X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=kernel%2Fevents%2Fcore.c;h=d7d71d6ec97278cf60fa5b13e79a80bff27b6af2;hb=bcc66c0b8881f88459f9ac21038455bcafacdc6e;hp=f85c0154b333a02c6a611cf8eca55362ab7f7eaf;hpb=8e53ed10f871a077cc61374c74e0bbab25264208;p=cascardo%2Flinux.git

diff --git a/kernel/events/core.c b/kernel/events/core.c
index f85c0154b333..d7d71d6ec972 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -253,9 +253,9 @@ perf_cgroup_match(struct perf_event *event)
 	return !event->cgrp || event->cgrp == cpuctx->cgrp;
 }
 
-static inline void perf_get_cgroup(struct perf_event *event)
+static inline bool perf_tryget_cgroup(struct perf_event *event)
 {
-	css_get(&event->cgrp->css);
+	return css_tryget(&event->cgrp->css);
 }
 
 static inline void perf_put_cgroup(struct perf_event *event)
@@ -484,7 +484,11 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event,
 	event->cgrp = cgrp;
 
 	/* must be done before we fput() the file */
-	perf_get_cgroup(event);
+	if (!perf_tryget_cgroup(event)) {
+		event->cgrp = NULL;
+		ret = -ENOENT;
+		goto out;
+	}
 
 	/*
 	 * all events in a group must monitor