From: Frederic Weisbecker Date: Thu, 24 Apr 2025 16:11:28 +0000 (+0200) Subject: perf: Fix confusing aux iteration X-Git-Tag: v6.16-rc1~196^2~22 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=881097c0549f3818f5aa31af8ccb49213bd99bed;p=thirdparty%2Fkernel%2Flinux.git perf: Fix confusing aux iteration While an event tears down all links to it as an aux, the iteration happens on the event's group leader instead of the group itself. If the event is a group leader, it has no effect because the event is also its own group leader. But otherwise there would be a risk to detach all the siblings events from the wrong group leader. It just happens to work because each sibling's aux link is tested against the right event before proceeding. Also the ctx lock is the same for the events and their group leader so the iteration is safe. Yet the iteration is confusing. Clarify the actual intent. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20250424161128.29176-5-frederic@kernel.org --- diff --git a/kernel/events/core.c b/kernel/events/core.c index e0ca4a88beb55..b8461074600bd 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2171,7 +2171,7 @@ static void perf_put_aux_event(struct perf_event *event) * If the event is an aux_event, tear down all links to * it from other events. */ - for_each_sibling_event(iter, event->group_leader) { + for_each_sibling_event(iter, event) { if (iter->aux_event != event) continue;