[tip:perf/core] tracing: Check for allocation failure in __tracing_open()

[tip-bot for Dan Carpenter <dan.carpenter@oracle.com>]

Commit-ID:  93574fcc5b50cc7b8834698acb2ce947e5b6a5dc
Gitweb:     http://git.kernel.org/tip/93574fcc5b50cc7b8834698acb2ce947e5b6a5dc
Author:     Dan Carpenter <dan.carpenter@oracle.com>
AuthorDate: Wed, 11 Jul 2012 09:35:08 +0300
Committer:  Steven Rostedt <rostedt@goodmis.org>
CommitDate: Wed, 11 Jul 2012 19:56:26 -0400

tracing: Check for allocation failure in __tracing_open()

Clean up and return -ENOMEM on if the kzalloc() fails.

This also prevents a potential crash, as the pointer that failed to
allocate would be later used.

Link: http://lkml.kernel.org/r/20120711063507.GF11812@elgon.mountain

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 814ff30..a120f98 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2390,6 +2390,9 @@ __tracing_open(struct inode *inode, struct file *file)
 
 	iter->buffer_iter = kzalloc(sizeof(*iter->buffer_iter) * num_possible_cpus(),
 				    GFP_KERNEL);
+	if (!iter->buffer_iter)
+		goto release;
+
 	/*
 	 * We make a copy of the current tracer to avoid concurrent
 	 * changes on it while we are reading.
@@ -2451,6 +2454,7 @@ __tracing_open(struct inode *inode, struct file *file)
 	mutex_unlock(&trace_types_lock);
 	kfree(iter->trace);
 	kfree(iter->buffer_iter);
+release:
 	seq_release_private(inode, file);
 	return ERR_PTR(-ENOMEM);
 }