From: Arnaldo Carvalho de Melo Date: Mon, 2 Aug 2010 21:59:28 +0000 (-0300) Subject: perf session: Invalidate last_match when removing threads from rb_tree X-Git-Tag: firefly_0821_release~9833^2~776^2~13^2~1 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=70597f21f128b7dd6a2490078bea99d704b6f8c3;p=firefly-linux-kernel-4.4.55.git perf session: Invalidate last_match when removing threads from rb_tree If we receive two PERF_RECORD_EXIT for the same thread, we can end up reusing session->last_match and trying to remove the thread twice from the rb_tree, causing a segfault, so invalidade last_match in perf_session__remove_thread. Receiving two PERF_RECORD_EXIT for the same thread is a bug, but its a harmless one if we make the tool more robust, like this patch does. Cc: Frederic Weisbecker Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Stephane Eranian LKML-Reference: Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 5d2fd52fe7b5..fa9d652c2dc3 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -166,6 +166,7 @@ void perf_session__delete(struct perf_session *self) void perf_session__remove_thread(struct perf_session *self, struct thread *th) { + self->last_match = NULL; rb_erase(&th->rb_node, &self->threads); /* * We may have references to this thread, for instance in some hist_entry