Messages in this thread | | | Date | Thu, 29 May 2014 12:52:53 -0400 | From | Sasha Levin <> | Subject | Re: perf: use after free in perf_remove_from_context |
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On 05/29/2014 12:50 PM, Peter Zijlstra wrote: >> > >> > So the only caller to sync_child_event() is that loop. According to what you said >> > it should be safe to remove that mutex lock, but doing that triggers a list >> > corruption: >> > >> > [ 1204.341887] WARNING: CPU: 20 PID: 12839 at lib/list_debug.c:62 __list_del_entry+0xa1/0xe0() >> > [ 1204.347597] list_del corruption. next->prev should be ffff8806ca68b108, but was ffff88051a67c398 >> > [...] >> > >> > I don't see how that would happen :/ > No, what I said is that the mutex in perf_event_exit_task() should be > sufficient to guard the list iteration calling __perf_event_exit_task(). > > Ading the RCU was a bit of paranoia..
Oh, my bad, I thought you referred to the mutex lock in sync_child_event().
Thanks, Sasha
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