Messages in this thread | | | Date | Mon, 18 Feb 2013 09:17:56 -0800 | From | Tejun Heo <> | Subject | Re: [PATCH v3] cgroup: fix cgroup_rmdir() vs close(eventfd) race |
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On Mon, Feb 18, 2013 at 06:56:14PM +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(). > > v3: > - call eventfd_signal() no matter it's eventfd close or cgroup removal > that removes the cgroup event. > > Acked-by: Kirill A. Shutemov <kirill@shutemov.name> > Signed-off-by: Li Zefan <lizefan@huawei.com>
Dropped v2 and applied this one to cgroup/for-3.9.
Thanks.
-- tejun
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