tipc: fix broken tipc_poll() function

In commit ae236fb208a6 ("tipc: receive group membership events via
member socket") we broke the tipc_poll() function by checking the
state of the receive queue before the call to poll_sock_wait(), while
relying that state afterwards, when it might have changed.

We restore this in this commit.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 3 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 2bbab4fe2f53..357954ceb25c 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -714,7 +714,6 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
                               poll_table *wait)
 {
         struct sock *sk = sock->sk;
-        struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
         struct tipc_sock *tsk = tipc_sk(sk);
         struct tipc_group *grp = tsk->group;
         u32 revents = 0;
@@ -733,7 +732,7 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
                 /* fall thru' */
         case TIPC_LISTEN:
         case TIPC_CONNECTING:
-                if (skb)
+                if (!skb_queue_empty(&sk->sk_receive_queue))
                         revents |= POLLIN | POLLRDNORM;
                 break;
         case TIPC_OPEN:
@@ -742,7 +741,7 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
                                 revents |= POLLOUT;
                 if (!tipc_sk_type_connectionless(sk))
                         break;
-                if (!skb)
+                if (skb_queue_empty(&sk->sk_receive_queue))
                         break;
                 revents |= POLLIN | POLLRDNORM;
                 break;