pkt_sched: Move gso_skb into Qdisc.
[safe/jmp/linux-2.6] / drivers / char / tty_io.c
index 9820f86..7501310 100644 (file)
@@ -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>
@@ -77,6 +78,7 @@
 #include <linux/tty_flip.h>
 #include <linux/devpts_fs.h>
 #include <linux/file.h>
+#include <linux/fdtable.h>
 #include <linux/console.h>
 #include <linux/timer.h>
 #include <linux/ctype.h>
@@ -90,7 +92,6 @@
 #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>
 #include <linux/selection.h>
 
 #include <linux/kmod.h>
+#include <linux/nsproxy.h>
 
 #undef TTY_DEBUG_HANGUP
 
@@ -125,7 +127,7 @@ 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
@@ -135,9 +137,6 @@ 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 DECLARE_MUTEX(allocated_ptys_lock);
 static int ptmx_open(struct inode *, struct file *);
 #endif
 
@@ -145,19 +144,19 @@ 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);
@@ -243,7 +242,7 @@ 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++;
@@ -280,11 +279,11 @@ 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);
        }
@@ -330,7 +329,7 @@ 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;
@@ -360,7 +359,7 @@ 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;
@@ -383,7 +382,7 @@ 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);
        }
@@ -435,9 +434,9 @@ 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;
@@ -449,7 +448,7 @@ 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 ? */
@@ -519,7 +518,7 @@ 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);
@@ -555,7 +554,7 @@ 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);
@@ -607,7 +606,8 @@ 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)) {
@@ -637,7 +637,8 @@ 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)) {
@@ -659,12 +660,12 @@ 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);
@@ -677,10 +678,11 @@ 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
@@ -699,17 +701,17 @@ 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);
@@ -765,20 +767,18 @@ 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;
@@ -801,9 +801,9 @@ 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);
@@ -811,7 +811,7 @@ void tty_ldisc_put(int disc)
        module_put(ld->owner);
        spin_unlock_irqrestore(&tty_ldisc_lock, flags);
 }
-       
+
 EXPORT_SYMBOL_GPL(tty_ldisc_put);
 
 /**
@@ -850,11 +850,10 @@ 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;
        }
@@ -866,8 +865,8 @@ 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
@@ -877,12 +876,12 @@ 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;
 }
@@ -893,16 +892,16 @@ 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;
 }
@@ -918,19 +917,19 @@ 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);
 }
@@ -942,7 +941,7 @@ EXPORT_SYMBOL_GPL(tty_ldisc_deref);
  *     @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.
+ *     again. Do necessary wakeups for existing sleepers.
  *
  *     Note: nobody should set this bit except via this function. Clearing
  *     directly is allowed.
@@ -953,7 +952,7 @@ 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
@@ -965,7 +964,7 @@ 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;
@@ -1021,7 +1020,7 @@ 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);
@@ -1030,14 +1029,14 @@ 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)
@@ -1045,9 +1044,10 @@ 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);
@@ -1071,7 +1071,6 @@ restart:
        /*
         * Wait for ->hangup_work and ->buf.work handlers to terminate
         */
-        
        flush_scheduled_work();
        /* Shutdown the current discipline. */
        if (tty->ldisc.close)
@@ -1105,21 +1104,21 @@ 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)
@@ -1152,6 +1151,47 @@ 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
@@ -1160,55 +1200,69 @@ 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_unlock;
        }
        if (task_pgrp(current) == tty->pgrp)
-               return 0;
+               goto out_unlock;
+       spin_unlock_irqrestore(&tty->ctrl_lock, flags);
        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:
+       return ret;
+out_unlock:
+       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;
@@ -1219,7 +1273,7 @@ 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,
@@ -1232,7 +1286,7 @@ 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,
@@ -1245,7 +1299,7 @@ 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,
@@ -1257,7 +1311,7 @@ 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,
 };
@@ -1273,15 +1327,15 @@ 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);
                }
@@ -1298,12 +1352,12 @@ 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);
        }
@@ -1327,7 +1381,7 @@ 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
@@ -1354,11 +1408,12 @@ 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;
@@ -1372,7 +1427,7 @@ 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 ? */
@@ -1386,43 +1441,41 @@ 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) {
@@ -1436,37 +1489,42 @@ 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);
@@ -1485,11 +1543,10 @@ 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);
@@ -1503,10 +1560,10 @@ EXPORT_SYMBOL(tty_hangup);
  *
  *     The user has asked via system call for the terminal to be hung up.
  *     We do this synchronously so that when the syscall returns the process
- *     is complete. That guarantee is neccessary for security reasons.
+ *     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];
@@ -1515,6 +1572,7 @@ void tty_vhangup(struct tty_struct * tty)
 #endif
        do_tty_hangup(&tty->hangup_work);
 }
+
 EXPORT_SYMBOL(tty_vhangup);
 
 /**
@@ -1525,7 +1583,7 @@ 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);
 }
@@ -1533,8 +1591,12 @@ 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
@@ -1578,16 +1640,17 @@ 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);
@@ -1600,7 +1663,6 @@ void disassociate_ctty(int on_exit)
                        put_pid(old_pgrp);
                }
                mutex_unlock(&tty_mutex);
-               unlock_kernel();        
                return;
        }
        if (tty_pgrp) {
@@ -1619,10 +1681,13 @@ 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]"
@@ -1635,7 +1700,6 @@ void disassociate_ctty(int on_exit)
        read_lock(&tasklist_lock);
        session_clear_tty(task_session(current));
        read_unlock(&tasklist_lock);
-       unlock_kernel();
 }
 
 /**
@@ -1645,8 +1709,10 @@ 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);
 }
 
@@ -1666,21 +1732,26 @@ 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);
@@ -1690,27 +1761,31 @@ EXPORT_SYMBOL(stop_tty);
  *     @tty: tty to start
  *
  *     Start a tty that has been stopped if at all possible. Perform
- *     any neccessary wakeups and propagate the TIOCPKT status. If this
+ *     any necessary wakeups and propagate the TIOCPKT status. If this
  *     is the tty was previous stopped and is being started then the
  *     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);
 }
@@ -1728,17 +1803,15 @@ 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;
 
@@ -1752,13 +1825,11 @@ 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;
@@ -1794,7 +1865,7 @@ 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;
@@ -1846,9 +1917,7 @@ 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;
@@ -1890,21 +1959,25 @@ 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
@@ -1913,8 +1986,8 @@ 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;
 
@@ -1931,7 +2004,6 @@ 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);
 }
 
@@ -1953,8 +2025,8 @@ 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);
 }
 
 /**
@@ -2033,7 +2105,7 @@ 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.)
         */
 
@@ -2047,10 +2119,11 @@ 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);
 
@@ -2081,6 +2154,7 @@ 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);
 
@@ -2108,9 +2182,8 @@ 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)
@@ -2126,15 +2199,14 @@ 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)
@@ -2147,7 +2219,7 @@ 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.
@@ -2184,7 +2256,7 @@ 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) {
@@ -2197,11 +2269,11 @@ 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;
@@ -2303,7 +2375,7 @@ 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;
@@ -2311,9 +2383,10 @@ 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");
@@ -2373,7 +2446,7 @@ 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",
@@ -2386,8 +2459,8 @@ 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
@@ -2409,7 +2482,7 @@ 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 &&
@@ -2443,11 +2516,11 @@ 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) {
@@ -2463,7 +2536,7 @@ 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
@@ -2483,9 +2556,9 @@ 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);
 
        /*
@@ -2506,7 +2579,7 @@ 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
@@ -2521,17 +2594,16 @@ 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);
@@ -2546,12 +2618,12 @@ 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);
@@ -2559,7 +2631,7 @@ 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
@@ -2567,15 +2639,9 @@ static void release_dev(struct file * filp)
         */
        release_tty(tty, idx);
 
-#ifdef CONFIG_UNIX98_PTYS
        /* Make this pty number available for reallocation */
-       if (devpts) {
-               down(&allocated_ptys_lock);
-               idr_remove(&allocated_ptys, idx);
-               up(&allocated_ptys_lock);
-       }
-#endif
-
+       if (devpts)
+               devpts_kill_index(idx);
 }
 
 /**
@@ -2599,7 +2665,7 @@ 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;
@@ -2609,15 +2675,15 @@ 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);
@@ -2630,7 +2696,7 @@ 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;
@@ -2638,7 +2704,7 @@ 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 */
@@ -2671,14 +2737,15 @@ 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) {
@@ -2709,7 +2776,6 @@ got_driver:
                __proc_set_tty(current, tty);
        spin_unlock_irq(&current->sighand->siglock);
        mutex_unlock(&tty_mutex);
-       tty_audit_opening();
        return 0;
 }
 
@@ -2722,43 +2788,27 @@ 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. */
-       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);
+       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;
 
@@ -2766,23 +2816,19 @@ 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:
-       down(&allocated_ptys_lock);
-       idr_remove(&allocated_ptys, index);
-       up(&allocated_ptys_lock);
+       devpts_kill_index(index);
        return retval;
 }
 #endif
@@ -2799,7 +2845,7 @@ 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);
@@ -2819,16 +2865,16 @@ 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);
@@ -2836,15 +2882,16 @@ 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;
@@ -2854,6 +2901,7 @@ 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;
@@ -2861,6 +2909,7 @@ 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;
@@ -2876,7 +2925,7 @@ static int tty_fasync(int fd, struct file * filp, int on)
  *     @tty: tty to fake input into
  *     @p: pointer to character
  *
- *     Fake input to a tty device. Does the neccessary locking and
+ *     Fake input to a tty device. Does the necessary locking and
  *     input management.
  *
  *     FIXME: does not honour flow control ??
@@ -2892,7 +2941,7 @@ 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))
@@ -2914,7 +2963,7 @@ 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;
 
@@ -2943,9 +2992,11 @@ 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;
@@ -2959,14 +3010,25 @@ 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:
@@ -3027,10 +3089,13 @@ 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;
 }
 
@@ -3069,7 +3134,7 @@ 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 +3153,27 @@ unlock:
 }
 
 /**
+ *     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
  *     @real_tty: tty side of the tty pased by the user if a pty else the tty
@@ -3101,13 +3187,18 @@ 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_nr(real_tty->pgrp), p);
+       pid = tty_get_pgrp(real_tty);
+       ret =  put_user(pid_vnr(pid), p);
+       put_pid(pid);
+       return ret;
 }
 
 /**
@@ -3119,7 +3210,7 @@ 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)
@@ -3127,6 +3218,7 @@ 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;
@@ -3141,7 +3233,7 @@ static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t
        if (pgrp_nr < 0)
                return -EINVAL;
        rcu_read_lock();
-       pgrp = find_pid(pgrp_nr);
+       pgrp = find_vpid(pgrp_nr);
        retval = -ESRCH;
        if (!pgrp)
                goto out_unlock;
@@ -3149,8 +3241,10 @@ 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;
@@ -3178,7 +3272,7 @@ static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t _
                return -ENOTTY;
        if (!real_tty->session)
                return -ENOTTY;
-       return put_user(pid_nr(real_tty->session), p);
+       return put_user(pid_vnr(real_tty->session), p);
 }
 
 /**
@@ -3194,10 +3288,16 @@ 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;
 }
 
 /**
@@ -3217,10 +3317,10 @@ 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))
                return -EINTR;
@@ -3228,7 +3328,7 @@ static int send_break(struct tty_struct *tty, unsigned int duration)
 }
 
 /**
- *     tiocmget                -       get modem status
+ *     tty_tiocmget            -       get modem status
  *     @tty: tty device
  *     @file: user file pointer
  *     @p: pointer to result
@@ -3243,8 +3343,8 @@ 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);
@@ -3253,7 +3353,7 @@ 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
@@ -3270,7 +3370,7 @@ 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);
@@ -3294,7 +3394,7 @@ 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;
 }
@@ -3302,20 +3402,18 @@ 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)
@@ -3324,21 +3422,28 @@ 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;
@@ -3353,7 +3458,7 @@ 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;
@@ -3366,84 +3471,84 @@ 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;
        }
@@ -3459,7 +3564,7 @@ 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;
@@ -3470,8 +3575,8 @@ 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;
        }
@@ -3490,7 +3595,7 @@ 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
@@ -3514,22 +3619,21 @@ 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) {
                printk(KERN_NOTICE "SAK: killed process %d"
                        " (%s): task_session_nr(p)==tty->session\n",
-                       p->pid, p->comm);
+                       task_pid_nr(p), p->comm);
                send_sig(SIGKILL, p, 1);
        } while_each_pid_task(session, PIDTYPE_SID, p);
        /* Now kill any processes that happen to have the
@@ -3539,7 +3643,7 @@ void __do_SAK(struct tty_struct *tty)
                if (p->signal->tty == tty) {
                        printk(KERN_NOTICE "SAK: killed process %d"
                            " (%s): task_session_nr(p)==tty->session\n",
-                           p->pid, p->comm);
+                           task_pid_nr(p), p->comm);
                        send_sig(SIGKILL, p, 1);
                        continue;
                }
@@ -3551,7 +3655,7 @@ 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;
@@ -3559,7 +3663,7 @@ void __do_SAK(struct tty_struct *tty)
                                    filp->private_data == tty) {
                                        printk(KERN_NOTICE "SAK: killed process %d"
                                            " (%s): fd#%d opened to the tty\n",
-                                           p->pid, p->comm, i);
+                                           task_pid_nr(p), p->comm, i);
                                        force_sig(SIGKILL, p);
                                        break;
                                }
@@ -3605,7 +3709,7 @@ 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 =
@@ -3621,7 +3725,8 @@ 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;
@@ -3720,7 +3825,6 @@ static void initialize_tty_struct(struct tty_struct *tty)
        tty->buf.head = tty->buf.tail = NULL;
        tty_buffer_init(tty);
        INIT_DELAYED_WORK(&tty->buf.work, flush_to_ldisc);
-       init_MUTEX(&tty->buf.pty_sem);
        mutex_init(&tty->termios_mutex);
        init_waitqueue_head(&tty->write_wait);
        init_waitqueue_head(&tty->read_wait);
@@ -3728,19 +3832,32 @@ 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 +3912,8 @@ 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 +3940,8 @@ 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 +3953,7 @@ 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 +3967,8 @@ 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 +3985,8 @@ 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 +4004,12 @@ 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 +4079,19 @@ 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 +4134,7 @@ 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;
@@ -4047,10 +4144,6 @@ void __init console_init(void)
        }
 }
 
-#ifdef CONFIG_VT
-extern int vty_init(void);
-#endif
-
 static int __init tty_class_init(void)
 {
        tty_class = class_create(THIS_MODULE, "tty");