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Date: Tue, 6 Sep 2016 17:06:40 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
        Ingo Molnar <mingo@redhat.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>, "H. Peter Anvin" <hpa@zytor.com>,
        "x86@kernel.org" <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: perf: out-of-bounds write in perf_callchain_store
Message-ID: <20160906150640.GH2794@worktop>
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On Tue, Sep 06, 2016 at 04:49:29PM +0200, Dmitry Vyukov wrote:
> On Tue, Sep 6, 2016 at 4:44 PM, Arnaldo Carvalho de Melo
> > I looked at it briefly some moments ago, couldn't find it so far, have
> > to look at what was behind adding a sysctl for that :-\
> >
> > And yeah, that entry/ctx thing, IIRC, was done to reduce patch size,
> > probably needs some polishing to become clearer.
> 
> 
> I believe fuzzer wasn't messing with sysctl's.
> But, yeah, I guess it's really bad idea to try to change them on a
> running system.

The sysctl's should return -EBUSY if its in use...