1 files changed, 71 insertions, 62 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 51be64f163ec..c1f403bed683 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -114,6 +114,7 @@
 #include <linux/mount.h>
 #include <net/checksum.h>
 #include <linux/security.h>
+#include <linux/freezer.h>
 
 struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE];
 EXPORT_SYMBOL_GPL(unix_socket_table);
@@ -382,7 +383,7 @@ static void unix_sock_destructor(struct sock *sk)
 #endif
 }
 
-static int unix_release_sock(struct sock *sk, int embrion)
+static void unix_release_sock(struct sock *sk, int embrion)
 {
 	struct unix_sock *u = unix_sk(sk);
 	struct path path;
@@ -451,8 +452,6 @@ static int unix_release_sock(struct sock *sk, int embrion)
 
 	if (unix_tot_inflight)
 		unix_gc();		/* Garbage collect fds */
-
-	return 0;
 }
 
 static void init_peercred(struct sock *sk)
@@ -699,9 +698,10 @@ static int unix_release(struct socket *sock)
 	if (!sk)
 		return 0;
 
+	unix_release_sock(sk, 0);
 	sock->sk = NULL;
 
-	return unix_release_sock(sk, 0);
+	return 0;
 }
 
 static int unix_autobind(struct socket *sock)
@@ -1246,6 +1246,15 @@ static int unix_socketpair(struct socket *socka, struct socket *sockb)
 	return 0;
 }
 
+static void unix_sock_inherit_flags(const struct socket *old,
+				    struct socket *new)
+{
+	if (test_bit(SOCK_PASSCRED, &old->flags))
+		set_bit(SOCK_PASSCRED, &new->flags);
+	if (test_bit(SOCK_PASSSEC, &old->flags))
+		set_bit(SOCK_PASSSEC, &new->flags);
+}
+
 static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
 {
 	struct sock *sk = sock->sk;
@@ -1280,6 +1289,7 @@ static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
 	/* attach accepted sock to socket */
 	unix_state_lock(tsk);
 	newsock->state = SS_CONNECTED;
+	unix_sock_inherit_flags(sock, newsock);
 	sock_graft(tsk, newsock);
 	unix_state_unlock(tsk);
 	return 0;
@@ -1341,7 +1351,6 @@ static void unix_destruct_scm(struct sk_buff *skb)
 	struct scm_cookie scm;
 	memset(&scm, 0, sizeof(scm));
 	scm.pid  = UNIXCB(skb).pid;
-	scm.cred = UNIXCB(skb).cred;
 	if (UNIXCB(skb).fp)
 		unix_detach_fds(&scm, skb);
 
@@ -1392,8 +1401,8 @@ static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool sen
 	int err = 0;
 
 	UNIXCB(skb).pid  = get_pid(scm->pid);
-	if (scm->cred)
-		UNIXCB(skb).cred = get_cred(scm->cred);
+	UNIXCB(skb).uid = scm->creds.uid;
+	UNIXCB(skb).gid = scm->creds.gid;
 	UNIXCB(skb).fp = NULL;
 	if (scm->fp && send_fds)
 		err = unix_attach_fds(scm, skb);
@@ -1410,13 +1419,13 @@ static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool sen
 static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock,
 			    const struct sock *other)
 {
-	if (UNIXCB(skb).cred)
+	if (UNIXCB(skb).pid)
 		return;
 	if (test_bit(SOCK_PASSCRED, &sock->flags) ||
 	    !other->sk_socket ||
 	    test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) {
 		UNIXCB(skb).pid  = get_pid(task_tgid(current));
-		UNIXCB(skb).cred = get_current_cred();
+		current_uid_gid(&UNIXCB(skb).uid, &UNIXCB(skb).gid);
 	}
 }
 
@@ -1480,7 +1489,8 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
 				 MAX_SKB_FRAGS * PAGE_SIZE);
 
 	skb = sock_alloc_send_pskb(sk, len - data_len, data_len,
-				   msg->msg_flags & MSG_DONTWAIT, &err);
+				   msg->msg_flags & MSG_DONTWAIT, &err,
+				   PAGE_ALLOC_COSTLY_ORDER);
 	if (skb == NULL)
 		goto out;
 
@@ -1597,6 +1607,10 @@ out:
 	return err;
 }
 
+/* We use paged skbs for stream sockets, and limit occupancy to 32768
+ * bytes, and a minimun of a full page.
+ */
+#define UNIX_SKB_FRAGS_SZ (PAGE_SIZE << get_order(32768))
 
 static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
 			       struct msghdr *msg, size_t len)
@@ -1610,6 +1624,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
 	struct scm_cookie tmp_scm;
 	bool fds_sent = false;
 	int max_level;
+	int data_len;
 
 	if (NULL == siocb->scm)
 		siocb->scm = &tmp_scm;
@@ -1636,40 +1651,22 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
 		goto pipe_err;
 
 	while (sent < len) {
-		/*
-		 *	Optimisation for the fact that under 0.01% of X
-		 *	messages typically need breaking up.
-		 */
-
-		size = len-sent;
+		size = len - sent;
 
 		/* Keep two messages in the pipe so it schedules better */
-		if (size > ((sk->sk_sndbuf >> 1) - 64))
-			size = (sk->sk_sndbuf >> 1) - 64;
+		size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64);
 
-		if (size > SKB_MAX_ALLOC)
-			size = SKB_MAX_ALLOC;
+		/* allow fallback to order-0 allocations */
+		size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ);
 
-		/*
-		 *	Grab a buffer
-		 */
-
-		skb = sock_alloc_send_skb(sk, size, msg->msg_flags&MSG_DONTWAIT,
-					  &err);
+		data_len = max_t(int, 0, size - SKB_MAX_HEAD(0));
 
-		if (skb == NULL)
+		skb = sock_alloc_send_pskb(sk, size - data_len, data_len,
+					   msg->msg_flags & MSG_DONTWAIT, &err,
+					   get_order(UNIX_SKB_FRAGS_SZ));
+		if (!skb)
 			goto out_err;
 
-		/*
-		 *	If you pass two values to the sock_alloc_send_skb
-		 *	it tries to grab the large buffer with GFP_NOFS
-		 *	(which can fail easily), and if it fails grab the
-		 *	fallback size buffer which is under a page and will
-		 *	succeed. [Alan]
-		 */
-		size = min_t(int, size, skb_tailroom(skb));
-
-
 		/* Only send the fds in the first buffer */
 		err = unix_scm_to_skb(siocb->scm, skb, !fds_sent);
 		if (err < 0) {
@@ -1679,7 +1676,11 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
 		max_level = err + 1;
 		fds_sent = true;
 
-		err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
+		skb_put(skb, size - data_len);
+		skb->data_len = data_len;
+		skb->len = size;
+		err = skb_copy_datagram_from_iovec(skb, 0, msg->msg_iov,
+						   sent, size);
 		if (err) {
 			kfree_skb(skb);
 			goto out_err;
@@ -1820,7 +1821,7 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock,
 		siocb->scm = &tmp_scm;
 		memset(&tmp_scm, 0, sizeof(tmp_scm));
 	}
-	scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred);
+	scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
 	unix_set_secdata(siocb->scm, skb);
 
 	if (!(flags & MSG_PEEK)) {
@@ -1860,10 +1861,10 @@ out:
 }
 
 /*
- *	Sleep until data has arrive. But check for races..
+ *	Sleep until more data has arrived. But check for races..
  */
-
-static long unix_stream_data_wait(struct sock *sk, long timeo)
+static long unix_stream_data_wait(struct sock *sk, long timeo,
+				  struct sk_buff *last)
 {
 	DEFINE_WAIT(wait);
 
@@ -1872,7 +1873,7 @@ static long unix_stream_data_wait(struct sock *sk, long timeo)
 	for (;;) {
 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 
-		if (!skb_queue_empty(&sk->sk_receive_queue) ||
+		if (skb_peek_tail(&sk->sk_receive_queue) != last ||
 		    sk->sk_err ||
 		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
 		    signal_pending(current) ||
@@ -1881,7 +1882,7 @@ static long unix_stream_data_wait(struct sock *sk, long timeo)
 
 		set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
 		unix_state_unlock(sk);
-		timeo = schedule_timeout(timeo);
+		timeo = freezable_schedule_timeout(timeo);
 		unix_state_lock(sk);
 		clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
 	}
@@ -1891,7 +1892,10 @@ static long unix_stream_data_wait(struct sock *sk, long timeo)
 	return timeo;
 }
 
-
+static unsigned int unix_skb_len(const struct sk_buff *skb)
+{
+	return skb->len - UNIXCB(skb).consumed;
+}
 
 static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
 			       struct msghdr *msg, size_t size,
@@ -1937,14 +1941,12 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
 		goto out;
 	}
 
-	skip = sk_peek_offset(sk, flags);
-
 	do {
 		int chunk;
-		struct sk_buff *skb;
+		struct sk_buff *skb, *last;
 
 		unix_state_lock(sk);
-		skb = skb_peek(&sk->sk_receive_queue);
+		last = skb = skb_peek(&sk->sk_receive_queue);
 again:
 		if (skb == NULL) {
 			unix_sk(sk)->recursion_level = 0;
@@ -1967,7 +1969,7 @@ again:
 				break;
 			mutex_unlock(&u->readlock);
 
-			timeo = unix_stream_data_wait(sk, timeo);
+			timeo = unix_stream_data_wait(sk, timeo, last);
 
 			if (signal_pending(current)
 			    ||  mutex_lock_interruptible(&u->readlock)) {
@@ -1981,10 +1983,13 @@ again:
 			break;
 		}
 
-		if (skip >= skb->len) {
-			skip -= skb->len;
+		skip = sk_peek_offset(sk, flags);
+		while (skip >= unix_skb_len(skb)) {
+			skip -= unix_skb_len(skb);
+			last = skb;
 			skb = skb_peek_next(skb, &sk->sk_receive_queue);
-			goto again;
+			if (!skb)
+				goto again;
 		}
 
 		unix_state_unlock(sk);
@@ -1992,11 +1997,12 @@ again:
 		if (check_creds) {
 			/* Never glue messages from different writers */
 			if ((UNIXCB(skb).pid  != siocb->scm->pid) ||
-			    (UNIXCB(skb).cred != siocb->scm->cred))
+			    !uid_eq(UNIXCB(skb).uid, siocb->scm->creds.uid) ||
+			    !gid_eq(UNIXCB(skb).gid, siocb->scm->creds.gid))
 				break;
-		} else {
+		} else if (test_bit(SOCK_PASSCRED, &sock->flags)) {
 			/* Copy credentials */
-			scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).cred);
+			scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
 			check_creds = 1;
 		}
 
@@ -2006,8 +2012,9 @@ again:
 			sunaddr = NULL;
 		}
 
-		chunk = min_t(unsigned int, skb->len - skip, size);
-		if (memcpy_toiovec(msg->msg_iov, skb->data + skip, chunk)) {
+		chunk = min_t(unsigned int, unix_skb_len(skb) - skip, size);
+		if (skb_copy_datagram_iovec(skb, UNIXCB(skb).consumed + skip,
+					    msg->msg_iov, chunk)) {
 			if (copied == 0)
 				copied = -EFAULT;
 			break;
@@ -2017,14 +2024,14 @@ again:
 
 		/* Mark read part of skb as used */
 		if (!(flags & MSG_PEEK)) {
-			skb_pull(skb, chunk);
+			UNIXCB(skb).consumed += chunk;
 
 			sk_peek_offset_bwd(sk, chunk);
 
 			if (UNIXCB(skb).fp)
 				unix_detach_fds(siocb->scm, skb);
 
-			if (skb->len)
+			if (unix_skb_len(skb))
 				break;
 
 			skb_unlink(skb, &sk->sk_receive_queue);
@@ -2108,7 +2115,7 @@ long unix_inq_len(struct sock *sk)
 	if (sk->sk_type == SOCK_STREAM ||
 	    sk->sk_type == SOCK_SEQPACKET) {
 		skb_queue_walk(&sk->sk_receive_queue, skb)
-			amount += skb->len;
+			amount += unix_skb_len(skb);
 	} else {
 		skb = skb_peek(&sk->sk_receive_queue);
 		if (skb)
@@ -2197,7 +2204,9 @@ 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)