[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>

3 files changed, 10 insertions, 8 deletions

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 7c1f3b1d2ee5..d5bfaba595c7 100644
--- a/include/linux/netlink.h
+++ b/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);
 
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index bfa274ba9ed4..1e04cd464af9 100644
--- a/ipc/mqueue.c
+++ b/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) {
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 260171255576..415c97236f63 100644
--- a/net/netlink/af_netlink.c
+++ b/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)