[NETLINK]: Fix unicast timeouts

Commit ed6dcf4a in the history.git tree broke netlink_unicast timeouts
by moving the schedule_timeout() call to a new function that doesn't
propagate the remaining timeout back to the caller. This means on each
retry we start with the full timeout again.

ipc/mqueue.c seems to actually want to wait indefinitely so this
behaviour is retained.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netlink.h

@@ -192,7 +192,7 @@ extern int netlink_unregister_notifier(struct notifier_block *nb);
 /* finegrained unicast helpers: */
 struct sock *netlink_getsockbyfilp(struct file *filp);
 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock,
-		long timeo, struct sock *ssk);
+		      long *timeo, struct sock *ssk);
 void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
 int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
 

ipc/mqueue.c

@@ -1010,6 +1010,8 @@ asmlinkage long sys_mq_notify(mqd_t mqdes,
 			return -EINVAL;
 		}
 		if (notification.sigev_notify == SIGEV_THREAD) {
+			long timeo;
+
 			/* create the notify skb */
 			nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
 			ret = -ENOMEM;
@@ -1038,8 +1040,8 @@ retry:
 				goto out;
 			}
 
-			ret = netlink_attachskb(sock, nc, 0,
-					MAX_SCHEDULE_TIMEOUT, NULL);
+			timeo = MAX_SCHEDULE_TIMEOUT;
+			ret = netlink_attachskb(sock, nc, 0, &timeo, NULL);
 			if (ret == 1)
 		       		goto retry;
 			if (ret) {

net/netlink/af_netlink.c

@@ -752,7 +752,7 @@ struct sock *netlink_getsockbyfilp(struct file *filp)
  * 1: repeat lookup - reference dropped while waiting for socket memory.
  */
 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock,
-		long timeo, struct sock *ssk)
+		      long *timeo, struct sock *ssk)
 {
 	struct netlink_sock *nlk;
 
@@ -761,7 +761,7 @@ int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock,
 	if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
 	    test_bit(0, &nlk->state)) {
 		DECLARE_WAITQUEUE(wait, current);
-		if (!timeo) {
+		if (!*timeo) {
 			if (!ssk || netlink_is_kernel(ssk))
 				netlink_overrun(sk);
 			sock_put(sk);
@@ -775,7 +775,7 @@ int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock,
 		if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
 		     test_bit(0, &nlk->state)) &&
 		    !sock_flag(sk, SOCK_DEAD))
-			timeo = schedule_timeout(timeo);
+			*timeo = schedule_timeout(*timeo);
 
 		__set_current_state(TASK_RUNNING);
 		remove_wait_queue(&nlk->wait, &wait);
@@ -783,7 +783,7 @@ int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock,
 
 		if (signal_pending(current)) {
 			kfree_skb(skb);
-			return sock_intr_errno(timeo);
+			return sock_intr_errno(*timeo);
 		}
 		return 1;
 	}
@@ -877,7 +877,7 @@ retry:
 	if (netlink_is_kernel(sk))
 		return netlink_unicast_kernel(sk, skb);
 
-	err = netlink_attachskb(sk, skb, nonblock, timeo, ssk);
+	err = netlink_attachskb(sk, skb, nonblock, &timeo, ssk);
 	if (err == 1)
 		goto retry;
 	if (err)