perf: Fix event group context move
[~shefty/rdma-dev.git] / kernel / events / core.c
index 301079d06f24ebe44081a286766436de104a3a91..7b6646a8c067b4ec9143585746fd2b2bccb73f0c 100644 (file)
@@ -907,6 +907,15 @@ list_add_event(struct perf_event *event, struct perf_event_context *ctx)
                ctx->nr_stat++;
 }
 
+/*
+ * Initialize event state based on the perf_event_attr::disabled.
+ */
+static inline void perf_event__state_init(struct perf_event *event)
+{
+       event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF :
+                                             PERF_EVENT_STATE_INACTIVE;
+}
+
 /*
  * Called at perf_event creation and when events are attached/detached from a
  * group.
@@ -6179,8 +6188,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
        event->overflow_handler = overflow_handler;
        event->overflow_handler_context = context;
 
-       if (attr->disabled)
-               event->state = PERF_EVENT_STATE_OFF;
+       perf_event__state_init(event);
 
        pmu = NULL;
 
@@ -6609,9 +6617,17 @@ SYSCALL_DEFINE5(perf_event_open,
 
                mutex_lock(&gctx->mutex);
                perf_remove_from_context(group_leader);
+
+               /*
+                * Removing from the context ends up with disabled
+                * event. What we want here is event in the initial
+                * startup state, ready to be add into new context.
+                */
+               perf_event__state_init(group_leader);
                list_for_each_entry(sibling, &group_leader->sibling_list,
                                    group_entry) {
                        perf_remove_from_context(sibling);
+                       perf_event__state_init(sibling);
                        put_ctx(gctx);
                }
                mutex_unlock(&gctx->mutex);