Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 2980 insertions, 0 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
new file mode 100644
index 0000000..06e5a3f
--- /dev/null
+++ b/drivers/char/tty_io.c
@@ -0,0 +1,2980 @@
+/*
+ *  linux/drivers/char/tty_io.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+/*
+ * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
+ * or rs-channels. It also implements echoing, cooked mode etc.
+ *
+ * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
+ *
+ * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
+ * tty_struct and tty_queue structures.  Previously there was an array
+ * of 256 tty_struct's which was statically allocated, and the
+ * tty_queue structures were allocated at boot time.  Both are now
+ * dynamically allocated only when the tty is open.
+ *
+ * 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 
+ *
+ * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
+ * which can be dynamically activated and de-activated by the line
+ * discipline handling modules (like SLIP).
+ *
+ * NOTE: pay no attention to the line discipline code (yet); its
+ * interface is still subject to change in this version...
+ * -- TYT, 1/31/92
+ *
+ * Added functionality to the OPOST tty handling.  No delays, but all
+ * other bits should be there.
+ *	-- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993.
+ *
+ * Rewrote canonical mode and added more termios flags.
+ * 	-- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94
+ *
+ * Reorganized FASYNC support so mouse code can share it.
+ *	-- ctm@ardi.com, 9Sep95
+ *
+ * New TIOCLINUX variants added.
+ *	-- mj@k332.feld.cvut.cz, 19-Nov-95
+ * 
+ * Restrict vt switching via ioctl()
+ *      -- grif@cs.ucr.edu, 5-Dec-95
+ *
+ * Move console and virtual terminal code to more appropriate files,
+ * implement CONFIG_VT and generalize console device interface.
+ *	-- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
+ *
+ * Rewrote init_dev and release_dev to eliminate races.
+ *	-- Bill Hawes <whawes@star.net>, June 97
+ *
+ * Added devfs support.
+ *      -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998
+ *
+ * Added support for a Unix98-style ptmx device.
+ *      -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
+ *
+ * Reduced memory usage for older ARM systems
+ *      -- 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
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/major.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/fcntl.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/devpts_fs.h>
+#include <linux/file.h>
+#include <linux/console.h>
+#include <linux/timer.h>
+#include <linux/ctype.h>
+#include <linux/kd.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#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 <asm/uaccess.h>
+#include <asm/system.h>
+
+#include <linux/kbd_kern.h>
+#include <linux/vt_kern.h>
+#include <linux/selection.h>
+#include <linux/devfs_fs_kernel.h>
+
+#include <linux/kmod.h>
+
+#undef TTY_DEBUG_HANGUP
+
+#define TTY_PARANOIA_CHECK 1
+#define CHECK_TTY_COUNT 1
+
+struct termios tty_std_termios = {	/* for the benefit of tty drivers  */
+	.c_iflag = ICRNL | IXON,
+	.c_oflag = OPOST | ONLCR,
+	.c_cflag = B38400 | CS8 | CREAD | HUPCL,
+	.c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK |
+		   ECHOCTL | ECHOKE | IEXTEN,
+	.c_cc = INIT_C_CC
+};
+
+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 */
+
+/* Semaphore to protect creating and releasing a tty. This is shared with
+   vt.c for deeply disgusting hack reasons */
+DECLARE_MUTEX(tty_sem);
+
+#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 DECLARE_MUTEX(allocated_ptys_lock);
+static int ptmx_open(struct inode *, struct file *);
+#endif
+
+extern void disable_early_printk(void);
+
+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 *);
+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);
+static int tty_fasync(int fd, struct file * filp, int on);
+extern void rs_360_init(void);
+static void release_mem(struct tty_struct *tty, int idx);
+
+
+static struct tty_struct *alloc_tty_struct(void)
+{
+	struct tty_struct *tty;
+
+	tty = kmalloc(sizeof(struct tty_struct), GFP_KERNEL);
+	if (tty)
+		memset(tty, 0, sizeof(struct tty_struct));
+	return tty;
+}
+
+static inline void free_tty_struct(struct tty_struct *tty)
+{
+	kfree(tty->write_buf);
+	kfree(tty);
+}
+
+#define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
+
+char *tty_name(struct tty_struct *tty, char *buf)
+{
+	if (!tty) /* Hmm.  NULL pointer.  That's fun. */
+		strcpy(buf, "NULL tty");
+	else
+		strcpy(buf, tty->name);
+	return buf;
+}
+
+EXPORT_SYMBOL(tty_name);
+
+inline int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
+			      const char *routine)
+{
+#ifdef TTY_PARANOIA_CHECK
+	if (!tty) {
+		printk(KERN_WARNING
+			"null TTY for (%d:%d) in %s\n",
+			imajor(inode), iminor(inode), routine);
+		return 1;
+	}
+	if (tty->magic != TTY_MAGIC) {
+		printk(KERN_WARNING
+			"bad magic number for tty struct (%d:%d) in %s\n",
+			imajor(inode), iminor(inode), routine);
+		return 1;
+	}
+#endif
+	return 0;
+}
+
+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++;
+	}
+	file_list_unlock();
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_SLAVE &&
+	    tty->link && tty->link->count)
+		count++;
+	if (tty->count != count) {
+		printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) "
+				    "!= #fd's(%d) in %s\n",
+		       tty->name, tty->count, count, routine);
+		return count;
+       }	
+#endif
+	return 0;
+}
+
+/*
+ *	This is probably overkill for real world processors but
+ *	they are not on hot paths so a little discipline won't do 
+ *	any harm.
+ */
+ 
+static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
+{
+	down(&tty->termios_sem);
+	tty->termios->c_line = num;
+	up(&tty->termios_sem);
+}
+
+/*
+ *	This guards the refcounted line discipline lists. The lock
+ *	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	*/
+
+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);
+	if (new_ldisc) {
+		tty_ldiscs[disc] = *new_ldisc;
+		tty_ldiscs[disc].num = disc;
+		tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED;
+		tty_ldiscs[disc].refcount = 0;
+	} else {
+		if(tty_ldiscs[disc].refcount)
+			ret = -EBUSY;
+		else
+			tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED;
+	}
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+	
+	return ret;
+}
+
+EXPORT_SYMBOL(tty_register_ldisc);
+
+struct tty_ldisc *tty_ldisc_get(int disc)
+{
+	unsigned long flags;
+	struct tty_ldisc *ld;
+
+	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 the module is being unloaded we can't use it */
+		if (!try_module_get(ld->owner))
+		       	ld = NULL;
+		else /* lock it */
+			ld->refcount++;
+	}
+	else
+		ld = NULL;
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+	return ld;
+}
+
+EXPORT_SYMBOL_GPL(tty_ldisc_get);
+
+void tty_ldisc_put(int disc)
+{
+	struct tty_ldisc *ld;
+	unsigned long flags;
+	
+	if (disc < N_TTY || disc >= NR_LDISCS)
+		BUG();
+		
+	spin_lock_irqsave(&tty_ldisc_lock, flags);
+	ld = &tty_ldiscs[disc];
+	if(ld->refcount == 0)
+		BUG();
+	ld->refcount --;
+	module_put(ld->owner);
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+}
+	
+EXPORT_SYMBOL_GPL(tty_ldisc_put);
+
+static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld)
+{
+	tty->ldisc = *ld;
+	tty->ldisc.refcount = 0;
+}
+
+/**
+ *	tty_ldisc_try		-	internal helper
+ *	@tty: the tty
+ *
+ *	Make a single attempt to grab and bump the refcount on
+ *	the tty ldisc. Return 0 on failure or 1 on success. This is
+ *	used to implement both the waiting and non waiting versions
+ *	of tty_ldisc_ref
+ */
+
+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))
+	{
+		ld->refcount++;
+		ret = 1;
+	}
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+	return ret;
+}
+
+/**
+ *	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 
+ *	wait patiently until it changes.
+ *
+ *	Note: Must not be called from an IRQ/timer context. The caller
+ *	must also be careful not to hold other locks that will deadlock
+ *	against a discipline change, such as an existing ldisc reference
+ *	(which we check for)
+ */
+ 
+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)
+		printk(KERN_ERR "tty_ldisc_ref_wait\n");
+	return &tty->ldisc;
+}
+
+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 
+ *	return NULL. Can be called from IRQ and timer functions.
+ */
+ 
+struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty)
+{
+	if(tty_ldisc_try(tty))
+		return &tty->ldisc;
+	return NULL;
+}
+
+EXPORT_SYMBOL_GPL(tty_ldisc_ref);
+
+/**
+ *	tty_ldisc_deref		-	free a tty ldisc reference
+ *	@ld: reference to free up
+ *
+ *	Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May
+ *	be called in IRQ context.
+ */
+ 
+void tty_ldisc_deref(struct tty_ldisc *ld)
+{
+	unsigned long flags;
+
+	if(ld == NULL)
+		BUG();
+		
+	spin_lock_irqsave(&tty_ldisc_lock, flags);
+	if(ld->refcount == 0)
+		printk(KERN_ERR "tty_ldisc_deref: no references.\n");
+	else
+		ld->refcount--;
+	if(ld->refcount == 0)
+		wake_up(&tty_ldisc_wait);
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+}
+
+EXPORT_SYMBOL_GPL(tty_ldisc_deref);
+
+/**
+ *	tty_ldisc_enable	-	allow ldisc use
+ *	@tty: terminal to activate ldisc on
+ *
+ *	Set the TTY_LDISC flag when the line discipline can be called
+ *	again. Do neccessary wakeups for existing sleepers.
+ *
+ *	Note: nobody should set this bit except via this function. Clearing
+ *	directly is allowed.
+ */
+
+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
+ *	@ldisc: the line discipline
+ *
+ *	Set the discipline of a tty line. Must be called from a process
+ *	context.
+ */
+ 
+static int tty_set_ldisc(struct tty_struct *tty, int ldisc)
+{
+	int	retval = 0;
+	struct	tty_ldisc o_ldisc;
+	char buf[64];
+	int work;
+	unsigned long flags;
+	struct tty_ldisc *ld;
+
+	if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS))
+		return -EINVAL;
+
+restart:
+
+	if (tty->ldisc.num == ldisc)
+		return 0;	/* We are already in the desired discipline */
+	
+	ld = tty_ldisc_get(ldisc);
+	/* Eduardo Blanco <ejbs@cs.cs.com.uy> */
+	/* Cyrus Durgin <cider@speakeasy.org> */
+	if (ld == NULL) {
+		request_module("tty-ldisc-%d", ldisc);
+		ld = tty_ldisc_get(ldisc);
+	}
+	if (ld == NULL)
+		return -EINVAL;
+
+	o_ldisc = tty->ldisc;
+
+	tty_wait_until_sent(tty, 0);
+
+	/*
+	 *	Make sure we don't change while someone holds a
+	 *	reference to the line discipline. The TTY_LDISC bit
+	 *	prevents anyone taking a reference once it is clear.
+	 *	We need the lock to avoid racing reference takers.
+	 */
+	 
+	spin_lock_irqsave(&tty_ldisc_lock, flags);
+	if(tty->ldisc.refcount)
+	{
+		/* Free the new ldisc we grabbed. Must drop the lock
+		   first. */
+		spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+		tty_ldisc_put(ldisc);
+		/*
+		 * 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.
+		 */
+		if(wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0)
+			return -ERESTARTSYS;			
+		goto restart;
+	}
+	clear_bit(TTY_LDISC, &tty->flags);	
+	clear_bit(TTY_DONT_FLIP, &tty->flags);
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+	
+	/*
+	 *	From this point on we know nobody has an ldisc
+	 *	usage reference, nor can they obtain one until
+	 *	we say so later on.
+	 */
+	 
+	work = cancel_delayed_work(&tty->flip.work);
+	/*
+	 * Wait for ->hangup_work and ->flip.work handlers to terminate
+	 */
+	 
+	flush_scheduled_work();
+	/* Shutdown the current discipline. */
+	if (tty->ldisc.close)
+		(tty->ldisc.close)(tty);
+
+	/* Now set up the new line discipline. */
+	tty_ldisc_assign(tty, ld);
+	tty_set_termios_ldisc(tty, ldisc);
+	if (tty->ldisc.open)
+		retval = (tty->ldisc.open)(tty);
+	if (retval < 0) {
+		tty_ldisc_put(ldisc);
+		/* There is an outstanding reference here so this is safe */
+		tty_ldisc_assign(tty, tty_ldisc_get(o_ldisc.num));
+		tty_set_termios_ldisc(tty, tty->ldisc.num);
+		if (tty->ldisc.open && (tty->ldisc.open(tty) < 0)) {
+			tty_ldisc_put(o_ldisc.num);
+			/* This driver is always present */
+			tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
+			tty_set_termios_ldisc(tty, N_TTY);
+			if (tty->ldisc.open) {
+				int r = tty->ldisc.open(tty);
+
+				if (r < 0)
+					panic("Couldn't open N_TTY ldisc for "
+					      "%s --- error %d.",
+					      tty_name(tty, buf), r);
+			}
+		}
+	}
+	/* 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);
+		
+	tty_ldisc_put(o_ldisc.num);
+	
+	/*
+	 *	Allow ldisc referencing to occur as soon as the driver
+	 *	ldisc callback completes.
+	 */
+	 
+	tty_ldisc_enable(tty);
+	
+	/* Restart it in case no characters kick it off. Safe if
+	   already running */
+	if(work)
+		schedule_delayed_work(&tty->flip.work, 1);
+	return retval;
+}
+
+/*
+ * This routine returns a tty driver structure, given a device number
+ */
+static struct tty_driver *get_tty_driver(dev_t device, int *index)
+{
+	struct tty_driver *p;
+
+	list_for_each_entry(p, &tty_drivers, tty_drivers) {
+		dev_t base = MKDEV(p->major, p->minor_start);
+		if (device < base || device >= base + p->num)
+			continue;
+		*index = device - base;
+		return p;
+	}
+	return NULL;
+}
+
+/*
+ * If we try to write to, or set the state of, a terminal and we're
+ * not in the foreground, send a SIGTTOU.  If the signal is blocked or
+ * ignored, go ahead and perform the operation.  (POSIX 7.2)
+ */
+int tty_check_change(struct tty_struct * tty)
+{
+	if (current->signal->tty != tty)
+		return 0;
+	if (tty->pgrp <= 0) {
+		printk(KERN_WARNING "tty_check_change: tty->pgrp <= 0!\n");
+		return 0;
+	}
+	if (process_group(current) == tty->pgrp)
+		return 0;
+	if (is_ignored(SIGTTOU))
+		return 0;
+	if (is_orphaned_pgrp(process_group(current)))
+		return -EIO;
+	(void) kill_pg(process_group(current), SIGTTOU, 1);
+	return -ERESTARTSYS;
+}
+
+EXPORT_SYMBOL(tty_check_change);
+
+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,
+				 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)
+{
+	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)
+{
+	return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
+}
+
+static struct file_operations tty_fops = {
+	.llseek		= no_llseek,
+	.read		= tty_read,
+	.write		= tty_write,
+	.poll		= tty_poll,
+	.ioctl		= tty_ioctl,
+	.open		= tty_open,
+	.release	= tty_release,
+	.fasync		= tty_fasync,
+};
+
+#ifdef CONFIG_UNIX98_PTYS
+static struct file_operations ptmx_fops = {
+	.llseek		= no_llseek,
+	.read		= tty_read,
+	.write		= tty_write,
+	.poll		= tty_poll,
+	.ioctl		= tty_ioctl,
+	.open		= ptmx_open,
+	.release	= tty_release,
+	.fasync		= tty_fasync,
+};
+#endif
+
+static struct file_operations console_fops = {
+	.llseek		= no_llseek,
+	.read		= tty_read,
+	.write		= redirected_tty_write,
+	.poll		= tty_poll,
+	.ioctl		= tty_ioctl,
+	.open		= tty_open,
+	.release	= tty_release,
+	.fasync		= tty_fasync,
+};
+
+static struct file_operations hung_up_tty_fops = {
+	.llseek		= no_llseek,
+	.read		= hung_up_tty_read,
+	.write		= hung_up_tty_write,
+	.poll		= hung_up_tty_poll,
+	.ioctl		= hung_up_tty_ioctl,
+	.release	= tty_release,
+};
+
+static DEFINE_SPINLOCK(redirect_lock);
+static struct file *redirect;
+
+/**
+ *	tty_wakeup	-	request more data
+ *	@tty: terminal
+ *
+ *	Internal and external helper for wakeups of tty. This function
+ *	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)
+				ld->write_wakeup(tty);
+			tty_ldisc_deref(ld);
+		}
+	}
+	wake_up_interruptible(&tty->write_wait);
+}
+
+EXPORT_SYMBOL_GPL(tty_wakeup);
+
+/**
+ *	tty_ldisc_flush	-	flush line discipline queue
+ *	@tty: tty
+ *
+ *	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)
+			ld->flush_buffer(tty);
+		tty_ldisc_deref(ld);
+	}
+}
+
+EXPORT_SYMBOL_GPL(tty_ldisc_flush);
+	
+/*
+ * This can be called by the "eventd" kernel thread.  That is process synchronous,
+ * but doesn't hold any locks, so we need to make sure we have the appropriate
+ * locks for what we're doing..
+ */
+static void do_tty_hangup(void *data)
+{
+	struct tty_struct *tty = (struct tty_struct *) data;
+	struct file * cons_filp = NULL;
+	struct file *filp, *f = NULL;
+	struct task_struct *p;
+	struct tty_ldisc *ld;
+	int    closecount = 0, n;
+
+	if (!tty)
+		return;
+
+	/* inuse_filps is protected by the single kernel lock */
+	lock_kernel();
+
+	spin_lock(&redirect_lock);
+	if (redirect && redirect->private_data == tty) {
+		f = redirect;
+		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 ? */
+	list_for_each_entry(filp, &tty->tty_files, f_list) {
+		if (filp->f_op->write == redirected_tty_write)
+			cons_filp = filp;
+		if (filp->f_op->write != tty_write)
+			continue;
+		closecount++;
+		tty_fasync(-1, filp, 0);	/* can't block */
+		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. */
+
+	ld = tty_ldisc_ref(tty);
+	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);
+		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 */
+	   
+	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)
+	{
+		down(&tty->termios_sem);
+		*tty->termios = tty->driver->init_termios;
+		up(&tty->termios_sem);
+	}
+	
+	/* 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 > 0) {
+		do_each_task_pid(tty->session, PIDTYPE_SID, p) {
+			if (p->signal->tty == tty)
+				p->signal->tty = NULL;
+			if (!p->signal->leader)
+				continue;
+			send_group_sig_info(SIGHUP, SEND_SIG_PRIV, p);
+			send_group_sig_info(SIGCONT, SEND_SIG_PRIV, p);
+			if (tty->pgrp > 0)
+				p->signal->tty_old_pgrp = tty->pgrp;
+		} while_each_task_pid(tty->session, PIDTYPE_SID, p);
+	}
+	read_unlock(&tasklist_lock);
+
+	tty->flags = 0;
+	tty->session = 0;
+	tty->pgrp = -1;
+	tty->ctrl_status = 0;
+	/*
+	 *	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)
+			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 */
+
+	set_bit(TTY_HUPPED, &tty->flags);
+	if (ld) {
+		tty_ldisc_enable(tty);
+		tty_ldisc_deref(ld);
+	}
+	unlock_kernel();
+	if (f)
+		fput(f);
+}
+
+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);
+}
+
+EXPORT_SYMBOL(tty_hangup);
+
+void tty_vhangup(struct tty_struct * tty)
+{
+#ifdef TTY_DEBUG_HANGUP
+	char	buf[64];
+
+	printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf));
+#endif
+	do_tty_hangup((void *) tty);
+}
+EXPORT_SYMBOL(tty_vhangup);
+
+int tty_hung_up_p(struct file * filp)
+{
+	return (filp->f_op == &hung_up_tty_fops);
+}
+
+EXPORT_SYMBOL(tty_hung_up_p);
+
+/*
+ * This function is typically called only by the session leader, when
+ * it wants to disassociate itself from its controlling tty.
+ *
+ * It performs the following functions:
+ * 	(1)  Sends a SIGHUP and SIGCONT to the foreground process group
+ * 	(2)  Clears the tty from being controlling the session
+ * 	(3)  Clears the controlling tty for all processes in the
+ * 		session group.
+ *
+ * The argument on_exit is set to 1 if called when a process is
+ * exiting; it is 0 if called by the ioctl TIOCNOTTY.
+ */
+void disassociate_ctty(int on_exit)
+{
+	struct tty_struct *tty;
+	struct task_struct *p;
+	int tty_pgrp = -1;
+
+	lock_kernel();
+
+	down(&tty_sem);
+	tty = current->signal->tty;
+	if (tty) {
+		tty_pgrp = tty->pgrp;
+		up(&tty_sem);
+		if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY)
+			tty_vhangup(tty);
+	} else {
+		if (current->signal->tty_old_pgrp) {
+			kill_pg(current->signal->tty_old_pgrp, SIGHUP, on_exit);
+			kill_pg(current->signal->tty_old_pgrp, SIGCONT, on_exit);
+		}
+		up(&tty_sem);
+		unlock_kernel();	
+		return;
+	}
+	if (tty_pgrp > 0) {
+		kill_pg(tty_pgrp, SIGHUP, on_exit);
+		if (!on_exit)
+			kill_pg(tty_pgrp, SIGCONT, on_exit);
+	}
+
+	/* Must lock changes to tty_old_pgrp */
+	down(&tty_sem);
+	current->signal->tty_old_pgrp = 0;
+	tty->session = 0;
+	tty->pgrp = -1;
+
+	/* Now clear signal->tty under the lock */
+	read_lock(&tasklist_lock);
+	do_each_task_pid(current->signal->session, PIDTYPE_SID, p) {
+		p->signal->tty = NULL;
+	} while_each_task_pid(current->signal->session, PIDTYPE_SID, p);
+	read_unlock(&tasklist_lock);
+	up(&tty_sem);
+	unlock_kernel();
+}
+
+void stop_tty(struct tty_struct *tty)
+{
+	if (tty->stopped)
+		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);
+}
+
+EXPORT_SYMBOL(stop_tty);
+
+void start_tty(struct tty_struct *tty)
+{
+	if (!tty->stopped || tty->flow_stopped)
+		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);
+
+	/* If we have a running line discipline it may need kicking */
+	tty_wakeup(tty);
+	wake_up_interruptible(&tty->write_wait);
+}
+
+EXPORT_SYMBOL(start_tty);
+
+static ssize_t tty_read(struct file * file, char __user * buf, size_t count, 
+			loff_t *ppos)
+{
+	int i;
+	struct tty_struct * tty;
+	struct inode *inode;
+	struct tty_ldisc *ld;
+
+	tty = (struct tty_struct *)file->private_data;
+	inode = file->f_dentry->d_inode;
+	if (tty_paranoia_check(tty, inode, "tty_read"))
+		return -EIO;
+	if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags)))
+		return -EIO;
+
+	/* 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);
+	else
+		i = -EIO;
+	tty_ldisc_deref(ld);
+	unlock_kernel();
+	if (i > 0)
+		inode->i_atime = current_fs_time(inode->i_sb);
+	return i;
+}
+
+/*
+ * Split writes up in sane blocksizes to avoid
+ * denial-of-service type attacks
+ */
+static inline ssize_t do_tty_write(
+	ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t),
+	struct tty_struct *tty,
+	struct file *file,
+	const char __user *buf,
+	size_t count)
+{
+	ssize_t ret = 0, written = 0;
+	unsigned int chunk;
+	
+	if (down_interruptible(&tty->atomic_write)) {
+		return -ERESTARTSYS;
+	}
+
+	/*
+	 * We chunk up writes into a temporary buffer. This
+	 * simplifies low-level drivers immensely, since they
+	 * don't have locking issues and user mode accesses.
+	 *
+	 * But if TTY_NO_WRITE_SPLIT is set, we should use a
+	 * big chunk-size..
+	 *
+	 * The default chunk-size is 2kB, because the NTTY
+	 * layer has problems with bigger chunks. It will
+	 * claim to be able to handle more characters than
+	 * it actually does.
+	 */
+	chunk = 2048;
+	if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags))
+		chunk = 65536;
+	if (count < chunk)
+		chunk = count;
+
+	/* write_buf/write_cnt is protected by the atomic_write semaphore */
+	if (tty->write_cnt < chunk) {
+		unsigned char *buf;
+
+		if (chunk < 1024)
+			chunk = 1024;
+
+		buf = kmalloc(chunk, GFP_KERNEL);
+		if (!buf) {
+			up(&tty->atomic_write);
+			return -ENOMEM;
+		}
+		kfree(tty->write_buf);
+		tty->write_cnt = chunk;
+		tty->write_buf = buf;
+	}
+
+	/* Do the write .. */
+	for (;;) {
+		size_t size = count;
+		if (size > chunk)
+			size = chunk;
+		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;
+		buf += ret;
+		count -= ret;
+		if (!count)
+			break;
+		ret = -ERESTARTSYS;
+		if (signal_pending(current))
+			break;
+		cond_resched();
+	}
+	if (written) {
+		struct inode *inode = file->f_dentry->d_inode;
+		inode->i_mtime = current_fs_time(inode->i_sb);
+		ret = written;
+	}
+	up(&tty->atomic_write);
+	return ret;
+}
+
+
+static ssize_t tty_write(struct file * file, const char __user * buf, size_t count,
+			 loff_t *ppos)
+{
+	struct tty_struct * tty;
+	struct inode *inode = file->f_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 (!ld->write)
+		ret = -EIO;
+	else
+		ret = do_tty_write(ld->write, tty, file, buf, count);
+	tty_ldisc_deref(ld);
+	return ret;
+}
+
+ssize_t redirected_tty_write(struct file * file, const char __user * buf, size_t count,
+			 loff_t *ppos)
+{
+	struct file *p = NULL;
+
+	spin_lock(&redirect_lock);
+	if (redirect) {
+		get_file(redirect);
+		p = redirect;
+	}
+	spin_unlock(&redirect_lock);
+
+	if (p) {
+		ssize_t res;
+		res = vfs_write(p, buf, count, &p->f_pos);
+		fput(p);
+		return res;
+	}
+
+	return tty_write(file, buf, count, ppos);
+}
+
+static char ptychar[] = "pqrstuvwxyzabcde";
+
+static inline 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);
+}
+
+static inline void tty_line_name(struct tty_driver *driver, int index, char *p)
+{
+	sprintf(p, "%s%d", driver->name, index + driver->name_base);
+}
+
+/*
+ * WSH 06/09/97: Rewritten to remove races and properly clean up after a
+ * failed open.  The new code protects the open with a semaphore, so it's
+ * really quite straightforward.  The semaphore locking can probably be
+ * relaxed for the (most common) case of reopening a tty.
+ */
+static int init_dev(struct tty_driver *driver, int idx,
+	struct tty_struct **ret_tty)
+{
+	struct tty_struct *tty, *o_tty;
+	struct termios *tp, **tp_loc, *o_tp, **o_tp_loc;
+	struct termios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc;
+	int retval=0;
+
+	/* check whether we're reopening an existing tty */
+	if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
+		tty = devpts_get_tty(idx);
+		if (tty && driver->subtype == PTY_TYPE_MASTER)
+			tty = tty->link;
+	} else {
+		tty = driver->ttys[idx];
+	}
+	if (tty) goto fast_track;
+
+	/*
+	 * 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 locked termios may be retained.)
+	 */
+
+	if (!try_module_get(driver->owner)) {
+		retval = -ENODEV;
+		goto end_init;
+	}
+
+	o_tty = NULL;
+	tp = o_tp = NULL;
+	ltp = o_ltp = NULL;
+
+	tty = alloc_tty_struct();
+	if(!tty)
+		goto fail_no_mem;
+	initialize_tty_struct(tty);
+	tty->driver = driver;
+	tty->index = idx;
+	tty_line_name(driver, idx, tty->name);
+
+	if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
+		tp_loc = &tty->termios;
+		ltp_loc = &tty->termios_locked;
+	} else {
+		tp_loc = &driver->termios[idx];
+		ltp_loc = &driver->termios_locked[idx];
+	}
+
+	if (!*tp_loc) {
+		tp = (struct termios *) kmalloc(sizeof(struct termios),
+						GFP_KERNEL);
+		if (!tp)
+			goto free_mem_out;
+		*tp = driver->init_termios;
+	}
+
+	if (!*ltp_loc) {
+		ltp = (struct termios *) kmalloc(sizeof(struct termios),
+						 GFP_KERNEL);
+		if (!ltp)
+			goto free_mem_out;
+		memset(ltp, 0, sizeof(struct termios));
+	}
+
+	if (driver->type == TTY_DRIVER_TYPE_PTY) {
+		o_tty = alloc_tty_struct();
+		if (!o_tty)
+			goto free_mem_out;
+		initialize_tty_struct(o_tty);
+		o_tty->driver = driver->other;
+		o_tty->index = idx;
+		tty_line_name(driver->other, idx, o_tty->name);
+
+		if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
+			o_tp_loc = &o_tty->termios;
+			o_ltp_loc = &o_tty->termios_locked;
+		} else {
+			o_tp_loc = &driver->other->termios[idx];
+			o_ltp_loc = &driver->other->termios_locked[idx];
+		}
+
+		if (!*o_tp_loc) {
+			o_tp = (struct termios *)
+				kmalloc(sizeof(struct termios), GFP_KERNEL);
+			if (!o_tp)
+				goto free_mem_out;
+			*o_tp = driver->other->init_termios;
+		}
+
+		if (!*o_ltp_loc) {
+			o_ltp = (struct termios *)
+				kmalloc(sizeof(struct termios), GFP_KERNEL);
+			if (!o_ltp)
+				goto free_mem_out;
+			memset(o_ltp, 0, sizeof(struct termios));
+		}
+
+		/*
+		 * Everything allocated ... set up the o_tty structure.
+		 */
+		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)
+			*o_ltp_loc = o_ltp;
+		o_tty->termios = *o_tp_loc;
+		o_tty->termios_locked = *o_ltp_loc;
+		driver->other->refcount++;
+		if (driver->subtype == PTY_TYPE_MASTER)
+			o_tty->count++;
+
+		/* Establish the links in both directions */
+		tty->link   = o_tty;
+		o_tty->link = tty;
+	}
+
+	/* 
+	 * All structures have been allocated, so now we install them.
+	 * Failures after this point use release_mem to clean up, so 
+	 * there's no need to null out the local pointers.
+	 */
+	if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+		driver->ttys[idx] = tty;
+	}
+	
+	if (!*tp_loc)
+		*tp_loc = tp;
+	if (!*ltp_loc)
+		*ltp_loc = ltp;
+	tty->termios = *tp_loc;
+	tty->termios_locked = *ltp_loc;
+	driver->refcount++;
+	tty->count++;
+
+	/* 
+	 * Structures all installed ... call the ldisc open routines.
+	 * If we fail here just call release_mem to clean up.  No need
+	 * to decrement the use counts, as release_mem doesn't care.
+	 */
+
+	if (tty->ldisc.open) {
+		retval = (tty->ldisc.open)(tty);
+		if (retval)
+			goto release_mem_out;
+	}
+	if (o_tty && o_tty->ldisc.open) {
+		retval = (o_tty->ldisc.open)(o_tty);
+		if (retval) {
+			if (tty->ldisc.close)
+				(tty->ldisc.close)(tty);
+			goto release_mem_out;
+		}
+		tty_ldisc_enable(o_tty);
+	}
+	tty_ldisc_enable(tty);
+	goto success;
+
+	/*
+	 * This fast open can be used if the tty is already open.
+	 * No memory is allocated, and the only failures are from
+	 * attempting to open a closing tty or attempting multiple
+	 * opens on a pty master.
+	 */
+fast_track:
+	if (test_bit(TTY_CLOSING, &tty->flags)) {
+		retval = -EIO;
+		goto end_init;
+	}
+	if (driver->type == TTY_DRIVER_TYPE_PTY &&
+	    driver->subtype == PTY_TYPE_MASTER) {
+		/*
+		 * special case for PTY masters: only one open permitted, 
+		 * and the slave side open count is incremented as well.
+		 */
+		if (tty->count) {
+			retval = -EIO;
+			goto end_init;
+		}
+		tty->link->count++;
+	}
+	tty->count++;
+	tty->driver = driver; /* N.B. why do this every time?? */
+
+	/* FIXME */
+	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 semaphore */
+end_init:
+	return retval;
+
+	/* Release locally allocated memory ... nothing placed in slots */
+free_mem_out:
+	if (o_tp)
+		kfree(o_tp);
+	if (o_tty)
+		free_tty_struct(o_tty);
+	if (ltp)
+		kfree(ltp);
+	if (tp)
+		kfree(tp);
+	free_tty_struct(tty);
+
+fail_no_mem:
+	module_put(driver->owner);
+	retval = -ENOMEM;
+	goto end_init;
+
+	/* call the tty release_mem routine to clean out this slot */
+release_mem_out:
+	printk(KERN_INFO "init_dev: ldisc open failed, "
+			 "clearing slot %d\n", idx);
+	release_mem(tty, idx);
+	goto end_init;
+}
+
+/*
+ * Releases memory associated with a tty structure, and clears out the
+ * driver table slots.
+ */
+static void release_mem(struct tty_struct *tty, int idx)
+{
+	struct tty_struct *o_tty;
+	struct termios *tp;
+	int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM;
+
+	if ((o_tty = tty->link) != NULL) {
+		if (!devpts)
+			o_tty->driver->ttys[idx] = NULL;
+		if (o_tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
+			tp = o_tty->termios;
+			if (!devpts)
+				o_tty->driver->termios[idx] = NULL;
+			kfree(tp);
+
+			tp = o_tty->termios_locked;
+			if (!devpts)
+				o_tty->driver->termios_locked[idx] = NULL;
+			kfree(tp);
+		}
+		o_tty->magic = 0;
+		o_tty->driver->refcount--;
+		file_list_lock();
+		list_del_init(&o_tty->tty_files);
+		file_list_unlock();
+		free_tty_struct(o_tty);
+	}
+
+	if (!devpts)
+		tty->driver->ttys[idx] = NULL;
+	if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
+		tp = tty->termios;
+		if (!devpts)
+			tty->driver->termios[idx] = NULL;
+		kfree(tp);
+
+		tp = tty->termios_locked;
+		if (!devpts)
+			tty->driver->termios_locked[idx] = NULL;
+		kfree(tp);
+	}
+
+	tty->magic = 0;
+	tty->driver->refcount--;
+	file_list_lock();
+	list_del_init(&tty->tty_files);
+	file_list_unlock();
+	module_put(tty->driver->owner);
+	free_tty_struct(tty);
+}
+
+/*
+ * Even releasing the tty structures is a tricky business.. We have
+ * to be very careful that the structures are all released at the
+ * same time, as interrupts might otherwise get the wrong pointers.
+ *
+ * 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)
+{
+	struct tty_struct *tty, *o_tty;
+	int	pty_master, tty_closing, o_tty_closing, do_sleep;
+	int	devpts_master, devpts;
+	int	idx;
+	char	buf[64];
+	unsigned long flags;
+	
+	tty = (struct tty_struct *)filp->private_data;
+	if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "release_dev"))
+		return;
+
+	check_tty_count(tty, "release_dev");
+
+	tty_fasync(-1, filp, 0);
+
+	idx = tty->index;
+	pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+		      tty->driver->subtype == PTY_TYPE_MASTER);
+	devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0;
+	devpts_master = pty_master && devpts;
+	o_tty = tty->link;
+
+#ifdef TTY_PARANOIA_CHECK
+	if (idx < 0 || idx >= tty->driver->num) {
+		printk(KERN_DEBUG "release_dev: bad idx when trying to "
+				  "free (%s)\n", tty->name);
+		return;
+	}
+	if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+		if (tty != tty->driver->ttys[idx]) {
+			printk(KERN_DEBUG "release_dev: driver.table[%d] not tty "
+			       "for (%s)\n", idx, tty->name);
+			return;
+		}
+		if (tty->termios != tty->driver->termios[idx]) {
+			printk(KERN_DEBUG "release_dev: driver.termios[%d] not termios "
+			       "for (%s)\n",
+			       idx, tty->name);
+			return;
+		}
+		if (tty->termios_locked != tty->driver->termios_locked[idx]) {
+			printk(KERN_DEBUG "release_dev: driver.termios_locked[%d] not "
+			       "termios_locked for (%s)\n",
+			       idx, tty->name);
+			return;
+		}
+	}
+#endif
+
+#ifdef TTY_DEBUG_HANGUP
+	printk(KERN_DEBUG "release_dev of %s (tty count=%d)...",
+	       tty_name(tty, buf), tty->count);
+#endif
+
+#ifdef TTY_PARANOIA_CHECK
+	if (tty->driver->other &&
+	     !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+		if (o_tty != tty->driver->other->ttys[idx]) {
+			printk(KERN_DEBUG "release_dev: other->table[%d] "
+					  "not o_tty for (%s)\n",
+			       idx, tty->name);
+			return;
+		}
+		if (o_tty->termios != tty->driver->other->termios[idx]) {
+			printk(KERN_DEBUG "release_dev: other->termios[%d] "
+					  "not o_termios for (%s)\n",
+			       idx, tty->name);
+			return;
+		}
+		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",
+			       idx, tty->name);
+			return;
+		}
+		if (o_tty->link != tty) {
+			printk(KERN_DEBUG "release_dev: bad pty pointers\n");
+			return;
+		}
+	}
+#endif
+	if (tty->driver->close)
+		tty->driver->close(tty, filp);
+
+	/*
+	 * 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
+	 * wait queues and kick everyone out _before_ actually starting to
+	 * close.  This ensures that we won't block while releasing the tty
+	 * structure.
+	 *
+	 * The test for the o_tty closing is necessary, since the master and
+	 * slave sides may close in any order.  If the slave side closes out
+	 * first, its count will be one, since the master side holds an open.
+	 * Thus this test wouldn't be triggered at the time the slave closes,
+	 * so we do it now.
+	 *
+	 * Note that it's possible for the tty to be opened again while we're
+	 * flushing out waiters.  By recalculating the closing flags before
+	 * each iteration we avoid any problems.
+	 */
+	while (1) {
+		/* Guard against races with tty->count changes elsewhere and
+		   opens on /dev/tty */
+		   
+		down(&tty_sem);
+		tty_closing = tty->count <= 1;
+		o_tty_closing = o_tty &&
+			(o_tty->count <= (pty_master ? 1 : 0));
+		up(&tty_sem);
+		do_sleep = 0;
+
+		if (tty_closing) {
+			if (waitqueue_active(&tty->read_wait)) {
+				wake_up(&tty->read_wait);
+				do_sleep++;
+			}
+			if (waitqueue_active(&tty->write_wait)) {
+				wake_up(&tty->write_wait);
+				do_sleep++;
+			}
+		}
+		if (o_tty_closing) {
+			if (waitqueue_active(&o_tty->read_wait)) {
+				wake_up(&o_tty->read_wait);
+				do_sleep++;
+			}
+			if (waitqueue_active(&o_tty->write_wait)) {
+				wake_up(&o_tty->write_wait);
+				do_sleep++;
+			}
+		}
+		if (!do_sleep)
+			break;
+
+		printk(KERN_WARNING "release_dev: %s: read/write wait queue "
+				    "active!\n", tty_name(tty, buf));
+		schedule();
+	}	
+
+	/*
+	 * 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.
+	 */
+	 
+	down(&tty_sem);
+	if (pty_master) {
+		if (--o_tty->count < 0) {
+			printk(KERN_WARNING "release_dev: bad pty slave count "
+					    "(%d) for %s\n",
+			       o_tty->count, tty_name(o_tty, buf));
+			o_tty->count = 0;
+		}
+	}
+	if (--tty->count < 0) {
+		printk(KERN_WARNING "release_dev: bad tty->count (%d) for %s\n",
+		       tty->count, tty_name(tty, buf));
+		tty->count = 0;
+	}
+	up(&tty_sem);
+	
+	/*
+	 * We've decremented tty->count, so we need to remove this file
+	 * descriptor off the tty->tty_files list; this serves two
+	 * purposes:
+	 *  - check_tty_count sees the correct number of file descriptors
+	 *    associated with this tty.
+	 *  - do_tty_hangup no longer sees this file descriptor as
+	 *    something that needs to be handled for hangups.
+	 */
+	file_kill(filp);
+	filp->private_data = NULL;
+
+	/*
+	 * Perform some housekeeping before deciding whether to return.
+	 *
+	 * Set the TTY_CLOSING flag if this was the last open.  In the
+	 * 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)
+		set_bit(TTY_CLOSING, &tty->flags);
+	if(o_tty_closing)
+		set_bit(TTY_CLOSING, &o_tty->flags);
+
+	/*
+	 * If _either_ side is closing, make sure there aren't any
+	 * processes that still think tty or o_tty is their controlling
+	 * tty.
+	 */
+	if (tty_closing || o_tty_closing) {
+		struct task_struct *p;
+
+		read_lock(&tasklist_lock);
+		do_each_task_pid(tty->session, PIDTYPE_SID, p) {
+			p->signal->tty = NULL;
+		} while_each_task_pid(tty->session, PIDTYPE_SID, p);
+		if (o_tty)
+			do_each_task_pid(o_tty->session, PIDTYPE_SID, p) {
+				p->signal->tty = NULL;
+			} while_each_task_pid(o_tty->session, PIDTYPE_SID, p);
+		read_unlock(&tasklist_lock);
+	}
+
+	/* 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
+	/*
+	 * Prevent flush_to_ldisc() from rescheduling the work for later.  Then
+	 * kill any delayed work. As this is the final close it does not
+	 * race with the set_ldisc code path.
+	 */
+	clear_bit(TTY_LDISC, &tty->flags);
+	clear_bit(TTY_DONT_FLIP, &tty->flags);
+	cancel_delayed_work(&tty->flip.work);
+
+	/*
+	 * Wait for ->hangup_work and ->flip.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)
+	{
+		spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+		wait_event(tty_ldisc_wait, tty->ldisc.refcount == 0);
+		spin_lock_irqsave(&tty_ldisc_lock, flags);
+	}
+	spin_unlock_irqrestore(&tty_ldisc_lock, flags);
+	/*
+	 * Shutdown the current line discipline, and reset it to N_TTY.
+	 * N.B. why reset ldisc when we're releasing the memory??
+	 *
+	 * FIXME: this MUST get fixed for the new reflocking
+	 */
+	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); 
+	if (o_tty) {
+		/* FIXME: could o_tty be in setldisc here ? */
+		clear_bit(TTY_LDISC, &o_tty->flags);
+		if (o_tty->ldisc.close)
+			(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); 
+	}
+	/*
+	 * The release_mem function takes care of the details of clearing
+	 * the slots and preserving the termios structure.
+	 */
+	release_mem(tty, idx);
+
+#ifdef CONFIG_UNIX98_PTYS
+	/* Make this pty number available for reallocation */
+	if (devpts) {
+		down(&allocated_ptys_lock);
+		idr_remove(&allocated_ptys, idx);
+		up(&allocated_ptys_lock);
+	}
+#endif
+
+}
+
+/*
+ * tty_open and tty_release keep up the tty count that contains the
+ * number of opens done on a tty. We cannot use the inode-count, as
+ * different inodes might point to the same tty.
+ *
+ * Open-counting is needed for pty masters, as well as for keeping
+ * track of serial lines: DTR is dropped when the last close happens.
+ * (This is not done solely through tty->count, now.  - Ted 1/27/92)
+ *
+ * The termios state of a pty is reset on first open so that
+ * settings don't persist across reuse.
+ */
+static int tty_open(struct inode * inode, struct file * filp)
+{
+	struct tty_struct *tty;
+	int noctty, retval;
+	struct tty_driver *driver;
+	int index;
+	dev_t device = inode->i_rdev;
+	unsigned short saved_flags = filp->f_flags;
+
+	nonseekable_open(inode, filp);
+	
+retry_open:
+	noctty = filp->f_flags & O_NOCTTY;
+	index  = -1;
+	retval = 0;
+	
+	down(&tty_sem);
+
+	if (device == MKDEV(TTYAUX_MAJOR,0)) {
+		if (!current->signal->tty) {
+			up(&tty_sem);
+			return -ENXIO;
+		}
+		driver = current->signal->tty->driver;
+		index = current->signal->tty->index;
+		filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */
+		/* noctty = 1; */
+		goto got_driver;
+	}
+#ifdef CONFIG_VT
+	if (device == MKDEV(TTY_MAJOR,0)) {
+		extern struct tty_driver *console_driver;
+		driver = console_driver;
+		index = fg_console;
+		noctty = 1;
+		goto got_driver;
+	}
+#endif
+	if (device == MKDEV(TTYAUX_MAJOR,1)) {
+		driver = console_device(&index);
+		if (driver) {
+			/* Don't let /dev/console block */
+			filp->f_flags |= O_NONBLOCK;
+			noctty = 1;
+			goto got_driver;
+		}
+		up(&tty_sem);
+		return -ENODEV;
+	}
+
+	driver = get_tty_driver(device, &index);
+	if (!driver) {
+		up(&tty_sem);
+		return -ENODEV;
+	}
+got_driver:
+	retval = init_dev(driver, index, &tty);
+	up(&tty_sem);
+	if (retval)
+		return retval;
+
+	filp->private_data = tty;
+	file_move(filp, &tty->tty_files);
+	check_tty_count(tty, "tty_open");
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_MASTER)
+		noctty = 1;
+#ifdef TTY_DEBUG_HANGUP
+	printk(KERN_DEBUG "opening %s...", tty->name);
+#endif
+	if (!retval) {
+		if (tty->driver->open)
+			retval = tty->driver->open(tty, filp);
+		else
+			retval = -ENODEV;
+	}
+	filp->f_flags = saved_flags;
+
+	if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN))
+		retval = -EBUSY;
+
+	if (retval) {
+#ifdef TTY_DEBUG_HANGUP
+		printk(KERN_DEBUG "error %d in opening %s...", retval,
+		       tty->name);
+#endif
+		release_dev(filp);
+		if (retval != -ERESTARTSYS)
+			return retval;
+		if (signal_pending(current))
+			return retval;
+		schedule();
+		/*
+		 * Need to reset f_op in case a hangup happened.
+		 */
+		if (filp->f_op == &hung_up_tty_fops)
+			filp->f_op = &tty_fops;
+		goto retry_open;
+	}
+	if (!noctty &&
+	    current->signal->leader &&
+	    !current->signal->tty &&
+	    tty->session == 0) {
+	    	task_lock(current);
+		current->signal->tty = tty;
+		task_unlock(current);
+		current->signal->tty_old_pgrp = 0;
+		tty->session = current->signal->session;
+		tty->pgrp = process_group(current);
+	}
+	return 0;
+}
+
+#ifdef CONFIG_UNIX98_PTYS
+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. */
+	down(&allocated_ptys_lock);
+	if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) {
+		up(&allocated_ptys_lock);
+		return -ENOMEM;
+	}
+	idr_ret = idr_get_new(&allocated_ptys, NULL, &index);
+	if (idr_ret < 0) {
+		up(&allocated_ptys_lock);
+		if (idr_ret == -EAGAIN)
+			return -ENOMEM;
+		return -EIO;
+	}
+	if (index >= pty_limit) {
+		idr_remove(&allocated_ptys, index);
+		up(&allocated_ptys_lock);
+		return -EIO;
+	}
+	up(&allocated_ptys_lock);
+
+	down(&tty_sem);
+	retval = init_dev(ptm_driver, index, &tty);
+	up(&tty_sem);
+	
+	if (retval)
+		goto out;
+
+	set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
+	filp->private_data = tty;
+	file_move(filp, &tty->tty_files);
+
+	retval = -ENOMEM;
+	if (devpts_pty_new(tty->link))
+		goto out1;
+
+	check_tty_count(tty, "tty_open");
+	retval = ptm_driver->open(tty, filp);
+	if (!retval)
+		return 0;
+out1:
+	release_dev(filp);
+out:
+	down(&allocated_ptys_lock);
+	idr_remove(&allocated_ptys, index);
+	up(&allocated_ptys_lock);
+	return retval;
+}
+#endif
+
+static int tty_release(struct inode * inode, struct file * filp)
+{
+	lock_kernel();
+	release_dev(filp);
+	unlock_kernel();
+	return 0;
+}
+
+/* No kernel lock held - fine */
+static unsigned int tty_poll(struct file * filp, poll_table * wait)
+{
+	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_dentry->d_inode, "tty_poll"))
+		return 0;
+		
+	ld = tty_ldisc_ref_wait(tty);
+	if (ld->poll)
+		ret = (ld->poll)(tty, filp, wait);
+	tty_ldisc_deref(ld);
+	return ret;
+}
+
+static int tty_fasync(int fd, struct file * filp, int on)
+{
+	struct tty_struct * tty;
+	int retval;
+
+	tty = (struct tty_struct *)filp->private_data;
+	if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_fasync"))
+		return 0;
+	
+	retval = fasync_helper(fd, filp, on, &tty->fasync);
+	if (retval <= 0)
+		return retval;
+
+	if (on) {
+		if (!waitqueue_active(&tty->read_wait))
+			tty->minimum_to_wake = 1;
+		retval = f_setown(filp, (-tty->pgrp) ? : current->pid, 0);
+		if (retval)
+			return retval;
+	} else {
+		if (!tty->fasync && !waitqueue_active(&tty->read_wait))
+			tty->minimum_to_wake = N_TTY_BUF_SIZE;
+	}
+	return 0;
+}
+
+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))
+		return -EFAULT;
+	ld = tty_ldisc_ref_wait(tty);
+	ld->receive_buf(tty, &ch, &mbz, 1);
+	tty_ldisc_deref(ld);
+	return 0;
+}
+
+static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg)
+{
+	if (copy_to_user(arg, &tty->winsize, sizeof(*arg)))
+		return -EFAULT;
+	return 0;
+}
+
+static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty,
+	struct winsize __user * arg)
+{
+	struct winsize tmp_ws;
+
+	if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
+		return -EFAULT;
+	if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg)))
+		return 0;
+#ifdef CONFIG_VT
+	if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) {
+		int rc;
+
+		acquire_console_sem();
+		rc = vc_resize(tty->driver_data, tmp_ws.ws_col, tmp_ws.ws_row);
+		release_console_sem();
+		if (rc)
+			return -ENXIO;
+	}
+#endif
+	if (tty->pgrp > 0)
+		kill_pg(tty->pgrp, SIGWINCH, 1);
+	if ((real_tty->pgrp != tty->pgrp) && (real_tty->pgrp > 0))
+		kill_pg(real_tty->pgrp, SIGWINCH, 1);
+	tty->winsize = tmp_ws;
+	real_tty->winsize = tmp_ws;
+	return 0;
+}
+
+static int tioccons(struct file *file)
+{
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	if (file->f_op->write == redirected_tty_write) {
+		struct file *f;
+		spin_lock(&redirect_lock);
+		f = redirect;
+		redirect = NULL;
+		spin_unlock(&redirect_lock);
+		if (f)
+			fput(f);
+		return 0;
+	}
+	spin_lock(&redirect_lock);
+	if (redirect) {
+		spin_unlock(&redirect_lock);
+		return -EBUSY;
+	}
+	get_file(file);
+	redirect = file;
+	spin_unlock(&redirect_lock);
+	return 0;
+}
+
+
+static int fionbio(struct file *file, int __user *p)
+{
+	int nonblock;
+
+	if (get_user(nonblock, p))
+		return -EFAULT;
+
+	if (nonblock)
+		file->f_flags |= O_NONBLOCK;
+	else
+		file->f_flags &= ~O_NONBLOCK;
+	return 0;
+}
+
+static int tiocsctty(struct tty_struct *tty, int arg)
+{
+	task_t *p;
+
+	if (current->signal->leader &&
+	    (current->signal->session == tty->session))
+		return 0;
+	/*
+	 * The process must be a session leader and
+	 * not have a controlling tty already.
+	 */
+	if (!current->signal->leader || current->signal->tty)
+		return -EPERM;
+	if (tty->session > 0) {
+		/*
+		 * This tty is already the controlling
+		 * tty for another session group!
+		 */
+		if ((arg == 1) && capable(CAP_SYS_ADMIN)) {
+			/*
+			 * Steal it away
+			 */
+
+			read_lock(&tasklist_lock);
+			do_each_task_pid(tty->session, PIDTYPE_SID, p) {
+				p->signal->tty = NULL;
+			} while_each_task_pid(tty->session, PIDTYPE_SID, p);
+			read_unlock(&tasklist_lock);
+		} else
+			return -EPERM;
+	}
+	task_lock(current);
+	current->signal->tty = tty;
+	task_unlock(current);
+	current->signal->tty_old_pgrp = 0;
+	tty->session = current->signal->session;
+	tty->pgrp = process_group(current);
+	return 0;
+}
+
+static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
+{
+	/*
+	 * (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(real_tty->pgrp, p);
+}
+
+static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
+{
+	pid_t pgrp;
+	int retval = tty_check_change(real_tty);
+
+	if (retval == -EIO)
+		return -ENOTTY;
+	if (retval)
+		return retval;
+	if (!current->signal->tty ||
+	    (current->signal->tty != real_tty) ||
+	    (real_tty->session != current->signal->session))
+		return -ENOTTY;
+	if (get_user(pgrp, p))
+		return -EFAULT;
+	if (pgrp < 0)
+		return -EINVAL;
+	if (session_of_pgrp(pgrp) != current->signal->session)
+		return -EPERM;
+	real_tty->pgrp = pgrp;
+	return 0;
+}
+
+static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
+{
+	/*
+	 * (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;
+	if (real_tty->session <= 0)
+		return -ENOTTY;
+	return put_user(real_tty->session, p);
+}
+
+static int tiocsetd(struct tty_struct *tty, int __user *p)
+{
+	int ldisc;
+
+	if (get_user(ldisc, p))
+		return -EFAULT;
+	return tty_set_ldisc(tty, ldisc);
+}
+
+static int send_break(struct tty_struct *tty, int duration)
+{
+	tty->driver->break_ctl(tty, -1);
+	if (!signal_pending(current)) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(duration);
+	}
+	tty->driver->break_ctl(tty, 0);
+	if (signal_pending(current))
+		return -EINTR;
+	return 0;
+}
+
+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 (retval >= 0)
+			retval = put_user(retval, p);
+	}
+	return retval;
+}
+
+static int
+tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd,
+	     unsigned __user *p)
+{
+	int retval = -EINVAL;
+
+	if (tty->driver->tiocmset) {
+		unsigned int set, clear, val;
+
+		retval = get_user(val, p);
+		if (retval)
+			return retval;
+
+		set = clear = 0;
+		switch (cmd) {
+		case TIOCMBIS:
+			set = val;
+			break;
+		case TIOCMBIC:
+			clear = val;
+			break;
+		case TIOCMSET:
+			set = val;
+			clear = ~val;
+			break;
+		}
+
+		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);
+	}
+	return retval;
+}
+
+/*
+ * 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)
+{
+	struct tty_struct *tty, *real_tty;
+	void __user *p = (void __user *)arg;
+	int retval;
+	struct tty_ldisc *ld;
+	
+	tty = (struct tty_struct *)file->private_data;
+	if (tty_paranoia_check(tty, inode, "tty_ioctl"))
+		return -EINVAL;
+
+	real_tty = tty;
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+	    tty->driver->subtype == PTY_TYPE_MASTER)
+		real_tty = tty->link;
+
+	/*
+	 * Break handling by driver
+	 */
+	if (!tty->driver->break_ctl) {
+		switch(cmd) {
+		case TIOCSBRK:
+		case TIOCCBRK:
+			if (tty->driver->ioctl)
+				return tty->driver->ioctl(tty, file, cmd, arg);
+			return -EINVAL;
+			
+		/* These two ioctl's always return success; even if */
+		/* the driver doesn't support them. */
+		case TCSBRK:
+		case TCSBRKP:
+			if (!tty->driver->ioctl)
+				return 0;
+			retval = tty->driver->ioctl(tty, file, cmd, arg);
+			if (retval == -ENOIOCTLCMD)
+				retval = 0;
+			return retval;
+		}
+	}
+
+	/*
+	 * Factor out some common prep work
+	 */
+	switch (cmd) {
+	case TIOCSETD:
+	case TIOCSBRK:
+	case TIOCCBRK:
+	case TCSBRK:
+	case TCSBRKP:			
+		retval = tty_check_change(tty);
+		if (retval)
+			return retval;
+		if (cmd != TIOCCBRK) {
+			tty_wait_until_sent(tty, 0);
+			if (signal_pending(current))
+				return -EINTR;
+		}
+		break;
+	}
+
+	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;
+			if (current->signal->leader)
+				disassociate_ctty(0);
+			task_lock(current);
+			current->signal->tty = NULL;
+			task_unlock(current);
+			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);
+#ifdef CONFIG_VT
+		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 */
+			/*
+			 * XXX is the above comment correct, or the
+			 * code below correct?  Is this ioctl used at
+			 * all by anyone?
+			 */
+			if (!arg)
+				return send_break(tty, HZ/4);
+			return 0;
+		case TCSBRKP:	/* support for POSIX tcsendbreak() */	
+			return send_break(tty, arg ? arg*(HZ/10) : HZ/4);
+
+		case TIOCMGET:
+			return tty_tiocmget(tty, file, p);
+
+		case TIOCMSET:
+		case TIOCMBIC:
+		case TIOCMBIS:
+			return tty_tiocmset(tty, file, cmd, p);
+	}
+	if (tty->driver->ioctl) {
+		retval = (tty->driver->ioctl)(tty, file, cmd, arg);
+		if (retval != -ENOIOCTLCMD)
+			return retval;
+	}
+	ld = tty_ldisc_ref_wait(tty);
+	retval = -EINVAL;
+	if (ld->ioctl) {
+		retval = ld->ioctl(tty, file, cmd, arg);
+		if (retval == -ENOIOCTLCMD)
+			retval = -EINVAL;
+	}
+	tty_ldisc_deref(ld);
+	return retval;
+}
+
+
+/*
+ * This implements the "Secure Attention Key" ---  the idea is to
+ * 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
+ * with the current tty must be dead before the new getty is allowed
+ * to spawn.
+ *
+ * Now, if it would be correct ;-/ The current code has a nasty hole -
+ * it doesn't catch files in flight. We may send the descriptor to ourselves
+ * via AF_UNIX socket, close it and later fetch from socket. FIXME.
+ *
+ * Nasty bug: do_SAK is being called in interrupt context.  This can
+ * deadlock.  We punt it up to process context.  AKPM - 16Mar2001
+ */
+static void __do_SAK(void *arg)
+{
+#ifdef TTY_SOFT_SAK
+	tty_hangup(tty);
+#else
+	struct tty_struct *tty = arg;
+	struct task_struct *p;
+	int session;
+	int		i;
+	struct file	*filp;
+	struct tty_ldisc *disc;
+	
+	if (!tty)
+		return;
+	session  = tty->session;
+	
+	/* We don't want an ldisc switch during this */
+	disc = tty_ldisc_ref(tty);
+	if (disc && disc->flush_buffer)
+		disc->flush_buffer(tty);
+	tty_ldisc_deref(disc);
+
+	if (tty->driver->flush_buffer)
+		tty->driver->flush_buffer(tty);
+	
+	read_lock(&tasklist_lock);
+	do_each_task_pid(session, PIDTYPE_SID, p) {
+		if (p->signal->tty == tty || session > 0) {
+			printk(KERN_NOTICE "SAK: killed process %d"
+			    " (%s): p->signal->session==tty->session\n",
+			    p->pid, p->comm);
+			send_sig(SIGKILL, p, 1);
+			continue;
+		}
+		task_lock(p);
+		if (p->files) {
+			spin_lock(&p->files->file_lock);
+			for (i=0; i < p->files->max_fds; i++) {
+				filp = fcheck_files(p->files, i);
+				if (!filp)
+					continue;
+				if (filp->f_op->read == tty_read &&
+				    filp->private_data == tty) {
+					printk(KERN_NOTICE "SAK: killed process %d"
+					    " (%s): fd#%d opened to the tty\n",
+					    p->pid, p->comm, i);
+					send_sig(SIGKILL, p, 1);
+					break;
+				}
+			}
+			spin_unlock(&p->files->file_lock);
+		}
+		task_unlock(p);
+	} while_each_task_pid(session, PIDTYPE_SID, p);
+	read_unlock(&tasklist_lock);
+#endif
+}
+
+/*
+ * The tq handling here is a little racy - tty->SAK_work may already be queued.
+ * Fortunately we don't need to worry, because if ->SAK_work is already queued,
+ * the values which we write to it will be identical to the values which it
+ * already has. --akpm
+ */
+void do_SAK(struct tty_struct *tty)
+{
+	if (!tty)
+		return;
+	PREPARE_WORK(&tty->SAK_work, __do_SAK, tty);
+	schedule_work(&tty->SAK_work);
+}
+
+EXPORT_SYMBOL(do_SAK);
+
+/*
+ * This routine is called out of the software interrupt to flush data
+ * from the flip buffer to the line discipline. 
+ */
+ 
+static void flush_to_ldisc(void *private_)
+{
+	struct tty_struct *tty = (struct tty_struct *) private_;
+	unsigned char	*cp;
+	char		*fp;
+	int		count;
+	unsigned long 	flags;
+	struct tty_ldisc *disc;
+
+	disc = tty_ldisc_ref(tty);
+	if (disc == NULL)	/*  !TTY_LDISC */
+		return;
+
+	if (test_bit(TTY_DONT_FLIP, &tty->flags)) {
+		/*
+		 * Do it after the next timer tick:
+		 */
+		schedule_delayed_work(&tty->flip.work, 1);
+		goto out;
+	}
+	spin_lock_irqsave(&tty->read_lock, flags);
+	if (tty->flip.buf_num) {
+		cp = tty->flip.char_buf + TTY_FLIPBUF_SIZE;
+		fp = tty->flip.flag_buf + TTY_FLIPBUF_SIZE;
+		tty->flip.buf_num = 0;
+		tty->flip.char_buf_ptr = tty->flip.char_buf;
+		tty->flip.flag_buf_ptr = tty->flip.flag_buf;
+	} else {
+		cp = tty->flip.char_buf;
+		fp = tty->flip.flag_buf;
+		tty->flip.buf_num = 1;
+		tty->flip.char_buf_ptr = tty->flip.char_buf + TTY_FLIPBUF_SIZE;
+		tty->flip.flag_buf_ptr = tty->flip.flag_buf + TTY_FLIPBUF_SIZE;
+	}
+	count = tty->flip.count;
+	tty->flip.count = 0;
+	spin_unlock_irqrestore(&tty->read_lock, flags);
+
+	disc->receive_buf(tty, cp, fp, count);
+out:
+	tty_ldisc_deref(disc);
+}
+
+/*
+ * Routine which returns the baud rate of the tty
+ *
+ * Note that the baud_table needs to be kept in sync with the
+ * include/asm/termbits.h file.
+ */
+static int baud_table[] = {
+	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
+	9600, 19200, 38400, 57600, 115200, 230400, 460800,
+#ifdef __sparc__
+	76800, 153600, 307200, 614400, 921600
+#else
+	500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
+	2500000, 3000000, 3500000, 4000000
+#endif
+};
+
+static int n_baud_table = ARRAY_SIZE(baud_table);
+
+/**
+ *	tty_termios_baud_rate
+ *	@termios: termios structure
+ *
+ *	Convert termios baud rate data into a speed. This should be called
+ *	with the termios lock held if this termios is a terminal termios
+ *	structure. May change the termios data.
+ */
+ 
+int tty_termios_baud_rate(struct termios *termios)
+{
+	unsigned int cbaud;
+	
+	cbaud = termios->c_cflag & CBAUD;
+
+	if (cbaud & CBAUDEX) {
+		cbaud &= ~CBAUDEX;
+
+		if (cbaud < 1 || cbaud + 15 > n_baud_table)
+			termios->c_cflag &= ~CBAUDEX;
+		else
+			cbaud += 15;
+	}
+	return baud_table[cbaud];
+}
+
+EXPORT_SYMBOL(tty_termios_baud_rate);
+
+/**
+ *	tty_get_baud_rate	-	get tty bit rates
+ *	@tty: tty to query
+ *
+ *	Returns the baud rate as an integer for this terminal. The
+ *	termios lock must be held by the caller and the terminal bit
+ *	flags may be updated.
+ */
+ 
+int tty_get_baud_rate(struct tty_struct *tty)
+{
+	int baud = tty_termios_baud_rate(tty->termios);
+
+	if (baud == 38400 && tty->alt_speed) {
+		if (!tty->warned) {
+			printk(KERN_WARNING "Use of setserial/setrocket to "
+					    "set SPD_* flags is deprecated\n");
+			tty->warned = 1;
+		}
+		baud = tty->alt_speed;
+	}
+	
+	return baud;
+}
+
+EXPORT_SYMBOL(tty_get_baud_rate);
+
+/**
+ *	tty_flip_buffer_push	-	terminal
+ *	@tty: tty to push
+ *
+ *	Queue a push of the terminal flip buffers to the line discipline. This
+ *	function must not be called from IRQ context if tty->low_latency is set.
+ *
+ *	In the event of the queue being busy for flipping the work will be
+ *	held off and retried later.
+ */
+
+void tty_flip_buffer_push(struct tty_struct *tty)
+{
+	if (tty->low_latency)
+		flush_to_ldisc((void *) tty);
+	else
+		schedule_delayed_work(&tty->flip.work, 1);
+}
+
+EXPORT_SYMBOL(tty_flip_buffer_push);
+
+/*
+ * This subroutine initializes a tty structure.
+ */
+static void initialize_tty_struct(struct tty_struct *tty)
+{
+	memset(tty, 0, sizeof(struct tty_struct));
+	tty->magic = TTY_MAGIC;
+	tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
+	tty->pgrp = -1;
+	tty->overrun_time = jiffies;
+	tty->flip.char_buf_ptr = tty->flip.char_buf;
+	tty->flip.flag_buf_ptr = tty->flip.flag_buf;
+	INIT_WORK(&tty->flip.work, flush_to_ldisc, tty);
+	init_MUTEX(&tty->flip.pty_sem);
+	init_MUTEX(&tty->termios_sem);
+	init_waitqueue_head(&tty->write_wait);
+	init_waitqueue_head(&tty->read_wait);
+	INIT_WORK(&tty->hangup_work, do_tty_hangup, tty);
+	sema_init(&tty->atomic_read, 1);
+	sema_init(&tty->atomic_write, 1);
+	spin_lock_init(&tty->read_lock);
+	INIT_LIST_HEAD(&tty->tty_files);
+	INIT_WORK(&tty->SAK_work, NULL, NULL);
+}
+
+/*
+ * The default put_char routine if the driver did not define one.
+ */
+static void tty_default_put_char(struct tty_struct *tty, unsigned char ch)
+{
+	tty->driver->write(tty, &ch, 1);
+}
+
+static struct class_simple *tty_class;
+
+/**
+ * tty_register_device - 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.
+ *
+ * This call is required to be made to register an individual tty device if
+ * the tty driver's flags have the TTY_DRIVER_NO_DEVFS bit set.  If that
+ * bit is not set, this function should not be called.
+ */
+void tty_register_device(struct tty_driver *driver, unsigned index,
+			 struct device *device)
+{
+	char name[64];
+	dev_t dev = MKDEV(driver->major, driver->minor_start) + index;
+
+	if (index >= driver->num) {
+		printk(KERN_ERR "Attempt to register invalid tty line number "
+		       " (%d).\n", index);
+		return;
+	}
+
+	devfs_mk_cdev(dev, S_IFCHR | S_IRUSR | S_IWUSR,
+			"%s%d", driver->devfs_name, index + driver->name_base);
+
+	if (driver->type == TTY_DRIVER_TYPE_PTY)
+		pty_line_name(driver, index, name);
+	else
+		tty_line_name(driver, index, name);
+	class_simple_device_add(tty_class, dev, device, name);
+}
+
+/**
+ * tty_unregister_device - unregister a tty device
+ * @driver: the tty driver that describes the tty device
+ * @index: the index in the tty driver for this tty device
+ *
+ * If a tty device is registered with a call to tty_register_device() then
+ * this function must be made when the tty device is gone.
+ */
+void tty_unregister_device(struct tty_driver *driver, unsigned index)
+{
+	devfs_remove("%s%d", driver->devfs_name, index + driver->name_base);
+	class_simple_device_remove(MKDEV(driver->major, driver->minor_start) + index);
+}
+
+EXPORT_SYMBOL(tty_register_device);
+EXPORT_SYMBOL(tty_unregister_device);
+
+struct tty_driver *alloc_tty_driver(int lines)
+{
+	struct tty_driver *driver;
+
+	driver = kmalloc(sizeof(struct tty_driver), GFP_KERNEL);
+	if (driver) {
+		memset(driver, 0, sizeof(struct tty_driver));
+		driver->magic = TTY_DRIVER_MAGIC;
+		driver->num = lines;
+		/* later we'll move allocation of tables here */
+	}
+	return driver;
+}
+
+void put_tty_driver(struct tty_driver *driver)
+{
+	kfree(driver);
+}
+
+void tty_set_operations(struct tty_driver *driver, 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->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;
+}
+
+
+EXPORT_SYMBOL(alloc_tty_driver);
+EXPORT_SYMBOL(put_tty_driver);
+EXPORT_SYMBOL(tty_set_operations);
+
+/*
+ * Called by a tty driver to register itself.
+ */
+int tty_register_driver(struct tty_driver *driver)
+{
+	int error;
+        int i;
+	dev_t dev;
+	void **p = NULL;
+
+	if (driver->flags & TTY_DRIVER_INSTALLED)
+		return 0;
+
+	if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+		p = kmalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL);
+		if (!p)
+			return -ENOMEM;
+		memset(p, 0, driver->num * 3 * sizeof(void *));
+	}
+
+	if (!driver->major) {
+		error = alloc_chrdev_region(&dev, driver->minor_start, driver->num,
+						(char*)driver->name);
+		if (!error) {
+			driver->major = MAJOR(dev);
+			driver->minor_start = MINOR(dev);
+		}
+	} else {
+		dev = MKDEV(driver->major, driver->minor_start);
+		error = register_chrdev_region(dev, driver->num,
+						(char*)driver->name);
+	}
+	if (error < 0) {
+		kfree(p);
+		return error;
+	}
+
+	if (p) {
+		driver->ttys = (struct tty_struct **)p;
+		driver->termios = (struct termios **)(p + driver->num);
+		driver->termios_locked = (struct termios **)(p + driver->num * 2);
+	} else {
+		driver->ttys = NULL;
+		driver->termios = NULL;
+		driver->termios_locked = NULL;
+	}
+
+	cdev_init(&driver->cdev, &tty_fops);
+	driver->cdev.owner = driver->owner;
+	error = cdev_add(&driver->cdev, dev, driver->num);
+	if (error) {
+		cdev_del(&driver->cdev);
+		unregister_chrdev_region(dev, driver->num);
+		driver->ttys = NULL;
+		driver->termios = driver->termios_locked = NULL;
+		kfree(p);
+		return error;
+	}
+
+	if (!driver->put_char)
+		driver->put_char = tty_default_put_char;
+	
+	list_add(&driver->tty_drivers, &tty_drivers);
+	
+	if ( !(driver->flags & TTY_DRIVER_NO_DEVFS) ) {
+		for(i = 0; i < driver->num; i++)
+		    tty_register_device(driver, i, NULL);
+	}
+	proc_tty_register_driver(driver);
+	return 0;
+}
+
+EXPORT_SYMBOL(tty_register_driver);
+
+/*
+ * Called by a tty driver to unregister itself.
+ */
+int tty_unregister_driver(struct tty_driver *driver)
+{
+	int i;
+	struct termios *tp;
+	void *p;
+
+	if (driver->refcount)
+		return -EBUSY;
+
+	unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
+				driver->num);
+
+	list_del(&driver->tty_drivers);
+
+	/*
+	 * Free the termios and termios_locked structures because
+	 * we don't want to get memory leaks when modular tty
+	 * drivers are removed from the kernel.
+	 */
+	for (i = 0; i < driver->num; i++) {
+		tp = driver->termios[i];
+		if (tp) {
+			driver->termios[i] = NULL;
+			kfree(tp);
+		}
+		tp = driver->termios_locked[i];
+		if (tp) {
+			driver->termios_locked[i] = NULL;
+			kfree(tp);
+		}
+		if (!(driver->flags & TTY_DRIVER_NO_DEVFS))
+			tty_unregister_device(driver, i);
+	}
+	p = driver->ttys;
+	proc_tty_unregister_driver(driver);
+	driver->ttys = NULL;
+	driver->termios = driver->termios_locked = NULL;
+	kfree(p);
+	cdev_del(&driver->cdev);
+	return 0;
+}
+
+EXPORT_SYMBOL(tty_unregister_driver);
+
+
+/*
+ * Initialize the console device. This is called *early*, so
+ * we can't necessarily depend on lots of kernel help here.
+ * Just do some early initializations, and do the complex setup
+ * later.
+ */
+void __init console_init(void)
+{
+	initcall_t *call;
+
+	/* Setup the default TTY line discipline. */
+	(void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
+
+	/*
+	 * set up the console device so that later boot sequences can 
+	 * inform about problems etc..
+	 */
+#ifdef CONFIG_EARLY_PRINTK
+	disable_early_printk();
+#endif
+#ifdef CONFIG_SERIAL_68360
+ 	/* This is not a console initcall. I know not what it's doing here.
+	   So I haven't moved it. dwmw2 */
+        rs_360_init();
+#endif
+	call = __con_initcall_start;
+	while (call < __con_initcall_end) {
+		(*call)();
+		call++;
+	}
+}
+
+#ifdef CONFIG_VT
+extern int vty_init(void);
+#endif
+
+static int __init tty_class_init(void)
+{
+	tty_class = class_simple_create(THIS_MODULE, "tty");
+	if (IS_ERR(tty_class))
+		return PTR_ERR(tty_class);
+	return 0;
+}
+
+postcore_initcall(tty_class_init);
+
+/* 3/2004 jmc: why do these devices exist? */
+
+static struct cdev tty_cdev, console_cdev;
+#ifdef CONFIG_UNIX98_PTYS
+static struct cdev ptmx_cdev;
+#endif
+#ifdef CONFIG_VT
+static struct cdev vc0_cdev;
+#endif
+
+/*
+ * Ok, now we can initialize the rest of the tty devices and can count
+ * on memory allocations, interrupts etc..
+ */
+static int __init tty_init(void)
+{
+	cdev_init(&tty_cdev, &tty_fops);
+	if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
+	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
+		panic("Couldn't register /dev/tty driver\n");
+	devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 0), S_IFCHR|S_IRUGO|S_IWUGO, "tty");
+	class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty");
+
+	cdev_init(&console_cdev, &console_fops);
+	if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
+	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
+		panic("Couldn't register /dev/console driver\n");
+	devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 1), S_IFCHR|S_IRUSR|S_IWUSR, "console");
+	class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 1), NULL, "console");
+
+#ifdef CONFIG_UNIX98_PTYS
+	cdev_init(&ptmx_cdev, &ptmx_fops);
+	if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
+	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
+		panic("Couldn't register /dev/ptmx driver\n");
+	devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 2), S_IFCHR|S_IRUGO|S_IWUGO, "ptmx");
+	class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
+#endif
+
+#ifdef CONFIG_VT
+	cdev_init(&vc0_cdev, &console_fops);
+	if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) ||
+	    register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0)
+		panic("Couldn't register /dev/tty0 driver\n");
+	devfs_mk_cdev(MKDEV(TTY_MAJOR, 0), S_IFCHR|S_IRUSR|S_IWUSR, "vc/0");
+	class_simple_device_add(tty_class, MKDEV(TTY_MAJOR, 0), NULL, "tty0");
+
+	vty_init();
+#endif
+	return 0;
+}
+module_init(tty_init);