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Commit 15075cac authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
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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: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 50ecf2c3

kernel/trace/trace_events.c

+27 −19
Original line number Diff line number Diff line
@@ -491,19 +491,6 @@ static void t_stop(struct seq_file *m, void *p) 
	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 @@ show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) 
	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 seq_operations show_set_event_seq_ops = { 
};



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 @@ static struct dentry *event_trace_events_dir(void) 
	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 @@ static __init int event_trace_init(void) 
		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");