tracing: add back the available_events file

The event directory files type and available_types were no longer
needed with the new TRACE_EVENT_FORMAT macros, they were deleted.
But by accident the available_events file was also removed.
This patch brings it back.

Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 85ec10fbb38dc1c9cf8b841caae9253dde135aec..769dfd00fc859a1b4ba78b7e30696c651d5b904e 100644 (file)
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -428,6 +428,13 @@ static const struct seq_operations show_set_event_seq_ops = {
        .stop = t_stop,
 };
 
+static const struct file_operations ftrace_avail_fops = {
+       .open = ftrace_event_seq_open,
+       .read = seq_read,
+       .llseek = seq_lseek,
+       .release = seq_release,
+};
+
 static const struct file_operations ftrace_set_event_fops = {
        .open = ftrace_event_seq_open,
        .read = seq_read,
@@ -569,6 +576,13 @@ static __init int event_trace_init(void)
        if (!d_tracer)
                return 0;
 
+       entry = debugfs_create_file("available_events", 0444, d_tracer,
+                                   (void *)&show_event_seq_ops,
+                                   &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);