From: luoqing <luoqing@kylinos.cn>

The 'err' parameter in sctp_skb_recv_datagram() is never used by any
of its callers. Both sctp_recvmsg() and sctp_ulpevent_read_nxtinfo()
pass the address of a local variable but never check its value after
the function returns, rendering the parameter completely useless.

Remove the unused parameter to simplify the function signature and
eliminate dead code.

Signed-off-by: luoqing <luoqing@kylinos.cn>
---
 include/net/sctp/sctp.h |  2 +-
 net/sctp/socket.c       | 10 +++-------
 net/sctp/ulpevent.c     |  3 +--
 3 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index d50c27812504..b86d50d6b146 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -97,7 +97,7 @@ void sctp_sock_rfree(struct sk_buff *skb);
 
 extern struct percpu_counter sctp_sockets_allocated;
 int sctp_asconf_mgmt(struct sctp_sock *, struct sctp_sockaddr_entry *);
-struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int *);
+struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags);
 
 typedef int (*sctp_callback_t)(struct sctp_endpoint *, struct sctp_transport *, void *);
 void sctp_transport_walk_start(struct rhashtable_iter *iter);
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index c7b9e325ec1c..3804382d78e0 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -2123,7 +2123,7 @@ static int sctp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 		goto out;
 	}
 
-	skb = sctp_skb_recv_datagram(sk, flags, &err);
+	skb = sctp_skb_recv_datagram(sk, flags);
 	if (!skb)
 		goto out;
 
@@ -9082,7 +9082,7 @@ static int sctp_wait_for_packet(struct sock *sk, int *err, long *timeo_p)
  * Note: This is pretty much the same routine as in core/datagram.c
  * with a few changes to make lksctp work.
  */
-struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags, int *err)
+struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags)
 {
 	int error;
 	struct sk_buff *skb;
@@ -9120,17 +9120,13 @@ struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags, int *err)
 		if (sk->sk_shutdown & RCV_SHUTDOWN)
 			break;
 
-
 		/* User doesn't want to wait.  */
 		error = -EAGAIN;
 		if (!timeo)
 			goto no_packet;
-	} while (sctp_wait_for_packet(sk, err, &timeo) == 0);
-
-	return NULL;
+	} while (sctp_wait_for_packet(sk, &error, &timeo) == 0);
 
 no_packet:
-	*err = error;
 	return NULL;
 }
 
diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c
index 8920ca92a011..8ed51a15c3a4 100644
--- a/net/sctp/ulpevent.c
+++ b/net/sctp/ulpevent.c
@@ -1061,9 +1061,8 @@ void sctp_ulpevent_read_nxtinfo(const struct sctp_ulpevent *event,
 				struct sock *sk)
 {
 	struct sk_buff *skb;
-	int err;
 
-	skb = sctp_skb_recv_datagram(sk, MSG_PEEK | MSG_DONTWAIT, &err);
+	skb = sctp_skb_recv_datagram(sk, MSG_PEEK | MSG_DONTWAIT);
 	if (skb != NULL) {
 		__sctp_ulpevent_read_nxtinfo(sctp_skb2event(skb),
 					     msghdr, skb);
-- 
2.25.1