* 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.
+ * Rewrote tty_init_dev and tty_release_dev to eliminate races.
* -- Bill Hawes <whawes@star.net>, June 97
*
* Added devfs support.
#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>
#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/seq_file.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
#include <asm/system.h>
#include <linux/kbd_kern.h>
DEFINE_MUTEX(tty_mutex);
EXPORT_SYMBOL(tty_mutex);
-#ifdef CONFIG_UNIX98_PTYS
-extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */
-extern int pty_limit; /* Config limit on Unix98 ptys */
-static DEFINE_IDR(allocated_ptys);
-static DEFINE_MUTEX(allocated_ptys_lock);
-static int ptmx_open(struct inode *, struct file *);
-#endif
-
-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 *,
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,
unsigned long arg);
* Locking: none
*/
-static struct tty_struct *alloc_tty_struct(void)
+struct tty_struct *alloc_tty_struct(void)
{
return kzalloc(sizeof(struct tty_struct), GFP_KERNEL);
}
-static void tty_buffer_free_all(struct tty_struct *);
-
/**
* free_tty_struct - free a disused tty
* @tty: tty struct to free
* Locking: none. Must be called after tty is definitely unused
*/
-static inline void free_tty_struct(struct tty_struct *tty)
+void free_tty_struct(struct tty_struct *tty)
{
kfree(tty->write_buf);
tty_buffer_free_all(tty);
return 0;
}
-/*
- * Tty buffer allocation management
- */
-
-/**
- * tty_buffer_free_all - free buffers used by a tty
- * @tty: tty to free from
- *
- * Remove all the buffers pending on a tty whether queued with data
- * or in the free ring. Must be called when the tty is no longer in use
- *
- * Locking: none
- */
-
-static void tty_buffer_free_all(struct tty_struct *tty)
-{
- struct tty_buffer *thead;
- while ((thead = tty->buf.head) != NULL) {
- tty->buf.head = thead->next;
- kfree(thead);
- }
- while ((thead = tty->buf.free) != NULL) {
- tty->buf.free = thead->next;
- kfree(thead);
- }
- tty->buf.tail = NULL;
- tty->buf.memory_used = 0;
-}
-
-/**
- * tty_buffer_init - prepare a tty buffer structure
- * @tty: tty to initialise
- *
- * Set up the initial state of the buffer management for a tty device.
- * Must be called before the other tty buffer functions are used.
- *
- * Locking: none
- */
-
-static void tty_buffer_init(struct tty_struct *tty)
-{
- spin_lock_init(&tty->buf.lock);
- tty->buf.head = NULL;
- tty->buf.tail = NULL;
- tty->buf.free = NULL;
- tty->buf.memory_used = 0;
-}
-
-/**
- * tty_buffer_alloc - allocate a tty buffer
- * @tty: tty device
- * @size: desired size (characters)
- *
- * Allocate a new tty buffer to hold the desired number of characters.
- * Return NULL if out of memory or the allocation would exceed the
- * per device queue
- *
- * Locking: Caller must hold tty->buf.lock
- */
-
-static struct tty_buffer *tty_buffer_alloc(struct tty_struct *tty, size_t size)
-{
- struct tty_buffer *p;
-
- if (tty->buf.memory_used + size > 65536)
- return NULL;
- p = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC);
- if (p == NULL)
- return NULL;
- p->used = 0;
- p->size = size;
- p->next = NULL;
- p->commit = 0;
- p->read = 0;
- p->char_buf_ptr = (char *)(p->data);
- p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size;
- tty->buf.memory_used += size;
- return p;
-}
-
-/**
- * tty_buffer_free - free a tty buffer
- * @tty: tty owning the buffer
- * @b: the buffer to free
- *
- * Free a tty buffer, or add it to the free list according to our
- * internal strategy
- *
- * Locking: Caller must hold tty->buf.lock
- */
-
-static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b)
-{
- /* Dumb strategy for now - should keep some stats */
- tty->buf.memory_used -= b->size;
- WARN_ON(tty->buf.memory_used < 0);
-
- if (b->size >= 512)
- kfree(b);
- else {
- b->next = tty->buf.free;
- tty->buf.free = b;
- }
-}
-
-/**
- * __tty_buffer_flush - flush full tty buffers
- * @tty: tty to flush
- *
- * flush all the buffers containing receive data. Caller must
- * hold the buffer lock and must have ensured no parallel flush to
- * ldisc is running.
- *
- * Locking: Caller must hold tty->buf.lock
- */
-
-static void __tty_buffer_flush(struct tty_struct *tty)
-{
- struct tty_buffer *thead;
-
- while ((thead = tty->buf.head) != NULL) {
- tty->buf.head = thead->next;
- tty_buffer_free(tty, thead);
- }
- tty->buf.tail = NULL;
-}
-
-/**
- * tty_buffer_flush - flush full tty buffers
- * @tty: tty to flush
- *
- * flush all the buffers containing receive data. If the buffer is
- * being processed by flush_to_ldisc then we defer the processing
- * to that function
- *
- * Locking: none
- */
-
-static void tty_buffer_flush(struct tty_struct *tty)
-{
- unsigned long flags;
- spin_lock_irqsave(&tty->buf.lock, flags);
-
- /* If the data is being pushed to the tty layer then we can't
- process it here. Instead set a flag and the flush_to_ldisc
- path will process the flush request before it exits */
- if (test_bit(TTY_FLUSHING, &tty->flags)) {
- set_bit(TTY_FLUSHPENDING, &tty->flags);
- spin_unlock_irqrestore(&tty->buf.lock, flags);
- wait_event(tty->read_wait,
- test_bit(TTY_FLUSHPENDING, &tty->flags) == 0);
- return;
- } else
- __tty_buffer_flush(tty);
- spin_unlock_irqrestore(&tty->buf.lock, flags);
-}
-
-/**
- * tty_buffer_find - find a free tty buffer
- * @tty: tty owning the buffer
- * @size: characters wanted
- *
- * Locate an existing suitable tty buffer or if we are lacking one then
- * allocate a new one. We round our buffers off in 256 character chunks
- * to get better allocation behaviour.
- *
- * Locking: Caller must hold tty->buf.lock
- */
-
-static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size)
-{
- struct tty_buffer **tbh = &tty->buf.free;
- while ((*tbh) != NULL) {
- struct tty_buffer *t = *tbh;
- if (t->size >= size) {
- *tbh = t->next;
- t->next = NULL;
- t->used = 0;
- t->commit = 0;
- t->read = 0;
- tty->buf.memory_used += t->size;
- return t;
- }
- tbh = &((*tbh)->next);
- }
- /* Round the buffer size out */
- 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 ? */
-}
-
-/**
- * tty_buffer_request_room - grow tty buffer if needed
- * @tty: tty structure
- * @size: size desired
- *
- * Make at least size bytes of linear space available for the tty
- * buffer. If we fail return the size we managed to find.
- *
- * Locking: Takes tty->buf.lock
- */
-int tty_buffer_request_room(struct tty_struct *tty, size_t size)
-{
- struct tty_buffer *b, *n;
- int left;
- unsigned long flags;
-
- spin_lock_irqsave(&tty->buf.lock, flags);
-
- /* OPTIMISATION: We could keep a per tty "zero" sized buffer to
- remove this conditional if its worth it. This would be invisible
- to the callers */
- if ((b = tty->buf.tail) != NULL)
- left = b->size - b->used;
- else
- left = 0;
-
- if (left < size) {
- /* This is the slow path - looking for new buffers to use */
- if ((n = tty_buffer_find(tty, size)) != NULL) {
- if (b != NULL) {
- b->next = n;
- b->commit = b->used;
- } else
- tty->buf.head = n;
- tty->buf.tail = n;
- } else
- size = left;
- }
-
- spin_unlock_irqrestore(&tty->buf.lock, flags);
- return size;
-}
-EXPORT_SYMBOL_GPL(tty_buffer_request_room);
-
-/**
- * tty_insert_flip_string - Add characters to the tty buffer
- * @tty: tty structure
- * @chars: characters
- * @size: size
- *
- * Queue a series of bytes to the tty buffering. All the characters
- * passed are marked as without error. Returns the number added.
- *
- * Locking: Called functions may take tty->buf.lock
- */
-
-int tty_insert_flip_string(struct tty_struct *tty, const unsigned char *chars,
- size_t size)
-{
- int copied = 0;
- do {
- 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))
- break;
- memcpy(tb->char_buf_ptr + tb->used, chars, space);
- memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
- tb->used += space;
- copied += space;
- chars += space;
- /* There is a small chance that we need to split the data over
- several buffers. If this is the case we must loop */
- } while (unlikely(size > copied));
- return copied;
-}
-EXPORT_SYMBOL(tty_insert_flip_string);
-
-/**
- * tty_insert_flip_string_flags - Add characters to the tty buffer
- * @tty: tty structure
- * @chars: characters
- * @flags: flag bytes
- * @size: size
- *
- * Queue a series of bytes to the tty buffering. For each character
- * the flags array indicates the status of the character. Returns the
- * number added.
- *
- * Locking: Called functions may take tty->buf.lock
- */
-
-int tty_insert_flip_string_flags(struct tty_struct *tty,
- const unsigned char *chars, const char *flags, size_t size)
-{
- int copied = 0;
- do {
- 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))
- break;
- memcpy(tb->char_buf_ptr + tb->used, chars, space);
- memcpy(tb->flag_buf_ptr + tb->used, flags, space);
- tb->used += space;
- copied += space;
- chars += space;
- flags += space;
- /* There is a small chance that we need to split the data over
- several buffers. If this is the case we must loop */
- } while (unlikely(size > copied));
- return copied;
-}
-EXPORT_SYMBOL(tty_insert_flip_string_flags);
-
-/**
- * tty_schedule_flip - push characters to ldisc
- * @tty: tty to push from
- *
- * Takes any pending buffers and transfers their ownership to the
- * ldisc side of the queue. It then schedules those characters for
- * processing by the line discipline.
- *
- * Locking: Takes tty->buf.lock
- */
-
-void tty_schedule_flip(struct tty_struct *tty)
-{
- unsigned long flags;
- spin_lock_irqsave(&tty->buf.lock, flags);
- if (tty->buf.tail != NULL)
- tty->buf.tail->commit = tty->buf.tail->used;
- spin_unlock_irqrestore(&tty->buf.lock, flags);
- schedule_delayed_work(&tty->buf.work, 1);
-}
-EXPORT_SYMBOL(tty_schedule_flip);
-
-/**
- * tty_prepare_flip_string - make room for characters
- * @tty: tty
- * @chars: return pointer for character write area
- * @size: desired size
- *
- * Prepare a block of space in the buffer for data. Returns the length
- * available and buffer pointer to the space which is now allocated and
- * accounted for as ready for normal characters. This is used for drivers
- * that need their own block copy routines into the buffer. There is no
- * guarantee the buffer is a DMA target!
- *
- * Locking: May call functions taking tty->buf.lock
- */
-
-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)) {
- struct tty_buffer *tb = tty->buf.tail;
- *chars = tb->char_buf_ptr + tb->used;
- memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space);
- tb->used += space;
- }
- return space;
-}
-
-EXPORT_SYMBOL_GPL(tty_prepare_flip_string);
-
-/**
- * tty_prepare_flip_string_flags - make room for characters
- * @tty: tty
- * @chars: return pointer for character write area
- * @flags: return pointer for status flag write area
- * @size: desired size
- *
- * Prepare a block of space in the buffer for data. Returns the length
- * available and buffer pointer to the space which is now allocated and
- * accounted for as ready for characters. This is used for drivers
- * that need their own block copy routines into the buffer. There is no
- * guarantee the buffer is a DMA target!
- *
- * 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 space = tty_buffer_request_room(tty, size);
- if (likely(space)) {
- struct tty_buffer *tb = tty->buf.tail;
- *chars = tb->char_buf_ptr + tb->used;
- *flags = tb->flag_buf_ptr + tb->used;
- tb->used += space;
- }
- return space;
-}
-
-EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags);
-
-
-
-/**
- * tty_set_termios_ldisc - set ldisc field
- * @tty: tty structure
- * @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
- * any harm.
- *
- * Locking: takes termios_mutex
- */
-
-static void tty_set_termios_ldisc(struct tty_struct *tty, int num)
-{
- mutex_lock(&tty->termios_mutex);
- tty->termios->c_line = num;
- mutex_unlock(&tty->termios_mutex);
-}
-
-/*
- * 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);
-/* Line disc dispatch table */
-static struct tty_ldisc tty_ldiscs[NR_LDISCS];
-
-/**
- * tty_register_ldisc - install a line discipline
- * @disc: ldisc number
- * @new_ldisc: pointer to the ldisc object
- *
- * Installs a new line discipline into the kernel. The discipline
- * is set up as unreferenced and then made available to the kernel
- * from this point onwards.
- *
- * Locking:
- * takes tty_ldisc_lock to guard against ldisc races
- */
-
-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);
-
-/**
- * tty_unregister_ldisc - unload a line discipline
- * @disc: ldisc number
- * @new_ldisc: pointer to the ldisc object
- *
- * Remove a line discipline from the kernel providing it is not
- * currently in use.
- *
- * Locking:
- * takes tty_ldisc_lock to guard against ldisc races
- */
-
-int tty_unregister_ldisc(int disc)
-{
- unsigned long flags;
- int ret = 0;
-
- if (disc < N_TTY || disc >= NR_LDISCS)
- return -EINVAL;
-
- spin_lock_irqsave(&tty_ldisc_lock, flags);
- 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_unregister_ldisc);
-
-/**
- * tty_ldisc_get - take a reference to an ldisc
- * @disc: ldisc number
- *
- * Takes a reference to a line discipline. Deals with refcounts and
- * module locking counts. Returns NULL if the discipline is not available.
- * Returns a pointer to the discipline and bumps the ref count if it is
- * available
- *
- * Locking:
- * takes tty_ldisc_lock to guard against ldisc races
- */
-
-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);
-
-/**
- * tty_ldisc_put - drop ldisc reference
- * @disc: ldisc number
- *
- * Drop a reference to a line discipline. Manage refcounts and
- * module usage counts
- *
- * Locking:
- * takes tty_ldisc_lock to guard against ldisc races
- */
-
-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);
- ld->refcount--;
- module_put(ld->owner);
- spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-}
-
-EXPORT_SYMBOL_GPL(tty_ldisc_put);
-
-/**
- * tty_ldisc_assign - set ldisc on a tty
- * @tty: tty to assign
- * @ld: line discipline
- *
- * Install an instance of a line discipline into a tty structure. The
- * ldisc must have a reference count above zero to ensure it remains/
- * The tty instance refcount starts at zero.
- *
- * Locking:
- * Caller must hold references
- */
-
-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
- *
- * Locking: takes tty_ldisc_lock
- */
-
-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)
- *
- * 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)
- 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.
- *
- * Locking: called functions take tty_ldisc_lock
- */
-
-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.
- *
- * 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)
- 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 necessary 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.
- *
- * Locking: takes tty_ldisc_lock.
- * called functions take termios_mutex
- */
-
-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;
- struct tty_struct *o_tty;
-
- if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS))
- return -EINVAL;
-
-restart:
-
- 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;
-
- /*
- * Problem: What do we do if this blocks ?
- */
-
- tty_wait_until_sent(tty, 0);
-
- if (tty->ldisc.num == ldisc) {
- tty_ldisc_put(ldisc);
- return 0;
- }
-
- /*
- * No more input please, we are switching. The new ldisc
- * will update this value in the ldisc open function
- */
-
- tty->receive_room = 0;
-
- o_ldisc = tty->ldisc;
- o_tty = tty->link;
-
- /*
- * 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 || (o_tty && o_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);
- 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;
- }
- 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)
- return -ERESTARTSYS;
- goto restart;
- }
- }
- /*
- * 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);
- ld = tty_ldisc_ref_wait(tty);
- tty_ldisc_deref(ld);
- goto restart;
- }
-
- clear_bit(TTY_LDISC, &tty->flags);
- if (o_tty)
- clear_bit(TTY_LDISC, &o_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->buf.work);
- /*
- * Wait for ->hangup_work and ->buf.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);
- if (o_tty)
- tty_ldisc_enable(o_tty);
-
- /* Restart it in case no characters kick it off. Safe if
- already running */
- if (work)
- schedule_delayed_work(&tty->buf.work, 1);
- return retval;
-}
-
/**
* get_tty_driver - find device of a tty
* @dev_t: device identifier
if (device < base || device >= base + p->num)
continue;
*index = device - base;
- return p;
+ return tty_driver_kref_get(p);
}
return NULL;
}
{
struct tty_driver *p, *res = NULL;
int tty_line = 0;
+ int len;
char *str;
+ for (str = name; *str; str++)
+ if ((*str >= '0' && *str <= '9') || *str == ',')
+ break;
+ if (!*str)
+ return NULL;
+
+ len = str - name;
+ tty_line = simple_strtoul(str, &str, 10);
+
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 (strncmp(name, p->name, len) != 0)
+ continue;
if (*str == ',')
str++;
if (*str == '\0')
- str = 0;
-
- if (tty_line >= 0 && tty_line <= p->num && p->poll_init &&
- !p->poll_init(p, tty_line, str)) {
+ str = NULL;
- res = p;
+ if (tty_line >= 0 && tty_line <= p->num && p->ops &&
+ p->ops->poll_init && !p->ops->poll_init(p, tty_line, str)) {
+ res = tty_driver_kref_get(p);
*line = tty_line;
break;
}
* 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)
{
+ 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);
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;
}
.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,
.fasync = tty_fasync,
};
-#ifdef CONFIG_UNIX98_PTYS
-static const struct file_operations ptmx_fops = {
- .llseek = no_llseek,
- .read = tty_read,
- .write = tty_write,
- .poll = tty_poll,
- .ioctl = tty_ioctl,
- .compat_ioctl = tty_compat_ioctl,
- .open = ptmx_open,
- .release = tty_release,
- .fasync = tty_fasync,
-};
-#endif
-
static const struct file_operations console_fops = {
.llseek = no_llseek,
.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,
.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,
};
if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) {
ld = tty_ldisc_ref(tty);
if (ld) {
- if (ld->write_wakeup)
- ld->write_wakeup(tty);
+ if (ld->ops->write_wakeup)
+ ld->ops->write_wakeup(tty);
tty_ldisc_deref(ld);
}
}
{
struct tty_ldisc *ld = tty_ldisc_ref(tty);
if (ld) {
- if (ld->flush_buffer)
- ld->flush_buffer(tty);
+ if (ld->ops->flush_buffer)
+ ld->ops->flush_buffer(tty);
tty_ldisc_deref(ld);
}
tty_buffer_flush(tty);
struct task_struct *p;
struct tty_ldisc *ld;
int closecount = 0, n;
+ unsigned long flags;
+ int refs = 0;
if (!tty)
return;
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 (ld->ops->flush_buffer)
+ ld->ops->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);
+ ld->ops->write_wakeup)
+ ld->ops->write_wakeup(tty);
+ if (ld->ops->hangup)
+ ld->ops->hangup(tty);
}
/*
* FIXME: Once we trust the LDISC code better we can wait here for
if (tty->session) {
do_each_pid_task(tty->session, PIDTYPE_SID, p) {
spin_lock_irq(&p->sighand->siglock);
- if (p->signal->tty == tty)
+ if (p->signal->tty == tty) {
p->signal->tty = NULL;
+ /* We defer the dereferences outside fo
+ the tasklist lock */
+ refs++;
+ }
if (!p->signal->leader) {
spin_unlock_irq(&p->sighand->siglock);
continue;
__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);
+
+ /* Account for the p->signal references we killed */
+ while (refs--)
+ tty_kref_put(tty);
+
/*
* If one of the devices matches a console pointer, we
* cannot just call hangup() because that will cause
* 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);
+ 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
EXPORT_SYMBOL(tty_vhangup);
/**
- * tty_hung_up_p - was tty hung up
- * @filp: file pointer of tty
+ * tty_vhangup_self - process vhangup for own ctty
*
- * Return true if the tty has been subject to a vhangup or a carrier
- * loss
+ * Perform a vhangup on the current controlling tty
*/
-int tty_hung_up_p(struct file *filp)
+void tty_vhangup_self(void)
{
- return (filp->f_op == &hung_up_tty_fops);
-}
+ struct tty_struct *tty;
-EXPORT_SYMBOL(tty_hung_up_p);
+ tty = get_current_tty();
+ if (tty) {
+ tty_vhangup(tty);
+ tty_kref_put(tty);
+ }
+}
/**
- * is_tty - checker whether file is a TTY
- * @filp: file handle that may be a tty
+ * tty_hung_up_p - was tty hung up
+ * @filp: file pointer of tty
*
- * Check if the file handle is a tty handle.
+ * Return true if the tty has been subject to a vhangup or a carrier
+ * loss
*/
-int is_tty(struct file *filp)
+int tty_hung_up_p(struct file *filp)
{
- return filp->f_op->read == tty_read
- || filp->f_op->read == hung_up_tty_read;
+ return (filp->f_op == &hung_up_tty_fops);
}
+EXPORT_SYMBOL(tty_hung_up_p);
+
static void session_clear_tty(struct pid *session)
{
struct task_struct *p;
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);
- /* XXX: here we race, there is nothing protecting tty */
+ lock_kernel();
if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY)
tty_vhangup(tty);
+ unlock_kernel();
+ tty_kref_put(tty);
} else if (on_exit) {
struct pid *old_pgrp;
spin_lock_irq(¤t->sighand->siglock);
kill_pgrp(old_pgrp, SIGCONT, on_exit);
put_pid(old_pgrp);
}
- mutex_unlock(&tty_mutex);
- unlock_kernel();
return;
}
if (tty_pgrp) {
current->signal->tty_old_pgrp = NULL;
spin_unlock_irq(¤t->sighand->siglock);
- mutex_lock(&tty_mutex);
- /* 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);
+ tty_kref_put(tty);
} else {
#ifdef TTY_DEBUG_HANGUP
printk(KERN_DEBUG "error attempted to write to tty [0x%p]"
" = NULL", tty);
#endif
}
- mutex_unlock(&tty_mutex);
/* Now clear signal->tty under the lock */
read_lock(&tasklist_lock);
session_clear_tty(task_session(current));
read_unlock(&tasklist_lock);
- unlock_kernel();
}
/**
void no_tty(void)
{
struct task_struct *tsk = current;
+ lock_kernel();
if (tsk->signal->leader)
disassociate_ctty(0);
+ unlock_kernel();
proc_clear_tty(tsk);
}
* 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);
* 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);
}
* 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,
/* 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);
+ if (ld->ops->read)
+ i = (ld->ops->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;
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;
return ret;
}
+/**
+ * tty_write_message - write a message to a certain tty, not just the console.
+ * @tty: the destination tty_struct
+ * @msg: the message to write
+ *
+ * This is used for messages that need to be redirected to a specific tty.
+ * We don't put it into the syslog queue right now maybe in the future if
+ * really needed.
+ *
+ * We must still hold the BKL and test the CLOSING flag for the moment.
+ */
+
+void tty_write_message(struct tty_struct *tty, char *msg)
+{
+ lock_kernel();
+ if (tty) {
+ mutex_lock(&tty->atomic_write_lock);
+ if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags))
+ tty->ops->write(tty, msg, strlen(msg));
+ tty_write_unlock(tty);
+ }
+ unlock_kernel();
+ return;
+}
+
/**
* tty_write - write method for tty device file
tty = (struct tty_struct *)file->private_data;
if (tty_paranoia_check(tty, inode, "tty_write"))
return -EIO;
- if (!tty || !tty->driver->write ||
+ 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)
+ if (!ld->ops->write)
ret = -EIO;
else
- ret = do_tty_write(ld->write, tty, file, buf, count);
+ ret = do_tty_write(ld->ops->write, tty, file, buf, count);
tty_ldisc_deref(ld);
return ret;
}
}
/**
- * pty_line_name - generate name for a tty
+ * tty_line_name - generate name for a tty
* @driver: the tty driver in use
* @index: the minor number
* @p: output buffer of at least 7 bytes
}
/**
- * init_dev - initialise a tty device
+ * tty_driver_lookup_tty() - find an existing tty, if any
+ * @driver: the driver for the tty
+ * @idx: the minor number
+ *
+ * Return the tty, if found or ERR_PTR() otherwise.
+ *
+ * Locking: tty_mutex must be held. If tty is found, the mutex must
+ * be held until the 'fast-open' is also done. Will change once we
+ * have refcounting in the driver and per driver locking
+ */
+struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver,
+ struct inode *inode, int idx)
+{
+ struct tty_struct *tty;
+
+ if (driver->ops->lookup)
+ return driver->ops->lookup(driver, inode, idx);
+
+ tty = driver->ttys[idx];
+ return tty;
+}
+
+/**
+ * tty_init_termios - helper for termios setup
+ * @tty: the tty to set up
+ *
+ * Initialise the termios structures for this tty. Thus runs under
+ * the tty_mutex currently so we can be relaxed about ordering.
+ */
+
+int tty_init_termios(struct tty_struct *tty)
+{
+ struct ktermios *tp, *ltp;
+ int idx = tty->index;
+
+ tp = tty->driver->termios[idx];
+ ltp = tty->driver->termios_locked[idx];
+ if (tp == NULL) {
+ WARN_ON(ltp != NULL);
+ tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
+ ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL);
+ if (tp == NULL || ltp == NULL) {
+ kfree(tp);
+ kfree(ltp);
+ return -ENOMEM;
+ }
+ memcpy(tp, &tty->driver->init_termios,
+ sizeof(struct ktermios));
+ tty->driver->termios[idx] = tp;
+ tty->driver->termios_locked[idx] = ltp;
+ }
+ tty->termios = tp;
+ tty->termios_locked = ltp;
+
+ /* Compatibility until drivers always set this */
+ tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
+ tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
+ return 0;
+}
+
+/**
+ * tty_driver_install_tty() - install a tty entry in the driver
+ * @driver: the driver for the tty
+ * @tty: the tty
+ *
+ * Install a tty object into the driver tables. The tty->index field
+ * will be set by the time this is called. This method is responsible
+ * for ensuring any need additional structures are allocated and
+ * configured.
+ *
+ * Locking: tty_mutex for now
+ */
+static int tty_driver_install_tty(struct tty_driver *driver,
+ struct tty_struct *tty)
+{
+ int idx = tty->index;
+
+ if (driver->ops->install)
+ return driver->ops->install(driver, tty);
+
+ if (tty_init_termios(tty) == 0) {
+ tty_driver_kref_get(driver);
+ tty->count++;
+ driver->ttys[idx] = tty;
+ return 0;
+ }
+ return -ENOMEM;
+}
+
+/**
+ * tty_driver_remove_tty() - remove a tty from the driver tables
+ * @driver: the driver for the tty
+ * @idx: the minor number
+ *
+ * Remvoe a tty object from the driver tables. The tty->index field
+ * will be set by the time this is called.
+ *
+ * Locking: tty_mutex for now
+ */
+static void tty_driver_remove_tty(struct tty_driver *driver,
+ struct tty_struct *tty)
+{
+ if (driver->ops->remove)
+ driver->ops->remove(driver, tty);
+ else
+ driver->ttys[tty->index] = NULL;
+}
+
+/*
+ * tty_reopen() - fast re-open of an open tty
+ * @tty - the tty to open
+ *
+ * Return 0 on success, -errno on error.
+ *
+ * Locking: tty_mutex must be held from the time the tty was found
+ * till this open completes.
+ */
+static int tty_reopen(struct tty_struct *tty)
+{
+ struct tty_driver *driver = tty->driver;
+
+ if (test_bit(TTY_CLOSING, &tty->flags))
+ return -EIO;
+
+ 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)
+ return -EIO;
+
+ tty->link->count++;
+ }
+ tty->count++;
+ tty->driver = driver; /* N.B. why do this every time?? */
+
+ WARN_ON(!test_bit(TTY_LDISC, &tty->flags));
+
+ return 0;
+}
+
+/**
+ * tty_init_dev - initialise a tty device
* @driver: tty driver we are opening a device on
* @idx: device index
- * @tty: returned tty structure
+ * @ret_tty: returned tty structure
+ * @first_ok: ok to open a new device (used by ptmx)
*
* Prepare a tty device. This may not be a "new" clean device but
* could also be an active device. The pty drivers require special
* 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_init_dev(struct tty_driver *driver, int idx,
+ int first_ok)
{
- struct tty_struct *tty, *o_tty;
- struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc;
- struct ktermios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc;
- int retval = 0;
+ struct tty_struct *tty;
+ int retval;
- /* check whether we're reopening an existing tty */
- if (driver->flags & TTY_DRIVER_DEVPTS_MEM) {
- tty = devpts_get_tty(idx);
- /*
- * If we don't have a tty here on a slave open, it's because
- * the master already started the close process and there's
- * no relation between devpts file and tty anymore.
- */
- if (!tty && driver->subtype == PTY_TYPE_SLAVE) {
- retval = -EIO;
- goto end_init;
- }
- /*
- * It's safe from now on because init_dev() is called with
- * tty_mutex held and release_dev() won't change tty->count
- * or tty->flags without having to grab tty_mutex
- */
- if (tty && driver->subtype == PTY_TYPE_MASTER)
- tty = tty->link;
- } else {
- tty = driver->ttys[idx];
- }
- if (tty) goto fast_track;
+ /* Check if pty master is being opened multiple times */
+ if (driver->subtype == PTY_TYPE_MASTER &&
+ (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok)
+ return ERR_PTR(-EIO);
/*
* First time open is complex, especially for PTY devices.
* 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;
+ if (!try_module_get(driver->owner))
+ return ERR_PTR(-ENODEV);
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 = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
- if (!tp)
- goto free_mem_out;
- *tp = driver->init_termios;
- }
-
- if (!*ltp_loc) {
- ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL);
- if (!ltp)
- goto free_mem_out;
- }
-
- 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];
- }
+ initialize_tty_struct(tty, driver, idx);
- if (!*o_tp_loc) {
- o_tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
- if (!o_tp)
- goto free_mem_out;
- *o_tp = driver->other->init_termios;
- }
-
- if (!*o_ltp_loc) {
- o_ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL);
- if (!o_ltp)
- goto free_mem_out;
- }
-
- /*
- * 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;
+ retval = tty_driver_install_tty(driver, tty);
+ if (retval < 0) {
+ free_tty_struct(tty);
+ module_put(driver->owner);
+ return ERR_PTR(retval);
}
/*
- * 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))
- 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;
- /* Compatibility until drivers always set this */
- tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
- tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
- 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.
*/
- 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 mutex */
-end_init:
- return retval;
-
- /* Release locally allocated memory ... nothing placed in slots */
-free_mem_out:
- kfree(o_tp);
- if (o_tty)
- free_tty_struct(o_tty);
- kfree(ltp);
- kfree(tp);
- free_tty_struct(tty);
+ retval = tty_ldisc_setup(tty, tty->link);
+ if (retval)
+ goto release_mem_out;
+ return tty;
fail_no_mem:
module_put(driver->owner);
- retval = -ENOMEM;
- goto end_init;
+ return ERR_PTR(-ENOMEM);
/* call the tty release_tty routine to clean out this slot */
release_mem_out:
if (printk_ratelimit())
- printk(KERN_INFO "init_dev: ldisc open failed, "
+ printk(KERN_INFO "tty_init_dev: ldisc open failed, "
"clearing slot %d\n", idx);
release_tty(tty, idx);
- goto end_init;
+ return ERR_PTR(retval);
+}
+
+void tty_free_termios(struct tty_struct *tty)
+{
+ struct ktermios *tp;
+ int idx = tty->index;
+ /* Kill this flag and push into drivers for locking etc */
+ if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
+ /* FIXME: Locking on ->termios array */
+ tp = tty->termios;
+ tty->driver->termios[idx] = NULL;
+ kfree(tp);
+
+ tp = tty->termios_locked;
+ tty->driver->termios_locked[idx] = NULL;
+ kfree(tp);
+ }
+}
+EXPORT_SYMBOL(tty_free_termios);
+
+void tty_shutdown(struct tty_struct *tty)
+{
+ tty_driver_remove_tty(tty->driver, tty);
+ tty_free_termios(tty);
}
+EXPORT_SYMBOL(tty_shutdown);
/**
* release_one_tty - release tty structure memory
+ * @kref: kref of tty we are obliterating
*
* Releases memory associated with a tty structure, and clears out the
* driver table slots. This function is called when a device is no longer
* tty_mutex - sometimes only
* takes the file list lock internally when working on the list
* of ttys that the driver keeps.
- * FIXME: should we require tty_mutex is held here ??
*/
-static void release_one_tty(struct tty_struct *tty, int idx)
+static void release_one_tty(struct kref *kref)
{
- int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM;
- struct ktermios *tp;
-
- 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);
- }
-
+ struct tty_struct *tty = container_of(kref, struct tty_struct, kref);
+ struct tty_driver *driver = tty->driver;
+ if (tty->ops->shutdown)
+ tty->ops->shutdown(tty);
+ else
+ tty_shutdown(tty);
tty->magic = 0;
- tty->driver->refcount--;
+ tty_driver_kref_put(driver);
+ module_put(driver->owner);
file_list_lock();
list_del_init(&tty->tty_files);
}
/**
+ * tty_kref_put - release a tty kref
+ * @tty: tty device
+ *
+ * Release a reference to a tty device and if need be let the kref
+ * layer destruct the object for us
+ */
+
+void tty_kref_put(struct tty_struct *tty)
+{
+ if (tty)
+ kref_put(&tty->kref, release_one_tty);
+}
+EXPORT_SYMBOL(tty_kref_put);
+
+/**
* release_tty - release tty structure memory
*
* Release both @tty and a possible linked partner (think pty pair),
* takes the file list lock internally when working on the list
* of ttys that the driver keeps.
* FIXME: should we require tty_mutex is held here ??
+ *
*/
static void release_tty(struct tty_struct *tty, int idx)
{
- struct tty_driver *driver = tty->driver;
+ /* This should always be true but check for the moment */
+ WARN_ON(tty->index != idx);
if (tty->link)
- release_one_tty(tty->link, idx);
- release_one_tty(tty, idx);
- module_put(driver->owner);
+ tty_kref_put(tty->link);
+ tty_kref_put(tty);
}
/*
* 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)
+void tty_release_dev(struct file *filp)
{
struct tty_struct *tty, *o_tty;
int pty_master, tty_closing, o_tty_closing, do_sleep;
int devpts;
int idx;
char buf[64];
- unsigned long flags;
+ struct inode *inode;
+ inode = filp->f_path.dentry->d_inode;
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, inode, "tty_release_dev"))
return;
- check_tty_count(tty, "release_dev");
+ check_tty_count(tty, "tty_release_dev");
tty_fasync(-1, filp, 0);
#ifdef TTY_PARANOIA_CHECK
if (idx < 0 || idx >= tty->driver->num) {
- printk(KERN_DEBUG "release_dev: bad idx when trying to "
+ printk(KERN_DEBUG "tty_release_dev: bad idx when trying to "
"free (%s)\n", tty->name);
return;
}
- if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) {
+ if (!devpts) {
if (tty != tty->driver->ttys[idx]) {
- printk(KERN_DEBUG "release_dev: driver.table[%d] not tty "
+ printk(KERN_DEBUG "tty_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 "
+ printk(KERN_DEBUG "tty_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 "
+ printk(KERN_DEBUG "tty_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)...",
+ printk(KERN_DEBUG "tty_release_dev of %s (tty count=%d)...",
tty_name(tty, buf), tty->count);
#endif
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] "
+ printk(KERN_DEBUG "tty_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] "
+ printk(KERN_DEBUG "tty_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["
+ printk(KERN_DEBUG "tty_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");
+ printk(KERN_DEBUG "tty_release_dev: bad pty pointers\n");
return;
}
}
#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
if (!do_sleep)
break;
- printk(KERN_WARNING "release_dev: %s: read/write wait queue "
+ printk(KERN_WARNING "tty_release_dev: %s: read/write wait queue "
"active!\n", tty_name(tty, buf));
mutex_unlock(&tty_mutex);
schedule();
*/
if (pty_master) {
if (--o_tty->count < 0) {
- printk(KERN_WARNING "release_dev: bad pty slave count "
+ printk(KERN_WARNING "tty_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",
+ printk(KERN_WARNING "tty_release_dev: bad tty->count (%d) for %s\n",
tty->count, tty_name(tty, buf));
tty->count = 0;
}
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);
- cancel_delayed_work(&tty->buf.work);
-
- /*
- * 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) {
- 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
+ * Ask the line discipline code to release its structures
*/
- 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);
- }
+ tty_ldisc_release(tty, o_tty);
/*
* The release_tty function takes care of the details of clearing
* the slots and preserving the termios structure.
*/
release_tty(tty, idx);
-#ifdef CONFIG_UNIX98_PTYS
/* Make this pty number available for reallocation */
- if (devpts) {
- mutex_lock(&allocated_ptys_lock);
- idr_remove(&allocated_ptys, idx);
- mutex_unlock(&allocated_ptys_lock);
- }
-#endif
-
+ if (devpts)
+ devpts_kill_index(inode, idx);
}
/**
- * tty_open - open a tty device
+ * __tty_open - open a tty device
* @inode: inode of device file
* @filp: file pointer to tty
*
* The termios state of a pty is reset on first open so that
* settings don't persist across reuse.
*
- * Locking: tty_mutex protects tty, get_tty_driver and init_dev work.
+ * Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work.
* tty->count should protect the rest.
* ->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;
+ struct tty_struct *tty = NULL;
int noctty, retval;
struct tty_driver *driver;
int index;
mutex_unlock(&tty_mutex);
return -ENXIO;
}
- driver = tty->driver;
+ driver = tty_driver_kref_get(tty->driver);
index = tty->index;
filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */
/* noctty = 1; */
+ /* FIXME: Should we take a driver reference ? */
+ tty_kref_put(tty);
goto got_driver;
}
#ifdef CONFIG_VT
if (device == MKDEV(TTY_MAJOR, 0)) {
extern struct tty_driver *console_driver;
- driver = console_driver;
+ driver = tty_driver_kref_get(console_driver);
index = fg_console;
noctty = 1;
goto got_driver;
}
#endif
if (device == MKDEV(TTYAUX_MAJOR, 1)) {
- driver = console_device(&index);
+ driver = tty_driver_kref_get(console_device(&index));
if (driver) {
/* Don't let /dev/console block */
filp->f_flags |= O_NONBLOCK;
return -ENODEV;
}
got_driver:
- retval = init_dev(driver, index, &tty);
+ if (!tty) {
+ /* check whether we're reopening an existing tty */
+ tty = tty_driver_lookup_tty(driver, inode, index);
+
+ if (IS_ERR(tty))
+ return PTR_ERR(tty);
+ }
+
+ if (tty) {
+ retval = tty_reopen(tty);
+ if (retval)
+ tty = ERR_PTR(retval);
+ } else
+ tty = tty_init_dev(driver, index, 0);
+
mutex_unlock(&tty_mutex);
- if (retval)
- return retval;
+ tty_driver_kref_put(driver);
+ if (IS_ERR(tty))
+ return PTR_ERR(tty);
filp->private_data = tty;
file_move(filp, &tty->tty_files);
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;
}
printk(KERN_DEBUG "error %d in opening %s...", retval,
tty->name);
#endif
- release_dev(filp);
+ tty_release_dev(filp);
if (retval != -ERESTARTSYS)
return retval;
if (signal_pending(current))
return 0;
}
-#ifdef CONFIG_UNIX98_PTYS
-/**
- * ptmx_open - open a unix 98 pty master
- * @inode: inode of device file
- * @filp: file pointer to tty
- *
- * Allocate a unix98 pty master device from the ptmx driver.
- *
- * Locking: tty_mutex protects theinit_dev work. tty->count should
- * protect the rest.
- * allocated_ptys_lock handles the list of free pty numbers
- */
-
-static int ptmx_open(struct inode *inode, struct file *filp)
+/* BKL pushdown: scary code avoidance wrapper */
+static int tty_open(struct inode *inode, struct file *filp)
{
- struct tty_struct *tty;
- int retval;
- int index;
- int idr_ret;
-
- nonseekable_open(inode, filp);
-
- /* find a device that is not in use. */
- mutex_lock(&allocated_ptys_lock);
- if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) {
- mutex_unlock(&allocated_ptys_lock);
- return -ENOMEM;
- }
- idr_ret = idr_get_new(&allocated_ptys, NULL, &index);
- if (idr_ret < 0) {
- mutex_unlock(&allocated_ptys_lock);
- if (idr_ret == -EAGAIN)
- return -ENOMEM;
- return -EIO;
- }
- if (index >= pty_limit) {
- idr_remove(&allocated_ptys, index);
- mutex_unlock(&allocated_ptys_lock);
- return -EIO;
- }
- mutex_unlock(&allocated_ptys_lock);
-
- mutex_lock(&tty_mutex);
- retval = init_dev(ptm_driver, index, &tty);
- mutex_unlock(&tty_mutex);
+ int ret;
- if (retval)
- goto out;
+ lock_kernel();
+ ret = __tty_open(inode, filp);
+ unlock_kernel();
+ return ret;
+}
- 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);
- return retval;
-out:
- mutex_lock(&allocated_ptys_lock);
- idr_remove(&allocated_ptys, index);
- mutex_unlock(&allocated_ptys_lock);
- return retval;
-}
-#endif
/**
* tty_release - vfs callback for close
* this tty. There may however be several such references.
*
* Locking:
- * Takes bkl. See release_dev
+ * Takes bkl. See tty_release_dev
*/
static int tty_release(struct inode *inode, struct file *filp)
{
lock_kernel();
- release_dev(filp);
+ tty_release_dev(filp);
unlock_kernel();
return 0;
}
return 0;
ld = tty_ldisc_ref_wait(tty);
- if (ld->poll)
- ret = (ld->poll)(tty, filp, wait);
+ if (ld->ops->poll)
+ ret = (ld->ops->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;
+ unsigned long flags;
+ int retval = 0;
+ lock_kernel();
tty = (struct tty_struct *)filp->private_data;
if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync"))
- return 0;
+ goto out;
retval = fasync_helper(fd, filp, on, &tty->fasync);
if (retval <= 0)
- return retval;
+ goto out;
if (on) {
enum pid_type type;
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;
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;
+ goto out;
} else {
if (!tty->fasync && !waitqueue_active(&tty->read_wait))
tty->minimum_to_wake = N_TTY_BUF_SIZE;
}
- return 0;
+ retval = 0;
+out:
+ unlock_kernel();
+ return retval;
}
/**
if (get_user(ch, p))
return -EFAULT;
ld = tty_ldisc_ref_wait(tty);
- ld->receive_buf(tty, &ch, &mbz, 1);
+ ld->ops->receive_buf(tty, &ch, &mbz, 1);
tty_ldisc_deref(ld);
return 0;
}
}
/**
+ * tty_do_resize - resize event
+ * @tty: tty being resized
+ * @real_tty: real tty (not the same as tty if using a pty/tty pair)
+ * @rows: rows (character)
+ * @cols: cols (character)
+ *
+ * Update the termios variables and send the neccessary signals to
+ * peform a terminal resize correctly
+ */
+
+int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty,
+ struct winsize *ws)
+{
+ struct pid *pgrp, *rpgrp;
+ unsigned long flags;
+
+ /* For a PTY we need to lock the tty side */
+ mutex_lock(&real_tty->termios_mutex);
+ if (!memcmp(ws, &real_tty->winsize, sizeof(*ws)))
+ goto done;
+ /* 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 = *ws;
+ real_tty->winsize = *ws;
+done:
+ mutex_unlock(&real_tty->termios_mutex);
+ return 0;
+}
+
+/**
* tiocswinsz - implement window size set ioctl
* @tty; tty
* @arg: user buffer for result
* actually has driver level meaning and triggers a VC resize.
*
* Locking:
- * Called function use the console_sem is used to ensure we do
- * not try and resize the console twice at once.
- * The tty->termios_mutex is used to ensure we don't double
- * resize and get confused. Lock order - tty->termios_mutex before
- * console sem
+ * Driver dependant. The default do_resize method takes the
+ * tty termios mutex and ctrl_lock. The console takes its own lock
+ * then calls into the default method.
*/
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;
- mutex_lock(&tty->termios_mutex);
- if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg)))
- goto done;
-
-#ifdef CONFIG_VT
- if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) {
- if (vc_lock_resize(tty->driver_data, tmp_ws.ws_col,
- tmp_ws.ws_row)) {
- mutex_unlock(&tty->termios_mutex);
- 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);
- tty->winsize = tmp_ws;
- real_tty->winsize = tmp_ws;
-done:
- mutex_unlock(&tty->termios_mutex);
- return 0;
+ if (tty->ops->resize)
+ return tty->ops->resize(tty, real_tty, &tmp_ws);
+ else
+ return tty_do_resize(tty, real_tty, &tmp_ws);
}
/**
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;
}
}
/**
+ * 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
static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p)
{
+ struct pid *pid;
+ int ret;
/*
* (tty == real_tty) is a cheap way of
* testing if the tty is NOT a master pty.
*/
if (tty == real_tty && current->signal->tty != real_tty)
return -ENOTTY;
- return put_user(pid_vnr(real_tty->pgrp), p);
+ pid = tty_get_pgrp(real_tty);
+ ret = put_user(pid_vnr(pid), p);
+ put_pid(pid);
+ return ret;
}
/**
* 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)
struct pid *pgrp;
pid_t pgrp_nr;
int retval = tty_check_change(real_tty);
+ unsigned long flags;
if (retval == -EIO)
return -ENOTTY;
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;
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;
}
/**
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);
- if (!signal_pending(current))
- msleep_interruptible(duration);
- tty->driver->break_ctl(tty, 0);
- tty_write_unlock(tty);
- if (signal_pending(current))
- return -EINTR;
- return 0;
+ int retval;
+
+ if (tty->ops->break_ctl == NULL)
+ return 0;
+
+ if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK)
+ retval = tty->ops->break_ctl(tty, duration);
+ else {
+ /* Do the work ourselves */
+ if (tty_write_lock(tty, 0) < 0)
+ return -EINTR;
+ retval = tty->ops->break_ctl(tty, -1);
+ if (retval)
+ goto out;
+ if (!signal_pending(current))
+ msleep_interruptible(duration);
+ retval = tty->ops->break_ctl(tty, 0);
+out:
+ tty_write_unlock(tty);
+ if (signal_pending(current))
+ retval = -EINTR;
+ }
+ return retval;
}
/**
- * tiocmget - get modem status
+ * tty_tiocmget - get modem status
* @tty: tty device
* @file: user file pointer
* @p: pointer to result
{
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);
}
/**
- * 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
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;
- }
+ int retval;
+ unsigned int set, clear, val;
- set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
- clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
+ if (tty->ops->tiocmset == NULL)
+ return -EINVAL;
- retval = tty->driver->tiocmset(tty, file, set, clear);
+ 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;
}
- return retval;
+ set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
+ clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
+ return tty->ops->tiocmset(tty, file, set, clear);
}
/*
* 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)
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
break;
}
+ /*
+ * Now do the stuff.
+ */
switch (cmd) {
case TIOCSTI:
return tiocsti(tty, p);
case TIOCGWINSZ:
- return tiocgwinsz(tty, p);
+ return tiocgwinsz(real_tty, p);
case TIOCSWINSZ:
return tiocswinsz(tty, real_tty, p);
case TIOCCONS:
case TIOCGSID:
return tiocgsid(tty, real_tty, p);
case TIOCGETD:
- /* FIXME: check this is ok */
- return put_user(tty->ldisc.num, (int __user *)p);
+ return put_user(tty->ldisc.ops->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);
+ if (tty->ops->break_ctl)
+ return tty->ops->break_ctl(tty, -1);
return 0;
-
case TIOCCBRK: /* Turn break off, unconditionally */
- tty->driver->break_ctl(tty, 0);
+ if (tty->ops->break_ctl)
+ return 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
}
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;
}
ld = tty_ldisc_ref_wait(tty);
retval = -EINVAL;
- if (ld->ioctl) {
- retval = ld->ioctl(tty, file, cmd, arg);
+ if (ld->ops->ioctl) {
+ retval = ld->ops->ioctl(tty, file, cmd, arg);
if (retval == -ENOIOCTLCMD)
retval = -EINVAL;
}
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;
}
ld = tty_ldisc_ref_wait(tty);
- if (ld->compat_ioctl)
- retval = ld->compat_ioctl(tty, file, cmd, arg);
+ if (ld->ops->compat_ioctl)
+ retval = ld->ops->compat_ioctl(tty, file, cmd, arg);
tty_ldisc_deref(ld);
return retval;
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 */
EXPORT_SYMBOL(do_SAK);
/**
- * flush_to_ldisc
- * @work: tty structure passed from work queue.
- *
- * This routine is called out of the software interrupt to flush data
- * from the buffer chain to the line discipline.
- *
- * Locking: holds tty->buf.lock to guard buffer list. Drops the lock
- * 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 =
- container_of(work, struct tty_struct, buf.work.work);
- unsigned long flags;
- struct tty_ldisc *disc;
- struct tty_buffer *tbuf, *head;
- char *char_buf;
- unsigned char *flag_buf;
-
- disc = tty_ldisc_ref(tty);
- if (disc == NULL) /* !TTY_LDISC */
- return;
-
- spin_lock_irqsave(&tty->buf.lock, flags);
- /* So we know a flush is running */
- set_bit(TTY_FLUSHING, &tty->flags);
- head = tty->buf.head;
- if (head != NULL) {
- tty->buf.head = NULL;
- for (;;) {
- int count = head->commit - head->read;
- if (!count) {
- if (head->next == NULL)
- break;
- tbuf = head;
- head = head->next;
- tty_buffer_free(tty, tbuf);
- continue;
- }
- /* Ldisc or user is trying to flush the buffers
- we are feeding to the ldisc, stop feeding the
- line discipline as we want to empty the queue */
- if (test_bit(TTY_FLUSHPENDING, &tty->flags))
- break;
- if (!tty->receive_room) {
- schedule_delayed_work(&tty->buf.work, 1);
- break;
- }
- if (count > tty->receive_room)
- count = tty->receive_room;
- char_buf = head->char_buf_ptr + head->read;
- flag_buf = head->flag_buf_ptr + head->read;
- head->read += count;
- spin_unlock_irqrestore(&tty->buf.lock, flags);
- disc->receive_buf(tty, char_buf, flag_buf, count);
- spin_lock_irqsave(&tty->buf.lock, flags);
- }
- /* Restore the queue head */
- tty->buf.head = head;
- }
- /* We may have a deferred request to flush the input buffer,
- if so pull the chain under the lock and empty the queue */
- if (test_bit(TTY_FLUSHPENDING, &tty->flags)) {
- __tty_buffer_flush(tty);
- clear_bit(TTY_FLUSHPENDING, &tty->flags);
- wake_up(&tty->read_wait);
- }
- clear_bit(TTY_FLUSHING, &tty->flags);
- spin_unlock_irqrestore(&tty->buf.lock, flags);
-
- tty_ldisc_deref(disc);
-}
-
-/**
- * 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.
- *
- * Locking: tty buffer lock. Driver locks in low latency mode.
- */
-
-void tty_flip_buffer_push(struct tty_struct *tty)
-{
- unsigned long flags;
- spin_lock_irqsave(&tty->buf.lock, flags);
- if (tty->buf.tail != NULL)
- tty->buf.tail->commit = tty->buf.tail->used;
- spin_unlock_irqrestore(&tty->buf.lock, flags);
-
- if (tty->low_latency)
- flush_to_ldisc(&tty->buf.work.work);
- else
- schedule_delayed_work(&tty->buf.work, 1);
-}
-
-EXPORT_SYMBOL(tty_flip_buffer_push);
-
-
-/**
* initialize_tty_struct
* @tty: tty to initialize
*
* Locking: none - tty in question must not be exposed at this point
*/
-static void initialize_tty_struct(struct tty_struct *tty)
+void initialize_tty_struct(struct tty_struct *tty,
+ struct tty_driver *driver, int idx)
{
memset(tty, 0, sizeof(struct tty_struct));
+ kref_init(&tty->kref);
tty->magic = TTY_MAGIC;
- tty_ldisc_assign(tty, tty_ldisc_get(N_TTY));
+ tty_ldisc_init(tty);
tty->session = NULL;
tty->pgrp = NULL;
tty->overrun_time = jiffies;
tty->buf.head = tty->buf.tail = NULL;
tty_buffer_init(tty);
- INIT_DELAYED_WORK(&tty->buf.work, flush_to_ldisc);
mutex_init(&tty->termios_mutex);
init_waitqueue_head(&tty->write_wait);
init_waitqueue_head(&tty->read_wait);
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);
+
+ tty->driver = driver;
+ tty->ops = driver->ops;
+ tty->index = idx;
+ tty_line_name(driver, idx, tty->name);
}
-/*
- * 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;
+struct class *tty_class;
/**
* tty_register_device - register a tty device
else
tty_line_name(driver, index, name);
- return device_create(tty_class, device, dev, name);
+ return device_create_drvdata(tty_class, device, dev, NULL, name);
}
+EXPORT_SYMBOL(tty_register_device);
/**
* tty_unregister_device - unregister a tty device
device_destroy(tty_class,
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)
driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL);
if (driver) {
+ kref_init(&driver->kref);
driver->magic = TTY_DRIVER_MAGIC;
driver->num = lines;
/* later we'll move allocation of tables here */
}
return driver;
}
+EXPORT_SYMBOL(alloc_tty_driver);
-void put_tty_driver(struct tty_driver *driver)
+static void destruct_tty_driver(struct kref *kref)
{
+ struct tty_driver *driver = container_of(kref, struct tty_driver, kref);
+ int i;
+ struct ktermios *tp;
+ void *p;
+
+ if (driver->flags & TTY_DRIVER_INSTALLED) {
+ /*
+ * 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_DYNAMIC_DEV))
+ 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);
+ }
kfree(driver);
}
-void tty_set_operations(struct tty_driver *driver,
- const struct tty_operations *op)
+void tty_driver_kref_put(struct tty_driver *driver)
{
- 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;
-#ifdef CONFIG_CONSOLE_POLL
- driver->poll_init = op->poll_init;
- driver->poll_get_char = op->poll_get_char;
- driver->poll_put_char = op->poll_put_char;
-#endif
+ kref_put(&driver->kref, destruct_tty_driver);
}
+EXPORT_SYMBOL(tty_driver_kref_put);
+void tty_set_operations(struct tty_driver *driver,
+ const struct tty_operations *op)
+{
+ driver->ops = op;
+};
+EXPORT_SYMBOL(tty_set_operations);
-EXPORT_SYMBOL(alloc_tty_driver);
+void put_tty_driver(struct tty_driver *d)
+{
+ tty_driver_kref_put(d);
+}
EXPORT_SYMBOL(put_tty_driver);
-EXPORT_SYMBOL(tty_set_operations);
/*
* Called by a tty driver to register itself.
dev_t dev;
void **p = NULL;
- if (driver->flags & TTY_DRIVER_INSTALLED)
- return 0;
-
if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) {
p = kzalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL);
if (!p)
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);
tty_register_device(driver, i, NULL);
}
proc_tty_register_driver(driver);
+ driver->flags |= TTY_DRIVER_INSTALLED;
return 0;
}
*/
int tty_unregister_driver(struct tty_driver *driver)
{
- int i;
- struct ktermios *tp;
- void *p;
-
+#if 0
+ /* FIXME */
if (driver->refcount)
return -EBUSY;
-
+#endif
unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
driver->num);
mutex_lock(&tty_mutex);
list_del(&driver->tty_drivers);
mutex_unlock(&tty_mutex);
-
- /*
- * 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_DYNAMIC_DEV))
- 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);
dev_t tty_devnum(struct tty_struct *tty)
void proc_clear_tty(struct task_struct *p)
{
+ struct tty_struct *tty;
spin_lock_irq(&p->sighand->siglock);
+ tty = p->signal->tty;
p->signal->tty = NULL;
spin_unlock_irq(&p->sighand->siglock);
+ tty_kref_put(tty);
}
-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));
+ if (tsk->signal->tty) {
+ printk(KERN_DEBUG "tty not NULL!!\n");
+ tty_kref_put(tsk->signal->tty);
+ }
}
put_pid(tsk->signal->tty_old_pgrp);
- tsk->signal->tty = tty;
+ tsk->signal->tty = tty_kref_get(tty);
tsk->signal->tty_old_pgrp = NULL;
}
struct tty_struct *get_current_tty(void)
{
struct tty_struct *tty;
- WARN_ON_ONCE(!mutex_is_locked(&tty_mutex));
- tty = current->signal->tty;
- /*
- * session->tty can be changed/cleared from under us, make sure we
- * issue the load. The obtained pointer, when not NULL, is valid as
- * long as we hold tty_mutex.
- */
- barrier();
+ unsigned long flags;
+
+ spin_lock_irqsave(¤t->sighand->siglock, flags);
+ tty = tty_kref_get(current->signal->tty);
+ spin_unlock_irqrestore(¤t->sighand->siglock, flags);
return tty;
}
EXPORT_SYMBOL_GPL(get_current_tty);
+void tty_default_fops(struct file_operations *fops)
+{
+ *fops = tty_fops;
+}
+
/*
* Initialize the console device. This is called *early*, so
* we can't necessarily depend on lots of kernel help here.
initcall_t *call;
/* Setup the default TTY line discipline. */
- (void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY);
+ tty_ldisc_begin();
/*
* set up the console device so that later boot sequences can
/* 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
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");
- device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), "tty");
+ device_create(tty_class, NULL, 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");
- device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), "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");
- device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), "ptmx");
-#endif
+ device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL,
+ "console");
#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");
- device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), "tty0");
-
- vty_init();
+ vty_init(&console_fops);
#endif
return 0;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff