[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Thu, 4 Apr 2019 16:33:27 +0300
From: Cyrill Gorcunov <gorcunov@...il.com>
To: Vince Weaver <vincent.weaver@...ne.edu>
Cc: Peter Zijlstra <peterz@...radead.org>,
linux-kernel@...r.kernel.org,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
Namhyung Kim <namhyung@...nel.org>,
Thomas Gleixner <tglx@...utronix.de>,
Jiri Olsa <jolsa@...hat.com>,
Stephane Eranian <eranian@...gle.com>
Subject: Re: perf: perf_fuzzer crashes on Pentium 4 systems
On Thu, Apr 04, 2019 at 09:25:47AM -0400, Vince Weaver wrote:
>
> It looks like there are at least two bugs here, one that's a full
> hardlockup with nothing on serial console. The other is the NULL
> dereference.
>
Seems so. I've spent plenty of time yesterday trying to figure out how
we even reach the case when event = nil but without much luck.
> Just ran with your patch applied and it hit the hard lockup case.
>
> I'll have to see if things are reproducible and I can try to see if I can
> get a reproducible value for what even caused the issue. perf_fuzzer has
> some infrastructure for determining that but it's hit or miss if you can
> get anything useful from it.
At least the sequence of events migh give us some ideas, maybe not indeed.
Thanks a huge, Vince!
> I'll keep running things, but I'm a bit busy at work here the next few
> days so there might be some delay in the results.
Sure, take your time. I think this problem with p4 is not urgent. I'll ping
you if I get some more ideas.
Powered by blists - more mailing lists