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X-Google-Original-From: Vince Weaver <vince@vincent-weaver-1.umelst.maine.edu>
Date: Thu, 1 May 2014 09:22:48 -0400 (EDT)
From: Vince Weaver <vincent.weaver@maine.edu>
To: Peter Zijlstra <peterz@infradead.org>
cc: Thomas Gleixner <tglx@linutronix.de>,
        Vince Weaver <vincent.weaver@maine.edu>,
        Ingo Molnar <mingo@kernel.org>, linux-kernel@vger.kernel.org,
        Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [perf] more perf_fuzzer memory corruption
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On Thu, 1 May 2014, Peter Zijlstra wrote:

> On Thu, May 01, 2014 at 12:51:33AM +0200, Thomas Gleixner wrote:
> > And that's the issue which puzzles us. Let's look at what we expect:
> > 
> > Now the trace shows a different story:
> > 
> >      perf_fuzzer-4387  [001]  1802.628659: sys_enter:            
> NR 298 (69bb58, 0, ffffffff, 12, 0, 0)
> 
> That's a per-cpu event (.pid = -1, .cpu = 12), they don't get inherited,
> so the only thing keeping it alive is the fd the child got. So
> exit_files() killing this thing makes perfect sense.

wait, are you sure?  Isn't that pid=0, cpu=-1, group_fd=12?

my machine only has 8 cpus...

Vince