------+----------------------------------+
| Without patch | With patch |
+-----+-----+----------+----------+-----+-----------------+----------+
| CPU | Hit | Avg (us) | s^2 (us) | Hit | Avg (us) | s^2 (us) |
|-----+-----+----------+----------+-----+-----------------+----------+
| 0 | 345 | 22.184 | 215.321 | 580 | 18.635 (-16.0%) | 146.892 |
| 1 | 358 | 18.597 | 200.596 | 438 | 12.934 (-30.5%) | 104.604 |
| 2 | 359 | 25.566 | 200.217 | 397 | 10.826 (-57.7%) | 74.021 |
| 3 | 362 | 16.881 | 200.291 | 718 | 11.455 (-32.1%) | 102.280 |
| 4 | 457 | 3.822 | 9.895 | 757 | 4.616 (+20.8%) | 13.369 |
| 5 | 344 | 4.301 | 7.121 | 594 | 5.320 (+23.7%) | 18.798 |
| 6 | 472 | 4.326 | 7.849 | 464 | 5.648 (+30.6%) | 22.022 |
| 7 | 331 | 4.630 | 13.937 | 408 | 5.299 (+14.4%) | 18.273 |
+-----+-----+----------+----------+-----+-----------------+----------+
* Hit, Avg and s^2 are as reported by the function profiler
In addition to these two tests, I also ran 50 iterations of the Lisa
EAS functional test suite [3] with this patch applied on Arm Juno r0,
Arm Juno r2, Arm TC2 and Hikey960, and could not see any regressions
(all EAS functional tests are passing).
[1] https://paste.debian.net/1100055/
[2] https://paste.debian.net/1100057/
[3] https://github.com/ARM-software/lisa/blob/master/lisa/tests/scheduler/eas_behaviour.py
Signed-off-by: Quentin Perret <quentin.perret@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dietmar.eggemann@arm.com
Cc: juri.lelli@redhat.com
Cc: morten.rasmussen@arm.com
Cc: qais.yousef@arm.com
Cc: qperret@qperret.net
Cc: rjw@rjwysocki.net
Cc: tkjos@google.com
Cc: valentin.schneider@arm.com
Cc: vincent.guittot@linaro.org
Link: https://lkml.kernel.org/r/20190912094404.13802-1-qperret@qperret.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If a new child cgroup is created in the frozen cgroup hierarchy
(one or more of ancestor cgroups is frozen), the CGRP_FREEZE cgroup
flag should be set. Otherwise if a process will be attached to the
child cgroup, it won't become frozen.
The problem can be reproduced with the test_cgfreezer_mkdir test.
This is the output before this patch:
~/test_freezer
ok 1 test_cgfreezer_simple
ok 2 test_cgfreezer_tree
ok 3 test_cgfreezer_forkbomb
Cgroup /sys/fs/cgroup/cg_test_mkdir_A/cg_test_mkdir_B isn't frozen
not ok 4 test_cgfreezer_mkdir
ok 5 test_cgfreezer_rmdir
ok 6 test_cgfreezer_migrate
ok 7 test_cgfreezer_ptrace
ok 8 test_cgfreezer_stopped
ok 9 test_cgfreezer_ptraced
ok 10 test_cgfreezer_vfork
And with this patch:
~/test_freezer
ok 1 test_cgfreezer_simple
ok 2 test_cgfreezer_tree
ok 3 test_cgfreezer_forkbomb
ok 4 test_cgfreezer_mkdir
ok 5 test_cgfreezer_rmdir
ok 6 test_cgfreezer_migrate
ok 7 test_cgfreezer_ptrace
ok 8 test_cgfreezer_stopped
ok 9 test_cgfreezer_ptraced
ok 10 test_cgfreezer_vfork
Reported-by: Mark Crossen <mcrossen@fb.com>
Signed-off-by: Roman Gushchin <guro@fb.com>
Fixes: 76f969e894 ("cgroup: cgroup v2 freezer")
Cc: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Tejun Heo <tj@kernel.org>
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Merge tag 'for-linus-20190912' of gitolite.kernel.org:pub/scm/linux/kernel/git/brauner/linux
Pull clone3 fix from Christian Brauner:
"This is a last-minute bugfix for clone3() that should go in before we
release 5.3 with clone3().
clone3() did not verify that the exit_signal argument was set to a
valid signal. This can be used to cause a crash by specifying a signal
greater than NSIG. e.g. -1.
The commit from Eugene adds a check to copy_clone_args_from_user() to
verify that the exit signal is limited by CSIGNAL as with legacy
clone() and that the signal is valid. With this we don't get the
legacy clone behavior were an invalid signal could be handed down and
would only be detected and then ignored in do_notify_parent(). Users
of clone3() will now get a proper error right when they pass an
invalid exit signal. Note, that this is not a change in user-visible
behavior since no kernel with clone3() has been released yet"
* tag 'for-linus-20190912' of gitolite.kernel.org:pub/scm/linux/kernel/git/brauner/linux:
fork: block invalid exit signals with clone3()
Previously, higher 32 bits of exit_signal fields were lost when copied
to the kernel args structure (that uses int as a type for the respective
field). Moreover, as Oleg has noted, exit_signal is used unchecked, so
it has to be checked for sanity before use; for the legacy syscalls,
applying CSIGNAL mask guarantees that it is at least non-negative;
however, there's no such thing is done in clone3() code path, and that
can break at least thread_group_leader.
This commit adds a check to copy_clone_args_from_user() to verify that
the exit signal is limited by CSIGNAL as with legacy clone() and that
the signal is valid. With this we don't get the legacy clone behavior
were an invalid signal could be handed down and would only be detected
and ignored in do_notify_parent(). Users of clone3() will now get a
proper error when they pass an invalid exit signal. Note, that this is
not user-visible behavior since no kernel with clone3() has been
released yet.
The following program will cause a splat on a non-fixed clone3() version
and will fail correctly on a fixed version:
#define _GNU_SOURCE
#include <linux/sched.h>
#include <linux/types.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/syscall.h>
#include <sys/wait.h>
#include <unistd.h>
int main(int argc, char *argv[])
{
pid_t pid = -1;
struct clone_args args = {0};
args.exit_signal = -1;
pid = syscall(__NR_clone3, &args, sizeof(struct clone_args));
if (pid < 0)
exit(EXIT_FAILURE);
if (pid == 0)
exit(EXIT_SUCCESS);
wait(NULL);
exit(EXIT_SUCCESS);
}
Fixes: 7f192e3cd3 ("fork: add clone3")
Reported-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Link: https://lore.kernel.org/r/4b38fa4ce420b119a4c6345f42fe3cec2de9b0b5.1568223594.git.esyr@redhat.com
[christian.brauner@ubuntu.com: simplify check and rework commit message]
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Pull perf fix from Ingo Molnar:
"Fix an initialization bug in the hw-breakpoints, which triggered on
the ARM platform"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/hw_breakpoint: Fix arch_hw_breakpoint use-before-initialization
Pull irq fix from Ingo Molnar:
"Fix a race in the IRQ resend mechanism, which can result in a NULL
dereference crash"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Prevent NULL pointer dereference in resend_irqs()
You can pass opaque pointers directly.
I also renamed 'va' and 'vb' into more meaningful arguments.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Commit 8651ec01da ("module: add support for symbol namespaces.")
broke linking for arm64 defconfig:
| lib/crypto/arc4.o: In function `__ksymtab_arc4_setkey':
| arc4.c:(___ksymtab+arc4_setkey+0x8): undefined reference to `no symbol'
| lib/crypto/arc4.o: In function `__ksymtab_arc4_crypt':
| arc4.c:(___ksymtab+arc4_crypt+0x8): undefined reference to `no symbol'
This is because the dummy initialisation of the 'namespace_offset' field
in 'struct kernel_symbol' when using EXPORT_SYMBOL on architectures with
support for PREL32 locations uses an offset from an absolute address (0)
in an effort to trick 'offset_to_pointer' into behaving as a NOP,
allowing non-namespaced symbols to be treated in the same way as those
belonging to a namespace.
Unfortunately, place-relative relocations require a symbol reference
rather than an absolute value and, although x86 appears to get away with
this due to placing the kernel text at the top of the address space, it
almost certainly results in a runtime failure if the kernel is relocated
dynamically as a result of KASLR.
Rework 'namespace_offset' so that a value of 0, which cannot occur for a
valid namespaced symbol, indicates that the corresponding symbol does
not belong to a namespace.
Cc: Matthias Maennich <maennich@google.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Fixes: 8651ec01da ("module: add support for symbol namespaces.")
Reported-by: kbuild test robot <lkp@intel.com>
Tested-by: Matthias Maennich <maennich@google.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Matthias Maennich <maennich@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
This splits the size parameter to swiotlb_tbl_map_single() and
swiotlb_tbl_unmap_single() into an alloc_size and a mapping_size
parameter, where the latter one is rounded up to the iommu page
size.
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
It was recently discovered that the linux version of waitid is not a
superset of the other wait functions because it does not include support
for waiting for the current process group. This has two downsides:
1. An extra system call is needed to get the current process group.
2. After the current process group is received and before it is passed
to waitid a signal could arrive causing the current process group to change.
Inherent race-conditions as these make it impossible for userspace to
emulate this functionaly and thus violate async-signal safety
requirements for waitpid.
Arguments can be made for using a different choice of idtype and id
for this case but the BSDs already use this P_PGID and 0 to indicate
waiting for the current process's process group. So be nice to user
space programmers and don't introduce an unnecessary incompatibility.
Some people have noted that the posix description is that
waitpid will wait for the current process group, and that in
the presence of pthreads that process group can change. To get
clarity on this issue I looked at XNU, FreeBSD, and Luminos. All of
those flavors of unix waited for the current process group at the
time of call and as written could not adapt to the process group
changing after the call.
At one point Linux did adapt to the current process group changing but
that stopped in 161550d74c ("pid: sys_wait... fixes"). It has been
over 11 years since Linux has that behavior, no programs that fail
with the change in behavior have been reported, and I could not
find any other unix that does this. So I think it is safe to clarify
the definition of current process group, to current process group
at the time of the wait function.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Alistair Francis <alistair23@gmail.com>
Cc: Zong Li <zongbox@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: GNU C Library <libc-alpha@sourceware.org>
Link: https://lore.kernel.org/r/20190814154400.6371-2-christian.brauner@ubuntu.com
The recent consolidation of the three permission checks introduced a subtle
regression. For timer_create() with a process wide timer it returns the
current task if the lookup through the PID which is encoded into the
clockid results in returning current.
That's broken because it does not validate whether the current task is the
group leader.
That was caused by the two different variants of permission checks:
- posix_cpu_timer_get() allowed access to the process wide clock when the
looked up task is current. That's not an issue because the process wide
clock is in the shared sighand.
- posix_cpu_timer_create() made sure that the looked up task is the group
leader.
Restore the previous state.
Note, that these permission checks are more than questionable, but that's
subject to follow up changes.
Fixes: 6ae40e3fdc ("posix-cpu-timers: Provide task validation functions")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1909052314110.1902@nanos.tec.linutronix.de
If MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS is enabled (default=n), the
requirement for modules to import all namespaces that are used by
the module is relaxed.
Enabling this option effectively allows (invalid) modules to be loaded
while only a warning is emitted.
Disabling this option keeps the enforcement at module loading time and
loading is denied if the module's imports are not satisfactory.
Reviewed-by: Martijn Coenen <maco@android.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
The EXPORT_SYMBOL_NS() and EXPORT_SYMBOL_NS_GPL() macros can be used to
export a symbol to a specific namespace. There are no _GPL_FUTURE and
_UNUSED variants because these are currently unused, and I'm not sure
they are necessary.
I didn't add EXPORT_SYMBOL_NS() for ASM exports; this patch sets the
namespace of ASM exports to NULL by default. In case of relative
references, it will be relocatable to NULL. If there's a need, this
should be pretty easy to add.
A module that wants to use a symbol exported to a namespace must add a
MODULE_IMPORT_NS() statement to their module code; otherwise, modpost
will complain when building the module, and the kernel module loader
will emit an error and fail when loading the module.
MODULE_IMPORT_NS() adds a modinfo tag 'import_ns' to the module. That
tag can be observed by the modinfo command, modpost and kernel/module.c
at the time of loading the module.
The ELF symbols are renamed to include the namespace with an asm label;
for example, symbol 'usb_stor_suspend' in namespace USB_STORAGE becomes
'usb_stor_suspend.USB_STORAGE'. This allows modpost to do namespace
checking, without having to go through all the effort of parsing ELF and
relocation records just to get to the struct kernel_symbols.
On x86_64 I saw no difference in binary size (compression), but at
runtime this will require a word of memory per export to hold the
namespace. An alternative could be to store namespaced symbols in their
own section and use a separate 'struct namespaced_kernel_symbol' for
that section, at the cost of making the module loader more complex.
Co-developed-by: Martijn Coenen <maco@android.com>
Signed-off-by: Martijn Coenen <maco@android.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Similar to modpost's get_next_modinfo(), introduce get_next_modinfo() in
kernel/module.c to acquire any further values associated with the same
modinfo tag name. That is useful for any tags that have multiple
occurrences (such as 'alias'), but is in particular introduced here as
part of the symbol namespaces patch series to read the (potentially)
multiple namespaces a module is importing.
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Martijn Coenen <maco@android.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
In some special cases we must not block, but there's not a spinlock,
preempt-off, irqs-off or similar critical section already that arms the
might_sleep() debug checks. Add a non_block_start/end() pair to annotate
these.
This will be used in the oom paths of mmu-notifiers, where blocking is not
allowed to make sure there's forward progress. Quoting Michal:
"The notifier is called from quite a restricted context - oom_reaper -
which shouldn't depend on any locks or sleepable conditionals. The code
should be swift as well but we mostly do care about it to make a forward
progress. Checking for sleepable context is the best thing we could come
up with that would describe these demands at least partially."
Peter also asked whether we want to catch spinlocks on top, but Michal
said those are less of a problem because spinlocks can't have an indirect
dependency upon the page allocator and hence close the loop with the oom
reaper.
Suggested by Michal Hocko.
Link: https://lore.kernel.org/r/20190826201425.17547-4-daniel.vetter@ffwll.ch
Acked-by: Christian König <christian.koenig@amd.com> (v1)
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The powerpc version only supported 64 bit. Add some
code to switch decoding of fields during runtime so
we can kexec a 32 bit kernel from a 64 bit kernel and
vice versa.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Helge Deller <deller@gmx.de>
base was never assigned, so we can remove it.
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
It wasn't used anywhere, so lets drop it.
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
It's not used anywhere so just drop it.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Helge Deller <deller@gmx.de>
We're not using them, so we can drop the parsing.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Change the order to have a 64/32/16 order, no functional change.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Right now powerpc provides an implementation to read elf files
with the kexec_file_load() syscall. Make that available as a public
kexec interface so it can be re-used on other architectures.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Daniel Borkmann says:
====================
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Add the ability to use unaligned chunks in the AF_XDP umem. By
relaxing where the chunks can be placed, it allows to use an
arbitrary buffer size and place whenever there is a free
address in the umem. Helps more seamless DPDK AF_XDP driver
integration. Support for i40e, ixgbe and mlx5e, from Kevin and
Maxim.
2) Addition of a wakeup flag for AF_XDP tx and fill rings so the
application can wake up the kernel for rx/tx processing which
avoids busy-spinning of the latter, useful when app and driver
is located on the same core. Support for i40e, ixgbe and mlx5e,
from Magnus and Maxim.
3) bpftool fixes for printf()-like functions so compiler can actually
enforce checks, bpftool build system improvements for custom output
directories, and addition of 'bpftool map freeze' command, from Quentin.
4) Support attaching/detaching XDP programs from 'bpftool net' command,
from Daniel.
5) Automatic xskmap cleanup when AF_XDP socket is released, and several
barrier/{read,write}_once fixes in AF_XDP code, from Björn.
6) Relicense of bpf_helpers.h/bpf_endian.h for future libbpf
inclusion as well as libbpf versioning improvements, from Andrii.
7) Several new BPF kselftests for verifier precision tracking, from Alexei.
8) Several BPF kselftest fixes wrt endianess to run on s390x, from Ilya.
9) And more BPF kselftest improvements all over the place, from Stanislav.
10) Add simple BPF map op cache for nfp driver to batch dumps, from Jakub.
11) AF_XDP socket umem mapping improvements for 32bit archs, from Ivan.
12) Add BPF-to-BPF call and BTF line info support for s390x JIT, from Yauheni.
13) Small optimization in arm64 JIT to spare 1 insns for BPF_MOD, from Jerin.
14) Fix an error check in bpf_tcp_gen_syncookie() helper, from Petar.
15) Various minor fixes and cleanups, from Nathan, Masahiro, Masanari,
Peter, Wei, Yue.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
- Large GICv3 updates to support new PPI and SPI ranges
- Conver all alloc_fwnode() users to use PAs instead of VAs
- Add support for Marvell's MMP3 irqchip
- Add support for Amlogic Meson SM1
- Various cleanups and fixes
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Merge tag 'irqchip-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core
Pull irqchip updates for Linux 5.4 from Marc Zyngier:
- Large GICv3 updates to support new PPI and SPI ranges
- Conver all alloc_fwnode() users to use PAs instead of VAs
- Add support for Marvell's MMP3 irqchip
- Add support for Amlogic Meson SM1
- Various cleanups and fixes
If we disable the compiler's auto-initialization feature, if
-fplugin-arg-structleak_plugin-byref or -ftrivial-auto-var-init=pattern
are disabled, arch_hw_breakpoint may be used before initialization after:
9a4903dde2 ("perf/hw_breakpoint: Split attribute parse and commit")
On our ARM platform, the struct step_ctrl in arch_hw_breakpoint, which
used to be zero-initialized by kzalloc(), may be used in
arch_install_hw_breakpoint() without initialization.
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alix Wu <alix.wu@mediatek.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: YJ Chiang <yj.chiang@mediatek.com>
Link: https://lkml.kernel.org/r/20190906060115.9460-1-mark-pk.tsai@mediatek.com
[ Minor edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The following crash was observed:
Unable to handle kernel NULL pointer dereference at 0000000000000158
Internal error: Oops: 96000004 [#1] SMP
pc : resend_irqs+0x68/0xb0
lr : resend_irqs+0x64/0xb0
...
Call trace:
resend_irqs+0x68/0xb0
tasklet_action_common.isra.6+0x84/0x138
tasklet_action+0x2c/0x38
__do_softirq+0x120/0x324
run_ksoftirqd+0x44/0x60
smpboot_thread_fn+0x1ac/0x1e8
kthread+0x134/0x138
ret_from_fork+0x10/0x18
The reason for this is that the interrupt resend mechanism happens in soft
interrupt context, which is a asynchronous mechanism versus other
operations on interrupts. free_irq() does not take resend handling into
account. Thus, the irq descriptor might be already freed before the resend
tasklet is executed. resend_irqs() does not check the return value of the
interrupt descriptor lookup and derefences the return value
unconditionally.
1):
__setup_irq
irq_startup
check_irq_resend // activate softirq to handle resend irq
2):
irq_domain_free_irqs
irq_free_descs
free_desc
call_rcu(&desc->rcu, delayed_free_desc)
3):
__do_softirq
tasklet_action
resend_irqs
desc = irq_to_desc(irq)
desc->handle_irq(desc) // desc is NULL --> Ooops
Fix this by adding a NULL pointer check in resend_irqs() before derefencing
the irq descriptor.
Fixes: a4633adcdb ("[PATCH] genirq: add genirq sw IRQ-retrigger")
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1630ae13-5c8e-901e-de09-e740b6a426a7@huawei.com
ENOTSUPP is not supposed to be returned to userspace. This was found on an
OpenPower machine, where the RTC does not support set_alarm.
On that system, a clock_nanosleep(CLOCK_REALTIME_ALARM, ...) results in
"524 Unknown error 524"
Replace it with EOPNOTSUPP which results in the expected "95 Operation not
supported" error.
Fixes: 1c6b39ad3f (alarmtimers: Return -ENOTSUPP if no RTC device is present)
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190903171802.28314-1-cascardo@canonical.com
Add "gfp_t" support in synthetic_events, then the "gfp_t" type
parameter in some functions can be traced.
Prints the gfp flags as hex in addition to the human-readable flag
string. Example output:
whoopsie-630 [000] ...1 78.969452: testevent: bar=b20 (GFP_ATOMIC|__GFP_ZERO)
rcuc/0-11 [000] ...1 81.097555: testevent: bar=a20 (GFP_ATOMIC)
rcuc/0-11 [000] ...1 81.583123: testevent: bar=a20 (GFP_ATOMIC)
Link: http://lkml.kernel.org/r/20190712015308.9908-1-zhengjun.xing@linux.intel.com
Signed-off-by: Zhengjun Xing <zhengjun.xing@linux.intel.com>
[ Added printing of flag names ]
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The problem can be seen in the following two tests:
0: (bf) r3 = r10
1: (55) if r3 != 0x7b goto pc+0
2: (7a) *(u64 *)(r3 -8) = 0
3: (79) r4 = *(u64 *)(r10 -8)
..
0: (85) call bpf_get_prandom_u32#7
1: (bf) r3 = r10
2: (55) if r3 != 0x7b goto pc+0
3: (7b) *(u64 *)(r3 -8) = r0
4: (79) r4 = *(u64 *)(r10 -8)
When backtracking need to mark R4 it will mark slot fp-8.
But ST or STX into fp-8 could belong to the same block of instructions.
When backtracing is done the parent state may have fp-8 slot
as "unallocated stack". Which will cause verifier to warn
and incorrectly reject such programs.
Writes into stack via non-R10 register are rare. llvm always
generates canonical stack spill/fill.
For such pathological case fall back to conservative precision
tracking instead of rejecting.
Reported-by: syzbot+c8d66267fd2b5955287e@syzkaller.appspotmail.com
Fixes: b5dc0163d8 ("bpf: precise scalar_value tracking")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The recent change to avoid taking the expiry lock when a timer is currently
migrated missed to add a bracket at the end of the if statement leading to
compile errors. Since that commit the variable `migration_base' is always
used but it is only available on SMP configuration thus leading to another
compile error. The changelog says "The timer base and base->cpu_base
cannot be NULL in the code path", so it is safe to limit this check to SMP
configurations only.
Add the missing bracket to the if statement and hide `migration_base'
behind CONFIG_SMP bars.
[ tglx: Mark the functions inline ... ]
Fixes: 68b2c8c1e4 ("hrtimer: Don't take expiry_lock when timer is currently migrated")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190904145527.eah7z56ntwobqm6j@linutronix.de
Since BUG() and WARN() may use a trap (e.g. UD2 on x86) to
get the address where the BUG() has occurred, kprobes can not
do single-step out-of-line that instruction. So prohibit
probing on such address.
Without this fix, if someone put a kprobe on WARN(), the
kernel will crash with invalid opcode error instead of
outputing warning message, because kernel can not find
correct bug address.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S . Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naveen N . Rao <naveen.n.rao@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/156750890133.19112.3393666300746167111.stgit@devnote2
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Thadeu Lima de Souza Cascardo reported that 'chrt' broke on recent kernels:
$ chrt -p $$
chrt: failed to get pid 26306's policy: Argument list too long
and he has root-caused the bug to the following commit increasing sched_attr
size and breaking sched_read_attr() into returning -EFBIG:
a509a7cd79 ("sched/uclamp: Extend sched_setattr() to support utilization clamping")
The other, bigger bug is that the whole sched_getattr() and sched_read_attr()
logic of checking non-zero bits in new ABI components is arguably broken,
and pretty much any extension of the ABI will spuriously break the ABI.
That's way too fragile.
Instead implement the perf syscall's extensible ABI instead, which we
already implement on the sched_setattr() side:
- if user-attributes have the same size as kernel attributes then the
logic is unchanged.
- if user-attributes are larger than the kernel knows about then simply
skip the extra bits, but set attr->size to the (smaller) kernel size
so that tooling can (in principle) handle older kernel as well.
- if user-attributes are smaller than the kernel knows about then just
copy whatever user-space can accept.
Also clean up the whole logic:
- Simplify the code flow - there's no need for 'ret' for example.
- Standardize on 'kattr/uattr' and 'ksize/usize' naming to make sure we
always know which side we are dealing with.
- Why is it called 'read' when what it does is to copy to user? This
code is so far away from VFS read() semantics that the naming is
actively confusing. Name it sched_attr_copy_to_user() instead, which
mirrors other copy_to_user() functionality.
- Move the attr->size assignment from the head of sched_getattr() to the
sched_attr_copy_to_user() function. Nothing else within the kernel
should care about the size of the structure.
With these fixes the sched_getattr() syscall now nicely supports an
extensible ABI in both a forward and backward compatible fashion, and
will also fix the chrt bug.
As an added bonus the bogus -EFBIG return is removed as well, which as
Thadeu noted should have been -E2BIG to begin with.
Reported-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Patrick Bellasi <patrick.bellasi@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: a509a7cd79 ("sched/uclamp: Extend sched_setattr() to support utilization clamping")
Link: https://lkml.kernel.org/r/20190904075532.GA26751@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
CONFIG_SHELL falls back to sh when bash is not installed on the system,
but nobody is testing such a case since bash is usually installed.
So, shell scripts invoked by CONFIG_SHELL are only tested with bash.
It makes it difficult to test whether the hashbang #!/bin/sh is real.
For example, #!/bin/sh in arch/powerpc/kernel/prom_init_check.sh is
false. (I fixed it up)
Besides, some shell scripts invoked by CONFIG_SHELL use bash-extension
and #!/bin/bash is specified as the hashbang, while CONFIG_SHELL may
not always be set to bash.
Probably, the right thing to do is to introduce BASH, which is bash by
default, and always set CONFIG_SHELL to sh. Replace $(CONFIG_SHELL)
with $(BASH) for bash scripts.
If somebody tries to add bash-extension to a #!/bin/sh script, it will
be caught in testing because /bin/sh is a symlink to dash on some major
distributions.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
A helper to find the backing page array based on a virtual address.
This also ensures we do the same vm_flags check everywhere instead
of slightly different or missing ones in a few places.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Currently the generic dma remap allocator gets a vm_flags passed by
the caller that is a little confusing. We just introduced a generic
vmalloc-level flag to identify the dma coherent allocations, so use
that everywhere and remove the now pointless argument.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Most dma_map_ops instances are IOMMUs that work perfectly fine in 32-bits
of IOVA space, and the generic direct mapping code already provides its
own routines that is intelligent based on the amount of memory actually
present. Wire up the dma-direct routine for the ARM direct mapping code
as well, and otherwise default to the constant 32-bit mask. This way
we only need to override it for the occasional odd IOMMU that requires
64-bit IOVA support, or IOMMU drivers that are more efficient if they
can fall back to the direct mapping.
Signed-off-by: Christoph Hellwig <hch@lst.de>
dma_declare_coherent_memory is something that the platform setup code
(which pretty much means the device tree these days) need to do so that
drivers can use the memory as declared by the platform. Drivers
themselves have no business calling this function.
Signed-off-by: Christoph Hellwig <hch@lst.de>
This function is entirely unused given that declared memory is
generally provided by platform setup code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
CONFIG_ARCH_NO_COHERENT_DMA_MMAP is now functionally identical to
!CONFIG_MMU, so remove the separate symbol. The only difference is that
arm did not set it for !CONFIG_MMU, but arm uses a separate dma mapping
implementation including its own mmap method, which is handled by moving
the CONFIG_MMU check in dma_can_mmap so that is only applies to the
dma-direct case, just as the other ifdefs for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Add a helper to check if DMA allocations for a specific device can be
mapped to userspace using dma_mmap_*.
Signed-off-by: Christoph Hellwig <hch@lst.de>
While the default ->mmap and ->get_sgtable implementations work for the
majority of our dma_map_ops impementations they are inherently safe
for others that don't use the page allocator or CMA and/or use their
own way of remapping not covered by the common code. So remove the
defaults if these methods are not wired up, but instead wire up the
default implementations for all safe instances.
Fixes: e1c7e32453 ("dma-mapping: always provide the dma_map_ops based implementation")
Signed-off-by: Christoph Hellwig <hch@lst.de>
The comment that says that module_event() is not static is clearly
wrong.
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
strncmp(str, const, len) is error-prone.
We had better use newly introduced
str_has_prefix() instead of it.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
The play_idle resolution is 1ms. The intel_powerclamp bases the idle
duration on jiffies. The idle injection API is also using msec based
duration but has no user yet.
Unfortunately, msec based time does not fit well when we want to
inject idle cycle precisely with shallow idle state.
In order to set the scene for the incoming idle injection user, move
the precision up to usec when calling play_idle.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Recently device pass-through stops working for Linux VM running on Hyper-V.
git-bisect shows the regression is caused by the recent commit
467a3bb974 ("PCI: hv: Allocate a named fwnode ..."), but the root cause
is that the commit d59f6617ee forgets to set the domain->fwnode for
IRQCHIP_FWNODE_NAMED*, and as a result:
1. The domain->fwnode remains to be NULL.
2. irq_find_matching_fwspec() returns NULL since "h->fwnode == fwnode" is
false, and pci_set_bus_msi_domain() sets the Hyper-V PCI root bus's
msi_domain to NULL.
3. When the device is added onto the root bus, the device's dev->msi_domain
is set to NULL in pci_set_msi_domain().
4. When a device driver tries to enable MSI-X, pci_msi_setup_msi_irqs()
calls arch_setup_msi_irqs(), which uses the native MSI chip (i.e.
arch/x86/kernel/apic/msi.c: pci_msi_controller) to set up the irqs, but
actually pci_msi_setup_msi_irqs() is supposed to call
msi_domain_alloc_irqs() with the hbus->irq_domain, which is created in
hv_pcie_init_irq_domain() and is associated with the Hyper-V chip
hv_msi_irq_chip. Consequently, the irq line is not properly set up, and
the device driver can not receive any interrupt.
Fixes: d59f6617ee ("genirq: Allow fwnode to carry name information only")
Fixes: 467a3bb974 ("PCI: hv: Allocate a named fwnode instead of an address-based one")
Reported-by: Lili Deng <v-lide@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/PU1P153MB01694D9AF625AC335C600C5FBFBE0@PU1P153MB0169.APCP153.PROD.OUTLOOK.COM
The supported clamp indexes are defined in 'enum clamp_id', however, because
of the code logic in some of the first utilization clamping series version,
sometimes we needed to use 'unsigned int' to represent indices.
This is not more required since the final version of the uclamp_* APIs can
always use the proper enum uclamp_id type.
Fix it with a bulk rename now that we have all the bits merged.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Michal Koutny <mkoutny@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190822132811.31294-7-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On updates of task group (TG) clamp values, ensure that these new values
are enforced on all RUNNABLE tasks of the task group, i.e. all RUNNABLE
tasks are immediately boosted and/or capped as requested.
Do that each time we update effective clamps from cpu_util_update_eff().
Use the *cgroup_subsys_state (css) to walk the list of tasks in each
affected TG and update their RUNNABLE tasks.
Update each task by using the same mechanism used for cpu affinity masks
updates, i.e. by taking the rq lock.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Michal Koutny <mkoutny@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190822132811.31294-6-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When a task specific clamp value is configured via sched_setattr(2), this
value is accounted in the corresponding clamp bucket every time the task is
{en,de}qeued. However, when cgroups are also in use, the task specific
clamp values could be restricted by the task_group (TG) clamp values.
Update uclamp_cpu_inc() to aggregate task and TG clamp values. Every time a
task is enqueued, it's accounted in the clamp bucket tracking the smaller
clamp between the task specific value and its TG effective value. This
allows to:
1. ensure cgroup clamps are always used to restrict task specific requests,
i.e. boosted not more than its TG effective protection and capped at
least as its TG effective limit.
2. implement a "nice-like" policy, where tasks are still allowed to request
less than what enforced by their TG effective limits and protections
Do this by exploiting the concept of "effective" clamp, which is already
used by a TG to track parent enforced restrictions.
Apply task group clamp restrictions only to tasks belonging to a child
group. While, for tasks in the root group or in an autogroup, system
defaults are still enforced.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Michal Koutny <mkoutny@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190822132811.31294-5-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The clamp values are not tunable at the level of the root task group.
That's for two main reasons:
- the root group represents "system resources" which are always
entirely available from the cgroup standpoint.
- when tuning/restricting "system resources" makes sense, tuning must
be done using a system wide API which should also be available when
control groups are not.
When a system wide restriction is available, cgroups should be aware of
its value in order to know exactly how much "system resources" are
available for the subgroups.
Utilization clamping supports already the concepts of:
- system defaults: which define the maximum possible clamp values
usable by tasks.
- effective clamps: which allows a parent cgroup to constraint (maybe
temporarily) its descendants without losing the information related
to the values "requested" from them.
Exploit these two concepts and bind them together in such a way that,
whenever system default are tuned, the new values are propagated to
(possibly) restrict or relax the "effective" value of nested cgroups.
When cgroups are in use, force an update of all the RUNNABLE tasks.
Otherwise, keep things simple and do just a lazy update next time each
task will be enqueued.
Do that since we assume a more strict resource control is required when
cgroups are in use. This allows also to keep "effective" clamp values
updated in case we need to expose them to user-space.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Michal Koutny <mkoutny@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190822132811.31294-4-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In order to properly support hierarchical resources control, the cgroup
delegation model requires that attribute writes from a child group never
fail but still are locally consistent and constrained based on parent's
assigned resources. This requires to properly propagate and aggregate
parent attributes down to its descendants.
Implement this mechanism by adding a new "effective" clamp value for each
task group. The effective clamp value is defined as the smaller value
between the clamp value of a group and the effective clamp value of its
parent. This is the actual clamp value enforced on tasks in a task group.
Since it's possible for a cpu.uclamp.min value to be bigger than the
cpu.uclamp.max value, ensure local consistency by restricting each
"protection" (i.e. min utilization) with the corresponding "limit"
(i.e. max utilization).
Do that at effective clamps propagation to ensure all user-space write
never fails while still always tracking the most restrictive values.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Michal Koutny <mkoutny@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190822132811.31294-3-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The cgroup CPU bandwidth controller allows to assign a specified
(maximum) bandwidth to the tasks of a group. However this bandwidth is
defined and enforced only on a temporal base, without considering the
actual frequency a CPU is running on. Thus, the amount of computation
completed by a task within an allocated bandwidth can be very different
depending on the actual frequency the CPU is running that task.
The amount of computation can be affected also by the specific CPU a
task is running on, especially when running on asymmetric capacity
systems like Arm's big.LITTLE.
With the availability of schedutil, the scheduler is now able
to drive frequency selections based on actual task utilization.
Moreover, the utilization clamping support provides a mechanism to
bias the frequency selection operated by schedutil depending on
constraints assigned to the tasks currently RUNNABLE on a CPU.
Giving the mechanisms described above, it is now possible to extend the
cpu controller to specify the minimum (or maximum) utilization which
should be considered for tasks RUNNABLE on a cpu.
This makes it possible to better defined the actual computational
power assigned to task groups, thus improving the cgroup CPU bandwidth
controller which is currently based just on time constraints.
Extend the CPU controller with a couple of new attributes uclamp.{min,max}
which allow to enforce utilization boosting and capping for all the
tasks in a group.
Specifically:
- uclamp.min: defines the minimum utilization which should be considered
i.e. the RUNNABLE tasks of this group will run at least at a
minimum frequency which corresponds to the uclamp.min
utilization
- uclamp.max: defines the maximum utilization which should be considered
i.e. the RUNNABLE tasks of this group will run up to a
maximum frequency which corresponds to the uclamp.max
utilization
These attributes:
a) are available only for non-root nodes, both on default and legacy
hierarchies, while system wide clamps are defined by a generic
interface which does not depends on cgroups. This system wide
interface enforces constraints on tasks in the root node.
b) enforce effective constraints at each level of the hierarchy which
are a restriction of the group requests considering its parent's
effective constraints. Root group effective constraints are defined
by the system wide interface.
This mechanism allows each (non-root) level of the hierarchy to:
- request whatever clamp values it would like to get
- effectively get only up to the maximum amount allowed by its parent
c) have higher priority than task-specific clamps, defined via
sched_setattr(), thus allowing to control and restrict task requests.
Add two new attributes to the cpu controller to collect "requested"
clamp values. Allow that at each non-root level of the hierarchy.
Keep it simple by not caring now about "effective" values computation
and propagation along the hierarchy.
Update sysctl_sched_uclamp_handler() to use the newly introduced
uclamp_mutex so that we serialize system default updates with cgroup
relate updates.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Michal Koutny <mkoutny@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Alessio Balsini <balsini@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Perret <quentin.perret@arm.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lkml.kernel.org/r/20190822132811.31294-2-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
SD_BALANCE_{FORK,EXEC} and SD_WAKE_AFFINE are stripped in sd_init()
for any sched domains with a NUMA distance greater than 2 hops
(RECLAIM_DISTANCE). The idea being that it's expensive to balance
across domains that far apart.
However, as is rather unfortunately explained in:
commit 32e45ff43e ("mm: increase RECLAIM_DISTANCE to 30")
the value for RECLAIM_DISTANCE is based on node distance tables from
2011-era hardware.
Current AMD EPYC machines have the following NUMA node distances:
node distances:
node 0 1 2 3 4 5 6 7
0: 10 16 16 16 32 32 32 32
1: 16 10 16 16 32 32 32 32
2: 16 16 10 16 32 32 32 32
3: 16 16 16 10 32 32 32 32
4: 32 32 32 32 10 16 16 16
5: 32 32 32 32 16 10 16 16
6: 32 32 32 32 16 16 10 16
7: 32 32 32 32 16 16 16 10
where 2 hops is 32.
The result is that the scheduler fails to load balance properly across
NUMA nodes on different sockets -- 2 hops apart.
For example, pinning 16 busy threads to NUMA nodes 0 (CPUs 0-7) and 4
(CPUs 32-39) like so,
$ numactl -C 0-7,32-39 ./spinner 16
causes all threads to fork and remain on node 0 until the active
balancer kicks in after a few seconds and forcibly moves some threads
to node 4.
Override node_reclaim_distance for AMD Zen.
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Suravee.Suthikulpanit@amd.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas.Lendacky@amd.com
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20190808195301.13222-3-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
do_sched_cfs_period_timer() will refill cfs_b runtime and call
distribute_cfs_runtime to unthrottle cfs_rq, sometimes cfs_b->runtime
will allocate all quota to one cfs_rq incorrectly, then other cfs_rqs
attached to this cfs_b can't get runtime and will be throttled.
We find that one throttled cfs_rq has non-negative
cfs_rq->runtime_remaining and cause an unexpetced cast from s64 to u64
in snippet:
distribute_cfs_runtime() {
runtime = -cfs_rq->runtime_remaining + 1;
}
The runtime here will change to a large number and consume all
cfs_b->runtime in this cfs_b period.
According to Ben Segall, the throttled cfs_rq can have
account_cfs_rq_runtime called on it because it is throttled before
idle_balance, and the idle_balance calls update_rq_clock to add time
that is accounted to the task.
This commit prevents cfs_rq to be assgined new runtime if it has been
throttled until that distribute_cfs_runtime is called.
Signed-off-by: Liangyan <liangyan.peng@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: shanpeic@linux.alibaba.com
Cc: stable@vger.kernel.org
Cc: xlpang@linux.alibaba.com
Fixes: d3d9dc3302 ("sched: Throttle entities exceeding their allowed bandwidth")
Link: https://lkml.kernel.org/r/20190826121633.6538-1-liangyan.peng@linux.alibaba.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch adds a new DMA API "dma_get_merge_boundary". This function
returns the DMA merge boundary if the DMA layer can merge the segments.
This patch also adds the implementation for a new dma_map_ops pointer.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Pull networking fixes from David Miller:
1) Fix some length checks during OGM processing in batman-adv, from
Sven Eckelmann.
2) Fix regression that caused netfilter conntrack sysctls to not be
per-netns any more. From Florian Westphal.
3) Use after free in netpoll, from Feng Sun.
4) Guard destruction of pfifo_fast per-cpu qdisc stats with
qdisc_is_percpu_stats(), from Davide Caratti. Similar bug is fixed
in pfifo_fast_enqueue().
5) Fix memory leak in mld_del_delrec(), from Eric Dumazet.
6) Handle neigh events on internal ports correctly in nfp, from John
Hurley.
7) Clear SKB timestamp in NF flow table code so that it does not
confuse fq scheduler. From Florian Westphal.
8) taprio destroy can crash if it is invoked in a failure path of
taprio_init(), because the list head isn't setup properly yet and
the list del is unconditional. Perform the list add earlier to
address this. From Vladimir Oltean.
9) Make sure to reapply vlan filters on device up, in aquantia driver.
From Dmitry Bogdanov.
10) sgiseeq driver releases DMA memory using free_page() instead of
dma_free_attrs(). From Christophe JAILLET.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (58 commits)
net: seeq: Fix the function used to release some memory in an error handling path
enetc: Add missing call to 'pci_free_irq_vectors()' in probe and remove functions
net: bcmgenet: use ethtool_op_get_ts_info()
tc-testing: don't hardcode 'ip' in nsPlugin.py
net: dsa: microchip: add KSZ8563 compatibility string
dt-bindings: net: dsa: document additional Microchip KSZ8563 switch
net: aquantia: fix out of memory condition on rx side
net: aquantia: linkstate irq should be oneshot
net: aquantia: reapply vlan filters on up
net: aquantia: fix limit of vlan filters
net: aquantia: fix removal of vlan 0
net/sched: cbs: Set default link speed to 10 Mbps in cbs_set_port_rate
taprio: Set default link speed to 10 Mbps in taprio_set_picos_per_byte
taprio: Fix kernel panic in taprio_destroy
net: dsa: microchip: fill regmap_config name
rxrpc: Fix lack of conn cleanup when local endpoint is cleaned up [ver #2]
net: stmmac: dwmac-rk: Don't fail if phy regulator is absent
amd-xgbe: Fix error path in xgbe_mod_init()
netfilter: nft_meta_bridge: Fix get NFT_META_BRI_IIFVPROTO in network byteorder
mac80211: Correctly set noencrypt for PAE frames
...
The name tracing_reset() was a misnomer, as it really only reset a single
CPU buffer. Rename it to tracing_reset_cpu() and also make it static and
remove the prototype from trace.h, as it is only used in a single function.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As the max stack tracer algorithm is not that easy to understand from the
code, add comments that explain the algorithm and mentions how
ARCH_FTRACE_SHIFT_STACK_TRACER affects it.
Link: http://lkml.kernel.org/r/20190806123455.487ac02b@gandalf.local.home
Suggested-by: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Most archs (well at least x86) store the function call return address on the
stack before storing the local variables for the function. The max stack
tracer depends on this in its algorithm to display the stack size of each
function it finds in the back trace.
Some archs (arm64), may store the return address (from its link register)
just before calling a nested function. There's no reason to save the link
register on leaf functions, as it wont be updated. This breaks the algorithm
of the max stack tracer.
Add a new define ARCH_FTRACE_SHIFT_STACK_TRACER that an architecture may set
if it stores the return address (link register) after it stores the
function's local variables, and have the stack trace shift the values of the
mapped stack size to the appropriate functions.
Link: 20190802094103.163576-1-jiping.ma2@windriver.com
Reported-by: Jiping Ma <jiping.ma2@windriver.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add immediate string parameter (\"string") support to
probe events. This allows you to specify an immediate
(or dummy) parameter instead of fetching a string from
memory.
This feature looks odd, but imagine that you put a probe
on a code to trace some string data. If the code is
compiled into 2 instructions and 1 instruction has a
string on memory but other has no string since it is
optimized out. In that case, you can not fold those into
one event, even if ftrace supported multiple probes on
one event. With this feature, you can set a dummy string
like foo=\"(optimized)":string instead of something
like foo=+0(+0(%bp)):string.
Link: http://lkml.kernel.org/r/156095691687.28024.13372712423865047991.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add immediate value parameter (\1234) support to
probe events. This allows you to specify an immediate
(or dummy) parameter instead of fetching from memory
or register.
This feature looks odd, but imagine when you put a probe
on a code to trace some data. If the code is compiled into
2 instructions and 1 instruction has a value but other has
nothing since it is optimized out.
In that case, you can not fold those into one event, even
if ftrace supported multiple probes on one event.
With this feature, you can set a dummy value like
foo=\deadbeef instead of something like foo=%di.
Link: http://lkml.kernel.org/r/156095690733.28024.13258186548822649469.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add per-probe delete method from one event passing the head of
definition. In other words, the events which match the head
N parameters are deleted.
Link: http://lkml.kernel.org/r/156095689811.28024.221706761151739433.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Allow user to delete a probe from event. This is done by head
match. For example, if we have 2 probes on an event
$ cat kprobe_events
p:kprobes/testprobe _do_fork r1=%ax r2=%dx
p:kprobes/testprobe idle_fork r1=%ax r2=%cx
Then you can remove one of them by passing the head of definition
which identify the probe.
$ echo "-:kprobes/testprobe idle_fork" >> kprobe_events
Link: http://lkml.kernel.org/r/156095688848.28024.15798690082378432435.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Allow user to define several probes on one uprobe event.
Note that this only support appending method. So deleting
event will delete all probes on the event.
Link: http://lkml.kernel.org/r/156095687876.28024.13840331032234992863.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add multi-probe per one event support to kprobe events.
User can define several different probes on one trace event
if those events have same "event signature",
e.g.
# echo p:testevent _do_fork > kprobe_events
# echo p:testevent fork_idle >> kprobe_events
# kprobe_events
p:kprobes/testevent _do_fork
p:kprobes/testevent fork_idle
The event signature is defined by kprobe type (retprobe or not),
the number of args, argument names, and argument types.
Note that this only support appending method. Delete event
operation will delete all probes on the event.
Link: http://lkml.kernel.org/r/156095686913.28024.9357292202316540742.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pass extra arguments to match operation for checking
exact match. If the event doesn't support exact match,
it will be ignored.
Link: http://lkml.kernel.org/r/156095685930.28024.10405547027475590975.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When user gives an event name to delete, delete all
matched events instead of the first one.
This means if there are several events which have same
name but different group (subsystem) name, those are
removed if user passed only the event name, e.g.
# cat kprobe_events
p:group1/testevent _do_fork
p:group2/testevent fork_idle
# echo -:testevent >> kprobe_events
# cat kprobe_events
#
Link: http://lkml.kernel.org/r/156095684958.28024.16597826267117453638.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Split the trace_event related data from trace_probe data structure
and introduce trace_probe_event data structure for its folder.
This trace_probe_event data structure can have multiple trace_probe.
Link: http://lkml.kernel.org/r/156095683995.28024.7552150340561557873.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Allow kprobes which do not modify regs->ip, coexist with livepatch
by dropping FTRACE_OPS_FL_IPMODIFY from ftrace_ops.
User who wants to modify regs->ip (e.g. function fault injection)
must set a dummy post_handler to its kprobes when registering.
However, if such regs->ip modifying kprobes is set on a function,
that function can not be livepatched.
Link: http://lkml.kernel.org/r/156403587671.30117.5233558741694155985.stgit@devnote2
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
- Make exported ftrace function not static
- Fix NULL pointer dereference in reading probes as they are created
- Fix NULL pointer dereference in k/uprobe clean up path
- Various documentation fixes
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Merge tag 'trace-v5.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Small fixes and minor cleanups for tracing:
- Make exported ftrace function not static
- Fix NULL pointer dereference in reading probes as they are created
- Fix NULL pointer dereference in k/uprobe clean up path
- Various documentation fixes"
* tag 'trace-v5.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Correct kdoc formats
ftrace/x86: Remove mcount() declaration
tracing/probe: Fix null pointer dereference
tracing: Make exported ftrace_set_clr_event non-static
ftrace: Check for successful allocation of hash
ftrace: Check for empty hash and comment the race with registering probes
ftrace: Fix NULL pointer dereference in t_probe_next()
Fix the following kdoc warnings:
kernel/trace/trace.c:1579: warning: Function parameter or member 'tr' not described in 'update_max_tr_single'
kernel/trace/trace.c:1579: warning: Function parameter or member 'tsk' not described in 'update_max_tr_single'
kernel/trace/trace.c:1579: warning: Function parameter or member 'cpu' not described in 'update_max_tr_single'
kernel/trace/trace.c:1776: warning: Function parameter or member 'type' not described in 'register_tracer'
kernel/trace/trace.c:2239: warning: Function parameter or member 'task' not described in 'tracing_record_taskinfo'
kernel/trace/trace.c:2239: warning: Function parameter or member 'flags' not described in 'tracing_record_taskinfo'
kernel/trace/trace.c:2269: warning: Function parameter or member 'prev' not described in 'tracing_record_taskinfo_sched_switch'
kernel/trace/trace.c:2269: warning: Function parameter or member 'next' not described in 'tracing_record_taskinfo_sched_switch'
kernel/trace/trace.c:2269: warning: Function parameter or member 'flags' not described in 'tracing_record_taskinfo_sched_switch'
kernel/trace/trace.c:3078: warning: Function parameter or member 'ip' not described in 'trace_vbprintk'
kernel/trace/trace.c:3078: warning: Function parameter or member 'fmt' not described in 'trace_vbprintk'
kernel/trace/trace.c:3078: warning: Function parameter or member 'args' not described in 'trace_vbprintk'
Link: http://lkml.kernel.org/r/20190828052549.2472-2-jakub.kicinski@netronome.com
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The function ftrace_set_clr_event is declared static and marked
EXPORT_SYMBOL_GPL(), which is at best an odd combination. Because the
function was decided to be a part of API, this commit removes the static
attribute and adds the declaration to the header.
Link: http://lkml.kernel.org/r/20190704172110.27041-1-efremov@linux.com
Fixes: f45d1225ad ("tracing: Kernel access to Ftrace instances")
Reviewed-by: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Daniel Borkmann says:
====================
pull-request: bpf 2019-08-31
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) Fix 32-bit zero-extension during constant blinding which
has been causing a regression on ppc64, from Naveen.
2) Fix a latency bug in nfp driver when updating stack index
register, from Jiong.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
In register_ftrace_function_probe(), we are not checking the return
value of alloc_and_copy_ftrace_hash(). The subsequent call to
ftrace_match_records() may end up dereferencing the same. Add a check to
ensure this doesn't happen.
Link: http://lkml.kernel.org/r/26e92574f25ad23e7cafa3cf5f7a819de1832cbe.1562249521.git.naveen.n.rao@linux.vnet.ibm.com
Cc: stable@vger.kernel.org
Fixes: 1ec3a81a0c ("ftrace: Have each function probe use its own ftrace_ops")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The race between adding a function probe and reading the probes that exist
is very subtle. It needs a comment. Also, the issue can also happen if the
probe has has the EMPTY_HASH as its func_hash.
Cc: stable@vger.kernel.org
Fixes: 7b60f3d876 ("ftrace: Dynamically create the probe ftrace_ops for the trace_array")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
LTP testsuite on powerpc results in the below crash:
Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xc00000000029d800
Oops: Kernel access of bad area, sig: 11 [#1]
LE SMP NR_CPUS=2048 NUMA PowerNV
...
CPU: 68 PID: 96584 Comm: cat Kdump: loaded Tainted: G W
NIP: c00000000029d800 LR: c00000000029dac4 CTR: c0000000001e6ad0
REGS: c0002017fae8ba10 TRAP: 0300 Tainted: G W
MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 28022422 XER: 20040000
CFAR: c00000000029d90c DAR: 0000000000000000 DSISR: 40000000 IRQMASK: 0
...
NIP [c00000000029d800] t_probe_next+0x60/0x180
LR [c00000000029dac4] t_mod_start+0x1a4/0x1f0
Call Trace:
[c0002017fae8bc90] [c000000000cdbc40] _cond_resched+0x10/0xb0 (unreliable)
[c0002017fae8bce0] [c0000000002a15b0] t_start+0xf0/0x1c0
[c0002017fae8bd30] [c0000000004ec2b4] seq_read+0x184/0x640
[c0002017fae8bdd0] [c0000000004a57bc] sys_read+0x10c/0x300
[c0002017fae8be30] [c00000000000b388] system_call+0x5c/0x70
The test (ftrace_set_ftrace_filter.sh) is part of ftrace stress tests
and the crash happens when the test does 'cat
$TRACING_PATH/set_ftrace_filter'.
The address points to the second line below, in t_probe_next(), where
filter_hash is dereferenced:
hash = iter->probe->ops.func_hash->filter_hash;
size = 1 << hash->size_bits;
This happens due to a race with register_ftrace_function_probe(). A new
ftrace_func_probe is created and added into the func_probes list in
trace_array under ftrace_lock. However, before initializing the filter,
we drop ftrace_lock, and re-acquire it after acquiring regex_lock. If
another process is trying to read set_ftrace_filter, it will be able to
acquire ftrace_lock during this window and it will end up seeing a NULL
filter_hash.
Fix this by just checking for a NULL filter_hash in t_probe_next(). If
the filter_hash is NULL, then this probe is just being added and we can
simply return from here.
Link: http://lkml.kernel.org/r/05e021f757625cbbb006fad41380323dbe4e3b43.1562249521.git.naveen.n.rao@linux.vnet.ibm.com
Cc: stable@vger.kernel.org
Fixes: 7b60f3d876 ("ftrace: Dynamically create the probe ftrace_ops for the trace_array")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This branch has some cross-arch patches that are a prequisite for the
SVM work. They're in a topic branch in case any of the other arch
maintainers want to merge them to resolve conflicts.
The memory allocated for the atomic pool needs to have the same
mapping attributes that we use for remapping, so use
pgprot_dmacoherent instead of open coding it. Also deduct a
suitable zone to allocate the memory from based on the presence
of the DMA zones.
Signed-off-by: Christoph Hellwig <hch@lst.de>
arch_dma_mmap_pgprot is used for two things:
1) to override the "normal" uncached page attributes for mapping
memory coherent to devices that can't snoop the CPU caches
2) to provide the special DMA_ATTR_WRITE_COMBINE semantics on older
arm systems and some mips platforms
Replace one with the pgprot_dmacoherent macro that is already provided
by arm and much simpler to use, and lift the DMA_ATTR_WRITE_COMBINE
handling to common code with an explicit arch opt-in.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Acked-by: Paul Burton <paul.burton@mips.com> # mips
On architectures that discard .exit.* sections at runtime, a
warning is printed for each jump label that is used within an
in-kernel __exit annotated function:
can't patch jump_label at ehci_hcd_cleanup+0x8/0x3c
WARNING: CPU: 0 PID: 1 at kernel/jump_label.c:410 __jump_label_update+0x12c/0x138
As these functions will never get executed (they are free'd along
with the rest of initmem) - we do not need to patch them and should
not display any warnings.
The warning is displayed because the test required to satisfy
jump_entry_is_init is based on init_section_contains (__init_begin to
__init_end) whereas the test in __jump_label_update is based on
init_kernel_text (_sinittext to _einittext) via kernel_text_address).
Fixes: 1948367768 ("jump_label: Annotate entries that operate on __init code earlier")
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
The state tracking changes broke the expiry active check by not writing to
it and instead sitting timers_active, which is already set.
That's not a big issue as the actual expiry is protected by sighand lock,
so concurrent handling is not possible. That means that the second task
which invokes that function executes the expiry code for nothing.
Write to the proper flag.
Also add a check whether the flag is set into check_process_timers(). That
check had been missing in the code before the rework already. The check for
another task handling the expiry of process wide timers was only done in
the fastpath check. If the fastpath check returns true because a per task
timer expired, then the checking of process wide timers was done in
parallel which is as explained above just a waste of cycles.
Fixes: 244d49e306 ("posix-cpu-timers: Move state tracking to struct posix_cputimers")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <frederic@kernel.org>
- Fix GICv2 emulation bug (KVM)
- Fix deadlock in virtual GIC interrupt injection code (KVM)
- Fix kprobes blacklist init failure due to broken kallsyms lookup
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon:
"Hot on the heels of our last set of fixes are a few more for -rc7.
Two of them are fixing issues with our virtual interrupt controller
implementation in KVM/arm, while the other is a longstanding but
straightforward kallsyms fix which was been acked by Masami and
resolves an initialisation failure in kprobes observed on arm64.
- Fix GICv2 emulation bug (KVM)
- Fix deadlock in virtual GIC interrupt injection code (KVM)
- Fix kprobes blacklist init failure due to broken kallsyms lookup"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
KVM: arm/arm64: vgic-v2: Handle SGI bits in GICD_I{S,C}PENDR0 as WI
KVM: arm/arm64: vgic: Fix potential deadlock when ap_list is long
kallsyms: Don't let kallsyms_lookup_size_offset() fail on retrieving the first symbol
sched_timer must be initialized with the _HARD mode suffix to ensure expiry
in hard interrupt context on RT.
The previous conversion to HARD expiry mode missed on one instance in
tick_nohz_switch_to_nohz(). Fix it up.
Fixes: 902a9f9c50 ("tick: Mark tick related hrtimers to expiry in hard interrupt context")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190823113845.12125-3-bigeasy@linutronix.de
When CONFIG_CPUMASK_OFFSTACK isn't enabled, 'cpumask_var_t' is as
'typedef struct cpumask cpumask_var_t[1]',
so the argument 'node_to_cpumask' alloc_nodes_vectors() can't be declared
as 'const cpumask_var_t *'
Fixes the following warning:
kernel/irq/affinity.c: In function '__irq_build_affinity_masks':
alloc_nodes_vectors(numvecs, node_to_cpumask, cpu_mask,
^
kernel/irq/affinity.c:128:13: note: expected 'const struct cpumask (*)[1]' but argument is of type 'struct cpumask (*)[1]'
static void alloc_nodes_vectors(unsigned int numvecs,
^
Fixes: b1a5a73e64 ("genirq/affinity: Spread vectors on node according to nr_cpu ratio")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190828085815.19931-1-ming.lei@redhat.com
Using a linear O(N) search for timer insertion affects execution time and
D-cache footprint badly with a larger number of timers.
Switch the storage to a timerqueue which is already used for hrtimers and
alarmtimers. It does not affect the size of struct k_itimer as it.alarm is
still larger.
The extra list head for the expiry list will go away later once the expiry
is moved into task work context.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908272129220.1939@nanos.tec.linutronix.de
Both thread and process expiry functions have the same functionality for
sending signals for soft and hard RLIMITs duplicated in 4 different
ways.
Split it out into a common function and cleanup the callsites.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192922.653276779@linutronix.de
The soft RLIMIT expiry code checks whether the soft limit is greater than
the hard limit. That's pointless because if the soft RLIMIT is greater than
the hard RLIMIT then that code cannot be reached as the hard RLIMIT check
is before that and already killed the process.
Remove it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192922.548747613@linutronix.de
Instead of dividing A to match the units of B it's more efficient to
multiply B to match the units of A.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192922.458286860@linutronix.de
With the array based samples and expiry cache, the expiry function can use
a loop to collect timers from the clock specific lists.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192922.365469982@linutronix.de
Deactivation of the expiry cache is done by setting all clock caches to
0. That requires to have a check for zero in all places which update the
expiry cache:
if (cache == 0 || new < cache)
cache = new;
Use U64_MAX as the deactivated value, which allows to remove the zero
checks when updating the cache and reduces it to the obvious check:
if (new < cache)
cache = new;
This also removes the weird workaround in do_prlimit() which was required
to convert a RLIMIT_CPU value of 0 (immediate expiry) to 1 because handing
in 0 to the posix CPU timer code would have effectively disarmed it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192922.275086128@linutronix.de
The comment above the function which arms RLIMIT_CPU in the posix CPU timer
code makes no sense at all. It claims that the kernel does not return an
error code when it rejected the attempt to set RLIMIT_CPU. That's clearly
bogus as the code does an error check and the rlimit is only set and
activated when the permission checks are ok. In case of a rejection an
appropriate error code is returned.
This is a historical and outdated comment which got dragged along even when
the rlimit handling code was rewritten.
Replace it with an explanation why the setup function is not called when
the rlimit value is RLIM_INFINITY and how the 'disarming' is handled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192922.185511287@linutronix.de
The RTIME limit expiry code does not check the hard RTTIME limit for
INFINITY, i.e. being disabled. Add it.
While this could be considered an ABI breakage if something would depend on
this behaviour. Though it's highly unlikely to have an effect because
RLIM_INFINITY is at minimum INT_MAX and the RTTIME limit is in seconds, so
the timer would fire after ~68 years.
Adding this obvious correct limit check also allows further consolidation
of that code and is a prerequisite for cleaning up the 0 based checks and
the rlimit setter code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192922.078293002@linutronix.de
Now that the abused struct task_cputime is gone, it's more natural to
bundle the expiry cache and the list head of each clock into a struct and
have an array of those structs.
Follow the hrtimer naming convention of 'bases' and rename the expiry cache
to 'nextevt' and adapt all usage sites.
Generates also better code .text size shrinks by 80 bytes.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908262021140.1939@nanos.tec.linutronix.de
The last users of the magic struct cputime based expiry cache are
gone. Remove the leftovers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192921.790209622@linutronix.de
The expiry cache is an array indexed by clock ids. The new sample functions
allow to retrieve a corresponding array of samples.
Convert the fastpath expiry checks to make use of the new sample functions
and do the comparisons on the sample and the expiry array.
Make the check for the expiry array being zero array based as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192921.695481430@linutronix.de
Instead of using task_cputime and doing the addition of utime and stime at
all call sites, it's way simpler to have a sample array which allows
indexed based checks against the expiry cache array.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192921.590362974@linutronix.de
Use the array based expiry cache in check_thread_timers() and convert the
store in check_process_timers() for consistency.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192921.408222378@linutronix.de
The expiry cache can now be accessed as an array. Replace the per clock
checks with a simple comparison of the clock indexed array member.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192921.303316423@linutronix.de
Now that the expiry cache can be accessed as an array, the per clock
checking can be reduced to just comparing the corresponding array elements.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192921.212129449@linutronix.de
Using struct task_cputime for the expiry cache is a pretty odd choice and
comes with magic defines to rename the fields for usage in the expiry
cache.
struct task_cputime is basically a u64 array with 3 members, but it has
distinct members.
The expiry cache content is different than the content of task_cputime
because
expiry[PROF] = task_cputime.stime + task_cputime.utime
expiry[VIRT] = task_cputime.utime
expiry[SCHED] = task_cputime.sum_exec_runtime
So there is no direct mapping between task_cputime and the expiry cache and
the #define based remapping is just a horrible hack.
Having the expiry cache array based allows further simplification of the
expiry code.
To avoid an all in one cleanup which is hard to review add a temporary
anonymous union into struct task_cputime which allows array based access to
it. That requires to reorder the members. Add a build time sanity check to
validate that the members are at the same place.
The union and the build time checks will be removed after conversion.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192921.105793824@linutronix.de
The expiry cache belongs into the posix_cputimers container where the other
cpu timers information is.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192921.014444012@linutronix.de
Per task/process data of posix CPU timers is all over the place which
makes the code hard to follow and requires ifdeffery.
Create a container to hold all this information in one place, so data is
consolidated and the ifdeffery can be confined to the posix timer header
file and removed from places like fork.
As a first step, move the cpu_timers list head array into the new struct
and clean up the initializers and simplify fork. The remaining #ifdef in
fork will be removed later.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192920.819418976@linutronix.de
The functions have only one caller left. No point in having them.
Move the almost duplicated code into the caller and simplify it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192920.729298382@linutronix.de
Now that the sample functions have no return value anymore, the result can
simply be returned instead of using pointer indirection.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192920.535079278@linutronix.de
All callers hand in a valdiated clock id. Remove the return value which was
unchecked in most places anyway.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192920.430475832@linutronix.de
set_process_cpu_timer() checks already whether the clock id is valid. No
point in checking the return value of the sample function. That allows to
simplify the sample function later.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192920.339725769@linutronix.de
Extract the clock ID (PROF/VIRT/SCHED) from the clock selector and use it
as argument to the sample functions. That allows to simplify them once all
callers are fixed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192920.245357769@linutronix.de
Extract the clock ID (PROF/VIRT/SCHED) from the clock selector and use it
as argument to the sample functions. That allows to simplify them once all
callers are fixed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192920.155487201@linutronix.de
Extract the clock ID (PROF/VIRT/SCHED) from the clock selector and use it
as argument to the sample functions. That allows to simplify them once all
callers are fixed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192920.050770464@linutronix.de
cpu_clock_sample_group() and cpu_timer_sample_group() are almost the
same. Before the rename one called thread_group_cputimer() and the other
thread_group_cputime(). Really intuitive function names.
Consolidate the functions and also avoid the thread traversal when
the thread group's accounting is already active.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192919.960966884@linutronix.de
thread_group_cputimer() is a complete misnomer. The function does two things:
- For arming process wide timers it makes sure that the atomic time
storage is up to date. If no cpu timer is armed yet, then the atomic
time storage is not updated by the scheduler for performance reasons.
In that case a full summing up of all threads needs to be done and the
update needs to be enabled.
- Samples the current time into the caller supplied storage.
Rename it to thread_group_start_cputime(), make it static and fixup the
callsite.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192919.869350319@linutronix.de
The thread group accounting is active, otherwise the expiry function would
not be running. Sample the thread group time directly.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192919.780348088@linutronix.de
get_itimer() locks sighand lock and checks whether the timer is already
expired. If it is not expired then the thread group cputime accounting is
already enabled. Use the sampling function not the one which is meant for
starting a timer.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192919.689713638@linutronix.de
get_itimer() needs a sample of the current thread group cputime. It invokes
thread_group_cputimer() - which is a misnomer. That function also starts
eventually the group cputime accouting which is bogus because the
accounting is already active when a timer is armed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192919.599658199@linutronix.de
Replace the next slightly different copy of permission checks. That also
removes the necessarity to check the return value of the sample functions
because the clock id is already validated.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192919.414813172@linutronix.de
The code contains three slightly different copies of validating whether a
given clock resolves to a valid task and whether the current caller has
permissions to access it.
Create central functions. Replace check_clock() as a first step and rename
it to something sensible.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190821192919.326097175@linutronix.de
In some cases, ordinary (non-AUX) events can generate data for AUX events.
For example, PEBS events can come out as records in the Intel PT stream
instead of their usual DS records, if configured to do so.
One requirement for such events is to consistently schedule together, to
ensure that the data from the "AUX output" events isn't lost while their
corresponding AUX event is not scheduled. We use grouping to provide this
guarantee: an "AUX output" event can be added to a group where an AUX event
is a group leader, and provided that the former supports writing to the
latter.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: kan.liang@linux.intel.com
Link: https://lkml.kernel.org/r/20190806084606.4021-2-alexander.shishkin@linux.intel.com
Fast switching path only emits an event for the CPU of interest, whereas the
regular path emits an event for all the CPUs that had their frequency changed,
i.e. all the CPUs sharing the same policy.
With the current behavior, looking at cpu_frequency event for a given CPU that
is using the fast switching path will not give the correct frequency signal.
Signed-off-by: Douglas RAILLARD <douglas.raillard@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Introduce BPF_F_TEST_STATE_FREQ flag to stress test parentage chain
and state pruning.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull networking fixes from David Miller:
1) Use 32-bit index for tails calls in s390 bpf JIT, from Ilya
Leoshkevich.
2) Fix missed EPOLLOUT events in TCP, from Eric Dumazet. Same fix for
SMC from Jason Baron.
3) ipv6_mc_may_pull() should return 0 for malformed packets, not
-EINVAL. From Stefano Brivio.
4) Don't forget to unpin umem xdp pages in error path of
xdp_umem_reg(). From Ivan Khoronzhuk.
5) Fix sta object leak in mac80211, from Johannes Berg.
6) Fix regression by not configuring PHYLINK on CPU port of bcm_sf2
switches. From Florian Fainelli.
7) Revert DMA sync removal from r8169 which was causing regressions on
some MIPS Loongson platforms. From Heiner Kallweit.
8) Use after free in flow dissector, from Jakub Sitnicki.
9) Fix NULL derefs of net devices during ICMP processing across
collect_md tunnels, from Hangbin Liu.
10) proto_register() memory leaks, from Zhang Lin.
11) Set NLM_F_MULTI flag in multipart netlink messages consistently,
from John Fastabend.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (66 commits)
r8152: Set memory to all 0xFFs on failed reg reads
openvswitch: Fix conntrack cache with timeout
ipv4: mpls: fix mpls_xmit for iptunnel
nexthop: Fix nexthop_num_path for blackhole nexthops
net: rds: add service level support in rds-info
net: route dump netlink NLM_F_MULTI flag missing
s390/qeth: reject oversized SNMP requests
sock: fix potential memory leak in proto_register()
MAINTAINERS: Add phylink keyword to SFF/SFP/SFP+ MODULE SUPPORT
xfrm/xfrm_policy: fix dst dev null pointer dereference in collect_md mode
ipv4/icmp: fix rt dst dev null pointer dereference
openvswitch: Fix log message in ovs conntrack
bpf: allow narrow loads of some sk_reuseport_md fields with offset > 0
bpf: fix use after free in prog symbol exposure
bpf: fix precision tracking in presence of bpf2bpf calls
flow_dissector: Fix potential use-after-free on BPF_PROG_DETACH
Revert "r8169: remove not needed call to dma_sync_single_for_device"
ipv6: propagate ipv6_add_dev's error returns out of ipv6_find_idev
net/ncsi: Fix the payload copying for the request coming from Netlink
qed: Add cleanup in qed_slowpath_start()
...
An arm64 kernel configured with
CONFIG_KPROBES=y
CONFIG_KALLSYMS=y
# CONFIG_KALLSYMS_ALL is not set
CONFIG_KALLSYMS_BASE_RELATIVE=y
reports the following kprobe failure:
[ 0.032677] kprobes: failed to populate blacklist: -22
[ 0.033376] Please take care of using kprobes.
It appears that kprobe fails to retrieve the symbol at address
0xffff000010081000, despite this symbol being in System.map:
ffff000010081000 T __exception_text_start
This symbol is part of the first group of aliases in the
kallsyms_offsets array (symbol names generated using ugly hacks in
scripts/kallsyms.c):
kallsyms_offsets:
.long 0x1000 // do_undefinstr
.long 0x1000 // efi_header_end
.long 0x1000 // _stext
.long 0x1000 // __exception_text_start
.long 0x12b0 // do_cp15instr
Looking at the implementation of get_symbol_pos(), it returns the
lowest index for aliasing symbols. In this case, it return 0.
But kallsyms_lookup_size_offset() considers 0 as a failure, which
is obviously wrong (there is definitely a valid symbol living there).
In turn, the kprobe blacklisting stops abruptly, hence the original
error.
A CONFIG_KALLSYMS_ALL kernel wouldn't fail as there is always
some random symbols at the beginning of this array, which are never
looked up via kallsyms_lookup_size_offset.
Fix it by considering that get_symbol_pos() is always successful
(which is consistent with the other uses of this function).
Fixes: ffc5089196 ("[PATCH] Create kallsyms_lookup_size_offset()")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Now __irq_build_affinity_masks() spreads vectors evenly per node, but there
is a case that not all vectors have been spread when each numa node has a
different number of CPUs which triggers the warning in the spreading code.
Improve the spreading algorithm by
- assigning vectors according to the ratio of the number of CPUs on a node
to the number of remaining CPUs.
- running the assignment from smaller nodes to bigger nodes to guarantee
that every active node gets allocated at least one vector.
This ensures that all vectors are spread out. Asided of that the spread
becomes more fair if the nodes have different number of CPUs.
For example, on the following machine:
CPU(s): 16
On-line CPU(s) list: 0-15
Thread(s) per core: 1
Core(s) per socket: 8
Socket(s): 2
NUMA node(s): 2
...
NUMA node0 CPU(s): 0,1,3,5-9,11,13-15
NUMA node1 CPU(s): 2,4,10,12
When a driver requests to allocate 8 vectors, the following spread results:
irq 31, cpu list 2,4
irq 32, cpu list 10,12
irq 33, cpu list 0-1
irq 34, cpu list 3,5
irq 35, cpu list 6-7
irq 36, cpu list 8-9
irq 37, cpu list 11,13
irq 38, cpu list 14-15
So Node 0 has now 6 and Node 1 has 2 vectors assigned. The original
algorithm assigned 4 vectors on each node which was unfair versus Node 0.
[ tglx: Massaged changelog ]
Reported-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Link: https://lkml.kernel.org/r/20190816022849.14075-3-ming.lei@redhat.com
One invariant of __irq_build_affinity_masks() is that all CPUs in the
specified masks (cpu_mask AND node_to_cpumask for each node) should be
covered during the spread. Even though all requested vectors have been
reached, it's still required to spread vectors among remained CPUs. A
similar policy has been taken in case of 'numvecs <= nodes' already.
So remove the following check inside the loop:
if (done >= numvecs)
break;
Meantime assign at least 1 vector for remaining nodes if 'numvecs' vectors
have been handled already.
Also, if the specified cpumask for one numa node is empty, simply do not
spread vectors on this node.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190816022849.14075-2-ming.lei@redhat.com
Since BPF constant blinding is performed after the verifier pass, the
ALU32 instructions inserted for doubleword immediate loads don't have a
corresponding zext instruction. This is causing a kernel oops on powerpc
and can be reproduced by running 'test_cgroup_storage' with
bpf_jit_harden=2.
Fix this by emitting BPF_ZEXT during constant blinding if
prog->aux->verifier_zext is set.
Fixes: a4b1d3c1dd ("bpf: verifier: insert zero extension according to analysis result")
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull timekeeping fix from Thomas Gleixner:
"A single fix for a regression caused by the generic VDSO
implementation where a math overflow causes CLOCK_BOOTTIME to become a
random number generator"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping/vsyscall: Prevent math overflow in BOOTTIME update
Pull scheduler fix from Thomas Gleixner:
"Handle the worker management in situations where a task is scheduled
out on a PI lock contention correctly and schedule a new worker if
possible"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Schedule new worker even if PI-blocked
Pull perf fixes from Thomas Gleixner:
"Two small fixes for kprobes and perf:
- Prevent a deadlock in kprobe_optimizer() causes by reverse lock
ordering
- Fix a comment typo"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kprobes: Fix potential deadlock in kprobe_optimizer()
perf/x86: Fix typo in comment
Pull irq fix from Thomas Gleixner:
"A single fix for a imbalanced kobject operation in the irq decriptor
code which was unearthed by the new warnings in the kobject code"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Properly pair kobject_del() with kobject_add()
Mergr misc fixes from Andrew Morton:
"11 fixes"
Mostly VM fixes, one psi polling fix, and one parisc build fix.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm/kasan: fix false positive invalid-free reports with CONFIG_KASAN_SW_TAGS=y
mm/zsmalloc.c: fix race condition in zs_destroy_pool
mm/zsmalloc.c: migration can leave pages in ZS_EMPTY indefinitely
mm, page_owner: handle THP splits correctly
userfaultfd_release: always remove uffd flags and clear vm_userfaultfd_ctx
psi: get poll_work to run when calling poll syscall next time
mm: memcontrol: flush percpu vmevents before releasing memcg
mm: memcontrol: flush percpu vmstats before releasing memcg
parisc: fix compilation errrors
mm, page_alloc: move_freepages should not examine struct page of reserved memory
mm/z3fold.c: fix race between migration and destruction
Two fixes for regressions in this merge window:
- select the Kconfig symbols for the noncoherent dma arch helpers
on arm if swiotlb is selected, not just for LPAE to not break then
Xen build, that uses swiotlb indirectly through swiotlb-xen
- fix the page allocator fallback in dma_alloc_contiguous if the CMA
allocation fails
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Merge tag 'dma-mapping-5.3-5' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fixes from Christoph Hellwig:
"Two fixes for regressions in this merge window:
- select the Kconfig symbols for the noncoherent dma arch helpers on
arm if swiotlb is selected, not just for LPAE to not break then Xen
build, that uses swiotlb indirectly through swiotlb-xen
- fix the page allocator fallback in dma_alloc_contiguous if the CMA
allocation fails"
* tag 'dma-mapping-5.3-5' of git://git.infradead.org/users/hch/dma-mapping:
dma-direct: fix zone selection after an unaddressable CMA allocation
arm: select the dma-noncoherent symbols for all swiotlb builds
Only when calling the poll syscall the first time can user receive
POLLPRI correctly. After that, user always fails to acquire the event
signal.
Reproduce case:
1. Get the monitor code in Documentation/accounting/psi.txt
2. Run it, and wait for the event triggered.
3. Kill and restart the process.
The question is why we can end up with poll_scheduled = 1 but the work
not running (which would reset it to 0). And the answer is because the
scheduling side sees group->poll_kworker under RCU protection and then
schedules it, but here we cancel the work and destroy the worker. The
cancel needs to pair with resetting the poll_scheduled flag.
Link: http://lkml.kernel.org/r/1566357985-97781-1-git-send-email-joseph.qi@linux.alibaba.com
Signed-off-by: Jason Xing <kerneljasonxing@linux.alibaba.com>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Caspar Zhang <caspar@linux.alibaba.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel Borkmann says:
====================
pull-request: bpf 2019-08-24
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) Fix verifier precision tracking with BPF-to-BPF calls, from Alexei.
2) Fix a use-after-free in prog symbol exposure, from Daniel.
3) Several s390x JIT fixes plus BE related fixes in BPF kselftests, from Ilya.
4) Fix memory leak by unpinning XDP umem pages in error path, from Ivan.
5) Fix a potential use-after-free on flow dissector detach, from Jakub.
6) Fix bpftool to close prog fd after showing metadata, from Quentin.
7) BPF kselftest config and TEST_PROGS_EXTENDED fixes, from Anders.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
syzkaller managed to trigger the warning in bpf_jit_free() which checks via
bpf_prog_kallsyms_verify_off() for potentially unlinked JITed BPF progs
in kallsyms, and subsequently trips over GPF when walking kallsyms entries:
[...]
8021q: adding VLAN 0 to HW filter on device batadv0
8021q: adding VLAN 0 to HW filter on device batadv0
WARNING: CPU: 0 PID: 9869 at kernel/bpf/core.c:810 bpf_jit_free+0x1e8/0x2a0
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 9869 Comm: kworker/0:7 Not tainted 5.0.0-rc8+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events bpf_prog_free_deferred
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x113/0x167 lib/dump_stack.c:113
panic+0x212/0x40b kernel/panic.c:214
__warn.cold.8+0x1b/0x38 kernel/panic.c:571
report_bug+0x1a4/0x200 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:178 [inline]
do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:bpf_jit_free+0x1e8/0x2a0
Code: 02 4c 89 e2 83 e2 07 38 d0 7f 08 84 c0 0f 85 86 00 00 00 48 ba 00 02 00 00 00 00 ad de 0f b6 43 02 49 39 d6 0f 84 5f fe ff ff <0f> 0b e9 58 fe ff ff 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1
RSP: 0018:ffff888092f67cd8 EFLAGS: 00010202
RAX: 0000000000000007 RBX: ffffc90001947000 RCX: ffffffff816e9d88
RDX: dead000000000200 RSI: 0000000000000008 RDI: ffff88808769f7f0
RBP: ffff888092f67d00 R08: fffffbfff1394059 R09: fffffbfff1394058
R10: fffffbfff1394058 R11: ffffffff89ca02c7 R12: ffffc90001947002
R13: ffffc90001947020 R14: ffffffff881eca80 R15: ffff88808769f7e8
BUG: unable to handle kernel paging request at fffffbfff400d000
#PF error: [normal kernel read fault]
PGD 21ffee067 P4D 21ffee067 PUD 21ffed067 PMD 9f942067 PTE 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 9869 Comm: kworker/0:7 Not tainted 5.0.0-rc8+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events bpf_prog_free_deferred
RIP: 0010:bpf_get_prog_addr_region kernel/bpf/core.c:495 [inline]
RIP: 0010:bpf_tree_comp kernel/bpf/core.c:558 [inline]
RIP: 0010:__lt_find include/linux/rbtree_latch.h:115 [inline]
RIP: 0010:latch_tree_find include/linux/rbtree_latch.h:208 [inline]
RIP: 0010:bpf_prog_kallsyms_find+0x107/0x2e0 kernel/bpf/core.c:632
Code: 00 f0 ff ff 44 38 c8 7f 08 84 c0 0f 85 fa 00 00 00 41 f6 45 02 01 75 02 0f 0b 48 39 da 0f 82 92 00 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 74 08 3c 03 0f 8e 45 01 00 00 8b 03 48 c1 e0
[...]
Upon further debugging, it turns out that whenever we trigger this
issue, the kallsyms removal in bpf_prog_ksym_node_del() was /skipped/
but yet bpf_jit_free() reported that the entry is /in use/.
Problem is that symbol exposure via bpf_prog_kallsyms_add() but also
perf_event_bpf_event() were done /after/ bpf_prog_new_fd(). Once the
fd is exposed to the public, a parallel close request came in right
before we attempted to do the bpf_prog_kallsyms_add().
Given at this time the prog reference count is one, we start to rip
everything underneath us via bpf_prog_release() -> bpf_prog_put().
The memory is eventually released via deferred free, so we're seeing
that bpf_jit_free() has a kallsym entry because we added it from
bpf_prog_load() but /after/ bpf_prog_put() from the remote CPU.
Therefore, move both notifications /before/ we install the fd. The
issue was never seen between bpf_prog_alloc_id() and bpf_prog_new_fd()
because upon bpf_prog_get_fd_by_id() we'll take another reference to
the BPF prog, so we're still holding the original reference from the
bpf_prog_load().
Fixes: 6ee52e2a3f ("perf, bpf: Introduce PERF_RECORD_BPF_EVENT")
Fixes: 74451e66d5 ("bpf: make jited programs visible in traces")
Reported-by: syzbot+bd3bba6ff3fcea7a6ec6@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Song Liu <songliubraving@fb.com>
While adding extra tests for precision tracking and extra infra
to adjust verifier heuristics the existing test
"calls: cross frame pruning - liveness propagation" started to fail.
The root cause is the same as described in verifer.c comment:
* Also if parent's curframe > frame where backtracking started,
* the verifier need to mark registers in both frames, otherwise callees
* may incorrectly prune callers. This is similar to
* commit 7640ead939 ("bpf: verifier: make sure callees don't prune with caller differences")
* For now backtracking falls back into conservative marking.
Turned out though that returning -ENOTSUPP from backtrack_insn() and
doing mark_all_scalars_precise() in the current parentage chain is not enough.
Depending on how is_state_visited() heuristic is creating parentage chain
it's possible that callee will incorrectly prune caller.
Fix the issue by setting precise=true earlier and more aggressively.
Before this fix the precision tracking _within_ functions that don't do
bpf2bpf calls would still work. Whereas now precision tracking is completely
disabled when bpf2bpf calls are present anywhere in the program.
No difference in cilium tests (they don't have bpf2bpf calls).
No difference in test_progs though some of them have bpf2bpf calls,
but precision tracking wasn't effective there.
Fixes: b5dc0163d8 ("bpf: precise scalar_value tracking")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The VDSO update for CLOCK_BOOTTIME has a overflow issue as it shifts the
nanoseconds based boot time offset left by the clocksource shift. That
overflows once the boot time offset becomes large enough. As a consequence
CLOCK_BOOTTIME in the VDSO becomes a random number causing applications to
misbehave.
Fix it by storing a timespec64 representation of the offset when boot time
is adjusted and add that to the MONOTONIC base time value in the vdso data
page. Using the timespec64 representation avoids a 64bit division in the
update code.
Fixes: 44f57d788e ("timekeeping: Provide a generic update_vsyscall() implementation")
Reported-by: Chris Clayton <chris2553@googlemail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908221257580.1983@nanos.tec.linutronix.de
Pull RCU and LKMM changes from Paul E. McKenney:
- A few more RCU flavor consolidation cleanups.
- Miscellaneous fixes.
- Updates to RCU's list-traversal macros improving lockdep usability.
- Torture-test updates.
- Forward-progress improvements for no-CBs CPUs: Avoid ignoring
incoming callbacks during grace-period waits.
- Forward-progress improvements for no-CBs CPUs: Use ->cblist
structure to take advantage of others' grace periods.
- Also added a small commit that avoids needlessly inflicting
scheduler-clock ticks on callback-offloaded CPUs.
- Forward-progress improvements for no-CBs CPUs: Reduce contention
on ->nocb_lock guarding ->cblist.
- Forward-progress improvements for no-CBs CPUs: Add ->nocb_bypass
list to further reduce contention on ->nocb_lock guarding ->cblist.
- LKMM updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
From rdma.git
Jason Gunthorpe says:
====================
This is a collection of general cleanups for ODP to clarify some of the
flows around umem creation and use of the interval tree.
====================
The branch is based on v5.3-rc5 due to dependencies, and is being taken
into hmm.git due to dependencies in the next patches.
* odp_fixes:
RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr
RDMA/mlx5: Use ib_umem_start instead of umem.address
RDMA/core: Make invalidate_range a device operation
RDMA/odp: Use kvcalloc for the dma_list and page_list
RDMA/odp: Check for overflow when computing the umem_odp end
RDMA/odp: Provide ib_umem_odp_release() to undo the allocs
RDMA/odp: Split creating a umem_odp from ib_umem_get
RDMA/odp: Make the three ways to create a umem_odp clear
RMDA/odp: Consolidate umem_odp initialization
RDMA/odp: Make it clearer when a umem is an implicit ODP umem
RDMA/odp: Iterate over the whole rbtree directly
RDMA/odp: Use the common interval tree library instead of generic
RDMA/mlx5: Fix MR npages calculation for IB_ACCESS_HUGETLB
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Warning when p == NULL and then proceeding and dereferencing p does not
make any sense as the kernel will crash with a NULL pointer dereference
right away.
Bailing out when p == NULL and returning an error code does not cure the
underlying problem which caused p to be NULL. Though it might allow to
do proper debugging.
Same applies to the clock id check in set_process_cpu_timer().
Clean them up and make them return without trying to do further damage.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190819143801.846497772@linutronix.de
PERF_EVENT_IOC_SET_BPF supports uprobes since v4.3, and tracepoints
since v4.7 via commit 04a22fae4c ("tracing, perf: Implement BPF
programs attached to uprobes"), and commit 98b5c2c65c ("perf, bpf:
allow bpf programs attach to tracepoints") respectively.
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
migration_base is used as a placeholder when an hrtimer is migrated to a
different CPU. In the case that hrtimer_cancel_wait_running() hits a timer
which is currently migrated it would pointlessly acquire the expiry lock of
the migration base, which is even not initialized.
Surely it could be initialized, but there is absolutely no point in
acquiring this lock because the timer is guaranteed not to run it's
callback for which the caller waits to finish on that base. So it would
just do the inc/lock/dec/unlock dance for nothing.
As the base switch is short and non-preemptible, there is no issue when the
wait function returns immediately.
The timer base and base->cpu_base cannot be NULL in the code path which is
invoking that, so just replace those checks with a check whether base is
migration base.
[ tglx: Updated from RT patch. Massaged changelog. Added comment. ]
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190821092409.13225-4-julien.grall@arm.com
The update to timer->base is protected by the base->cpu_base->lock().
However, hrtimer_cancel_wait_running() does access it lockless. So the
compiler is allowed to refetch timer->base which can cause havoc when the
timer base is changed concurrently.
Use READ_ONCE() to prevent this.
[ tglx: Adapted from a RT patch ]
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190821092409.13225-2-julien.grall@arm.com
Certain architecture specific operating modes (e.g., in powerpc machine
check handler that is unable to access vmalloc memory), the
search_exception_tables cannot be called because it also searches the
module exception tables if entry is not found in the kernel exception
table.
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820081352.8641-5-santosh@fossix.org
We should keep the case of "#define debug_align(X) (X)" for all arches
without CONFIG_HAS_STRICT_MODULE_RWX ability, which would save people, who
are sensitive to system size, a lot of memory when using modules,
especially for embedded systems. This is also the intention of the
original #ifdef... statement and still valid for now.
Note that this still keeps the effect of the fix of the following commit,
38f054d549 ("modules: always page-align module section allocations"),
since when CONFIG_ARCH_HAS_STRICT_MODULE_RWX is enabled, module pages are
aligned.
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
The network_latency and network_throughput flags for PM-QoS have not
found much use in drivers or in userspace since they were introduced.
Commit 4a733ef1be ("mac80211: remove PM-QoS listener") removed the
only user PM_QOS_NETWORK_LATENCY in the kernel a while ago and there
don't seem to be any userspace tools using the character device files
either.
PM_QOS_MEMORY_BANDWIDTH was never even added to the trace events.
Remove all the flags except cpu_dma_latency.
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add an ID and a device pointer to 'struct wakeup_source'. Use them to to
expose wakeup sources statistics in sysfs under
/sys/class/wakeup/wakeup<ID>/*.
Co-developed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Tri Vo <trong@android.com>
Tested-by: Kalesh Singh <kaleshsingh@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
kernel/power/wakelock.c duplicates wakeup source creation and
registration code from drivers/base/power/wakeup.c.
Change struct wakelock's wakeup source to a pointer and use
wakeup_source_register() function to create and register said wakeup
source. Use wakeup_source_unregister() on cleanup path.
Signed-off-by: Tri Vo <trong@android.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The new dma_alloc_contiguous hides if we allocate CMA or regular
pages, and thus fails to retry a ZONE_NORMAL allocation if the CMA
allocation succeeds but isn't addressable. That means we either fail
outright or dip into a small zone that might not succeed either.
Thanks to Hillf Danton for debugging this issue.
Fixes: b1d2dc009d ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Reported-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
The comment above cleanup_timers() is outdated. The timers are only removed
from the task/process list heads but not modified in any other way.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190819143801.747233612@linutronix.de
The handling of a priority inversion between timer cancelling and a a not
well defined possible preemption of softirq kthread is not very clear.
Especially in the posix timers side it's unclear why there is a specific RT
wait callback.
All the nice explanations can be found in the initial changelog of
f61eff83ce (hrtimer: Prepare support for PREEMPT_RT").
Extract the detailed informations from there and put it into comments.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190820132656.GC2093@lenoir
Posix timer delete retry loops are affected by the same priority inversion
and live lock issues as the other timers.
Provide a RT specific synchronization function which keeps a reference to
the timer by holding rcu read lock to prevent the timer from being freed,
dropping the timer lock and invoking the timer specific wait function via a
new callback.
This does not yet cover posix CPU timers because they need more special
treatment on PREEMPT_RT.
[ This is folded into the original attempt which did not use a callback. ]
Originally-by: Anna-Maria Gleixenr <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190819143801.656864506@linutronix.de
Require that arg{3,4,5} of the PR_{SET,GET}_TAGGED_ADDR_CTRL prctl and
arg2 of the PR_GET_TAGGED_ADDR_CTRL prctl() are zero rather than ignored
for future extensions.
Acked-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Add a new command for the bpf() system call: BPF_BTF_GET_NEXT_ID is used
to cycle through all BTF objects loaded on the system.
The motivation is to be able to inspect (list) all BTF objects presents
on the system.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Implement the show_fdinfo hook for BTF FDs file operations, and make it
print the id of the BTF object. This allows for a quick retrieval of the
BTF id from its FD; or it can help understanding what type of object
(BTF) the file descriptor points to.
v2:
- Do not expose data_size, only btf_id, in FD info.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The kvmppc ultravisor code wants a device private memory pool that is
system wide and not attached to a device. Instead of faking up one
provide a low-level memremap_pages for it.
Link: https://lore.kernel.org/r/20190818090557.17853-5-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Just clean up for early failures and then piggy back on
devm_memremap_pages_release. This helps with a pending not device managed
version of devm_memremap_pages.
Link: https://lore.kernel.org/r/20190818090557.17853-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The dev field in struct dev_pagemap is only used to print dev_name in two
places, which are at best nice to have. Just remove the field and thus
the name in those two messages.
Link: https://lore.kernel.org/r/20190818090557.17853-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Factor out the guts of devm_request_free_mem_region so that we can
implement both a device managed and a manually release version as tiny
wrappers around it.
Link: https://lore.kernel.org/r/20190818090557.17853-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This is a significant simplification, it eliminates all the remaining
'hmm' stuff in mm_struct, eliminates krefing along the critical notifier
paths, and takes away all the ugly locking and abuse of page_table_lock.
mmu_notifier_get() provides the single struct hmm per struct mm which
eliminates mm->hmm.
It also directly guarantees that no mmu_notifier op callback is callable
while concurrent free is possible, this eliminates all the krefs inside
the mmu_notifier callbacks.
The remaining krefs in the range code were overly cautious, drivers are
already not permitted to free the mirror while a range exists.
Link: https://lore.kernel.org/r/20190806231548.25242-6-jgg@ziepe.ca
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Systems in lockdown mode should block the kexec of untrusted kernels.
For x86 and ARM we can ensure that a kernel is trustworthy by validating
a PE signature, but this isn't possible on other architectures. On those
platforms we can use IMA digital signatures instead. Add a function to
determine whether IMA has or will verify signatures for a given event type,
and if so permit kexec_file() even if the kernel is otherwise locked down.
This is restricted to cases where CONFIG_INTEGRITY_TRUSTED_KEYRING is set
in order to prevent an attacker from loading additional keys at runtime.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: linux-integrity@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
Disallow the use of certain perf facilities that might allow userspace to
access kernel data.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>
bpf_read() and bpf_read_str() could potentially be abused to (eg) allow
private keys in kernel memory to be leaked. Disable them if the kernel
has been locked down in confidentiality mode.
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
cc: netdev@vger.kernel.org
cc: Chun-Yi Lee <jlee@suse.com>
cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: James Morris <jmorris@namei.org>
Disallow the creation of perf and ftrace kprobes when the kernel is
locked down in confidentiality mode by preventing their registration.
This prevents kprobes from being used to access kernel memory to steal
crypto data, but continues to allow the use of kprobes from signed
modules.
Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: davem@davemloft.net
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>
Provided an annotation for module parameters that specify hardware
parameters (such as io ports, iomem addresses, irqs, dma channels, fixed
dma buffers and other types).
Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Jessica Yu <jeyu@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>
There is currently no way to verify the resume image when returning
from hibernate. This might compromise the signed modules trust model,
so until we can work with signed hibernate images we disable it when the
kernel is locked down.
Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: rjw@rjwysocki.net
Cc: pavel@ucw.cz
cc: linux-pm@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
When KEXEC_SIG is not enabled, kernel should not load images through
kexec_file systemcall if the kernel is locked down.
[Modified by David Howells to fit with modifications to the previous patch
and to return -EPERM if the kernel is locked down for consistency with
other lockdowns. Modified by Matthew Garrett to remove the IMA
integration, which will be replaced by integrating with the IMA
architecture policy patches.]
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
cc: kexec@lists.infradead.org
Signed-off-by: James Morris <jmorris@namei.org>
This is a preparatory patch for kexec_file_load() lockdown. A locked down
kernel needs to prevent unsigned kernel images from being loaded with
kexec_file_load(). Currently, the only way to force the signature
verification is compiling with KEXEC_VERIFY_SIG. This prevents loading
usigned images even when the kernel is not locked down at runtime.
This patch splits KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE.
Analogous to the MODULE_SIG and MODULE_SIG_FORCE for modules, KEXEC_SIG
turns on the signature verification but allows unsigned images to be
loaded. KEXEC_SIG_FORCE disallows images without a valid signature.
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
cc: kexec@lists.infradead.org
Signed-off-by: James Morris <jmorris@namei.org>
The kexec_load() syscall permits the loading and execution of arbitrary
code in ring 0, which is something that lock-down is meant to prevent. It
makes sense to disable kexec_load() in this situation.
This does not affect kexec_file_load() syscall which can check for a
signature on the image to be booted.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Dave Young <dyoung@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
cc: kexec@lists.infradead.org
Signed-off-by: James Morris <jmorris@namei.org>
If the kernel is locked down, require that all modules have valid
signatures that we can verify.
I have adjusted the errors generated:
(1) If there's no signature (ENODATA) or we can't check it (ENOPKG,
ENOKEY), then:
(a) If signatures are enforced then EKEYREJECTED is returned.
(b) If there's no signature or we can't check it, but the kernel is
locked down then EPERM is returned (this is then consistent with
other lockdown cases).
(2) If the signature is unparseable (EBADMSG, EINVAL), the signature fails
the check (EKEYREJECTED) or a system error occurs (eg. ENOMEM), we
return the error we got.
Note that the X.509 code doesn't check for key expiry as the RTC might not
be valid or might not have been transferred to the kernel's clock yet.
[Modified by Matthew Garrett to remove the IMA integration. This will
be replaced with integration with the IMA architecture policy
patchset.]
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <matthewgarrett@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Jessica Yu <jeyu@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>
Pull kernel thread signal handling fix from Eric Biederman:
"I overlooked the fact that kernel threads are created with all signals
set to SIG_IGN, and accidentally caused a regression in cifs and drbd
when replacing force_sig with send_sig.
This is my fix for that regression. I add a new function
allow_kernel_signal which allows kernel threads to receive signals
sent from the kernel, but continues to ignore all signals sent from
userspace. This ensures the user space interface for cifs and drbd
remain the same.
These kernel threads depend on blocking networking calls which block
until something is received or a signal is pending. Making receiving
of signals somewhat necessary for these kernel threads.
Perhaps someday we can cleanup those interfaces and remove
allow_kernel_signal. If not allow_kernel_signal is pretty trivial and
clearly documents what is going on so I don't think we will mind
carrying it"
* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
signal: Allow cifs and drbd to receive their terminating signals
If alloc_descs() fails before irq_sysfs_init() has run, free_desc() in the
cleanup path will call kobject_del() even though the kobject has not been
added with kobject_add().
Fix this by making the call to kobject_del() conditional on whether
irq_sysfs_init() has run.
This problem surfaced because commit aa30f47cf6 ("kobject: Add support
for default attribute groups to kobj_type") makes kobject_del() stricter
about pairing with kobject_add(). If the pairing is incorrrect, a WARNING
and backtrace occur in sysfs_remove_group() because there is no parent.
[ tglx: Add a comment to the code and make it work with CONFIG_SYSFS=n ]
Fixes: ecb3f394c5 ("genirq: Expose interrupt information through sysfs")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1564703564-4116-1-git-send-email-mikelley@microsoft.com
Switch force_irqthreads from a boot time modifiable variable to a compile
time constant when CONFIG_PREEMPT_RT is enabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190816160923.12855-1-bigeasy@linutronix.de
My recent to change to only use force_sig for a synchronous events
wound up breaking signal reception cifs and drbd. I had overlooked
the fact that by default kthreads start out with all signals set to
SIG_IGN. So a change I thought was safe turned out to have made it
impossible for those kernel thread to catch their signals.
Reverting the work on force_sig is a bad idea because what the code
was doing was very much a misuse of force_sig. As the way force_sig
ultimately allowed the signal to happen was to change the signal
handler to SIG_DFL. Which after the first signal will allow userspace
to send signals to these kernel threads. At least for
wake_ack_receiver in drbd that does not appear actively wrong.
So correct this problem by adding allow_kernel_signal that will allow
signals whose siginfo reports they were sent by the kernel through,
but will not allow userspace generated signals, and update cifs and
drbd to call allow_kernel_signal in an appropriate place so that their
thread can receive this signal.
Fixing things this way ensures that userspace won't be able to send
signals and cause problems, that it is clear which signals the
threads are expecting to receive, and it guarantees that nothing
else in the system will be affected.
This change was partly inspired by similar cifs and drbd patches that
added allow_signal.
Reported-by: ronnie sahlberg <ronniesahlberg@gmail.com>
Reported-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Tested-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Cc: Steve French <smfrench@gmail.com>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Fixes: 247bc9470b ("cifs: fix rmmod regression in cifs.ko caused by force_sig changes")
Fixes: 72abe3bcf0 ("signal/cifs: Fix cifs_put_tcp_session to call send_sig instead of force_sig")
Fixes: fee109901f ("signal/drbd: Use send_sig not force_sig")
Fixes: 3cf5d076fb ("signal: Remove task parameter from force_sig")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
klp_module_coming() is called for every module appearing in the system.
It sets obj->mod to a patched module for klp_object obj. Unfortunately
it leaves it set even if an error happens later in the function and the
patched module is not allowed to be loaded.
klp_is_object_loaded() uses obj->mod variable and could currently give a
wrong return value. The bug is probably harmless as of now.
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
lockdep reports the following deadlock scenario:
WARNING: possible circular locking dependency detected
kworker/1:1/48 is trying to acquire lock:
000000008d7a62b2 (text_mutex){+.+.}, at: kprobe_optimizer+0x163/0x290
but task is already holding lock:
00000000850b5e2d (module_mutex){+.+.}, at: kprobe_optimizer+0x31/0x290
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (module_mutex){+.+.}:
__mutex_lock+0xac/0x9f0
mutex_lock_nested+0x1b/0x20
set_all_modules_text_rw+0x22/0x90
ftrace_arch_code_modify_prepare+0x1c/0x20
ftrace_run_update_code+0xe/0x30
ftrace_startup_enable+0x2e/0x50
ftrace_startup+0xa7/0x100
register_ftrace_function+0x27/0x70
arm_kprobe+0xb3/0x130
enable_kprobe+0x83/0xa0
enable_trace_kprobe.part.0+0x2e/0x80
kprobe_register+0x6f/0xc0
perf_trace_event_init+0x16b/0x270
perf_kprobe_init+0xa7/0xe0
perf_kprobe_event_init+0x3e/0x70
perf_try_init_event+0x4a/0x140
perf_event_alloc+0x93a/0xde0
__do_sys_perf_event_open+0x19f/0xf30
__x64_sys_perf_event_open+0x20/0x30
do_syscall_64+0x65/0x1d0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #0 (text_mutex){+.+.}:
__lock_acquire+0xfcb/0x1b60
lock_acquire+0xca/0x1d0
__mutex_lock+0xac/0x9f0
mutex_lock_nested+0x1b/0x20
kprobe_optimizer+0x163/0x290
process_one_work+0x22b/0x560
worker_thread+0x50/0x3c0
kthread+0x112/0x150
ret_from_fork+0x3a/0x50
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(module_mutex);
lock(text_mutex);
lock(module_mutex);
lock(text_mutex);
*** DEADLOCK ***
As a reproducer I've been using bcc's funccount.py
(https://github.com/iovisor/bcc/blob/master/tools/funccount.py),
for example:
# ./funccount.py '*interrupt*'
That immediately triggers the lockdep splat.
Fix by acquiring text_mutex before module_mutex in kprobe_optimizer().
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: d5b844a2cf ("ftrace/x86: Remove possible deadlock between register_kprobe() and ftrace_run_update_code()")
Link: http://lkml.kernel.org/r/20190812184302.GA7010@xps-13
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If a task is PI-blocked (blocking on sleeping spinlock) then we don't want to
schedule a new kworker if we schedule out due to lock contention because !RT
does not do that as well. A spinning spinlock disables preemption and a worker
does not schedule out on lock contention (but spin).
On RT the RW-semaphore implementation uses an rtmutex so
tsk_is_pi_blocked() will return true if a task blocks on it. In this case we
will now start a new worker which may deadlock if one worker is waiting on
progress from another worker. Since a RW-semaphore starts a new worker on !RT,
we should do the same on RT.
XFS is able to trigger this deadlock.
Allow to schedule new worker if the current worker is PI-blocked.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20190816160626.12742-1-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Here are 4 small SPDX fixes for 5.3-rc5. A few style fixes for some
SPDX comments, added an SPDX tag for one file, and fix up some GPL
boilerplate for another file.
All of these have been in linux-next for a few weeks with no reported
issues (they are comment changes only, so that's to be expected...)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx
Pull SPDX fixes from Greg KH:
"Here are four small SPDX fixes for 5.3-rc5.
A few style fixes for some SPDX comments, added an SPDX tag for one
file, and fix up some GPL boilerplate for another file.
All of these have been in linux-next for a few weeks with no reported
issues (they are comment changes only, so that's to be expected...)"
* tag 'spdx-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx:
i2c: stm32: Use the correct style for SPDX License Identifier
intel_th: Use the correct style for SPDX License Identifier
coccinelle: api/atomic_as_refcounter: add SPDX License Identifier
kernel/configs: Replace GPL boilerplate code with SPDX identifier
The XSKMAP did not honor the BPF_EXIST/BPF_NOEXIST flags when updating
an entry. This patch addresses that.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
When an AF_XDP socket is released/closed the XSKMAP still holds a
reference to the socket in a "released" state. The socket will still
use the netdev queue resource, and block newly created sockets from
attaching to that queue, but no user application can access the
fill/complete/rx/tx queues. This results in that all applications need
to explicitly clear the map entry from the old "zombie state"
socket. This should be done automatically.
In this patch, the sockets tracks, and have a reference to, which maps
it resides in. When the socket is released, it will remove itself from
all maps.
Suggested-by: Bruce Richardson <bruce.richardson@intel.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Rename existing bpf_map_inc_not_zero to __bpf_map_inc_not_zero to
indicate that it's caller's responsibility to do proper locking.
Create and export bpf_map_inc_not_zero wrapper that properly
locks map_idr_lock. Will be used in the next commit to
hold a map while cloning a socket.
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
- Disable NVMe power optimization related to suspend-to-idle added
recently on systems where PCIe ASPM is not able to put PCIe links
into low-power states to prevent excess power from being drawn by
the system while suspended (Rafael Wysocki).
- Make the schedutil governor handle frequency limits changes
properly in all cases (Viresh Kumar).
- Prevent the cpufreq core from treating positive values returned
by dev_pm_qos_update_request() as errors (Viresh Kumar).
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Merge tag 'pm-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These add a check to avoid recent suspend-to-idle power regression on
systems with NVMe drives where the PCIe ASPM policy is "performance"
(or when the kernel is built without ASPM support), fix an issue
related to frequency limits in the schedutil cpufreq governor and fix
a mistake related to the PM QoS usage in the cpufreq core introduced
recently.
Specifics:
- Disable NVMe power optimization related to suspend-to-idle added
recently on systems where PCIe ASPM is not able to put PCIe links
into low-power states to prevent excess power from being drawn by
the system while suspended (Rafael Wysocki).
- Make the schedutil governor handle frequency limits changes
properly in all cases (Viresh Kumar).
- Prevent the cpufreq core from treating positive values returned by
dev_pm_qos_update_request() as errors (Viresh Kumar)"
* tag 'pm-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
nvme-pci: Allow PCI bus-level PM to be used if ASPM is disabled
PCI/ASPM: Add pcie_aspm_enabled()
cpufreq: schedutil: Don't skip freq update when limits change
cpufreq: dev_pm_qos_update_request() can return 1 on success
Use str_has_prefix() instead of strncmp() which is less
straightforward in decode_state().
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
strncmp(str, const, len) is error-prone because len is easy to have typo.
An example is the hard-coded len has counting error or sizeof(const)
forgets - 1.
So we prefer using newly introduced str_has_prefix() to substitute
such strncmp() to make code better.
Link: http://lkml.kernel.org/r/20190809071034.17279-1-hslester96@gmail.com
Cc: "Steven Rostedt" <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
[pmladek@suse.com: Slightly updated and reformatted the commit message.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
In case of error, the function kobject_create_and_add() returns NULL
pointer not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.
Fixes: 341dfcf8d7 ("btf: expose BTF info through sysfs")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
- fix the handling of the bus_dma_mask in dma_get_required_mask, which
caused a regression in this merge window (Lucas Stach)
- fix a regression in the handling of DMA_ATTR_NO_KERNEL_MAPPING (me)
- fix dma_mmap_coherent to not cause page attribute mismatches on
coherent architectures like x86 (me)
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Merge tag 'dma-mapping-5.3-4' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fixes from Christoph Hellwig:
- fix the handling of the bus_dma_mask in dma_get_required_mask, which
caused a regression in this merge window (Lucas Stach)
- fix a regression in the handling of DMA_ATTR_NO_KERNEL_MAPPING (me)
- fix dma_mmap_coherent to not cause page attribute mismatches on
coherent architectures like x86 (me)
* tag 'dma-mapping-5.3-4' of git://git.infradead.org/users/hch/dma-mapping:
dma-mapping: fix page attributes for dma_mmap_*
dma-direct: don't truncate dma_required_mask to bus addressing capabilities
dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING
Daniel Borkmann says:
====================
The following pull-request contains BPF updates for your *net-next* tree.
There is a small merge conflict in libbpf (Cc Andrii so he's in the loop
as well):
for (i = 1; i <= btf__get_nr_types(btf); i++) {
t = (struct btf_type *)btf__type_by_id(btf, i);
if (!has_datasec && btf_is_var(t)) {
/* replace VAR with INT */
t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
<<<<<<< HEAD
/*
* using size = 1 is the safest choice, 4 will be too
* big and cause kernel BTF validation failure if
* original variable took less than 4 bytes
*/
t->size = 1;
*(int *)(t+1) = BTF_INT_ENC(0, 0, 8);
} else if (!has_datasec && kind == BTF_KIND_DATASEC) {
=======
t->size = sizeof(int);
*(int *)(t + 1) = BTF_INT_ENC(0, 0, 32);
} else if (!has_datasec && btf_is_datasec(t)) {
>>>>>>> 72ef80b5ee
/* replace DATASEC with STRUCT */
Conflict is between the two commits 1d4126c4e1 ("libbpf: sanitize VAR to
conservative 1-byte INT") and b03bc6853c ("libbpf: convert libbpf code to
use new btf helpers"), so we need to pick the sanitation fixup as well as
use the new btf_is_datasec() helper and the whitespace cleanup. Looks like
the following:
[...]
if (!has_datasec && btf_is_var(t)) {
/* replace VAR with INT */
t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
/*
* using size = 1 is the safest choice, 4 will be too
* big and cause kernel BTF validation failure if
* original variable took less than 4 bytes
*/
t->size = 1;
*(int *)(t + 1) = BTF_INT_ENC(0, 0, 8);
} else if (!has_datasec && btf_is_datasec(t)) {
/* replace DATASEC with STRUCT */
[...]
The main changes are:
1) Addition of core parts of compile once - run everywhere (co-re) effort,
that is, relocation of fields offsets in libbpf as well as exposure of
kernel's own BTF via sysfs and loading through libbpf, from Andrii.
More info on co-re: http://vger.kernel.org/bpfconf2019.html#session-2
and http://vger.kernel.org/lpc-bpf2018.html#session-2
2) Enable passing input flags to the BPF flow dissector to customize parsing
and allowing it to stop early similar to the C based one, from Stanislav.
3) Add a BPF helper function that allows generating SYN cookies from XDP and
tc BPF, from Petar.
4) Add devmap hash-based map type for more flexibility in device lookup for
redirects, from Toke.
5) Improvements to XDP forwarding sample code now utilizing recently enabled
devmap lookups, from Jesper.
6) Add support for reporting the effective cgroup progs in bpftool, from Jakub
and Takshak.
7) Fix reading kernel config from bpftool via /proc/config.gz, from Peter.
8) Fix AF_XDP umem pages mapping for 32 bit architectures, from Ivan.
9) Follow-up to add two more BPF loop tests for the selftest suite, from Alexei.
10) Add perf event output helper also for other skb-based program types, from Allan.
11) Fix a co-re related compilation error in selftests, from Yonghong.
====================
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Bimodal behavior of rcu_do_batch() is not really suited to Google
applications like gfe servers.
When a process with millions of sockets exits, closing all files
queues two rcu callbacks per socket.
This eventually reaches the point where RCU enters an emergency
mode, where rcu_do_batch() do not return until whole queue is flushed.
Each rcu callback lasts at least 70 nsec, so with millions of
elements, we easily spend more than 100 msec without rescheduling.
Goal of this patch is to avoid the infamous message like following
"need_resched set for > 51999388 ns (52 ticks) without schedule"
We dynamically adjust the number of elements we process, instead
of 10 / INFINITE choices, we use a floor of ~1 % of current entries.
If the number is above 1000, we switch to a time based limit of 3 msec
per batch, adjustable with /sys/module/rcutree/parameters/rcu_resched_ns
Signed-off-by: Eric Dumazet <edumazet@google.com>
[ paulmck: Forward-port and remove debug statements. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
When under overload conditions, __call_rcu_nocb_wake() will wake the
no-CBs GP kthread any time the no-CBs CB kthread is asleep or there
are no ready-to-invoke callbacks, but only after a timer delay. If the
no-CBs GP kthread has a ->nocb_bypass_timer pending, the deferred wakeup
from __call_rcu_nocb_wake() is redundant. This commit therefore makes
__call_rcu_nocb_wake() avoid posting the redundant deferred wakeup if
->nocb_bypass_timer is pending. This requires adding a bit of ordering
of timer actions.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, __call_rcu_nocb_wake() advances callbacks each time that it
detects excessive numbers of callbacks, though only if it succeeds in
conditionally acquiring its leaf rcu_node structure's ->lock. Despite
the conditional acquisition of ->lock, this does increase contention.
This commit therefore avoids advancing callbacks unless there are
callbacks in ->cblist whose grace period has completed and advancing
has not yet been done during this jiffy.
Note that this decision does not take the presence of new callbacks
into account. That is because on this code path, there will always be
at least one new callback, namely the one we just enqueued.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, nocb_cb_wait() advances callbacks on each pass through its
loop, though only if it succeeds in conditionally acquiring its leaf
rcu_node structure's ->lock. Despite the conditional acquisition of
->lock, this does increase contention. This commit therefore avoids
advancing callbacks unless there are callbacks in ->cblist whose grace
period has completed.
Note that nocb_cb_wait() doesn't worry about callbacks that have not
yet been assigned a grace period. The idea is that the only reason for
nocb_cb_wait() to advance callbacks is to allow it to continue invoking
callbacks. Time will tell whether this is the correct choice.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
The rcutree_migrate_callbacks() invokes rcu_advance_cbs() on both the
offlined CPU's ->cblist and that of the surviving CPU, then merges
them. However, after the merge, and of the offlined CPU's callbacks
that were not ready to be invoked will no longer be associated with a
grace-period number. This commit therefore invokes rcu_advance_cbs()
one more time on the merged ->cblist in order to assign a grace-period
number to these callbacks.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
When callbacks are in full flow, the common case is waiting for a
grace period, and this grace period will normally take a few jiffies to
complete. It therefore isn't all that helpful for __call_rcu_nocb_wake()
to do a synchronous wakeup in this case. This commit therefore turns this
into a timer-based deferred wakeup of the no-CBs grace-period kthread.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit causes locking, sleeping, and callback state to be printed
for no-CBs CPUs when the rcutorture writer is delayed sufficiently for
rcutorture to complain.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Use of the rcu_data structure's segmented ->cblist for no-CBs CPUs
takes advantage of unrelated grace periods, thus reducing the memory
footprint in the face of floods of call_rcu() invocations. However,
the ->cblist field is a more-complex rcu_segcblist structure which must
be protected via locking. Even though there are only three entities
which can acquire this lock (the CPU invoking call_rcu(), the no-CBs
grace-period kthread, and the no-CBs callbacks kthread), the contention
on this lock is excessive under heavy stress.
This commit therefore greatly reduces contention by provisioning
an rcu_cblist structure field named ->nocb_bypass within the
rcu_data structure. Each no-CBs CPU is permitted only a limited
number of enqueues onto the ->cblist per jiffy, controlled by a new
nocb_nobypass_lim_per_jiffy kernel boot parameter that defaults to
about 16 enqueues per millisecond (16 * 1000 / HZ). When that limit is
exceeded, the CPU instead enqueues onto the new ->nocb_bypass.
The ->nocb_bypass is flushed into the ->cblist every jiffy or when
the number of callbacks on ->nocb_bypass exceeds qhimark, whichever
happens first. During call_rcu() floods, this flushing is carried out
by the CPU during the course of its call_rcu() invocations. However,
a CPU could simply stop invoking call_rcu() at any time. The no-CBs
grace-period kthread therefore carries out less-aggressive flushing
(every few jiffies or when the number of callbacks on ->nocb_bypass
exceeds (2 * qhimark), whichever comes first). This means that the
no-CBs grace-period kthread cannot be permitted to do unbounded waits
while there are callbacks on ->nocb_bypass. A ->nocb_bypass_timer is
used to provide the needed wakeups.
[ paulmck: Apply Coverity feedback reported by Colin Ian King. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Upcoming ->nocb_lock contention-reduction work requires that the
rcu_segcblist structure's ->len field be concurrently manipulated,
but only if there are no-CBs CPUs in the kernel. This commit
therefore makes this ->len field be an atomic_long_t, but only
in CONFIG_RCU_NOCB_CPU=y kernels.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
When there are excessive numbers of callbacks, and when either the
corresponding no-CBs callback kthread is asleep or there is no more
ready-to-invoke callbacks, and when least one callback is pending,
__call_rcu_nocb_wake() will advance the callbacks, but refrain from
awakening the corresponding no-CBs grace-period kthread. However,
because rcu_advance_cbs_nowake() is used, it is possible (if a bit
unlikely) that the needed advancement could not happen due to a grace
period not being in progress. Plus there will always be at least one
pending callback due to one having just now been enqueued.
This commit therefore attempts to advance callbacks and awakens the
no-CBs grace-period kthread when there are excessive numbers of callbacks
posted and when the no-CBs callback kthread is not in a position to do
anything helpful.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
The sleep/wakeup of the no-CBs grace-period kthreads is synchronized
using the ->nocb_lock of the first CPU corresponding to that kthread.
This commit provides a separate ->nocb_gp_lock for this purpose, thus
reducing contention on ->nocb_lock.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, nocb_cb_wait() unconditionally acquires the leaf rcu_node
->lock to advance callbacks when done invoking the previous batch.
It does this while holding ->nocb_lock, which means that contention on
the leaf rcu_node ->lock visits itself on the ->nocb_lock. This commit
therefore makes this lock acquisition conditional, forgoing callback
advancement when the leaf rcu_node ->lock is not immediately available.
(In this case, the no-CBs grace-period kthread will eventually do any
needed callback advancement.)
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, __call_rcu_nocb_wake() conditionally acquires the leaf rcu_node
structure's ->lock, and only afterwards does rcu_advance_cbs_nowake()
check to see if it is possible to advance callbacks without potentially
needing to awaken the grace-period kthread. Given that the no-awaken
check can be done locklessly, this commit reverses the order, so that
rcu_advance_cbs_nowake() is invoked without holding the leaf rcu_node
structure's ->lock and rcu_advance_cbs_nowake() checks the grace-period
state before conditionally acquiring that lock, thus reducing the number
of needless acquistions of the leaf rcu_node structure's ->lock.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, when the square root of the number of CPUs is rounded down
by int_sqrt(), this round-down is applied to the number of callback
kthreads per grace-period kthreads. This makes almost no difference
for large systems, but results in oddities such as three no-CBs
grace-period kthreads for a five-CPU system, which is a bit excessive.
This commit therefore causes the round-down to apply to the number of
no-CBs grace-period kthreads, so that systems with from four to eight
CPUs have only two no-CBs grace period kthreads.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
A given rcu_data structure's ->nocb_lock can be acquired very frequently
by the corresponding CPU and occasionally by the corresponding no-CBs
grace-period and callbacks kthreads. In particular, these two kthreads
will have frequent gaps between ->nocb_lock acquisitions that are roughly
a grace period in duration. This means that any excessive ->nocb_lock
contention will be due to the CPU's acquisitions, and this in turn
enables a very naive contention-avoidance strategy to be quite effective.
This commit therefore modifies rcu_nocb_lock() to first
attempt a raw_spin_trylock(), and to atomically increment a
separate ->nocb_lock_contended across a raw_spin_lock(). This new
->nocb_lock_contended field is checked in __call_rcu_nocb_wake() when
interrupts are enabled, with a spin-wait for contending acquisitions
to complete, thus allowing the kthreads a chance to acquire the lock.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, the code provides an extra wakeup for the no-CBs grace-period
kthread if one of its CPUs is generating excessive numbers of callbacks.
But satisfying though it is to wake something up when things are going
south, unless the thing being awakened can actually help solve the
problem, that extra wakeup does nothing but consume additional CPU time,
which is exactly what you don't want during a call_rcu() flood.
This commit therefore avoids doing anything if the corresponding
no-CBs callback kthread is going full tilt. Otherwise, if advancing
callbacks immediately might help and if the leaf rcu_node structure's
lock is immediately available, this commit invokes a new variant of
rcu_advance_cbs() that advances callbacks only if doing so won't require
awakening the grace-period kthread (not to be confused with any of the
no-CBs grace-period kthreads).
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
It might be hard to imagine having more than two billion callbacks
queued on a single CPU's ->cblist, but someone will do it sometime.
This commit therefore makes __call_rcu_nocb_wake() handle this situation
by upgrading local variable "len" from "int" to "long".
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, wake_nocb_gp_defer() simply stores whatever waketype was
passed in, which can result in a RCU_NOCB_WAKE_FORCE being downgraded
to RCU_NOCB_WAKE, which could in turn delay callback processing.
This commit therefore adds a check so that wake_nocb_gp_defer() only
updates ->nocb_defer_wakeup when the update increases the forcefulness,
thus avoiding downgrades.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
The __call_rcu_nocb_wake() function and its predecessors set
->qlen_last_fqs_check to zero for the first callback and to LONG_MAX / 2
for forced reawakenings. The former can result in a too-quick reawakening
when there are many callbacks ready to invoke and the latter prevents a
second reawakening. This commit therefore sets ->qlen_last_fqs_check
to the current number of callbacks in both cases. While in the area,
this commit also moves both assignments under ->nocb_lock.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Historically, no-CBs CPUs allowed the scheduler-clock tick to be
unconditionally disabled on any transition to idle or nohz_full userspace
execution (see the rcu_needs_cpu() implementations). Unfortunately,
the checks used by rcu_needs_cpu() are defeated now that no-CBs CPUs
use ->cblist, which might make users of battery-powered devices rather
unhappy. This commit therefore adds explicit rcu_segcblist_is_offloaded()
checks to return to the historical energy-efficient semantics.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Some compilers complain that wait_gp_seq might be used uninitialized
in nocb_gp_wait(). This cannot actually happen because when wait_gp_seq
is uninitialized, needwait_gp must be false, which prevents wait_gp_seq
from being used. But this analysis is apparently beyond some compilers,
so this commit adds a bogus initialization of wait_gp_seq for the sole
purpose of suppressing the false-positive warning.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, rcu_pending() invokes rcu_segcblist_is_offloaded() even
in CONFIG_RCU_NOCB_CPU=n kernels, which cannot possibly be offloaded.
Given that rcu_pending() is on a fastpath, it makes sense to check for
CONFIG_RCU_NOCB_CPU=y before invoking rcu_segcblist_is_offloaded().
This commit therefore makes this change.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, rcu_core() invokes rcu_segcblist_is_offloaded() each time it
needs to know whether the current CPU is a no-CBs CPU. Given that it is
not possible to change the no-CBs status of a CPU after boot, and given
that it is not possible to even have no-CBs CPUs in CONFIG_RCU_NOCB_CPU=n
kernels, this repeated runtime invocation wastes CPU. This commit
therefore created a const on-stack variable to allow this check to be
done only once per rcu_core() invocation.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, rcu_do_batch() invokes rcu_segcblist_is_offloaded() each time
it needs to know whether the current CPU is a no-CBs CPU. Given that it
is not possible to change the no-CBs status of a CPU after boot, and given
that it is not possible to even have no-CBs CPUs in CONFIG_RCU_NOCB_CPU=n
kernels, this per-callback invocation wastes CPU. This commit therefore
created a const on-stack variable to allow this check to be done only
once per rcu_do_batch() invocation.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit removes the obsolete nocb_q_count and nocb_q_count_lazy
fields, also removing rcu_get_n_cbs_nocb_cpu(), adjusting
rcu_get_n_cbs_cpu(), and making rcutree_migrate_callbacks() once again
disable the ->cblist fields of offline CPUs.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently the RCU callbacks for no-CBs CPUs are queued on a series of
ad-hoc linked lists, which means that these callbacks cannot benefit
from "drive-by" grace periods, thus suffering needless delays prior
to invocation. In addition, the no-CBs grace-period kthreads first
wait for callbacks to appear and later wait for a new grace period,
which means that callbacks appearing during a grace-period wait can
be delayed. These delays increase memory footprint, and could even
result in an out-of-memory condition.
This commit therefore enqueues RCU callbacks from no-CBs CPUs on the
rcu_segcblist structure that is already used by non-no-CBs CPUs. It also
restructures the no-CBs grace-period kthread to be checking for incoming
callbacks while waiting for grace periods. Also, instead of waiting
for a new grace period, it waits for the closest grace period that will
cause some of the callbacks to be safe to invoke. All of these changes
reduce callback latency and thus the number of outstanding callbacks,
in turn reducing the probability of an out-of-memory condition.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
As a first step towards making no-CBs CPUs use the ->cblist, this commit
leaves the ->cblist enabled for these CPUs. The main reason to make
no-CBs CPUs use ->cblist is to take advantage of callback numbering,
which will reduce the effects of missed grace periods which in turn will
reduce forward-progress problems for no-CBs CPUs.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, rcu_segcblist_empty() assumes that the callback list is not
being changed by other CPUs, but upcoming changes will require it to
operate locklessly. This commit therefore adds the needed READ_ONCE()
call, along with the WRITE_ONCE() calls when updating the callback list's
->head field.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, rcu_segcblist_restempty() assumes that the callback list
is not being changed by other CPUs, but upcoming changes will require
it to operate locklessly. This commit therefore adds the needed
READ_ONCE() calls, along with the WRITE_ONCE() calls when updating
the callback list.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
The idea behind the checks for extended quiescent states at the end of
__call_rcu_nocb() is to handle cases where call_rcu() is invoked directly
from within an extended quiescent state, for example, from the idle loop.
However, this will result in a timer-mediated deferred wakeup, which
will cause the needed wakeup to happen within a jiffy or thereabouts.
There should be no forward-progress concerns, and if there are, the proper
response is to exit the extended quiescent state while executing the
endless blast of call_rcu() invocations, for example, using RCU_NONIDLE().
Given the more realistic case of an isolated call_rcu() invocation, there
should be no problem.
This commit therefore removes the checks for invoking call_rcu() within
an extended quiescent state for on no-CBs CPUs.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
In theory, a timer is used to defer wakeups of no-CBs grace-period
kthreads when the wakeup cannot be done safely directly from the
call_rcu(). In practice, the one-jiffy delay is not always consistent
with timely callback invocation under heavy call_rcu() loads. Therefore,
there are a number of checks for a pending deferred wakeup, including
from the scheduling-clock interrupt. Unfortunately, this check follows
the rcu_nohz_full_cpu() early exit, which renders it useless on such CPUs.
This commit therefore moves the check for the pending deferred no-CB
wakeup to precede the rcu_nohz_full_cpu() early exit.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Because rcutree_migrate_callbacks() is invoked infrequently and because
an exact snapshot of the grace-period state might save some callbacks a
second trip through a grace period, this function has used the root
rcu_node structure. However, this safe-second-trip optimization
happens only if rcutree_migrate_callbacks() races with grace-period
initialization, so it is not worth the added mental load. This commit
therefore makes rcutree_migrate_callbacks() start with the leaf rcu_node
structures, as is done elsewhere.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit is a preparatory patch for offloaded callbacks using the
same ->cblist structure used by non-offloaded callbacks. It therefore
adds rcu_segcblist_is_offloaded() calls where they will be needed when
!rcu_segcblist_is_enabled() no longer flags the offloaded case. It also
adds checks in rcu_do_batch() to ensure that there are no missed checks:
Currently, it should not be possible for offloaded execution to reach
rcu_do_batch(), though this will change later in this series.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
RCU callback processing currently uses rcu_is_nocb_cpu() to determine
whether or not the current CPU's callbacks are to be offloaded.
This works, but it is not so good for cache locality. Plus use of
->cblist for offloaded callbacks will greatly increase the frequency
of these checks. This commit therefore adds a ->offloaded flag to the
rcu_segcblist structure to provide a more flexible and cache-friendly
means of checking for callback offloading.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
NULLing the RCU_NEXT_TAIL pointer was a clever way to save a byte, but
forward-progress considerations would require that this pointer be both
NULL and non-NULL, which, absent a quantum-computer port of the Linux
kernel, simply won't happen. This commit therefore creates as separate
->enabled flag to replace the current NULL checks.
[ paulmck: Add include files per 0day test robot and -next. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit causes the no-CBs grace-period/callback hierarchy to be
printed to the console when the dump_tree kernel boot parameter is set.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit changes the name of the rcu_nocb_leader_stride kernel
boot parameter to rcu_nocb_gp_stride in order to account for the new
distinction between callback and grace-period no-CBs kthreads.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
The nocb_cb_wait() function traces a "FollowerSleep" trace_rcu_nocb_wake()
event, which never was documented and is now misleading. This commit
therefore changes "FollowerSleep" to "CBSleep", documents this, and
updates the documentation for "Sleep" as well.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit renames rdp_leader to rdp_gp in order to account for the
new distinction between callback and grace-period no-CBs kthreads.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit adjusts naming to account for the new distinction between
callback and grace-period no-CBs kthreads.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit adjusts naming to account for the new distinction between
callback and grace-period no-CBs kthreads. While in the area, it also
updates local variables.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit adjusts naming to account for the new distinction between
callback and grace-period no-CBs kthreads.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit adjusts naming to account for the new distinction between
callback and grace-period no-CBs kthreads.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Currently, there is one no-CBs rcuo kthread per CPU, and these kthreads
are divided into groups. The first rcuo kthread to come online in a
given group is that group's leader, and the leader both waits for grace
periods and invokes its CPU's callbacks. The non-leader rcuo kthreads
only invoke callbacks.
This works well in the real-time/embedded environments for which it was
intended because such environments tend not to generate all that many
callbacks. However, given huge floods of callbacks, it is possible for
the leader kthread to be stuck invoking callbacks while its followers
wait helplessly while their callbacks pile up. This is a good recipe
for an OOM, and rcutorture's new callback-flood capability does generate
such OOMs.
One strategy would be to wait until such OOMs start happening in
production, but similar OOMs have in fact happened starting in 2018.
It would therefore be wise to take a more proactive approach.
This commit therefore features per-CPU rcuo kthreads that do nothing
but invoke callbacks. Instead of having one of these kthreads act as
leader, each group has a separate rcog kthread that handles grace periods
for its group. Because these rcuog kthreads do not invoke callbacks,
callback floods on one CPU no longer block callbacks from reaching the
rcuc callback-invocation kthreads on other CPUs.
This change does introduce additional kthreads, however:
1. The number of additional kthreads is about the square root of
the number of CPUs, so that a 4096-CPU system would have only
about 64 additional kthreads. Note that recent changes
decreased the number of rcuo kthreads by a factor of two
(CONFIG_PREEMPT=n) or even three (CONFIG_PREEMPT=y), so
this still represents a significant improvement on most systems.
2. The leading "rcuo" of the rcuog kthreads should allow existing
scripting to affinity these additional kthreads as needed, the
same as for the rcuop and rcuos kthreads. (There are no longer
any rcuob kthreads.)
3. A state-machine approach was considered and rejected. Although
this would allow the rcuo kthreads to continue their dual
leader/follower roles, it complicates callback invocation
and makes it more difficult to consolidate rcuo callback
invocation with existing softirq callback invocation.
The introduction of rcuog kthreads should thus be acceptable.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit simply rewords comments to prepare for leader nocb kthreads
doing only grace-period work and callback shuffling. This will mean
the addition of replacement kthreads to invoke callbacks. The "leader"
and "follower" thus become less meaningful, so the commit changes no-CB
comments with these strings to "GP" and "CB", respectively. (Give or
take the usual grammatical transformations.)
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
This commit simply renames rcu_data fields to prepare for leader
nocb kthreads doing only grace-period work and callback shuffling.
This will mean the addition of replacement kthreads to invoke callbacks.
The "leader" and "follower" thus become less meaningful, so the commit
changes no-CB fields with these strings to "gp" and "cb", respectively.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Expose kernel's BTF under the name vmlinux to be more uniform with using
kernel module names as file names in the future.
Fixes: 341dfcf8d7 ("btf: expose BTF info through sysfs")
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Make .BTF section allocated and expose its contents through sysfs.
/sys/kernel/btf directory is created to contain all the BTFs present
inside kernel. Currently there is only kernel's main BTF, represented as
/sys/kernel/btf/kernel file. Once kernel modules' BTFs are supported,
each module will expose its BTF as /sys/kernel/btf/<module-name> file.
Current approach relies on a few pieces coming together:
1. pahole is used to take almost final vmlinux image (modulo .BTF and
kallsyms) and generate .BTF section by converting DWARF info into
BTF. This section is not allocated and not mapped to any segment,
though, so is not yet accessible from inside kernel at runtime.
2. objcopy dumps .BTF contents into binary file and subsequently
convert binary file into linkable object file with automatically
generated symbols _binary__btf_kernel_bin_start and
_binary__btf_kernel_bin_end, pointing to start and end, respectively,
of BTF raw data.
3. final vmlinux image is generated by linking this object file (and
kallsyms, if necessary). sysfs_btf.c then creates
/sys/kernel/btf/kernel file and exposes embedded BTF contents through
it. This allows, e.g., libbpf and bpftool access BTF info at
well-known location, without resorting to searching for vmlinux image
on disk (location of which is not standardized and vmlinux image
might not be even available in some scenarios, e.g., inside qemu
during testing).
Alternative approach using .incbin assembler directive to embed BTF
contents directly was attempted but didn't work, because sysfs_proc.o is
not re-compiled during link-vmlinux.sh stage. This is required, though,
to update embedded BTF data (initially empty data is embedded, then
pahole generates BTF info and we need to regenerate sysfs_btf.o with
updated contents, but it's too late at that point).
If BTF couldn't be generated due to missing or too old pahole,
sysfs_btf.c handles that gracefully by detecting that
_binary__btf_kernel_bin_start (weak symbol) is 0 and not creating
/sys/kernel/btf at all.
v2->v3:
- added Documentation/ABI/testing/sysfs-kernel-btf (Greg K-H);
- created proper kobject (btf_kobj) for btf directory (Greg K-H);
- undo v2 change of reusing vmlinux, as it causes extra kallsyms pass
due to initially missing __binary__btf_kernel_bin_{start/end} symbols;
v1->v2:
- allow kallsyms stage to re-use vmlinux generated by gen_btf();
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit fixes a spelling mistake in file tree_exp.h.
Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Because rcu_expedited_nesting is initialized to 1 and not decremented
until just before init is spawned, rcu_expedited_nesting is guaranteed
to be non-zero whenever rcu_scheduler_active == RCU_SCHEDULER_INIT.
This commit therefore removes this redundant "if" equality test.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Scheduling-clock interrupts can arrive late in the CPU-offline process,
after idle entry and the subsequent call to cpuhp_report_idle_dead().
Once execution passes the call to rcu_report_dead(), RCU is ignoring
the CPU, which results in lockdep complaints when the interrupt handler
uses RCU:
------------------------------------------------------------------------
=============================
WARNING: suspicious RCU usage
5.2.0-rc1+ #681 Not tainted
-----------------------------
kernel/sched/fair.c:9542 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
RCU used illegally from offline CPU!
rcu_scheduler_active = 2, debug_locks = 1
no locks held by swapper/5/0.
stack backtrace:
CPU: 5 PID: 0 Comm: swapper/5 Not tainted 5.2.0-rc1+ #681
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Bochs 01/01/2011
Call Trace:
<IRQ>
dump_stack+0x5e/0x8b
trigger_load_balance+0xa8/0x390
? tick_sched_do_timer+0x60/0x60
update_process_times+0x3b/0x50
tick_sched_handle+0x2f/0x40
tick_sched_timer+0x32/0x70
__hrtimer_run_queues+0xd3/0x3b0
hrtimer_interrupt+0x11d/0x270
? sched_clock_local+0xc/0x74
smp_apic_timer_interrupt+0x79/0x200
apic_timer_interrupt+0xf/0x20
</IRQ>
RIP: 0010:delay_tsc+0x22/0x50
Code: ff 0f 1f 80 00 00 00 00 65 44 8b 05 18 a7 11 48 0f ae e8 0f 31 48 89 d6 48 c1 e6 20 48 09 c6 eb 0e f3 90 65 8b 05 fe a6 11 48 <41> 39 c0 75 18 0f ae e8 0f 31 48 c1 e2 20 48 09 c2 48 89 d0 48 29
RSP: 0000:ffff8f92c0157ed0 EFLAGS: 00000212 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000005 RBX: ffff8c861f356400 RCX: ffff8f92c0157e64
RDX: 000000321214c8cc RSI: 00000032120daa7f RDI: 0000000000260f15
RBP: 0000000000000005 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8c861ee18000 R15: ffff8c861ee18000
cpuhp_report_idle_dead+0x31/0x60
do_idle+0x1d5/0x200
? _raw_spin_unlock_irqrestore+0x2d/0x40
cpu_startup_entry+0x14/0x20
start_secondary+0x151/0x170
secondary_startup_64+0xa4/0xb0
------------------------------------------------------------------------
This happens rarely, but can be forced by happen more often by
placing delays in cpuhp_report_idle_dead() following the call to
rcu_report_dead(). With this in place, the following rcutorture
scenario reproduces the problem within a few minutes:
tools/testing/selftests/rcutorture/bin/kvm.sh --cpus 8 --duration 5 --kconfig "CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y" --configs "TREE04"
This commit uses the crude but effective expedient of moving the disabling
of interrupts within the idle loop to precede the cpu_is_offline()
check. It also invokes tick_nohz_idle_stop_tick() instead of
tick_nohz_idle_stop_tick_protected() to shut off the scheduling-clock
interrupt.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
[ paulmck: Revert tick_nohz_idle_stop_tick_protected() removal, new callers. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
If CONFIG_ARCH_TASK_STRUCT_ALLOCATOR is set task_struct_whitelist is
never called, and thus generates a compiler warning.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lkml.kernel.org/r/20190812065524.19959-5-hch@lst.de
Signed-off-by: Tony Luck <tony.luck@intel.com>
Enabling WARN_DOUBLE_CLOCK in /sys/kernel/debug/sched_features causes
warning to fire in update_rq_clock. This seems to be caused by onlining
a new fair sched group not using the rq lock wrappers.
[] rq->clock_update_flags & RQCF_UPDATED
[] WARNING: CPU: 5 PID: 54385 at kernel/sched/core.c:210 update_rq_clock+0xec/0x150
[] Call Trace:
[] online_fair_sched_group+0x53/0x100
[] cpu_cgroup_css_online+0x16/0x20
[] online_css+0x1c/0x60
[] cgroup_apply_control_enable+0x231/0x3b0
[] cgroup_mkdir+0x41b/0x530
[] kernfs_iop_mkdir+0x61/0xa0
[] vfs_mkdir+0x108/0x1a0
[] do_mkdirat+0x77/0xe0
[] do_syscall_64+0x55/0x1d0
[] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Using the wrappers in online_fair_sched_group instead of the raw locking
removes this warning.
[ tglx: Use rq_*lock_irq() ]
Signed-off-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20190801133749.11033-1-pauld@redhat.com
Pull scheduler fixes from Thomas Gleixner:
"Three fixlets for the scheduler:
- Avoid double bandwidth accounting in the push & pull code
- Use a sane FIFO priority for the Pressure Stall Information (PSI)
thread.
- Avoid permission checks when setting the scheduler params for the
PSI thread"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/psi: Do not require setsched permission from the trigger creator
sched/psi: Reduce psimon FIFO priority
sched/deadline: Fix double accounting of rq/running bw in push & pull
All the way back to introducing dma_common_mmap we've defaulted to mark
the pages as uncached. But this is wrong for DMA coherent devices.
Later on DMA_ATTR_WRITE_COMBINE also got incorrect treatment as that
flag is only treated special on the alloc side for non-coherent devices.
Introduce a new dma_pgprot helper that deals with the check for coherent
devices so that only the remapping cases ever reach arch_dma_mmap_pgprot
and we thus ensure no aliasing of page attributes happens, which makes
the powerpc version of arch_dma_mmap_pgprot obsolete and simplifies the
remaining ones.
Note that this means arch_dma_mmap_pgprot is a bit misnamed now, but
we'll phase it out soon.
Fixes: 64ccc9c033 ("common: dma-mapping: add support for generic dma_mmap_* calls")
Reported-by: Shawn Anastasio <shawn@anastas.io>
Reported-by: Gavin Li <git@thegavinli.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> # arm64
The dma required_mask needs to reflect the actual addressing capabilities
needed to handle the whole system RAM. When truncated down to the bus
addressing capabilities dma_addressing_limited() will incorrectly signal
no limitations for devices which are restricted by the bus_dma_mask.
Fixes: b4ebe60632 (dma-direct: implement complete bus_dma_mask handling)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The new DMA_ATTR_NO_KERNEL_MAPPING needs to actually assign
a dma_addr to work. Also skip it if the architecture needs
forced decryption handling, as that needs a kernel virtual
address.
Fixes: d98849aff8 (dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
To avoid reducing the frequency of a CPU prematurely, we skip reducing
the frequency if the CPU had been busy recently.
This should not be done when the limits of the policy are changed, for
example due to thermal throttling. We should always get the frequency
within the new limits as soon as possible.
Trying to fix this by using only one flag, i.e. need_freq_update, can
lead to a race condition where the flag gets cleared without forcing us
to change the frequency at least once. And so this patch introduces
another flag to avoid that race condition.
Fixes: ecd2884291 ("cpufreq: schedutil: Don't set next_freq to UINT_MAX")
Cc: v4.18+ <stable@vger.kernel.org> # v4.18+
Reported-by: Doug Smythies <dsmythies@telus.net>
Tested-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
After commit ac9eafbe93 ("ACPI: PM: s2idle: Execute LPS0 _DSM
functions with suspended devices"), a NULL pointer may be dereferenced
if suspend-to-idle is attempted on a platform without "traditional"
suspend support due to invalid fall-through in
platform_suspend_prepare_noirq().
Fix that and while at it add missing braces in platform_resume_noirq().
Fixes: ac9eafbe93 ("ACPI: PM: s2idle: Execute LPS0 _DSM functions with suspended devices")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit adds RCU-reader checks to list_for_each_entry_rcu() and
hlist_for_each_entry_rcu(). These checks are optional, and are indicated
by a lockdep expression passed to a new optional argument to these two
macros. If this optional lockdep expression is omitted, these two macros
act as before, checking for an RCU read-side critical section.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Update to eliminate return within macro and update comment. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
sme_active() is an x86-specific function so it's better not to call it from
generic code. Christoph Hellwig mentioned that "There is no reason why we
should have a special debug printk just for one specific reason why there
is a requirement for a large DMA mask.", so just remove dma_check_mask().
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190806044919.10622-4-bauerman@linux.ibm.com
sme_active() is an x86-specific function so it's better not to call it from
generic code.
There's no need to mention which memory encryption feature is active, so
just use a more generic message. Besides, other architectures will have
different names for similar technology.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190806044919.10622-3-bauerman@linux.ibm.com
Exercising CPU hotplug on a 5.2 kernel with recent padata fixes from
cryptodev-2.6.git in an 8-CPU kvm guest...
# modprobe tcrypt alg="pcrypt(rfc4106(gcm(aes)))" type=3
# echo 0 > /sys/devices/system/cpu/cpu1/online
# echo c > /sys/kernel/pcrypt/pencrypt/parallel_cpumask
# modprobe tcrypt mode=215
...caused the following crash:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 2 PID: 134 Comm: kworker/2:2 Not tainted 5.2.0-padata-base+ #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-<snip>
Workqueue: pencrypt padata_parallel_worker
RIP: 0010:padata_reorder+0xcb/0x180
...
Call Trace:
padata_do_serial+0x57/0x60
pcrypt_aead_enc+0x3a/0x50 [pcrypt]
padata_parallel_worker+0x9b/0xe0
process_one_work+0x1b5/0x3f0
worker_thread+0x4a/0x3c0
...
In padata_alloc_pd, pd->cpu is set using the user-supplied cpumask
instead of the effective cpumask, and in this case cpumask_first picked
an offline CPU.
The offline CPU's reorder->list.next is NULL in padata_reorder because
the list wasn't initialized in padata_init_pqueues, which only operates
on CPUs in the effective mask.
Fix by using the effective mask in padata_alloc_pd.
Fixes: 6fc4dbcf02 ("padata: Replace delayed timer with immediate workqueue in padata_reorder")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
According to Section 3.5 of the "Intel Low Power S0 Idle" document [1],
Function 5 of the LPS0 _DSM is expected to be invoked when the system
configuration matches the criteria for entering the target low-power
state of the platform. In particular, this means that all devices
should be suspended and in low-power states already when that function
is invoked.
This is not the case currently, however, because Function 5 of the
LPS0 _DSM is invoked by it before the "noirq" phase of device suspend,
which means that some devices may not have been put into low-power
states yet at that point. That is a consequence of the previous
design of the suspend-to-idle flow that allowed the "noirq" phase of
device suspend and the "noirq" phase of device resume to be carried
out for multiple times while "suspended" (if any spurious wakeup
events were detected) and the point of the LPS0 _DSM Function 5
invocation was chosen so as to call it (and LPS0 _DSM Function 6
analogously) once per suspend-resume cycle (regardless of how many
times the "noirq" phases of device suspend and resume were carried
out while "suspended").
Now that the suspend-to-idle flow has been redesigned to carry out
the "noirq" phases of device suspend and resume once in each cycle,
the code can be reordered to follow the specification that it is
based on more closely.
For this purpose, add ->prepare_late and ->restore_early platform
callbacks for suspend-to-idle, to be executed, respectively, after
the "noirq" phase of suspending devices and before the "noirq"
phase of resuming them and make ACPI use them for the invocation
of LPS0 _DSM functions as appropriate.
While at it, move the LPS0 entry requirements check to be made
before invoking Functions 3 and 5 of the LPS0 _DSM (also once
per cycle) as follows from the specification [1].
Link: https://uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf # [1]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
scale_irq_capacity() call in schedutil_cpu_util() does
util *= (max - irq)
util /= max
But the comment says
util *= (1 - irq)
util /= max
Fix the comment to match what the scaling function does.
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net>
Link: https://lkml.kernel.org/r/20190802104628.8410-1-qais.yousef@arm.com
Avoid the RETRY_TASK case in the pick_next_task() slow path.
By doing the put_prev_task() early, we get the rt/deadline pull done,
and by testing rq->nr_running we know if we need newidle_balance().
This then gives a stable state to pick a task from.
Since the fast-path is fair only; it means the other classes will
always have pick_next_task(.prev=NULL, .rf=NULL) and we can simplify.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Aaron Lu <aaron.lwe@gmail.com>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: mingo@kernel.org
Cc: Phil Auld <pauld@redhat.com>
Cc: Julien Desfossez <jdesfossez@digitalocean.com>
Cc: Nishanth Aravamudan <naravamudan@digitalocean.com>
Link: https://lkml.kernel.org/r/aa34d24b36547139248f32a30138791ac6c02bd6.1559129225.git.vpillai@digitalocean.com
Currently the pick_next_task() loop is convoluted and ugly because of
how it can drop the rq->lock and needs to restart the picking.
For the RT/Deadline classes, it is put_prev_task() where we do
balancing, and we could do this before the picking loop. Make this
possible.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Aaron Lu <aaron.lwe@gmail.com>
Cc: mingo@kernel.org
Cc: Phil Auld <pauld@redhat.com>
Cc: Julien Desfossez <jdesfossez@digitalocean.com>
Cc: Nishanth Aravamudan <naravamudan@digitalocean.com>
Link: https://lkml.kernel.org/r/e4519f6850477ab7f3d257062796e6425ee4ba7c.1559129225.git.vpillai@digitalocean.com
For pick_next_task_fair() it is the newidle balance that requires
dropping the rq->lock; provided we do put_prev_task() early, we can
also detect the condition for doing newidle early.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Aaron Lu <aaron.lwe@gmail.com>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: mingo@kernel.org
Cc: Phil Auld <pauld@redhat.com>
Cc: Julien Desfossez <jdesfossez@digitalocean.com>
Cc: Nishanth Aravamudan <naravamudan@digitalocean.com>
Link: https://lkml.kernel.org/r/9e3eb1859b946f03d7e500453a885725b68957ba.1559129225.git.vpillai@digitalocean.com
In preparation of further separating pick_next_task() and
set_curr_task() we have to pass the actual task into it, while there,
rename the thing to better pair with put_prev_task().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Aaron Lu <aaron.lwe@gmail.com>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: mingo@kernel.org
Cc: Phil Auld <pauld@redhat.com>
Cc: Julien Desfossez <jdesfossez@digitalocean.com>
Cc: Nishanth Aravamudan <naravamudan@digitalocean.com>
Link: https://lkml.kernel.org/r/a96d1bcdd716db4a4c5da2fece647a1456c0ed78.1559129225.git.vpillai@digitalocean.com
The CPU hotplug task selection is the only place where we used
put_prev_task() on a task that is not current. While looking at that,
it occured to me that we can simplify all that by by using a custom
pick loop.
Since we don't need to put current, we can do away with the fake task
too.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Aaron Lu <aaron.lwe@gmail.com>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: mingo@kernel.org
Cc: Phil Auld <pauld@redhat.com>
Cc: Julien Desfossez <jdesfossez@digitalocean.com>
Cc: Nishanth Aravamudan <naravamudan@digitalocean.com>
Because pick_next_task() implies set_curr_task() and some of the
details haven't mattered too much, some of what _should_ be in
set_curr_task() ended up in pick_next_task, correct this.
This prepares the way for a pick_next_task() variant that does not
affect the current state; allowing remote picking.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Aaron Lu <aaron.lwe@gmail.com>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: mingo@kernel.org
Cc: Phil Auld <pauld@redhat.com>
Cc: Julien Desfossez <jdesfossez@digitalocean.com>
Cc: Nishanth Aravamudan <naravamudan@digitalocean.com>
Link: https://lkml.kernel.org/r/38c61d5240553e043c27c5e00b9dd0d184dd6081.1559129225.git.vpillai@digitalocean.com
It has been observed, that highly-threaded, non-cpu-bound applications
running under cpu.cfs_quota_us constraints can hit a high percentage of
periods throttled while simultaneously not consuming the allocated
amount of quota. This use case is typical of user-interactive non-cpu
bound applications, such as those running in kubernetes or mesos when
run on multiple cpu cores.
This has been root caused to cpu-local run queue being allocated per cpu
bandwidth slices, and then not fully using that slice within the period.
At which point the slice and quota expires. This expiration of unused
slice results in applications not being able to utilize the quota for
which they are allocated.
The non-expiration of per-cpu slices was recently fixed by
'commit 512ac999d2 ("sched/fair: Fix bandwidth timer clock drift
condition")'. Prior to that it appears that this had been broken since
at least 'commit 51f2176d74 ("sched/fair: Fix unlocked reads of some
cfs_b->quota/period")' which was introduced in v3.16-rc1 in 2014. That
added the following conditional which resulted in slices never being
expired.
if (cfs_rq->runtime_expires != cfs_b->runtime_expires) {
/* extend local deadline, drift is bounded above by 2 ticks */
cfs_rq->runtime_expires += TICK_NSEC;
Because this was broken for nearly 5 years, and has recently been fixed
and is now being noticed by many users running kubernetes
(https://github.com/kubernetes/kubernetes/issues/67577) it is my opinion
that the mechanisms around expiring runtime should be removed
altogether.
This allows quota already allocated to per-cpu run-queues to live longer
than the period boundary. This allows threads on runqueues that do not
use much CPU to continue to use their remaining slice over a longer
period of time than cpu.cfs_period_us. However, this helps prevent the
above condition of hitting throttling while also not fully utilizing
your cpu quota.
This theoretically allows a machine to use slightly more than its
allotted quota in some periods. This overflow would be bounded by the
remaining quota left on each per-cpu runqueueu. This is typically no
more than min_cfs_rq_runtime=1ms per cpu. For CPU bound tasks this will
change nothing, as they should theoretically fully utilize all of their
quota in each period. For user-interactive tasks as described above this
provides a much better user/application experience as their cpu
utilization will more closely match the amount they requested when they
hit throttling. This means that cpu limits no longer strictly apply per
period for non-cpu bound applications, but that they are still accurate
over longer timeframes.
This greatly improves performance of high-thread-count, non-cpu bound
applications with low cfs_quota_us allocation on high-core-count
machines. In the case of an artificial testcase (10ms/100ms of quota on
80 CPU machine), this commit resulted in almost 30x performance
improvement, while still maintaining correct cpu quota restrictions.
That testcase is available at https://github.com/indeedeng/fibtest.
Fixes: 512ac999d2 ("sched/fair: Fix bandwidth timer clock drift condition")
Signed-off-by: Dave Chiluk <chiluk+linux@indeed.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Ben Segall <bsegall@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: John Hammond <jhammond@indeed.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kyle Anderson <kwa@yelp.com>
Cc: Gabriel Munos <gmunoz@netflix.com>
Cc: Peter Oskolkov <posk@posk.io>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Brendan Gregg <bgregg@netflix.com>
Link: https://lkml.kernel.org/r/1563900266-19734-2-git-send-email-chiluk+linux@indeed.com
The current active_mm reference counting is confusing and sub-optimal.
Rewrite the code to explicitly consider the 4 separate cases:
user -> user
When switching between two user tasks, all we need to consider
is switch_mm().
user -> kernel
When switching from a user task to a kernel task (which
doesn't have an associated mm) we retain the last mm in our
active_mm. Increment a reference count on active_mm.
kernel -> kernel
When switching between kernel threads, all we need to do is
pass along the active_mm reference.
kernel -> user
When switching between a kernel and user task, we must switch
from the last active_mm to the next mm, hoping of course that
these are the same. Decrement a reference on the active_mm.
The code keeps a different order, because as you'll note, both 'to
user' cases require switch_mm().
And where the old code would increment/decrement for the 'kernel ->
kernel' case, the new code observes this is a neutral operation and
avoids touching the reference count.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: luto@kernel.org
A rather embarrasing mistake had us call sched_setscheduler() before
initializing the parameters passed to it.
Fixes: 1a763fd7c6 ("rcu/tree: Call setschedule() gp ktread to SCHED_FIFO outside of atomic region")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
The patch moving bits into mutex.c was a little too much; by also
moving struct mutex_waiter a few less common CONFIGs would no longer
build.
Fixes: 5f35d5a66b ("locking/mutex: Make __mutex_owner static to mutex.c")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Since commit c66d4bd110 ("genirq/affinity: Add new callback for
(re)calculating interrupt sets"), irq_create_affinity_masks() returns
NULL in case of single vector. This change has caused regression on some
drivers, such as lpfc.
The problem is that single vector requests can happen in some generic cases:
1) kdump kernel
2) irq vectors resource is close to exhaustion.
If in that situation the affinity mask for a single vector is not created,
every caller has to handle the special case.
There is no reason why the mask cannot be created, so remove the check for
a single vector and create the mask.
Fixes: c66d4bd110 ("genirq/affinity: Add new callback for (re)calculating interrupt sets")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190805011906.5020-1-ming.lei@redhat.com
Instead of using its own logic for k-/vmalloc rely on
kvmalloc which is actually doing quite the same.
Signed-off-by: Marc Koderer <marc@koderer.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Booting a large arm64 server (HiSi D05) leads to the following
shouting at boot time:
[ 20.722132] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
[ 20.730851] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
[ 20.739560] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
[ 20.748267] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
[ 20.756975] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
[ 20.765683] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
[ 20.774391] debugfs: File 'irqchip@(____ptrval____)-3' in directory 'domains' already present!
and many more... Evidently, we expect something a bit more informative
than ____ptrval____, and certainly we want all of our domains, not just
the first one.
For that, turn the %p used to generate the fwnode name into something
that won't be repainted (%pa). Given that we've now fixed all users to
pass a pointer to a PA, it will actually do the right thing.
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Pull networking fixes from David Miller:
"Yeah I should have sent a pull request last week, so there is a lot
more here than usual:
1) Fix memory leak in ebtables compat code, from Wenwen Wang.
2) Several kTLS bug fixes from Jakub Kicinski (circular close on
disconnect etc.)
3) Force slave speed check on link state recovery in bonding 802.3ad
mode, from Thomas Falcon.
4) Clear RX descriptor bits before assigning buffers to them in
stmmac, from Jose Abreu.
5) Several missing of_node_put() calls, mostly wrt. for_each_*() OF
loops, from Nishka Dasgupta.
6) Double kfree_skb() in peak_usb can driver, from Stephane Grosjean.
7) Need to hold sock across skb->destructor invocation, from Cong
Wang.
8) IP header length needs to be validated in ipip tunnel xmit, from
Haishuang Yan.
9) Use after free in ip6 tunnel driver, also from Haishuang Yan.
10) Do not use MSI interrupts on r8169 chips before RTL8168d, from
Heiner Kallweit.
11) Upon bridge device init failure, we need to delete the local fdb.
From Nikolay Aleksandrov.
12) Handle erros from of_get_mac_address() properly in stmmac, from
Martin Blumenstingl.
13) Handle concurrent rename vs. dump in netfilter ipset, from Jozsef
Kadlecsik.
14) Setting NETIF_F_LLTX on mac80211 causes complete breakage with
some devices, so revert. From Johannes Berg.
15) Fix deadlock in rxrpc, from David Howells.
16) Fix Kconfig deps of enetc driver, we must have PHYLIB. From Yue
Haibing.
17) Fix mvpp2 crash on module removal, from Matteo Croce.
18) Fix race in genphy_update_link, from Heiner Kallweit.
19) bpf_xdp_adjust_head() stopped working with generic XDP when we
fixes generic XDP to support stacked devices properly, fix from
Jesper Dangaard Brouer.
20) Unbalanced RCU locking in rt6_update_exception_stamp_rt(), from
David Ahern.
21) Several memory leaks in new sja1105 driver, from Vladimir Oltean"
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (214 commits)
net: dsa: sja1105: Fix memory leak on meta state machine error path
net: dsa: sja1105: Fix memory leak on meta state machine normal path
net: dsa: sja1105: Really fix panic on unregistering PTP clock
net: dsa: sja1105: Use the LOCKEDS bit for SJA1105 E/T as well
net: dsa: sja1105: Fix broken learning with vlan_filtering disabled
net: dsa: qca8k: Add of_node_put() in qca8k_setup_mdio_bus()
net: sched: sample: allow accessing psample_group with rtnl
net: sched: police: allow accessing police->params with rtnl
net: hisilicon: Fix dma_map_single failed on arm64
net: hisilicon: fix hip04-xmit never return TX_BUSY
net: hisilicon: make hip04_tx_reclaim non-reentrant
tc-testing: updated vlan action tests with batch create/delete
net sched: update vlan action for batched events operations
net: stmmac: tc: Do not return a fragment entry
net: stmmac: Fix issues when number of Queues >= 4
net: stmmac: xgmac: Fix XGMAC selftests
be2net: disable bh with spin_lock in be_process_mcc
net: cxgb3_main: Fix a resource leak in a error path in 'init_one()'
net: ethernet: sun4i-emac: Support phy-handle property for finding PHYs
net: bridge: move default pvid init/deinit to NETDEV_REGISTER/UNREGISTER
...
It is not desirable to relax the ABI to allow tagged user addresses into
the kernel indiscriminately. This patch introduces a prctl() interface
for enabling or disabling the tagged ABI with a global sysctl control
for preventing applications from enabling the relaxed ABI (meant for
testing user-space prctl() return error checking without reconfiguring
the kernel). The ABI properties are inherited by threads of the same
application and fork()'ed children but cleared on execve(). A Kconfig
option allows the overall disabling of the relaxed ABI.
The PR_SET_TAGGED_ADDR_CTRL will be expanded in the future to handle
MTE-specific settings like imprecise vs precise exceptions.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
When a process creates a new trigger by writing into /proc/pressure/*
files, permissions to write such a file should be used to determine whether
the process is allowed to do so or not. Current implementation would also
require such a process to have setsched capability. Setting of psi trigger
thread's scheduling policy is an implementation detail and should not be
exposed to the user level. Remove the permission check by using _nocheck
version of the function.
Suggested-by: Nick Kralevich <nnk@google.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: lizefan@huawei.com
Cc: mingo@redhat.com
Cc: akpm@linux-foundation.org
Cc: kernel-team@android.com
Cc: dennisszhou@gmail.com
Cc: dennis@kernel.org
Cc: hannes@cmpxchg.org
Cc: axboe@kernel.dk
Link: https://lkml.kernel.org/r/20190730013310.162367-1-surenb@google.com
PSI defaults to a FIFO-99 thread, reduce this to FIFO-1.
FIFO-99 is the very highest priority available to SCHED_FIFO and
it not a suitable default; it would indicate the psi work is the
most important work on the machine.
Since Real-Time tasks will have pre-allocated memory and locked it in
place, Real-Time tasks do not care about PSI. All it needs is to be
above OTHER.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
__mutex_owner() should only be used by the mutex api's.
So, to put this restiction let's move the __mutex_owner()
function definition from linux/mutex.h to mutex.c file.
There exist functions that uses __mutex_owner() like
mutex_is_locked() and mutex_trylock_recursive(), So
to keep legacy thing intact move them as well and
export them.
Move mutex_waiter structure also to keep it private to the
file.
Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: mingo@redhat.com
Cc: will@kernel.org
Link: https://lkml.kernel.org/r/1564585504-3543-1-git-send-email-mojha@codeaurora.org
Currently rwsems is the only locking primitive that lacks this
debug feature. Add it under CONFIG_DEBUG_RWSEMS and do the magic
checking in the locking fastpath (trylock) operation such that
we cover all cases. The unlocking part is pretty straightforward.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: mingo@kernel.org
Cc: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lkml.kernel.org/r/20190729044735.9632-1-dave@stgolabs.net
When the handoff bit is set by a writer, no other tasks other than
the setting writer itself is allowed to acquire the lock. If the
to-be-handoff'ed writer goes to sleep, there will be a wakeup latency
period where the lock is free, but no one can acquire it. That is less
than ideal.
To reduce that latency, the handoff writer will now optimistically spin
on the owner if it happens to be a on-cpu writer. It will spin until
it releases the lock and the to-be-handoff'ed writer can then acquire
the lock immediately without any delay. Of course, if the owner is not
a on-cpu writer, the to-be-handoff'ed writer will have to sleep anyway.
The optimistic spinning code is also modified to not stop spinning
when the handoff bit is set. This will prevent an occasional setting of
handoff bit from causing a bunch of optimistic spinners from entering
into the wait queue causing significant reduction in throughput.
On a 1-socket 22-core 44-thread Skylake system, the AIM7 shared_memory
workload was run with 7000 users. The throughput (jobs/min) of the
following kernels were as follows:
1) 5.2-rc6
- 8,092,486
2) 5.2-rc6 + tip's rwsem patches
- 7,567,568
3) 5.2-rc6 + tip's rwsem patches + this patch
- 7,954,545
Using perf-record(1), the %cpu time used by rwsem_down_write_slowpath(),
rwsem_down_write_failed() and their callees for the 3 kernels were 1.70%,
5.46% and 2.08% respectively.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: x86@kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20190625143913.24154-1-longman@redhat.com
IMA will use the module_signature format for append signatures, so export
the relevant definitions and factor out the code which verifies that the
appended signature trailer is valid.
Also, create a CONFIG_MODULE_SIG_FORMAT option so that IMA can select it
and be able to use mod_check_sig() without having to depend on either
CONFIG_MODULE_SIG or CONFIG_MODULES.
s390 duplicated the definition of struct module_signature so now they can
use the new <linux/module_signature.h> header instead.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Acked-by: Jessica Yu <jeyu@kernel.org>
Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Userspace can get suspend stats from the suspend stats debugfs node.
Since debugfs doesn't have stable ABI, expose suspend stats in
sysfs under /sys/power/suspend_stats.
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
memremap.c implements MM functionality for ZONE_DEVICE, so it really
should be in the mm/ directory, not the kernel/ one.
Link: http://lkml.kernel.org/r/20190722094143.18387-1-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel-doc parser doesn't handle expressions with %foo*. Instead,
when an asterisk should be part of a constant, it uses an alternative
notation: `foo*`.
Link: http://lkml.kernel.org/r/7f18c2e0b5e39e6b7eb55ddeb043b8b260b49f2d.1563361575.git.mchehab+samsung@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes a cascade of regressions that originally started with
the addition of the ia64 port, but only got fatal once we removed
most uses of block layer bounce buffering in Linux 4.18.
The reason is that while the original i386/PAE code that was the first
architecture that supported > 4GB of memory without an iommu decided to
leave bounce buffering to the subsystems, which in those days just mean
block and networking as no one else consumer arbitrary userspace memory.
Later with ia64, x86_64 and other ports we assumed that either an iommu
or something that fakes it up ("software IOTLB" in beautiful Intel
speak) is present and that subsystems can rely on that for dealing with
addressing limitations in devices. Except that the ARM LPAE scheme
that added larger physical address to 32-bit ARM did not follow that
scheme and thus only worked by chance and only for block and networking
I/O directly to highmem.
Long story, short fix - add swiotlb support to arm when build for LPAE
platforms, which actuallys turns out to be pretty trivial with the
modern dma-direct / swiotlb code to fix the Linux 4.18-ish regression.
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Merge tag 'arm-swiotlb-5.3' of git://git.infradead.org/users/hch/dma-mapping
Pull arm swiotlb support from Christoph Hellwig:
"This fixes a cascade of regressions that originally started with the
addition of the ia64 port, but only got fatal once we removed most
uses of block layer bounce buffering in Linux 4.18.
The reason is that while the original i386/PAE code that was the first
architecture that supported > 4GB of memory without an iommu decided
to leave bounce buffering to the subsystems, which in those days just
mean block and networking as no one else consumed arbitrary userspace
memory.
Later with ia64, x86_64 and other ports we assumed that either an
iommu or something that fakes it up ("software IOTLB" in beautiful
Intel speak) is present and that subsystems can rely on that for
dealing with addressing limitations in devices. Except that the ARM
LPAE scheme that added larger physical address to 32-bit ARM did not
follow that scheme and thus only worked by chance and only for block
and networking I/O directly to highmem.
Long story, short fix - add swiotlb support to arm when build for LPAE
platforms, which actuallys turns out to be pretty trivial with the
modern dma-direct / swiotlb code to fix the Linux 4.18-ish regression"
* tag 'arm-swiotlb-5.3' of git://git.infradead.org/users/hch/dma-mapping:
arm: use swiotlb for bounce buffering on LPAE configs
dma-mapping: check pfn validity in dma_common_{mmap,get_sgtable}
- fix alignment issues introduced in the CMA allocation rework
(Nicolin Chen)
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Merge tag 'dma-mapping-5.3-3' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping regression fixes from Christoph Hellwig:
"Two related regression fixes for changes from this merge window to fix
alignment issues introduced in the CMA allocation rework (Nicolin
Chen)"
* tag 'dma-mapping-5.3-3' of git://git.infradead.org/users/hch/dma-mapping:
dma-contiguous: page-align the size in dma_free_contiguous()
dma-contiguous: do not overwrite align in dma_alloc_contiguous()
The more aggressive forward-progress tests can interfere with rcutorture
shutdown, resulting in false-positive diagnostics. This commit therefore
ends any such tests 30 seconds prior to shutdown.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
It is possible that the rcuperf kernel test runs concurrently with init
starting up. During this time, the system is running all grace periods
as expedited. However, rcuperf can also be run for normal GP tests.
Right now, it depends on a holdoff time before starting the test to
ensure grace periods start later. This works fine with the default
holdoff time however it is not robust in situations where init takes
greater than the holdoff time to finish running. Or, as in my case:
I modified the rcuperf test locally to also run a thread that did
preempt disable/enable in a loop. This had the effect of slowing down
init. The end result was that the "batches:" counter in rcuperf was 0
causing a division by 0 error in the results. This counter was 0 because
only expedited GPs seem to happen, not normal ones which led to the
rcu_state.gp_seq counter remaining constant across grace periods which
unexpectedly happen to be expedited. The system was running expedited
RCU all the time because rcu_unexpedited_gp() would not have run yet
from init. In other words, the test would concurrently with init
booting in expedited GP mode.
To fix this properly, this commit waits until system_state is set to
SYSTEM_RUNNING before starting the test. This change is made just
before kernel_init() invokes rcu_end_inkernel_boot(), and this latter
is what turns off boot-time expediting of RCU grace periods.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
The functions torture_onoff_cleanup() and torture_shuffle_cleanup()
are declared static and marked EXPORT_SYMBOL_GPL(), which is at best an
odd combination. Because these functions are not used outside of the
kernel/torture.c file they are defined in, this commit removes their
EXPORT_SYMBOL_GPL() marking.
Fixes: cc47ae0830 ("rcutorture: Abstract torture-test cleanup")
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
During an actual call_rcu() flood, there would be frequent trips to
userspace (in-kernel call_rcu() floods must be otherwise housebroken).
Userspace execution allows a great many things to interrupt execution,
and rcutorture needs to also allow such interruptions. This commit
therefore causes call_rcu() floods to occasionally invoke schedule(),
thus preventing spurious rcutorture failures due to other parts of the
kernel becoming irate at the call_rcu() flood events.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
The rcu_bh rcuperf type was removed by commit 620d246065cd("rcuperf:
Remove the "rcu_bh" and "sched" torture types"), but it lives on in the
MODULE_PARM_DESC() of perf_type. This commit therefore changes that
module-parameter description to substitute srcu for rcu_bh.
Signed-off-by: Xiao Yang <ice_yangxiao@163.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
The debug_locks flag can never be true at the end of
rcu_read_lock_sched_held() because it is already checked by the earlier
call todebug_lockdep_rcu_enabled(). This commit therefore removes this
redundant check.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
The rcu_dereference_raw_notrace() API name is confusing. It is equivalent
to rcu_dereference_raw() except that it also does sparse pointer checking.
There are only a few users of rcu_dereference_raw_notrace(). This patches
renames all of them to be rcu_dereference_raw_check() with the "_check()"
indicating sparse checking.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Fix checkpatch warnings about parentheses. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
The return value of rcu_spawn_one_boost_kthread() is not used any longer.
This commit therefore changes its return type from int to void, and
removes the cast to void from its callers.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Because pointer output is now obfuscated, and because what you really
want to know is whether or not the callback lists are empty, this commit
replaces the srcu_data structure's head callback pointer printout with
a single character that is "." is the callback list is empty or "C"
otherwise.
This is the only remaining user of rcu_segcblist_head(), so this
commit also removes this function's definition. It also turns out that
rcu_segcblist_tail() no longer has any callers, so this commit removes
that function's definition while in the area. They were both marked
"Interim", and their end has come.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
The synchronize_rcu_expedited() function has an INIT_WORK_ONSTACK(),
but lacks the corresponding destroy_work_on_stack(). This commit
therefore adds destroy_work_on_stack().
Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
This commit adds a rcu_cpu_stall_ftrace_dump kernel boot parameter, that,
when set, causes the trace buffer to be dumped after an RCU CPU stall
warning is printed. This kernel boot parameter is disabled by default,
maintaining compatibility with previous behavior.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Commit bb73c52bad ("rcu: Don't disable preemption for Tiny and Tree
RCU readers") removed the barrier() calls from rcu_read_lock() and
rcu_write_lock() in CONFIG_PREEMPT=n&&CONFIG_PREEMPT_COUNT=n kernels.
Within RCU, this commit was OK, but it failed to account for things like
get_user() that can pagefault and that can be reordered by the compiler.
Lack of the barrier() calls in rcu_read_lock() and rcu_read_unlock()
can cause these page faults to migrate into RCU read-side critical
sections, which in CONFIG_PREEMPT=n kernels could result in too-short
grace periods and arbitrary misbehavior. Please see commit 386afc9114
("spinlocks and preemption points need to be at least compiler barriers")
and Linus's commit 66be4e66a7 ("rcu: locking and unlocking need to
always be at least barriers"), this last of which restores the barrier()
call to both rcu_read_lock() and rcu_read_unlock().
This commit removes barrier() calls that are no longer needed given that
the addition of them in Linus's commit noted above. The combination of
this commit and Linus's commit effectively reverts commit bb73c52bad
("rcu: Don't disable preemption for Tiny and Tree RCU readers").
Reported-by: Herbert Xu <herbert@gondor.apana.org.au>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
[ paulmck: Fix embarrassing typo located by Alan Stern. ]
The TASKS03 and TREE04 rcutorture scenarios produce the following
lockdep complaint:
------------------------------------------------------------------------
================================
WARNING: inconsistent lock state
5.2.0-rc1+ #513 Not tainted
--------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
migration/1/14 [HC0[0]:SC0[0]:HE1:SE1] takes:
(____ptrval____) (tick_broadcast_lock){?...}, at: tick_broadcast_offline+0xf/0x70
{IN-HARDIRQ-W} state was registered at:
lock_acquire+0xb0/0x1c0
_raw_spin_lock_irqsave+0x3c/0x50
tick_broadcast_switch_to_oneshot+0xd/0x40
tick_switch_to_oneshot+0x4f/0xd0
hrtimer_run_queues+0xf3/0x130
run_local_timers+0x1c/0x50
update_process_times+0x1c/0x50
tick_periodic+0x26/0xc0
tick_handle_periodic+0x1a/0x60
smp_apic_timer_interrupt+0x80/0x2a0
apic_timer_interrupt+0xf/0x20
_raw_spin_unlock_irqrestore+0x4e/0x60
rcu_nocb_gp_kthread+0x15d/0x590
kthread+0xf3/0x130
ret_from_fork+0x3a/0x50
irq event stamp: 171
hardirqs last enabled at (171): [<ffffffff8a201a37>] trace_hardirqs_on_thunk+0x1a/0x1c
hardirqs last disabled at (170): [<ffffffff8a201a53>] trace_hardirqs_off_thunk+0x1a/0x1c
softirqs last enabled at (0): [<ffffffff8a264ee0>] copy_process.part.56+0x650/0x1cb0
softirqs last disabled at (0): [<0000000000000000>] 0x0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(tick_broadcast_lock);
<Interrupt>
lock(tick_broadcast_lock);
*** DEADLOCK ***
1 lock held by migration/1/14:
#0: (____ptrval____) (clockevents_lock){+.+.}, at: tick_offline_cpu+0xf/0x30
stack backtrace:
CPU: 1 PID: 14 Comm: migration/1 Not tainted 5.2.0-rc1+ #513
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Bochs 01/01/2011
Call Trace:
dump_stack+0x5e/0x8b
print_usage_bug+0x1fc/0x216
? print_shortest_lock_dependencies+0x1b0/0x1b0
mark_lock+0x1f2/0x280
__lock_acquire+0x1e0/0x18f0
? __lock_acquire+0x21b/0x18f0
? _raw_spin_unlock_irqrestore+0x4e/0x60
lock_acquire+0xb0/0x1c0
? tick_broadcast_offline+0xf/0x70
_raw_spin_lock+0x33/0x40
? tick_broadcast_offline+0xf/0x70
tick_broadcast_offline+0xf/0x70
tick_offline_cpu+0x16/0x30
take_cpu_down+0x7d/0xa0
multi_cpu_stop+0xa2/0xe0
? cpu_stop_queue_work+0xc0/0xc0
cpu_stopper_thread+0x6d/0x100
smpboot_thread_fn+0x169/0x240
kthread+0xf3/0x130
? sort_range+0x20/0x20
? kthread_cancel_delayed_work_sync+0x10/0x10
ret_from_fork+0x3a/0x50
------------------------------------------------------------------------
To reproduce, run the following rcutorture test:
tools/testing/selftests/rcutorture/bin/kvm.sh --duration 5 --kconfig "CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y" --configs "TASKS03 TREE04"
It turns out that tick_broadcast_offline() was an innocent bystander.
After all, interrupts are supposed to be disabled throughout
take_cpu_down(), and therefore should have been disabled upon entry to
tick_offline_cpu() and thus to tick_broadcast_offline(). This suggests
that one of the CPU-hotplug notifiers was incorrectly enabling interrupts,
and leaving them enabled on return.
Some debugging code showed that the culprit was sched_cpu_dying().
It had irqs enabled after return from sched_tick_stop(). Which in turn
had irqs enabled after return from cancel_delayed_work_sync(). Which is a
wrapper around __cancel_work_timer(). Which can sleep in the case where
something else is concurrently trying to cancel the same delayed work,
and as Thomas Gleixner pointed out on IRC, sleeping is a decidedly bad
idea when you are invoked from take_cpu_down(), regardless of the state
you leave interrupts in upon return.
Code inspection located no reason why the delayed work absolutely
needed to be canceled from sched_tick_stop(): The work is not
bound to the outgoing CPU by design, given that the whole point is
to collect statistics without disturbing the outgoing CPU.
This commit therefore simply drops the cancel_delayed_work_sync() from
sched_tick_stop(). Instead, a new ->state field is added to the tick_work
structure so that the delayed-work handler function sched_tick_remote()
can avoid reposting itself. A cpu_is_offline() check is also added to
sched_tick_remote() to avoid mucking with the state of an offlined CPU
(though it does appear safe to do so). The sched_tick_start() and
sched_tick_stop() functions also update ->state, and sched_tick_start()
also schedules the delayed work if ->state indicates that it is not
already in flight.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
[ paulmck: Apply Peter Zijlstra and Frederic Weisbecker atomics feedback. ]
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Security is a wonderful thing, but so is the ability to debug based on
lockdep warnings. This commit therefore makes lockdep lock addresses
visible in the clear.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Because __rcu_read_unlock() can be preempted just before the call to
rcu_read_unlock_special(), it is possible for a task to be preempted just
before it would have fully exited its RCU read-side critical section.
This would result in a needless extension of that critical section until
that task was resumed, which might in turn result in a needlessly
long grace period, needless RCU priority boosting, and needless
force-quiescent-state actions. Therefore, rcu_note_context_switch()
invokes __rcu_read_unlock() followed by rcu_preempt_deferred_qs() when
it detects this situation. This action by rcu_note_context_switch()
ends the RCU read-side critical section immediately.
Of course, once the task resumes, it will invoke rcu_read_unlock_special()
redundantly. This is harmless because the fact that a preemption
happened means that interrupts, preemption, and softirqs cannot
have been disabled, so there would be no deferred quiescent state.
While ->rcu_read_lock_nesting remains less than zero, none of the
->rcu_read_unlock_special.b bits can be set, and they were all zeroed by
the call to rcu_note_context_switch() at task-preemption time. Therefore,
setting ->rcu_read_unlock_special.b.exp_hint to false has no effect.
Therefore, the extra call to rcu_preempt_deferred_qs_irqrestore()
would return immediately. With one possible exception, which is
if an expedited grace period started just as the task was being
resumed, which could leave ->exp_deferred_qs set. This will cause
rcu_preempt_deferred_qs_irqrestore() to invoke rcu_report_exp_rdp(),
reporting the quiescent state, just as it should. (Such an expedited
grace period won't affect the preemption code path due to interrupts
having already been disabled.)
But when rcu_note_context_switch() invokes __rcu_read_unlock(), it
is doing so with preemption disabled, hence __rcu_read_unlock() will
unconditionally defer the quiescent state, only to immediately invoke
rcu_preempt_deferred_qs(), thus immediately reporting the deferred
quiescent state. It turns out to be safe (and faster) to instead
just invoke rcu_preempt_deferred_qs() without the __rcu_read_unlock()
middleman.
Because this is the invocation during the preemption (as opposed to
the invocation just after the resume), at least one of the bits in
->rcu_read_unlock_special.b must be set and ->rcu_read_lock_nesting
must be negative. This means that rcu_preempt_need_deferred_qs() must
return true, avoiding the early exit from rcu_preempt_deferred_qs().
Thus, rcu_preempt_deferred_qs_irqrestore() will be invoked immediately,
as required.
This commit therefore simplifies the CONFIG_PREEMPT=y version of
rcu_note_context_switch() by removing the "else if" branch of its
"if" statement. This change means that all callers that would have
invoked rcu_read_unlock_special() followed by rcu_preempt_deferred_qs()
will now simply invoke rcu_preempt_deferred_qs(), thus avoiding the
rcu_read_unlock_special() middleman when __rcu_read_unlock() is preempted.
Cc: rcu@vger.kernel.org
Cc: kernel-team@android.com
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Threaded interrupts provide additional interesting interactions between
RCU and raise_softirq() that can result in self-deadlocks in v5.0-2 of
the Linux kernel. These self-deadlocks can be provoked in susceptible
kernels within a few minutes using the following rcutorture command on
an 8-CPU system:
tools/testing/selftests/rcutorture/bin/kvm.sh --duration 5 --configs "TREE03" --bootargs "threadirqs"
Although post-v5.2 RCU commits have at least greatly reduced the
probability of these self-deadlocks, this was entirely by accident.
Although this sort of accident should be rowdily celebrated on those
rare occasions when it does occur, such celebrations should be quickly
followed by a principled patch, which is what this patch purports to be.
The key point behind this patch is that when in_interrupt() returns
true, __raise_softirq_irqoff() will never attempt a wakeup. Therefore,
if in_interrupt(), calls to raise_softirq*() are both safe and
extremely cheap.
This commit therefore replaces the in_irq() calls in the "if" statement
in rcu_read_unlock_special() with in_interrupt() and simplifies the
"if" condition to the following:
if (irqs_were_disabled && use_softirq &&
(in_interrupt() ||
(exp && !t->rcu_read_unlock_special.b.deferred_qs))) {
raise_softirq_irqoff(RCU_SOFTIRQ);
} else {
/* Appeal to the scheduler. */
}
The rationale behind the "if" condition is as follows:
1. irqs_were_disabled: If interrupts are enabled, we should
instead appeal to the scheduler so as to let the upcoming
irq_enable()/local_bh_enable() do the rescheduling for us.
2. use_softirq: If this kernel isn't using softirq, then
raise_softirq_irqoff() will be unhelpful.
3. a. in_interrupt(): If this returns true, the subsequent
call to raise_softirq_irqoff() is guaranteed not to
do a wakeup, so that call will be both very cheap and
quite safe.
b. Otherwise, if !in_interrupt() the raise_softirq_irqoff()
might do a wakeup, which is expensive and, in some
contexts, unsafe.
i. The "exp" (an expedited RCU grace period is being
blocked) says that the wakeup is worthwhile, and:
ii. The !.deferred_qs says that scheduler locks
cannot be held, so the wakeup will be safe.
Backporting this requires considerable care, so no auto-backport, please!
Fixes: 05f415715c ("rcu: Speed up expedited GPs when interrupting RCU reader")
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
In !use_softirq runs, we clearly cannot rely on raise_softirq() and
its lightweight bit setting, so we must instead do some form of wakeup.
In the absence of a self-IPI when interrupts are disabled, these wakeups
can be delayed until the next interrupt occurs. This means that calling
invoke_rcu_core() doesn't actually do any expediting.
In this case, it is better to take the "else" clause, which sets the
current CPU's resched bits and, if there is an expedited grace period
in flight, uses IRQ-work to force the needed self-IPI. This commit
therefore removes the "else if" clause that calls invoke_rcu_core().
Reported-by: Scott Wood <swood@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Since we always allocate memory, allocate just a little bit more
for the BPF program in case it need to override user input with
bigger value. The canonical example is TCP_CONGESTION where
input string might be too small to override (nv -> bbr or cubic).
16 bytes are chosen to match the size of TCP_CA_NAME_MAX and can
be extended in the future if needed.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This adds the P_PIDFD type to waitid().
One of the last remaining bits for the pidfd api is to make it possible
to wait on pidfds. With P_PIDFD added to waitid() the parts of userspace
that want to use the pidfd api to exclusively manage processes can do so
now.
One of the things this will unblock in the future is the ability to make
it possible to retrieve the exit status via waitid(P_PIDFD) for
non-parent processes if handed a _suitable_ pidfd that has this feature
set. This is similar to what you can do on FreeBSD with kqueue(). It
might even end up being possible to wait on a process as a non-parent if
an appropriate property is enabled on the pidfd.
With P_PIDFD no scoping of the process identified by the pidfd is
possible, i.e. it explicitly blocks things such as wait4(-1), wait4(0),
waitid(P_ALL), waitid(P_PGID) etc. It only allows for semantics
equivalent to wait4(pid), waitid(P_PID). Users that need scoping should
rely on pid-based wait*() syscalls for now.
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/20190727222229.6516-2-christian@brauner.io
Timer deletion on PREEMPT_RT is prone to priority inversion and live
locks. The hrtimer code has a synchronization mechanism for this. Posix CPU
timers will grow one.
But that mechanism cannot be invoked while holding the k_itimer lock
because that can deadlock against the running timer callback. So the lock
must be dropped which allows the timer to be freed.
The timer free can be prevented by taking RCU readlock before dropping the
lock, but because the rcu_head is part of the 'it' union a concurrent free
will overwrite the hrtimer on which the task is trying to synchronize.
Move the rcu_head out of the union to prevent this.
[ tglx: Fixed up kernel-doc. Rewrote changelog ]
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://lkml.kernel.org/r/20190730223828.965541887@linutronix.de
As a preparatory step for adding the PREEMPT RT specific synchronization
mechanism to wait for a running timer callback, rework the timer cancel
retry loops so they call a common function. This allows trivial
substitution in one place.
Originally-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190730223828.874901027@linutronix.de
do_timer_settime() has a 'flags' argument and uses 'flag' for the interrupt
flags, which is confusing at best.
Rename the argument so 'flags' can be used for interrupt flags as usual.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190730223828.782664411@linutronix.de
Use the hrtimer_cancel_wait_running() synchronization mechanism to prevent
priority inversion and live locks on PREEMPT_RT.
As a benefit the retry loop gains the missing cpu_relax() on !RT.
[ tglx: Split out of combo patch ]
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
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://lkml.kernel.org/r/20190730223828.690771827@linutronix.de
Use the hrtimer_cancel_wait_running() synchronization mechanism to prevent
priority inversion and live locks on PREEMPT_RT.
[ tglx: Split out of combo patch ]
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
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://lkml.kernel.org/r/20190730223828.508744705@linutronix.de
SCHED_DEADLINE inactive timer needs to run in hardirq context (as
dl_task_timer already does) on PREEMPT_RT
Change the mode to HRTIMER_MODE_REL_HARD.
[ tglx: Fixed up the start site, so mode debugging works ]
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190731103715.4047-1-juri.lelli@redhat.com
When PREEMPT_RT is enabled, the soft interrupt thread can be preempted. If
the soft interrupt thread is preempted in the middle of a timer callback,
then calling del_timer_sync() can lead to two issues:
- If the caller is on a remote CPU then it has to spin wait for the timer
handler to complete. This can result in unbound priority inversion.
- If the caller originates from the task which preempted the timer
handler on the same CPU, then spin waiting for the timer handler to
complete is never going to end.
To avoid these issues, add a new lock to the timer base which is held
around the execution of the timer callbacks. If del_timer_sync() detects
that the timer callback is currently running, it blocks on the expiry
lock. When the callback is finished, the expiry lock is dropped by the
softirq thread which wakes up the waiter and the system makes progress.
This addresses both the priority inversion and the life lock issues.
This mechanism is not used for timers which are marked IRQSAFE as for those
preemption is disabled accross the callback and therefore this situation
cannot happen. The callbacks for such timers need to be individually
audited for RT compliance.
The same issue can happen in virtual machines when the vCPU which runs a
timer callback is scheduled out. If a second vCPU of the same guest calls
del_timer_sync() it will spin wait for the other vCPU to be scheduled back
in. The expiry lock mechanism would avoid that. It'd be trivial to enable
this when paravirt spinlocks are enabled in a guest, but it's not clear
whether this is an actual problem in the wild, so for now it's an RT only
mechanism.
As the softirq thread can be preempted with PREEMPT_RT=y, the SMP variant
of del_timer_sync() needs to be used on UP as well.
[ tglx: Refactored it for mainline ]
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
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://lkml.kernel.org/r/20190726185753.832418500@linutronix.de
When PREEMPT_RT is enabled, the soft interrupt thread can be preempted. If
the soft interrupt thread is preempted in the middle of a timer callback,
then calling hrtimer_cancel() can lead to two issues:
- If the caller is on a remote CPU then it has to spin wait for the timer
handler to complete. This can result in unbound priority inversion.
- If the caller originates from the task which preempted the timer
handler on the same CPU, then spin waiting for the timer handler to
complete is never going to end.
To avoid these issues, add a new lock to the timer base which is held
around the execution of the timer callbacks. If hrtimer_cancel() detects
that the timer callback is currently running, it blocks on the expiry
lock. When the callback is finished, the expiry lock is dropped by the
softirq thread which wakes up the waiter and the system makes progress.
This addresses both the priority inversion and the life lock issues.
The same issue can happen in virtual machines when the vCPU which runs a
timer callback is scheduled out. If a second vCPU of the same guest calls
hrtimer_cancel() it will spin wait for the other vCPU to be scheduled back
in. The expiry lock mechanism would avoid that. It'd be trivial to enable
this when paravirt spinlocks are enabled in a guest, but it's not clear
whether this is an actual problem in the wild, so for now it's an RT only
mechanism.
[ tglx: Refactored it for mainline ]
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
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://lkml.kernel.org/r/20190726185753.737767218@linutronix.de
On PREEMPT_RT enabled kernels hrtimers which are not explicitely marked for
hard interrupt expiry mode are moved into soft interrupt context either for
latency reasons or because the hrtimer callback takes regular spinlocks or
invokes other functions which are not suitable for hard interrupt context
on PREEMPT_RT.
The hrtimer_sleeper callback is RT compatible in hard interrupt context,
but there is a latency concern: Untrusted userspace can spawn many threads
which arm timers for the same expiry time on the same CPU. On expiry that
causes a latency spike due to the wakeup of a gazillion threads.
OTOH, priviledged real-time user space applications rely on the low latency
of hard interrupt wakeups. These syscall related wakeups are all based on
hrtimer sleepers.
If the current task is in a real-time scheduling class, mark the mode for
hard interrupt expiry.
[ tglx: Split out of a larger combo patch. Added changelog ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190726185753.645792403@linutronix.de
On PREEMPT_RT not all hrtimers can be expired in hard interrupt context
even if that is perfectly fine on a PREEMPT_RT=n kernel, e.g. because they
take regular spinlocks. Also for latency reasons PREEMPT_RT tries to defer
most hrtimers' expiry into softirq context.
hrtimers marked with HRTIMER_MODE_HARD must be kept in hard interrupt
context expiry mode. Add the required logic.
No functional change for PREEMPT_RT=n kernels.
[ tglx: Split out of a larger combo patch. Added changelog ]
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://lkml.kernel.org/r/20190726185753.551967692@linutronix.de
The tick related hrtimers, which drive the scheduler tick and hrtimer based
broadcasting are required to expire in hard interrupt context for obvious
reasons.
Mark them so PREEMPT_RT kernels wont move them to soft interrupt expiry.
Make the horribly formatted RCU_NONIDLE bracket maze readable while at it.
No functional change,
[ tglx: Split out from larger combo patch. Add changelog ]
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://lkml.kernel.org/r/20190726185753.459144407@linutronix.de
The watchdog hrtimer must expire in hard interrupt context even on
PREEMPT_RT=y kernels as otherwise the hard/softlockup detection logic would
not work.
No functional change.
[ tglx: Split out from larger combo patch. Added changelog ]
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://lkml.kernel.org/r/20190726185753.262895510@linutronix.de
To guarantee that the multiplexing mechanism and the hrtimer driven events
work on PREEMPT_RT enabled kernels it's required that the related hrtimers
expire in hard interrupt context. Mark them so PREEMPT_RT kernels wont
defer them to soft interrupt context.
No functional change.
[ tglx: Split out of larger combo patch. Added changelog ]
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://lkml.kernel.org/r/20190726185753.169509224@linutronix.de
The scheduler related hrtimers need to expire in hard interrupt context
even on PREEMPT_RT enabled kernels. Mark then as such.
No functional change.
[ tglx: Split out from larger combo patch. Add changelog. ]
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://lkml.kernel.org/r/20190726185753.077004842@linutronix.de
hrtimer_start_range_ns() has a WARN_ONCE() which verifies that a timer
which is marker for softirq expiry is not queued in the hard interrupt base
and vice versa.
When PREEMPT_RT is enabled, timers which are not explicitely marked to
expire in hard interrupt context are deferrred to the soft interrupt. So
the regular check would trigger.
Change the check, so when PREEMPT_RT is enabled, it is verified that the
timers marked for hard interrupt expiry are not tried to be queued for soft
interrupt expiry or any of the unmarked and softirq marked is tried to be
expired in hard interrupt context.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
hrtimer_sleepers will gain a scheduling class dependent treatment on
PREEMPT_RT. Use the new hrtimer_sleeper_start_expires() function to make
that possible.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
hrtimer_sleepers will gain a scheduling class dependent treatment on
PREEMPT_RT. Create a wrapper around hrtimer_start_expires() to make that
possible.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
hrtimer_init_sleeper() calls require prior initialisation of the hrtimer
object which is embedded into the hrtimer_sleeper.
Combine the initialization and spare a function call. Fixup all call sites.
This is also a preparatory change for PREEMPT_RT to do hrtimer sleeper
specific initializations of the embedded hrtimer without modifying any of
the call sites.
No functional change.
[ anna-maria: Minor cleanups ]
[ tglx: Adopted to the removal of the task argument of
hrtimer_init_sleeper() and trivial polishing.
Folded a fix from Stephen Rothwell for the vsoc code ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190726185752.887468908@linutronix.de
- Fix trace event header include guards, as several did not match
the #define to the #ifdef
- Remove a redundant test to ftrace_graph_notrace_addr() that
was accidentally added.
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Merge tag 'trace-v5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Two minor fixes:
- Fix trace event header include guards, as several did not match the
#define to the #ifdef
- Remove a redundant test to ftrace_graph_notrace_addr() that was
accidentally added"
* tag 'trace-v5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
fgraph: Remove redundant ftrace_graph_notrace_addr() test
tracing: Fix header include guards in trace event headers
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by
CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same
functionality which today depends on CONFIG_PREEMPT.
Switch kprobes conditional over to CONFIG_PREEMPTION.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20190726212124.516286187@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by
CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same
functionality which today depends on CONFIG_PREEMPT.
Switch the conditionals in the tracer over to CONFIG_PREEMPTION.
This is the first step to make the tracer work on RT. The other small
tweaks are submitted separately.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20190726212124.409766323@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by
CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same
functionality which today depends on CONFIG_PREEMPT.
Switch the conditionals in RCU to use CONFIG_PREEMPTION.
That's the first step towards RCU on RT. The further tweaks are work in
progress. This neither touches the selftest bits which need a closer look
by Paul.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20190726212124.210156346@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by
CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same
functionality which today depends on CONFIG_PREEMPT.
Switch the preemption code, scheduler and init task over to use
CONFIG_PREEMPTION.
That's the first step towards RT in that area. The more complex changes are
coming separately.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20190726212124.117528401@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We already have tested it before. The second one should be removed.
With this change, the performance should have little improvement.
Link: http://lkml.kernel.org/r/20190730140850.7927-1-changbin.du@gmail.com
Cc: stable@vger.kernel.org
Fixes: 9cd2992f2d ("fgraph: Have set_graph_notrace only affect function_graph tracer")
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
All callers hand in 'current' and that's the only task pointer which
actually makes sense. Remove the task argument and set current in the
function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190726185752.791885290@linutronix.de
Since commit b191d6491b ("pidfd: fix a poll race when setting exit_state")
we unconditionally set exit_state to EXIT_ZOMBIE before calling into
do_notify_parent(). This was done to eliminate a race when querying
exit_state in do_notify_pidfd().
Back then we decided to do the absolute minimal thing to fix this and
not touch the rest of the exit_notify() function where exit_state is
set.
Since this fix has not caused any issues change the setting of
exit_state to EXIT_DEAD in the autoreap case to account for the fact hat
exit_state is set to EXIT_ZOMBIE unconditionally. This fix was planned
but also explicitly requested in [1] and makes the whole code more
consistent.
/* References */
[1]: https://lore.kernel.org/lkml/CAHk-=wigcxGFR2szue4wavJtH5cYTTeNES=toUBVGsmX0rzX+g@mail.gmail.com
Signed-off-by: Christian Brauner <christian@brauner.io>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
The FSF does not reside in "675 Mass Ave, Cambridge" anymore...
let's replace the old GPL boilerplate code with a proper SPDX
identifier instead.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some arches (e.g., arm64, x86) have moved towards non-executable
module_alloc() allocations for security hardening reasons. That means
that the module loader will need to set the text section of a module to
executable, regardless of whether or not CONFIG_STRICT_MODULE_RWX is set.
When CONFIG_STRICT_MODULE_RWX=y, module section allocations are always
page-aligned to handle memory rwx permissions. On some arches with
CONFIG_STRICT_MODULE_RWX=n however, when setting the module text to
executable, the BUG_ON() in frob_text() gets triggered since module
section allocations are not page-aligned when CONFIG_STRICT_MODULE_RWX=n.
Since the set_memory_* API works with pages, and since we need to call
set_memory_x() regardless of whether CONFIG_STRICT_MODULE_RWX is set, we
might as well page-align all module section allocations for ease of
managing rwx permissions of module sections (text, rodata, etc).
Fixes: 2eef1399a8 ("modules: fix BUG when load module with rodata=n")
Reported-by: Martin Kaiser <lists@kaiser.cx>
Reported-by: Bartosz Golaszewski <brgl@bgdev.pl>
Tested-by: David Lechner <david@lechnology.com>
Tested-by: Martin Kaiser <martin@kaiser.cx>
Tested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
A common pattern when using xdp_redirect_map() is to create a device map
where the lookup key is simply ifindex. Because device maps are arrays,
this leaves holes in the map, and the map has to be sized to fit the
largest ifindex, regardless of how many devices actually are actually
needed in the map.
This patch adds a second type of device map where the key is looked up
using a hashmap, instead of being used as an array index. This allows maps
to be densely packed, so they can be smaller.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The subsequent patch to add a new devmap sub-type can re-use much of the
initialisation and allocation code, so refactor it into separate functions.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Previously a condition got missed where the pidfd waiters are awakened
before the exit_state gets set. This can result in a missed notification
[1] and the polling thread waiting forever.
It is fixed now, however it would be nice to avoid this kind of issue
going unnoticed in the future. So just add a warning to catch it in the
future.
/* References */
[1]: https://lore.kernel.org/lkml/20190717172100.261204-1-joel@joelfernandes.org/
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20190724164816.201099-1-joel@joelfernandes.org
Signed-off-by: Christian Brauner <christian@brauner.io>
According to the original dma_direct_alloc_pages() code:
{
unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
if (!dma_release_from_contiguous(dev, page, count))
__free_pages(page, get_order(size));
}
The count parameter for dma_release_from_contiguous() was page
aligned before the right-shifting operation, while the new API
dma_free_contiguous() forgets to have PAGE_ALIGN() at the size.
So this patch simply adds it to prevent any corner case.
Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The dma_alloc_contiguous() limits align at CONFIG_CMA_ALIGNMENT for
cma_alloc() however it does not restore it for the fallback routine.
This will result in a size mismatch between the allocation and free
when running into the fallback routines after cma_alloc() fails, if
the align is larger than CONFIG_CMA_ALIGNMENT.
This patch adds a cma_align to take care of cma_alloc() and prevent
the align from being overwritten.
Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Reported-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Pull scheduler fixes from Thomas Gleixner:
"Two fixes for the fair scheduling class:
- Prevent freeing memory which is accessible by concurrent readers
- Make the RCU annotations for numa groups consistent"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/fair: Use RCU accessors consistently for ->numa_group
sched/fair: Don't free p->numa_faults with concurrent readers
Pull perf fixes from Thomas Gleixner:
"A pile of perf related fixes:
Kernel:
- Fix SLOTS PEBS event constraints for Icelake CPUs
- Add the missing mask bit to allow counting hardware generated
prefetches on L3 for Icelake CPUs
- Make the test for hypervisor platforms more accurate (as far as
possible)
- Handle PMUs correctly which override event->cpu
- Yet another missing fallthrough annotation
Tools:
perf.data:
- Fix loading of compressed data split across adjacent records
- Fix buffer size setting for processing CPU topology perf.data
header.
perf stat:
- Fix segfault for event group in repeat mode
- Always separate "stalled cycles per insn" line, it was being
appended to the "instructions" line.
perf script:
- Fix --max-blocks man page description.
- Improve man page description of metrics.
- Fix off by one in brstackinsn IPC computation.
perf probe:
- Avoid calling freeing routine multiple times for same pointer.
perf build:
- Do not use -Wshadow on gcc < 4.8, avoiding too strict warnings
treated as errors, breaking the build"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel: Mark expected switch fall-throughs
perf/core: Fix creating kernel counters for PMUs that override event->cpu
perf/x86: Apply more accurate check on hypervisor platform
perf/x86/intel: Fix invalid Bit 13 for Icelake MSR_OFFCORE_RSP_x register
perf/x86/intel: Fix SLOTS PEBS event constraint
perf build: Do not use -Wshadow on gcc < 4.8
perf probe: Avoid calling freeing routine multiple times for same pointer
perf probe: Set pev->nargs to zero after freeing pev->args entries
perf session: Fix loading of compressed data split across adjacent records
perf stat: Always separate stalled cycles per insn
perf stat: Fix segfault for event group in repeat mode
perf tools: Fix proper buffer size for feature processing
perf script: Fix off by one in brstackinsn IPC computation
perf script: Improve man page description of metrics
perf script: Fix --max-blocks man page description
Pull locking fixes from Thomas Gleixner:
"A set of locking fixes:
- Address the fallout of the rwsem rework. Missing ACQUIREs and a
sanity check to prevent a use-after-free
- Add missing checks for unitialized mutexes when mutex debugging is
enabled.
- Remove the bogus code in the generic SMP variant of
arch_futex_atomic_op_inuser()
- Fixup the #ifdeffery in lockdep to prevent compile warnings"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/mutex: Test for initialized mutex
locking/lockdep: Clean up #ifdef checks
locking/lockdep: Hide unused 'class' variable
locking/rwsem: Add ACQUIRE comments
tty/ldsem, locking/rwsem: Add missing ACQUIRE to read_failed sleep loop
lcoking/rwsem: Add missing ACQUIRE to read_slowpath sleep loop
locking/rwsem: Add missing ACQUIRE to read_slowpath exit when queue is empty
locking/rwsem: Don't call owner_on_cpu() on read-owner
futex: Cleanup generic SMP variant of arch_futex_atomic_op_inuser()
With the removal of the padata timer, padata_do_serial no longer
needs special CPU handling, so remove it.
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The function padata_reorder will use a timer when it cannot progress
while completed jobs are outstanding (pd->reorder_objects > 0). This
is suboptimal as if we do end up using the timer then it would have
introduced a gratuitous delay of one second.
In fact we can easily distinguish between whether completed jobs
are outstanding and whether we can make progress. All we have to
do is look at the next pqueue list.
This patch does that by replacing pd->processed with pd->cpu so
that the next pqueue is more accessible.
A work queue is used instead of the original try_again to avoid
hogging the CPU.
Note that we don't bother removing the work queue in
padata_flush_queues because the whole premise is broken. You
cannot flush async crypto requests so it makes no sense to even
try. A subsequent patch will fix it by replacing it with a ref
counting scheme.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Alexei Starovoitov says:
====================
pull-request: bpf 2019-07-25
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) fix segfault in libbpf, from Andrii.
2) fix gso_segs access, from Eric.
3) tls/sockmap fixes, from Jakub and John.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The access() (and faccessat()) credentials change can cause an
unnecessary load on the RCU machinery because every access() call ends
up freeing the temporary access credential using RCU.
This isn't really noticeable on small machines, but if you have hundreds
of cores you can cause huge slowdowns due to RCU storms.
It's easy to avoid: the temporary access crededntials aren't actually
normally accessed using RCU at all, so we can avoid the whole issue by
just marking them as such.
* access-creds:
access: avoid the RCU grace period for the temporary subjective credentials
Compiling a kernel with both FAIR_GROUP_SCHED=n and RT_GROUP_SCHED=n
will generate a compiler warning:
kernel/sched/core.c: In function 'sched_init':
kernel/sched/core.c:5906:32: warning: variable 'ptr' set but not used
It is unnecessary to have both "alloc_size" and "ptr", so just combine
them.
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: valentin.schneider@arm.com
Link: https://lkml.kernel.org/r/20190720012319.884-1-cai@lca.pw
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On !CONFIG_RT_GROUP_SCHED configurations it is currently not possible to
move RT tasks between cgroups to which CPU controller has been attached;
but it is oddly possible to first move tasks around and then make them
RT (setschedule to FIFO/RR).
E.g.:
# mkdir /sys/fs/cgroup/cpu,cpuacct/group1
# chrt -fp 10 $$
# echo $$ > /sys/fs/cgroup/cpu,cpuacct/group1/tasks
bash: echo: write error: Invalid argument
# chrt -op 0 $$
# echo $$ > /sys/fs/cgroup/cpu,cpuacct/group1/tasks
# chrt -fp 10 $$
# cat /sys/fs/cgroup/cpu,cpuacct/group1/tasks
2345
2598
# chrt -p 2345
pid 2345's current scheduling policy: SCHED_FIFO
pid 2345's current scheduling priority: 10
Also, as Michal noted, it is currently not possible to enable CPU
controller on unified hierarchy with !CONFIG_RT_GROUP_SCHED (if there
are any kernel RT threads in root cgroup, they can't be migrated to the
newly created CPU controller's root in cgroup_update_dfl_csses()).
Existing code comes with a comment saying the "we don't support RT-tasks
being in separate groups". Such comment is however stale and belongs to
pre-RT_GROUP_SCHED times. Also, it doesn't make much sense for
!RT_GROUP_ SCHED configurations, since checks related to RT bandwidth
are not performed at all in these cases.
Make moving RT tasks between CPU controller groups viable by removing
special case check for RT (and DEADLINE) tasks.
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: lizefan@huawei.com
Cc: longman@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: rostedt@goodmis.org
Link: https://lkml.kernel.org/r/20190719063455.27328-1-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
No synchronisation mechanism exists between the cpuset subsystem and
calls to function __sched_setscheduler(). As such, it is possible that
new root domains are created on the cpuset side while a deadline
acceptance test is carried out in __sched_setscheduler(), leading to a
potential oversell of CPU bandwidth.
Grab cpuset_rwsem read lock from core scheduler, so to prevent
situations such as the one described above from happening.
The only exception is normalize_rt_tasks() which needs to work under
tasklist_lock and can't therefore grab cpuset_rwsem. We are fine with
this, as this function is only called by sysrq and, if that gets
triggered, DEADLINE guarantees are already gone out of the window
anyway.
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bristot@redhat.com
Cc: claudio@evidence.eu.com
Cc: lizefan@huawei.com
Cc: longman@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: mathieu.poirier@linaro.org
Cc: rostedt@goodmis.org
Cc: tj@kernel.org
Cc: tommaso.cucinotta@santannapisa.it
Link: https://lkml.kernel.org/r/20190719140000.31694-9-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
cpuset_rwsem is going to be acquired from sched_setscheduler() with a
following patch. There are however paths (e.g., spawn_ksoftirqd) in
which sched_scheduler() is eventually called while holding hotplug lock;
this creates a dependecy between hotplug lock (to be always acquired
first) and cpuset_rwsem (to be always acquired after hotplug lock).
Fix paths which currently take the two locks in the wrong order (after
a following patch is applied).
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bristot@redhat.com
Cc: claudio@evidence.eu.com
Cc: lizefan@huawei.com
Cc: longman@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: mathieu.poirier@linaro.org
Cc: rostedt@goodmis.org
Cc: tj@kernel.org
Cc: tommaso.cucinotta@santannapisa.it
Link: https://lkml.kernel.org/r/20190719140000.31694-7-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Holding cpuset_mutex means that cpusets are stable (only the holder can
make changes) and this is required for fixing a synchronization issue
between cpusets and scheduler core. However, grabbing cpuset_mutex from
setscheduler() hotpath (as implemented in a later patch) is a no-go, as
it would create a bottleneck for tasks concurrently calling
setscheduler().
Convert cpuset_mutex to be a percpu_rwsem (cpuset_rwsem), so that
setscheduler() will then be able to read lock it and avoid concurrency
issues.
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bristot@redhat.com
Cc: claudio@evidence.eu.com
Cc: lizefan@huawei.com
Cc: longman@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: mathieu.poirier@linaro.org
Cc: rostedt@goodmis.org
Cc: tj@kernel.org
Cc: tommaso.cucinotta@santannapisa.it
Link: https://lkml.kernel.org/r/20190719140000.31694-6-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When the topology of root domains is modified by CPUset or CPUhotplug
operations information about the current deadline bandwidth held in the
root domain is lost.
This patch addresses the issue by recalculating the lost deadline
bandwidth information by circling through the deadline tasks held in
CPUsets and adding their current load to the root domain they are
associated with.
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
[ Various additional modifications. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bristot@redhat.com
Cc: claudio@evidence.eu.com
Cc: lizefan@huawei.com
Cc: longman@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: rostedt@goodmis.org
Cc: tj@kernel.org
Cc: tommaso.cucinotta@santannapisa.it
Link: https://lkml.kernel.org/r/20190719140000.31694-4-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Calls to task_rq_unlock() are done several times in the
__sched_setscheduler() function. This is fine when only the rq lock needs to be
handled but not so much when other locks come into play.
This patch streamlines the release of the rq lock so that only one
location need to be modified when dealing with more than one lock.
No change of functionality is introduced by this patch.
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bristot@redhat.com
Cc: claudio@evidence.eu.com
Cc: lizefan@huawei.com
Cc: longman@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: tommaso.cucinotta@santannapisa.it
Link: https://lkml.kernel.org/r/20190719140000.31694-3-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Introduce the partition_sched_domains_locked() function by taking
the mutex locking code out of the original function. That way
the work done by partition_sched_domains_locked() can be reused
without dropping the mutex lock.
No change of functionality is introduced by this patch.
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bristot@redhat.com
Cc: claudio@evidence.eu.com
Cc: lizefan@huawei.com
Cc: longman@redhat.com
Cc: luca.abeni@santannapisa.it
Cc: rostedt@goodmis.org
Cc: tommaso.cucinotta@santannapisa.it
Link: https://lkml.kernel.org/r/20190719140000.31694-2-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The same formula to check utilization against capacity (after
considering capacity_margin) is already used at 5 different locations.
This patch creates a new macro, fits_capacity(), which can be used from
all these locations without exposing the details of it and hence
simplify code.
All the 5 code locations are updated as well to use it..
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/b477ac75a2b163048bdaeb37f57b4c3f04f75a31.1559631700.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In real product setup, there will be houseeking CPUs in each nodes, it
is prefer to do housekeeping from local node, fallback to global online
cpumask if failed to find houseeking CPU from local node.
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1561711901-4755-2-git-send-email-wanpengli@tencent.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched_info_on() is called with unlikely hint, however, the test
is to be a constant(1) on which compiler will do nothing when
make defconfig, so remove the hint.
Also, fix a lack of {}.
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: up2wing@gmail.com
Cc: wang.liang82@zte.com.cn
Cc: xue.zhihong@zte.com.cn
Link: https://lkml.kernel.org/r/1562301307-43002-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Returning the pointer that was passed in allows us to write
slightly more idiomatic code. Convert a few users.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190704221323.24290-1-willy@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We try to find an idle CPU to run the next task, but in case we don't
find an idle CPU it is better to pick a CPU which will run the task the
soonest, for performance reason.
A CPU which isn't idle but has only SCHED_IDLE activity queued on it
should be a good target based on this criteria as any normal fair task
will most likely preempt the currently running SCHED_IDLE task
immediately. In fact, choosing a SCHED_IDLE CPU over a fully idle one
shall give better results as it should be able to run the task sooner
than an idle CPU (which requires to be woken up from an idle state).
This patch updates both fast and slow paths with this optimization.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: chris.redpath@arm.com
Cc: quentin.perret@linaro.org
Cc: songliubraving@fb.com
Cc: steven.sistare@oracle.com
Cc: subhra.mazumdar@oracle.com
Cc: tkjos@google.com
Link: https://lkml.kernel.org/r/eeafa25fdeb6f6edd5b2da716bc8f0ba7708cbcf.1561523542.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
time/tick-broadcast: Fix tick_broadcast_offline() lockdep complaint
The TASKS03 and TREE04 rcutorture scenarios produce the following
lockdep complaint:
WARNING: inconsistent lock state
5.2.0-rc1+ #513 Not tainted
--------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
migration/1/14 [HC0[0]:SC0[0]:HE1:SE1] takes:
(____ptrval____) (tick_broadcast_lock){?...}, at: tick_broadcast_offline+0xf/0x70
{IN-HARDIRQ-W} state was registered at:
lock_acquire+0xb0/0x1c0
_raw_spin_lock_irqsave+0x3c/0x50
tick_broadcast_switch_to_oneshot+0xd/0x40
tick_switch_to_oneshot+0x4f/0xd0
hrtimer_run_queues+0xf3/0x130
run_local_timers+0x1c/0x50
update_process_times+0x1c/0x50
tick_periodic+0x26/0xc0
tick_handle_periodic+0x1a/0x60
smp_apic_timer_interrupt+0x80/0x2a0
apic_timer_interrupt+0xf/0x20
_raw_spin_unlock_irqrestore+0x4e/0x60
rcu_nocb_gp_kthread+0x15d/0x590
kthread+0xf3/0x130
ret_from_fork+0x3a/0x50
irq event stamp: 171
hardirqs last enabled at (171): [<ffffffff8a201a37>] trace_hardirqs_on_thunk+0x1a/0x1c
hardirqs last disabled at (170): [<ffffffff8a201a53>] trace_hardirqs_off_thunk+0x1a/0x1c
softirqs last enabled at (0): [<ffffffff8a264ee0>] copy_process.part.56+0x650/0x1cb0
softirqs last disabled at (0): [<0000000000000000>] 0x0
[...]
To reproduce, run the following rcutorture test:
$ tools/testing/selftests/rcutorture/bin/kvm.sh --duration 5 --kconfig "CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y" --configs "TASKS03 TREE04"
It turns out that tick_broadcast_offline() was an innocent bystander.
After all, interrupts are supposed to be disabled throughout
take_cpu_down(), and therefore should have been disabled upon entry to
tick_offline_cpu() and thus to tick_broadcast_offline(). This suggests
that one of the CPU-hotplug notifiers was incorrectly enabling interrupts,
and leaving them enabled on return.
Some debugging code showed that the culprit was sched_cpu_dying().
It had irqs enabled after return from sched_tick_stop(). Which in turn
had irqs enabled after return from cancel_delayed_work_sync(). Which is a
wrapper around __cancel_work_timer(). Which can sleep in the case where
something else is concurrently trying to cancel the same delayed work,
and as Thomas Gleixner pointed out on IRC, sleeping is a decidedly bad
idea when you are invoked from take_cpu_down(), regardless of the state
you leave interrupts in upon return.
Code inspection located no reason why the delayed work absolutely
needed to be canceled from sched_tick_stop(): The work is not
bound to the outgoing CPU by design, given that the whole point is
to collect statistics without disturbing the outgoing CPU.
This commit therefore simply drops the cancel_delayed_work_sync() from
sched_tick_stop(). Instead, a new ->state field is added to the tick_work
structure so that the delayed-work handler function sched_tick_remote()
can avoid reposting itself. A cpu_is_offline() check is also added to
sched_tick_remote() to avoid mucking with the state of an offlined CPU
(though it does appear safe to do so). The sched_tick_start() and
sched_tick_stop() functions also update ->state, and sched_tick_start()
also schedules the delayed work if ->state indicates that it is not
already in flight.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
[ paulmck: Apply Peter Zijlstra and Frederic Weisbecker atomics feedback. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190625165238.GJ26519@linux.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The load_balance() has a dedicated mecanism to detect when an imbalance
is due to CPU affinity and must be handled at parent level. In this case,
the imbalance field of the parent's sched_group is set.
The description of sg_imbalanced() gives a typical example of two groups
of 4 CPUs each and 4 tasks each with a cpumask covering 1 CPU of the first
group and 3 CPUs of the second group. Something like:
{ 0 1 2 3 } { 4 5 6 7 }
* * * *
But the load_balance fails to fix this UC on my octo cores system
made of 2 clusters of quad cores.
Whereas the load_balance is able to detect that the imbalanced is due to
CPU affinity, it fails to fix it because the imbalance field is cleared
before letting parent level a chance to run. In fact, when the imbalance is
detected, the load_balance reruns without the CPU with pinned tasks. But
there is no other running tasks in the situation described above and
everything looks balanced this time so the imbalance field is immediately
cleared.
The imbalance field should not be cleared if there is no other task to move
when the imbalance is detected.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1561996022-28829-1-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We only need to set the callback_head worker function once, do it
during sched_fork().
While at it, move the comment regarding double task_work addition to
init_numa_balancing(), since the double add sentinel is first set there.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: mgorman@suse.de
Cc: riel@surriel.com
Link: https://lkml.kernel.org/r/20190715102508.32434-3-valentin.schneider@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
To reference task_numa_work() from within init_numa_balancing(), we
need the former to be declared before the latter. Do just that.
This is a pure code movement.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: mgorman@suse.de
Cc: riel@surriel.com
Link: https://lkml.kernel.org/r/20190715102508.32434-2-valentin.schneider@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Re-evaluating the bitmap wheight of the online cpus bitmap in every
invocation of num_online_cpus() over and over is a pretty useless
exercise. Especially when num_online_cpus() is used in code paths
like the IPI delivery of x86 or the membarrier code.
Cache the number of online CPUs in the core and just return the cached
variable. The accessor function provides only a snapshot when used without
protection against concurrent CPU hotplug.
The storage needs to use an atomic_t because the kexec and reboot code
(ab)use set_cpu_online() in their 'shutdown' handlers without any form of
serialization as pointed out by Mathieu. Regular CPU hotplug usage is
properly serialized.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1907091622590.1634@nanos.tec.linutronix.de
The booted once information which is required to deal with the MCE
broadcast issue on X86 correctly is stored in the per cpu hotplug state,
which is perfectly fine for the intended purpose.
X86 needs that information for supporting NMI broadcasting via shortcuts,
but retrieving it from per cpu data is cumbersome.
Move it to a cpumask so the information can be checked against the
cpu_present_mask quickly.
No functional change intended.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190722105219.818822855@linutronix.de
Report the number of stack traces and the number of stack trace hash
chains. These two numbers are useful because these allow to estimate
the number of stack trace hash collisions.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/r/20190722182443.216015-5-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Although commit 669de8bda8 ("kernel/workqueue: Use dynamic lockdep keys
for workqueues") unregisters dynamic lockdep keys when a workqueue is
destroyed, a side effect of that commit is that all stack traces
associated with the lockdep key are leaked when a workqueue is destroyed.
Fix this by storing each unique stack trace once. Other changes in this
patch are:
- Use NULL instead of { .nr_entries = 0 } to represent 'no trace'.
- Store a pointer to a stack trace in struct lock_class and struct
lock_list instead of storing 'nr_entries' and 'offset'.
This patch avoids that the following program triggers the "BUG:
MAX_STACK_TRACE_ENTRIES too low!" complaint:
#include <fcntl.h>
#include <unistd.h>
int main()
{
for (;;) {
int fd = open("/dev/infiniband/rdma_cm", O_RDWR);
close(fd);
}
}
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Reported-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yuyang Du <duyuyang@gmail.com>
Link: https://lkml.kernel.org/r/20190722182443.216015-4-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Make it clear to humans and to the compiler that the stack trace
('entries') arguments are not modified.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/r/20190722182443.216015-3-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch does not change the behavior of the lockdep code.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/r/20190722182443.216015-2-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some hardware PMU drivers will override perf_event.cpu inside their
event_init callback. This causes a lockdep splat when initialized through
the kernel API:
WARNING: CPU: 0 PID: 250 at kernel/events/core.c:2917 ctx_sched_out+0x78/0x208
pc : ctx_sched_out+0x78/0x208
Call trace:
ctx_sched_out+0x78/0x208
__perf_install_in_context+0x160/0x248
remote_function+0x58/0x68
generic_exec_single+0x100/0x180
smp_call_function_single+0x174/0x1b8
perf_install_in_context+0x178/0x188
perf_event_create_kernel_counter+0x118/0x160
Fix this by calling perf_install_in_context with event->cpu, just like
perf_event_open
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Frank Li <Frank.li@nxp.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/c4ebe0503623066896d7046def4d6b1e06e0eb2e.1563972056.git.leonard.crestez@nxp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
An uninitialized/ zeroed mutex will go unnoticed because there is no
check for it. There is a magic check in the unlock's slowpath path which
might go unnoticed if the unlock happens in the fastpath.
Add a ->magic check early in the mutex_lock() and mutex_trylock() path.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190703092125.lsdf4gpsh2plhavb@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As Will Deacon points out, CONFIG_PROVE_LOCKING implies TRACE_IRQFLAGS,
so the conditions I added in the previous patch, and some others in the
same file can be simplified by only checking for the former.
No functional change.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Yuyang Du <duyuyang@gmail.com>
Fixes: 886532aee3 ("locking/lockdep: Move mark_lock() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING")
Link: https://lkml.kernel.org/r/20190628102919.2345242-1-arnd@arndb.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The usage is now hidden in an #ifdef, so we need to move
the variable itself in there as well to avoid this warning:
kernel/locking/lockdep_proc.c:203:21: error: unused variable 'class' [-Werror,-Wunused-variable]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yuyang Du <duyuyang@gmail.com>
Cc: frederic@kernel.org
Fixes: 68d41d8c94 ("locking/lockdep: Fix lock used or unused stats error")
Link: https://lkml.kernel.org/r/20190715092809.736834-1-arnd@arndb.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since we just reviewed read_slowpath for ACQUIRE correctness, add a
few coments to retain our findings.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While reviewing another read_slowpath patch, both Will and I noticed
another missing ACQUIRE, namely:
X = 0;
CPU0 CPU1
rwsem_down_read()
for (;;) {
set_current_state(TASK_UNINTERRUPTIBLE);
X = 1;
rwsem_up_write();
rwsem_mark_wake()
atomic_long_add(adjustment, &sem->count);
smp_store_release(&waiter->task, NULL);
if (!waiter.task)
break;
...
}
r = X;
Allows 'r == 0'.
Reported-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
LTP mtest06 has been observed to occasionally hit "still mapped when
deleted" and following BUG_ON on arm64.
The extra mapcount originated from pagefault handler, which handled
pagefault for vma that has already been detached. vma is detached
under mmap_sem write lock by detach_vmas_to_be_unmapped(), which
also invalidates vmacache.
When the pagefault handler (under mmap_sem read lock) calls
find_vma(), vmacache_valid() wrongly reports vmacache as valid.
After rwsem down_read() returns via 'queue empty' path (as of v5.2),
it does so without an ACQUIRE on sem->count:
down_read()
__down_read()
rwsem_down_read_failed()
__rwsem_down_read_failed_common()
raw_spin_lock_irq(&sem->wait_lock);
if (list_empty(&sem->wait_list)) {
if (atomic_long_read(&sem->count) >= 0) {
raw_spin_unlock_irq(&sem->wait_lock);
return sem;
The problem can be reproduced by running LTP mtest06 in a loop and
building the kernel (-j $NCPUS) in parallel. It does reproduces since
v4.20 on arm64 HPE Apollo 70 (224 CPUs, 256GB RAM, 2 nodes). It
triggers reliably in about an hour.
The patched kernel ran fine for 10+ hours.
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dbueso@suse.de
Fixes: 4b486b535c ("locking/rwsem: Exit read lock slowpath if queue empty & no writer")
Link: https://lkml.kernel.org/r/50b8914e20d1d62bb2dee42d342836c2c16ebee7.1563438048.git.jstancek@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
For writer, the owner value is cleared on unlock. For reader, it is
left intact on unlock for providing better debugging aid on crash dump
and the unlock of one reader may not mean the lock is free.
As a result, the owner_on_cpu() shouldn't be used on read-owner
as the task pointer value may not be valid and it might have
been freed. That is the case in rwsem_spin_on_owner(), but not in
rwsem_can_spin_on_owner(). This can lead to use-after-free error from
KASAN. For example,
BUG: KASAN: use-after-free in rwsem_down_write_slowpath
(/home/miguel/kernel/linux/kernel/locking/rwsem.c:669
/home/miguel/kernel/linux/kernel/locking/rwsem.c:1125)
Fix this by checking for RWSEM_READER_OWNED flag before calling
owner_on_cpu().
Reported-by: Luis Henriques <lhenriques@suse.com>
Tested-by: Luis Henriques <lhenriques@suse.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: huang ying <huang.ying.caritas@gmail.com>
Fixes: 94a9717b3c ("locking/rwsem: Make rwsem->owner an atomic_long_t")
Link: https://lkml.kernel.org/r/81e82d5b-5074-77e8-7204-28479bbe0df0@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The old code used RCU annotations and accessors inconsistently for
->numa_group, which can lead to use-after-frees and NULL dereferences.
Let all accesses to ->numa_group use proper RCU helpers to prevent such
issues.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Fixes: 8c8a743c50 ("sched/numa: Use {cpu, pid} to create task groups for shared faults")
Link: https://lkml.kernel.org/r/20190716152047.14424-3-jannh@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When going through execve(), zero out the NUMA fault statistics instead of
freeing them.
During execve, the task is reachable through procfs and the scheduler. A
concurrent /proc/*/sched reader can read data from a freed ->numa_faults
allocation (confirmed by KASAN) and write it back to userspace.
I believe that it would also be possible for a use-after-free read to occur
through a race between a NUMA fault and execve(): task_numa_fault() can
lead to task_numa_compare(), which invokes task_weight() on the currently
running task of a different CPU.
Another way to fix this would be to make ->numa_faults RCU-managed or add
extra locking, but it seems easier to wipe the NUMA fault statistics on
execve.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Fixes: 82727018b0 ("sched/numa: Call task_numa_free() from do_execve()")
Link: https://lkml.kernel.org/r/20190716152047.14424-1-jannh@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
It turns out that 'access()' (and 'faccessat()') can cause a lot of RCU
work because it installs a temporary credential that gets allocated and
freed for each system call.
The allocation and freeing overhead is mostly benign, but because
credentials can be accessed under the RCU read lock, the freeing
involves a RCU grace period.
Which is not a huge deal normally, but if you have a lot of access()
calls, this causes a fair amount of seconday damage: instead of having a
nice alloc/free patterns that hits in hot per-CPU slab caches, you have
all those delayed free's, and on big machines with hundreds of cores,
the RCU overhead can end up being enormous.
But it turns out that all of this is entirely unnecessary. Exactly
because access() only installs the credential as the thread-local
subjective credential, the temporary cred pointer doesn't actually need
to be RCU free'd at all. Once we're done using it, we can just free it
synchronously and avoid all the RCU overhead.
So add a 'non_rcu' flag to 'struct cred', which can be set by users that
know they only use it in non-RCU context (there are other potential
users for this). We can make it a union with the rcu freeing list head
that we need for the RCU case, so this doesn't need any extra storage.
Note that this also makes 'get_current_cred()' clear the new non_rcu
flag, in case we have filesystems that take a long-term reference to the
cred and then expect the RCU delayed freeing afterwards. It's not
entirely clear that this is required, but it makes for clear semantics:
the subjective cred remains non-RCU as long as you only access it
synchronously using the thread-local accessors, but you _can_ use it as
a generic cred if you want to.
It is possible that we should just remove the whole RCU markings for
->cred entirely. Only ->real_cred is really supposed to be accessed
through RCU, and the long-term cred copies that nfs uses might want to
explicitly re-enable RCU freeing if required, rather than have
get_current_cred() do it implicitly.
But this is a "minimal semantic changes" change for the immediate
problem.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jan Glauber <jglauber@marvell.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Jayachandran Chandrasekharan Nair <jnair@marvell.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Check that the pfn returned from arch_dma_coherent_to_pfn refers to
a valid page and reject the mmap / get_sgtable requests otherwise.
Based on the arm implementation of the mmap and get_sgtable methods.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Vignesh Raghavendra <vigneshr@ti.com>
We could only handle the case that css exists
and css_try_get_online() fails.
Signed-off-by: Peng Wang <rocking@whu.edu.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
A string which did not contain a data format specification should be put
into a sequence. Thus use the corresponding function “seq_puts”.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Tejun Heo <tj@kernel.org>
The very first check in test_pkt_md_access is failing on s390, which
happens because loading a part of a struct __sk_buff field produces
an incorrect result.
The preprocessed code of the check is:
{
__u8 tmp = *((volatile __u8 *)&skb->len +
((sizeof(skb->len) - sizeof(__u8)) / sizeof(__u8)));
if (tmp != ((*(volatile __u32 *)&skb->len) & 0xFF)) return 2;
};
clang generates the following code for it:
0: 71 21 00 03 00 00 00 00 r2 = *(u8 *)(r1 + 3)
1: 61 31 00 00 00 00 00 00 r3 = *(u32 *)(r1 + 0)
2: 57 30 00 00 00 00 00 ff r3 &= 255
3: 5d 23 00 1d 00 00 00 00 if r2 != r3 goto +29 <LBB0_10>
Finally, verifier transforms it to:
0: (61) r2 = *(u32 *)(r1 +104)
1: (bc) w2 = w2
2: (74) w2 >>= 24
3: (bc) w2 = w2
4: (54) w2 &= 255
5: (bc) w2 = w2
The problem is that when verifier emits the code to replace a partial
load of a struct __sk_buff field (*(u8 *)(r1 + 3)) with a full load of
struct sk_buff field (*(u32 *)(r1 + 104)), an optional shift and a
bitwise AND, it assumes that the machine is little endian and
incorrectly decides to use a shift.
Adjust shift count calculation to account for endianness.
Fixes: 31fd85816d ("bpf: permits narrower load from bpf program context fields")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
After previous changes the suspend-to-idle code flow can be
integrated more tightly with the generic system suspend code flow
by making suspend_enter() call s2idle_loop() later and removing
the direct invocations of dpm_noirq_begin(),
dpm_noirq_suspend_devices(), dpm_noirq_end(), and
dpm_noirq_resume_devices() from the latter, so do that.
This change is not expected to alter functionality.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
After commit 33e4f80ee6 ("ACPI / PM: Ignore spurious SCI wakeups
from suspend-to-idle") the "noirq" phases of device suspend and
resume may run for multiple times during suspend-to-idle, if there
are spurious system wakeup events while suspended. However, this
is complicated and fragile and actually unnecessary.
The main reason for doing this is that on some systems the EC may
signal system wakeup events (power button events, for example) as
well as events that should not cause the system to resume (spurious
system wakeup events). Thus, in order to determine whether or not
a given event signaled by the EC while suspended is a proper system
wakeup one, the EC GPE needs to be dispatched and to start with that
was achieved by allowing the ACPI SCI action handler to run, which
was only possible after calling resume_device_irqs().
However, dispatching the EC GPE this way turned out to take too much
time in some cases and some EC events might be missed due to that, so
commit 68e2201185 ("ACPI: EC: Dispatch the EC GPE directly on
s2idle wake") started to dispatch the EC GPE right after a wakeup
event has been detected, so in fact the full ACPI SCI action handler
doesn't need to run any more to deal with the wakeups coming from the
EC.
Use this observation to simplify the suspend-to-idle control flow
so that the "noirq" phases of device suspend and resume are each
run only once in every suspend-to-idle cycle, which is reported to
significantly reduce power drawn by some systems when suspended to
idle (by allowing them to reach a deep platform-wide low-power state
through the suspend-to-idle flow). [What appears to happen is that
the "noirq" resume of devices after a spurious EC wakeup brings some
devices into a state in which they prevent the platform from reaching
the deep low-power state going forward, even after a subsequent
"noirq" suspend phase, and on some systems the EC triggers such
wakeups already when the "noirq" suspend of devices is running for
the first time in the given suspend/resume cycle, so the platform
cannot reach the deep low-power state at all.]
First, make acpi_s2idle_wake() use the acpi_ec_dispatch_gpe() return
value to determine whether or not the wakeup may have been triggered
by the EC (in which case the system wakeup is canceled and ACPI
events are processed in order to determine whether or not the event
is a proper system wakeup one) and use rearm_wake_irq() (introduced
by a previous change) in it to rearm the ACPI SCI for system wakeup
detection in case the system will remain suspended.
Second, drop acpi_s2idle_sync(), which is not needed any more, and
the corresponding global platform suspend-to-idle callback.
Next, drop the pm_wakeup_pending() check (which is an optimization
only) from __device_suspend_noirq() to prevent it from returning
errors on system wakeups occurring before the "noirq" phase of
device suspend is complete (as in the case of suspend-to-idle it is
not known whether or not these wakeups are suprious at that point),
in order to avoid having to carry out a "noirq" resume of devices
on a spurious system wakeup.
Finally, change the code flow in s2idle_loop() to (1) run the
"noirq" suspend of devices once before starting the loop, (2) check
for spurious EC wakeups (via the platform ->wake callback) for the
first time before calling s2idle_enter(), and (3) run the "noirq"
resume of devices once after leaving the loop.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Introduce a new function, rearm_wake_irq(), allowing a wakeup IRQ
to be armed for systen wakeup detection again without running any
action handlers associated with it after it has been armed for
wakeup detection and triggered.
That is useful for IRQs, like ACPI SCI, that may deliver wakeup
as well as non-wakeup interrupts when armed for systen wakeup
detection. In those cases, it may be possible to determine whether
or not the delivered interrupt is a systen wakeup one without
running the entire action handler (or handlers, if the IRQ is
shared) for the IRQ, and if the interrupt turns out to be a
non-wakeup one, the IRQ can be rearmed with the help of the
new function.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Pull preemption Kconfig fix from Thomas Gleixner:
"The PREEMPT_RT stub config renamed PREEMPT to PREEMPT_LL and defined
PREEMPT outside of the menu and made it selectable by both PREEMPT_LL
and PREEMPT_RT.
Stupid me missed that 114 defconfigs select CONFIG_PREEMPT which
obviously can't work anymore. oldconfig builds are affected as well,
but it's more obvious as the user gets asked. [old]defconfig silently
fixes it up and selects PREEMPT_NONE.
Unbreak it by undoing the rename and adding a intermediate config
symbol which is selected by both PREEMPT and PREEMPT_RT. That requires
to chase down a few #ifdefs, but it's better than tweaking 114
defconfigs and annoying users"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/rt, Kconfig: Unbreak def/oldconfig with CONFIG_PREEMPT=y
The merge of the CONFIG_PREEMPT_RT stub renamed CONFIG_PREEMPT to
CONFIG_PREEMPT_LL which causes all defconfigs which have CONFIG_PREEMPT=y
set to fall back to CONFIG_PREEMPT_NONE because CONFIG_PREEMPT depends on
the preemption mode choice wich defaults to NONE. This also affects
oldconfig builds.
So rather than changing 114 defconfig files and being an annoyance to
users, revert the rename and select a new config symbol PREEMPTION. That
keeps everything working smoothly and the revelant ifdef's are going to be
fixed up step by step.
Reported-by: Mark Rutland <mark.rutland@arm.com>
Fixes: a50a3f4b6a ("sched/rt, Kconfig: Introduce CONFIG_PREEMPT_RT")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There is a race between reading task->exit_state in pidfd_poll and
writing it after do_notify_parent calls do_notify_pidfd. Expected
sequence of events is:
CPU 0 CPU 1
------------------------------------------------
exit_notify
do_notify_parent
do_notify_pidfd
tsk->exit_state = EXIT_DEAD
pidfd_poll
if (tsk->exit_state)
However nothing prevents the following sequence:
CPU 0 CPU 1
------------------------------------------------
exit_notify
do_notify_parent
do_notify_pidfd
pidfd_poll
if (tsk->exit_state)
tsk->exit_state = EXIT_DEAD
This causes a polling task to wait forever, since poll blocks because
exit_state is 0 and the waiting task is not notified again. A stress
test continuously doing pidfd poll and process exits uncovered this bug.
To fix it, we make sure that the task's exit_state is always set before
calling do_notify_pidfd.
Fixes: b53b0b9d9a ("pidfd: add polling support")
Cc: kernel-team@android.com
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20190717172100.261204-1-joel@joelfernandes.org
[christian@brauner.io: adapt commit message and drop unneeded changes from wait_task_zombie]
Signed-off-by: Christian Brauner <christian@brauner.io>
MPX is being removed from the kernel due to a lack of support in the
toolchain going forward (gcc).
The first step is to remove the userspace-visible ABIs so that applications
will stop using it. The most visible one are the enable/disable prctl()s.
Remove them first.
This is the most minimal and least invasive change needed to ensure that
apps stop using MPX with new kernels.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190705175321.DB42F0AD@viggo.jf.intel.com
Fix various regressions:
- force unencrypted dma-coherent buffers if encryption bit can't fit
into the dma coherent mask (Tom Lendacky)
- avoid limiting request size if swiotlb is not used (me)
- fix swiotlb handling in dma_direct_sync_sg_for_cpu/device
(Fugang Duan)
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Merge tag 'dma-mapping-5.3-1' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fixes from Christoph Hellwig:
"Fix various regressions:
- force unencrypted dma-coherent buffers if encryption bit can't fit
into the dma coherent mask (Tom Lendacky)
- avoid limiting request size if swiotlb is not used (me)
- fix swiotlb handling in dma_direct_sync_sg_for_cpu/device (Fugang
Duan)"
* tag 'dma-mapping-5.3-1' of git://git.infradead.org/users/hch/dma-mapping:
dma-direct: correct the physical addr in dma_direct_sync_sg_for_cpu/device
dma-direct: only limit the mapping size if swiotlb could be used
dma-mapping: add a dma_addressing_limited helper
dma-direct: Force unencrypted DMA under SME for certain DMA masks
Pull core fixes from Thomas Gleixner:
- A collection of objtool fixes which address recent fallout partially
exposed by newer toolchains, clang, BPF and general code changes.
- Force USER_DS for user stack traces
[ Note: the "objtool fixes" are not all to objtool itself, but for
kernel code that triggers objtool warnings.
Things like missing function size annotations, or code that confuses
the unwinder etc. - Linus]
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
objtool: Support conditional retpolines
objtool: Convert insn type to enum
objtool: Fix seg fault on bad switch table entry
objtool: Support repeated uses of the same C jump table
objtool: Refactor jump table code
objtool: Refactor sibling call detection logic
objtool: Do frame pointer check before dead end check
objtool: Change dead_end_function() to return boolean
objtool: Warn on zero-length functions
objtool: Refactor function alias logic
objtool: Track original function across branches
objtool: Add mcsafe_handle_tail() to the uaccess safe list
bpf: Disable GCC -fgcse optimization for ___bpf_prog_run()
x86/uaccess: Remove redundant CLACs in getuser/putuser error paths
x86/uaccess: Don't leak AC flag into fentry from mcsafe_handle_tail()
x86/uaccess: Remove ELF function annotation from copy_user_handle_tail()
x86/head/64: Annotate start_cpu0() as non-callable
x86/entry: Fix thunk function ELF sizes
x86/kvm: Don't call kvm_spurious_fault() from .fixup
x86/kvm: Replace vmx_vmenter()'s call to kvm_spurious_fault() with UD2
...
Pull smp fix from Thomas Gleixner:
"Add warnings to the smp function calls so callers from wrong contexts
get detected"
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
smp: Warn on function calls from softirq context
Pull CONFIG_PREEMPT_RT stub config from Thomas Gleixner:
"The real-time preemption patch set exists for almost 15 years now and
while the vast majority of infrastructure and enhancements have found
their way into the mainline kernel, the final integration of RT is
still missing.
Over the course of the last few years, we have worked on reducing the
intrusivenness of the RT patches by refactoring kernel infrastructure
to be more real-time friendly. Almost all of these changes were
benefitial to the mainline kernel on their own, so there was no
objection to integrate them.
Though except for the still ongoing printk refactoring, the remaining
changes which are required to make RT a first class mainline citizen
are not longer arguable as immediately beneficial for the mainline
kernel. Most of them are either reordering code flows or adding RT
specific functionality.
But this now has hit a wall and turned into a classic hen and egg
problem:
Maintainers are rightfully wary vs. these changes as they make only
sense if the final integration of RT into the mainline kernel takes
place.
Adding CONFIG_PREEMPT_RT aims to solve this as a clear sign that RT
will be fully integrated into the mainline kernel. The final
integration of the missing bits and pieces will be of course done with
the same careful approach as we have used in the past.
While I'm aware that you are not entirely enthusiastic about that, I
think that RT should receive the same treatment as any other widely
used out of tree functionality, which we have accepted into mainline
over the years.
RT has become the de-facto standard real-time enhancement and is
shipped by enterprise, embedded and community distros. It's in use
throughout a wide range of industries: telecommunications, industrial
automation, professional audio, medical devices, data acquisition,
automotive - just to name a few major use cases.
RT development is backed by a Linuxfoundation project which is
supported by major stakeholders of this technology. The funding will
continue over the actual inclusion into mainline to make sure that the
functionality is neither introducing regressions, regressing itself,
nor becomes subject to bitrot. There is also a lifely user community
around RT as well, so contrary to the grim situation 5 years ago, it's
a healthy project.
As RT is still a good vehicle to exercise rarely used code paths and
to detect hard to trigger issues, you could at least view it as a QA
tool if nothing else"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/rt, Kconfig: Introduce CONFIG_PREEMPT_RT
- s390 support for KVM selftests
- LAPIC timer offloading to housekeeping CPUs
- Extend an s390 optimization for overcommitted hosts to all architectures
- Debugging cleanups and improvements
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull more KVM updates from Paolo Bonzini:
"Mostly bugfixes, but also:
- s390 support for KVM selftests
- LAPIC timer offloading to housekeeping CPUs
- Extend an s390 optimization for overcommitted hosts to all
architectures
- Debugging cleanups and improvements"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (25 commits)
KVM: x86: Add fixed counters to PMU filter
KVM: nVMX: do not use dangling shadow VMCS after guest reset
KVM: VMX: dump VMCS on failed entry
KVM: x86/vPMU: refine kvm_pmu err msg when event creation failed
KVM: s390: Use kvm_vcpu_wake_up in kvm_s390_vcpu_wakeup
KVM: Boost vCPUs that are delivering interrupts
KVM: selftests: Remove superfluous define from vmx.c
KVM: SVM: Fix detection of AMD Errata 1096
KVM: LAPIC: Inject timer interrupt via posted interrupt
KVM: LAPIC: Make lapic timer unpinned
KVM: x86/vPMU: reset pmc->counter to 0 for pmu fixed_counters
KVM: nVMX: Ignore segment base for VMX memory operand when segment not FS or GS
kvm: x86: ioapic and apic debug macros cleanup
kvm: x86: some tsc debug cleanup
kvm: vmx: fix coccinelle warnings
x86: kvm: avoid constant-conversion warning
x86: kvm: avoid -Wsometimes-uninitized warning
KVM: x86: expose AVX512_BF16 feature to guest
KVM: selftests: enable pgste option for the linker on s390
KVM: selftests: Move kvm_create_max_vcpus test to generic code
...
It's clearly documented that smp function calls cannot be invoked from
softirq handling context. Unfortunately nothing enforces that or emits a
warning.
A single function call can be invoked from softirq context only via
smp_call_function_single_async().
The only legit context is task context, so add a warning to that effect.
Reported-by: luferry <luferry@163.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190718160601.GP3402@hirez.programming.kicks-ass.net
Dedicated instances are currently disturbed by unnecessary jitter due
to the emulated lapic timers firing on the same pCPUs where the
vCPUs reside. There is no hardware virtual timer on Intel for guest
like ARM, so both programming timer in guest and the emulated timer fires
incur vmexits. This patch tries to avoid vmexit when the emulated timer
fires, at least in dedicated instance scenario when nohz_full is enabled.
In that case, the emulated timers can be offload to the nearest busy
housekeeping cpus since APICv has been found for several years in server
processors. The guest timer interrupt can then be injected via posted interrupts,
which are delivered by the housekeeping cpu once the emulated timer fires.
The host should tuned so that vCPUs are placed on isolated physical
processors, and with several pCPUs surplus for busy housekeeping.
If disabled mwait/hlt/pause vmexits keep the vCPUs in non-root mode,
~3% redis performance benefit can be observed on Skylake server, and the
number of external interrupt vmexits drops substantially. Without patch
VM-EXIT Samples Samples% Time% Min Time Max Time Avg time
EXTERNAL_INTERRUPT 42916 49.43% 39.30% 0.47us 106.09us 0.71us ( +- 1.09% )
While with patch:
VM-EXIT Samples Samples% Time% Min Time Max Time Avg time
EXTERNAL_INTERRUPT 6871 9.29% 2.96% 0.44us 57.88us 0.72us ( +- 4.02% )
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull crypto fixes from Herbert Xu:
- Fix missed wake-up race in padata
- Use crypto_memneq in ccp
- Fix version check in ccp
- Fix fuzz test failure in ccp
- Fix potential double free in crypto4xx
- Fix compile warning in stm32
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
padata: use smp_mb in padata_reorder to avoid orphaned padata jobs
crypto: ccp - Fix SEV_VERSION_GREATER_OR_EQUAL
crypto: ccp/gcm - use const time tag comparison.
crypto: ccp - memset structure fields to zero before reuse
crypto: crypto4xx - fix a potential double free in ppc4xx_trng_probe
crypto: stm32/hash - Fix incorrect printk modifier for size_t
Removing ULONG_MAX as the marker for the user stack trace end,
made the tracing code not know where the end is. The end is now
marked with a zero (NULL) pointer. Eiichi fixed this in the tracing
code.
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Merge tag 'trace-v5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Eiichi Tsukata found a small bug from the fixup of the stack code
Removing ULONG_MAX as the marker for the user stack trace end, made
the tracing code not know where the end is. The end is now marked with
a zero (NULL) pointer. Eiichi fixed this in the tracing code"
* tag 'trace-v5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix user stack trace "??" output
Pull vfs mount updates from Al Viro:
"The first part of mount updates.
Convert filesystems to use the new mount API"
* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
mnt_init(): call shmem_init() unconditionally
constify ksys_mount() string arguments
don't bother with registering rootfs
init_rootfs(): don't bother with init_ramfs_fs()
vfs: Convert smackfs to use the new mount API
vfs: Convert selinuxfs to use the new mount API
vfs: Convert securityfs to use the new mount API
vfs: Convert apparmorfs to use the new mount API
vfs: Convert openpromfs to use the new mount API
vfs: Convert xenfs to use the new mount API
vfs: Convert gadgetfs to use the new mount API
vfs: Convert oprofilefs to use the new mount API
vfs: Convert ibmasmfs to use the new mount API
vfs: Convert qib_fs/ipathfs to use the new mount API
vfs: Convert efivarfs to use the new mount API
vfs: Convert configfs to use the new mount API
vfs: Convert binfmt_misc to use the new mount API
convenience helper: get_tree_single()
convenience helper get_tree_nodev()
vfs: Kill sget_userns()
...
Pull networking fixes from David Miller:
1) Fix AF_XDP cq entry leak, from Ilya Maximets.
2) Fix handling of PHY power-down on RTL8411B, from Heiner Kallweit.
3) Add some new PCI IDs to iwlwifi, from Ihab Zhaika.
4) Fix handling of neigh timers wrt. entries added by userspace, from
Lorenzo Bianconi.
5) Various cases of missing of_node_put(), from Nishka Dasgupta.
6) The new NET_ACT_CT needs to depend upon NF_NAT, from Yue Haibing.
7) Various RDS layer fixes, from Gerd Rausch.
8) Fix some more fallout from TCQ_F_CAN_BYPASS generalization, from
Cong Wang.
9) Fix FIB source validation checks over loopback, also from Cong Wang.
10) Use promisc for unsupported number of filters, from Justin Chen.
11) Missing sibling route unlink on failure in ipv6, from Ido Schimmel.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (90 commits)
tcp: fix tcp_set_congestion_control() use from bpf hook
ag71xx: fix return value check in ag71xx_probe()
ag71xx: fix error return code in ag71xx_probe()
usb: qmi_wwan: add D-Link DWM-222 A2 device ID
bnxt_en: Fix VNIC accounting when enabling aRFS on 57500 chips.
net: dsa: sja1105: Fix missing unlock on error in sk_buff()
gve: replace kfree with kvfree
selftests/bpf: fix test_xdp_noinline on s390
selftests/bpf: fix "valid read map access into a read-only array 1" on s390
net/mlx5: Replace kfree with kvfree
MAINTAINERS: update netsec driver
ipv6: Unlink sibling route in case of failure
liquidio: Replace vmalloc + memset with vzalloc
udp: Fix typo in net/ipv4/udp.c
net: bcmgenet: use promisc for unsupported filters
ipv6: rt6_check should return NULL if 'from' is NULL
tipc: initialize 'validated' field of received packets
selftests: add a test case for rp_filter
fib: relax source validation check for loopback packets
mlxsw: spectrum: Do not process learned records with a dummy FID
...
Merge yet more updates from Andrew Morton:
"The rest of MM and a kernel-wide procfs cleanup.
Summary of the more significant patches:
- Patch series "mm/memory_hotplug: Factor out memory block
devicehandling", v3. David Hildenbrand.
Some spring-cleaning of the memory hotplug code, notably in
drivers/base/memory.c
- "mm: thp: fix false negative of shmem vma's THP eligibility". Yang
Shi.
Fix /proc/pid/smaps output for THP pages used in shmem.
- "resource: fix locking in find_next_iomem_res()" + 1. Nadav Amit.
Bugfix and speedup for kernel/resource.c
- Patch series "mm: Further memory block device cleanups", David
Hildenbrand.
More spring-cleaning of the memory hotplug code.
- Patch series "mm: Sub-section memory hotplug support". Dan
Williams.
Generalise the memory hotplug code so that pmem can use it more
completely. Then remove the hacks from the libnvdimm code which
were there to work around the memory-hotplug code's constraints.
- "proc/sysctl: add shared variables for range check", Matteo Croce.
We have about 250 instances of
int zero;
...
.extra1 = &zero,
in the tree. This is a tree-wide sweep to make all those private
"zero"s and "one"s use global variables.
Alas, it isn't practical to make those two global integers const"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (38 commits)
proc/sysctl: add shared variables for range check
mm: migrate: remove unused mode argument
mm/sparsemem: cleanup 'section number' data types
libnvdimm/pfn: stop padding pmem namespaces to section alignment
libnvdimm/pfn: fix fsdax-mode namespace info-block zero-fields
mm/devm_memremap_pages: enable sub-section remap
mm: document ZONE_DEVICE memory-model implications
mm/sparsemem: support sub-section hotplug
mm/sparsemem: prepare for sub-section ranges
mm: kill is_dev_zone() helper
mm/hotplug: kill is_dev_zone() usage in __remove_pages()
mm/sparsemem: convert kmalloc_section_memmap() to populate_section_memmap()
mm/hotplug: prepare shrink_{zone, pgdat}_span for sub-section removal
mm/sparsemem: add helpers track active portions of a section at boot
mm/sparsemem: introduce a SECTION_IS_EARLY flag
mm/sparsemem: introduce struct mem_section_usage
drivers/base/memory.c: get rid of find_memory_block_hinted()
mm/memory_hotplug: move and simplify walk_memory_blocks()
mm/memory_hotplug: rename walk_memory_range() and pass start+size instead of pfns
mm: make register_mem_sect_under_node() static
...
Commit c5c27a0a58 ("x86/stacktrace: Remove the pointless ULONG_MAX
marker") removes ULONG_MAX marker from user stack trace entries but
trace_user_stack_print() still uses the marker and it outputs unnecessary
"??".
For example:
less-1911 [001] d..2 34.758944: <user stack trace>
=> <00007f16f2295910>
=> ??
=> ??
=> ??
=> ??
=> ??
=> ??
=> ??
The user stack trace code zeroes the storage before saving the stack, so if
the trace is shorter than the maximum number of entries it can terminate
the print loop if a zero entry is detected.
Link: http://lkml.kernel.org/r/20190630085438.25545-1-devel@etsukata.com
Cc: stable@vger.kernel.org
Fixes: 4285f2fcef ("tracing: Remove the ULONG_MAX stack trace hackery")
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
dma_map_sg() may use swiotlb buffer when the kernel command line includes
"swiotlb=force" or the dma_addr is out of dev->dma_mask range. After
DMA complete the memory moving from device to memory, then user call
dma_sync_sg_for_cpu() to sync with DMA buffer, and copy the original
virtual buffer to other space.
So dma_direct_sync_sg_for_cpu() should use swiotlb physical addr, not
the original physical addr from sg_phys(sg).
dma_direct_sync_sg_for_device() also has the same issue, correct it as
well.
Fixes: 55897af63091("dma-direct: merge swiotlb_dma_ops into the dma_direct code")
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
In the sysctl code the proc_dointvec_minmax() function is often used to
validate the user supplied value between an allowed range. This
function uses the extra1 and extra2 members from struct ctl_table as
minimum and maximum allowed value.
On sysctl handler declaration, in every source file there are some
readonly variables containing just an integer which address is assigned
to the extra1 and extra2 members, so the sysctl range is enforced.
The special values 0, 1 and INT_MAX are very often used as range
boundary, leading duplication of variables like zero=0, one=1,
int_max=INT_MAX in different source files:
$ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l
248
Add a const int array containing the most commonly used values, some
macros to refer more easily to the correct array member, and use them
instead of creating a local one for every object file.
This is the bloat-o-meter output comparing the old and new binary
compiled with the default Fedora config:
# scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o
add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164)
Data old new delta
sysctl_vals - 12 +12
__kstrtab_sysctl_vals - 12 +12
max 14 10 -4
int_max 16 - -16
one 68 - -68
zero 128 28 -100
Total: Before=20583249, After=20583085, chg -0.00%
[mcroce@redhat.com: tipc: remove two unused variables]
Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com
[akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c]
[arnd@arndb.de: proc/sysctl: make firmware loader table conditional]
Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de
[akpm@linux-foundation.org: fix fs/eventpoll.c]
Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Teach devm_memremap_pages() about the new sub-section capabilities of
arch_{add,remove}_memory(). Effectively, just replace all usage of
align_start, align_end, and align_size with res->start, res->end, and
resource_size(res). The existing sanity check will still make sure that
the two separate remap attempts do not collide within a sub-section (2MB
on x86).
Link: http://lkml.kernel.org/r/156092355542.979959.10060071713397030576.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Cc: Michal Hocko <mhocko@suse.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
find_next_iomem_res() shows up to be a source for overhead in dax
benchmarks.
Improve performance by not considering children of the tree if the top
level does not match. Since the range of the parents should include the
range of the children such check is redundant.
Running sysbench on dax (pmem emulation, with write_cache disabled):
sysbench fileio --file-total-size=3G --file-test-mode=rndwr \
--file-io-mode=mmap --threads=4 --file-fsync-mode=fdatasync run
Provides the following results:
events (avg/stddev)
-------------------
5.2-rc3: 1247669.0000/16075.39
w/patch: 1286320.5000/16402.72 (+3%)
Link: http://lkml.kernel.org/r/20190613045903.4922-3-namit@vmware.com
Signed-off-by: Nadav Amit <namit@vmware.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since resources can be removed, locking should ensure that the resource
is not removed while accessing it. However, find_next_iomem_res() does
not hold the lock while copying the data of the resource.
Keep holding the lock while the data is copied. While at it, change the
return value to a more informative value. It is disregarded by the
callers.
[akpm@linux-foundation.org: fix find_next_iomem_res() documentation]
Link: http://lkml.kernel.org/r/20190613045903.4922-2-namit@vmware.com
Fixes: ff3cc952d3 ("resource: Add remove_resource interface")
Signed-off-by: Nadav Amit <namit@vmware.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a new entry to the preemption menu which enables the real-time support
for the kernel. The choice is only enabled when an architecture supports
it.
It selects PREEMPT as the RT features depend on it. To achieve that the
existing PREEMPT choice is renamed to PREEMPT_LL which select PREEMPT as
well.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.ibm.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Clark Williams <williams@redhat.com>
Acked-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Daniel Wagner <wagi@monom.org>
Acked-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Acked-by: Julia Cartwright <julia@ni.com>
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Acked-by: Gratian Crisan <gratian.crisan@ni.com>
Acked-by: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Andrew Morton <akpm@linuxfoundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1907172200190.1778@nanos.tec.linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Alexei Starovoitov says:
====================
pull-request: bpf 2019-07-18
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) verifier precision propagation fix, from Andrii.
2) BTF size fix for typedefs, from Andrii.
3) a bunch of big endian fixes, from Ilya.
4) wide load from bpf_sock_addr fixes, from Stanislav.
5) a bunch of misc fixes from a number of developers.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Summary of modules changes for the 5.3 merge window:
- Code fixes and cleanups
- Fix bug where set_memory_x() wasn't being called when rodata=n
- Fix bug where -EEXIST was being returned for going modules
- Allow arches to override module_exit_section()
Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull module updates from Jessica Yu:
"Summary of modules changes for the 5.3 merge window:
- Code fixes and cleanups
- Fix bug where set_memory_x() wasn't being called when rodata=n
- Fix bug where -EEXIST was being returned for going modules
- Allow arches to override module_exit_section()"
* tag 'modules-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
modules: fix compile error if don't have strict module rwx
ARM: module: recognize unwind exit sections
module: allow arch overrides for .exit section names
modules: fix BUG when load module with rodata=n
kernel/module: Fix mem leak in module_add_modinfo_attrs
kernel: module: Use struct_size() helper
kernel/module.c: Only return -EEXIST for modules that have finished loading
On x86-64, with CONFIG_RETPOLINE=n, GCC's "global common subexpression
elimination" optimization results in ___bpf_prog_run()'s jumptable code
changing from this:
select_insn:
jmp *jumptable(, %rax, 8)
...
ALU64_ADD_X:
...
jmp *jumptable(, %rax, 8)
ALU_ADD_X:
...
jmp *jumptable(, %rax, 8)
to this:
select_insn:
mov jumptable, %r12
jmp *(%r12, %rax, 8)
...
ALU64_ADD_X:
...
jmp *(%r12, %rax, 8)
ALU_ADD_X:
...
jmp *(%r12, %rax, 8)
The jumptable address is placed in a register once, at the beginning of
the function. The function execution can then go through multiple
indirect jumps which rely on that same register value. This has a few
issues:
1) Objtool isn't smart enough to be able to track such a register value
across multiple recursive indirect jumps through the jump table.
2) With CONFIG_RETPOLINE enabled, this optimization actually results in
a small slowdown. I measured a ~4.7% slowdown in the test_bpf
"tcpdump port 22" selftest.
This slowdown is actually predicted by the GCC manual:
Note: When compiling a program using computed gotos, a GCC
extension, you may get better run-time performance if you
disable the global common subexpression elimination pass by
adding -fno-gcse to the command line.
So just disable the optimization for this function.
Fixes: e55a73251d ("bpf: Fix ORC unwinding in non-JIT BPF code")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/30c3ca29ba037afcbd860a8672eef0021addf9fe.1563413318.git.jpoimboe@redhat.com
- Add user space specific memory reading for kprobes
- Allow kprobes to be executed earlier in boot
The rest are mostly just various clean ups and small fixes.
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Merge tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"The main changes in this release include:
- Add user space specific memory reading for kprobes
- Allow kprobes to be executed earlier in boot
The rest are mostly just various clean ups and small fixes"
* tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
tracing: Make trace_get_fields() global
tracing: Let filter_assign_type() detect FILTER_PTR_STRING
tracing: Pass type into tracing_generic_entry_update()
ftrace/selftest: Test if set_event/ftrace_pid exists before writing
ftrace/selftests: Return the skip code when tracing directory not configured in kernel
tracing/kprobe: Check registered state using kprobe
tracing/probe: Add trace_event_call accesses APIs
tracing/probe: Add probe event name and group name accesses APIs
tracing/probe: Add trace flag access APIs for trace_probe
tracing/probe: Add trace_event_file access APIs for trace_probe
tracing/probe: Add trace_event_call register API for trace_probe
tracing/probe: Add trace_probe init and free functions
tracing/uprobe: Set print format when parsing command
tracing/kprobe: Set print format right after parsed command
kprobes: Fix to init kprobes in subsys_initcall
tracepoint: Use struct_size() in kmalloc()
ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS
ftrace: Enable trampoline when rec count returns back to one
tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline
tracing: Make a separate config for trace event self tests
...
Pull swiotlb updates from Konrad Rzeszutek Wilk:
"One compiler fix, and a bug-fix in swiotlb_nr_tbl() and
swiotlb_max_segment() to check also for no_iotlb_memory"
* 'for-linus-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
swiotlb: fix phys_addr_t overflow warning
swiotlb: Return consistent SWIOTLB segments/nr_tbl
swiotlb: Group identical cleanup in swiotlb_cleanup()
When walking userspace stacks, USER_DS needs to be set, otherwise
access_ok() will not function as expected.
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Reported-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vegard Nossum <vegard.nossum@oracle.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lkml.kernel.org/r/20190718085754.GM3402@hirez.programming.kicks-ass.net
Testing padata with the tcrypt module on a 5.2 kernel...
# modprobe tcrypt alg="pcrypt(rfc4106(gcm(aes)))" type=3
# modprobe tcrypt mode=211 sec=1
...produces this splat:
INFO: task modprobe:10075 blocked for more than 120 seconds.
Not tainted 5.2.0-base+ #16
modprobe D 0 10075 10064 0x80004080
Call Trace:
? __schedule+0x4dd/0x610
? ring_buffer_unlock_commit+0x23/0x100
schedule+0x6c/0x90
schedule_timeout+0x3b/0x320
? trace_buffer_unlock_commit_regs+0x4f/0x1f0
wait_for_common+0x160/0x1a0
? wake_up_q+0x80/0x80
{ crypto_wait_req } # entries in braces added by hand
{ do_one_aead_op }
{ test_aead_jiffies }
test_aead_speed.constprop.17+0x681/0xf30 [tcrypt]
do_test+0x4053/0x6a2b [tcrypt]
? 0xffffffffa00f4000
tcrypt_mod_init+0x50/0x1000 [tcrypt]
...
The second modprobe command never finishes because in padata_reorder,
CPU0's load of reorder_objects is executed before the unlocking store in
spin_unlock_bh(pd->lock), causing CPU0 to miss CPU1's increment:
CPU0 CPU1
padata_reorder padata_do_serial
LOAD reorder_objects // 0
INC reorder_objects // 1
padata_reorder
TRYLOCK pd->lock // failed
UNLOCK pd->lock
CPU0 deletes the timer before returning from padata_reorder and since no
other job is submitted to padata, modprobe waits indefinitely.
Add a pair of full barriers to guarantee proper ordering:
CPU0 CPU1
padata_reorder padata_do_serial
UNLOCK pd->lock
smp_mb()
LOAD reorder_objects
INC reorder_objects
smp_mb__after_atomic()
padata_reorder
TRYLOCK pd->lock
smp_mb__after_atomic is needed so the read part of the trylock operation
comes after the INC, as Andrea points out. Thanks also to Andrea for
help with writing a litmus test.
Fixes: 16295bec63 ("padata: Generic parallelization/serialization interface")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: <stable@vger.kernel.org>
Cc: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Merge more updates from Andrew Morton:
"VM:
- z3fold fixes and enhancements by Henry Burns and Vitaly Wool
- more accurate reclaimed slab caches calculations by Yafang Shao
- fix MAP_UNINITIALIZED UAPI symbol to not depend on config, by
Christoph Hellwig
- !CONFIG_MMU fixes by Christoph Hellwig
- new novmcoredd parameter to omit device dumps from vmcore, by
Kairui Song
- new test_meminit module for testing heap and pagealloc
initialization, by Alexander Potapenko
- ioremap improvements for huge mappings, by Anshuman Khandual
- generalize kprobe page fault handling, by Anshuman Khandual
- device-dax hotplug fixes and improvements, by Pavel Tatashin
- enable synchronous DAX fault on powerpc, by Aneesh Kumar K.V
- add pte_devmap() support for arm64, by Robin Murphy
- unify locked_vm accounting with a helper, by Daniel Jordan
- several misc fixes
core/lib:
- new typeof_member() macro including some users, by Alexey Dobriyan
- make BIT() and GENMASK() available in asm, by Masahiro Yamada
- changed LIST_POISON2 on x86_64 to 0xdead000000000122 for better
code generation, by Alexey Dobriyan
- rbtree code size optimizations, by Michel Lespinasse
- convert struct pid count to refcount_t, by Joel Fernandes
get_maintainer.pl:
- add --no-moderated switch to skip moderated ML's, by Joe Perches
misc:
- ptrace PTRACE_GET_SYSCALL_INFO interface
- coda updates
- gdb scripts, various"
[ Using merge message suggestion from Vlastimil Babka, with some editing - Linus ]
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (100 commits)
fs/select.c: use struct_size() in kmalloc()
mm: add account_locked_vm utility function
arm64: mm: implement pte_devmap support
mm: introduce ARCH_HAS_PTE_DEVMAP
mm: clean up is_device_*_page() definitions
mm/mmap: move common defines to mman-common.h
mm: move MAP_SYNC to asm-generic/mman-common.h
device-dax: "Hotremove" persistent memory that is used like normal RAM
mm/hotplug: make remove_memory() interface usable
device-dax: fix memory and resource leak if hotplug fails
include/linux/lz4.h: fix spelling and copy-paste errors in documentation
ipc/mqueue.c: only perform resource calculation if user valid
include/asm-generic/bug.h: fix "cut here" for WARN_ON for __WARN_TAINT architectures
scripts/gdb: add helpers to find and list devices
scripts/gdb: add lx-genpd-summary command
drivers/pps/pps.c: clear offset flags in PPS_SETPARAMS ioctl
kernel/pid.c: convert struct pid count to refcount_t
drivers/rapidio/devices/rio_mport_cdev.c: NUL terminate some strings
select: shift restore_saved_sigmask_unless() into poll_select_copy_remaining()
select: change do_poll() to return -ERESTARTNOHAND rather than -EINTR
...
Don't just check for a swiotlb buffer, but also if buffering might
be required for this particular device.
Fixes: 133d624b1c ("dma: Introduce dma_max_mapping_size()")
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
struct pid's count is an atomic_t field used as a refcount. Use
refcount_t for it which is basically atomic_t but does additional
checking to prevent use-after-free bugs.
For memory ordering, the only change is with the following:
- if ((atomic_read(&pid->count) == 1) ||
- atomic_dec_and_test(&pid->count)) {
+ if (refcount_dec_and_test(&pid->count)) {
kmem_cache_free(ns->pid_cachep, pid);
Here the change is from: Fully ordered --> RELEASE + ACQUIRE (as per
refcount-vs-atomic.rst) This ACQUIRE should take care of making sure the
free happens after the refcount_dec_and_test().
The above hunk also removes atomic_read() since it is not needed for the
code to work and it is unclear how beneficial it is. The removal lets
refcount_dec_and_test() check for cases where get_pid() happened before
the object was freed.
Link: http://lkml.kernel.org/r/20190701183826.191936-1-joel@joelfernandes.org
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Elena Reshetova <elena.reshetova@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: KJ Tsanaktsidis <ktsanaktsidis@zendesk.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
task->saved_sigmask and ->restore_sigmask are only used in the ret-from-
syscall paths. This means that set_user_sigmask() can save ->blocked in
->saved_sigmask and do set_restore_sigmask() to indicate that ->blocked
was modified.
This way the callers do not need 2 sigset_t's passed to set/restore and
restore_user_sigmask() renamed to restore_saved_sigmask_unless() turns
into the trivial helper which just calls restore_saved_sigmask().
Link: http://lkml.kernel.org/r/20190606113206.GA9464@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Eric Wong <e@80x24.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: David Laight <David.Laight@aculab.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PTRACE_GET_SYSCALL_INFO is a generic ptrace API that lets ptracer obtain
details of the syscall the tracee is blocked in.
There are two reasons for a special syscall-related ptrace request.
Firstly, with the current ptrace API there are cases when ptracer cannot
retrieve necessary information about syscalls. Some examples include:
* The notorious int-0x80-from-64-bit-task issue. See [1] for details.
In short, if a 64-bit task performs a syscall through int 0x80, its
tracer has no reliable means to find out that the syscall was, in
fact, a compat syscall, and misidentifies it.
* Syscall-enter-stop and syscall-exit-stop look the same for the
tracer. Common practice is to keep track of the sequence of
ptrace-stops in order not to mix the two syscall-stops up. But it is
not as simple as it looks; for example, strace had a (just recently
fixed) long-standing bug where attaching strace to a tracee that is
performing the execve system call led to the tracer identifying the
following syscall-exit-stop as syscall-enter-stop, which messed up
all the state tracking.
* Since the introduction of commit 84d77d3f06 ("ptrace: Don't allow
accessing an undumpable mm"), both PTRACE_PEEKDATA and
process_vm_readv become unavailable when the process dumpable flag is
cleared. On such architectures as ia64 this results in all syscall
arguments being unavailable for the tracer.
Secondly, ptracers also have to support a lot of arch-specific code for
obtaining information about the tracee. For some architectures, this
requires a ptrace(PTRACE_PEEKUSER, ...) invocation for every syscall
argument and return value.
ptrace(2) man page:
long ptrace(enum __ptrace_request request, pid_t pid,
void *addr, void *data);
...
PTRACE_GET_SYSCALL_INFO
Retrieve information about the syscall that caused the stop.
The information is placed into the buffer pointed by "data"
argument, which should be a pointer to a buffer of type
"struct ptrace_syscall_info".
The "addr" argument contains the size of the buffer pointed to
by "data" argument (i.e., sizeof(struct ptrace_syscall_info)).
The return value contains the number of bytes available
to be written by the kernel.
If the size of data to be written by the kernel exceeds the size
specified by "addr" argument, the output is truncated.
[ldv@altlinux.org: selftests/seccomp/seccomp_bpf: update for PTRACE_GET_SYSCALL_INFO]
Link: http://lkml.kernel.org/r/20190708182904.GA12332@altlinux.org
Link: http://lkml.kernel.org/r/20190510152842.GF28558@altlinux.org
Signed-off-by: Elvira Khabirova <lineprinter@altlinux.org>
Co-developed-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Eugene Syromyatnikov <esyr@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Helge Deller <deller@gmx.de> [parisc]
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: kbuild test robot <lkp@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a device doesn't support DMA to a physical address that includes the
encryption bit (currently bit 47, so 48-bit DMA), then the DMA must
occur to unencrypted memory. SWIOTLB is used to satisfy that requirement
if an IOMMU is not active (enabled or configured in passthrough mode).
However, commit fafadcd165 ("swiotlb: don't dip into swiotlb pool for
coherent allocations") modified the coherent allocation support in
SWIOTLB to use the DMA direct coherent allocation support. When an IOMMU
is not active, this resulted in dma_alloc_coherent() failing for devices
that didn't support DMA addresses that included the encryption bit.
Addressing this requires changes to the force_dma_unencrypted() function
in kernel/dma/direct.c. Since the function is now non-trivial and
SME/SEV specific, update the DMA direct support to add an arch override
for the force_dma_unencrypted() function. The arch override is selected
when CONFIG_AMD_MEM_ENCRYPT is set. The arch override function resides in
the arch/x86/mm/mem_encrypt.c file and forces unencrypted DMA when either
SEV is active or SME is active and the device does not support DMA to
physical addresses that include the encryption bit.
Fixes: fafadcd165 ("swiotlb: don't dip into swiotlb pool for coherent allocations")
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
[hch: moved the force_dma_unencrypted declaration to dma-mapping.h,
fold the s390 fix from Halil Pasic]
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Merge tag 'docs/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull rst conversion of docs from Mauro Carvalho Chehab:
"As agreed with Jon, I'm sending this big series directly to you, c/c
him, as this series required a special care, in order to avoid
conflicts with other trees"
* tag 'docs/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (77 commits)
docs: kbuild: fix build with pdf and fix some minor issues
docs: block: fix pdf output
docs: arm: fix a breakage with pdf output
docs: don't use nested tables
docs: gpio: add sysfs interface to the admin-guide
docs: locking: add it to the main index
docs: add some directories to the main documentation index
docs: add SPDX tags to new index files
docs: add a memory-devices subdir to driver-api
docs: phy: place documentation under driver-api
docs: serial: move it to the driver-api
docs: driver-api: add remaining converted dirs to it
docs: driver-api: add xilinx driver API documentation
docs: driver-api: add a series of orphaned documents
docs: admin-guide: add a series of orphaned documents
docs: cgroup-v1: add it to the admin-guide book
docs: aoe: add it to the driver-api book
docs: add some documentation dirs to the driver-api book
docs: driver-model: move it to the driver-api book
docs: lp855x-driver.rst: add it to the driver-api book
...
