X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fkernel%2Ftrace%2Ftrace_events_filter.c;fp=kernel%2Fkernel%2Ftrace%2Ftrace_events_filter.c;h=52adf02d761914211f843d6942efd1f43b81c5aa;hb=fdb8b20906f3546ba6c2f9f0686d8a5189516ba3;hp=7f2e97ce71a7d12a9b2ed5e703969e635f320a57;hpb=cc84a1f21026270463b580f2564f9d71912b20db;p=kvmfornfv.git

diff --git a/kernel/kernel/trace/trace_events_filter.c b/kernel/kernel/trace/trace_events_filter.c
index 7f2e97ce7..52adf02d7 100644
--- a/kernel/kernel/trace/trace_events_filter.c
+++ b/kernel/kernel/trace/trace_events_filter.c
@@ -1056,6 +1056,9 @@ static void parse_init(struct filter_parse_state *ps,
 
 static char infix_next(struct filter_parse_state *ps)
 {
+	if (!ps->infix.cnt)
+		return 0;
+
 	ps->infix.cnt--;
 
 	return ps->infix.string[ps->infix.tail++];
@@ -1071,6 +1074,9 @@ static char infix_peek(struct filter_parse_state *ps)
 
 static void infix_advance(struct filter_parse_state *ps)
 {
+	if (!ps->infix.cnt)
+		return;
+
 	ps->infix.cnt--;
 	ps->infix.tail++;
 }
@@ -1385,7 +1391,9 @@ static int check_preds(struct filter_parse_state *ps)
 		if (elt->op != OP_NOT)
 			cnt--;
 		n_normal_preds++;
-		WARN_ON_ONCE(cnt < 0);
+		/* all ops should have operands */
+		if (cnt < 0)
+			break;
 	}
 
 	if (cnt != 1 || !n_normal_preds || n_logical_preds >= n_normal_preds) {