[PATCH 086/118] tracing: Check return value of tracing_init_dentry()

[Luis Henriques]

3.5.7.12 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Namhyung Kim <namhyung.kim at lge.com>

commit ed6f1c996bfe4b6e520cf7a74b51cd6988d84420 upstream.

Check return value and bail out if it's NULL.

Link: http://lkml.kernel.org/r/1365553093-10180-2-git-send-email-namhyung@kernel.org

Cc: Frederic Weisbecker <fweisbec at gmail.com>
Cc: Namhyung Kim <namhyung.kim at lge.com>
Signed-off-by: Namhyung Kim <namhyung at kernel.org>
Signed-off-by: Steven Rostedt <rostedt at goodmis.org>
[ luis: adjust context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 kernel/trace/trace.c       | 2 ++
 kernel/trace/trace_stack.c | 2 ++
 kernel/trace/trace_stat.c  | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 28e2b14..0ae8b32 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4832,6 +4832,8 @@ static __init int tracer_init_debugfs(void)
 	trace_access_lock_init();
 
 	d_tracer = tracing_init_dentry();
+	if (!d_tracer)
+		return 0;
 
 	trace_create_file("tracing_enabled", 0644, d_tracer,
 			&global_trace, &tracing_ctrl_fops);
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 0cdcba3..8298997 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -433,6 +433,8 @@ static __init int stack_trace_init(void)
 	struct dentry *d_tracer;
 
 	d_tracer = tracing_init_dentry();
+	if (!d_tracer)
+		return 0;
 
 	trace_create_file("stack_max_size", 0644, d_tracer,
 			&max_stack_size, &stack_max_size_fops);
diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index 96cffb2..847f88a 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -307,6 +307,8 @@ static int tracing_stat_init(void)
 	struct dentry *d_tracing;
 
 	d_tracing = tracing_init_dentry();
+	if (!d_tracing)
+		return 0;
 
 	stat_dir = debugfs_create_dir("trace_stat", d_tracing);
 	if (!stat_dir)
-- 
1.8.1.2