kernel/trace/trace_events_trigger.c

42  * trigger has a filter associated with it, rec will checked against
43  * the filter and if the record matches the trigger will be invoked.
64 	struct event_filter *filter;
76 		filter = rcu_dereference_sched(data->filter);
77 		if (filter && !filter_match_preds(filter, rec))
526  * If an event has triggers and any of those triggers has a filter or
540 		if (data->filter || event_command_post_trigger(data->cmd_ops) ||
658  *   [trigger] [if filter]
668  *   param             - text following cmd and ':' and stripped of filter
669  *   filter            - the optional filter text following (and including) 'if'
678  *     - 'if pid == 0' is the filter
684  *     - there is no filter
690  *     - 'if prio > 50' is the filter
697  *     - there is no filter
703  *     - there is no filter
721  * it has special requirements for handling the filter.
759  * event_trigger_separate_filter - separate an event trigger from a filter
760  * @param_and_filter: String containing trigger and possibly filter
762  * @filter: outparam, will be filled with a pointer to the filter
765  * Given a param string of the form '[trigger] [if filter]', this
766  * function separates the filter from the trigger and returns the
767  * trigger in @param and the filter in @filter.  Either the @param
768  * or the @filter may be set to NULL by this function - if not set to
770  * filter.
779  * and assumes param just contains a filter and there's nothing else
785 				  char **filter, bool param_required)
789 	*param = *filter = NULL;
800 	 * below. Otherwise we assume what's left is a filter and
801 	 * return it as the filter string for the caller to deal with.
804 		*filter = param_and_filter;
809 	 * Separate the param from the filter (param [if filter]).
811 	 * param and an optional filter.
816 	 * Here we have a filter, though it may be empty.
819 		*filter = skip_spaces(param_and_filter);
820 		if (!**filter)
821 			*filter = NULL;
864 	RCU_INIT_POINTER(trigger_data->filter, NULL);
902  * event_trigger_set_filter - set an event trigger's filter
905  * @param: The string containing the filter
908  * Set the filter for the trigger.  If the filter is NULL, just return
925  * event_trigger_reset_filter - reset an event trigger's filter
929  * Reset the filter for the trigger to no filter.
986  * @param_and_filter: The param and filter portion of the string used to register the trigger
1002 	char *param, *filter;
1008 	ret = event_trigger_separate_filter(param_and_filter, &param, &filter, false);
1028 	ret = event_trigger_set_filter(cmd_ops, file, filter, trigger_data);
1052  * @filter_str: The filter string for the trigger, NULL to remove filter
1056  * Common implementation for event command filter parsing and filter
1062  * Also used to remove a filter (if filter_str = NULL).
1071 	struct event_filter *filter = NULL, *tmp;
1075 	if (!filter_str) /* clear the current filter */
1086 	/* The filter is for the 'trigger' event, not the triggered event */
1088 				  filter_str, true, &filter);
1091 	if (filter) {
1092 		kfree(filter->filter_string);
1093 		filter->filter_string = NULL;
1097 	 * If create_event_filter() fails, filter still needs to be freed.
1098 	 * Which the calling code will do with data->filter.
1101 	tmp = rcu_access_pointer(data->filter);
1103 	rcu_assign_pointer(data->filter, filter);
1107 		 * Make sure the call is done with the filter.
1108 		 * It is possible that a filter could fail at boot up,
1123 			free_event_filter(rcu_access_pointer(data->filter));
1124 			data->filter = NULL;
1771 	char *param, *filter;
1783 	ret = event_trigger_separate_filter(param_and_filter, &param, &filter, true);
1838 	ret = event_trigger_set_filter(cmd_ops, file, filter, trigger_data);