Messages in this thread | | | Date | Wed, 7 Mar 2012 21:35:29 +0530 | Subject | Re: [PATCH 2/2] mm/linux-next: Fix rcu locking in vm_is_stack | From | Siddhesh Poyarekar <> |
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On Wed, Mar 7, 2012 at 9:08 PM, Oleg Nesterov <oleg@redhat.com> wrote: > Once again. You have the task_struct *task. It exits, > but task->thread_group->next still points to another thread T. Now suppose > that T exits too. But task->thread_group->next was not changed, it still > points to T. RCU grace period passes, T is freed. > > After that you take rcu_read_lock(), but it is too late! >next points to > the already freed/reused memory. How can list_first_entry_rcu() help?
Ahh, I completely misunderstood your point. Thanks for the detailed explanation.
> And. Imho it is not good to have the (afaics exactly?) same code in > mm/nommu.c, even with the same names. Why it is not possible to make > a single definition?
Yes it is the same code. I put the code in both memory.c and nommu.c because I thought they fit in there logically. I can find a common place for it.
-- Siddhesh Poyarekar http://siddhesh.in
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