Commit-ID: 3c3116b745c08dc76ccbed7223c4edddcfd9a186 Gitweb: http://git.kernel.org/tip/3c3116b745c08dc76ccbed7223c4edddcfd9a186 Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx> AuthorDate: Tue, 10 May 2016 14:16:54 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Thu, 12 May 2016 10:14:30 +0200 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@xxxxxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Stephane Eranian <eranian@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vince Weaver <vincent.weaver@xxxxxxxxx> Cc: kan.liang@xxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: luto@xxxxxxxxxx Cc: ray.huang@xxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/events/msr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/events/msr.c b/arch/x86/events/msr.c index ec863b9..8bef19f 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) -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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