perf events: Fix ring_buffer_wakeup() brown paperbag bug
authorWill Deacon <will.deacon@arm.com>
Tue, 13 Dec 2011 19:40:45 +0000 (20:40 +0100)
committerIngo Molnar <mingo@elte.hu>
Wed, 14 Dec 2011 07:44:53 +0000 (08:44 +0100)
commit44b7f4b98d8877e2a4427f2a2f2e42ae8227a58f
tree929c7c5c177fa072216445de276592843ebae4d8
parent373da0a2a33018d560afcb2c77f8842985d79594
perf events: Fix ring_buffer_wakeup() brown paperbag bug

Commit 10c6db11 ("perf: Fix loss of notification with multi-event")
seems to unconditionally dereference event->rb in the wakeup handler,
this is wrong, there might not be a buffer attached.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20111213152651.GP20297@mudshark.cambridge.arm.com
[ minor edits ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kernel/events/core.c