1 files changed, 68 insertions, 73 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 22909036b9bc..1b5fb6103ded 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -43,7 +43,7 @@
 #include <linux/slab.h>
 #include <linux/poll.h>
 #include <linux/fcntl.h>
-#include <asm/semaphore.h>
+#include <linux/mutex.h>
 #include <asm/string.h>
 #include <asm/atomic.h>
 #include <net/sock.h>
@@ -63,7 +63,7 @@
 struct tipc_sock {
 	struct sock sk;
 	struct tipc_port *p;
-	struct semaphore sem;
+	struct mutex lock;
 };
 
 #define tipc_sk(sk) ((struct tipc_sock*)sk)
@@ -102,44 +102,6 @@ static void sock_unlock(struct tipc_sock* tsock)
 }
 
 /**
- * pollmask - determine the current set of poll() events for a socket
- * @sock: socket structure
- *
- * TIPC sets the returned events as follows:
- * a) POLLRDNORM and POLLIN are set if the socket's receive queue is non-empty
- *    or if a connection-oriented socket is does not have an active connection
- *    (i.e. a read operation will not block).
- * b) POLLOUT is set except when a socket's connection has been terminated
- *    (i.e. a write operation will not block).
- * c) POLLHUP is set when a socket's connection has been terminated.
- *
- * IMPORTANT: The fact that a read or write operation will not block does NOT
- * imply that the operation will succeed!
- *
- * Returns pollmask value
- */
-
-static u32 pollmask(struct socket *sock)
-{
-	u32 mask;
-
-	if ((skb_queue_len(&sock->sk->sk_receive_queue) != 0) ||
-	    (sock->state == SS_UNCONNECTED) ||
-	    (sock->state == SS_DISCONNECTING))
-		mask = (POLLRDNORM | POLLIN);
-	else
-		mask = 0;
-
-	if (sock->state == SS_DISCONNECTING)
-		mask |= POLLHUP;
-	else
-		mask |= POLLOUT;
-
-	return mask;
-}
-
-
-/**
  * advance_queue - discard first buffer in queue
  * @tsock: TIPC socket
  */
@@ -217,7 +179,7 @@ static int tipc_create(struct net *net, struct socket *sock, int protocol)
 	tsock->p = port;
 	port->usr_handle = tsock;
 
-	init_MUTEX(&tsock->sem);
+	mutex_init(&tsock->lock);
 
 	dbg("sock_create: %x\n",tsock);
 
@@ -253,9 +215,9 @@ static int release(struct socket *sock)
 	dbg("sock_delete: %x\n",tsock);
 	if (!tsock)
 		return 0;
-	down(&tsock->sem);
+	mutex_lock(&tsock->lock);
 	if (!sock->sk) {
-		up(&tsock->sem);
+		mutex_unlock(&tsock->lock);
 		return 0;
 	}
 
@@ -288,7 +250,7 @@ static int release(struct socket *sock)
 		atomic_dec(&tipc_queue_size);
 	}
 
-	up(&tsock->sem);
+	mutex_unlock(&tsock->lock);
 
 	sock_put(sk);
 
@@ -315,7 +277,7 @@ static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len)
 	struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
 	int res;
 
-	if (down_interruptible(&tsock->sem))
+	if (mutex_lock_interruptible(&tsock->lock))
 		return -ERESTARTSYS;
 
 	if (unlikely(!uaddr_len)) {
@@ -346,7 +308,7 @@ static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len)
 		res = tipc_withdraw(tsock->p->ref, -addr->scope,
 				    &addr->addr.nameseq);
 exit:
-	up(&tsock->sem);
+	mutex_unlock(&tsock->lock);
 	return res;
 }
 
@@ -367,7 +329,7 @@ static int get_name(struct socket *sock, struct sockaddr *uaddr,
 	struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
 	u32 res;
 
-	if (down_interruptible(&tsock->sem))
+	if (mutex_lock_interruptible(&tsock->lock))
 		return -ERESTARTSYS;
 
 	*uaddr_len = sizeof(*addr);
@@ -380,7 +342,7 @@ static int get_name(struct socket *sock, struct sockaddr *uaddr,
 		res = tipc_ownidentity(tsock->p->ref, &addr->addr.id);
 	addr->addr.name.domain = 0;
 
-	up(&tsock->sem);
+	mutex_unlock(&tsock->lock);
 	return res;
 }
 
@@ -390,15 +352,47 @@ static int get_name(struct socket *sock, struct sockaddr *uaddr,
  * @sock: socket for which to calculate the poll bits
  * @wait: ???
  *
- * Returns the pollmask
+ * Returns pollmask value
+ *
+ * COMMENTARY:
+ * It appears that the usual socket locking mechanisms are not useful here
+ * since the pollmask info is potentially out-of-date the moment this routine
+ * exits.  TCP and other protocols seem to rely on higher level poll routines
+ * to handle any preventable race conditions, so TIPC will do the same ...
+ *
+ * TIPC sets the returned events as follows:
+ * a) POLLRDNORM and POLLIN are set if the socket's receive queue is non-empty
+ *    or if a connection-oriented socket is does not have an active connection
+ *    (i.e. a read operation will not block).
+ * b) POLLOUT is set except when a socket's connection has been terminated
+ *    (i.e. a write operation will not block).
+ * c) POLLHUP is set when a socket's connection has been terminated.
+ *
+ * IMPORTANT: The fact that a read or write operation will not block does NOT
+ * imply that the operation will succeed!
  */
 
 static unsigned int poll(struct file *file, struct socket *sock,
 			 poll_table *wait)
 {
-	poll_wait(file, sock->sk->sk_sleep, wait);
-	/* NEED LOCK HERE? */
-	return pollmask(sock);
+	struct sock *sk = sock->sk;
+	u32 mask;
+
+	poll_wait(file, sk->sk_sleep, wait);
+
+	if (!skb_queue_empty(&sk->sk_receive_queue) ||
+	    (sock->state == SS_UNCONNECTED) ||
+	    (sock->state == SS_DISCONNECTING))
+		mask = (POLLRDNORM | POLLIN);
+	else
+		mask = 0;
+
+	if (sock->state == SS_DISCONNECTING)
+		mask |= POLLHUP;
+	else
+		mask |= POLLOUT;
+
+	return mask;
 }
 
 /**
@@ -477,7 +471,7 @@ static int send_msg(struct kiocb *iocb, struct socket *sock,
 		}
 	}
 
-	if (down_interruptible(&tsock->sem))
+	if (mutex_lock_interruptible(&tsock->lock))
 		return -ERESTARTSYS;
 
 	if (needs_conn) {
@@ -523,7 +517,7 @@ static int send_msg(struct kiocb *iocb, struct socket *sock,
 		}
 		if (likely(res != -ELINKCONG)) {
 exit:
-			up(&tsock->sem);
+			mutex_unlock(&tsock->lock);
 			return res;
 		}
 		if (m->msg_flags & MSG_DONTWAIT) {
@@ -562,7 +556,7 @@ static int send_packet(struct kiocb *iocb, struct socket *sock,
 	if (unlikely(dest))
 		return send_msg(iocb, sock, m, total_len);
 
-	if (down_interruptible(&tsock->sem)) {
+	if (mutex_lock_interruptible(&tsock->lock)) {
 		return -ERESTARTSYS;
 	}
 
@@ -578,7 +572,7 @@ static int send_packet(struct kiocb *iocb, struct socket *sock,
 		res = tipc_send(tsock->p->ref, m->msg_iovlen, m->msg_iov);
 		if (likely(res != -ELINKCONG)) {
 exit:
-			up(&tsock->sem);
+			mutex_unlock(&tsock->lock);
 			return res;
 		}
 		if (m->msg_flags & MSG_DONTWAIT) {
@@ -846,7 +840,7 @@ static int recv_msg(struct kiocb *iocb, struct socket *sock,
 
 	/* Look for a message in receive queue; wait if necessary */
 
-	if (unlikely(down_interruptible(&tsock->sem)))
+	if (unlikely(mutex_lock_interruptible(&tsock->lock)))
 		return -ERESTARTSYS;
 
 restart:
@@ -930,7 +924,7 @@ restart:
 		advance_queue(tsock);
 	}
 exit:
-	up(&tsock->sem);
+	mutex_unlock(&tsock->lock);
 	return res;
 }
 
@@ -981,7 +975,7 @@ static int recv_stream(struct kiocb *iocb, struct socket *sock,
 
 	/* Look for a message in receive queue; wait if necessary */
 
-	if (unlikely(down_interruptible(&tsock->sem)))
+	if (unlikely(mutex_lock_interruptible(&tsock->lock)))
 		return -ERESTARTSYS;
 
 restart:
@@ -1077,7 +1071,7 @@ restart:
 		goto restart;
 
 exit:
-	up(&tsock->sem);
+	mutex_unlock(&tsock->lock);
 	return sz_copied ? sz_copied : res;
 }
 
@@ -1293,7 +1287,7 @@ static int connect(struct socket *sock, struct sockaddr *dest, int destlen,
 	   return res;
    }
 
-   if (down_interruptible(&tsock->sem))
+   if (mutex_lock_interruptible(&tsock->lock))
 	   return -ERESTARTSYS;
 
    /* Wait for destination's 'ACK' response */
@@ -1317,7 +1311,7 @@ static int connect(struct socket *sock, struct sockaddr *dest, int destlen,
 	   sock->state = SS_DISCONNECTING;
    }
 
-   up(&tsock->sem);
+   mutex_unlock(&tsock->lock);
    return res;
 }
 
@@ -1365,7 +1359,7 @@ static int accept(struct socket *sock, struct socket *newsock, int flags)
 		     (flags & O_NONBLOCK)))
 		return -EWOULDBLOCK;
 
-	if (down_interruptible(&tsock->sem))
+	if (mutex_lock_interruptible(&tsock->lock))
 		return -ERESTARTSYS;
 
 	if (wait_event_interruptible(*sock->sk->sk_sleep,
@@ -1375,7 +1369,7 @@ static int accept(struct socket *sock, struct socket *newsock, int flags)
 	}
 	buf = skb_peek(&sock->sk->sk_receive_queue);
 
-	res = tipc_create(sock->sk->sk_net, newsock, 0);
+	res = tipc_create(sock_net(sock->sk), newsock, 0);
 	if (!res) {
 		struct tipc_sock *new_tsock = tipc_sk(newsock->sk);
 		struct tipc_portid id;
@@ -1412,14 +1406,14 @@ static int accept(struct socket *sock, struct socket *newsock, int flags)
 		}
 	}
 exit:
-	up(&tsock->sem);
+	mutex_unlock(&tsock->lock);
 	return res;
 }
 
 /**
  * shutdown - shutdown socket connection
  * @sock: socket structure
- * @how: direction to close (unused; always treated as read + write)
+ * @how: direction to close (must be SHUT_RDWR)
  *
  * Terminates connection (if necessary), then purges socket's receive queue.
  *
@@ -1432,9 +1426,10 @@ static int shutdown(struct socket *sock, int how)
 	struct sk_buff *buf;
 	int res;
 
-	/* Could return -EINVAL for an invalid "how", but why bother? */
+	if (how != SHUT_RDWR)
+		return -EINVAL;
 
-	if (down_interruptible(&tsock->sem))
+	if (mutex_lock_interruptible(&tsock->lock))
 		return -ERESTARTSYS;
 
 	sock_lock(tsock);
@@ -1484,7 +1479,7 @@ restart:
 
 	sock_unlock(tsock);
 
-	up(&tsock->sem);
+	mutex_unlock(&tsock->lock);
 	return res;
 }
 
@@ -1518,7 +1513,7 @@ static int setsockopt(struct socket *sock,
 	if ((res = get_user(value, (u32 __user *)ov)))
 		return res;
 
-	if (down_interruptible(&tsock->sem))
+	if (mutex_lock_interruptible(&tsock->lock))
 		return -ERESTARTSYS;
 
 	switch (opt) {
@@ -1541,7 +1536,7 @@ static int setsockopt(struct socket *sock,
 		res = -EINVAL;
 	}
 
-	up(&tsock->sem);
+	mutex_unlock(&tsock->lock);
 	return res;
 }
 
@@ -1574,7 +1569,7 @@ static int getsockopt(struct socket *sock,
 	if ((res = get_user(len, ol)))
 		return res;
 
-	if (down_interruptible(&tsock->sem))
+	if (mutex_lock_interruptible(&tsock->lock))
 		return -ERESTARTSYS;
 
 	switch (opt) {
@@ -1607,7 +1602,7 @@ static int getsockopt(struct socket *sock,
 		res = put_user(sizeof(value), ol);
 	}
 
-	up(&tsock->sem);
+	mutex_unlock(&tsock->lock);
 	return res;
 }