/* Removes a registered user return notifier. Must be called from atomic context, and from the same cpu registration occured in.  */
void user_return_notifier_unregister(struct user_return_notifier *urn)
/* Removes a registered user return notifier. Must be called from atomic context, and from the same cpu registration occured in.  */
void user_return_notifier_unregister(struct user_return_notifier *urn)
{
	hlist_del(&urn->link);
	if (hlist_empty(&__get_cpu_var(return_notifier_list)))
		clear_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY);
}