From: Tejun Heo <tj@kernel.org>
To: Li Zefan <lizefan@huawei.com>
Cc: Cgroups <cgroups@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
"Kirill A. Shutemov" <kirill@shutemov.name>
Subject: Re: [PATCH v2] cgroup: fix cgroup_rmdir() vs close(eventfd) race
Date: Mon, 18 Feb 2013 09:16:47 -0800 [thread overview]
Message-ID: <20130218171647.GD17414@htj.dyndns.org> (raw)
In-Reply-To: <5121C647.7030608@huawei.com>
On Mon, Feb 18, 2013 at 02:12:23PM +0800, Li Zefan wrote:
> commit 205a872bd6f9a9a09ef035ef1e90185a8245cc58 ("cgroup: fix lockdep
> warning for event_control") solved a deadlock by introducing a new
> bug.
>
> Move cgrp->event_list to a temporary list doesn't mean you can traverse
> this list locklessly, because at the same time cgroup_event_wake() can
> be called and remove the event from the list. The result of this race
> is disastrous.
>
> We adopt the way how kvm irqfd code implements race-free event removal,
> which is now described in the comments in cgroup_event_wake().
>
> Signed-off-by: Li Zefan <lizefan@huawei.com>
Applied to cgroup/for-3.9.
Thanks.
--
tejun
next prev parent reply other threads:[~2013-02-18 17:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-18 6:12 [PATCH v2] cgroup: fix cgroup_rmdir() vs close(eventfd) race Li Zefan
2013-02-18 10:36 ` Kirill A. Shutemov
2013-02-18 10:39 ` Li Zefan
2013-02-18 17:16 ` Tejun Heo [this message]
2013-02-18 17:18 ` Tejun Heo
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