Messages in this thread | | | Date | Mon, 4 Aug 2008 15:23:46 +0400 | From | Oleg Nesterov <> | Subject | Re: [PATCH 1/3] posix-timers: don't switch to ->group_leader if ->it_process dies |
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On 08/03, Roland McGrath wrote: > > The key thing that the old code does it to drop the ref to the old task as > soon as it notices.
I thought about this too. But, again, this doesn't actually work. And it is very easy to pin the dead task_struct. The user can just create the SIGEV_THREAD_ID timer and kill the sub-thread (->it_process). Without calling timer_settime() the timer can't notice the death.
(just in case, please note that the next patch doesn't make things worse, when ->group_leader dies the timer should be destroyed soon).
> It may be worthwhile to do that in the case where > send_sigqueue fails.
I think it is better to convert the posix timers to use "struct pid*" instead of "struct task_struct*". This change looks more or less straightforward, and it should fix the problem.
Oleg.
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