X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fchar%2Ftty_io.c;h=1d298c2cf9301c0a1ac2026577463e6a3a6b1813;hb=c92758ceda477b1333fde35327cfa867dcc47bd1;hp=79c86c47947f4da921051be399b028f176f18ad9;hpb=26b6f2236615649a0ae6a0de2e9e71a2f9ffeba7;p=linux-2.6

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 79c86c4794..1d298c2cf9 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -19,7 +19,7 @@
  * Also restructured routines so that there is more of a separation
  * between the high-level tty routines (tty_io.c and tty_ioctl.c) and
  * the low-level tty routines (serial.c, pty.c, console.c).  This
- * makes for cleaner and more compact code.  -TYT, 9/17/92 
+ * makes for cleaner and more compact code.  -TYT, 9/17/92
  *
  * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
  * which can be dynamically activated and de-activated by the line
@@ -41,7 +41,7 @@
  *
  * New TIOCLINUX variants added.
  *	-- mj@k332.feld.cvut.cz, 19-Nov-95
- * 
+ *
  * Restrict vt switching via ioctl()
  *      -- grif@cs.ucr.edu, 5-Dec-95
  *
@@ -62,7 +62,8 @@
  *      -- Russell King <rmk@arm.linux.org.uk>
  *
  * Move do_SAK() into process context.  Less stack use in devfs functions.
- * alloc_tty_struct() always uses kmalloc() -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
+ * alloc_tty_struct() always uses kmalloc()
+ *			 -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
  */
 
 #include <linux/types.h>
@@ -90,7 +91,6 @@
 #include <linux/module.h>
 #include <linux/smp_lock.h>
 #include <linux/device.h>
-#include <linux/idr.h>
 #include <linux/wait.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
@@ -126,7 +126,7 @@ EXPORT_SYMBOL(tty_std_termios);
 /* This list gets poked at by procfs and various bits of boot up code. This
    could do with some rationalisation such as pulling the tty proc function
    into this file */
-   
+
 LIST_HEAD(tty_drivers);			/* linked list of tty drivers */
 
 /* Mutex to protect creating and releasing a tty. This is shared with
@@ -136,9 +136,6 @@ EXPORT_SYMBOL(tty_mutex);
 
 #ifdef CONFIG_UNIX98_PTYS
 extern struct tty_driver *ptm_driver;	/* Unix98 pty masters; for /dev/ptmx */
-extern int pty_limit;		/* Config limit on Unix98 ptys */
-static DEFINE_IDR(allocated_ptys);
-static DEFINE_MUTEX(allocated_ptys_lock);
 static int ptmx_open(struct inode *, struct file *);
 #endif
 
@@ -146,19 +143,19 @@ static void initialize_tty_struct(struct tty_struct *tty);
 
 static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
 static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *);
-ssize_t redirected_tty_write(struct file *, const char __user *, size_t, loff_t *);
+ssize_t redirected_tty_write(struct file *, const char __user *,
+							size_t, loff_t *);
 static unsigned int tty_poll(struct file *, poll_table *);
 static int tty_open(struct inode *, struct file *);
 static int tty_release(struct inode *, struct file *);
-int tty_ioctl(struct inode * inode, struct file * file,
-	      unsigned int cmd, unsigned long arg);
+long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 #ifdef CONFIG_COMPAT
-static long tty_compat_ioctl(struct file * file, unsigned int cmd,
+static long tty_compat_ioctl(struct file *file, unsigned int cmd,
 				unsigned long arg);
 #else
 #define tty_compat_ioctl NULL
 #endif
-static int tty_fasync(int fd, struct file * filp, int on);
+static int tty_fasync(int fd, struct file *filp, int on);
 static void release_tty(struct tty_struct *tty, int idx);
 static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
 static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty);
@@ -244,7 +241,7 @@ static int check_tty_count(struct tty_struct *tty, const char *routine)
 #ifdef CHECK_TTY_COUNT
 	struct list_head *p;
 	int count = 0;
-	
+
 	file_list_lock();
 	list_for_each(p, &tty->tty_files) {
 		count++;
@@ -281,11 +278,11 @@ static int check_tty_count(struct tty_struct *tty, const char *routine)
 static void tty_buffer_free_all(struct tty_struct *tty)
 {
 	struct tty_buffer *thead;
-	while((thead = tty->buf.head) != NULL) {
+	while ((thead = tty->buf.head) != NULL) {
 		tty->buf.head = thead->next;
 		kfree(thead);
 	}
-	while((thead = tty->buf.free) != NULL) {
+	while ((thead = tty->buf.free) != NULL) {
 		tty->buf.free = thead->next;
 		kfree(thead);
 	}
@@ -331,7 +328,7 @@ static struct tty_buffer *tty_buffer_alloc(struct tty_struct *tty, size_t size)
 	if (tty->buf.memory_used + size > 65536)
 		return NULL;
 	p = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC);
-	if(p == NULL)
+	if (p == NULL)
 		return NULL;
 	p->used = 0;
 	p->size = size;
@@ -361,7 +358,7 @@ static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b)
 	tty->buf.memory_used -= b->size;
 	WARN_ON(tty->buf.memory_used < 0);
 
-	if(b->size >= 512)
+	if (b->size >= 512)
 		kfree(b);
 	else {
 		b->next = tty->buf.free;
@@ -384,7 +381,7 @@ static void __tty_buffer_flush(struct tty_struct *tty)
 {
 	struct tty_buffer *thead;
 
-	while((thead = tty->buf.head) != NULL) {
+	while ((thead = tty->buf.head) != NULL) {
 		tty->buf.head = thead->next;
 		tty_buffer_free(tty, thead);
 	}
@@ -436,9 +433,9 @@ static void tty_buffer_flush(struct tty_struct *tty)
 static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
 {
 	struct tty_buffer **tbh = &tty->buf.free;
-	while((*tbh) != NULL) {
+	while ((*tbh) != NULL) {
 		struct tty_buffer *t = *tbh;
-		if(t->size >= size) {
+		if (t->size >= size) {
 			*tbh = t->next;
 			t->next = NULL;
 			t->used = 0;
@@ -450,7 +447,7 @@ static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
 		tbh = &((*tbh)->next);
 	}
 	/* Round the buffer size out */
-	size = (size + 0xFF) & ~ 0xFF;
+	size = (size + 0xFF) & ~0xFF;
 	return tty_buffer_alloc(tty, size);
 	/* Should possibly check if this fails for the largest buffer we
 	   have queued and recycle that ? */
@@ -520,7 +517,7 @@ int tty_insert_flip_string(struct tty_struct *tty, const unsigned char *chars,
 		int space = tty_buffer_request_room(tty, size - copied);
 		struct tty_buffer *tb = tty->buf.tail;
 		/* If there is no space then tb may be NULL */
-		if(unlikely(space == 0))
+		if (unlikely(space == 0))
 			break;
 		memcpy(tb->char_buf_ptr + tb->used, chars, space);
 		memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
@@ -556,7 +553,7 @@ int tty_insert_flip_string_flags(struct tty_struct *tty,
 		int space = tty_buffer_request_room(tty, size - copied);
 		struct tty_buffer *tb = tty->buf.tail;
 		/* If there is no space then tb may be NULL */
-		if(unlikely(space == 0))
+		if (unlikely(space == 0))
 			break;
 		memcpy(tb->char_buf_ptr + tb->used, chars, space);
 		memcpy(tb->flag_buf_ptr + tb->used, flags, space);
@@ -608,7 +605,8 @@ EXPORT_SYMBOL(tty_schedule_flip);
  *	Locking: May call functions taking tty->buf.lock
  */
 
-int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars, size_t size)
+int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars,
+								size_t size)
 {
 	int space = tty_buffer_request_room(tty, size);
 	if (likely(space)) {
@@ -638,7 +636,8 @@ EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
  *	Locking: May call functions taking tty->buf.lock
  */
 
-int tty_prepare_flip_string_flags(struct tty_struct *tty, unsigned char **chars, char **flags, size_t size)
+int tty_prepare_flip_string_flags(struct tty_struct *tty,
+			unsigned char **chars, char **flags, size_t size)
 {
 	int space = tty_buffer_request_room(tty, size);
 	if (likely(space)) {
@@ -660,12 +659,12 @@ EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
  *	@num: line discipline number
  *
  *	This is probably overkill for real world processors but
- *	they are not on hot paths so a little discipline won't do 
+ *	they are not on hot paths so a little discipline won't do
  *	any harm.
  *
  *	Locking: takes termios_mutex
  */
- 
+
 static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
 {
 	mutex_lock(&tty->termios_mutex);
@@ -678,10 +677,11 @@ static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
  *	must be taken with irqs off because there are hangup path
  *	callers who will do ldisc lookups and cannot sleep.
  */
- 
+
 static DEFINE_SPINLOCK(tty_ldisc_lock);
 static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait);
-static struct tty_ldisc tty_ldiscs[NR_LDISCS];	/* line disc dispatch table */
+/* Line disc dispatch table */
+static struct tty_ldisc tty_ldiscs[NR_LDISCS];
 
 /**
  *	tty_register_ldisc	-	install a line discipline
@@ -700,17 +700,17 @@ int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc)
 {
 	unsigned long flags;
 	int ret = 0;
-	
+
 	if (disc < N_TTY || disc >= NR_LDISCS)
 		return -EINVAL;
-	
+
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
 	tty_ldiscs[disc] = *new_ldisc;
 	tty_ldiscs[disc].num = disc;
 	tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED;
 	tty_ldiscs[disc].refcount = 0;
 	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-	
+
 	return ret;
 }
 EXPORT_SYMBOL(tty_register_ldisc);
@@ -766,20 +766,18 @@ struct tty_ldisc *tty_ldisc_get(int disc)
 
 	if (disc < N_TTY || disc >= NR_LDISCS)
 		return NULL;
-	
+
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
 
 	ld = &tty_ldiscs[disc];
 	/* Check the entry is defined */
-	if(ld->flags & LDISC_FLAG_DEFINED)
-	{
+	if (ld->flags & LDISC_FLAG_DEFINED) {
 		/* If the module is being unloaded we can't use it */
 		if (!try_module_get(ld->owner))
-		       	ld = NULL;
+			ld = NULL;
 		else /* lock it */
 			ld->refcount++;
-	}
-	else
+	} else
 		ld = NULL;
 	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
 	return ld;
@@ -802,9 +800,9 @@ void tty_ldisc_put(int disc)
 {
 	struct tty_ldisc *ld;
 	unsigned long flags;
-	
+
 	BUG_ON(disc < N_TTY || disc >= NR_LDISCS);
-		
+
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
 	ld = &tty_ldiscs[disc];
 	BUG_ON(ld->refcount == 0);
@@ -812,7 +810,7 @@ void tty_ldisc_put(int disc)
 	module_put(ld->owner);
 	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
 }
-	
+
 EXPORT_SYMBOL_GPL(tty_ldisc_put);
 
 /**
@@ -851,11 +849,10 @@ static int tty_ldisc_try(struct tty_struct *tty)
 	unsigned long flags;
 	struct tty_ldisc *ld;
 	int ret = 0;
-	
+
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
 	ld = &tty->ldisc;
-	if(test_bit(TTY_LDISC, &tty->flags))
-	{
+	if (test_bit(TTY_LDISC, &tty->flags)) {
 		ld->refcount++;
 		ret = 1;
 	}
@@ -867,8 +864,8 @@ static int tty_ldisc_try(struct tty_struct *tty)
  *	tty_ldisc_ref_wait	-	wait for the tty ldisc
  *	@tty: tty device
  *
- *	Dereference the line discipline for the terminal and take a 
- *	reference to it. If the line discipline is in flux then 
+ *	Dereference the line discipline for the terminal and take a
+ *	reference to it. If the line discipline is in flux then
  *	wait patiently until it changes.
  *
  *	Note: Must not be called from an IRQ/timer context. The caller
@@ -878,12 +875,12 @@ static int tty_ldisc_try(struct tty_struct *tty)
  *
  *	Locking: call functions take tty_ldisc_lock
  */
- 
+
 struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty)
 {
 	/* wait_event is a macro */
 	wait_event(tty_ldisc_wait, tty_ldisc_try(tty));
-	if(tty->ldisc.refcount == 0)
+	if (tty->ldisc.refcount == 0)
 		printk(KERN_ERR "tty_ldisc_ref_wait\n");
 	return &tty->ldisc;
 }
@@ -894,16 +891,16 @@ EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);
  *	tty_ldisc_ref		-	get the tty ldisc
  *	@tty: tty device
  *
- *	Dereference the line discipline for the terminal and take a 
- *	reference to it. If the line discipline is in flux then 
+ *	Dereference the line discipline for the terminal and take a
+ *	reference to it. If the line discipline is in flux then
  *	return NULL. Can be called from IRQ and timer functions.
  *
  *	Locking: called functions take tty_ldisc_lock
  */
- 
+
 struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
 {
-	if(tty_ldisc_try(tty))
+	if (tty_ldisc_try(tty))
 		return &tty->ldisc;
 	return NULL;
 }
@@ -919,19 +916,19 @@ EXPORT_SYMBOL_GPL(tty_ldisc_ref);
  *
  *	Locking: takes tty_ldisc_lock
  */
- 
+
 void tty_ldisc_deref(struct tty_ldisc *ld)
 {
 	unsigned long flags;
 
 	BUG_ON(ld == NULL);
-		
+
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
-	if(ld->refcount == 0)
+	if (ld->refcount == 0)
 		printk(KERN_ERR "tty_ldisc_deref: no references.\n");
 	else
 		ld->refcount--;
-	if(ld->refcount == 0)
+	if (ld->refcount == 0)
 		wake_up(&tty_ldisc_wait);
 	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
 }
@@ -954,7 +951,7 @@ static void tty_ldisc_enable(struct tty_struct *tty)
 	set_bit(TTY_LDISC, &tty->flags);
 	wake_up(&tty_ldisc_wait);
 }
-	
+
 /**
  *	tty_set_ldisc		-	set line discipline
  *	@tty: the terminal to set
@@ -966,7 +963,7 @@ static void tty_ldisc_enable(struct tty_struct *tty)
  *	Locking: takes tty_ldisc_lock.
  *		 called functions take termios_mutex
  */
- 
+
 static int tty_set_ldisc(struct tty_struct *tty, int ldisc)
 {
 	int retval = 0;
@@ -1022,7 +1019,7 @@ restart:
 
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
 	if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) {
-		if(tty->ldisc.refcount) {
+		if (tty->ldisc.refcount) {
 			/* Free the new ldisc we grabbed. Must drop the lock
 			   first. */
 			spin_unlock_irqrestore(&tty_ldisc_lock, flags);
@@ -1031,14 +1028,14 @@ restart:
 			 * There are several reasons we may be busy, including
 			 * random momentary I/O traffic. We must therefore
 			 * retry. We could distinguish between blocking ops
-			 * and retries if we made tty_ldisc_wait() smarter. That
-			 * is up for discussion.
+			 * and retries if we made tty_ldisc_wait() smarter.
+			 * That is up for discussion.
 			 */
 			if (wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0)
 				return -ERESTARTSYS;
 			goto restart;
 		}
-		if(o_tty && o_tty->ldisc.refcount) {
+		if (o_tty && o_tty->ldisc.refcount) {
 			spin_unlock_irqrestore(&tty_ldisc_lock, flags);
 			tty_ldisc_put(ldisc);
 			if (wait_event_interruptible(tty_ldisc_wait, o_tty->ldisc.refcount == 0) < 0)
@@ -1046,9 +1043,10 @@ restart:
 			goto restart;
 		}
 	}
-
-	/* if the TTY_LDISC bit is set, then we are racing against another ldisc change */
-
+	/*
+	 *	If the TTY_LDISC bit is set, then we are racing against
+	 *	another ldisc change
+	 */
 	if (!test_bit(TTY_LDISC, &tty->flags)) {
 		spin_unlock_irqrestore(&tty_ldisc_lock, flags);
 		tty_ldisc_put(ldisc);
@@ -1072,7 +1070,6 @@ restart:
 	/*
 	 * Wait for ->hangup_work and ->buf.work handlers to terminate
 	 */
-	 
 	flush_scheduled_work();
 	/* Shutdown the current discipline. */
 	if (tty->ldisc.close)
@@ -1106,21 +1103,21 @@ restart:
 	/* At this point we hold a reference to the new ldisc and a
 	   a reference to the old ldisc. If we ended up flipping back
 	   to the existing ldisc we have two references to it */
-	
-	if (tty->ldisc.num != o_ldisc.num && tty->driver->set_ldisc)
-		tty->driver->set_ldisc(tty);
-		
+
+	if (tty->ldisc.num != o_ldisc.num && tty->ops->set_ldisc)
+		tty->ops->set_ldisc(tty);
+
 	tty_ldisc_put(o_ldisc.num);
-	
+
 	/*
 	 *	Allow ldisc referencing to occur as soon as the driver
 	 *	ldisc callback completes.
 	 */
-	 
+
 	tty_ldisc_enable(tty);
 	if (o_tty)
 		tty_ldisc_enable(o_tty);
-	
+
 	/* Restart it in case no characters kick it off. Safe if
 	   already running */
 	if (work)
@@ -1153,6 +1150,47 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index)
 	return NULL;
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+
+/**
+ *	tty_find_polling_driver	-	find device of a polled tty
+ *	@name: name string to match
+ *	@line: pointer to resulting tty line nr
+ *
+ *	This routine returns a tty driver structure, given a name
+ *	and the condition that the tty driver is capable of polled
+ *	operation.
+ */
+struct tty_driver *tty_find_polling_driver(char *name, int *line)
+{
+	struct tty_driver *p, *res = NULL;
+	int tty_line = 0;
+	char *str;
+
+	mutex_lock(&tty_mutex);
+	/* Search through the tty devices to look for a match */
+	list_for_each_entry(p, &tty_drivers, tty_drivers) {
+		str = name + strlen(p->name);
+		tty_line = simple_strtoul(str, &str, 10);
+		if (*str == ',')
+			str++;
+		if (*str == '\0')
+			str = NULL;
+
+		if (tty_line >= 0 && tty_line <= p->num && p->ops &&
+		    p->ops->poll_init && !p->ops->poll_init(p, tty_line, str)) {
+			res = p;
+			*line = tty_line;
+			break;
+		}
+	}
+	mutex_unlock(&tty_mutex);
+
+	return res;
+}
+EXPORT_SYMBOL_GPL(tty_find_polling_driver);
+#endif
+
 /**
  *	tty_check_change	-	check for POSIX terminal changes
  *	@tty: tty to check
@@ -1161,55 +1199,66 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index)
  *	not in the foreground, send a SIGTTOU.  If the signal is blocked or
  *	ignored, go ahead and perform the operation.  (POSIX 7.2)
  *
- *	Locking: none
+ *	Locking: ctrl_lock
  */
 
-int tty_check_change(struct tty_struct * tty)
+int tty_check_change(struct tty_struct *tty)
 {
+	unsigned long flags;
+	int ret = 0;
+
 	if (current->signal->tty != tty)
 		return 0;
+
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+
 	if (!tty->pgrp) {
 		printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n");
-		return 0;
+		goto out;
 	}
 	if (task_pgrp(current) == tty->pgrp)
-		return 0;
+		goto out;
 	if (is_ignored(SIGTTOU))
-		return 0;
-	if (is_current_pgrp_orphaned())
-		return -EIO;
+		goto out;
+	if (is_current_pgrp_orphaned()) {
+		ret = -EIO;
+		goto out;
+	}
 	kill_pgrp(task_pgrp(current), SIGTTOU, 1);
 	set_thread_flag(TIF_SIGPENDING);
-	return -ERESTARTSYS;
+	ret = -ERESTARTSYS;
+out:
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+	return ret;
 }
 
 EXPORT_SYMBOL(tty_check_change);
 
-static ssize_t hung_up_tty_read(struct file * file, char __user * buf,
+static ssize_t hung_up_tty_read(struct file *file, char __user *buf,
 				size_t count, loff_t *ppos)
 {
 	return 0;
 }
 
-static ssize_t hung_up_tty_write(struct file * file, const char __user * buf,
+static ssize_t hung_up_tty_write(struct file *file, const char __user *buf,
 				 size_t count, loff_t *ppos)
 {
 	return -EIO;
 }
 
 /* No kernel lock held - none needed ;) */
-static unsigned int hung_up_tty_poll(struct file * filp, poll_table * wait)
+static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait)
 {
 	return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM;
 }
 
-static int hung_up_tty_ioctl(struct inode * inode, struct file * file,
-			     unsigned int cmd, unsigned long arg)
+static long hung_up_tty_ioctl(struct file *file, unsigned int cmd,
+		unsigned long arg)
 {
 	return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
 }
 
-static long hung_up_tty_compat_ioctl(struct file * file,
+static long hung_up_tty_compat_ioctl(struct file *file,
 				     unsigned int cmd, unsigned long arg)
 {
 	return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
@@ -1220,7 +1269,7 @@ static const struct file_operations tty_fops = {
 	.read		= tty_read,
 	.write		= tty_write,
 	.poll		= tty_poll,
-	.ioctl		= tty_ioctl,
+	.unlocked_ioctl	= tty_ioctl,
 	.compat_ioctl	= tty_compat_ioctl,
 	.open		= tty_open,
 	.release	= tty_release,
@@ -1233,7 +1282,7 @@ static const struct file_operations ptmx_fops = {
 	.read		= tty_read,
 	.write		= tty_write,
 	.poll		= tty_poll,
-	.ioctl		= tty_ioctl,
+	.unlocked_ioctl	= tty_ioctl,
 	.compat_ioctl	= tty_compat_ioctl,
 	.open		= ptmx_open,
 	.release	= tty_release,
@@ -1246,7 +1295,7 @@ static const struct file_operations console_fops = {
 	.read		= tty_read,
 	.write		= redirected_tty_write,
 	.poll		= tty_poll,
-	.ioctl		= tty_ioctl,
+	.unlocked_ioctl	= tty_ioctl,
 	.compat_ioctl	= tty_compat_ioctl,
 	.open		= tty_open,
 	.release	= tty_release,
@@ -1258,7 +1307,7 @@ static const struct file_operations hung_up_tty_fops = {
 	.read		= hung_up_tty_read,
 	.write		= hung_up_tty_write,
 	.poll		= hung_up_tty_poll,
-	.ioctl		= hung_up_tty_ioctl,
+	.unlocked_ioctl	= hung_up_tty_ioctl,
 	.compat_ioctl	= hung_up_tty_compat_ioctl,
 	.release	= tty_release,
 };
@@ -1274,15 +1323,15 @@ static struct file *redirect;
  *	informs the line discipline if present that the driver is ready
  *	to receive more output data.
  */
- 
+
 void tty_wakeup(struct tty_struct *tty)
 {
 	struct tty_ldisc *ld;
-	
+
 	if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) {
 		ld = tty_ldisc_ref(tty);
-		if(ld) {
-			if(ld->write_wakeup)
+		if (ld) {
+			if (ld->write_wakeup)
 				ld->write_wakeup(tty);
 			tty_ldisc_deref(ld);
 		}
@@ -1299,12 +1348,12 @@ EXPORT_SYMBOL_GPL(tty_wakeup);
  *	Flush the line discipline queue (if any) for this tty. If there
  *	is no line discipline active this is a no-op.
  */
- 
+
 void tty_ldisc_flush(struct tty_struct *tty)
 {
 	struct tty_ldisc *ld = tty_ldisc_ref(tty);
-	if(ld) {
-		if(ld->flush_buffer)
+	if (ld) {
+		if (ld->flush_buffer)
 			ld->flush_buffer(tty);
 		tty_ldisc_deref(ld);
 	}
@@ -1328,7 +1377,7 @@ static void tty_reset_termios(struct tty_struct *tty)
 	tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
 	mutex_unlock(&tty->termios_mutex);
 }
-	
+
 /**
  *	do_tty_hangup		-	actual handler for hangup events
  *	@work: tty device
@@ -1355,11 +1404,12 @@ static void do_tty_hangup(struct work_struct *work)
 {
 	struct tty_struct *tty =
 		container_of(work, struct tty_struct, hangup_work);
-	struct file * cons_filp = NULL;
+	struct file *cons_filp = NULL;
 	struct file *filp, *f = NULL;
 	struct task_struct *p;
 	struct tty_ldisc *ld;
 	int    closecount = 0, n;
+	unsigned long flags;
 
 	if (!tty)
 		return;
@@ -1373,7 +1423,7 @@ static void do_tty_hangup(struct work_struct *work)
 		redirect = NULL;
 	}
 	spin_unlock(&redirect_lock);
-	
+
 	check_tty_count(tty, "do_tty_hangup");
 	file_list_lock();
 	/* This breaks for file handles being sent over AF_UNIX sockets ? */
@@ -1387,43 +1437,41 @@ static void do_tty_hangup(struct work_struct *work)
 		filp->f_op = &hung_up_tty_fops;
 	}
 	file_list_unlock();
-	
-	/* FIXME! What are the locking issues here? This may me overdoing things..
-	 * this question is especially important now that we've removed the irqlock. */
-
+	/*
+	 * FIXME! What are the locking issues here? This may me overdoing
+	 * things... This question is especially important now that we've
+	 * removed the irqlock.
+	 */
 	ld = tty_ldisc_ref(tty);
-	if(ld != NULL)	/* We may have no line discipline at this point */
-	{
+	if (ld != NULL) {
+		/* We may have no line discipline at this point */
 		if (ld->flush_buffer)
 			ld->flush_buffer(tty);
-		if (tty->driver->flush_buffer)
-			tty->driver->flush_buffer(tty);
+		tty_driver_flush_buffer(tty);
 		if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
 		    ld->write_wakeup)
 			ld->write_wakeup(tty);
 		if (ld->hangup)
 			ld->hangup(tty);
 	}
-
-	/* FIXME: Once we trust the LDISC code better we can wait here for
-	   ldisc completion and fix the driver call race */
-	   
+	/*
+	 * FIXME: Once we trust the LDISC code better we can wait here for
+	 * ldisc completion and fix the driver call race
+	 */
 	wake_up_interruptible(&tty->write_wait);
 	wake_up_interruptible(&tty->read_wait);
-
 	/*
 	 * Shutdown the current line discipline, and reset it to
 	 * N_TTY.
 	 */
 	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
 		tty_reset_termios(tty);
-	
 	/* Defer ldisc switch */
 	/* tty_deferred_ldisc_switch(N_TTY);
-	
+
 	  This should get done automatically when the port closes and
 	  tty_release is called */
-	
+
 	read_lock(&tasklist_lock);
 	if (tty->session) {
 		do_each_pid_task(tty->session, PIDTYPE_SID, p) {
@@ -1437,37 +1485,42 @@ static void do_tty_hangup(struct work_struct *work)
 			__group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p);
 			__group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p);
 			put_pid(p->signal->tty_old_pgrp);  /* A noop */
+			spin_lock_irqsave(&tty->ctrl_lock, flags);
 			if (tty->pgrp)
 				p->signal->tty_old_pgrp = get_pid(tty->pgrp);
+			spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 			spin_unlock_irq(&p->sighand->siglock);
 		} while_each_pid_task(tty->session, PIDTYPE_SID, p);
 	}
 	read_unlock(&tasklist_lock);
 
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
 	tty->flags = 0;
 	put_pid(tty->session);
 	put_pid(tty->pgrp);
 	tty->session = NULL;
 	tty->pgrp = NULL;
 	tty->ctrl_status = 0;
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
 	/*
-	 *	If one of the devices matches a console pointer, we
-	 *	cannot just call hangup() because that will cause
-	 *	tty->count and state->count to go out of sync.
-	 *	So we just call close() the right number of times.
+	 * If one of the devices matches a console pointer, we
+	 * cannot just call hangup() because that will cause
+	 * tty->count and state->count to go out of sync.
+	 * So we just call close() the right number of times.
 	 */
 	if (cons_filp) {
-		if (tty->driver->close)
+		if (tty->ops->close)
 			for (n = 0; n < closecount; n++)
-				tty->driver->close(tty, cons_filp);
-	} else if (tty->driver->hangup)
-		(tty->driver->hangup)(tty);
-		
-	/* We don't want to have driver/ldisc interactions beyond
-	   the ones we did here. The driver layer expects no
-	   calls after ->hangup() from the ldisc side. However we
-	   can't yet guarantee all that */
-
+				tty->ops->close(tty, cons_filp);
+	} else if (tty->ops->hangup)
+		(tty->ops->hangup)(tty);
+	/*
+	 * We don't want to have driver/ldisc interactions beyond
+	 * the ones we did here. The driver layer expects no
+	 * calls after ->hangup() from the ldisc side. However we
+	 * can't yet guarantee all that.
+	 */
 	set_bit(TTY_HUPPED, &tty->flags);
 	if (ld) {
 		tty_ldisc_enable(tty);
@@ -1486,11 +1539,10 @@ static void do_tty_hangup(struct work_struct *work)
  *	schedule a hangup sequence to run after this event.
  */
 
-void tty_hangup(struct tty_struct * tty)
+void tty_hangup(struct tty_struct *tty)
 {
 #ifdef TTY_DEBUG_HANGUP
 	char	buf[64];
-	
 	printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf));
 #endif
 	schedule_work(&tty->hangup_work);
@@ -1507,7 +1559,7 @@ EXPORT_SYMBOL(tty_hangup);
  *	is complete. That guarantee is necessary for security reasons.
  */
 
-void tty_vhangup(struct tty_struct * tty)
+void tty_vhangup(struct tty_struct *tty)
 {
 #ifdef TTY_DEBUG_HANGUP
 	char	buf[64];
@@ -1516,6 +1568,7 @@ void tty_vhangup(struct tty_struct * tty)
 #endif
 	do_tty_hangup(&tty->hangup_work);
 }
+
 EXPORT_SYMBOL(tty_vhangup);
 
 /**
@@ -1526,7 +1579,7 @@ EXPORT_SYMBOL(tty_vhangup);
  *	loss
  */
 
-int tty_hung_up_p(struct file * filp)
+int tty_hung_up_p(struct file *filp)
 {
 	return (filp->f_op == &hung_up_tty_fops);
 }
@@ -1534,8 +1587,12 @@ int tty_hung_up_p(struct file * filp)
 EXPORT_SYMBOL(tty_hung_up_p);
 
 /**
- * is_tty	-	checker whether file is a TTY
+ *	is_tty	-	checker whether file is a TTY
+ *	@filp:		file handle that may be a tty
+ *
+ *	Check if the file handle is a tty handle.
  */
+
 int is_tty(struct file *filp)
 {
 	return filp->f_op->read == tty_read
@@ -1579,16 +1636,17 @@ void disassociate_ctty(int on_exit)
 	struct tty_struct *tty;
 	struct pid *tty_pgrp = NULL;
 
-	lock_kernel();
 
 	mutex_lock(&tty_mutex);
 	tty = get_current_tty();
 	if (tty) {
 		tty_pgrp = get_pid(tty->pgrp);
 		mutex_unlock(&tty_mutex);
+		lock_kernel();
 		/* XXX: here we race, there is nothing protecting tty */
 		if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY)
 			tty_vhangup(tty);
+		unlock_kernel();
 	} else if (on_exit) {
 		struct pid *old_pgrp;
 		spin_lock_irq(&current->sighand->siglock);
@@ -1601,7 +1659,6 @@ void disassociate_ctty(int on_exit)
 			put_pid(old_pgrp);
 		}
 		mutex_unlock(&tty_mutex);
-		unlock_kernel();	
 		return;
 	}
 	if (tty_pgrp) {
@@ -1620,10 +1677,13 @@ void disassociate_ctty(int on_exit)
 	/* It is possible that do_tty_hangup has free'd this tty */
 	tty = get_current_tty();
 	if (tty) {
+		unsigned long flags;
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
 		put_pid(tty->session);
 		put_pid(tty->pgrp);
 		tty->session = NULL;
 		tty->pgrp = NULL;
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 	} else {
 #ifdef TTY_DEBUG_HANGUP
 		printk(KERN_DEBUG "error attempted to write to tty [0x%p]"
@@ -1636,7 +1696,6 @@ void disassociate_ctty(int on_exit)
 	read_lock(&tasklist_lock);
 	session_clear_tty(task_session(current));
 	read_unlock(&tasklist_lock);
-	unlock_kernel();
 }
 
 /**
@@ -1646,8 +1705,10 @@ void disassociate_ctty(int on_exit)
 void no_tty(void)
 {
 	struct task_struct *tsk = current;
+	lock_kernel();
 	if (tsk->signal->leader)
 		disassociate_ctty(0);
+	unlock_kernel();
 	proc_clear_tty(tsk);
 }
 
@@ -1667,21 +1728,26 @@ void no_tty(void)
  *	but not always.
  *
  *	Locking:
- *		Broken. Relies on BKL which is unsafe here.
+ *		Uses the tty control lock internally
  */
 
 void stop_tty(struct tty_struct *tty)
 {
-	if (tty->stopped)
+	unsigned long flags;
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	if (tty->stopped) {
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 		return;
+	}
 	tty->stopped = 1;
 	if (tty->link && tty->link->packet) {
 		tty->ctrl_status &= ~TIOCPKT_START;
 		tty->ctrl_status |= TIOCPKT_STOP;
 		wake_up_interruptible(&tty->link->read_wait);
 	}
-	if (tty->driver->stop)
-		(tty->driver->stop)(tty);
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+	if (tty->ops->stop)
+		(tty->ops->stop)(tty);
 }
 
 EXPORT_SYMBOL(stop_tty);
@@ -1696,22 +1762,26 @@ EXPORT_SYMBOL(stop_tty);
  *	driver start method is invoked and the line discipline woken.
  *
  *	Locking:
- *		Broken. Relies on BKL which is unsafe here.
+ *		ctrl_lock
  */
 
 void start_tty(struct tty_struct *tty)
 {
-	if (!tty->stopped || tty->flow_stopped)
+	unsigned long flags;
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	if (!tty->stopped || tty->flow_stopped) {
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 		return;
+	}
 	tty->stopped = 0;
 	if (tty->link && tty->link->packet) {
 		tty->ctrl_status &= ~TIOCPKT_STOP;
 		tty->ctrl_status |= TIOCPKT_START;
 		wake_up_interruptible(&tty->link->read_wait);
 	}
-	if (tty->driver->start)
-		(tty->driver->start)(tty);
-
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+	if (tty->ops->start)
+		(tty->ops->start)(tty);
 	/* If we have a running line discipline it may need kicking */
 	tty_wakeup(tty);
 }
@@ -1729,17 +1799,15 @@ EXPORT_SYMBOL(start_tty);
  *	for hung up devices before calling the line discipline method.
  *
  *	Locking:
- *		Locks the line discipline internally while needed
- *		For historical reasons the line discipline read method is
- *	invoked under the BKL. This will go away in time so do not rely on it
- *	in new code. Multiple read calls may be outstanding in parallel.
+ *		Locks the line discipline internally while needed. Multiple
+ *	read calls may be outstanding in parallel.
  */
 
-static ssize_t tty_read(struct file * file, char __user * buf, size_t count, 
+static ssize_t tty_read(struct file *file, char __user *buf, size_t count,
 			loff_t *ppos)
 {
 	int i;
-	struct tty_struct * tty;
+	struct tty_struct *tty;
 	struct inode *inode;
 	struct tty_ldisc *ld;
 
@@ -1753,13 +1821,11 @@ static ssize_t tty_read(struct file * file, char __user * buf, size_t count,
 	/* We want to wait for the line discipline to sort out in this
 	   situation */
 	ld = tty_ldisc_ref_wait(tty);
-	lock_kernel();
 	if (ld->read)
-		i = (ld->read)(tty,file,buf,count);
+		i = (ld->read)(tty, file, buf, count);
 	else
 		i = -EIO;
 	tty_ldisc_deref(ld);
-	unlock_kernel();
 	if (i > 0)
 		inode->i_atime = current_fs_time(inode->i_sb);
 	return i;
@@ -1795,7 +1861,7 @@ static inline ssize_t do_tty_write(
 {
 	ssize_t ret, written = 0;
 	unsigned int chunk;
-	
+
 	ret = tty_write_lock(tty, file->f_flags & O_NDELAY);
 	if (ret < 0)
 		return ret;
@@ -1847,9 +1913,7 @@ static inline ssize_t do_tty_write(
 		ret = -EFAULT;
 		if (copy_from_user(tty->write_buf, buf, size))
 			break;
-		lock_kernel();
 		ret = write(tty, file, tty->write_buf, size);
-		unlock_kernel();
 		if (ret <= 0)
 			break;
 		written += ret;
@@ -1891,21 +1955,25 @@ out:
  *	kernel lock for historical reasons. New code should not rely on this.
  */
 
-static ssize_t tty_write(struct file * file, const char __user * buf, size_t count,
-			 loff_t *ppos)
+static ssize_t tty_write(struct file *file, const char __user *buf,
+						size_t count, loff_t *ppos)
 {
-	struct tty_struct * tty;
+	struct tty_struct *tty;
 	struct inode *inode = file->f_path.dentry->d_inode;
 	ssize_t ret;
 	struct tty_ldisc *ld;
-	
+
 	tty = (struct tty_struct *)file->private_data;
 	if (tty_paranoia_check(tty, inode, "tty_write"))
 		return -EIO;
-	if (!tty || !tty->driver->write || (test_bit(TTY_IO_ERROR, &tty->flags)))
-		return -EIO;
-
-	ld = tty_ldisc_ref_wait(tty);		
+	if (!tty || !tty->ops->write ||
+		(test_bit(TTY_IO_ERROR, &tty->flags)))
+			return -EIO;
+	/* Short term debug to catch buggy drivers */
+	if (tty->ops->write_room == NULL)
+		printk(KERN_ERR "tty driver %s lacks a write_room method.\n",
+			tty->driver->name);
+	ld = tty_ldisc_ref_wait(tty);
 	if (!ld->write)
 		ret = -EIO;
 	else
@@ -1914,8 +1982,8 @@ static ssize_t tty_write(struct file * file, const char __user * buf, size_t cou
 	return ret;
 }
 
-ssize_t redirected_tty_write(struct file * file, const char __user * buf, size_t count,
-			 loff_t *ppos)
+ssize_t redirected_tty_write(struct file *file, const char __user *buf,
+						size_t count, loff_t *ppos)
 {
 	struct file *p = NULL;
 
@@ -1932,7 +2000,6 @@ ssize_t redirected_tty_write(struct file * file, const char __user * buf, size_t
 		fput(p);
 		return res;
 	}
-
 	return tty_write(file, buf, count, ppos);
 }
 
@@ -1954,8 +2021,8 @@ static void pty_line_name(struct tty_driver *driver, int index, char *p)
 	int i = index + driver->name_base;
 	/* ->name is initialized to "ttyp", but "tty" is expected */
 	sprintf(p, "%s%c%x",
-			driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name,
-			ptychar[i >> 4 & 0xf], i & 0xf);
+		driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name,
+		ptychar[i >> 4 & 0xf], i & 0xf);
 }
 
 /**
@@ -2034,7 +2101,7 @@ static int init_dev(struct tty_driver *driver, int idx,
 	 * First time open is complex, especially for PTY devices.
 	 * This code guarantees that either everything succeeds and the
 	 * TTY is ready for operation, or else the table slots are vacated
-	 * and the allocated memory released.  (Except that the termios 
+	 * and the allocated memory released.  (Except that the termios
 	 * and locked termios may be retained.)
 	 */
 
@@ -2048,10 +2115,11 @@ static int init_dev(struct tty_driver *driver, int idx,
 	ltp = o_ltp = NULL;
 
 	tty = alloc_tty_struct();
-	if(!tty)
+	if (!tty)
 		goto fail_no_mem;
 	initialize_tty_struct(tty);
 	tty->driver = driver;
+	tty->ops = driver->ops;
 	tty->index = idx;
 	tty_line_name(driver, idx, tty->name);
 
@@ -2082,6 +2150,7 @@ static int init_dev(struct tty_driver *driver, int idx,
 			goto free_mem_out;
 		initialize_tty_struct(o_tty);
 		o_tty->driver = driver->other;
+		o_tty->ops = driver->ops;
 		o_tty->index = idx;
 		tty_line_name(driver->other, idx, o_tty->name);
 
@@ -2109,9 +2178,8 @@ static int init_dev(struct tty_driver *driver, int idx,
 		/*
 		 * Everything allocated ... set up the o_tty structure.
 		 */
-		if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM)) {
+		if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM))
 			driver->other->ttys[idx] = o_tty;
-		}
 		if (!*o_tp_loc)
 			*o_tp_loc = o_tp;
 		if (!*o_ltp_loc)
@@ -2127,15 +2195,14 @@ static int init_dev(struct tty_driver *driver, int idx,
 		o_tty->link = tty;
 	}
 
-	/* 
+	/*
 	 * All structures have been allocated, so now we install them.
 	 * Failures after this point use release_tty to clean up, so
 	 * there's no need to null out the local pointers.
 	 */
-	if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+	if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM))
 		driver->ttys[idx] = tty;
-	}
-	
+
 	if (!*tp_loc)
 		*tp_loc = tp;
 	if (!*ltp_loc)
@@ -2148,7 +2215,7 @@ static int init_dev(struct tty_driver *driver, int idx,
 	driver->refcount++;
 	tty->count++;
 
-	/* 
+	/*
 	 * Structures all installed ... call the ldisc open routines.
 	 * If we fail here just call release_tty to clean up.  No need
 	 * to decrement the use counts, as release_tty doesn't care.
@@ -2185,7 +2252,7 @@ fast_track:
 	if (driver->type == TTY_DRIVER_TYPE_PTY &&
 	    driver->subtype == PTY_TYPE_MASTER) {
 		/*
-		 * special case for PTY masters: only one open permitted, 
+		 * special case for PTY masters: only one open permitted,
 		 * and the slave side open count is incremented as well.
 		 */
 		if (tty->count) {
@@ -2198,11 +2265,11 @@ fast_track:
 	tty->driver = driver; /* N.B. why do this every time?? */
 
 	/* FIXME */
-	if(!test_bit(TTY_LDISC, &tty->flags))
+	if (!test_bit(TTY_LDISC, &tty->flags))
 		printk(KERN_ERR "init_dev but no ldisc\n");
 success:
 	*ret_tty = tty;
-	
+
 	/* All paths come through here to release the mutex */
 end_init:
 	return retval;
@@ -2304,7 +2371,7 @@ static void release_tty(struct tty_struct *tty, int idx)
  * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
  * lead to double frees or releasing memory still in use.
  */
-static void release_dev(struct file * filp)
+static void release_dev(struct file *filp)
 {
 	struct tty_struct *tty, *o_tty;
 	int	pty_master, tty_closing, o_tty_closing, do_sleep;
@@ -2312,9 +2379,10 @@ static void release_dev(struct file * filp)
 	int	idx;
 	char	buf[64];
 	unsigned long flags;
-	
+
 	tty = (struct tty_struct *)filp->private_data;
-	if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "release_dev"))
+	if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode,
+							"release_dev"))
 		return;
 
 	check_tty_count(tty, "release_dev");
@@ -2374,7 +2442,7 @@ static void release_dev(struct file * filp)
 			       idx, tty->name);
 			return;
 		}
-		if (o_tty->termios_locked != 
+		if (o_tty->termios_locked !=
 		      tty->driver->other->termios_locked[idx]) {
 			printk(KERN_DEBUG "release_dev: other->termios_locked["
 					  "%d] not o_termios_locked for (%s)\n",
@@ -2387,8 +2455,8 @@ static void release_dev(struct file * filp)
 		}
 	}
 #endif
-	if (tty->driver->close)
-		tty->driver->close(tty, filp);
+	if (tty->ops->close)
+		tty->ops->close(tty, filp);
 
 	/*
 	 * Sanity check: if tty->count is going to zero, there shouldn't be
@@ -2410,7 +2478,7 @@ static void release_dev(struct file * filp)
 	while (1) {
 		/* Guard against races with tty->count changes elsewhere and
 		   opens on /dev/tty */
-		   
+
 		mutex_lock(&tty_mutex);
 		tty_closing = tty->count <= 1;
 		o_tty_closing = o_tty &&
@@ -2444,11 +2512,11 @@ static void release_dev(struct file * filp)
 				    "active!\n", tty_name(tty, buf));
 		mutex_unlock(&tty_mutex);
 		schedule();
-	}	
+	}
 
 	/*
-	 * The closing flags are now consistent with the open counts on 
-	 * both sides, and we've completed the last operation that could 
+	 * 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.
 	 */
 	if (pty_master) {
@@ -2464,7 +2532,7 @@ static void release_dev(struct file * filp)
 		       tty->count, tty_name(tty, buf));
 		tty->count = 0;
 	}
-	
+
 	/*
 	 * We've decremented tty->count, so we need to remove this file
 	 * descriptor off the tty->tty_files list; this serves two
@@ -2484,9 +2552,9 @@ static void release_dev(struct file * filp)
 	 * case of a pty we may have to wait around for the other side
 	 * to close, and TTY_CLOSING makes sure we can't be reopened.
 	 */
-	if(tty_closing)
+	if (tty_closing)
 		set_bit(TTY_CLOSING, &tty->flags);
-	if(o_tty_closing)
+	if (o_tty_closing)
 		set_bit(TTY_CLOSING, &o_tty->flags);
 
 	/*
@@ -2507,7 +2575,7 @@ static void release_dev(struct file * filp)
 	/* check whether both sides are closing ... */
 	if (!tty_closing || (o_tty && !o_tty_closing))
 		return;
-	
+
 #ifdef TTY_DEBUG_HANGUP
 	printk(KERN_DEBUG "freeing tty structure...");
 #endif
@@ -2522,17 +2590,16 @@ static void release_dev(struct file * filp)
 	/*
 	 * Wait for ->hangup_work and ->buf.work handlers to terminate
 	 */
-	 
+
 	flush_scheduled_work();
-	
+
 	/*
 	 * Wait for any short term users (we know they are just driver
 	 * side waiters as the file is closing so user count on the file
 	 * side is zero.
 	 */
 	spin_lock_irqsave(&tty_ldisc_lock, flags);
-	while(tty->ldisc.refcount)
-	{
+	while (tty->ldisc.refcount) {
 		spin_unlock_irqrestore(&tty_ldisc_lock, flags);
 		wait_event(tty_ldisc_wait, tty->ldisc.refcount == 0);
 		spin_lock_irqsave(&tty_ldisc_lock, flags);
@@ -2547,12 +2614,12 @@ static void release_dev(struct file * filp)
 	if (tty->ldisc.close)
 		(tty->ldisc.close)(tty);
 	tty_ldisc_put(tty->ldisc.num);
-	
+
 	/*
 	 *	Switch the line discipline back
 	 */
 	tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
-	tty_set_termios_ldisc(tty,N_TTY); 
+	tty_set_termios_ldisc(tty, N_TTY);
 	if (o_tty) {
 		/* FIXME: could o_tty be in setldisc here ? */
 		clear_bit(TTY_LDISC, &o_tty->flags);
@@ -2560,7 +2627,7 @@ static void release_dev(struct file * filp)
 			(o_tty->ldisc.close)(o_tty);
 		tty_ldisc_put(o_tty->ldisc.num);
 		tty_ldisc_assign(o_tty, tty_ldisc_get(N_TTY));
-		tty_set_termios_ldisc(o_tty,N_TTY); 
+		tty_set_termios_ldisc(o_tty, N_TTY);
 	}
 	/*
 	 * The release_tty function takes care of the details of clearing
@@ -2568,15 +2635,9 @@ static void release_dev(struct file * filp)
 	 */
 	release_tty(tty, idx);
 
-#ifdef CONFIG_UNIX98_PTYS
 	/* Make this pty number available for reallocation */
-	if (devpts) {
-		mutex_lock(&allocated_ptys_lock);
-		idr_remove(&allocated_ptys, idx);
-		mutex_unlock(&allocated_ptys_lock);
-	}
-#endif
-
+	if (devpts)
+		devpts_kill_index(idx);
 }
 
 /**
@@ -2600,7 +2661,7 @@ static void release_dev(struct file * filp)
  *		 ->siglock protects ->signal/->sighand
  */
 
-static int tty_open(struct inode * inode, struct file * filp)
+static int tty_open(struct inode *inode, struct file *filp)
 {
 	struct tty_struct *tty;
 	int noctty, retval;
@@ -2610,15 +2671,15 @@ static int tty_open(struct inode * inode, struct file * filp)
 	unsigned short saved_flags = filp->f_flags;
 
 	nonseekable_open(inode, filp);
-	
+
 retry_open:
 	noctty = filp->f_flags & O_NOCTTY;
 	index  = -1;
 	retval = 0;
-	
+
 	mutex_lock(&tty_mutex);
 
-	if (device == MKDEV(TTYAUX_MAJOR,0)) {
+	if (device == MKDEV(TTYAUX_MAJOR, 0)) {
 		tty = get_current_tty();
 		if (!tty) {
 			mutex_unlock(&tty_mutex);
@@ -2631,7 +2692,7 @@ retry_open:
 		goto got_driver;
 	}
 #ifdef CONFIG_VT
-	if (device == MKDEV(TTY_MAJOR,0)) {
+	if (device == MKDEV(TTY_MAJOR, 0)) {
 		extern struct tty_driver *console_driver;
 		driver = console_driver;
 		index = fg_console;
@@ -2639,7 +2700,7 @@ retry_open:
 		goto got_driver;
 	}
 #endif
-	if (device == MKDEV(TTYAUX_MAJOR,1)) {
+	if (device == MKDEV(TTYAUX_MAJOR, 1)) {
 		driver = console_device(&index);
 		if (driver) {
 			/* Don't let /dev/console block */
@@ -2672,14 +2733,15 @@ got_driver:
 	printk(KERN_DEBUG "opening %s...", tty->name);
 #endif
 	if (!retval) {
-		if (tty->driver->open)
-			retval = tty->driver->open(tty, filp);
+		if (tty->ops->open)
+			retval = tty->ops->open(tty, filp);
 		else
 			retval = -ENODEV;
 	}
 	filp->f_flags = saved_flags;
 
-	if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN))
+	if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) &&
+						!capable(CAP_SYS_ADMIN))
 		retval = -EBUSY;
 
 	if (retval) {
@@ -2710,7 +2772,6 @@ got_driver:
 		__proc_set_tty(current, tty);
 	spin_unlock_irq(&current->sighand->siglock);
 	mutex_unlock(&tty_mutex);
-	tty_audit_opening();
 	return 0;
 }
 
@@ -2723,43 +2784,27 @@ got_driver:
  *	Allocate a unix98 pty master device from the ptmx driver.
  *
  *	Locking: tty_mutex protects theinit_dev work. tty->count should
- 		protect the rest.
+ * 		protect the rest.
  *		allocated_ptys_lock handles the list of free pty numbers
  */
 
-static int ptmx_open(struct inode * inode, struct file * filp)
+static int ptmx_open(struct inode *inode, struct file *filp)
 {
 	struct tty_struct *tty;
 	int retval;
 	int index;
-	int idr_ret;
 
 	nonseekable_open(inode, filp);
 
 	/* find a device that is not in use. */
-	mutex_lock(&allocated_ptys_lock);
-	if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) {
-		mutex_unlock(&allocated_ptys_lock);
-		return -ENOMEM;
-	}
-	idr_ret = idr_get_new(&allocated_ptys, NULL, &index);
-	if (idr_ret < 0) {
-		mutex_unlock(&allocated_ptys_lock);
-		if (idr_ret == -EAGAIN)
-			return -ENOMEM;
-		return -EIO;
-	}
-	if (index >= pty_limit) {
-		idr_remove(&allocated_ptys, index);
-		mutex_unlock(&allocated_ptys_lock);
-		return -EIO;
-	}
-	mutex_unlock(&allocated_ptys_lock);
+	index = devpts_new_index();
+	if (index < 0)
+		return index;
 
 	mutex_lock(&tty_mutex);
 	retval = init_dev(ptm_driver, index, &tty);
 	mutex_unlock(&tty_mutex);
-	
+
 	if (retval)
 		goto out;
 
@@ -2767,23 +2812,19 @@ static int ptmx_open(struct inode * inode, struct file * filp)
 	filp->private_data = tty;
 	file_move(filp, &tty->tty_files);
 
-	retval = -ENOMEM;
-	if (devpts_pty_new(tty->link))
+	retval = devpts_pty_new(tty->link);
+	if (retval)
 		goto out1;
 
-	check_tty_count(tty, "tty_open");
-	retval = ptm_driver->open(tty, filp);
-	if (!retval) {
-		tty_audit_opening();
+	check_tty_count(tty, "ptmx_open");
+	retval = ptm_driver->ops->open(tty, filp);
+	if (!retval)
 		return 0;
-	}
 out1:
 	release_dev(filp);
 	return retval;
 out:
-	mutex_lock(&allocated_ptys_lock);
-	idr_remove(&allocated_ptys, index);
-	mutex_unlock(&allocated_ptys_lock);
+	devpts_kill_index(index);
 	return retval;
 }
 #endif
@@ -2800,7 +2841,7 @@ out:
  *		Takes bkl. See release_dev
  */
 
-static int tty_release(struct inode * inode, struct file * filp)
+static int tty_release(struct inode *inode, struct file *filp)
 {
 	lock_kernel();
 	release_dev(filp);
@@ -2820,16 +2861,16 @@ static int tty_release(struct inode * inode, struct file * filp)
  *	may be re-entered freely by other callers.
  */
 
-static unsigned int tty_poll(struct file * filp, poll_table * wait)
+static unsigned int tty_poll(struct file *filp, poll_table *wait)
 {
-	struct tty_struct * tty;
+	struct tty_struct *tty;
 	struct tty_ldisc *ld;
 	int ret = 0;
 
 	tty = (struct tty_struct *)filp->private_data;
 	if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll"))
 		return 0;
-		
+
 	ld = tty_ldisc_ref_wait(tty);
 	if (ld->poll)
 		ret = (ld->poll)(tty, filp, wait);
@@ -2837,15 +2878,16 @@ static unsigned int tty_poll(struct file * filp, poll_table * wait)
 	return ret;
 }
 
-static int tty_fasync(int fd, struct file * filp, int on)
+static int tty_fasync(int fd, struct file *filp, int on)
 {
-	struct tty_struct * tty;
+	struct tty_struct *tty;
+	unsigned long flags;
 	int retval;
 
 	tty = (struct tty_struct *)filp->private_data;
 	if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync"))
 		return 0;
-	
+
 	retval = fasync_helper(fd, filp, on, &tty->fasync);
 	if (retval <= 0)
 		return retval;
@@ -2855,6 +2897,7 @@ static int tty_fasync(int fd, struct file * filp, int on)
 		struct pid *pid;
 		if (!waitqueue_active(&tty->read_wait))
 			tty->minimum_to_wake = 1;
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
 		if (tty->pgrp) {
 			pid = tty->pgrp;
 			type = PIDTYPE_PGID;
@@ -2862,6 +2905,7 @@ static int tty_fasync(int fd, struct file * filp, int on)
 			pid = task_pid(current);
 			type = PIDTYPE_PID;
 		}
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 		retval = __f_setown(filp, pid, type, 0);
 		if (retval)
 			return retval;
@@ -2893,7 +2937,7 @@ static int tiocsti(struct tty_struct *tty, char __user *p)
 {
 	char ch, mbz = 0;
 	struct tty_ldisc *ld;
-	
+
 	if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN))
 		return -EPERM;
 	if (get_user(ch, p))
@@ -2915,7 +2959,7 @@ static int tiocsti(struct tty_struct *tty, char __user *p)
  *		is consistent.
  */
 
-static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg)
+static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
 {
 	int err;
 
@@ -2944,9 +2988,11 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg)
  */
 
 static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty,
-	struct winsize __user * arg)
+	struct winsize __user *arg)
 {
 	struct winsize tmp_ws;
+	struct pid *pgrp, *rpgrp;
+	unsigned long flags;
 
 	if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
 		return -EFAULT;
@@ -2960,14 +3006,25 @@ static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty,
 		if (vc_lock_resize(tty->driver_data, tmp_ws.ws_col,
 					tmp_ws.ws_row)) {
 			mutex_unlock(&tty->termios_mutex);
- 			return -ENXIO;
+			return -ENXIO;
 		}
 	}
 #endif
-	if (tty->pgrp)
-		kill_pgrp(tty->pgrp, SIGWINCH, 1);
-	if ((real_tty->pgrp != tty->pgrp) && real_tty->pgrp)
-		kill_pgrp(real_tty->pgrp, SIGWINCH, 1);
+	/* Get the PID values and reference them so we can
+	   avoid holding the tty ctrl lock while sending signals */
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	pgrp = get_pid(tty->pgrp);
+	rpgrp = get_pid(real_tty->pgrp);
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+	if (pgrp)
+		kill_pgrp(pgrp, SIGWINCH, 1);
+	if (rpgrp != pgrp && rpgrp)
+		kill_pgrp(rpgrp, SIGWINCH, 1);
+
+	put_pid(pgrp);
+	put_pid(rpgrp);
+
 	tty->winsize = tmp_ws;
 	real_tty->winsize = tmp_ws;
 done:
@@ -3028,10 +3085,13 @@ static int fionbio(struct file *file, int __user *p)
 	if (get_user(nonblock, p))
 		return -EFAULT;
 
+	/* file->f_flags is still BKL protected in the fs layer - vomit */
+	lock_kernel();
 	if (nonblock)
 		file->f_flags |= O_NONBLOCK;
 	else
 		file->f_flags &= ~O_NONBLOCK;
+	unlock_kernel();
 	return 0;
 }
 
@@ -3070,7 +3130,7 @@ static int tiocsctty(struct tty_struct *tty, int arg)
 		 * This tty is already the controlling
 		 * tty for another session group!
 		 */
-		if ((arg == 1) && capable(CAP_SYS_ADMIN)) {
+		if (arg == 1 && capable(CAP_SYS_ADMIN)) {
 			/*
 			 * Steal it away
 			 */
@@ -3088,6 +3148,27 @@ unlock:
 	return ret;
 }
 
+/**
+ *	tty_get_pgrp	-	return a ref counted pgrp pid
+ *	@tty: tty to read
+ *
+ *	Returns a refcounted instance of the pid struct for the process
+ *	group controlling the tty.
+ */
+
+struct pid *tty_get_pgrp(struct tty_struct *tty)
+{
+	unsigned long flags;
+	struct pid *pgrp;
+
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	pgrp = get_pid(tty->pgrp);
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+	return pgrp;
+}
+EXPORT_SYMBOL_GPL(tty_get_pgrp);
+
 /**
  *	tiocgpgrp		-	get process group
  *	@tty: tty passed by user
@@ -3102,13 +3183,18 @@ unlock:
 
 static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
 {
+	struct pid *pid;
+	int ret;
 	/*
 	 * (tty == real_tty) is a cheap way of
 	 * testing if the tty is NOT a master pty.
 	 */
 	if (tty == real_tty && current->signal->tty != real_tty)
 		return -ENOTTY;
-	return put_user(pid_vnr(real_tty->pgrp), p);
+	pid = tty_get_pgrp(real_tty);
+	ret =  put_user(pid_vnr(pid), p);
+	put_pid(pid);
+	return ret;
 }
 
 /**
@@ -3120,7 +3206,7 @@ static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
  *	Set the process group of the tty to the session passed. Only
  *	permitted where the tty session is our session.
  *
- *	Locking: None
+ *	Locking: RCU, ctrl lock
  */
 
 static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
@@ -3128,6 +3214,7 @@ static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
 	struct pid *pgrp;
 	pid_t pgrp_nr;
 	int retval = tty_check_change(real_tty);
+	unsigned long flags;
 
 	if (retval == -EIO)
 		return -ENOTTY;
@@ -3150,8 +3237,10 @@ static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
 	if (session_of_pgrp(pgrp) != task_session(current))
 		goto out_unlock;
 	retval = 0;
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
 	put_pid(real_tty->pgrp);
 	real_tty->pgrp = get_pid(pgrp);
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 out_unlock:
 	rcu_read_unlock();
 	return retval;
@@ -3195,10 +3284,16 @@ static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t _
 static int tiocsetd(struct tty_struct *tty, int __user *p)
 {
 	int ldisc;
+	int ret;
 
 	if (get_user(ldisc, p))
 		return -EFAULT;
-	return tty_set_ldisc(tty, ldisc);
+
+	lock_kernel();
+	ret = tty_set_ldisc(tty, ldisc);
+	unlock_kernel();
+
+	return ret;
 }
 
 /**
@@ -3218,18 +3313,18 @@ static int send_break(struct tty_struct *tty, unsigned int duration)
 {
 	if (tty_write_lock(tty, 0) < 0)
 		return -EINTR;
-	tty->driver->break_ctl(tty, -1);
+	tty->ops->break_ctl(tty, -1);
 	if (!signal_pending(current))
 		msleep_interruptible(duration);
-	tty->driver->break_ctl(tty, 0);
+	tty->ops->break_ctl(tty, 0);
 	tty_write_unlock(tty);
-	if (signal_pending(current))
+	if (!signal_pending(current))
 		return -EINTR;
 	return 0;
 }
 
 /**
- *	tiocmget		-	get modem status
+ *	tty_tiocmget		-	get modem status
  *	@tty: tty device
  *	@file: user file pointer
  *	@p: pointer to result
@@ -3244,8 +3339,8 @@ static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p
 {
 	int retval = -EINVAL;
 
-	if (tty->driver->tiocmget) {
-		retval = tty->driver->tiocmget(tty, file);
+	if (tty->ops->tiocmget) {
+		retval = tty->ops->tiocmget(tty, file);
 
 		if (retval >= 0)
 			retval = put_user(retval, p);
@@ -3254,7 +3349,7 @@ static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p
 }
 
 /**
- *	tiocmset		-	set modem status
+ *	tty_tiocmset		-	set modem status
  *	@tty: tty device
  *	@file: user file pointer
  *	@cmd: command - clear bits, set bits or set all
@@ -3271,7 +3366,7 @@ static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int
 {
 	int retval = -EINVAL;
 
-	if (tty->driver->tiocmset) {
+	if (tty->ops->tiocmset) {
 		unsigned int set, clear, val;
 
 		retval = get_user(val, p);
@@ -3295,7 +3390,7 @@ static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int
 		set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
 		clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
 
-		retval = tty->driver->tiocmset(tty, file, set, clear);
+		retval = tty->ops->tiocmset(tty, file, set, clear);
 	}
 	return retval;
 }
@@ -3303,20 +3398,18 @@ static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int
 /*
  * Split this up, as gcc can choke on it otherwise..
  */
-int tty_ioctl(struct inode * inode, struct file * file,
-	      unsigned int cmd, unsigned long arg)
+long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct tty_struct *tty, *real_tty;
 	void __user *p = (void __user *)arg;
 	int retval;
 	struct tty_ldisc *ld;
-	
+	struct inode *inode = file->f_dentry->d_inode;
+
 	tty = (struct tty_struct *)file->private_data;
 	if (tty_paranoia_check(tty, inode, "tty_ioctl"))
 		return -EINVAL;
 
-	/* CHECKME: is this safe as one end closes ? */
-
 	real_tty = tty;
 	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
 	    tty->driver->subtype == PTY_TYPE_MASTER)
@@ -3325,21 +3418,28 @@ int tty_ioctl(struct inode * inode, struct file * file,
 	/*
 	 * Break handling by driver
 	 */
-	if (!tty->driver->break_ctl) {
-		switch(cmd) {
+
+	retval = -EINVAL;
+
+	if (!tty->ops->break_ctl) {
+		switch (cmd) {
 		case TIOCSBRK:
 		case TIOCCBRK:
-			if (tty->driver->ioctl)
-				return tty->driver->ioctl(tty, file, cmd, arg);
-			return -EINVAL;
-			
+			if (tty->ops->ioctl)
+				retval = tty->ops->ioctl(tty, file, cmd, arg);
+			if (retval != -EINVAL && retval != -ENOIOCTLCMD)
+				printk(KERN_WARNING "tty: driver %s needs updating to use break_ctl\n", tty->driver->name);
+			return retval;
+
 		/* These two ioctl's always return success; even if */
 		/* the driver doesn't support them. */
 		case TCSBRK:
 		case TCSBRKP:
-			if (!tty->driver->ioctl)
+			if (!tty->ops->ioctl)
 				return 0;
-			retval = tty->driver->ioctl(tty, file, cmd, arg);
+			retval = tty->ops->ioctl(tty, file, cmd, arg);
+			if (retval != -EINVAL && retval != -ENOIOCTLCMD)
+				printk(KERN_WARNING "tty: driver %s needs updating to use break_ctl\n", tty->driver->name);
 			if (retval == -ENOIOCTLCMD)
 				retval = 0;
 			return retval;
@@ -3354,7 +3454,7 @@ int tty_ioctl(struct inode * inode, struct file * file,
 	case TIOCSBRK:
 	case TIOCCBRK:
 	case TCSBRK:
-	case TCSBRKP:			
+	case TCSBRKP:
 		retval = tty_check_change(tty);
 		if (retval)
 			return retval;
@@ -3367,84 +3467,84 @@ int tty_ioctl(struct inode * inode, struct file * file,
 	}
 
 	switch (cmd) {
-		case TIOCSTI:
-			return tiocsti(tty, p);
-		case TIOCGWINSZ:
-			return tiocgwinsz(tty, p);
-		case TIOCSWINSZ:
-			return tiocswinsz(tty, real_tty, p);
-		case TIOCCONS:
-			return real_tty!=tty ? -EINVAL : tioccons(file);
-		case FIONBIO:
-			return fionbio(file, p);
-		case TIOCEXCL:
-			set_bit(TTY_EXCLUSIVE, &tty->flags);
-			return 0;
-		case TIOCNXCL:
-			clear_bit(TTY_EXCLUSIVE, &tty->flags);
-			return 0;
-		case TIOCNOTTY:
-			if (current->signal->tty != tty)
-				return -ENOTTY;
-			no_tty();
-			return 0;
-		case TIOCSCTTY:
-			return tiocsctty(tty, arg);
-		case TIOCGPGRP:
-			return tiocgpgrp(tty, real_tty, p);
-		case TIOCSPGRP:
-			return tiocspgrp(tty, real_tty, p);
-		case TIOCGSID:
-			return tiocgsid(tty, real_tty, p);
-		case TIOCGETD:
-			/* FIXME: check this is ok */
-			return put_user(tty->ldisc.num, (int __user *)p);
-		case TIOCSETD:
-			return tiocsetd(tty, p);
+	case TIOCSTI:
+		return tiocsti(tty, p);
+	case TIOCGWINSZ:
+		return tiocgwinsz(tty, p);
+	case TIOCSWINSZ:
+		return tiocswinsz(tty, real_tty, p);
+	case TIOCCONS:
+		return real_tty != tty ? -EINVAL : tioccons(file);
+	case FIONBIO:
+		return fionbio(file, p);
+	case TIOCEXCL:
+		set_bit(TTY_EXCLUSIVE, &tty->flags);
+		return 0;
+	case TIOCNXCL:
+		clear_bit(TTY_EXCLUSIVE, &tty->flags);
+		return 0;
+	case TIOCNOTTY:
+		if (current->signal->tty != tty)
+			return -ENOTTY;
+		no_tty();
+		return 0;
+	case TIOCSCTTY:
+		return tiocsctty(tty, arg);
+	case TIOCGPGRP:
+		return tiocgpgrp(tty, real_tty, p);
+	case TIOCSPGRP:
+		return tiocspgrp(tty, real_tty, p);
+	case TIOCGSID:
+		return tiocgsid(tty, real_tty, p);
+	case TIOCGETD:
+		return put_user(tty->ldisc.num, (int __user *)p);
+	case TIOCSETD:
+		return tiocsetd(tty, p);
 #ifdef CONFIG_VT
-		case TIOCLINUX:
-			return tioclinux(tty, arg);
+	case TIOCLINUX:
+		return tioclinux(tty, arg);
 #endif
-		/*
-		 * Break handling
-		 */
-		case TIOCSBRK:	/* Turn break on, unconditionally */
-			tty->driver->break_ctl(tty, -1);
-			return 0;
-			
-		case TIOCCBRK:	/* Turn break off, unconditionally */
-			tty->driver->break_ctl(tty, 0);
-			return 0;
-		case TCSBRK:   /* SVID version: non-zero arg --> no break */
-			/* non-zero arg means wait for all output data
-			 * to be sent (performed above) but don't send break.
-			 * This is used by the tcdrain() termios function.
-			 */
-			if (!arg)
-				return send_break(tty, 250);
-			return 0;
-		case TCSBRKP:	/* support for POSIX tcsendbreak() */	
-			return send_break(tty, arg ? arg*100 : 250);
-
-		case TIOCMGET:
-			return tty_tiocmget(tty, file, p);
+	/*
+	 * Break handling
+	 */
+	case TIOCSBRK:	/* Turn break on, unconditionally */
+		if (tty->ops->break_ctl)
+			tty->ops->break_ctl(tty, -1);
+		return 0;
 
-		case TIOCMSET:
-		case TIOCMBIC:
-		case TIOCMBIS:
-			return tty_tiocmset(tty, file, cmd, p);
-		case TCFLSH:
-			switch (arg) {
-			case TCIFLUSH:
-			case TCIOFLUSH:
-				/* flush tty buffer and allow ldisc to process ioctl */
-				tty_buffer_flush(tty);
-				break;
-			}
+	case TIOCCBRK:	/* Turn break off, unconditionally */
+		if (tty->ops->break_ctl)
+			tty->ops->break_ctl(tty, 0);
+		return 0;
+	case TCSBRK:   /* SVID version: non-zero arg --> no break */
+		/* non-zero arg means wait for all output data
+		 * to be sent (performed above) but don't send break.
+		 * This is used by the tcdrain() termios function.
+		 */
+		if (!arg)
+			return send_break(tty, 250);
+		return 0;
+	case TCSBRKP:	/* support for POSIX tcsendbreak() */
+		return send_break(tty, arg ? arg*100 : 250);
+
+	case TIOCMGET:
+		return tty_tiocmget(tty, file, p);
+	case TIOCMSET:
+	case TIOCMBIC:
+	case TIOCMBIS:
+		return tty_tiocmset(tty, file, cmd, p);
+	case TCFLSH:
+		switch (arg) {
+		case TCIFLUSH:
+		case TCIOFLUSH:
+		/* flush tty buffer and allow ldisc to process ioctl */
+			tty_buffer_flush(tty);
 			break;
+		}
+		break;
 	}
-	if (tty->driver->ioctl) {
-		retval = (tty->driver->ioctl)(tty, file, cmd, arg);
+	if (tty->ops->ioctl) {
+		retval = (tty->ops->ioctl)(tty, file, cmd, arg);
 		if (retval != -ENOIOCTLCMD)
 			return retval;
 	}
@@ -3460,7 +3560,7 @@ int tty_ioctl(struct inode * inode, struct file * file,
 }
 
 #ifdef CONFIG_COMPAT
-static long tty_compat_ioctl(struct file * file, unsigned int cmd,
+static long tty_compat_ioctl(struct file *file, unsigned int cmd,
 				unsigned long arg)
 {
 	struct inode *inode = file->f_dentry->d_inode;
@@ -3471,8 +3571,8 @@ static long tty_compat_ioctl(struct file * file, unsigned int cmd,
 	if (tty_paranoia_check(tty, inode, "tty_ioctl"))
 		return -EINVAL;
 
-	if (tty->driver->compat_ioctl) {
-		retval = (tty->driver->compat_ioctl)(tty, file, cmd, arg);
+	if (tty->ops->compat_ioctl) {
+		retval = (tty->ops->compat_ioctl)(tty, file, cmd, arg);
 		if (retval != -ENOIOCTLCMD)
 			return retval;
 	}
@@ -3491,7 +3591,7 @@ static long tty_compat_ioctl(struct file * file, unsigned int cmd,
  * prevent trojan horses by killing all processes associated with this
  * tty when the user hits the "Secure Attention Key".  Required for
  * super-paranoid applications --- see the Orange Book for more details.
- * 
+ *
  * This code could be nicer; ideally it should send a HUP, wait a few
  * seconds, then send a INT, and then a KILL signal.  But you then
  * have to coordinate with the init process, since all processes associated
@@ -3515,16 +3615,15 @@ void __do_SAK(struct tty_struct *tty)
 	int		i;
 	struct file	*filp;
 	struct fdtable *fdt;
-	
+
 	if (!tty)
 		return;
 	session = tty->session;
-	
+
 	tty_ldisc_flush(tty);
 
-	if (tty->driver->flush_buffer)
-		tty->driver->flush_buffer(tty);
-	
+	tty_driver_flush_buffer(tty);
+
 	read_lock(&tasklist_lock);
 	/* Kill the entire session */
 	do_each_pid_task(session, PIDTYPE_SID, p) {
@@ -3552,7 +3651,7 @@ void __do_SAK(struct tty_struct *tty)
 			 */
 			spin_lock(&p->files->file_lock);
 			fdt = files_fdtable(p->files);
-			for (i=0; i < fdt->max_fds; i++) {
+			for (i = 0; i < fdt->max_fds; i++) {
 				filp = fcheck_files(p->files, i);
 				if (!filp)
 					continue;
@@ -3606,7 +3705,7 @@ EXPORT_SYMBOL(do_SAK);
  *	while invoking the line discipline receive_buf method. The
  *	receive_buf method is single threaded for each tty instance.
  */
- 
+
 static void flush_to_ldisc(struct work_struct *work)
 {
 	struct tty_struct *tty =
@@ -3622,7 +3721,8 @@ static void flush_to_ldisc(struct work_struct *work)
 		return;
 
 	spin_lock_irqsave(&tty->buf.lock, flags);
-	set_bit(TTY_FLUSHING, &tty->flags);	/* So we know a flush is running */
+	/* So we know a flush is running */
+	set_bit(TTY_FLUSHING, &tty->flags);
 	head = tty->buf.head;
 	if (head != NULL) {
 		tty->buf.head = NULL;
@@ -3728,19 +3828,32 @@ static void initialize_tty_struct(struct tty_struct *tty)
 	mutex_init(&tty->atomic_read_lock);
 	mutex_init(&tty->atomic_write_lock);
 	spin_lock_init(&tty->read_lock);
+	spin_lock_init(&tty->ctrl_lock);
 	INIT_LIST_HEAD(&tty->tty_files);
 	INIT_WORK(&tty->SAK_work, do_SAK_work);
 }
 
-/*
- * The default put_char routine if the driver did not define one.
+/**
+ *	tty_put_char	-	write one character to a tty
+ *	@tty: tty
+ *	@ch: character
+ *
+ *	Write one byte to the tty using the provided put_char method
+ *	if present. Returns the number of characters successfully output.
+ *
+ *	Note: the specific put_char operation in the driver layer may go
+ *	away soon. Don't call it directly, use this method
  */
 
-static void tty_default_put_char(struct tty_struct *tty, unsigned char ch)
+int tty_put_char(struct tty_struct *tty, unsigned char ch)
 {
-	tty->driver->write(tty, &ch, 1);
+	if (tty->ops->put_char)
+		return tty->ops->put_char(tty, ch);
+	return tty->ops->write(tty, &ch, 1);
 }
 
+EXPORT_SYMBOL_GPL(tty_put_char);
+
 static struct class *tty_class;
 
 /**
@@ -3795,7 +3908,8 @@ struct device *tty_register_device(struct tty_driver *driver, unsigned index,
 
 void tty_unregister_device(struct tty_driver *driver, unsigned index)
 {
-	device_destroy(tty_class, MKDEV(driver->major, driver->minor_start) + index);
+	device_destroy(tty_class,
+		MKDEV(driver->major, driver->minor_start) + index);
 }
 
 EXPORT_SYMBOL(tty_register_device);
@@ -3822,32 +3936,8 @@ void put_tty_driver(struct tty_driver *driver)
 void tty_set_operations(struct tty_driver *driver,
 			const struct tty_operations *op)
 {
-	driver->open = op->open;
-	driver->close = op->close;
-	driver->write = op->write;
-	driver->put_char = op->put_char;
-	driver->flush_chars = op->flush_chars;
-	driver->write_room = op->write_room;
-	driver->chars_in_buffer = op->chars_in_buffer;
-	driver->ioctl = op->ioctl;
-	driver->compat_ioctl = op->compat_ioctl;
-	driver->set_termios = op->set_termios;
-	driver->throttle = op->throttle;
-	driver->unthrottle = op->unthrottle;
-	driver->stop = op->stop;
-	driver->start = op->start;
-	driver->hangup = op->hangup;
-	driver->break_ctl = op->break_ctl;
-	driver->flush_buffer = op->flush_buffer;
-	driver->set_ldisc = op->set_ldisc;
-	driver->wait_until_sent = op->wait_until_sent;
-	driver->send_xchar = op->send_xchar;
-	driver->read_proc = op->read_proc;
-	driver->write_proc = op->write_proc;
-	driver->tiocmget = op->tiocmget;
-	driver->tiocmset = op->tiocmset;
-}
-
+	driver->ops = op;
+};
 
 EXPORT_SYMBOL(alloc_tty_driver);
 EXPORT_SYMBOL(put_tty_driver);
@@ -3859,7 +3949,7 @@ EXPORT_SYMBOL(tty_set_operations);
 int tty_register_driver(struct tty_driver *driver)
 {
 	int error;
-        int i;
+	int i;
 	dev_t dev;
 	void **p = NULL;
 
@@ -3873,8 +3963,8 @@ int tty_register_driver(struct tty_driver *driver)
 	}
 
 	if (!driver->major) {
-		error = alloc_chrdev_region(&dev, driver->minor_start, driver->num,
-						driver->name);
+		error = alloc_chrdev_region(&dev, driver->minor_start,
+						driver->num, driver->name);
 		if (!error) {
 			driver->major = MAJOR(dev);
 			driver->minor_start = MINOR(dev);
@@ -3891,7 +3981,8 @@ int tty_register_driver(struct tty_driver *driver)
 	if (p) {
 		driver->ttys = (struct tty_struct **)p;
 		driver->termios = (struct ktermios **)(p + driver->num);
-		driver->termios_locked = (struct ktermios **)(p + driver->num * 2);
+		driver->termios_locked = (struct ktermios **)
+							(p + driver->num * 2);
 	} else {
 		driver->ttys = NULL;
 		driver->termios = NULL;
@@ -3909,15 +4000,12 @@ int tty_register_driver(struct tty_driver *driver)
 		return error;
 	}
 
-	if (!driver->put_char)
-		driver->put_char = tty_default_put_char;
-	
 	mutex_lock(&tty_mutex);
 	list_add(&driver->tty_drivers, &tty_drivers);
 	mutex_unlock(&tty_mutex);
-	
-	if ( !(driver->flags & TTY_DRIVER_DYNAMIC_DEV) ) {
-		for(i = 0; i < driver->num; i++)
+
+	if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) {
+		for (i = 0; i < driver->num; i++)
 		    tty_register_device(driver, i, NULL);
 	}
 	proc_tty_register_driver(driver);
@@ -3987,14 +4075,19 @@ void proc_clear_tty(struct task_struct *p)
 }
 EXPORT_SYMBOL(proc_clear_tty);
 
+/* Called under the sighand lock */
+
 static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
 {
 	if (tty) {
-		/* We should not have a session or pgrp to here but.... */
+		unsigned long flags;
+		/* We should not have a session or pgrp to put here but.... */
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
 		put_pid(tty->session);
 		put_pid(tty->pgrp);
-		tty->session = get_pid(task_session(tsk));
 		tty->pgrp = get_pid(task_pgrp(tsk));
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+		tty->session = get_pid(task_session(tsk));
 	}
 	put_pid(tsk->signal->tty_old_pgrp);
 	tsk->signal->tty = tty;
@@ -4037,7 +4130,7 @@ void __init console_init(void)
 	(void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
 
 	/*
-	 * set up the console device so that later boot sequences can 
+	 * set up the console device so that later boot sequences can
 	 * inform about problems etc..
 	 */
 	call = __con_initcall_start;