From f5f6b255a253e2c3132ca283e9090a6343bfb719 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Wed, 29 Jan 2020 12:59:23 -0600 Subject: tracing: Add synth_event_delete() create_or_delete_synth_event() contains code to delete a synthetic event, which would be useful on its own - specifically, it would be useful to allow event-creating modules to call it separately. Separate out the delete code from that function and create an exported function named synth_event_delete(). Link: http://lkml.kernel.org/r/050db3b06df7f0a4b8a2922da602d1d879c7c1c2.1580323897.git.zanussi@kernel.org Acked-by: Masami Hiramatsu Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware) --- include/linux/trace_events.h | 2 ++ kernel/trace/trace_events_hist.c | 57 +++++++++++++++++++++++++++++----------- 2 files changed, 43 insertions(+), 16 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 8d621a73c97e..25fe743bcbaf 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -354,6 +354,8 @@ extern struct trace_event_file *trace_get_event_file(const char *instance, const char *event); extern void trace_put_event_file(struct trace_event_file *file); +extern int synth_event_delete(const char *name); + /* * Event file flags: * ENABLED - The event is enabled diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index c322826e0726..21e316732700 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1360,29 +1360,54 @@ static int __create_synth_event(int argc, const char *name, const char **argv) goto out; } +static int destroy_synth_event(struct synth_event *se) +{ + int ret; + + if (se->ref) + ret = -EBUSY; + else { + ret = unregister_synth_event(se); + if (!ret) { + dyn_event_remove(&se->devent); + free_synth_event(se); + } + } + + return ret; +} + +/** + * synth_event_delete - Delete a synthetic event + * @event_name: The name of the new sythetic event + * + * Delete a synthetic event that was created with synth_event_create(). + * + * Return: 0 if successful, error otherwise. + */ +int synth_event_delete(const char *event_name) +{ + struct synth_event *se = NULL; + int ret = -ENOENT; + + mutex_lock(&event_mutex); + se = find_synth_event(event_name); + if (se) + ret = destroy_synth_event(se); + mutex_unlock(&event_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(synth_event_delete); + static int create_or_delete_synth_event(int argc, char **argv) { const char *name = argv[0]; - struct synth_event *event = NULL; int ret; /* trace_run_command() ensures argc != 0 */ if (name[0] == '!') { - mutex_lock(&event_mutex); - event = find_synth_event(name + 1); - if (event) { - if (event->ref) - ret = -EBUSY; - else { - ret = unregister_synth_event(event); - if (!ret) { - dyn_event_remove(&event->devent); - free_synth_event(event); - } - } - } else - ret = -ENOENT; - mutex_unlock(&event_mutex); + ret = synth_event_delete(name + 1); return ret; } -- cgit v1.2.3