function-graph: Fix seqfile memory leak

Every time we cat set_graph_function, we leak memory allocated
by seq_open().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A67D907.2010500@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 12 insertions, 3 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 4521c77d1a1a..1f3ec2afa511 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2596,6 +2596,14 @@ ftrace_graph_open(struct inode *inode, struct file *file)
 }
 
 static int
+ftrace_graph_release(struct inode *inode, struct file *file)
+{
+        if (file->f_mode & FMODE_READ)
+                seq_release(inode, file);
+        return 0;
+}
+
+static int
 ftrace_set_func(unsigned long *array, int *idx, char *buffer)
 {
         struct dyn_ftrace *rec;
@@ -2724,9 +2732,10 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
 }
 
 static const struct file_operations ftrace_graph_fops = {
-        .open = ftrace_graph_open,
-        .read = seq_read,
-        .write = ftrace_graph_write,
+        .open           = ftrace_graph_open,
+        .read           = seq_read,
+        .write          = ftrace_graph_write,
+        .release        = ftrace_graph_release,
 };
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */