From: Namhyung Kim namhyung@kernel.org
[ Upstream commit 6584140ba9e6762dd7ec73795243289b914f31f9 ]
It seems that the current code lacks holding the namespace lock in thread__namespaces(). Otherwise it can see inconsistent results.
Signed-off-by: Namhyung Kim namhyung@kernel.org Cc: Hari Bathini hbathini@linux.vnet.ibm.com Cc: Jiri Olsa jolsa@redhat.com Cc: Krister Johansen kjlx@templeofstupid.com Link: http://lkml.kernel.org/r/20190522053250.207156-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/thread.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c index 2048d393ece6..56007a7e0b4d 100644 --- a/tools/perf/util/thread.c +++ b/tools/perf/util/thread.c @@ -128,7 +128,7 @@ void thread__put(struct thread *thread) } }
-struct namespaces *thread__namespaces(const struct thread *thread) +static struct namespaces *__thread__namespaces(const struct thread *thread) { if (list_empty(&thread->namespaces_list)) return NULL; @@ -136,10 +136,21 @@ struct namespaces *thread__namespaces(const struct thread *thread) return list_first_entry(&thread->namespaces_list, struct namespaces, list); }
+struct namespaces *thread__namespaces(const struct thread *thread) +{ + struct namespaces *ns; + + down_read((struct rw_semaphore *)&thread->namespaces_lock); + ns = __thread__namespaces(thread); + up_read((struct rw_semaphore *)&thread->namespaces_lock); + + return ns; +} + static int __thread__set_namespaces(struct thread *thread, u64 timestamp, struct namespaces_event *event) { - struct namespaces *new, *curr = thread__namespaces(thread); + struct namespaces *new, *curr = __thread__namespaces(thread);
new = namespaces__new(event); if (!new)