af_unix: do not report POLLOUT on listeners
poll(POLLOUT) on a listener should not report fd is ready for
a write().
This would break some applications using poll() and pfd.events = -1,
as they would not block in poll()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Alan Burlison <Alan.Burlison@oracle.com>
Tested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 94f6582..aaa0b58 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -326,9 +326,10 @@
return s;
}
-static inline int unix_writable(struct sock *sk)
+static int unix_writable(const struct sock *sk)
{
- return (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
+ return sk->sk_state != TCP_LISTEN &&
+ (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
}
static void unix_write_space(struct sock *sk)