On 06/03, Ben Blum wrote: > > On Wed, Jun 02, 2010 at 10:58:55PM +0200, Oleg Nesterov wrote: > > Hmm. The usage of ->thread_group in ->can_attach() methods doesn't > > look safe to me... but currently bool threadgroup is always false. > > I recall putting a rcu_read_lock() around that part and being assured > that made it safe. But I don't remember the details. Maybe taking > tasklist_lock is necessary? rcu_read_lock() is not enough, see another email I sent. Once again. rcu_read_lock() list_for_each_rcu(tsk->thread_group) assumes that at least tsk->thread_group->next can't point to nowhere, this is not true. This memory can go away _before_ we take rcu lock. Oleg. _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
