Messages in this thread | | | Date | Fri, 22 Jul 2011 10:44:30 +0200 | From | Tejun Heo <> | Subject | Re: [PATCH 1/1] ptrace: do_wait(traced_leader_killed_by_mt_exec) can block forever |
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Hello,
On Thu, Jul 21, 2011 at 08:00:43PM +0200, Oleg Nesterov wrote: > It is racy, exit_notify() does __wake_up_parent() too. But in the > likely case it triggers the problem: de_thread() does release_task() > and the old leader goes away without the notification, the tracer > sleeps in do_wait() without children/tracees. > > Change de_thread() to do __wake_up_parent(traced_leader->parent). > Since it is already EXIT_DEAD we can do this without ptrace_unlink(), > EXIT_DEAD threads do not exist from do_wait's pov. > > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Nice catch as always. :)
Acked-by: Tejun Heo <tj@kernel.org>
Thanks.
-- tejun
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