Commit 6d54057d authored Jan 27, 2011 by Steven Rostedt Committed by Steven Rostedt Feb 07, 2011

tracing/filter: Have no filter return a match



The n_preds field of a file can change at anytime, and even can become
zero, just as the filter is about to be processed by an event.
In the case that is zero on entering the filter, return 1, telling
the caller the event matchs and should be trace.

Also use a variable and assign it with ACCESS_ONCE() such that the
count stays consistent within the function.

Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent 075de90c

kernel/trace/trace_events_filter.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -383,9 +383,14 @@ int filter_match_preds(struct event_filter filter, void rec)
		int match, top = 0, val1 = 0, val2 = 0;
		int stack[MAX_FILTER_PRED];
		struct filter_pred *pred;
		int n_preds = ACCESS_ONCE(filter->n_preds);
		int i;

		for (i = 0; i < filter->n_preds; i++) {
		/* no filter is considered a match */
		if (!n_preds)
		return 1;

		for (i = 0; i < n_preds; i++) {
		pred = filter->preds[i];
		if (!pred->pop_n) {
		match = pred->fn(pred, rec, val1, val2);