tracing: Add generic event-name based remove event method

Add a generic method to remove event from dynamic event
list. This is same as other system under ftrace. You
just need to pass the event name with '!', e.g.

  # echo p:new_grp/new_event _do_fork > dynamic_events

This creates an event, and

  # echo '!p:new_grp/new_event _do_fork' > dynamic_events

Or,

  # echo '!p:new_grp/new_event' > dynamic_events

will remove new_grp/new_event event.

Note that this doesn't check the event prefix (e.g. "p:")
strictly, because the "group/event" name must be unique.

Link: http://lkml.kernel.org/r/154140869774.17322.8887303560398645347.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu 2018-11-05 18:04:57 +09:00 committed by Steven Rostedt (VMware)
parent 7e1413edd6
commit 1ce25e9f6f

View File

@ -37,10 +37,17 @@ int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type)
char *system = NULL, *event, *p;
int ret = -ENOENT;
if (argv[0][1] != ':')
return -EINVAL;
if (argv[0][0] == '-') {
if (argv[0][1] != ':')
return -EINVAL;
event = &argv[0][2];
} else {
event = strchr(argv[0], ':');
if (!event)
return -EINVAL;
event++;
}
event = &argv[0][2];
p = strchr(event, '/');
if (p) {
system = event;
@ -69,7 +76,7 @@ static int create_dyn_event(int argc, char **argv)
struct dyn_event_operations *ops;
int ret;
if (argv[0][0] == '-')
if (argv[0][0] == '-' || argv[0][0] == '!')
return dyn_event_release(argc, argv, NULL);
mutex_lock(&dyn_event_ops_mutex);