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| author |   Stephane Eranian <eranian@google.com> | 2015-12-03 23:33:18 +0100 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2016-01-06 11:15:34 +0100 |
| commit | 1424a09a9e1839285e948d4ea9fdfca26c9a2086 (patch) | |
| tree | 6802e3edfd1e24e3b910c7dcc76be4c3a115811a | |
| parent | perf/x86: Fix LBR related crashes on Intel Atom (diff) | |
| download | linux-dev-1424a09a9e1839285e948d4ea9fdfca26c9a2086.tar.xz linux-dev-1424a09a9e1839285e948d4ea9fdfca26c9a2086.zip | |
perf/x86: fix PEBS issues on Intel Atom/Core2
This patch fixes broken PEBS support on Intel Atom and Core2
due to wrong pointer arithmetic in intel_pmu_drain_pebs_core().
The get_next_pebs_record_by_bit() was called on PEBS format fmt0
which does not use the pebs_record_nhm layout.
Signed-off-by: Stephane Eranian <eranian@google.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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: kan.liang@intel.com
Fixes: 21509084f999 ("perf/x86/intel: Handle multiple records in the PEBS buffer")
Link: http://lkml.kernel.org/r/1449182000-31524-3-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel_ds.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c index 9c0f8d464bc0..a7463ed0b40e 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -1106,6 +1106,13 @@ get_next_pebs_record_by_bit(void *base, void *top, int bit) void *at; u64 pebs_status; + /* + * fmt0 does not have a status bitfield (does not use + * perf_record_nhm format) + */ + if (x86_pmu.intel_cap.pebs_format < 1) + return base; + if (base == NULL) return NULL; @@ -1191,7 +1198,7 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs) if (!event->attr.precise_ip) return; - n = (top - at) / x86_pmu.pebs_record_size; + n = top - at; if (n <= 0) return; |