Re: [PATCH 1/1] Fix int1 recursion when no perf_bp_event is registeredy

From: Thomas Gleixner
Date: Thu Dec 10 2015 - 15:51:50 EST


On Thu, 10 Dec 2015, Andy Lutomirski wrote:
> On brief inspection, this smells like a microcode bug. Can you send
> /proc/cpuinfo output?
>
> If this is the issue, I'm not sure we want to be in the business of
> working around localized microcode bugs and, if we do, then I think we
> should explicitly detect the bug and log about it.

I think we should handle such stuff gracefully. Yes, we should log it
and we also should check what the contents of the debug registers are.

If dr7 has a break point enabled w/o perf having one installed then we
know that someone did a horrible hackery ....

Thanks,

tglx


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