Re: perf: perf_fuzzer triggers GPF in perf_prepare_sample

[Vince Weaver]

On Wed, 5 Dec 2018, Jiri Olsa wrote:

> On Wed, Dec 05, 2018 at 01:45:38PM +0100, Jiri Olsa wrote:
> > On Tue, Dec 04, 2018 at 10:54:55AM -0500, Vince Weaver wrote:
> > > Hello,
> > > 
> > > I was able to trigger another oops with the perf_fuzzer with current git.
> > > 
> > > This is 4.20-rc5 after the fix for the very similar oops I previously 
> > > reported got committed.
> > > 
> > > It seems to be pointing to the same location in the source as 
> > > before, I guess maybe triggered a different way?
> > 
> > nice.. yep, looks the same
> > 
> > > 
> > > Unfortunately this crash is not easily reproducible like the last one was.
> > 
> > will check
> 
> what model are hitting this on?

Haswell.  6/60/3.

While I can't deterministically trigger this, the fuzzer usually hits it
within an hour or two.  Is there any debug or printk messages I can
add that would help figure out what's going on?

Vince