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>
This commit is contained in:
Steven Rostedt 2011-01-27 22:33:26 -05:00 committed by Steven Rostedt
parent 075de90c46
commit 6d54057d76
1 changed files with 6 additions and 1 deletions

View File

@ -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);