Commit Graph

31467 Commits

Author SHA1 Message Date
Liang, Kan
d44f821b0e perf/core: Optimize perf_init_event() for TYPE_SOFTWARE
Andi reported that he was hitting the linear search in
perf_init_event() a lot. Now that all !TYPE_SOFTWARE events should hit
the IDR, make sure the TYPE_SOFTWARE events are at the head of the
list such that we'll quickly find the right PMU (provided a valid
event was given).

Signed-off-by: Liang, Kan <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.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: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-28 12:53:28 +01:00
Peter Zijlstra
66d258c5b0 perf/core: Optimize perf_init_event()
Andi reported that he was hitting the linear search in
perf_init_event() a lot. Make more agressive use of the IDR lookup to
avoid hitting the linear search.

With exception of PERF_TYPE_SOFTWARE (which relies on a hideous hack),
we can put everything in the IDR. On top of that, we can alias
TYPE_HARDWARE and TYPE_HW_CACHE to TYPE_RAW on the lookup side.

This greatly reduces the chances of hitting the linear search.

Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan <kan.liang@linux.intel.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: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-28 12:51:02 +01:00
Peter Zijlstra
db0503e4f6 perf/core: Optimize perf_install_in_event()
Andi reported that when creating a lot of events, a lot of time is
spent in IPIs and asked if it would be possible to elide some of that.

Now when, as for example the perf-tool always does, events are created
disabled, then these events will not need to be scheduled when added
to the context (they're still disable) and therefore the IPI is not
required -- except for the very first event, that will need to set
ctx->is_active.

( It might be possible to set ctx->is_active remotely for cpu_ctx, but
  we really need the IPI for task_ctx, so lets not make that
  distinction. )

Also use __perf_effective_state() since group events depend on the
state of the leader, if the leader is OFF, the whole group is OFF.

So when sibling events are created enabled (XXX check tool) then we
only need a single IPI to create and enable the whole group (+ that
initial IPI to initialize the context).

Suggested-by: Andi Kleen <andi@firstfloor.org>
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.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: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-28 12:51:02 +01:00
Alexey Budankov
c2b98a8661 perf/x86: Synchronize PMU task contexts on optimized context switches
Install Intel specific PMU task context synchronization adapter and
extend optimized context switch path with PMU specific task context
synchronization to fix LBR callstack virtualization on context switches.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.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: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lkml.kernel.org/r/9c6445a9-bdba-ef03-3859-f1f91198f27a@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-28 12:51:01 +01:00
Ingo Molnar
65133033ee Merge branch 'perf/urgent' into perf/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-28 12:38:26 +01:00
Alexander Shishkin
8c7e975667 perf/core: Start rejecting the syscall with attr.__reserved_2 set
Commit:

  1a59413124 ("perf: Add wakeup watermark control to the AUX area")

added attr.__reserved_2 padding, but forgot to add an ABI check to reject
attributes with this field set. Fix that.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: adrian.hunter@intel.com
Cc: mathieu.poirier@linaro.org
Link: https://lkml.kernel.org/r/20191025121636.75182-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-28 11:01:59 +01:00
Linus Torvalds
2b776b54bc Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
 "A small set of fixes for time(keeping):

   - Add a missing include to prevent compiler warnings.

   - Make the VDSO implementation of clock_getres() POSIX compliant
     again. A recent change dropped the NULL pointer guard which is
     required as NULL is a valid pointer value for this function.

   - Fix two function documentation typos"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-cpu-timers: Fix two trivial comments
  timers/sched_clock: Include local timekeeping.h for missing declarations
  lib/vdso: Make clock_getres() POSIX compliant again
2019-10-27 07:04:22 -04:00
Linus Torvalds
a8a31fdcca Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 "A set of perf fixes:

  kernel:

   - Unbreak the tracking of auxiliary buffer allocations which got
     imbalanced causing recource limit failures.

   - Fix the fallout of splitting of ToPA entries which missed to shift
     the base entry PA correctly.

   - Use the correct context to lookup the AUX event when unmapping the
     associated AUX buffer so the event can be stopped and the buffer
     reference dropped.

  tools:

   - Fix buildiid-cache mode setting in copyfile_mode_ns() when copying
     /proc/kcore

   - Fix freeing id arrays in the event list so the correct event is
     closed.

   - Sync sched.h anc kvm.h headers with the kernel sources.

   - Link jvmti against tools/lib/ctype.o to have weak strlcpy().

   - Fix multiple memory and file descriptor leaks, found by coverity in
     perf annotate.

   - Fix leaks in error handling paths in 'perf c2c', 'perf kmem', found
     by a static analysis tool"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/aux: Fix AUX output stopping
  perf/aux: Fix tracking of auxiliary trace buffer allocation
  perf/x86/intel/pt: Fix base for single entry topa
  perf kmem: Fix memory leak in compact_gfp_flags()
  tools headers UAPI: Sync sched.h with the kernel
  tools headers kvm: Sync kvm.h headers with the kernel sources
  tools headers kvm: Sync kvm headers with the kernel sources
  tools headers kvm: Sync kvm headers with the kernel sources
  perf c2c: Fix memory leak in build_cl_output()
  perf tools: Fix mode setting in copyfile_mode_ns()
  perf annotate: Fix multiple memory and file descriptor leaks
  perf tools: Fix resource leak of closedir() on the error paths
  perf evlist: Fix fix for freed id arrays
  perf jvmti: Link against tools/lib/ctype.h to have weak strlcpy()
2019-10-27 06:59:34 -04:00
Linus Torvalds
5fa2845fd7 Power management fixes for 5.4-rc5
- Using device PM QoS of CPU devices for managing frequency limits
    in cpufreq does not work, so introduce frequency QoS (based on the
    original low-level PM QoS) for this purpose, switch cpufreq and
    related code over to using it and fix a race involving deferred
    updates of frequency limits on top of that (Rafael Wysocki, Sudeep
    Holla).
 
  - Avoid calling regulator_enable()/disable() from the OPP framework
    to avoid side-effects on boot-enabled regulators that may change their
    initial voltage due to performing initial voltage balancing without
    all restrictions from the consumers (Marek Szyprowski).
 
  - Avoid a kref management issue in the OPP library code and drop an
    incorrectly added lockdep_assert_held() from it (Viresh Kumar).
 
  - Make the recently added haltpoll cpuidle driver take the 'idle='
    override into account as appropriate (Zhenzhong Duan).
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAl2x2nUSHHJqd0Byand5
 c29ja2kubmV0AAoJEILEb/54YlRxB+wP/iwugVCQKNGaOiPRLz3SlL/hchZ7Nhye
 qqetgC5dP/ZUkLrvJnt31wTgpF3VA9AQzuydtSEc76sf/hwaVhmyKhUC8TqqYYx1
 Vhu6EE2tEtFyBNNl0ZPJS8+q7AjhSrDSV8JyFBafOfxRJV2za2Q+Fl0P4Y6gzcez
 mYC1Ol7Of9c8L9J2p33ViNh31AQR8LnqV8YhIZRG5F4+jklJIlEt8QL0C25VQYAX
 9TLhLrXktPRPJytX2eOU8vHOmVAz5qKvU3S6mAPhVPpnEcZL9E56H1sc3xCpX0ww
 V8pnteMOxa3RUySTlGwnzKRwZQ7eSQjsJO9s/YWT+EGzt58Gr0q2WnEiZ8Vm38Hg
 /eOWsyxZiS0JYGc9+Gg/Hh2XFmMxX5QEaKlyIyuJbXvwGGm8gg02MNziXa1FmUd+
 nuklYhN8MJjH1iV84V3c0M8sdrut7LOlOotzyDniZWj7L57Ht+MWNSbpDoebPdGb
 mhOYv/wjXcek0m8mHtlT6w/5o3qDYEkAsosacH6Eko/11tHCfnCGT/no/3ILf3f+
 bBCVxXhkNFdSGC6RcozO1TrMbG3PN9nCzq+od+BDUOmqfsjR8vJbSwbHUQaWn0DU
 jIBASI2FXlN6Hi3SMFA4m7Scnz1fwL9vUVT4EIJ6U5dsVx+T0qDIbgZ3nzyvp5Tn
 vt6X4VzAZ5d/
 =yitK
 -----END PGP SIGNATURE-----

Merge tag 'pm-5.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix problems related to frequency limits management in cpufreq
  that were introduced during the 5.3 cycle (when PM QoS had started to
  be used for that), fix a few issues in the OPP (operating performance
  points) library code and fix up the recently added haltpoll cpuidle
  driver.

  The cpufreq changes are somewhat bigger that I would like them to be
  at this stage of the cycle, but the problems fixed by them include
  crashes on boot and shutdown in some cases (among other things) and in
  my view it is better to address the root of the issue right away.

  Specifics:

   - Using device PM QoS of CPU devices for managing frequency limits in
     cpufreq does not work, so introduce frequency QoS (based on the
     original low-level PM QoS) for this purpose, switch cpufreq and
     related code over to using it and fix a race involving deferred
     updates of frequency limits on top of that (Rafael Wysocki, Sudeep
     Holla).

   - Avoid calling regulator_enable()/disable() from the OPP framework
     to avoid side-effects on boot-enabled regulators that may change
     their initial voltage due to performing initial voltage balancing
     without all restrictions from the consumers (Marek Szyprowski).

   - Avoid a kref management issue in the OPP library code and drop an
     incorrectly added lockdep_assert_held() from it (Viresh Kumar).

   - Make the recently added haltpoll cpuidle driver take the 'idle='
     override into account as appropriate (Zhenzhong Duan)"

* tag 'pm-5.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  opp: Reinitialize the list_kref before adding the static OPPs again
  cpufreq: Cancel policy update work scheduled before freeing
  cpuidle: haltpoll: Take 'idle=' override into account
  opp: core: Revert "add regulators enable and disable"
  PM: QoS: Drop frequency QoS types from device PM QoS
  cpufreq: Use per-policy frequency QoS
  PM: QoS: Introduce frequency QoS
  opp: of: drop incorrect lockdep_assert_held()
2019-10-24 15:36:11 -04:00
Linus Torvalds
fa8a74de06 Two minor fixes:
- A race in perf trace initialization (missing mutexes)
 
  - Minor fix to represent gfp_t in synthetic events as properly signed
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXa5C9hQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qrFqAP9FskyS8xr1iqquWGarC38jYaLg8C2c
 7ou+tdIm+Rez5QEA+3E456Esusmx3dACk2QLeb788Pf1wQOjKXyZ9H+2eAE=
 =ys+Y
 -----END PGP SIGNATURE-----

Merge tag 'trace-v5.4-rc3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Two minor fixes:

   - A race in perf trace initialization (missing mutexes)

   - Minor fix to represent gfp_t in synthetic events as properly
     signed"

* tag 'trace-v5.4-rc3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix race in perf_trace_buf initialization
  tracing: Fix "gfp_t" format for synthetic events
2019-10-23 15:43:51 -04:00
Yi Wang
7f2cbcbcaf posix-cpu-timers: Fix two trivial comments
Recent changes modified the function arguments of
thread_group_sample_cputime() and task_cputimers_expired(), but forgot to
update the comments. Fix it up.

[ tglx: Changed the argument name of task_cputimers_expired() as the pointer
  	points to an array of samples. ]

Fixes: b7be4ef136 ("posix-cpu-timers: Switch thread group sampling to array")
Fixes: 001f797143 ("posix-cpu-timers: Make expiry checks array based")
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1571643852-21848-1-git-send-email-wang.yi59@zte.com.cn
2019-10-23 14:48:24 +02:00
Ben Dooks (Codethink)
086ee46b08 timers/sched_clock: Include local timekeeping.h for missing declarations
Include the timekeeping.h header to get the declaration of the
sched_clock_{suspend,resume} functions. Fixes the following sparse
warnings:

kernel/time/sched_clock.c:275:5: warning: symbol 'sched_clock_suspend' was not declared. Should it be static?
kernel/time/sched_clock.c:286:6: warning: symbol 'sched_clock_resume' was not declared. Should it be static?

Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191022131226.11465-1-ben.dooks@codethink.co.uk
2019-10-23 14:48:23 +02:00
Alexander Shishkin
f3a519e4ad perf/aux: Fix AUX output stopping
Commit:

  8a58ddae23 ("perf/core: Fix exclusive events' grouping")

allows CAP_EXCLUSIVE events to be grouped with other events. Since all
of those also happen to be AUX events (which is not the case the other
way around, because arch/s390), this changes the rules for stopping the
output: the AUX event may not be on its PMU's context any more, if it's
grouped with a HW event, in which case it will be on that HW event's
context instead. If that's the case, munmap() of the AUX buffer can't
find and stop the AUX event, potentially leaving the last reference with
the atomic context, which will then end up freeing the AUX buffer. This
will then trip warnings:

Fix this by using the context's PMU context when looking for events
to stop, instead of the event's PMU context.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20191022073940.61814-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-22 14:39:37 +02:00
Prateek Sood
6b1340cc00 tracing: Fix race in perf_trace_buf initialization
A race condition exists while initialiazing perf_trace_buf from
perf_trace_init() and perf_kprobe_init().

      CPU0                                        CPU1
perf_trace_init()
  mutex_lock(&event_mutex)
    perf_trace_event_init()
      perf_trace_event_reg()
        total_ref_count == 0
	buf = alloc_percpu()
        perf_trace_buf[i] = buf
        tp_event->class->reg() //fails       perf_kprobe_init()
	goto fail                              perf_trace_event_init()
                                                 perf_trace_event_reg()
        fail:
	  total_ref_count == 0

                                                   total_ref_count == 0
                                                   buf = alloc_percpu()
                                                   perf_trace_buf[i] = buf
                                                   tp_event->class->reg()
                                                   total_ref_count++

          free_percpu(perf_trace_buf[i])
          perf_trace_buf[i] = NULL

Any subsequent call to perf_trace_event_reg() will observe total_ref_count > 0,
causing the perf_trace_buf to be always NULL. This can result in perf_trace_buf
getting accessed from perf_trace_buf_alloc() without being initialized. Acquiring
event_mutex in perf_kprobe_init() before calling perf_trace_event_init() should
fix this race.

The race caused the following bug:

 Unable to handle kernel paging request at virtual address 0000003106f2003c
 Mem abort info:
   ESR = 0x96000045
   Exception class = DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
 Data abort info:
   ISV = 0, ISS = 0x00000045
   CM = 0, WnR = 1
 user pgtable: 4k pages, 39-bit VAs, pgdp = ffffffc034b9b000
 [0000003106f2003c] pgd=0000000000000000, pud=0000000000000000
 Internal error: Oops: 96000045 [#1] PREEMPT SMP
 Process syz-executor (pid: 18393, stack limit = 0xffffffc093190000)
 pstate: 80400005 (Nzcv daif +PAN -UAO)
 pc : __memset+0x20/0x1ac
 lr : memset+0x3c/0x50
 sp : ffffffc09319fc50

  __memset+0x20/0x1ac
  perf_trace_buf_alloc+0x140/0x1a0
  perf_trace_sys_enter+0x158/0x310
  syscall_trace_enter+0x348/0x7c0
  el0_svc_common+0x11c/0x368
  el0_svc_handler+0x12c/0x198
  el0_svc+0x8/0xc

Ramdumps showed the following:
  total_ref_count = 3
  perf_trace_buf = (
      0x0 -> NULL,
      0x0 -> NULL,
      0x0 -> NULL,
      0x0 -> NULL)

Link: http://lkml.kernel.org/r/1571120245-4186-1-git-send-email-prsood@codeaurora.org

Cc: stable@vger.kernel.org
Fixes: e12f03d703 ("perf/core: Implement the 'perf_kprobe' PMU")
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-21 19:38:28 -04:00
Ingo Molnar
aa7a7b7297 Merge branch 'perf/urgent' into perf/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-22 01:15:32 +02:00
Thomas Richter
5e6c3c7b1e perf/aux: Fix tracking of auxiliary trace buffer allocation
The following commit from the v5.4 merge window:

  d44248a413 ("perf/core: Rework memory accounting in perf_mmap()")

... breaks auxiliary trace buffer tracking.

If I run command 'perf record -e rbd000' to record samples and saving
them in the **auxiliary** trace buffer then the value of 'locked_vm' becomes
negative after all trace buffers have been allocated and released:

During allocation the values increase:

  [52.250027] perf_mmap user->locked_vm:0x87 pinned_vm:0x0 ret:0
  [52.250115] perf_mmap user->locked_vm:0x107 pinned_vm:0x0 ret:0
  [52.250251] perf_mmap user->locked_vm:0x188 pinned_vm:0x0 ret:0
  [52.250326] perf_mmap user->locked_vm:0x208 pinned_vm:0x0 ret:0
  [52.250441] perf_mmap user->locked_vm:0x289 pinned_vm:0x0 ret:0
  [52.250498] perf_mmap user->locked_vm:0x309 pinned_vm:0x0 ret:0
  [52.250613] perf_mmap user->locked_vm:0x38a pinned_vm:0x0 ret:0
  [52.250715] perf_mmap user->locked_vm:0x408 pinned_vm:0x2 ret:0
  [52.250834] perf_mmap user->locked_vm:0x408 pinned_vm:0x83 ret:0
  [52.250915] perf_mmap user->locked_vm:0x408 pinned_vm:0x103 ret:0
  [52.251061] perf_mmap user->locked_vm:0x408 pinned_vm:0x184 ret:0
  [52.251146] perf_mmap user->locked_vm:0x408 pinned_vm:0x204 ret:0
  [52.251299] perf_mmap user->locked_vm:0x408 pinned_vm:0x285 ret:0
  [52.251383] perf_mmap user->locked_vm:0x408 pinned_vm:0x305 ret:0
  [52.251544] perf_mmap user->locked_vm:0x408 pinned_vm:0x386 ret:0
  [52.251634] perf_mmap user->locked_vm:0x408 pinned_vm:0x406 ret:0
  [52.253018] perf_mmap user->locked_vm:0x408 pinned_vm:0x487 ret:0
  [52.253197] perf_mmap user->locked_vm:0x408 pinned_vm:0x508 ret:0
  [52.253374] perf_mmap user->locked_vm:0x408 pinned_vm:0x589 ret:0
  [52.253550] perf_mmap user->locked_vm:0x408 pinned_vm:0x60a ret:0
  [52.253726] perf_mmap user->locked_vm:0x408 pinned_vm:0x68b ret:0
  [52.253903] perf_mmap user->locked_vm:0x408 pinned_vm:0x70c ret:0
  [52.254084] perf_mmap user->locked_vm:0x408 pinned_vm:0x78d ret:0
  [52.254263] perf_mmap user->locked_vm:0x408 pinned_vm:0x80e ret:0

The value of user->locked_vm increases to a limit then the memory
is tracked by pinned_vm.

During deallocation the size is subtracted from pinned_vm until
it hits a limit. Then a larger value is subtracted from locked_vm
leading to a large number (because of type unsigned):

  [64.267797] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x78d
  [64.267826] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x70c
  [64.267848] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x68b
  [64.267869] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x60a
  [64.267891] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x589
  [64.267911] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x508
  [64.267933] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x487
  [64.267952] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x406
  [64.268883] perf_mmap_close mmap_user->locked_vm:0x307 pinned_vm:0x406
  [64.269117] perf_mmap_close mmap_user->locked_vm:0x206 pinned_vm:0x406
  [64.269433] perf_mmap_close mmap_user->locked_vm:0x105 pinned_vm:0x406
  [64.269536] perf_mmap_close mmap_user->locked_vm:0x4 pinned_vm:0x404
  [64.269797] perf_mmap_close mmap_user->locked_vm:0xffffffffffffff84 pinned_vm:0x303
  [64.270105] perf_mmap_close mmap_user->locked_vm:0xffffffffffffff04 pinned_vm:0x202
  [64.270374] perf_mmap_close mmap_user->locked_vm:0xfffffffffffffe84 pinned_vm:0x101
  [64.270628] perf_mmap_close mmap_user->locked_vm:0xfffffffffffffe04 pinned_vm:0x0

This value sticks for the user until system is rebooted, causing
follow-on system calls using locked_vm resource limit to fail.

Note: There is no issue using the normal trace buffer.

In fact the issue is in perf_mmap_close(). During allocation auxiliary
trace buffer memory is either traced as 'extra' and added to 'pinned_vm'
or trace as 'user_extra' and added to 'locked_vm'. This applies for
normal trace buffers and auxiliary trace buffer.

However in function perf_mmap_close() all auxiliary trace buffer is
subtraced from 'locked_vm' and never from 'pinned_vm'. This breaks the
ballance.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.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: acme@kernel.org
Cc: gor@linux.ibm.com
Cc: hechaol@fb.com
Cc: heiko.carstens@de.ibm.com
Cc: linux-perf-users@vger.kernel.org
Cc: songliubraving@fb.com
Fixes: d44248a413 ("perf/core: Rework memory accounting in perf_mmap()")
Link: https://lkml.kernel.org/r/20191021083354.67868-1-tmricht@linux.ibm.com
[ Minor readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-21 11:31:24 +02:00
Rafael J. Wysocki
77751a466e PM: QoS: Introduce frequency QoS
Introduce frequency QoS, based on the "raw" low-level PM QoS, to
represent min and max frequency requests and aggregate constraints.

The min and max frequency requests are to be represented by
struct freq_qos_request objects and the aggregate constraints are to
be represented by struct freq_constraints objects.  The latter are
expected to be initialized with the help of freq_constraints_init().

The freq_qos_read_value() helper is defined to retrieve the aggregate
constraints values from a given struct freq_constraints object and
there are the freq_qos_add_request(), freq_qos_update_request() and
freq_qos_remove_request() helpers to manipulate the min and max
frequency requests.  It is assumed that the the helpers will not
run concurrently with each other for the same struct freq_qos_request
object, so if that may be the case, their uses must ensure proper
synchronization between them (e.g. through locking).

In addition, freq_qos_add_notifier() and freq_qos_remove_notifier()
are provided to add and remove notifiers that will trigger on aggregate
constraint changes to and from a given struct freq_constraints object,
respectively.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-10-21 02:05:21 +02:00
Linus Torvalds
e2ab4ef83f Kbuild fixes for v5.4 (2nd)
- fix a bashism of setlocalversion
 
  - do not use the too new --sort option of tar
 -----BEGIN PGP SIGNATURE-----
 
 iQJSBAABCgA8FiEEbmPs18K1szRHjPqEPYsBB53g2wYFAl2sh9MeHHlhbWFkYS5t
 YXNhaGlyb0Bzb2Npb25leHQuY29tAAoJED2LAQed4NsGO90P/13dNgaibb3JcCvp
 +ugn+o26V+aqZ8uDLPPifUNFLLnDfGmgORAOe0Z2mGI2CqMDaWMYjvyZNF1KzOdD
 +WFZubiTUevYyM9AOG6O6EOGEDRumgvdNhnJIP+aCUNKGM50zzhuAa23y6Xip1NZ
 qJY5AYu9KiH9jTXtZAdGReuMdvNRsMZuvmI4Qnc21utItVxDFEQKGdTlRoJaGEdN
 Zc/f1HzWwlr7VWZiy0iMRSCAAtAA3TN3S1bw5QCYsuJb3LRl2EIOKMeSinRTYWRc
 zU5CHrkRSX4/M/o8VantTOZueuGMfbaOAl1KEDh8DUPDcrl+gmL4s8aFuDW+5d2+
 7pPlEe/FNZOAGVBDgiK59N3bl2Rn/Uyg9VGwFc8PU3VeY5VbS97ayBaLFcua2zwX
 88mtsZoq+fN3qsq8gfbb21qauTbEibyrk8lzjHoQl07TW82GFWG/GXSt9dQAm1sb
 w/M15WdaONKOzkYXGGCo0l6vdXx1+qqV/LZQcaWhfcoeU5YVVEmSRwCakCxxSWUE
 rvWtn0vljgH8kyb0gnUP6qLJC9clwMv58sl/mG65/D7zs9B74g16BkX0tU8vLSpr
 Ww1BpGtPwuFPp7+kEzWemtlulhDvow2xIX7bNIkAk1IIVpyCmU98AKpivR7G9Cvt
 4cZPSGRU+s2ou/hrtjryzvmwhGUG
 =KNWF
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-fixes-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull more Kbuild fixes from Masahiro Yamada:

 - fix a bashism of setlocalversion

 - do not use the too new --sort option of tar

* tag 'kbuild-fixes-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kheaders: substituting --sort in archive creation
  scripts: setlocalversion: fix a bashism
  kbuild: update comment about KBUILD_ALLDIRS
2019-10-20 12:36:57 -04:00
Linus Torvalds
188768f3c0 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull hrtimer fixlet from Thomas Gleixner:
 "A single commit annotating the lockcless access to timer->base with
  READ_ONCE() and adding the WRITE_ONCE() counterparts for completeness"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Annotate lockless access to timer->base
2019-10-20 06:25:12 -04:00
Linus Torvalds
589f1222e0 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull stop-machine fix from Thomas Gleixner:
 "A single fix, amending stop machine with WRITE/READ_ONCE() to address
  the fallout of KCSAN"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  stop_machine: Avoid potential race behaviour
2019-10-20 06:22:25 -04:00
Song Liu
aa5de305c9 kernel/events/uprobes.c: only do FOLL_SPLIT_PMD for uprobe register
Attaching uprobe to text section in THP splits the PMD mapped page table
into PTE mapped entries.  On uprobe detach, we would like to regroup PMD
mapped page table entry to regain performance benefit of THP.

However, the regroup is broken For perf_event based trace_uprobe.  This
is because perf_event based trace_uprobe calls uprobe_unregister twice
on close: first in TRACE_REG_PERF_CLOSE, then in
TRACE_REG_PERF_UNREGISTER.  The second call will split the PMD mapped
page table entry, which is not the desired behavior.

Fix this by only use FOLL_SPLIT_PMD for uprobe register case.

Add a WARN() to confirm uprobe unregister never work on huge pages, and
abort the operation when this WARN() triggers.

Link: http://lkml.kernel.org/r/20191017164223.2762148-6-songliubraving@fb.com
Fixes: 5a52c9df62 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT")
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-19 06:32:33 -04:00
Zhengjun Xing
9fa8c9c647 tracing: Fix "gfp_t" format for synthetic events
In the format of synthetic events, the "gfp_t" is shown as "signed:1",
but in fact the "gfp_t" is "unsigned", should be shown as "signed:0".

The issue can be reproduced by the following commands:

echo 'memlatency u64 lat; unsigned int order; gfp_t gfp_flags; int migratetype' > /sys/kernel/debug/tracing/synthetic_events
cat  /sys/kernel/debug/tracing/events/synthetic/memlatency/format

name: memlatency
ID: 2233
format:
        field:unsigned short common_type;       offset:0;       size:2; signed:0;
        field:unsigned char common_flags;       offset:2;       size:1; signed:0;
        field:unsigned char common_preempt_count;       offset:3;       size:1; signed:0;
        field:int common_pid;   offset:4;       size:4; signed:1;

        field:u64 lat;  offset:8;       size:8; signed:0;
        field:unsigned int order;       offset:16;      size:4; signed:0;
        field:gfp_t gfp_flags;  offset:24;      size:4; signed:1;
        field:int migratetype;  offset:32;      size:4; signed:1;

print fmt: "lat=%llu, order=%u, gfp_flags=%x, migratetype=%d", REC->lat, REC->order, REC->gfp_flags, REC->migratetype

Link: http://lkml.kernel.org/r/20191018012034.6404-1-zhengjun.xing@linux.intel.com

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Zhengjun Xing <zhengjun.xing@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-18 14:42:53 -04:00
Linus Torvalds
e59b76ff67 Power management fixes for 5.4-rc4
- Fix possible NULL pointer dereference in the ACPI processor
    scaling initialization code introduced by a recent cpufreq
    update (Rafael Wysocki).
 
  - Fix possible deadlock due to suspending cpufreq too late during
    system shutdown (Rafael Wysocki).
 
  - Make the PCI device system resume code path be more consistent
    with its PM-runtime counterpart to fix an issue with missing
    delay on transitions from D3cold to D0 during system resume from
    suspend-to-idle on some systems (Rafael Wysocki).
 
  - Drop Dell XPS13 9360 from the LPS0 Idle _DSM blacklist to make it
    use suspend-to-idle by default (Mario Limonciello).
 
  - Fix build warning in the core system suspend support code (Ben
    Dooks).
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAl2pgDcSHHJqd0Byand5
 c29ja2kubmV0AAoJEILEb/54YlRxsCQQAJ6L+CC5kEmjfkFeUvCR7xe37wEdeCYc
 NL13rDuKAKQDK6ayJtHp6LUPpSiotOzvjohFplLyn8dAZ7x8V0/KOOGeoL35GSlN
 u18AxkRXT79AzrW1SoDm2TnCCZYV0aW5RupGzPd4vso+E5Q5S3e9Ugk3PBxQfTYH
 YKOr7SpBBICma8ZgplR4tUTLb8brhR/NUAIOVyze52gUKh366kZbDD5tn8eHUxXq
 CBj4ryyV88aeQH2sM1sfvdIlDgFgHrO5GOzcDCCKrEtddqP/hSZyHU+OCH35Vu1v
 it96AEx58IEmd8I18tNZtu5rm1b89YkHeuoh/UF92zCYvk4RVg+Dw3AF0NZVjMQo
 vO7xyO93H48TClHcCwxIOhdI16bXidYfVR1JTeTINvaR7mNZtUddSCEFVKwCazbP
 FC55pVPeUx+HbC6TBQJ9gOSxO2yc2f+uLUXfnKgOpeFZpQuX/WhzuWqUlXgBF2QK
 FHOdfVvX1p1tE9U+3sMLyx1Sln+gqtd2P6GnGzewqIAl43LyJBC4l1s+nkE1b5fc
 7pa0rEqLu4NtGj5O+YQvp+luTQ9FcVL9K5tTuqV4V1Kt+/bzjfIvaEJpwHs44yrZ
 tP2/YCCiA84Hy8SqS4Txk+D14XVYuRguTMBzcmWj2POKFTbDsIhC9bAEZgfJZJNK
 /S2jf5CTnZtl
 =67IL
 -----END PGP SIGNATURE-----

Merge tag 'pm-5.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These include a fix for a recent regression in the ACPI CPU
performance scaling code, a PCI device power management fix,
a system shutdown fix related to cpufreq, a removal of an ACPI
suspend-to-idle blacklist entry and a build warning fix.

Specifics:

   - Fix possible NULL pointer dereference in the ACPI processor scaling
     initialization code introduced by a recent cpufreq update (Rafael
     Wysocki).

   - Fix possible deadlock due to suspending cpufreq too late during
     system shutdown (Rafael Wysocki).

   - Make the PCI device system resume code path be more consistent with
     its PM-runtime counterpart to fix an issue with missing delay on
     transitions from D3cold to D0 during system resume from
     suspend-to-idle on some systems (Rafael Wysocki).

   - Drop Dell XPS13 9360 from the LPS0 Idle _DSM blacklist to make it
     use suspend-to-idle by default (Mario Limonciello).

   - Fix build warning in the core system suspend support code (Ben
     Dooks)"

* tag 'pm-5.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: processor: Avoid NULL pointer dereferences at init time
  PCI: PM: Fix pci_power_up()
  PM: sleep: include <linux/pm_runtime.h> for pm_wq
  cpufreq: Avoid cpufreq_suspend() deadlock on system shutdown
  ACPI: PM: Drop Dell XPS13 9360 from LPS0 Idle _DSM blacklist
2019-10-18 08:34:04 -07:00
Rafael J. Wysocki
b23eb5c74e Merge branches 'pm-cpufreq' and 'pm-sleep'
* pm-cpufreq:
  ACPI: processor: Avoid NULL pointer dereferences at init time
  cpufreq: Avoid cpufreq_suspend() deadlock on system shutdown

* pm-sleep:
  PM: sleep: include <linux/pm_runtime.h> for pm_wq
  ACPI: PM: Drop Dell XPS13 9360 from LPS0 Idle _DSM blacklist
2019-10-18 10:27:55 +02:00
Yunfeng Ye
d7e78706e4 perf/ring_buffer: Matching the memory allocate and free, in rb_alloc()
Currently perf_mmap_alloc_page() is used to allocate memory in
rb_alloc(), but using free_page() to free memory in the failure path.

It's better to use perf_mmap_free_page() instead.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <jolsa@redhat.co>
Cc: <acme@kernel.org>
Cc: <mingo@redhat.com>
Cc: <mark.rutland@arm.com>
Cc: <namhyung@kernel.org>
Cc: <alexander.shishkin@linux.intel.com>
Link: https://lkml.kernel.org/r/575c7e8c-90c7-4e3a-b41d-f894d8cdbd7f@huawei.com
2019-10-17 21:31:55 +02:00
Yunfeng Ye
8a9f91c51e perf/ring_buffer: Modify the parameter type of perf_mmap_free_page()
In perf_mmap_free_page(), the unsigned long type is converted to the
pointer type, but where the call is made, the pointer type is converted
to the unsigned long type. There is no need to do these operations.

Modify the parameter type of perf_mmap_free_page() to pointer type.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <jolsa@redhat.co>
Cc: <acme@kernel.org>
Cc: <mingo@redhat.com>
Cc: <mark.rutland@arm.com>
Cc: <namhyung@kernel.org>
Cc: <alexander.shishkin@linux.intel.com>
Link: https://lkml.kernel.org/r/e6ae3f0c-d04c-50f9-544a-aee3b30330cd@huawei.com
2019-10-17 21:31:55 +02:00
Joel Fernandes (Google)
da97e18458 perf_event: Add support for LSM and SELinux checks
In current mainline, the degree of access to perf_event_open(2) system
call depends on the perf_event_paranoid sysctl.  This has a number of
limitations:

1. The sysctl is only a single value. Many types of accesses are controlled
   based on the single value thus making the control very limited and
   coarse grained.
2. The sysctl is global, so if the sysctl is changed, then that means
   all processes get access to perf_event_open(2) opening the door to
   security issues.

This patch adds LSM and SELinux access checking which will be used in
Android to access perf_event_open(2) for the purposes of attaching BPF
programs to tracepoints, perf profiling and other operations from
userspace. These operations are intended for production systems.

5 new LSM hooks are added:
1. perf_event_open: This controls access during the perf_event_open(2)
   syscall itself. The hook is called from all the places that the
   perf_event_paranoid sysctl is checked to keep it consistent with the
   systctl. The hook gets passed a 'type' argument which controls CPU,
   kernel and tracepoint accesses (in this context, CPU, kernel and
   tracepoint have the same semantics as the perf_event_paranoid sysctl).
   Additionally, I added an 'open' type which is similar to
   perf_event_paranoid sysctl == 3 patch carried in Android and several other
   distros but was rejected in mainline [1] in 2016.

2. perf_event_alloc: This allocates a new security object for the event
   which stores the current SID within the event. It will be useful when
   the perf event's FD is passed through IPC to another process which may
   try to read the FD. Appropriate security checks will limit access.

3. perf_event_free: Called when the event is closed.

4. perf_event_read: Called from the read(2) and mmap(2) syscalls for the event.

5. perf_event_write: Called from the ioctl(2) syscalls for the event.

[1] https://lwn.net/Articles/696240/

Since Peter had suggest LSM hooks in 2016 [1], I am adding his
Suggested-by tag below.

To use this patch, we set the perf_event_paranoid sysctl to -1 and then
apply selinux checking as appropriate (default deny everything, and then
add policy rules to give access to domains that need it). In the future
we can remove the perf_event_paranoid sysctl altogether.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Co-developed-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: James Morris <jmorris@namei.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: rostedt@goodmis.org
Cc: Yonghong Song <yhs@fb.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: jeffv@google.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: primiano@google.com
Cc: Song Liu <songliubraving@fb.com>
Cc: rsavitski@google.com
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Matthew Garrett <matthewgarrett@google.com>
Link: https://lkml.kernel.org/r/20191014170308.70668-1-joel@joelfernandes.org
2019-10-17 21:31:55 +02:00
Mark Rutland
b1fc583335 stop_machine: Avoid potential race behaviour
Both multi_cpu_stop() and set_state() access multi_stop_data::state
racily using plain accesses. These are subject to compiler
transformations which could break the intended behaviour of the code,
and this situation is detected by KCSAN on both arm64 and x86 (splats
below).

Improve matters by using READ_ONCE() and WRITE_ONCE() to ensure that the
compiler cannot elide, replay, or tear loads and stores.

In multi_cpu_stop() the two loads of multi_stop_data::state are expected to
be a consistent value, so snapshot the value into a temporary variable to
ensure this.

The state transitions are serialized by atomic manipulation of
multi_stop_data::num_threads, and other fields in multi_stop_data are not
modified while subject to concurrent reads.

KCSAN splat on arm64:

| BUG: KCSAN: data-race in multi_cpu_stop+0xa8/0x198 and set_state+0x80/0xb0
|
| write to 0xffff00001003bd00 of 4 bytes by task 24 on cpu 3:
|  set_state+0x80/0xb0
|  multi_cpu_stop+0x16c/0x198
|  cpu_stopper_thread+0x170/0x298
|  smpboot_thread_fn+0x40c/0x560
|  kthread+0x1a8/0x1b0
|  ret_from_fork+0x10/0x18
|
| read to 0xffff00001003bd00 of 4 bytes by task 14 on cpu 1:
|  multi_cpu_stop+0xa8/0x198
|  cpu_stopper_thread+0x170/0x298
|  smpboot_thread_fn+0x40c/0x560
|  kthread+0x1a8/0x1b0
|  ret_from_fork+0x10/0x18
|
| Reported by Kernel Concurrency Sanitizer on:
| CPU: 1 PID: 14 Comm: migration/1 Not tainted 5.3.0-00007-g67ab35a199f4-dirty #3
| Hardware name: linux,dummy-virt (DT)

KCSAN splat on x86:

| write to 0xffffb0bac0013e18 of 4 bytes by task 19 on cpu 2:
|  set_state kernel/stop_machine.c:170 [inline]
|  ack_state kernel/stop_machine.c:177 [inline]
|  multi_cpu_stop+0x1a4/0x220 kernel/stop_machine.c:227
|  cpu_stopper_thread+0x19e/0x280 kernel/stop_machine.c:516
|  smpboot_thread_fn+0x1a8/0x300 kernel/smpboot.c:165
|  kthread+0x1b5/0x200 kernel/kthread.c:255
|  ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:352
|
| read to 0xffffb0bac0013e18 of 4 bytes by task 44 on cpu 7:
|  multi_cpu_stop+0xb4/0x220 kernel/stop_machine.c:213
|  cpu_stopper_thread+0x19e/0x280 kernel/stop_machine.c:516
|  smpboot_thread_fn+0x1a8/0x300 kernel/smpboot.c:165
|  kthread+0x1b5/0x200 kernel/kthread.c:255
|  ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:352
|
| Reported by Kernel Concurrency Sanitizer on:
| CPU: 7 PID: 44 Comm: migration/7 Not tainted 5.3.0+ #1
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20191007104536.27276-1-mark.rutland@arm.com
2019-10-17 12:47:12 +02:00
Dmitry Goldin
700dea5a0b kheaders: substituting --sort in archive creation
The option --sort=ORDER was only introduced in tar 1.28 (2014), which
is rather new and might not be available in some setups.

This patch tries to replicate the previous behaviour as closely as
possible to fix the kheaders build for older environments. It does
not produce identical archives compared to the previous version due
to minor sorting differences but produces reproducible results itself
in my tests.

Reported-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Dmitry Goldin <dgoldin+lkml@protonmail.ch>
Tested-by: Andreas Schwab <schwab@suse.de>
Tested-by: Quentin Perret <qperret@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-10-17 09:08:19 +09:00
Ben Dooks
bc88f85c6c kthread: make __kthread_queue_delayed_work static
The __kthread_queue_delayed_work is not exported so
make it static, to avoid the following sparse warning:

  kernel/kthread.c:869:6: warning: symbol '__kthread_queue_delayed_work' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-16 09:20:58 -07:00
Linus Torvalds
02755af0f3 Merge branch 'parisc-5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc fixes from Helge Deller:

 - Fix a parisc-specific fallout of Christoph's
   dma_set_mask_and_coherent() patches (Sven)

 - Fix a vmap memory leak in ioremap()/ioremap() (Helge)

 - Some minor cleanups and documentation updates (Nick, Helge)

* 'parisc-5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Remove 32-bit DMA enforcement from sba_iommu
  parisc: Fix vmap memory leak in ioremap()/iounmap()
  parisc: prefer __section from compiler_attributes.h
  parisc: sysctl.c: Use CONFIG_PARISC instead of __hppa_ define
  MAINTAINERS: Add hp_sdc drivers to parisc arch
2019-10-15 09:37:01 -07:00
Helge Deller
b67114db64 parisc: sysctl.c: Use CONFIG_PARISC instead of __hppa_ define
Signed-off-by: Helge Deller <deller@gmx.de>
2019-10-14 21:43:54 +02:00
Eric Dumazet
ff229eee3d hrtimer: Annotate lockless access to timer->base
Followup to commit dd2261ed45 ("hrtimer: Protect lockless access
to timer->base")

lock_hrtimer_base() fetches timer->base without lock exclusion.

Compiler is allowed to read timer->base twice (even if considered dumb)
which could end up trying to lock migration_base and return
&migration_base.

  base = timer->base;
  if (likely(base != &migration_base)) {

       /* compiler reads timer->base again, and now (base == &migration_base)

       raw_spin_lock_irqsave(&base->cpu_base->lock, *flags);
       if (likely(base == timer->base))
            return base; /* == &migration_base ! */

Similarly the write sides must use WRITE_ONCE() to avoid store tearing.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191008173204.180879-1-edumazet@google.com
2019-10-14 15:51:49 +02:00
Linus Torvalds
d4615e5a46 A few tracing fixes:
- Removed locked down from tracefs itself and moved it to the trace
    directory. Having the open functions there do the lockdown checks.
 
  - Fixed a few races with opening an instance file and the instance being
    deleted (Discovered during the locked down updates). Kept separate
    from the clean up code such that they can be backported to stable
    easier.
 
  - Cleaned up and consolidated the checks done when opening a trace
    file, as there were multiple checks that need to be done, and it
    did not make sense having them done in each open instance.
 
  - Fixed a regression in the record mcount code.
 
  - Small hw_lat detector tracer fixes.
 
  - A trace_pipe read fix due to not initializing trace_seq.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCXaNhphQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6quDIAP4v08ARNdIh+r+c4AOBm3xsOuE/d9GB
 I56ydnskm+x2JQD6Ap9ivXe9yDBIErFeHNtCoq7pM8YDI4YoYIB30N0GfwM=
 =7oAu
 -----END PGP SIGNATURE-----

Merge tag 'trace-v5.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "A few tracing fixes:

   - Remove lockdown from tracefs itself and moved it to the trace
     directory. Have the open functions there do the lockdown checks.

   - Fix a few races with opening an instance file and the instance
     being deleted (Discovered during the lockdown updates). Kept
     separate from the clean up code such that they can be backported to
     stable easier.

   - Clean up and consolidated the checks done when opening a trace
     file, as there were multiple checks that need to be done, and it
     did not make sense having them done in each open instance.

   - Fix a regression in the record mcount code.

   - Small hw_lat detector tracer fixes.

   - A trace_pipe read fix due to not initializing trace_seq"

* tag 'trace-v5.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Initialize iter->seq after zeroing in tracing_read_pipe()
  tracing/hwlat: Don't ignore outer-loop duration when calculating max_latency
  tracing/hwlat: Report total time spent in all NMIs during the sample
  recordmcount: Fix nop_mcount() function
  tracing: Do not create tracefs files if tracefs lockdown is in effect
  tracing: Add locked_down checks to the open calls of files created for tracefs
  tracing: Add tracing_check_open_get_tr()
  tracing: Have trace events system open call tracing_open_generic_tr()
  tracing: Get trace_array reference for available_tracers files
  ftrace: Get a reference counter for the trace_array on filter files
  tracefs: Revert ccbd54ff54 ("tracefs: Restrict tracefs when the kernel is locked down")
2019-10-13 14:47:10 -07:00
Petr Mladek
d303de1fcf tracing: Initialize iter->seq after zeroing in tracing_read_pipe()
A customer reported the following softlockup:

[899688.160002] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [test.sh:16464]
[899688.160002] CPU: 0 PID: 16464 Comm: test.sh Not tainted 4.12.14-6.23-azure #1 SLE12-SP4
[899688.160002] RIP: 0010:up_write+0x1a/0x30
[899688.160002] Kernel panic - not syncing: softlockup: hung tasks
[899688.160002] RIP: 0010:up_write+0x1a/0x30
[899688.160002] RSP: 0018:ffffa86784d4fde8 EFLAGS: 00000257 ORIG_RAX: ffffffffffffff12
[899688.160002] RAX: ffffffff970fea00 RBX: 0000000000000001 RCX: 0000000000000000
[899688.160002] RDX: ffffffff00000001 RSI: 0000000000000080 RDI: ffffffff970fea00
[899688.160002] RBP: ffffffffffffffff R08: ffffffffffffffff R09: 0000000000000000
[899688.160002] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8b59014720d8
[899688.160002] R13: ffff8b59014720c0 R14: ffff8b5901471090 R15: ffff8b5901470000
[899688.160002]  tracing_read_pipe+0x336/0x3c0
[899688.160002]  __vfs_read+0x26/0x140
[899688.160002]  vfs_read+0x87/0x130
[899688.160002]  SyS_read+0x42/0x90
[899688.160002]  do_syscall_64+0x74/0x160

It caught the process in the middle of trace_access_unlock(). There is
no loop. So, it must be looping in the caller tracing_read_pipe()
via the "waitagain" label.

Crashdump analyze uncovered that iter->seq was completely zeroed
at this point, including iter->seq.seq.size. It means that
print_trace_line() was never able to print anything and
there was no forward progress.

The culprit seems to be in the code:

	/* reset all but tr, trace, and overruns */
	memset(&iter->seq, 0,
	       sizeof(struct trace_iterator) -
	       offsetof(struct trace_iterator, seq));

It was added by the commit 53d0aa7730 ("ftrace:
add logic to record overruns"). It was v2.6.27-rc1.
It was the time when iter->seq looked like:

     struct trace_seq {
	unsigned char		buffer[PAGE_SIZE];
	unsigned int		len;
     };

There was no "size" variable and zeroing was perfectly fine.

The solution is to reinitialize the structure after or without
zeroing.

Link: http://lkml.kernel.org/r/20191011142134.11997-1-pmladek@suse.com

Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-12 20:49:34 -04:00
Srivatsa S. Bhat (VMware)
fc64e4ad80 tracing/hwlat: Don't ignore outer-loop duration when calculating max_latency
max_latency is intended to record the maximum ever observed hardware
latency, which may occur in either part of the loop (inner/outer). So
we need to also consider the outer-loop sample when updating
max_latency.

Link: http://lkml.kernel.org/r/157073345463.17189.18124025522664682811.stgit@srivatsa-ubuntu

Fixes: e7c15cd8a1 ("tracing: Added hardware latency tracer")
Cc: stable@vger.kernel.org
Signed-off-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-12 20:49:33 -04:00
Srivatsa S. Bhat (VMware)
98dc19c114 tracing/hwlat: Report total time spent in all NMIs during the sample
nmi_total_ts is supposed to record the total time spent in *all* NMIs
that occur on the given CPU during the (active portion of the)
sampling window. However, the code seems to be overwriting this
variable for each NMI, thereby only recording the time spent in the
most recent NMI. Fix it by accumulating the duration instead.

Link: http://lkml.kernel.org/r/157073343544.17189.13911783866738671133.stgit@srivatsa-ubuntu

Fixes: 7b2c862501 ("tracing: Add NMI tracing in hwlat detector")
Cc: stable@vger.kernel.org
Signed-off-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-12 20:49:33 -04:00
Steven Rostedt (VMware)
17911ff38a tracing: Add locked_down checks to the open calls of files created for tracefs
Added various checks on open tracefs calls to see if tracefs is in lockdown
mode, and if so, to return -EPERM.

Note, the event format files (which are basically standard on all machines)
as well as the enabled_functions file (which shows what is currently being
traced) are not lockde down. Perhaps they should be, but it seems counter
intuitive to lockdown information to help you know if the system has been
modified.

Link: http://lkml.kernel.org/r/CAHk-=wj7fGPKUspr579Cii-w_y60PtRaiDgKuxVtBAMK0VNNkA@mail.gmail.com

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-12 20:48:06 -04:00
Steven Rostedt (VMware)
8530dec63e tracing: Add tracing_check_open_get_tr()
Currently, most files in the tracefs directory test if tracing_disabled is
set. If so, it should return -ENODEV. The tracing_disabled is called when
tracing is found to be broken. Originally it was done in case the ring
buffer was found to be corrupted, and we wanted to prevent reading it from
crashing the kernel. But it's also called if a tracing selftest fails on
boot. It's a one way switch. That is, once it is triggered, tracing is
disabled until reboot.

As most tracefs files can also be used by instances in the tracefs
directory, they need to be carefully done. Each instance has a trace_array
associated to it, and when the instance is removed, the trace_array is
freed. But if an instance is opened with a reference to the trace_array,
then it requires looking up the trace_array to get its ref counter (as there
could be a race with it being deleted and the open itself). Once it is
found, a reference is added to prevent the instance from being removed (and
the trace_array associated with it freed).

Combine the two checks (tracing_disabled and trace_array_get()) into a
single helper function. This will also make it easier to add lockdown to
tracefs later.

Link: http://lkml.kernel.org/r/20191011135458.7399da44@gandalf.local.home

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-12 20:44:07 -04:00
Steven Rostedt (VMware)
aa07d71f1b tracing: Have trace events system open call tracing_open_generic_tr()
Instead of having the trace events system open call open code the taking of
the trace_array descriptor (with trace_array_get()) and then calling
trace_open_generic(), have it use the tracing_open_generic_tr() that does
the combination of the two. This requires making tracing_open_generic_tr()
global.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-12 20:43:00 -04:00
Steven Rostedt (VMware)
194c2c74f5 tracing: Get trace_array reference for available_tracers files
As instances may have different tracers available, we need to look at the
trace_array descriptor that shows the list of the available tracers for the
instance. But there's a race between opening the file and an admin
deleting the instance. The trace_array_get() needs to be called before
accessing the trace_array.

Cc: stable@vger.kernel.org
Fixes: 607e2ea167 ("tracing: Set up infrastructure to allow tracers for instances")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-12 20:40:50 -04:00
Steven Rostedt (VMware)
9ef16693af ftrace: Get a reference counter for the trace_array on filter files
The ftrace set_ftrace_filter and set_ftrace_notrace files are specific for
an instance now. They need to take a reference to the instance otherwise
there could be a race between accessing the files and deleting the instance.

It wasn't until the :mod: caching where these file operations started
referencing the trace_array directly.

Cc: stable@vger.kernel.org
Fixes: 673feb9d76 ("ftrace: Add :mod: caching infrastructure to trace_array")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-12 20:40:21 -04:00
Linus Torvalds
328fefadd9 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Two fixes: a guest-cputime accounting fix, and a cgroup bandwidth
  quota precision fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/vtime: Fix guest/system mis-accounting on task switch
  sched/fair: Scale bandwidth quota and period without losing quota/period ratio precision
2019-10-12 15:29:54 -07:00
Linus Torvalds
465a7e291f Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Mostly tooling fixes, but also a couple of updates for new Intel
  models (which are technically hw-enablement, but to users it's a fix
  to perf behavior on those new CPUs - hope this is fine), an AUX
  inheritance fix, event time-sharing fix, and a fix for lost non-perf
  NMI events on AMD systems"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  perf/x86/cstate: Add Tiger Lake CPU support
  perf/x86/msr: Add Tiger Lake CPU support
  perf/x86/intel: Add Tiger Lake CPU support
  perf/x86/cstate: Update C-state counters for Ice Lake
  perf/x86/msr: Add new CPU model numbers for Ice Lake
  perf/x86/cstate: Add Comet Lake CPU support
  perf/x86/msr: Add Comet Lake CPU support
  perf/x86/intel: Add Comet Lake CPU support
  perf/x86/amd: Change/fix NMI latency mitigation to use a timestamp
  perf/core: Fix corner case in perf_rotate_context()
  perf/core: Rework memory accounting in perf_mmap()
  perf/core: Fix inheritance of aux_output groups
  perf annotate: Don't return -1 for error when doing BPF disassembly
  perf annotate: Return appropriate error code for allocation failures
  perf annotate: Fix arch specific ->init() failure errors
  perf annotate: Propagate the symbol__annotate() error return
  perf annotate: Fix the signedness of failure returns
  perf annotate: Propagate perf_env__arch() error
  perf evsel: Fall back to global 'perf_env' in perf_evsel__env()
  perf tools: Propagate get_cpuid() error
  ...
2019-10-12 15:15:17 -07:00
Linus Torvalds
297cbcccc2 for-linus-20191010
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAl2f5MIQHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpvscD/4v8E1s1rt6JwqM0Fa27UjRdhfGnc8ad8vs
 fD7rf3ZmLkoM1apVopMcAscUH726wU4qbxwEUDEntxxv2wJHuZdSZ64zhFJ17uis
 uJ2pF4MpK/m6DnHZu/SAU4t9aU+l6SBqX0tS1bFycecPgGRk46jrVX5tNJggt0Fy
 hqmx3ACWbkGiFDERT2AAQ69WHfmzeI9aUjx3jJY2eLnK7OjjEpyoEBs0j/AHl3ep
 kydhItU5NSFCv94X7vmZy/dvQ5hE4/1HTFfg79fOZcywQi1AN5DafKxiM2kgaSJ0
 jW58i+AFVtUPysNpVsxvjAgqGwDX/UJkOkggPd6V8/6LMfEvBKY4YNXlUEbqTN3Y
 pqn19/cgdKHaQpHKqwettcQujc71kry/yHsaudD+g2fi0efYi3d4qxIp9XA0TF03
 z6jzp8Hfo2SKbwapIFPa7Wqj86ZpbBxtROibCA17WKSNzn0UR3pJmEigo4l364ow
 nJpvZChLDHZXjovgzISmUnbR+O1yP0+ZnI9b7kgNp0UV4SI5ajf6f2T7667dcQs0
 J1GNt4QvqPza3R0z1SuoEi6tbc3GyMj7NZyIseNOXR/NtqXEWtiNvDIuZqs6Wn/T
 4GhaF0Mjqc17B3UEkdU1z09HL0JR40vUrGYE4lDxHhPWd0YngDGJJX2pZG2Y0WBp
 VQ20AzijzQ==
 =wZnt
 -----END PGP SIGNATURE-----

Merge tag 'for-linus-20191010' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Fix wbt performance regression introduced with the blk-rq-qos
   refactoring (Harshad)

 - Fix io_uring fileset removal inadvertently killing the workqueue (me)

 - Fix io_uring typo in linked command nonblock submission (Pavel)

 - Remove spurious io_uring wakeups on request free (Pavel)

 - Fix null_blk zoned command error return (Keith)

 - Don't use freezable workqueues for backing_dev, also means we can
   revert a previous libata hack (Mika)

 - Fix nbd sysfs mutex dropped too soon at removal time (Xiubo)

* tag 'for-linus-20191010' of git://git.kernel.dk/linux-block:
  nbd: fix possible sysfs duplicate warning
  null_blk: Fix zoned command return code
  io_uring: only flush workqueues on fileset removal
  io_uring: remove wait loop spurious wakeups
  blk-wbt: fix performance regression in wbt scale_up/scale_down
  Revert "libata, freezer: avoid block device removal while system is frozen"
  bdi: Do not use freezable workqueue
  io_uring: fix reversed nonblock flag for link submission
2019-10-11 08:45:32 -07:00
Ben Dooks
f49249d58a PM: sleep: include <linux/pm_runtime.h> for pm_wq
Include the <linux/runtime_pm.h> for the definition of
pm_wq to avoid the following warning:

kernel/power/main.c:890:25: warning: symbol 'pm_wq' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-10-10 11:11:56 +02:00
Song Liu
7fa343b7fd perf/core: Fix corner case in perf_rotate_context()
In perf_rotate_context(), when the first cpu flexible event fail to
schedule, cpu_rotate is 1, while cpu_event is NULL. Since cpu_event is
NULL, perf_rotate_context will _NOT_ call cpu_ctx_sched_out(), thus
cpuctx->ctx.is_active will have EVENT_FLEXIBLE set. Then, the next
perf_event_sched_in() will skip all cpu flexible events because of the
EVENT_FLEXIBLE bit.

In the next call of perf_rotate_context(), cpu_rotate stays 1, and
cpu_event stays NULL, so this process repeats. The end result is, flexible
events on this cpu will not be scheduled (until another event being added
to the cpuctx).

Here is an easy repro of this issue. On Intel CPUs, where ref-cycles
could only use one counter, run one pinned event for ref-cycles, one
flexible event for ref-cycles, and one flexible event for cycles. The
flexible ref-cycles is never scheduled, which is expected. However,
because of this issue, the cycles event is never scheduled either.

 $ perf stat -e ref-cycles:D,ref-cycles,cycles -C 5 -I 1000

           time             counts unit events
    1.000152973         15,412,480      ref-cycles:D
    1.000152973      <not counted>      ref-cycles     (0.00%)
    1.000152973      <not counted>      cycles         (0.00%)
    2.000486957         18,263,120      ref-cycles:D
    2.000486957      <not counted>      ref-cycles     (0.00%)
    2.000486957      <not counted>      cycles         (0.00%)

To fix this, when the flexible_active list is empty, try rotate the
first event in the flexible_groups. Also, rename ctx_first_active() to
ctx_event_to_rotate(), which is more accurate.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <kernel-team@fb.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 8d5bce0c37 ("perf/core: Optimize perf_rotate_context() event scheduling")
Link: https://lkml.kernel.org/r/20191008165949.920548-1-songliubraving@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-09 12:44:13 +02:00
Song Liu
d44248a413 perf/core: Rework memory accounting in perf_mmap()
perf_mmap() always increases user->locked_vm. As a result, "extra" could
grow bigger than "user_extra", which doesn't make sense. Here is an
example case:

(Note: Assume "user_lock_limit" is very small.)

  | # of perf_mmap calls |vma->vm_mm->pinned_vm|user->locked_vm|
  | 0                    | 0                   | 0             |
  | 1                    | user_extra          | user_extra    |
  | 2                    | 3 * user_extra      | 2 * user_extra|
  | 3                    | 6 * user_extra      | 3 * user_extra|
  | 4                    | 10 * user_extra     | 4 * user_extra|

Fix this by maintaining proper user_extra and extra.

Reviewed-By: Hechao Li <hechaol@fb.com>
Reported-by: Hechao Li <hechaol@fb.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <kernel-team@fb.com>
Cc: Jie Meng <jmeng@fb.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/20190904214618.3795672-1-songliubraving@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-09 12:44:12 +02:00
Frederic Weisbecker
68e7a4d66b sched/vtime: Fix guest/system mis-accounting on task switch
vtime_account_system() assumes that the target task to account cputime
to is always the current task. This is most often true indeed except on
task switch where we call:

	vtime_common_task_switch(prev)
		vtime_account_system(prev)

Here prev is the scheduling-out task where we account the cputime to. It
doesn't match current that is already the scheduling-in task at this
stage of the context switch.

So we end up checking the wrong task flags to determine if we are
accounting guest or system time to the previous task.

As a result the wrong task is used to check if the target is running in
guest mode. We may then spuriously account or leak either system or
guest time on task switch.

Fix this assumption and also turn vtime_guest_enter/exit() to use the
task passed in parameter as well to avoid future similar issues.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <wanpengli@tencent.com>
Fixes: 2a42eb9594 ("sched/cputime: Accumulate vtime on top of nsec clocksource")
Link: https://lkml.kernel.org/r/20190925214242.21873-1-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-09 12:38:03 +02:00
Xuewei Zhang
4929a4e6fa sched/fair: Scale bandwidth quota and period without losing quota/period ratio precision
The quota/period ratio is used to ensure a child task group won't get
more bandwidth than the parent task group, and is calculated as:

  normalized_cfs_quota() = [(quota_us << 20) / period_us]

If the quota/period ratio was changed during this scaling due to
precision loss, it will cause inconsistency between parent and child
task groups.

See below example:

A userspace container manager (kubelet) does three operations:

 1) Create a parent cgroup, set quota to 1,000us and period to 10,000us.
 2) Create a few children cgroups.
 3) Set quota to 1,000us and period to 10,000us on a child cgroup.

These operations are expected to succeed. However, if the scaling of
147/128 happens before step 3, quota and period of the parent cgroup
will be changed:

  new_quota: 1148437ns,   1148us
 new_period: 11484375ns, 11484us

And when step 3 comes in, the ratio of the child cgroup will be
104857, which will be larger than the parent cgroup ratio (104821),
and will fail.

Scaling them by a factor of 2 will fix the problem.

Tested-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Xuewei Zhang <xueweiz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Phil Auld <pauld@redhat.com>
Cc: Anton Blanchard <anton@ozlabs.org>
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: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Fixes: 2e8e192263 ("sched/fair: Limit sched_cfs_period_timer() loop to avoid hard lockup")
Link: https://lkml.kernel.org/r/20191004001243.140897-1-xueweiz@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-09 12:38:02 +02:00