Merge branch 'net-ICW-sendmsg-recvmsg'

Paolo Abeni says:

====================
net: use ICW for sk_proto->{send,recv}msg

This series extends ICW usage to one of the few remaining spots in fast-path
still hitting per packet retpoline overhead, namely the sk_proto->{send,recv}msg
calls.

The first 3 patches in this series refactor the existing code so that applying
the ICW macros is straight-forward: we demux inet_{recv,send}msg in ipv4 and
ipv6 variants so that each of them can easily select the appropriate TCP or UDP
direct call. While at it, a new helper is created to avoid excessive code
duplication, and the current ICWs for inet_{recv,send}msg are adjusted
accordingly.

The last 2 patches really introduce the new ICW use-case, respectively for the
ipv6 and the ipv4 code path.

This gives up to 5% performance improvement under UDP flood, and smaller but
measurable gains for TCP RR workloads.

v1 -> v2:
 - drop inet6_{recv,send}msg declaration from header file,
   prefer ICW macro instead
 - avoid unneeded reclaration for udp_sendmsg, as suggested by Willem
====================

Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/inet_common.h

@@ -25,6 +25,7 @@ int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
 		       int addr_len, int flags);
 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
 		bool kern);
+int inet_send_prepare(struct sock *sk);
 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size);
 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 		      size_t size, int flags);

net/ipv4/af_inet.c

@@ -784,18 +784,28 @@ int inet_getname(struct socket *sock, struct sockaddr *uaddr,
 }
 EXPORT_SYMBOL(inet_getname);
 
-int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
+int inet_send_prepare(struct sock *sk)
 {
-	struct sock *sk = sock->sk;
-
 	sock_rps_record_flow(sk);
 
 	/* We may need to bind the socket. */
 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
 	    inet_autobind(sk))
 		return -EAGAIN;
 
-	return sk->sk_prot->sendmsg(sk, msg, size);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(inet_send_prepare);
+
+int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
+{
+	struct sock *sk = sock->sk;
+
+	if (unlikely(inet_send_prepare(sk)))
+		return -EAGAIN;
+
+	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
+			       sk, msg, size);
 }
 EXPORT_SYMBOL(inet_sendmsg);
 
@@ -804,11 +814,7 @@ ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 {
 	struct sock *sk = sock->sk;
 
-	sock_rps_record_flow(sk);
-
-	/* We may need to bind the socket. */
-	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
-	    inet_autobind(sk))
+	if (unlikely(inet_send_prepare(sk)))
 		return -EAGAIN;
 
 	if (sk->sk_prot->sendpage)
@@ -817,6 +823,8 @@ ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
 }
 EXPORT_SYMBOL(inet_sendpage);
 
+INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
+					  size_t, int, int, int *));
 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 		 int flags)
 {
@@ -827,8 +835,9 @@ int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 	if (likely(!(flags & MSG_ERRQUEUE)))
 		sock_rps_record_flow(sk);
 
-	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
-				   flags & ~MSG_DONTWAIT, &addr_len);
+	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
+			      sk, msg, size, flags & MSG_DONTWAIT,
+			      flags & ~MSG_DONTWAIT, &addr_len);
 	if (err >= 0)
 		msg->msg_namelen = addr_len;
 	return err;

net/ipv6/af_inet6.c

@@ -564,6 +564,39 @@ int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 }
 EXPORT_SYMBOL(inet6_ioctl);
 
+INDIRECT_CALLABLE_DECLARE(int udpv6_sendmsg(struct sock *, struct msghdr *,
+					    size_t));
+int inet6_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
+{
+	struct sock *sk = sock->sk;
+
+	if (unlikely(inet_send_prepare(sk)))
+		return -EAGAIN;
+
+	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udpv6_sendmsg,
+			       sk, msg, size);
+}
+
+INDIRECT_CALLABLE_DECLARE(int udpv6_recvmsg(struct sock *, struct msghdr *,
+					    size_t, int, int, int *));
+int inet6_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+		  int flags)
+{
+	struct sock *sk = sock->sk;
+	int addr_len = 0;
+	int err;
+
+	if (likely(!(flags & MSG_ERRQUEUE)))
+		sock_rps_record_flow(sk);
+
+	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udpv6_recvmsg,
+			      sk, msg, size, flags & MSG_DONTWAIT,
+			      flags & ~MSG_DONTWAIT, &addr_len);
+	if (err >= 0)
+		msg->msg_namelen = addr_len;
+	return err;
+}
+
 const struct proto_ops inet6_stream_ops = {
 	.family		   = PF_INET6,
 	.owner		   = THIS_MODULE,
@@ -580,8 +613,8 @@ const struct proto_ops inet6_stream_ops = {
 	.shutdown	   = inet_shutdown,		/* ok		*/
 	.setsockopt	   = sock_common_setsockopt,	/* ok		*/
 	.getsockopt	   = sock_common_getsockopt,	/* ok		*/
-	.sendmsg	   = inet_sendmsg,		/* ok		*/
-	.recvmsg	   = inet_recvmsg,		/* ok		*/
+	.sendmsg	   = inet6_sendmsg,		/* retpoline's sake */
+	.recvmsg	   = inet6_recvmsg,		/* retpoline's sake */
 #ifdef CONFIG_MMU
 	.mmap		   = tcp_mmap,
 #endif
@@ -614,8 +647,8 @@ const struct proto_ops inet6_dgram_ops = {
 	.shutdown	   = inet_shutdown,		/* ok		*/
 	.setsockopt	   = sock_common_setsockopt,	/* ok		*/
 	.getsockopt	   = sock_common_getsockopt,	/* ok		*/
-	.sendmsg	   = inet_sendmsg,		/* ok		*/
-	.recvmsg	   = inet_recvmsg,		/* ok		*/
+	.sendmsg	   = inet6_sendmsg,		/* retpoline's sake */
+	.recvmsg	   = inet6_recvmsg,		/* retpoline's sake */
 	.mmap		   = sock_no_mmap,
 	.sendpage	   = sock_no_sendpage,
 	.set_peek_off	   = sk_set_peek_off,

net/socket.c

@@ -103,13 +103,6 @@
 #include <net/busy_poll.h>
 #include <linux/errqueue.h>
 
-/* proto_ops for ipv4 and ipv6 use the same {recv,send}msg function */
-#if IS_ENABLED(CONFIG_INET)
-#define INDIRECT_CALL_INET4(f, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
-#else
-#define INDIRECT_CALL_INET4(f, f1, ...) f(__VA_ARGS__)
-#endif
-
 #ifdef CONFIG_NET_RX_BUSY_POLL
 unsigned int sysctl_net_busy_read __read_mostly;
 unsigned int sysctl_net_busy_poll __read_mostly;
@@ -641,10 +634,13 @@ EXPORT_SYMBOL(__sock_tx_timestamp);
 
 INDIRECT_CALLABLE_DECLARE(int inet_sendmsg(struct socket *, struct msghdr *,
 					   size_t));
+INDIRECT_CALLABLE_DECLARE(int inet6_sendmsg(struct socket *, struct msghdr *,
+					    size_t));
 static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg)
 {
-	int ret = INDIRECT_CALL_INET4(sock->ops->sendmsg, inet_sendmsg, sock,
-				      msg, msg_data_left(msg));
+	int ret = INDIRECT_CALL_INET(sock->ops->sendmsg, inet6_sendmsg,
+				     inet_sendmsg, sock, msg,
+				     msg_data_left(msg));
 	BUG_ON(ret == -EIOCBQUEUED);
 	return ret;
 }
@@ -870,12 +866,15 @@ void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
 EXPORT_SYMBOL_GPL(__sock_recv_ts_and_drops);
 
 INDIRECT_CALLABLE_DECLARE(int inet_recvmsg(struct socket *, struct msghdr *,
-					   size_t , int ));
+					   size_t, int));
+INDIRECT_CALLABLE_DECLARE(int inet6_recvmsg(struct socket *, struct msghdr *,
+					    size_t, int));
 static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
 				     int flags)
 {
-	return INDIRECT_CALL_INET4(sock->ops->recvmsg, inet_recvmsg, sock, msg,
-				   msg_data_left(msg), flags);
+	return INDIRECT_CALL_INET(sock->ops->recvmsg, inet6_recvmsg,
+				  inet_recvmsg, sock, msg, msg_data_left(msg),
+				  flags);
 }
 
 /**