Re: [PATCH 0/3] perf, bts: Fallout from the fuzzer for perf/urgent

[Vince Weaver]

On Tue, 23 Aug 2016, Alexander Shishkin wrote:

> Recently Vince has reported warnings and panics coming from the
> general direction of AUX tracing. I found two bugs which manifest
> similarly, one in intel_bts driver and one in AUX unmapping path.
> 
> Both are triggered by racing SET_OUTPUT against mmap_close while
> running AUX tracing. I have a test case that set fire to the kernel
> within a few seconds by doing this, which I can share if anyone
> cares.

I've applied these and am fuzzing on my Haswell machine and I'm getting 
lots and lots of

[  945.536374] Dazed and confused, but trying to continue
[  945.542391] Uhhuh. NMI received for unknown reason 21 on CPU 2.
[  945.549360] Do you have a strange power saving mode enabled?
[  945.556701] Dazed and confused, but trying to continue
[  945.563643] Uhhuh. NMI received for unknown reason 31 on CPU 2.
[  945.571379] Do you have a strange power saving mode enabled?
[  945.578754] Dazed and confused, but trying to continue
[  945.630889] Uhhuh. NMI received for unknown reason 31 on CPU 2.
[  945.638141] Do you have a strange power saving mode enabled?
[  945.645523] Dazed and confused, but trying to continue

messages that I wasn't getting before.  Of course, I updated from -rc2 to 
-rc3 before applying the patch so it could also be related to that too, I 
can try backing out the patches and see if it still happens.

Vince