Merge branch 'disintegrate-asm-generic' of git://git.infradead.org/users/dhowells/linux-headers into asm-generic

Patches from David Howells <dhowells@redhat.com>:

This is to complete part of the UAPI disintegration for which the
preparatory patches were pulled recently.

Note that there are some fixup patches which are at the base of the
branch aimed at you, plus all arches get the asm-generic branch merged in too.

* 'disintegrate-asm-generic' of git://git.infradead.org/users/dhowells/linux-headers:
  UAPI: (Scripted) Disintegrate include/asm-generic
  UAPI: Fix conditional header installation handling (notably kvm_para.h on m68k)
  c6x: remove c6x signal.h
  UAPI: Split compound conditionals containing __KERNEL__ in Arm64
  UAPI: Fix the guards on various asm/unistd.h files

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 266 insertions, 154 deletions

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index b425c79675a..2ea176b2280 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -181,10 +181,13 @@ struct tty_struct *alloc_tty_struct(void)
 
 void free_tty_struct(struct tty_struct *tty)
 {
+	if (!tty)
+		return;
 	if (tty->dev)
 		put_device(tty->dev);
 	kfree(tty->write_buf);
 	tty_buffer_free_all(tty);
+	tty->magic = 0xDEADDEAD;
 	kfree(tty);
 }
 
@@ -573,7 +576,7 @@ void __tty_hangup(struct tty_struct *tty)
 	}
 	spin_unlock(&redirect_lock);
 
-	tty_lock();
+	tty_lock(tty);
 
 	/* some functions below drop BTM, so we need this bit */
 	set_bit(TTY_HUPPING, &tty->flags);
@@ -666,7 +669,7 @@ void __tty_hangup(struct tty_struct *tty)
 	clear_bit(TTY_HUPPING, &tty->flags);
 	tty_ldisc_enable(tty);
 
-	tty_unlock();
+	tty_unlock(tty);
 
 	if (f)
 		fput(f);
@@ -1103,12 +1106,12 @@ void tty_write_message(struct tty_struct *tty, char *msg)
 {
 	if (tty) {
 		mutex_lock(&tty->atomic_write_lock);
-		tty_lock();
+		tty_lock(tty);
 		if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) {
-			tty_unlock();
+			tty_unlock(tty);
 			tty->ops->write(tty, msg, strlen(msg));
 		} else
-			tty_unlock();
+			tty_unlock(tty);
 		tty_write_unlock(tty);
 	}
 	return;
@@ -1163,10 +1166,8 @@ ssize_t redirected_tty_write(struct file *file, const char __user *buf,
 	struct file *p = NULL;
 
 	spin_lock(&redirect_lock);
-	if (redirect) {
-		get_file(redirect);
-		p = redirect;
-	}
+	if (redirect)
+		p = get_file(redirect);
 	spin_unlock(&redirect_lock);
 
 	if (p) {
@@ -1213,7 +1214,10 @@ static void pty_line_name(struct tty_driver *driver, int index, char *p)
  */
 static void tty_line_name(struct tty_driver *driver, int index, char *p)
 {
-	sprintf(p, "%s%d", driver->name, index + driver->name_base);
+	if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE)
+		strcpy(p, driver->name);
+	else
+		sprintf(p, "%s%d", driver->name, index + driver->name_base);
 }
 
 /**
@@ -1249,21 +1253,19 @@ int tty_init_termios(struct tty_struct *tty)
 	struct ktermios *tp;
 	int idx = tty->index;
 
-	tp = tty->driver->termios[idx];
-	if (tp == NULL) {
-		tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
-		if (tp == NULL)
-			return -ENOMEM;
-		memcpy(tp, &tty->driver->init_termios,
-						sizeof(struct ktermios));
-		tty->driver->termios[idx] = tp;
+	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
+		tty->termios = tty->driver->init_termios;
+	else {
+		/* Check for lazy saved data */
+		tp = tty->driver->termios[idx];
+		if (tp != NULL)
+			tty->termios = *tp;
+		else
+			tty->termios = tty->driver->init_termios;
 	}
-	tty->termios = tp;
-	tty->termios_locked = tp + 1;
-
 	/* Compatibility until drivers always set this */
-	tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
-	tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
+	tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios);
+	tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(tty_init_termios);
@@ -1403,10 +1405,18 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx)
 	}
 	initialize_tty_struct(tty, driver, idx);
 
+	tty_lock(tty);
 	retval = tty_driver_install_tty(driver, tty);
 	if (retval < 0)
 		goto err_deinit_tty;
 
+	if (!tty->port)
+		tty->port = driver->ports[idx];
+
+	WARN_RATELIMIT(!tty->port,
+			"%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n",
+			__func__, tty->driver->name);
+
 	/*
 	 * Structures all installed ... call the ldisc open routines.
 	 * If we fail here just call release_tty to clean up.  No need
@@ -1415,9 +1425,11 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx)
 	retval = tty_ldisc_setup(tty, tty->link);
 	if (retval)
 		goto err_release_tty;
+	/* Return the tty locked so that it cannot vanish under the caller */
 	return tty;
 
 err_deinit_tty:
+	tty_unlock(tty);
 	deinitialize_tty_struct(tty);
 	free_tty_struct(tty);
 err_module_put:
@@ -1426,6 +1438,7 @@ err_module_put:
 
 	/* call the tty release_tty routine to clean out this slot */
 err_release_tty:
+	tty_unlock(tty);
 	printk_ratelimited(KERN_INFO "tty_init_dev: ldisc open failed, "
 				 "clearing slot %d\n", idx);
 	release_tty(tty, idx);
@@ -1436,22 +1449,25 @@ void tty_free_termios(struct tty_struct *tty)
 {
 	struct ktermios *tp;
 	int idx = tty->index;
-	/* Kill this flag and push into drivers for locking etc */
-	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
-		/* FIXME: Locking on ->termios array */
-		tp = tty->termios;
-		tty->driver->termios[idx] = NULL;
-		kfree(tp);
+
+	/* If the port is going to reset then it has no termios to save */
+	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
+		return;
+
+	/* Stash the termios data */
+	tp = tty->driver->termios[idx];
+	if (tp == NULL) {
+		tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
+		if (tp == NULL) {
+			pr_warn("tty: no memory to save termios state.\n");
+			return;
+		}
+		tty->driver->termios[idx] = tp;
 	}
+	*tp = tty->termios;
 }
 EXPORT_SYMBOL(tty_free_termios);
 
-void tty_shutdown(struct tty_struct *tty)
-{
-	tty_driver_remove_tty(tty->driver, tty);
-	tty_free_termios(tty);
-}
-EXPORT_SYMBOL(tty_shutdown);
 
 /**
  *	release_one_tty		-	release tty structure memory
@@ -1462,7 +1478,6 @@ EXPORT_SYMBOL(tty_shutdown);
  *	in use. It also gets called when setup of a device fails.
  *
  *	Locking:
- *		tty_mutex - sometimes only
  *		takes the file list lock internally when working on the list
  *	of ttys that the driver keeps.
  *
@@ -1495,11 +1510,6 @@ static void queue_release_one_tty(struct kref *kref)
 {
 	struct tty_struct *tty = container_of(kref, struct tty_struct, kref);
 
-	if (tty->ops->shutdown)
-		tty->ops->shutdown(tty);
-	else
-		tty_shutdown(tty);
-
 	/* The hangup queue is now free so we can reuse it rather than
 	   waste a chunk of memory for each port */
 	INIT_WORK(&tty->hangup_work, release_one_tty);
@@ -1528,16 +1538,20 @@ EXPORT_SYMBOL(tty_kref_put);
  *	and decrement the refcount of the backing module.
  *
  *	Locking:
- *		tty_mutex - sometimes only
+ *		tty_mutex
  *		takes the file list lock internally when working on the list
  *	of ttys that the driver keeps.
- *		FIXME: should we require tty_mutex is held here ??
  *
  */
 static void release_tty(struct tty_struct *tty, int idx)
 {
 	/* This should always be true but check for the moment */
 	WARN_ON(tty->index != idx);
+	WARN_ON(!mutex_is_locked(&tty_mutex));
+	if (tty->ops->shutdown)
+		tty->ops->shutdown(tty);
+	tty_free_termios(tty);
+	tty_driver_remove_tty(tty->driver, tty);
 
 	if (tty->link)
 		tty_kref_put(tty->link);
@@ -1572,22 +1586,12 @@ static int tty_release_checks(struct tty_struct *tty, struct tty_struct *o_tty,
 				__func__, idx, tty->name);
 		return -1;
 	}
-	if (tty->termios != tty->driver->termios[idx]) {
-		printk(KERN_DEBUG "%s: driver.termios[%d] not termios for (%s)\n",
-				__func__, idx, tty->name);
-		return -1;
-	}
 	if (tty->driver->other) {
 		if (o_tty != tty->driver->other->ttys[idx]) {
 			printk(KERN_DEBUG "%s: other->table[%d] not o_tty for (%s)\n",
 					__func__, idx, tty->name);
 			return -1;
 		}
-		if (o_tty->termios != tty->driver->other->termios[idx]) {
-			printk(KERN_DEBUG "%s: other->termios[%d] not o_termios for (%s)\n",
-					__func__, idx, tty->name);
-			return -1;
-		}
 		if (o_tty->link != tty) {
 			printk(KERN_DEBUG "%s: bad pty pointers\n", __func__);
 			return -1;
@@ -1628,7 +1632,7 @@ int tty_release(struct inode *inode, struct file *filp)
 	if (tty_paranoia_check(tty, inode, __func__))
 		return 0;
 
-	tty_lock();
+	tty_lock(tty);
 	check_tty_count(tty, __func__);
 
 	__tty_fasync(-1, filp, 0);
@@ -1637,10 +1641,11 @@ int tty_release(struct inode *inode, struct file *filp)
 	pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
 		      tty->driver->subtype == PTY_TYPE_MASTER);
 	devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0;
+	/* Review: parallel close */
 	o_tty = tty->link;
 
 	if (tty_release_checks(tty, o_tty, idx)) {
-		tty_unlock();
+		tty_unlock(tty);
 		return 0;
 	}
 
@@ -1652,7 +1657,7 @@ int tty_release(struct inode *inode, struct file *filp)
 	if (tty->ops->close)
 		tty->ops->close(tty, filp);
 
-	tty_unlock();
+	tty_unlock(tty);
 	/*
 	 * Sanity check: if tty->count is going to zero, there shouldn't be
 	 * any waiters on tty->read_wait or tty->write_wait.  We test the
@@ -1675,7 +1680,7 @@ int tty_release(struct inode *inode, struct file *filp)
 		   opens on /dev/tty */
 
 		mutex_lock(&tty_mutex);
-		tty_lock();
+		tty_lock_pair(tty, o_tty);
 		tty_closing = tty->count <= 1;
 		o_tty_closing = o_tty &&
 			(o_tty->count <= (pty_master ? 1 : 0));
@@ -1706,7 +1711,7 @@ int tty_release(struct inode *inode, struct file *filp)
 
 		printk(KERN_WARNING "%s: %s: read/write wait queue active!\n",
 				__func__, tty_name(tty, buf));
-		tty_unlock();
+		tty_unlock_pair(tty, o_tty);
 		mutex_unlock(&tty_mutex);
 		schedule();
 	}
@@ -1715,6 +1720,9 @@ int tty_release(struct inode *inode, struct file *filp)
 	 * The closing flags are now consistent with the open counts on
 	 * both sides, and we've completed the last operation that could
 	 * block, so it's safe to proceed with closing.
+	 *
+	 * We must *not* drop the tty_mutex until we ensure that a further
+	 * entry into tty_open can not pick up this tty.
 	 */
 	if (pty_master) {
 		if (--o_tty->count < 0) {
@@ -1766,12 +1774,13 @@ int tty_release(struct inode *inode, struct file *filp)
 	}
 
 	mutex_unlock(&tty_mutex);
+	tty_unlock_pair(tty, o_tty);
+	/* At this point the TTY_CLOSING flag should ensure a dead tty
+	   cannot be re-opened by a racing opener */
 
 	/* check whether both sides are closing ... */
-	if (!tty_closing || (o_tty && !o_tty_closing)) {
-		tty_unlock();
+	if (!tty_closing || (o_tty && !o_tty_closing))
 		return 0;
-	}
 
 #ifdef TTY_DEBUG_HANGUP
 	printk(KERN_DEBUG "%s: freeing tty structure...\n", __func__);
@@ -1782,14 +1791,17 @@ int tty_release(struct inode *inode, struct file *filp)
 	tty_ldisc_release(tty, o_tty);
 	/*
 	 * The release_tty function takes care of the details of clearing
-	 * the slots and preserving the termios structure.
+	 * the slots and preserving the termios structure. The tty_unlock_pair
+	 * should be safe as we keep a kref while the tty is locked (so the
+	 * unlock never unlocks a freed tty).
 	 */
+	mutex_lock(&tty_mutex);
 	release_tty(tty, idx);
+	mutex_unlock(&tty_mutex);
 
 	/* Make this pty number available for reallocation */
 	if (devpts)
 		devpts_kill_index(inode, idx);
-	tty_unlock();
 	return 0;
 }
 
@@ -1893,6 +1905,9 @@ static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp,
  *	Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev.
  *		 tty->count should protect the rest.
  *		 ->siglock protects ->signal/->sighand
+ *
+ *	Note: the tty_unlock/lock cases without a ref are only safe due to
+ *	tty_mutex
  */
 
 static int tty_open(struct inode *inode, struct file *filp)
@@ -1916,8 +1931,7 @@ retry_open:
 	retval = 0;
 
 	mutex_lock(&tty_mutex);
-	tty_lock();
-
+	/* This is protected by the tty_mutex */
 	tty = tty_open_current_tty(device, filp);
 	if (IS_ERR(tty)) {
 		retval = PTR_ERR(tty);
@@ -1938,17 +1952,19 @@ retry_open:
 	}
 
 	if (tty) {
+		tty_lock(tty);
 		retval = tty_reopen(tty);
-		if (retval)
+		if (retval < 0) {
+			tty_unlock(tty);
 			tty = ERR_PTR(retval);
-	} else
+		}
+	} else	/* Returns with the tty_lock held for now */
 		tty = tty_init_dev(driver, index);
 
 	mutex_unlock(&tty_mutex);
 	if (driver)
 		tty_driver_kref_put(driver);
 	if (IS_ERR(tty)) {
-		tty_unlock();
 		retval = PTR_ERR(tty);
 		goto err_file;
 	}
@@ -1977,7 +1993,7 @@ retry_open:
 		printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__,
 				retval, tty->name);
 #endif
-		tty_unlock(); /* need to call tty_release without BTM */
+		tty_unlock(tty); /* need to call tty_release without BTM */
 		tty_release(inode, filp);
 		if (retval != -ERESTARTSYS)
 			return retval;
@@ -1989,17 +2005,15 @@ retry_open:
 		/*
 		 * Need to reset f_op in case a hangup happened.
 		 */
-		tty_lock();
 		if (filp->f_op == &hung_up_tty_fops)
 			filp->f_op = &tty_fops;
-		tty_unlock();
 		goto retry_open;
 	}
-	tty_unlock();
+	tty_unlock(tty);
 
 
 	mutex_lock(&tty_mutex);
-	tty_lock();
+	tty_lock(tty);
 	spin_lock_irq(&current->sighand->siglock);
 	if (!noctty &&
 	    current->signal->leader &&
@@ -2007,11 +2021,10 @@ retry_open:
 	    tty->session == NULL)
 		__proc_set_tty(current, tty);
 	spin_unlock_irq(&current->sighand->siglock);
-	tty_unlock();
+	tty_unlock(tty);
 	mutex_unlock(&tty_mutex);
 	return 0;
 err_unlock:
-	tty_unlock();
 	mutex_unlock(&tty_mutex);
 	/* after locks to avoid deadlock */
 	if (!IS_ERR_OR_NULL(driver))
@@ -2094,10 +2107,13 @@ out:
 
 static int tty_fasync(int fd, struct file *filp, int on)
 {
+	struct tty_struct *tty = file_tty(filp);
 	int retval;
-	tty_lock();
+
+	tty_lock(tty);
 	retval = __tty_fasync(fd, filp, on);
-	tty_unlock();
+	tty_unlock(tty);
+
 	return retval;
 }
 
@@ -2246,8 +2262,7 @@ static int tioccons(struct file *file)
 		spin_unlock(&redirect_lock);
 		return -EBUSY;
 	}
-	get_file(file);
-	redirect = file;
+	redirect = get_file(file);
 	spin_unlock(&redirect_lock);
 	return 0;
 }
@@ -2756,7 +2771,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	if (ld->ops->ioctl) {
 		retval = ld->ops->ioctl(tty, file, cmd, arg);
 		if (retval == -ENOIOCTLCMD)
-			retval = -EINVAL;
+			retval = -ENOTTY;
 	}
 	tty_ldisc_deref(ld);
 	return retval;
@@ -2791,6 +2806,13 @@ static long tty_compat_ioctl(struct file *file, unsigned int cmd,
 }
 #endif
 
+static int this_tty(const void *t, struct file *file, unsigned fd)
+{
+	if (likely(file->f_op->read != tty_read))
+		return 0;
+	return file_tty(file) != t ? 0 : fd + 1;
+}
+	
 /*
  * This implements the "Secure Attention Key" ---  the idea is to
  * prevent trojan horses by killing all processes associated with this
@@ -2818,8 +2840,6 @@ void __do_SAK(struct tty_struct *tty)
 	struct task_struct *g, *p;
 	struct pid *session;
 	int		i;
-	struct file	*filp;
-	struct fdtable *fdt;
 
 	if (!tty)
 		return;
@@ -2849,27 +2869,12 @@ void __do_SAK(struct tty_struct *tty)
 			continue;
 		}
 		task_lock(p);
-		if (p->files) {
-			/*
-			 * We don't take a ref to the file, so we must
-			 * hold ->file_lock instead.
-			 */
-			spin_lock(&p->files->file_lock);
-			fdt = files_fdtable(p->files);
-			for (i = 0; i < fdt->max_fds; i++) {
-				filp = fcheck_files(p->files, i);
-				if (!filp)
-					continue;
-				if (filp->f_op->read == tty_read &&
-				    file_tty(filp) == tty) {
-					printk(KERN_NOTICE "SAK: killed process %d"
-					    " (%s): fd#%d opened to the tty\n",
-					    task_pid_nr(p), p->comm, i);
-					force_sig(SIGKILL, p);
-					break;
-				}
-			}
-			spin_unlock(&p->files->file_lock);
+		i = iterate_fd(p->files, 0, this_tty, tty);
+		if (i != 0) {
+			printk(KERN_NOTICE "SAK: killed process %d"
+			    " (%s): fd#%d opened to the tty\n",
+				    task_pid_nr(p), p->comm, i - 1);
+			force_sig(SIGKILL, p);
 		}
 		task_unlock(p);
 	} while_each_thread(g, p);
@@ -2934,6 +2939,7 @@ void initialize_tty_struct(struct tty_struct *tty,
 	tty->pgrp = NULL;
 	tty->overrun_time = jiffies;
 	tty_buffer_init(tty);
+	mutex_init(&tty->legacy_mutex);
 	mutex_init(&tty->termios_mutex);
 	mutex_init(&tty->ldisc_mutex);
 	init_waitqueue_head(&tty->write_wait);
@@ -2991,6 +2997,15 @@ EXPORT_SYMBOL_GPL(tty_put_char);
 
 struct class *tty_class;
 
+static int tty_cdev_add(struct tty_driver *driver, dev_t dev,
+		unsigned int index, unsigned int count)
+{
+	/* init here, since reused cdevs cause crashes */
+	cdev_init(&driver->cdevs[index], &tty_fops);
+	driver->cdevs[index].owner = driver->owner;
+	return cdev_add(&driver->cdevs[index], dev, count);
+}
+
 /**
  *	tty_register_device - register a tty device
  *	@driver: the tty driver that describes the tty device
@@ -3013,8 +3028,46 @@ struct class *tty_class;
 struct device *tty_register_device(struct tty_driver *driver, unsigned index,
 				   struct device *device)
 {
+	return tty_register_device_attr(driver, index, device, NULL, NULL);
+}
+EXPORT_SYMBOL(tty_register_device);
+
+static void tty_device_create_release(struct device *dev)
+{
+	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
+	kfree(dev);
+}
+
+/**
+ *	tty_register_device_attr - register a tty device
+ *	@driver: the tty driver that describes the tty device
+ *	@index: the index in the tty driver for this tty device
+ *	@device: a struct device that is associated with this tty device.
+ *		This field is optional, if there is no known struct device
+ *		for this tty device it can be set to NULL safely.
+ *	@drvdata: Driver data to be set to device.
+ *	@attr_grp: Attribute group to be set on device.
+ *
+ *	Returns a pointer to the struct device for this tty device
+ *	(or ERR_PTR(-EFOO) on error).
+ *
+ *	This call is required to be made to register an individual tty device
+ *	if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set.  If
+ *	that bit is not set, this function should not be called by a tty
+ *	driver.
+ *
+ *	Locking: ??
+ */
+struct device *tty_register_device_attr(struct tty_driver *driver,
+				   unsigned index, struct device *device,
+				   void *drvdata,
+				   const struct attribute_group **attr_grp)
+{
 	char name[64];
-	dev_t dev = MKDEV(driver->major, driver->minor_start) + index;
+	dev_t devt = MKDEV(driver->major, driver->minor_start) + index;
+	struct device *dev = NULL;
+	int retval = -ENODEV;
+	bool cdev = false;
 
 	if (index >= driver->num) {
 		printk(KERN_ERR "Attempt to register invalid tty line number "
@@ -3027,9 +3080,40 @@ struct device *tty_register_device(struct tty_driver *driver, unsigned index,
 	else
 		tty_line_name(driver, index, name);
 
-	return device_create(tty_class, device, dev, NULL, name);
+	if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) {
+		retval = tty_cdev_add(driver, devt, index, 1);
+		if (retval)
+			goto error;
+		cdev = true;
+	}
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev) {
+		retval = -ENOMEM;
+		goto error;
+	}
+
+	dev->devt = devt;
+	dev->class = tty_class;
+	dev->parent = device;
+	dev->release = tty_device_create_release;
+	dev_set_name(dev, "%s", name);
+	dev->groups = attr_grp;
+	dev_set_drvdata(dev, drvdata);
+
+	retval = device_register(dev);
+	if (retval)
+		goto error;
+
+	return dev;
+
+error:
+	put_device(dev);
+	if (cdev)
+		cdev_del(&driver->cdevs[index]);
+	return ERR_PTR(retval);
 }
-EXPORT_SYMBOL(tty_register_device);
+EXPORT_SYMBOL_GPL(tty_register_device_attr);
 
 /**
  * 	tty_unregister_device - unregister a tty device
@@ -3046,31 +3130,82 @@ void tty_unregister_device(struct tty_driver *driver, unsigned index)
 {
 	device_destroy(tty_class,
 		MKDEV(driver->major, driver->minor_start) + index);
+	if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC))
+		cdev_del(&driver->cdevs[index]);
 }
 EXPORT_SYMBOL(tty_unregister_device);
 
-struct tty_driver *__alloc_tty_driver(int lines, struct module *owner)
+/**
+ * __tty_alloc_driver -- allocate tty driver
+ * @lines: count of lines this driver can handle at most
+ * @owner: module which is repsonsible for this driver
+ * @flags: some of TTY_DRIVER_* flags, will be set in driver->flags
+ *
+ * This should not be called directly, some of the provided macros should be
+ * used instead. Use IS_ERR and friends on @retval.
+ */
+struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner,
+		unsigned long flags)
 {
 	struct tty_driver *driver;
+	unsigned int cdevs = 1;
+	int err;
+
+	if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1))
+		return ERR_PTR(-EINVAL);
 
 	driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL);
-	if (driver) {
-		kref_init(&driver->kref);
-		driver->magic = TTY_DRIVER_MAGIC;
-		driver->num = lines;
-		driver->owner = owner;
-		/* later we'll move allocation of tables here */
+	if (!driver)
+		return ERR_PTR(-ENOMEM);
+
+	kref_init(&driver->kref);
+	driver->magic = TTY_DRIVER_MAGIC;
+	driver->num = lines;
+	driver->owner = owner;
+	driver->flags = flags;
+
+	if (!(flags & TTY_DRIVER_DEVPTS_MEM)) {
+		driver->ttys = kcalloc(lines, sizeof(*driver->ttys),
+				GFP_KERNEL);
+		driver->termios = kcalloc(lines, sizeof(*driver->termios),
+				GFP_KERNEL);
+		if (!driver->ttys || !driver->termios) {
+			err = -ENOMEM;
+			goto err_free_all;
+		}
+	}
+
+	if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) {
+		driver->ports = kcalloc(lines, sizeof(*driver->ports),
+				GFP_KERNEL);
+		if (!driver->ports) {
+			err = -ENOMEM;
+			goto err_free_all;
+		}
+		cdevs = lines;
 	}
+
+	driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL);
+	if (!driver->cdevs) {
+		err = -ENOMEM;
+		goto err_free_all;
+	}
+
 	return driver;
+err_free_all:
+	kfree(driver->ports);
+	kfree(driver->ttys);
+	kfree(driver->termios);
+	kfree(driver);
+	return ERR_PTR(err);
 }
-EXPORT_SYMBOL(__alloc_tty_driver);
+EXPORT_SYMBOL(__tty_alloc_driver);
 
 static void destruct_tty_driver(struct kref *kref)
 {
 	struct tty_driver *driver = container_of(kref, struct tty_driver, kref);
 	int i;
 	struct ktermios *tp;
-	void *p;
 
 	if (driver->flags & TTY_DRIVER_INSTALLED) {
 		/*
@@ -3087,13 +3222,14 @@ static void destruct_tty_driver(struct kref *kref)
 			if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV))
 				tty_unregister_device(driver, i);
 		}
-		p = driver->ttys;
 		proc_tty_unregister_driver(driver);
-		driver->ttys = NULL;
-		driver->termios = NULL;
-		kfree(p);
-		cdev_del(&driver->cdev);
+		if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)
+			cdev_del(&driver->cdevs[0]);
 	}
+	kfree(driver->cdevs);
+	kfree(driver->ports);
+	kfree(driver->termios);
+	kfree(driver->ttys);
 	kfree(driver);
 }
 
@@ -3124,15 +3260,8 @@ int tty_register_driver(struct tty_driver *driver)
 	int error;
 	int i;
 	dev_t dev;
-	void **p = NULL;
 	struct device *d;
 
-	if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) {
-		p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL);
-		if (!p)
-			return -ENOMEM;
-	}
-
 	if (!driver->major) {
 		error = alloc_chrdev_region(&dev, driver->minor_start,
 						driver->num, driver->name);
@@ -3144,28 +3273,13 @@ int tty_register_driver(struct tty_driver *driver)
 		dev = MKDEV(driver->major, driver->minor_start);
 		error = register_chrdev_region(dev, driver->num, driver->name);
 	}
-	if (error < 0) {
-		kfree(p);
-		return error;
-	}
+	if (error < 0)
+		goto err;
 
-	if (p) {
-		driver->ttys = (struct tty_struct **)p;
-		driver->termios = (struct ktermios **)(p + driver->num);
-	} else {
-		driver->ttys = NULL;
-		driver->termios = NULL;
-	}
-
-	cdev_init(&driver->cdev, &tty_fops);
-	driver->cdev.owner = driver->owner;
-	error = cdev_add(&driver->cdev, dev, driver->num);
-	if (error) {
-		unregister_chrdev_region(dev, driver->num);
-		driver->ttys = NULL;
-		driver->termios = NULL;
-		kfree(p);
-		return error;
+	if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) {
+		error = tty_cdev_add(driver, dev, 0, driver->num);
+		if (error)
+			goto err_unreg_char;
 	}
 
 	mutex_lock(&tty_mutex);
@@ -3177,7 +3291,7 @@ int tty_register_driver(struct tty_driver *driver)
 			d = tty_register_device(driver, i, NULL);
 			if (IS_ERR(d)) {
 				error = PTR_ERR(d);
-				goto err;
+				goto err_unreg_devs;
 			}
 		}
 	}
@@ -3185,7 +3299,7 @@ int tty_register_driver(struct tty_driver *driver)
 	driver->flags |= TTY_DRIVER_INSTALLED;
 	return 0;
 
-err:
+err_unreg_devs:
 	for (i--; i >= 0; i--)
 		tty_unregister_device(driver, i);
 
@@ -3193,13 +3307,11 @@ err:
 	list_del(&driver->tty_drivers);
 	mutex_unlock(&tty_mutex);
 
+err_unreg_char:
 	unregister_chrdev_region(dev, driver->num);
-	driver->ttys = NULL;
-	driver->termios = NULL;
-	kfree(p);
+err:
 	return error;
 }
-
 EXPORT_SYMBOL(tty_register_driver);
 
 /*