[PATCH 2/3] tracing: Allow NOT to filter AND and OR clauses

[Steven Rostedt <rostedt@goodmis.org>]

[-- Attachment #1: 0002-tracing-Allow-NOT-to-filter-AND-and-OR-clauses.patch --]
[-- Type: text/plain, Size: 1422 bytes --]

From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>

Add support to allow not "!" for and (&&) and (||). That is:

 !(field1 == X && field2 == Y)

Where the value of the full clause will be notted.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_events_filter.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index e6a33db83856..ced69da0ff55 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -489,9 +489,10 @@ static int process_ops(struct filter_pred *preds,
 		if (!WARN_ON_ONCE(!pred->fn))
 			match = pred->fn(pred, rec);
 		if (!!match == type)
-			return match;
+			break;
 	}
-	return match;
+	/* If not of not match is equal to not of not, then it is a match */
+	return !!match == !op->not;
 }
 
 struct filter_match_preds_data {
@@ -740,10 +741,10 @@ static int filter_set_pred(struct event_filter *filter,
 		 * then this op can be folded.
 		 */
 		if (left->index & FILTER_PRED_FOLD &&
-		    (left->op == dest->op ||
+		    ((left->op == dest->op && !left->not) ||
 		     left->left == FILTER_PRED_INVALID) &&
 		    right->index & FILTER_PRED_FOLD &&
-		    (right->op == dest->op ||
+		    ((right->op == dest->op && !right->not) ||
 		     right->left == FILTER_PRED_INVALID))
 			dest->index |= FILTER_PRED_FOLD;
 
-- 
2.1.3