X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=drivers%2Fchar%2Ftty_io.c;h=93844806773831a936615968832097a0bafa55be;hb=6146b9af84cc771198195104b432eb13b96a9799;hp=4d3c7018f0c3a9198093ace1ed28b69747a2209b;hpb=f2d937f3bf00665ccf048b3b6616ef95859b0945;p=safe%2Fjmp%2Flinux-2.6 diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index 4d3c701..9384480 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -49,7 +49,7 @@ * implement CONFIG_VT and generalize console device interface. * -- Marko Kohtala , March 97 * - * Rewrote init_dev and release_dev to eliminate races. + * Rewrote tty_init_dev and tty_release_dev to eliminate races. * -- Bill Hawes , June 97 * * Added devfs support. @@ -78,6 +78,7 @@ #include #include #include +#include #include #include #include @@ -91,12 +92,12 @@ #include #include #include -#include #include #include #include +#include -#include +#include #include #include @@ -135,16 +136,6 @@ LIST_HEAD(tty_drivers); /* linked list of tty drivers */ 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 *, @@ -152,8 +143,7 @@ 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); @@ -174,13 +164,11 @@ static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); * 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 @@ -190,7 +178,7 @@ static void tty_buffer_free_all(struct tty_struct *); * 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); @@ -266,870 +254,6 @@ static int check_tty_count(struct tty_struct *tty, const char *routine) 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 */ - /* Cyrus Durgin */ - 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 @@ -1150,7 +274,7 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index) if (device < base || device >= base + p->num) continue; *index = device - base; - return p; + return tty_driver_kref_get(p); } return NULL; } @@ -1170,22 +294,32 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line) { struct tty_driver *p, *res = NULL; int tty_line = 0; - char *str; + int len; + char *str, *stp; + + 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 (*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)) { - - res = p; + if (strncmp(name, p->name, len) != 0) + continue; + stp = str; + if (*stp == ',') + stp++; + if (*stp == '\0') + stp = NULL; + + if (tty_line >= 0 && tty_line <= p->num && p->ops && + p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { + res = tty_driver_kref_get(p); *line = tty_line; break; } @@ -1205,26 +339,40 @@ EXPORT_SYMBOL_GPL(tty_find_polling_driver); * 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); @@ -1247,8 +395,8 @@ 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; } @@ -1264,33 +412,19 @@ 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, .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, @@ -1302,7 +436,7 @@ 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, }; @@ -1326,54 +460,17 @@ void tty_wakeup(struct tty_struct *tty) 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); } } - wake_up_interruptible(&tty->write_wait); + wake_up_interruptible_poll(&tty->write_wait, POLLOUT); } EXPORT_SYMBOL_GPL(tty_wakeup); /** - * tty_ldisc_flush - flush line discipline queue - * @tty: tty - * - * Flush the line discipline queue (if any) for this tty. If there - * is no line discipline active this is a no-op. - */ - -void tty_ldisc_flush(struct tty_struct *tty) -{ - struct tty_ldisc *ld = tty_ldisc_ref(tty); - if (ld) { - if (ld->flush_buffer) - ld->flush_buffer(tty); - tty_ldisc_deref(ld); - } - tty_buffer_flush(tty); -} - -EXPORT_SYMBOL_GPL(tty_ldisc_flush); - -/** - * tty_reset_termios - reset terminal state - * @tty: tty to reset - * - * Restore a terminal to the driver default state - */ - -static void tty_reset_termios(struct tty_struct *tty) -{ - mutex_lock(&tty->termios_mutex); - *tty->termios = tty->driver->init_termios; - tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); - 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 * @@ -1402,8 +499,9 @@ static void do_tty_hangup(struct work_struct *work) 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; + int refs = 0; if (!tty) return; @@ -1431,48 +529,19 @@ 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. - */ - ld = tty_ldisc_ref(tty); - if (ld != NULL) { - /* We may have no line discipline at this point */ - if (ld->flush_buffer) - ld->flush_buffer(tty); - if (tty->driver->flush_buffer) - tty->driver->flush_buffer(tty); - if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) && - ld->write_wakeup) - ld->write_wakeup(tty); - if (ld->hangup) - ld->hangup(tty); - } - /* - * FIXME: Once we trust the LDISC code better we can wait here for - * ldisc completion and fix the driver call race - */ - wake_up_interruptible(&tty->write_wait); - wake_up_interruptible(&tty->read_wait); - /* - * Shutdown the current line discipline, and reset it to - * N_TTY. - */ - if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) - 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 */ + tty_ldisc_hangup(tty); read_lock(&tasklist_lock); 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; @@ -1480,19 +549,31 @@ 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); - tty->flags = 0; + spin_lock_irqsave(&tty->ctrl_lock, flags); + clear_bit(TTY_THROTTLED, &tty->flags); + clear_bit(TTY_PUSH, &tty->flags); + clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); put_pid(tty->session); put_pid(tty->pgrp); tty->session = NULL; tty->pgrp = NULL; tty->ctrl_status = 0; + set_bit(TTY_HUPPED, &tty->flags); + 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 @@ -1500,11 +581,11 @@ static void do_tty_hangup(struct work_struct *work) * 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 @@ -1512,10 +593,7 @@ static void do_tty_hangup(struct work_struct *work) * can't yet guarantee all that. */ set_bit(TTY_HUPPED, &tty->flags); - if (ld) { - tty_ldisc_enable(tty); - tty_ldisc_deref(ld); - } + tty_ldisc_enable(tty); unlock_kernel(); if (f) fput(f); @@ -1562,6 +640,23 @@ void tty_vhangup(struct tty_struct *tty) EXPORT_SYMBOL(tty_vhangup); /** + * tty_vhangup_self - process vhangup for own ctty + * + * Perform a vhangup on the current controlling tty + */ + +void tty_vhangup_self(void) +{ + struct tty_struct *tty; + + tty = get_current_tty(); + if (tty) { + tty_vhangup(tty); + tty_kref_put(tty); + } +} + +/** * tty_hung_up_p - was tty hung up * @filp: file pointer of tty * @@ -1576,19 +671,6 @@ int tty_hung_up_p(struct file *filp) EXPORT_SYMBOL(tty_hung_up_p); -/** - * 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 - || filp->f_op->read == hung_up_tty_read; -} - static void session_clear_tty(struct pid *session) { struct task_struct *p; @@ -1626,16 +708,15 @@ 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); - /* 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); @@ -1647,8 +728,6 @@ void disassociate_ctty(int on_exit) kill_pgrp(old_pgrp, SIGCONT, on_exit); put_pid(old_pgrp); } - mutex_unlock(&tty_mutex); - unlock_kernel(); return; } if (tty_pgrp) { @@ -1663,27 +742,27 @@ void disassociate_ctty(int on_exit) 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(); } /** @@ -1693,8 +772,10 @@ 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); } @@ -1714,21 +795,26 @@ 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); + wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); } - 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); @@ -1743,21 +829,26 @@ EXPORT_SYMBOL(stop_tty); * driver start method is invoked and the line discipline woken. * * Locking: - * Broken. Relies on BKL which is unsafe here. + * ctrl_lock */ void start_tty(struct tty_struct *tty) { - if (!tty->stopped || tty->flow_stopped) + unsigned long flags; + spin_lock_irqsave(&tty->ctrl_lock, flags); + if (!tty->stopped || tty->flow_stopped) { + spin_unlock_irqrestore(&tty->ctrl_lock, flags); return; + } tty->stopped = 0; if (tty->link && tty->link->packet) { tty->ctrl_status &= ~TIOCPKT_STOP; tty->ctrl_status |= TIOCPKT_START; - wake_up_interruptible(&tty->link->read_wait); + wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); } - 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); } @@ -1775,10 +866,8 @@ 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, @@ -1799,13 +888,11 @@ 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); + 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; @@ -1814,7 +901,7 @@ static ssize_t tty_read(struct file *file, char __user *buf, size_t count, void tty_write_unlock(struct tty_struct *tty) { mutex_unlock(&tty->atomic_write_lock); - wake_up_interruptible(&tty->write_wait); + wake_up_interruptible_poll(&tty->write_wait, POLLOUT); } int tty_write_lock(struct tty_struct *tty, int ndelay) @@ -1870,19 +957,19 @@ static inline ssize_t do_tty_write( /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ if (tty->write_cnt < chunk) { - unsigned char *buf; + unsigned char *buf_chunk; if (chunk < 1024) chunk = 1024; - buf = kmalloc(chunk, GFP_KERNEL); - if (!buf) { + buf_chunk = kmalloc(chunk, GFP_KERNEL); + if (!buf_chunk) { ret = -ENOMEM; goto out; } kfree(tty->write_buf); tty->write_cnt = chunk; - tty->write_buf = buf; + tty->write_buf = buf_chunk; } /* Do the write .. */ @@ -1893,9 +980,7 @@ 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; @@ -1913,9 +998,34 @@ static inline ssize_t do_tty_write( inode->i_mtime = current_fs_time(inode->i_sb); ret = written; } -out: - tty_write_unlock(tty); - return ret; +out: + tty_write_unlock(tty); + 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; } @@ -1932,9 +1042,7 @@ out: * Locks the line discipline as required * Writes to the tty driver are serialized by the atomic_write_lock * and are then processed in chunks to the device. The line discipline - * write method will not be involked in parallel for each device - * The line discipline write method is called under the big - * kernel lock for historical reasons. New code should not rely on this. + * write method will not be invoked in parallel for each device. */ static ssize_t tty_write(struct file *file, const char __user *buf, @@ -1948,15 +1056,18 @@ static ssize_t tty_write(struct file *file, const char __user *buf, 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; } @@ -2005,7 +1116,7 @@ static void pty_line_name(struct tty_driver *driver, int index, char *p) } /** - * 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 @@ -2021,10 +1132,150 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p) } /** - * 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 + */ +static 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; + int idx = tty->index; + + tp = tty->driver->termios[idx]; + if (tp == NULL) { + tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); + if (tp == NULL) + return -ENOMEM; + memcpy(tp, &tty->driver->init_termios, + sizeof(struct ktermios)); + tty->driver->termios[idx] = tp; + } + tty->termios = tp; + tty->termios_locked = tp + 1; + + /* Compatibility until drivers always set this */ + tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); + tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); + 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?? */ + + mutex_lock(&tty->ldisc_mutex); + WARN_ON(!test_bit(TTY_LDISC, &tty->flags)); + mutex_unlock(&tty->ldisc_mutex); + + 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 @@ -2044,37 +1295,16 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p) * 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. @@ -2084,198 +1314,69 @@ static int init_dev(struct tty_driver *driver, int idx, * 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; - } + initialize_tty_struct(tty, driver, idx); - if (driver->type == TTY_DRIVER_TYPE_PTY) { - o_tty = alloc_tty_struct(); - if (!o_tty) - goto free_mem_out; - initialize_tty_struct(o_tty); - o_tty->driver = driver->other; - o_tty->index = idx; - tty_line_name(driver->other, idx, o_tty->name); - - if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { - o_tp_loc = &o_tty->termios; - o_ltp_loc = &o_tty->termios_locked; - } else { - o_tp_loc = &driver->other->termios[idx]; - o_ltp_loc = &driver->other->termios_locked[idx]; - } - - if (!*o_tp_loc) { - o_tp = 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); + } +} +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 @@ -2285,31 +1386,19 @@ release_mem_out: * 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); @@ -2319,6 +1408,21 @@ static void release_one_tty(struct tty_struct *tty, int idx) } /** + * 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), @@ -2329,15 +1433,16 @@ static void release_one_tty(struct tty_struct *tty, int idx) * 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); } /* @@ -2348,21 +1453,21 @@ 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) +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); @@ -2374,33 +1479,27 @@ static void release_dev(struct file *filp) #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 " - "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 @@ -2408,32 +1507,25 @@ static void release_dev(struct file *filp) 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[" - "%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 @@ -2464,28 +1556,28 @@ static void release_dev(struct file *filp) if (tty_closing) { if (waitqueue_active(&tty->read_wait)) { - wake_up(&tty->read_wait); + wake_up_poll(&tty->read_wait, POLLIN); do_sleep++; } if (waitqueue_active(&tty->write_wait)) { - wake_up(&tty->write_wait); + wake_up_poll(&tty->write_wait, POLLOUT); do_sleep++; } } if (o_tty_closing) { if (waitqueue_active(&o_tty->read_wait)) { - wake_up(&o_tty->read_wait); + wake_up_poll(&o_tty->read_wait, POLLIN); do_sleep++; } if (waitqueue_active(&o_tty->write_wait)) { - wake_up(&o_tty->write_wait); + wake_up_poll(&o_tty->write_wait, POLLOUT); do_sleep++; } } 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(); @@ -2498,14 +1590,14 @@ static void release_dev(struct file *filp) */ 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; } @@ -2557,74 +1649,22 @@ static void release_dev(struct file *filp) 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 * @@ -2639,19 +1679,19 @@ static void release_dev(struct file *filp) * 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; dev_t device = inode->i_rdev; - unsigned short saved_flags = filp->f_flags; + unsigned saved_flags = filp->f_flags; nonseekable_open(inode, filp); @@ -2668,28 +1708,33 @@ retry_open: 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); - if (driver) { - /* Don't let /dev/console block */ - filp->f_flags |= O_NONBLOCK; - noctty = 1; - goto got_driver; + struct tty_driver *console_driver = console_device(&index); + if (console_driver) { + driver = tty_driver_kref_get(console_driver); + if (driver) { + /* Don't let /dev/console block */ + filp->f_flags |= O_NONBLOCK; + noctty = 1; + goto got_driver; + } } mutex_unlock(&tty_mutex); return -ENODEV; @@ -2701,10 +1746,27 @@ retry_open: 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)) { + mutex_unlock(&tty_mutex); + 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); @@ -2716,8 +1778,8 @@ 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; } @@ -2732,7 +1794,7 @@ got_driver: 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)) @@ -2751,87 +1813,26 @@ got_driver: if (!noctty && current->signal->leader && !current->signal->tty && - tty->session == NULL) - __proc_set_tty(current, tty); - spin_unlock_irq(¤t->sighand->siglock); - mutex_unlock(&tty_mutex); - tty_audit_opening(); - 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) -{ - 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); + tty->session == NULL) + __proc_set_tty(current, tty); + spin_unlock_irq(¤t->sighand->siglock); mutex_unlock(&tty_mutex); + return 0; +} - if (retval) - goto out; +/* BKL pushdown: scary code avoidance wrapper */ +static int tty_open(struct inode *inode, struct file *filp) +{ + int ret; + + 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) { - tty_audit_opening(); - 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 @@ -2842,13 +1843,13 @@ out: * 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; } @@ -2876,8 +1877,8 @@ static unsigned int tty_poll(struct file *filp, poll_table *wait) 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; } @@ -2885,21 +1886,24 @@ static unsigned int tty_poll(struct file *filp, poll_table *wait) 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; @@ -2907,14 +1911,18 @@ 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; + 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; } /** @@ -2943,8 +1951,9 @@ static int tiocsti(struct tty_struct *tty, char __user *p) return -EPERM; if (get_user(ch, p)) return -EFAULT; + tty_audit_tiocsti(tty, ch); 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; } @@ -2972,8 +1981,43 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) } /** + * tty_do_resize - resize event + * @tty: tty being resized + * @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 winsize *ws) +{ + struct pid *pgrp; + unsigned long flags; + + /* Lock the tty */ + mutex_lock(&tty->termios_mutex); + if (!memcmp(ws, &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); + spin_unlock_irqrestore(&tty->ctrl_lock, flags); + + if (pgrp) + kill_pgrp(pgrp, SIGWINCH, 1); + put_pid(pgrp); + + tty->winsize = *ws; +done: + mutex_unlock(&tty->termios_mutex); + return 0; +} + +/** * tiocswinsz - implement window size set ioctl - * @tty; tty + * @tty; tty side of tty * @arg: user buffer for result * * Copies the user idea of the window size to the kernel. Traditionally @@ -2981,43 +2025,21 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) * 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) +static int tiocswinsz(struct tty_struct *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, &tmp_ws); + else + return tty_do_resize(tty, &tmp_ws); } /** @@ -3063,7 +2085,7 @@ static int tioccons(struct file *file) * the generic functionality existed. This piece of history is preserved * in the expected tty API of posix OS's. * - * Locking: none, the open fle handle ensures it won't go away. + * Locking: none, the open file handle ensures it won't go away. */ static int fionbio(struct file *file, int __user *p) @@ -3073,10 +2095,12 @@ static int fionbio(struct file *file, int __user *p) if (get_user(nonblock, p)) return -EFAULT; + spin_lock(&file->f_lock); if (nonblock) file->f_flags |= O_NONBLOCK; else file->f_flags &= ~O_NONBLOCK; + spin_unlock(&file->f_lock); return 0; } @@ -3134,6 +2158,27 @@ 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 @@ -3147,13 +2192,18 @@ unlock: static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) { + struct pid *pid; + int ret; /* * (tty == real_tty) is a cheap way of * testing if the tty is NOT a master pty. */ if (tty == real_tty && current->signal->tty != real_tty) return -ENOTTY; - return put_user(pid_vnr(real_tty->pgrp), p); + pid = tty_get_pgrp(real_tty); + ret = put_user(pid_vnr(pid), p); + put_pid(pid); + return ret; } /** @@ -3165,7 +2215,7 @@ 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) @@ -3173,6 +2223,7 @@ 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; @@ -3195,8 +2246,10 @@ 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; @@ -3240,10 +2293,16 @@ 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; } /** @@ -3261,20 +2320,33 @@ static int tiocsetd(struct tty_struct *tty, int __user *p) 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 @@ -3289,8 +2361,8 @@ 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); @@ -3299,7 +2371,7 @@ 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 @@ -3314,82 +2386,67 @@ static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p 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; + int retval; + unsigned int set, clear, val; - retval = get_user(val, p); - if (retval) - return retval; + if (tty->ops->tiocmset == NULL) + return -EINVAL; - set = clear = 0; - switch (cmd) { - case TIOCMBIS: - set = val; - break; - case TIOCMBIC: - clear = val; - break; - case TIOCMSET: - set = val; - clear = ~val; - break; - } + retval = get_user(val, p); + if (retval) + return retval; + set = clear = 0; + switch (cmd) { + case TIOCMBIS: + set = val; + break; + case TIOCMBIC: + clear = val; + break; + case TIOCMSET: + set = val; + clear = ~val; + break; + } + set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; + clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; + return tty->ops->tiocmset(tty, file, set, clear); +} - set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; - clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; +struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) +{ + if (tty->driver->type == TTY_DRIVER_TYPE_PTY && + tty->driver->subtype == PTY_TYPE_MASTER) + tty = tty->link; + return tty; +} +EXPORT_SYMBOL(tty_pair_get_tty); - retval = tty->driver->tiocmset(tty, file, set, clear); - } - return retval; +struct tty_struct *tty_pair_get_pty(struct tty_struct *tty) +{ + if (tty->driver->type == TTY_DRIVER_TYPE_PTY && + tty->driver->subtype == PTY_TYPE_MASTER) + return tty; + return tty->link; } +EXPORT_SYMBOL(tty_pair_get_pty); /* * 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; - } - } + real_tty = tty_pair_get_tty(tty); /* * Factor out some common prep work @@ -3411,13 +2468,16 @@ int tty_ioctl(struct inode *inode, struct file *file, 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); + return tiocswinsz(real_tty, p); case TIOCCONS: return real_tty != tty ? -EINVAL : tioccons(file); case FIONBIO: @@ -3442,23 +2502,19 @@ int tty_ioctl(struct inode *inode, struct file *file, 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 @@ -3487,15 +2543,15 @@ int tty_ioctl(struct inode *inode, struct file *file, } 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; } @@ -3515,15 +2571,15 @@ 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; } 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; @@ -3566,14 +2622,13 @@ void __do_SAK(struct tty_struct *tty) 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", + " (%s): task_session(p)==tty->session\n", task_pid_nr(p), p->comm); send_sig(SIGKILL, p, 1); } while_each_pid_task(session, PIDTYPE_SID, p); @@ -3583,7 +2638,7 @@ void __do_SAK(struct tty_struct *tty) do_each_thread(g, p) { if (p->signal->tty == tty) { printk(KERN_NOTICE "SAK: killed process %d" - " (%s): task_session_nr(p)==tty->session\n", + " (%s): task_session(p)==tty->session\n", task_pid_nr(p), p->comm); send_sig(SIGKILL, p, 1); continue; @@ -3640,112 +2695,6 @@ void do_SAK(struct tty_struct *tty) 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 * @@ -3755,38 +2704,59 @@ EXPORT_SYMBOL(tty_flip_buffer_push); * 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); + mutex_init(&tty->ldisc_mutex); init_waitqueue_head(&tty->write_wait); init_waitqueue_head(&tty->read_wait); INIT_WORK(&tty->hangup_work, do_tty_hangup); mutex_init(&tty->atomic_read_lock); mutex_init(&tty->atomic_write_lock); + mutex_init(&tty->output_lock); + mutex_init(&tty->echo_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 @@ -3824,8 +2794,9 @@ struct device *tty_register_device(struct tty_driver *driver, unsigned index, else tty_line_name(driver, index, name); - return device_create(tty_class, device, dev, name); + return device_create(tty_class, device, dev, NULL, name); } +EXPORT_SYMBOL(tty_register_device); /** * tty_unregister_device - unregister a tty device @@ -3843,8 +2814,6 @@ void tty_unregister_device(struct tty_driver *driver, unsigned index) 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) @@ -3853,56 +2822,65 @@ 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); + } + if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) + tty_unregister_device(driver, i); + } + p = driver->ttys; + proc_tty_unregister_driver(driver); + driver->ttys = NULL; + driver->termios = NULL; + kfree(p); + cdev_del(&driver->cdev); + } 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. @@ -3914,11 +2892,8 @@ int tty_register_driver(struct tty_driver *driver) 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); + p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL); if (!p) return -ENOMEM; } @@ -3942,12 +2917,9 @@ 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); } else { driver->ttys = NULL; driver->termios = NULL; - driver->termios_locked = NULL; } cdev_init(&driver->cdev, &tty_fops); @@ -3956,14 +2928,11 @@ int tty_register_driver(struct tty_driver *driver) if (error) { unregister_chrdev_region(dev, driver->num); driver->ttys = NULL; - driver->termios = driver->termios_locked = NULL; + driver->termios = NULL; kfree(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); @@ -3973,6 +2942,7 @@ int tty_register_driver(struct tty_driver *driver) tty_register_device(driver, i, NULL); } proc_tty_register_driver(driver); + driver->flags |= TTY_DRIVER_INSTALLED; return 0; } @@ -3983,46 +2953,19 @@ EXPORT_SYMBOL(tty_register_driver); */ 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) @@ -4033,23 +2976,35 @@ EXPORT_SYMBOL(tty_devnum); void proc_clear_tty(struct task_struct *p) { - spin_lock_irq(&p->sighand->siglock); + unsigned long flags; + struct tty_struct *tty; + spin_lock_irqsave(&p->sighand->siglock, flags); + tty = p->signal->tty; p->signal->tty = NULL; - spin_unlock_irq(&p->sighand->siglock); + spin_unlock_irqrestore(&p->sighand->siglock, flags); + 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; } @@ -4063,18 +3018,20 @@ static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) 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. @@ -4086,7 +3043,7 @@ void __init console_init(void) 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 @@ -4112,12 +3069,6 @@ postcore_initcall(tty_class_init); /* 3/2004 jmc: why do these devices exist? */ static struct cdev tty_cdev, console_cdev; -#ifdef CONFIG_UNIX98_PTYS -static struct cdev ptmx_cdev; -#endif -#ifdef CONFIG_VT -static struct cdev vc0_cdev; -#endif /* * Ok, now we can initialize the rest of the tty devices and can count @@ -4129,30 +3080,18 @@ static int __init tty_init(void) 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; }