2 files changed, 11 insertions, 3 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index f495c0147240..311b4dc785a1 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -938,9 +938,7 @@ struct perf_cpu_context {
        struct list_head                rotation_list;
        int                             jiffies_interval;
        struct pmu                      *active_pmu;
-#ifdef CONFIG_CGROUP_PERF
        struct perf_cgroup              *cgrp;
-#endif
 };
 struct perf_output_handle {
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 3472bb1a070c..0c714226ae0c 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -941,6 +941,7 @@ static void perf_group_attach(struct perf_event *event)
 static void
 list_del_event(struct perf_event *event, struct perf_event_context *ctx)
 {
+        struct perf_cpu_context *cpuctx;
        /*
         * We can have double detach due to exit/hot-unplug + close.
         */
@@ -949,8 +950,17 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx)
        event->attach_state &= ~PERF_ATTACH_CONTEXT;
-        if (is_cgroup_event(event))
+        if (is_cgroup_event(event)) {
                ctx->nr_cgroups--;
+                cpuctx = __get_cpu_context(ctx);
+                /*
+                 * if there are no more cgroup events
+                 * then cler cgrp to avoid stale pointer
+                 * in update_cgrp_time_from_cpuctx()
+                 */
+                if (!ctx->nr_cgroups)
+                        cpuctx->cgrp = NULL;
+        }
        ctx->nr_events--;
        if (event->attr.inherit_stat)