Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

1 files changed, 69 insertions, 72 deletions

diff --git a/kernel/net/unix/af_unix.c b/kernel/net/unix/af_unix.c
index 898a53a56..b2e934ff2 100644
--- a/kernel/net/unix/af_unix.c
+++ b/kernel/net/unix/af_unix.c
@@ -315,7 +315,7 @@ static struct sock *unix_find_socket_byinode(struct inode *i)
 		    &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
 		struct dentry *dentry = unix_sk(s)->path.dentry;
 
-		if (dentry && d_backing_inode(dentry) == i) {
+		if (dentry && d_real_inode(dentry) == i) {
 			sock_hold(s);
 			goto found;
 		}
@@ -661,11 +661,11 @@ static int unix_set_peek_off(struct sock *sk, int val)
 {
 	struct unix_sock *u = unix_sk(sk);
 
-	if (mutex_lock_interruptible(&u->readlock))
+	if (mutex_lock_interruptible(&u->iolock))
 		return -EINTR;
 
 	sk->sk_peek_off = val;
-	mutex_unlock(&u->readlock);
+	mutex_unlock(&u->iolock);
 
 	return 0;
 }
@@ -778,7 +778,8 @@ static struct sock *unix_create1(struct net *net, struct socket *sock, int kern)
 	spin_lock_init(&u->lock);
 	atomic_long_set(&u->inflight, 0);
 	INIT_LIST_HEAD(&u->link);
-	mutex_init(&u->readlock); /* single task reading lock */
+	mutex_init(&u->iolock); /* single task reading lock */
+	mutex_init(&u->bindlock); /* single task binding lock */
 	init_waitqueue_head(&u->peer_wait);
 	init_waitqueue_func_entry(&u->peer_wake, unix_dgram_peer_wake_relay);
 	unix_insert_socket(unix_sockets_unbound(sk), sk);
@@ -847,7 +848,7 @@ static int unix_autobind(struct socket *sock)
 	int err;
 	unsigned int retries = 0;
 
-	err = mutex_lock_interruptible(&u->readlock);
+	err = mutex_lock_interruptible(&u->bindlock);
 	if (err)
 		return err;
 
@@ -894,7 +895,7 @@ retry:
 	spin_unlock(&unix_table_lock);
 	err = 0;
 
-out:	mutex_unlock(&u->readlock);
+out:	mutex_unlock(&u->bindlock);
 	return err;
 }
 
@@ -911,7 +912,7 @@ static struct sock *unix_find_other(struct net *net,
 		err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
 		if (err)
 			goto fail;
-		inode = d_backing_inode(path.dentry);
+		inode = d_real_inode(path.dentry);
 		err = inode_permission(inode, MAY_WRITE);
 		if (err)
 			goto put_fail;
@@ -953,20 +954,32 @@ fail:
 	return NULL;
 }
 
-static int unix_mknod(struct dentry *dentry, struct path *path, umode_t mode,
-		      struct path *res)
+static int unix_mknod(const char *sun_path, umode_t mode, struct path *res)
 {
-	int err;
+	struct dentry *dentry;
+	struct path path;
+	int err = 0;
+	/*
+	 * Get the parent directory, calculate the hash for last
+	 * component.
+	 */
+	dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0);
+	err = PTR_ERR(dentry);
+	if (IS_ERR(dentry))
+		return err;
 
-	err = security_path_mknod(path, dentry, mode, 0);
+	/*
+	 * All right, let's create it.
+	 */
+	err = security_path_mknod(&path, dentry, mode, 0);
 	if (!err) {
-		err = vfs_mknod(d_inode(path->dentry), dentry, mode, 0);
+		err = vfs_mknod(d_inode(path.dentry), dentry, mode, 0);
 		if (!err) {
-			res->mnt = mntget(path->mnt);
+			res->mnt = mntget(path.mnt);
 			res->dentry = dget(dentry);
 		}
 	}
-
+	done_path_create(&path, dentry);
 	return err;
 }
 
@@ -977,12 +990,11 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	struct unix_sock *u = unix_sk(sk);
 	struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
 	char *sun_path = sunaddr->sun_path;
-	int err, name_err;
+	int err;
 	unsigned int hash;
 	struct unix_address *addr;
 	struct hlist_head *list;
-	struct path path;
-	struct dentry *dentry;
+	struct path path = { NULL, NULL };
 
 	err = -EINVAL;
 	if (sunaddr->sun_family != AF_UNIX)
@@ -998,34 +1010,25 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		goto out;
 	addr_len = err;
 
-	name_err = 0;
-	dentry = NULL;
 	if (sun_path[0]) {
-		/* Get the parent directory, calculate the hash for last
-		 * component.
-		 */
-		dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0);
-
-		if (IS_ERR(dentry)) {
-			/* delay report until after 'already bound' check */
-			name_err = PTR_ERR(dentry);
-			dentry = NULL;
+		umode_t mode = S_IFSOCK |
+		       (SOCK_INODE(sock)->i_mode & ~current_umask());
+		err = unix_mknod(sun_path, mode, &path);
+		if (err) {
+			if (err == -EEXIST)
+				err = -EADDRINUSE;
+			goto out;
 		}
 	}
 
-	err = mutex_lock_interruptible(&u->readlock);
+	err = mutex_lock_interruptible(&u->bindlock);
 	if (err)
-		goto out_path;
+		goto out_put;
 
 	err = -EINVAL;
 	if (u->addr)
 		goto out_up;
 
-	if (name_err) {
-		err = name_err == -EEXIST ? -EADDRINUSE : name_err;
-		goto out_up;
-	}
-
 	err = -ENOMEM;
 	addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
 	if (!addr)
@@ -1036,21 +1039,11 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	addr->hash = hash ^ sk->sk_type;
 	atomic_set(&addr->refcnt, 1);
 
-	if (dentry) {
-		struct path u_path;
-		umode_t mode = S_IFSOCK |
-		       (SOCK_INODE(sock)->i_mode & ~current_umask());
-		err = unix_mknod(dentry, &path, mode, &u_path);
-		if (err) {
-			if (err == -EEXIST)
-				err = -EADDRINUSE;
-			unix_release_addr(addr);
-			goto out_up;
-		}
+	if (sun_path[0]) {
 		addr->hash = UNIX_HASH_SIZE;
-		hash = d_backing_inode(dentry)->i_ino & (UNIX_HASH_SIZE - 1);
+		hash = d_real_inode(path.dentry)->i_ino & (UNIX_HASH_SIZE - 1);
 		spin_lock(&unix_table_lock);
-		u->path = u_path;
+		u->path = path;
 		list = &unix_socket_table[hash];
 	} else {
 		spin_lock(&unix_table_lock);
@@ -1072,11 +1065,10 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 out_unlock:
 	spin_unlock(&unix_table_lock);
 out_up:
-	mutex_unlock(&u->readlock);
-out_path:
-	if (dentry)
-		done_path_create(&path, dentry);
-
+	mutex_unlock(&u->bindlock);
+out_put:
+	if (err)
+		path_put(&path);
 out:
 	return err;
 }
@@ -1971,17 +1963,17 @@ static ssize_t unix_stream_sendpage(struct socket *socket, struct page *page,
 	if (false) {
 alloc_skb:
 		unix_state_unlock(other);
-		mutex_unlock(&unix_sk(other)->readlock);
+		mutex_unlock(&unix_sk(other)->iolock);
 		newskb = sock_alloc_send_pskb(sk, 0, 0, flags & MSG_DONTWAIT,
 					      &err, 0);
 		if (!newskb)
 			goto err;
 	}
 
-	/* we must acquire readlock as we modify already present
+	/* we must acquire iolock as we modify already present
 	 * skbs in the sk_receive_queue and mess with skb->len
 	 */
-	err = mutex_lock_interruptible(&unix_sk(other)->readlock);
+	err = mutex_lock_interruptible(&unix_sk(other)->iolock);
 	if (err) {
 		err = flags & MSG_DONTWAIT ? -EAGAIN : -ERESTARTSYS;
 		goto err;
@@ -2048,7 +2040,7 @@ alloc_skb:
 	}
 
 	unix_state_unlock(other);
-	mutex_unlock(&unix_sk(other)->readlock);
+	mutex_unlock(&unix_sk(other)->iolock);
 
 	other->sk_data_ready(other);
 	scm_destroy(&scm);
@@ -2057,7 +2049,7 @@ alloc_skb:
 err_state_unlock:
 	unix_state_unlock(other);
 err_unlock:
-	mutex_unlock(&unix_sk(other)->readlock);
+	mutex_unlock(&unix_sk(other)->iolock);
 err:
 	kfree_skb(newskb);
 	if (send_sigpipe && !(flags & MSG_NOSIGNAL))
@@ -2122,7 +2114,7 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
 	if (flags&MSG_OOB)
 		goto out;
 
-	err = mutex_lock_interruptible(&u->readlock);
+	err = mutex_lock_interruptible(&u->iolock);
 	if (unlikely(err)) {
 		/* recvmsg() in non blocking mode is supposed to return -EAGAIN
 		 * sk_rcvtimeo is not honored by mutex_lock_interruptible()
@@ -2198,7 +2190,7 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
 out_free:
 	skb_free_datagram(sk, skb);
 out_unlock:
-	mutex_unlock(&u->readlock);
+	mutex_unlock(&u->iolock);
 out:
 	return err;
 }
@@ -2207,7 +2199,8 @@ out:
  *	Sleep until more data has arrived. But check for races..
  */
 static long unix_stream_data_wait(struct sock *sk, long timeo,
-				  struct sk_buff *last, unsigned int last_len)
+				  struct sk_buff *last, unsigned int last_len,
+				  bool freezable)
 {
 	struct sk_buff *tail;
 	DEFINE_WAIT(wait);
@@ -2228,7 +2221,10 @@ static long unix_stream_data_wait(struct sock *sk, long timeo,
 
 		sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 		unix_state_unlock(sk);
-		timeo = freezable_schedule_timeout(timeo);
+		if (freezable)
+			timeo = freezable_schedule_timeout(timeo);
+		else
+			timeo = schedule_timeout(timeo);
 		unix_state_lock(sk);
 
 		if (sock_flag(sk, SOCK_DEAD))
@@ -2258,7 +2254,8 @@ struct unix_stream_read_state {
 	unsigned int splice_flags;
 };
 
-static int unix_stream_read_generic(struct unix_stream_read_state *state)
+static int unix_stream_read_generic(struct unix_stream_read_state *state,
+				    bool freezable)
 {
 	struct scm_cookie scm;
 	struct socket *sock = state->socket;
@@ -2293,7 +2290,7 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state)
 	/* Lock the socket to prevent queue disordering
 	 * while sleeps in memcpy_tomsg
 	 */
-	mutex_lock(&u->readlock);
+	mutex_lock(&u->iolock);
 
 	if (flags & MSG_PEEK)
 		skip = sk_peek_offset(sk, flags);
@@ -2334,10 +2331,10 @@ again:
 				break;
 			}
 
-			mutex_unlock(&u->readlock);
+			mutex_unlock(&u->iolock);
 
 			timeo = unix_stream_data_wait(sk, timeo, last,
-						      last_len);
+						      last_len, freezable);
 
 			if (signal_pending(current)) {
 				err = sock_intr_errno(timeo);
@@ -2345,7 +2342,7 @@ again:
 				goto out;
 			}
 
-			mutex_lock(&u->readlock);
+			mutex_lock(&u->iolock);
 			continue;
 unlock:
 			unix_state_unlock(sk);
@@ -2448,7 +2445,7 @@ unlock:
 		}
 	} while (size);
 
-	mutex_unlock(&u->readlock);
+	mutex_unlock(&u->iolock);
 	if (state->msg)
 		scm_recv(sock, state->msg, &scm, flags);
 	else
@@ -2479,7 +2476,7 @@ static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg,
 		.flags = flags
 	};
 
-	return unix_stream_read_generic(&state);
+	return unix_stream_read_generic(&state, true);
 }
 
 static ssize_t skb_unix_socket_splice(struct sock *sk,
@@ -2489,9 +2486,9 @@ static ssize_t skb_unix_socket_splice(struct sock *sk,
 	int ret;
 	struct unix_sock *u = unix_sk(sk);
 
-	mutex_unlock(&u->readlock);
+	mutex_unlock(&u->iolock);
 	ret = splice_to_pipe(pipe, spd);
-	mutex_lock(&u->readlock);
+	mutex_lock(&u->iolock);
 
 	return ret;
 }
@@ -2525,7 +2522,7 @@ static ssize_t unix_stream_splice_read(struct socket *sock,  loff_t *ppos,
 	    flags & SPLICE_F_NONBLOCK)
 		state.flags = MSG_DONTWAIT;
 
-	return unix_stream_read_generic(&state);
+	return unix_stream_read_generic(&state, false);
 }
 
 static int unix_shutdown(struct socket *sock, int mode)