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Subject: Re: [PATCH percpu#for-next] percpu: clear memory allocated with
 the km allocator
From: Peter Zijlstra <peterz@infradead.org>
To: Tejun Heo <htejun@gmail.com>
Cc: Stephane Eranian <eranian@google.com>,
        Eric Dumazet <eric.dumazet@gmail.com>, linux-kernel@vger.kernel.org,
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Date: Fri, 10 Sep 2010 10:55:18 +0200
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On Fri, 2010-09-10 at 10:52 +0200, Tejun Heo wrote:
> Percpu allocator should clear memory before returning it but the km
> allocator forgot to do it.  Fix it.
> 
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Spotted-by: Peter Zijlstra <peterz@infradead.org>

(fwiw, -tip uses Reported-by)

Acked-by: Peter Zijlstra <peterz@infradead.org>

> ---
>  mm/percpu-km.c |    6 +++++-
>  1 files changed, 5 insertions(+), 1 deletions(-)
> 
> diff --git a/mm/percpu-km.c b/mm/percpu-km.c
> index 7037bc7..89633fe 100644
> --- a/mm/percpu-km.c
> +++ b/mm/percpu-km.c
> @@ -35,7 +35,11 @@
> 
>  static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size)
>  {
> -	/* noop */
> +	unsigned int cpu;
> +
> +	for_each_possible_cpu(cpu)
> +		memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
> +
>  	return 0;
>  }
>