Messages in this thread | | | Date | Tue, 7 May 2013 10:48:03 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 2/2] perf, x86: Don't allow unusual PEBS raw flags |
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On Tue, May 07, 2013 at 08:48:05AM +0200, Ingo Molnar wrote: > Also, this code only runs when the event is set up, so a bit of sanity > checking can only help, right?
Nah, its all very circumspect. In fact; while what Andi states is 'true':
> documentation in the Intel SDM 18.6.1.1 states: > > """ > PEBS events are only valid when the following fields of IA32_PERFEVTSELx are all > zero: AnyThread, Edge, Invert, CMask. > """
It is also true that Intel themselves gave us events that contradict this; look at the intel_pebs_aliases*() functions.
This patch would make it impossible to manually create those events.
Further, there's something entirely different behind this.
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