Messages in this thread | | | Date | Wed, 16 Apr 2008 22:16:02 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] cgroup: fix a race condition in manipulating tsk->cg_list |
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On Thu, 17 Apr 2008 13:10:33 +0800 Li Zefan <lizf@cn.fujitsu.com> wrote:
> Andrew Morton wrote: > > On Wed, 16 Apr 2008 21:17:34 -0700 "Paul Menage" <menage@google.com> wrote: > > > >> On Wed, Apr 16, 2008 at 9:11 PM, Andrew Morton > >> <akpm@linux-foundation.org> wrote: > >>> I don't fully understand the race. Both paths hold css_set_lock. > >>> > >>> Can you describe it in more detail please? > >> Task A starts exiting, passes the check for unlinking current->cg_list. > > > > So cgroup_exit() sees !list_empty(tsk->cg_list) > > > > cgroup_exit() sees list_empty(tsk->cg_list), then cgroup_enable_task_cg_list() > links the task to the list, and then the task exited, so the list entry won't > get deleted.
OK.
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