From: Masami Hiramatsu (Google) <[email protected]>
In calc_stack(), when encountering '||' or '&&' (where str[i+1] == str[i]),
the loop sets 'is_pred = false' and continues without advancing 'i' past
the second character of the operator. On the next iteration, the second '|'
or '&' sees str[i+1] != str[i], breaks out of the switch statement, and is
counted as the start of a new predicate (incrementing nr_preds and setting
is_pred = true).
Consequently, a trailing logical operator (e.g. 'common_pid == 1 ||') is
counted as having 2 predicates instead of 1, and any subsequent non-space
character before a delimiter fails to increment nr_preds.
Increment 'i' when matching '||' or '&&' so the entire two-character
operator is skipped.
Fixes: 80765597bc58 ("tracing: Rewrite filter logic to be simpler and faster")
Cc: [email protected]
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
---
kernel/trace/trace_events_filter.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/trace/trace_events_filter.c
b/kernel/trace/trace_events_filter.c
index 96eac7ccd488..e734d8664444 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -2207,6 +2207,7 @@ static int calc_stack(const char *str, int *parens, int
*preds, int *err)
case '&':
if (str[i+1] != str[i])
break;
+ i++;
is_pred = false;
continue;
case '(':
