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linux/arch/x86/events/intel
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Kan Liang e4557c1a46 perf/x86/intel: Fix spurious NMI on fixed counter 
If a user first sample a PEBS event on a fixed counter, then sample a
non-PEBS event on the same fixed counter on Icelake, it will trigger
spurious NMI. For example:

  perf record -e 'cycles:p' -a
  perf record -e 'cycles' -a

The error message for spurious NMI:

  [June 21 15:38] Uhhuh. NMI received for unknown reason 30 on CPU 2.
  [    +0.000000] Do you have a strange power saving mode enabled?
  [    +0.000000] Dazed and confused, but trying to continue

The bug was introduced by the following commit:

  commit 6f55967ad9 ("perf/x86/intel: Fix race in intel_pmu_disable_event()")

The commit moves the intel_pmu_pebs_disable() after intel_pmu_disable_fixed(),
which returns immediately.  The related bit of PEBS_ENABLE MSR will never be
cleared for the fixed counter. Then a non-PEBS event runs on the fixed counter,
but the bit on PEBS_ENABLE is still set, which triggers spurious NMIs.

Check and disable PEBS for fixed counters after intel_pmu_disable_fixed().

Reported-by: Yi, Ammy <ammy.yi@intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: <stable@vger.kernel.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: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 6f55967ad9 ("perf/x86/intel: Fix race in intel_pmu_disable_event()")
Link: https://lkml.kernel.org/r/20190625142135.22112-1-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-07-13 11:21:29 +02:00
..
bts.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 2019-06-05 17:36:37 +02:00
core.c perf/x86/intel: Fix spurious NMI on fixed counter 2019-07-13 11:21:29 +02:00
cstate.c perf/x86/cstate: Use new probe function 2019-06-24 19:28:33 +02:00
ds.c Merge branch 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 17:34:44 -07:00
knc.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
lbr.c perf/x86/lbr: Avoid reading the LBRs when adaptive PEBS handles them 2019-04-16 12:26:17 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
p4.c x86: Fix various typos in comments 2018-12-03 10:49:13 +01:00
p6.c x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping 2018-02-15 01:15:52 +01:00
pt.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 2019-06-05 17:36:37 +02:00
pt.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288 2019-06-05 17:36:37 +02:00
rapl.c Merge branch 'x86-topology-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 18:28:44 -07:00
uncore_nhmex.c perf/x86/intel/uncore: Correct fixed counter index check for NHM 2018-05-31 12:36:28 +02:00
uncore_snb.c perf/x86/intel/uncore: Clean up client IMC 2019-06-17 12:36:21 +02:00
uncore_snbep.c perf/x86/intel/uncore: Add IMC uncore support for Snow Ridge 2019-06-17 12:36:22 +02:00
uncore.c Merge branch 'x86-topology-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 18:28:44 -07:00
uncore.h perf/x86/intel/uncore: Add IMC uncore support for Snow Ridge 2019-06-17 12:36:22 +02:00