Commit 5487b6ce authored by Daniel Bristot de Oliveira's avatar Daniel Bristot de Oliveira Committed by Steven Rostedt (Google)
Browse files

rtla/trace: Add trace event filter helpers 

Add a set of helper functions to allow rtla tools to filter events
in the trace instance.

Link: https://lkml.kernel.org/r/12623b1684684549d53b90f4bf66fae44584fd14.1646247211.git.bristot@kernel.org



Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Clark Williams <williams@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarDaniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 1a754893

tools/tracing/rtla/src/trace.c

+83 −0
Original line number Diff line number Diff line
@@ -204,6 +204,8 @@ static void trace_events_free(struct trace_events *events) 


		tevent = tevent->next;



		if (free_event->filter)

			free(free_event->filter);

		if (free_event->trigger)

			free(free_event->trigger);

		free(free_event->system);
@@ -237,6 +239,21 @@ struct trace_events *trace_event_alloc(const char *event_string) 
	return tevent;

}



/*

 * trace_event_add_filter - record an event filter

 */

int trace_event_add_filter(struct trace_events *event, char *filter)

{

	if (event->filter)

		free(event->filter);



	event->filter = strdup(filter);

	if (!event->filter)

		return 1;



	return 0;

}



/*

 * trace_event_add_trigger - record an event trigger action

 */
@@ -252,6 +269,33 @@ int trace_event_add_trigger(struct trace_events *event, char *trigger) 
	return 0;

}



/*

 * trace_event_disable_filter - disable an event filter

 */

static void trace_event_disable_filter(struct trace_instance *instance,

				       struct trace_events *tevent)

{

	char filter[1024];

	int retval;



	if (!tevent->filter)

		return;



	if (!tevent->filter_enabled)

		return;



	debug_msg("Disabling %s:%s filter %s\n", tevent->system,

		  tevent->event ? : "*", tevent->filter);



	snprintf(filter, 1024, "!%s\n", tevent->filter);



	retval = tracefs_event_file_write(instance->inst, tevent->system,

					  tevent->event, "filter", filter);

	if (retval < 0)

		err_msg("Error disabling %s:%s filter %s\n", tevent->system,

			tevent->event ? : "*", tevent->filter);

}



/*

 * trace_event_disable_trigger - disable an event trigger

 */
@@ -293,6 +337,7 @@ void trace_events_disable(struct trace_instance *instance, 
	while (tevent) {

		debug_msg("Disabling event %s:%s\n", tevent->system, tevent->event ? : "*");

		if (tevent->enabled) {

			trace_event_disable_filter(instance, tevent);

			trace_event_disable_trigger(instance, tevent);

			tracefs_event_disable(instance->inst, tevent->system, tevent->event);

		}
@@ -302,6 +347,41 @@ void trace_events_disable(struct trace_instance *instance, 
	}

}



/*

 * trace_event_enable_filter - enable an event filter associated with an event

 */

static int trace_event_enable_filter(struct trace_instance *instance,

				     struct trace_events *tevent)

{

	char filter[1024];

	int retval;



	if (!tevent->filter)

		return 0;



	if (!tevent->event) {

		err_msg("Filter %s applies only for single events, not for all %s:* events\n",

			tevent->filter, tevent->system);

		return 1;

	}



	snprintf(filter, 1024, "%s\n", tevent->filter);



	debug_msg("Enabling %s:%s filter %s\n", tevent->system,

		  tevent->event ? : "*", tevent->filter);



	retval = tracefs_event_file_write(instance->inst, tevent->system,

					  tevent->event, "filter", filter);

	if (retval < 0) {

		err_msg("Error enabling %s:%s filter %s\n", tevent->system,

			tevent->event ? : "*", tevent->filter);

		return 1;

	}



	tevent->filter_enabled = 1;

	return 0;

}



/*

 * trace_event_enable_trigger - enable an event trigger associated with an event

 */
@@ -356,6 +436,9 @@ int trace_events_enable(struct trace_instance *instance, 
			return 1;

		}



		retval = trace_event_enable_filter(instance, tevent);

		if (retval)

			return 1;



		retval = trace_event_enable_trigger(instance, tevent);

		if (retval)

tools/tracing/rtla/src/trace.h

+3 −0
Original line number Diff line number Diff line
@@ -6,8 +6,10 @@ struct trace_events { 
	struct trace_events *next;

	char *system;

	char *event;

	char *filter;

	char *trigger;

	char enabled;

	char filter_enabled;

	char trigger_enabled;

};
@@ -43,4 +45,5 @@ void trace_events_destroy(struct trace_instance *instance, 
int trace_events_enable(struct trace_instance *instance,

			  struct trace_events *events);



int trace_event_add_filter(struct trace_events *event, char *filter);

int trace_event_add_trigger(struct trace_events *event, char *trigger);