1 files changed, 10 insertions, 8 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index f80dec3f1875..a1b18c03b4c0 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -159,6 +159,9 @@ static void delayed_put_task_struct(struct rcu_head *rhp)
 {
         struct task_struct *tsk = container_of(rhp, struct task_struct, rcu);
 
+#ifdef CONFIG_PERF_COUNTERS
+        WARN_ON_ONCE(!list_empty(&tsk->perf_counter_ctx.counter_list));
+#endif
         trace_sched_process_free(tsk);
         put_task_struct(tsk);
 }
@@ -977,12 +980,9 @@ static void check_stack_usage(void)
 {
         static DEFINE_SPINLOCK(low_water_lock);
         static int lowest_to_date = THREAD_SIZE;
-        unsigned long *n = end_of_stack(current);
         unsigned long free;
 
-        while (*n == 0)
-                n++;
-        free = (unsigned long)n - (unsigned long)end_of_stack(current);
+        free = stack_not_used(current);
 
         if (free >= lowest_to_date)
                 return;
@@ -1093,10 +1093,6 @@ NORET_TYPE void do_exit(long code)
         tsk->mempolicy = NULL;
 #endif
 #ifdef CONFIG_FUTEX
-        /*
-         * This must happen late, after the PID is not
-         * hashed anymore:
-         */
         if (unlikely(!list_empty(&tsk->pi_state_list)))
                 exit_pi_state_list(tsk);
         if (unlikely(current->pi_state_cache))
@@ -1363,6 +1359,12 @@ static int wait_task_zombie(struct task_struct *p, int options,
          */
         read_unlock(&tasklist_lock);
 
+        /*
+         * Flush inherited counters to the parent - before the parent
+         * gets woken up by child-exit notifications.
+         */
+        perf_counter_exit_task(p);
+
         retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
         status = (p->signal->flags & SIGNAL_GROUP_EXIT)
                 ? p->signal->group_exit_code : p->exit_code;