net: add option to enable error queue packets waking select

Currently, when a socket receives something on the error queue it only wakes up
the socket on select if it is in the "read" list, that is the socket has
something to read. It is useful also to wake the socket if it is in the error
list, which would enable software to wait on error queue packets without waking
up for regular data on the socket. The main use case is for receiving
timestamped transmit packets which return the timestamp to the socket via the
error queue. This enables an application to select on the socket for the error
queue only instead of for the regular traffic.

-v2-
* Added the SO_SELECT_ERR_QUEUE socket option to every architechture specific file
* Modified every socket poll function that checks error queue

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Cc: Jeffrey Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Matthew Vick <matthew.vick@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

23 files changed, 53 insertions, 6 deletions

diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index c5195524d1ef..eee6ea76bdaf 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -79,4 +79,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/avr32/include/uapi/asm/socket.h b/arch/avr32/include/uapi/asm/socket.h
index 51c6401582ea..37401f535126 100644
--- a/arch/avr32/include/uapi/asm/socket.h
+++ b/arch/avr32/include/uapi/asm/socket.h
@@ -72,4 +72,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* __ASM_AVR32_SOCKET_H */
diff --git a/arch/cris/include/uapi/asm/socket.h b/arch/cris/include/uapi/asm/socket.h
index 50692b738c75..ba409c9947bc 100644
--- a/arch/cris/include/uapi/asm/socket.h
+++ b/arch/cris/include/uapi/asm/socket.h
@@ -74,6 +74,8 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_SOCKET_H */
 
 
diff --git a/arch/frv/include/uapi/asm/socket.h b/arch/frv/include/uapi/asm/socket.h
index 595391f0f98c..31dbb5d8e13d 100644
--- a/arch/frv/include/uapi/asm/socket.h
+++ b/arch/frv/include/uapi/asm/socket.h
@@ -72,5 +72,7 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_SOCKET_H */
 
diff --git a/arch/h8300/include/uapi/asm/socket.h b/arch/h8300/include/uapi/asm/socket.h
index 43e32621da7d..5d1c6d0870e6 100644
--- a/arch/h8300/include/uapi/asm/socket.h
+++ b/arch/h8300/include/uapi/asm/socket.h
@@ -72,4 +72,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/ia64/include/uapi/asm/socket.h b/arch/ia64/include/uapi/asm/socket.h
index c567adc8bea5..6b4329f18b29 100644
--- a/arch/ia64/include/uapi/asm/socket.h
+++ b/arch/ia64/include/uapi/asm/socket.h
@@ -81,4 +81,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_IA64_SOCKET_H */
diff --git a/arch/m32r/include/uapi/asm/socket.h b/arch/m32r/include/uapi/asm/socket.h
index 519afa2755db..2a3b59e0e171 100644
--- a/arch/m32r/include/uapi/asm/socket.h
+++ b/arch/m32r/include/uapi/asm/socket.h
@@ -72,4 +72,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_M32R_SOCKET_H */
diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
index 47132f44c955..3b211507be7f 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -90,4 +90,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/mn10300/include/uapi/asm/socket.h b/arch/mn10300/include/uapi/asm/socket.h
index 5c7c7c988544..b4ce844c9391 100644
--- a/arch/mn10300/include/uapi/asm/socket.h
+++ b/arch/mn10300/include/uapi/asm/socket.h
@@ -72,4 +72,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
index 526e4b9aece0..70c512a386f7 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -71,6 +71,8 @@
 
 #define SO_LOCK_FILTER		0x4025
 
+#define SO_SELECT_ERR_QUEUE	0x4026
+
 /* O_NONBLOCK clashes with the bits used for socket types.  Therefore we
  * have to define SOCK_NONBLOCK to a different value here.
  */
diff --git a/arch/powerpc/include/uapi/asm/socket.h b/arch/powerpc/include/uapi/asm/socket.h
index a26dcaece509..a36daf3c6f9a 100644
--- a/arch/powerpc/include/uapi/asm/socket.h
+++ b/arch/powerpc/include/uapi/asm/socket.h
@@ -79,4 +79,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif	/* _ASM_POWERPC_SOCKET_H */
diff --git a/arch/s390/include/uapi/asm/socket.h b/arch/s390/include/uapi/asm/socket.h
index f99eea7fff0f..2dacb306835c 100644
--- a/arch/s390/include/uapi/asm/socket.h
+++ b/arch/s390/include/uapi/asm/socket.h
@@ -78,4 +78,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
index cbbad74b2e06..89f49b68a21c 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -68,6 +68,8 @@
 
 #define SO_LOCK_FILTER		0x0028
 
+#define SO_SELECT_ERR_QUEUE	0x0029
+
 /* Security levels - as per NRL IPv6 - don't actually do anything */
 #define SO_SECURITY_AUTHENTICATION		0x5001
 #define SO_SECURITY_ENCRYPTION_TRANSPORT	0x5002
diff --git a/arch/xtensa/include/uapi/asm/socket.h b/arch/xtensa/include/uapi/asm/socket.h
index 35905cb6e419..a8f44f50e651 100644
--- a/arch/xtensa/include/uapi/asm/socket.h
+++ b/arch/xtensa/include/uapi/asm/socket.h
@@ -83,4 +83,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif	/* _XTENSA_SOCKET_H */
diff --git a/include/net/sock.h b/include/net/sock.h
index 14f6e9d19dc7..08f05f964737 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -667,6 +667,7 @@ enum sock_flags {
 		     * user-space instead.
 		     */
 	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
+	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
 };
 
 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index 4ef3acbba5da..c5d2e3a1cf68 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -74,4 +74,6 @@
 
 #define SO_LOCK_FILTER		44
 
+#define SO_SELECT_ERR_QUEUE	45
+
 #endif /* __ASM_GENERIC_SOCKET_H */
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index d3ee69b35a78..409902f892ff 100644
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -422,7 +422,8 @@ unsigned int bt_sock_poll(struct file *file, struct socket *sock,
 		return bt_accept_poll(sk);
 
 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
-		mask |= POLLERR;
+		mask |= POLLERR |
+			sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0;
 
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		mask |= POLLRDHUP | POLLIN | POLLRDNORM;
diff --git a/net/core/datagram.c b/net/core/datagram.c
index 368f9c3f9dc6..36da5b663514 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -749,7 +749,9 @@ unsigned int datagram_poll(struct file *file, struct socket *sock,
 
 	/* exceptional events? */
 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
-		mask |= POLLERR;
+		mask |= POLLERR |
+			sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0;
+
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		mask |= POLLRDHUP | POLLIN | POLLRDNORM;
 	if (sk->sk_shutdown == SHUTDOWN_MASK)
diff --git a/net/core/sock.c b/net/core/sock.c
index a19e728d5fb6..2ff5f3619a8d 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -907,6 +907,10 @@ set_rcvbuf:
 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
 		break;
 
+	case SO_SELECT_ERR_QUEUE:
+		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
+		break;
+
 	default:
 		ret = -ENOPROTOOPT;
 		break;
@@ -1160,6 +1164,10 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
 		break;
 
+	case SO_SELECT_ERR_QUEUE:
+		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
+		break;
+
 	default:
 		return -ENOPROTOOPT;
 	}
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index a7d11ffe4284..f0550a38f295 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -1461,7 +1461,8 @@ unsigned int iucv_sock_poll(struct file *file, struct socket *sock,
 		return iucv_accept_poll(sk);
 
 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
-		mask |= POLLERR;
+		mask |= POLLERR |
+			sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0;
 
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		mask |= POLLRDHUP;
diff --git a/net/nfc/llcp/sock.c b/net/nfc/llcp/sock.c
index f1b377e247fe..2d55e8a45958 100644
--- a/net/nfc/llcp/sock.c
+++ b/net/nfc/llcp/sock.c
@@ -521,7 +521,8 @@ static unsigned int llcp_sock_poll(struct file *file, struct socket *sock,
 		return llcp_accept_poll(sk);
 
 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
-		mask |= POLLERR;
+		mask |= POLLERR |
+			sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0;
 
 	if (!skb_queue_empty(&sk->sk_receive_queue))
 		mask |= POLLIN | POLLRDNORM;
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index b9070736b8d9..dd21ae3013d8 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -6185,7 +6185,8 @@ unsigned int sctp_poll(struct file *file, struct socket *sock, poll_table *wait)
 
 	/* Is there any exceptional events?  */
 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
-		mask |= POLLERR;
+		mask |= POLLERR |
+			sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0;
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		mask |= POLLRDHUP | POLLIN | POLLRDNORM;
 	if (sk->sk_shutdown == SHUTDOWN_MASK)
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 971282b6f6a3..fb7a63ff71a5 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2196,7 +2196,9 @@ static unsigned int unix_dgram_poll(struct file *file, struct socket *sock,
 
 	/* exceptional events? */
 	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
-		mask |= POLLERR;
+		mask |= POLLERR |
+			sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? POLLPRI : 0;
+
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		mask |= POLLRDHUP | POLLIN | POLLRDNORM;
 	if (sk->sk_shutdown == SHUTDOWN_MASK)