tracing: Separate open function from set_event and available_events
The open function used by available_events is the same as set_event even
though it uses different seq functions. This causes a side effect of
writing into available_events clearing all events, even though
available_events is suppose to be read only.
There's no reason to keep a single function for just the open and have
both use different functions for everything else. It is a little
confusing and causes strange behavior. Just have each have their own
function.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index dec47e7..cb2df3b 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -491,19 +491,6 @@
mutex_unlock(&event_mutex);
}
-static int
-ftrace_event_seq_open(struct inode *inode, struct file *file)
-{
- const struct seq_operations *seq_ops;
-
- if ((file->f_mode & FMODE_WRITE) &&
- (file->f_flags & O_TRUNC))
- ftrace_clear_events();
-
- seq_ops = inode->i_private;
- return seq_open(file, seq_ops);
-}
-
static ssize_t
event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
loff_t *ppos)
@@ -980,6 +967,9 @@
return r;
}
+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 const struct seq_operations show_event_seq_ops = {
.start = t_start,
.next = t_next,
@@ -995,14 +985,14 @@
};
static const struct file_operations ftrace_avail_fops = {
- .open = ftrace_event_seq_open,
+ .open = ftrace_event_avail_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static const struct file_operations ftrace_set_event_fops = {
- .open = ftrace_event_seq_open,
+ .open = ftrace_event_set_open,
.read = seq_read,
.write = ftrace_event_write,
.llseek = seq_lseek,
@@ -1078,6 +1068,26 @@
return d_events;
}
+static int
+ftrace_event_avail_open(struct inode *inode, struct file *file)
+{
+ const struct seq_operations *seq_ops = &show_event_seq_ops;
+
+ return seq_open(file, seq_ops);
+}
+
+static int
+ftrace_event_set_open(struct inode *inode, struct file *file)
+{
+ const struct seq_operations *seq_ops = &show_set_event_seq_ops;
+
+ if ((file->f_mode & FMODE_WRITE) &&
+ (file->f_flags & O_TRUNC))
+ ftrace_clear_events();
+
+ return seq_open(file, seq_ops);
+}
+
static struct dentry *
event_subsystem_dir(const char *name, struct dentry *d_events)
{
@@ -1508,15 +1518,13 @@
return 0;
entry = debugfs_create_file("available_events", 0444, d_tracer,
- (void *)&show_event_seq_ops,
- &ftrace_avail_fops);
+ NULL, &ftrace_avail_fops);
if (!entry)
pr_warning("Could not create debugfs "
"'available_events' entry\n");
entry = debugfs_create_file("set_event", 0644, d_tracer,
- (void *)&show_set_event_seq_ops,
- &ftrace_set_event_fops);
+ NULL, &ftrace_set_event_fops);
if (!entry)
pr_warning("Could not create debugfs "
"'set_event' entry\n");