tracing: Miscellaneous fixes for trace_array ref counting
Some error paths did not handle ref counting properly, and some trace files need
ref counting.
Link: http://lkml.kernel.org/r/1374171524-11948-1-git-send-email-azl@google.com
Cc: stable@vger.kernel.org # 3.10
Cc: Vaibhav Nagarnaik <vnagarnaik@google.com>
Cc: David Sharp <dhsharp@google.com>
Cc: Alexander Z Lam <lambchop468@gmail.com>
Signed-off-by: Alexander Z Lam <azl@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 7d85429..7a75cb2 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1218,6 +1218,7 @@
static int ftrace_event_avail_open(struct inode *inode, struct file *file);
static int ftrace_event_set_open(struct inode *inode, struct file *file);
+static int ftrace_event_release(struct inode *inode, struct file *file);
static const struct seq_operations show_event_seq_ops = {
.start = t_start,
@@ -1245,7 +1246,7 @@
.read = seq_read,
.write = ftrace_event_write,
.llseek = seq_lseek,
- .release = seq_release,
+ .release = ftrace_event_release,
};
static const struct file_operations ftrace_enable_fops = {
@@ -1323,6 +1324,15 @@
return ret;
}
+static int ftrace_event_release(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+
+ trace_array_put(tr);
+
+ return seq_release(inode, file);
+}
+
static int
ftrace_event_avail_open(struct inode *inode, struct file *file)
{
@@ -1336,12 +1346,19 @@
{
const struct seq_operations *seq_ops = &show_set_event_seq_ops;
struct trace_array *tr = inode->i_private;
+ int ret;
+
+ if (trace_array_get(tr) < 0)
+ return -ENODEV;
if ((file->f_mode & FMODE_WRITE) &&
(file->f_flags & O_TRUNC))
ftrace_clear_events(tr);
- return ftrace_event_open(inode, file, seq_ops);
+ ret = ftrace_event_open(inode, file, seq_ops);
+ if (ret < 0)
+ trace_array_put(tr);
+ return ret;
}
static struct event_subsystem *