patch for waitqueue issue (libos-nuse/net-next-nuse#45)

wq.patch

diff --git a/arch/lib/sched.c b/arch/lib/sched.c
index 98a568a..3f59028 100644
--- a/arch/lib/sched.c
+++ b/arch/lib/sched.c
@@ -164,17 +164,35 @@ void finish_wait(wait_queue_head_t *q, wait_queue_t *wait)
 	if (!list_empty(&wait->task_list))
 		list_del_init(&wait->task_list);
 }
+#if 1
 int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync,
 			     void *key)
 {
-	int ret = default_wake_function(wait, mode, sync, key);
+	int ret;
+
+	ret = default_wake_function(wait, mode, sync, key);
 
 	if (ret && (wait->task_list.prev != LIST_POISON2))
 		list_del_init(&wait->task_list);
 
 	return ret;
 }
+#else
+int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync,
+			     void *key)
+{
+	wait_queue_t copy_wait;
+	int ret;
 
+	memcpy(&copy_wait, wait, sizeof(wait_queue_t));
+	ret = default_wake_function(&copy_wait, mode, sync, key);
+
+	if (ret && (copy_wait.task_list.prev != LIST_POISON2))
+		list_del_init(&copy_wait.task_list);
+
+	return ret;
+}
+#endif
 int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
 {
 	wait->flags |= WQ_FLAG_WOKEN;