diff options
| -rw-r--r-- | kernel/trace/trace_uprobe.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index cbab487e8522..8541fa1494ae 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1226,9 +1226,6 @@ __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) { struct perf_event *event; - if (filter->nr_systemwide) - return true; - list_for_each_entry(event, &filter->perf_events, hw.tp_list) { if (event->hw.target->mm == mm) return true; @@ -1353,6 +1350,13 @@ static bool uprobe_perf_filter(struct uprobe_consumer *uc, tu = container_of(uc, struct trace_uprobe, consumer); filter = tu->tp.event->filter; + /* + * speculative short-circuiting check to avoid unnecessarily taking + * filter->rwlock below, if the uprobe has system-wide consumer + */ + if (READ_ONCE(filter->nr_systemwide)) + return true; + read_lock(&filter->rwlock); ret = __uprobe_perf_filter(filter, mm); read_unlock(&filter->rwlock); |