perf/core: Fix locking for children siblings group read

[karo-tx-linux.git] / kernel / events / core.c

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 9747e422ab204c676c05b8b2bb8d9d261eaeafd1..c17c0881fd36aef7200f3991b12bdd5a4322b765 100644 (file)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1452,6 +1452,13 @@ static enum event_type_t get_event_type(struct perf_event *event)
 
        lockdep_assert_held(&ctx->lock);
 
+       /*
+        * It's 'group type', really, because if our group leader is
+        * pinned, so are we.
+        */
+       if (event->group_leader != event)
+               event = event->group_leader;
+
        event_type = event->attr.pinned ? EVENT_PINNED : EVENT_FLEXIBLE;
        if (!ctx->task)
                event_type |= EVENT_CPU;
@@ -4365,7 +4372,9 @@ EXPORT_SYMBOL_GPL(perf_event_read_value);
 static int __perf_read_group_add(struct perf_event *leader,
                                        u64 read_format, u64 *values)
 {
+       struct perf_event_context *ctx = leader->ctx;
        struct perf_event *sub;
+       unsigned long flags;
        int n = 1; /* skip @nr */
        int ret;
 
@@ -4395,12 +4404,15 @@ static int __perf_read_group_add(struct perf_event *leader,
        if (read_format & PERF_FORMAT_ID)
                values[n++] = primary_event_id(leader);
 
+       raw_spin_lock_irqsave(&ctx->lock, flags);
+
        list_for_each_entry(sub, &leader->sibling_list, group_entry) {
                values[n++] += perf_event_count(sub);
                if (read_format & PERF_FORMAT_ID)
                        values[n++] = primary_event_id(sub);
        }
 
+       raw_spin_unlock_irqrestore(&ctx->lock, flags);
        return 0;
 }