All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH] perf/core: Fix reversed NULL check in perf_event_groups_less()
@ 2020-03-12 10:56 ` Dan Carpenter
  0 siblings, 0 replies; 7+ messages in thread
From: Dan Carpenter @ 2020-03-12 10:56 UTC (permalink / raw)
  To: Peter Zijlstra, Ian Rogers
  Cc: Ingo Molnar, Arnaldo Carvalho de Melo, Mark Rutland,
	Alexander Shishkin, Jiri Olsa, Namhyung Kim, linux-kernel,
	kernel-janitors

This NULL check is reversed so it leads to a Smatch warning and
presumably a NULL dereference.

    kernel/events/core.c:1598 perf_event_groups_less()
    error: we previously assumed 'right->cgrp->css.cgroup' could be null
	(see line 1590)

Fixes: 95ed6c707f26 ("perf/cgroup: Order events in RB tree by cgroup id")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 kernel/events/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 6a47c3e54fe9..607c04ec7cfa 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1587,7 +1587,7 @@ perf_event_groups_less(struct perf_event *left, struct perf_event *right)
 			 */
 			return true;
 		}
-		if (!right->cgrp || right->cgrp->css.cgroup) {
+		if (!right->cgrp || !right->cgrp->css.cgroup) {
 			/*
 			 * Right has no cgroup but left does, no cgroups come
 			 * first.
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2020-03-21  2:24 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-12 10:56 [PATCH] perf/core: Fix reversed NULL check in perf_event_groups_less() Dan Carpenter
2020-03-12 10:56 ` Dan Carpenter
2020-03-13 12:27 ` Peter Zijlstra
2020-03-13 12:27   ` Peter Zijlstra
2020-03-21  2:24   ` Ian Rogers
2020-03-21  2:24     ` Ian Rogers
2020-03-20 12:58 ` [tip: perf/core] " tip-bot2 for Dan Carpenter

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.