3.2.85-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Michael Ellerman <[email protected]> commit 724b6daa13e100067c30cfc4d1ad06629609dc4e upstream. In perf_event_for_each() we call a function on an event, and then iterate over the siblings of the event. However we don't call the function on the siblings, we call it repeatedly on the original event - it seems "obvious" that we should be calling it with sibling as the argument. It looks like this broke in commit 75f937f24bd9 ("Fix ctx->mutex vs counter->mutex inversion"). The only effect of the bug is that the PERF_IOC_FLAG_GROUP parameter to the ioctls doesn't work. Signed-off-by: Michael Ellerman <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- kernel/events/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3326,7 +3326,7 @@ static void perf_event_for_each(struct p perf_event_for_each_child(event, func); func(event); list_for_each_entry(sibling, &event->sibling_list, group_entry) - perf_event_for_each_child(event, func); + perf_event_for_each_child(sibling, func); mutex_unlock(&ctx->mutex); }
