From: Masami Hiramatsu (Google) <[email protected]>
In filter_pred_##size##_cpumask(), if the event's scalar CPU value is
out of range (cpu >= nr_cpu_ids), it unconditionally returns 0.
However, if the predicate operation is OP_NE (e.g., field != CPUS{0,1}),
an out-of-range CPU cannot match any valid CPU in the user-provided
cpumask and the condition is satisfied. Returning 0 produces a false
negative.
Return "pred->op == OP_NE" instead of 0 when cpu >= nr_cpu_ids.
Fixes: 3cbec9d7b93d ("tracing/filters: Enable filtering a scalar field by a
cpumask")
Cc: [email protected]
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
---
kernel/trace/trace_events_filter.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/trace_events_filter.c
b/kernel/trace/trace_events_filter.c
index 617bc3c0bb0c..3f56e234a02c 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -759,7 +759,7 @@ static int filter_pred_##size##_cpumask(struct filter_pred
*pred, void *event) \
unsigned int cpu = *addr;
\
\
if (cpu >= nr_cpu_ids)
\
- return 0;
\
+ return pred->op == OP_NE;
\
\
return do_filter_scalar_cpumask(pred->op, cpu, pred->mask);
\
}
