From 6d54057d76e25c91165cda0e6e007f1811faa2be Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 27 Jan 2011 22:33:26 -0500 Subject: 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 Signed-off-by: Steven Rostedt diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 36d4010..7275f03 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -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); -- cgit v0.10.2