diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2016-05-10 14:16:54 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-05-12 10:14:30 +0200 |
| commit | 3c3116b745c08dc76ccbed7223c4edddcfd9a186 (patch) | |
| tree | f45c7a531d0ec4a2436787816479f176f6341ca7 /arch/x86 | |
| parent | ec336c879c3b422d2876085be1cbb110e44dc0de (diff) | |
perf/x86/msr: Fix SMI overflow
We compute 'delta' and properly sign extend it and then ignore it and
recompute the raw value, loosing the sign extention.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
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>
Cc: kan.liang@intel.com
Cc: linux-kernel@vger.kernel.org
Cc: luto@kernel.org
Cc: ray.huang@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/events/msr.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/events/msr.c b/arch/x86/events/msr.c index ec863b9a9f78..8bef19f098d4 100644 --- a/arch/x86/events/msr.c +++ b/arch/x86/events/msr.c @@ -166,7 +166,7 @@ again: if (unlikely(event->hw.event_base == MSR_SMI_COUNT)) delta = sign_extend64(delta, 31); - local64_add(now - prev, &event->count); + local64_add(delta, &event->count); } static void msr_event_start(struct perf_event *event, int flags) |