Merge tag 'trace-fix-filter-4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing filter fix from Steven Rostedt:
"Vince Weaver reported a warning when he added perf event filters into
his fuzzer tests. There's a missing check of balanced operations when
parenthesis are used, and this triggers a WARN_ON() and when reading
the failure, the filter reports no failure occurred.
The operands were not being checked if they match, this adds that"
* tag 'trace-fix-filter-4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Have filter check for balanced ops
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index ced69da0..7f2e97c 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1369,19 +1369,26 @@
{
int n_normal_preds = 0, n_logical_preds = 0;
struct postfix_elt *elt;
+ int cnt = 0;
list_for_each_entry(elt, &ps->postfix, list) {
- if (elt->op == OP_NONE)
+ if (elt->op == OP_NONE) {
+ cnt++;
continue;
+ }
if (elt->op == OP_AND || elt->op == OP_OR) {
n_logical_preds++;
+ cnt--;
continue;
}
+ if (elt->op != OP_NOT)
+ cnt--;
n_normal_preds++;
+ WARN_ON_ONCE(cnt < 0);
}
- if (!n_normal_preds || n_logical_preds >= n_normal_preds) {
+ if (cnt != 1 || !n_normal_preds || n_logical_preds >= n_normal_preds) {
parse_error(ps, FILT_ERR_INVALID_FILTER, 0);
return -EINVAL;
}