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Date: Wed, 26 Jan 2011 17:23:12 +0100
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>, linux-kernel <linux-kernel@vger.kernel.org>,
        stable@kernel.org, Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Arnaldo Carvalho de Melo <acme@redhat.com>,
        David Miller <davem@davemloft.net>,
        Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH] perf: fix alloc_callchain_buffers()
Message-ID: <20110126162309.GB1757@nowhere>
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On Tue, Jan 25, 2011 at 07:40:51PM +0100, Eric Dumazet wrote:
> Commit 927c7a9e92c4 ( perf: Fix race in callchains ) introduced a
> mismatch in the sizing of struct callchain_cpus_entries.
> 
> nr_cpu_ids must be used instead of num_possible_cpus(), or we might get
> out of bound memory accesses on some machines.
> 
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> CC: Frederic Weisbecker <fweisbec@gmail.com>
> CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
> CC: Arnaldo Carvalho de Melo <acme@redhat.com>
> CC: David Miller <davem@davemloft.net>
> CC: Stephane Eranian <eranian@google.com>
> CC: stable@kernel.org

Good catch, thanks!