Re: [PATCH 2/2] perf, x86: Don't allow unusual PEBS raw flags

[Peter Zijlstra]

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.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/