From: Vlastimil Babka <vbabka@suse.cz>
To: Tejun Heo <tj@kernel.org>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>,
Alexei Starovoitov <ast@kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Christoph Lameter <cl@linux.com>,
Linux-MM layout <linux-mm@kvack.org>,
Marco Grassi <marco.gra@gmail.com>,
kernel-team@fb.com
Subject: Re: [PATCH percpu/for-4.7-fixes 2/2] percpu: fix synchronization between synchronous map extension and chunk destruction
Date: Thu, 26 May 2016 11:48:41 +0200 [thread overview]
Message-ID: <0613d173-2ff1-a904-9611-0c6fc254f45e@suse.cz> (raw)
In-Reply-To: <20160525154525.GF3354@mtj.duckdns.org>
On 05/25/2016 05:45 PM, Tejun Heo wrote:
> For non-atomic allocations, pcpu_alloc() can try to extend the area
> map synchronously after dropping pcpu_lock; however, the extension
> wasn't synchronized against chunk destruction and the chunk might get
> freed while extension is in progress.
>
> This patch fixes the bug by putting most of non-atomic allocations
> under pcpu_alloc_mutex to synchronize against pcpu_balance_work which
> is responsible for async chunk management including destruction.
>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Reported-and-tested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
> Reported-by: Vlastimil Babka <vbabka@suse.cz>
> Reported-by: Sasha Levin <sasha.levin@oracle.com>
> Cc: stable@vger.kernel.org # v3.18+
> Fixes: 1a4d76076cda ("percpu: implement asynchronous chunk population")
Didn't spot any problems this time.
Thanks
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prev parent reply other threads:[~2016-05-26 9:48 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-17 16:58 bpf: use-after-free in array_map_alloc Sasha Levin
2016-04-17 17:29 ` Alexei Starovoitov
2016-04-17 22:45 ` Sasha Levin
2016-05-23 12:01 ` Vlastimil Babka
2016-05-23 12:07 ` Vlastimil Babka
2016-05-23 21:35 ` Tejun Heo
2016-05-23 22:13 ` Alexei Starovoitov
2016-05-24 8:40 ` Vlastimil Babka
2016-05-24 15:30 ` Tejun Heo
2016-05-24 19:04 ` Tejun Heo
2016-05-24 20:43 ` Alexei Starovoitov
2016-05-25 15:44 ` [PATCH percpu/for-4.7-fixes 1/2] percpu: fix synchronization between chunk->map_extend_work and chunk destruction Tejun Heo
2016-05-26 9:19 ` Vlastimil Babka
2016-05-26 19:21 ` Tejun Heo
2016-05-26 20:48 ` Vlastimil Babka
2016-05-25 15:45 ` [PATCH percpu/for-4.7-fixes 2/2] percpu: fix synchronization between synchronous map extension " Tejun Heo
2016-05-26 9:48 ` Vlastimil Babka [this message]
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