aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--kernel/trace/trace_events.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 1d7b6d0..50dc8b2 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -840,7 +840,7 @@ enum {
static void *f_next(struct seq_file *m, void *v, loff_t *pos)
{
- struct ftrace_event_call *call = m->private;
+ struct ftrace_event_call *call = event_file_data(m->private);
struct list_head *common_head = &ftrace_common_fields;
struct list_head *head = trace_get_fields(call);
struct list_head *node = v;
@@ -872,7 +872,7 @@ static void *f_next(struct seq_file *m, void *v, loff_t *pos)
static int f_show(struct seq_file *m, void *v)
{
- struct ftrace_event_call *call = m->private;
+ struct ftrace_event_call *call = event_file_data(m->private);
struct ftrace_event_field *field;
const char *array_descriptor;
@@ -925,6 +925,11 @@ static void *f_start(struct seq_file *m, loff_t *pos)
void *p = (void *)FORMAT_HEADER;
loff_t l = 0;
+ /* ->stop() is called even if ->start() fails */
+ mutex_lock(&event_mutex);
+ if (!event_file_data(m->private))
+ return ERR_PTR(-ENODEV);
+
while (l < *pos && p)
p = f_next(m, p, &l);
@@ -933,6 +938,7 @@ static void *f_start(struct seq_file *m, loff_t *pos)
static void f_stop(struct seq_file *m, void *p)
{
+ mutex_unlock(&event_mutex);
}
static const struct seq_operations trace_format_seq_ops = {
@@ -944,7 +950,6 @@ static const struct seq_operations trace_format_seq_ops = {
static int trace_format_open(struct inode *inode, struct file *file)
{
- struct ftrace_event_call *call = inode->i_private;
struct seq_file *m;
int ret;
@@ -953,7 +958,7 @@ static int trace_format_open(struct inode *inode, struct file *file)
return ret;
m = file->private_data;
- m->private = call;
+ m->private = file;
return 0;
}