+ /*
+ * epoll adds to the wakeup queue at EPOLL_CTL_ADD time only,
+ * so EPOLLEXCLUSIVE is not allowed for a EPOLL_CTL_MOD operation.
+ * Also, we do not currently supported nested exclusive wakeups.
+ */
+ if ((epds.events & EPOLLEXCLUSIVE) && (op == EPOLL_CTL_MOD ||
+ (op == EPOLL_CTL_ADD && is_file_epoll(tf.file))))
+ goto error_tgt_fput;
+