perf namespace: Protect reading thread's namespace (6584140b) · Commits · 戴 / test

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:

tools/perf/util/thread.c

+13 −2

Original line number	Diff line number	Diff line
		@@ -133,7 +133,7 @@ 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;
		@@ -141,10 +141,21 @@ 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)