diff options
Diffstat (limited to 'drivers/char/tty_io.c')
| -rw-r--r-- | drivers/char/tty_io.c | 1394 |
1 files changed, 415 insertions, 979 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index daeb8f76697..7053d633369 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 <Marko.Kohtala@hut.fi>, March 97 * - * Rewrote init_dev and release_dev to eliminate races. + * Rewrote tty_init_dev and tty_release_dev to eliminate races. * -- Bill Hawes <whawes@star.net>, June 97 * * Added devfs support. @@ -136,13 +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 */ -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 *, @@ -171,13 +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 @@ -187,7 +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); @@ -263,398 +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); - - - /** * get_tty_driver - find device of a tty * @dev_t: device identifier @@ -675,7 +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; } @@ -695,13 +294,23 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line) { struct tty_driver *p, *res = NULL; int tty_line = 0; + int len; char *str; + for (str = name; *str; str++) + if ((*str >= '0' && *str <= '9') || *str == ',') + break; + if (!*str) + return NULL; + + len = str - name; + tty_line = simple_strtoul(str, &str, 10); + mutex_lock(&tty_mutex); /* Search through the tty devices to look for a match */ list_for_each_entry(p, &tty_drivers, tty_drivers) { - str = name + strlen(p->name); - tty_line = simple_strtoul(str, &str, 10); + if (strncmp(name, p->name, len) != 0) + continue; if (*str == ',') str++; if (*str == '\0') @@ -709,7 +318,7 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line) if (tty_line >= 0 && tty_line <= p->num && p->ops && p->ops->poll_init && !p->ops->poll_init(p, tty_line, str)) { - res = p; + res = tty_driver_kref_get(p); *line = tty_line; break; } @@ -809,20 +418,6 @@ static const struct file_operations tty_fops = { .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, - .unlocked_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, @@ -943,6 +538,7 @@ static void do_tty_hangup(struct work_struct *work) struct tty_ldisc *ld; int closecount = 0, n; unsigned long flags; + int refs = 0; if (!tty) return; @@ -1009,8 +605,12 @@ static void do_tty_hangup(struct work_struct *work) 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; @@ -1036,6 +636,10 @@ static void do_tty_hangup(struct work_struct *work) tty->ctrl_status = 0; spin_unlock_irqrestore(&tty->ctrl_lock, flags); + /* Account for the p->signal references we killed */ + while (refs--) + tty_kref_put(tty); + /* * If one of the devices matches a console pointer, we * cannot just call hangup() because that will cause @@ -1105,6 +709,23 @@ 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 * @@ -1157,16 +778,14 @@ void disassociate_ctty(int on_exit) struct pid *tty_pgrp = NULL; - mutex_lock(&tty_mutex); tty = get_current_tty(); if (tty) { tty_pgrp = get_pid(tty->pgrp); lock_kernel(); - mutex_unlock(&tty_mutex); - /* XXX: here we race, there is nothing protecting tty */ 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); @@ -1178,7 +797,6 @@ void disassociate_ctty(int on_exit) kill_pgrp(old_pgrp, SIGCONT, on_exit); put_pid(old_pgrp); } - mutex_unlock(&tty_mutex); return; } if (tty_pgrp) { @@ -1193,8 +811,6 @@ 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; @@ -1204,13 +820,13 @@ void disassociate_ctty(int on_exit) 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); @@ -1410,19 +1026,19 @@ 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 .. */ @@ -1456,6 +1072,31 @@ out: return ret; } +/** + * tty_write_message - write a message to a certain tty, not just the console. + * @tty: the destination tty_struct + * @msg: the message to write + * + * This is used for messages that need to be redirected to a specific tty. + * We don't put it into the syslog queue right now maybe in the future if + * really needed. + * + * We must still hold the BKL and test the CLOSING flag for the moment. + */ + +void tty_write_message(struct tty_struct *tty, char *msg) +{ + lock_kernel(); + if (tty) { + mutex_lock(&tty->atomic_write_lock); + if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) + tty->ops->write(tty, msg, strlen(msg)); + tty_write_unlock(tty); + } + unlock_kernel(); + return; +} + /** * tty_write - write method for tty device file @@ -1523,42 +1164,6 @@ ssize_t redirected_tty_write(struct file *file, const char __user *buf, return tty_write(file, buf, count, ppos); } -void tty_port_init(struct tty_port *port) -{ - memset(port, 0, sizeof(*port)); - init_waitqueue_head(&port->open_wait); - init_waitqueue_head(&port->close_wait); - mutex_init(&port->mutex); - port->close_delay = (50 * HZ) / 100; - port->closing_wait = (3000 * HZ) / 100; -} -EXPORT_SYMBOL(tty_port_init); - -int tty_port_alloc_xmit_buf(struct tty_port *port) -{ - /* We may sleep in get_zeroed_page() */ - mutex_lock(&port->mutex); - if (port->xmit_buf == NULL) - port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); - mutex_unlock(&port->mutex); - if (port->xmit_buf == NULL) - return -ENOMEM; - return 0; -} -EXPORT_SYMBOL(tty_port_alloc_xmit_buf); - -void tty_port_free_xmit_buf(struct tty_port *port) -{ - mutex_lock(&port->mutex); - if (port->xmit_buf != NULL) { - free_page((unsigned long)port->xmit_buf); - port->xmit_buf = NULL; - } - mutex_unlock(&port->mutex); -} -EXPORT_SYMBOL(tty_port_free_xmit_buf); - - static char ptychar[] = "pqrstuvwxyzabcde"; /** @@ -1582,7 +1187,7 @@ 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 @@ -1598,10 +1203,148 @@ 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 + */ +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?? */ + + WARN_ON(!test_bit(TTY_LDISC, &tty->flags)); + + return 0; +} + +/** + * tty_init_dev - initialise a tty device * @driver: tty driver we are opening a device on * @idx: device index - * @tty: returned tty structure + * @ret_tty: returned tty structure + * @first_ok: ok to open a new device (used by ptmx) * * Prepare a tty device. This may not be a "new" clean device but * could also be an active device. The pty drivers require special @@ -1621,37 +1364,16 @@ 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. @@ -1661,189 +1383,69 @@ 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->ops = driver->ops; - 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]; - } + initialize_tty_struct(tty, driver, idx); - if (!*tp_loc) { - tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL); - if (!tp) - goto free_mem_out; - *tp = driver->init_termios; - } - - if (!*ltp_loc) { - ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL); - if (!ltp) - goto free_mem_out; - } - - if (driver->type == TTY_DRIVER_TYPE_PTY) { - o_tty = alloc_tty_struct(); - if (!o_tty) - goto free_mem_out; - initialize_tty_struct(o_tty); - o_tty->driver = driver->other; - o_tty->ops = driver->ops; - 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. */ - retval = tty_ldisc_setup(tty, o_tty); - + retval = tty_ldisc_setup(tty, tty->link); if (retval) goto release_mem_out; - 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); + 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 @@ -1853,31 +1455,19 @@ 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); @@ -1887,6 +1477,21 @@ 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), @@ -1897,15 +1502,16 @@ 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); } /* @@ -1916,20 +1522,21 @@ 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]; + 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); @@ -1941,33 +1548,27 @@ 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 @@ -1975,26 +1576,19 @@ 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; } } @@ -2052,7 +1646,7 @@ static void release_dev(struct file *filp) 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(); @@ -2065,14 +1659,14 @@ 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; } @@ -2135,11 +1729,11 @@ static void release_dev(struct file *filp) /* Make this pty number available for reallocation */ if (devpts) - devpts_kill_index(idx); + 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 * @@ -2154,14 +1748,14 @@ 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) { - struct tty_struct *tty; + struct tty_struct *tty = NULL; int noctty, retval; struct tty_driver *driver; int index; @@ -2183,23 +1777,25 @@ 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); + driver = tty_driver_kref_get(console_device(&index)); if (driver) { /* Don't let /dev/console block */ filp->f_flags |= O_NONBLOCK; @@ -2216,10 +1812,25 @@ 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)) + 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); @@ -2247,7 +1858,7 @@ 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)) @@ -2286,69 +1897,6 @@ static int tty_open(struct inode *inode, struct file *filp) -#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; - - nonseekable_open(inode, filp); - - /* find a device that is not in use. */ - index = devpts_new_index(); - if (index < 0) - return index; - - mutex_lock(&tty_mutex); - retval = init_dev(ptm_driver, index, &tty); - mutex_unlock(&tty_mutex); - - if (retval) - goto out; - - set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ - filp->private_data = tty; - file_move(filp, &tty->tty_files); - - retval = devpts_pty_new(tty->link); - if (retval) - goto out1; - - check_tty_count(tty, "ptmx_open"); - retval = ptm_driver->ops->open(tty, filp); - if (!retval) - return 0; -out1: - release_dev(filp); - return retval; -out: - devpts_kill_index(index); - return retval; -} - -static int ptmx_open(struct inode *inode, struct file *filp) -{ - int ret; - - lock_kernel(); - ret = __ptmx_open(inode, filp); - unlock_kernel(); - return ret; -} -#endif /** * tty_release - vfs callback for close @@ -2359,13 +1907,13 @@ static int ptmx_open(struct inode *inode, struct file *filp) * 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; } @@ -2514,7 +2062,7 @@ int tty_do_resize(struct tty_struct *tty, struct tty_struct *real_tty, /* For a PTY we need to lock the tty side */ mutex_lock(&real_tty->termios_mutex); - if (!memcmp(ws, &tty->winsize, sizeof(*ws))) + if (!memcmp(ws, &real_tty->winsize, sizeof(*ws))) goto done; /* Get the PID values and reference them so we can avoid holding the tty ctrl lock while sending signals */ @@ -2986,7 +2534,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case TIOCSTI: return tiocsti(tty, p); case TIOCGWINSZ: - return tiocgwinsz(tty, p); + return tiocgwinsz(real_tty, p); case TIOCSWINSZ: return tiocswinsz(tty, real_tty, p); case TIOCCONS: @@ -3016,10 +2564,6 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 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 */ @@ -3210,113 +2754,6 @@ 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->ops->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 * @@ -3326,9 +2763,11 @@ 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_init(tty); tty->session = NULL; @@ -3336,7 +2775,6 @@ static void initialize_tty_struct(struct tty_struct *tty) tty->overrun_time = jiffies; tty->buf.head = tty->buf.tail = NULL; tty_buffer_init(tty); - INIT_DELAYED_WORK(&tty->buf.work, flush_to_ldisc); mutex_init(&tty->termios_mutex); init_waitqueue_head(&tty->write_wait); init_waitqueue_head(&tty->read_wait); @@ -3347,6 +2785,11 @@ static void initialize_tty_struct(struct tty_struct *tty) 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); } /** @@ -3367,10 +2810,9 @@ int tty_put_char(struct tty_struct *tty, unsigned char ch) 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 @@ -3410,6 +2852,7 @@ struct device *tty_register_device(struct tty_driver *driver, unsigned index, return device_create_drvdata(tty_class, device, dev, NULL, name); } +EXPORT_SYMBOL(tty_register_device); /** * tty_unregister_device - unregister a tty device @@ -3427,8 +2870,6 @@ 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) @@ -3437,27 +2878,65 @@ 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_driver_kref_put(struct tty_driver *driver) +{ + 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. @@ -3469,11 +2948,8 @@ 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; } @@ -3497,12 +2973,9 @@ 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); @@ -3511,7 +2984,7 @@ 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; } @@ -3525,6 +2998,7 @@ 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; } @@ -3535,46 +3009,19 @@ 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) @@ -3585,9 +3032,12 @@ EXPORT_SYMBOL(tty_devnum); void proc_clear_tty(struct task_struct *p) { + struct tty_struct *tty; spin_lock_irq(&p->sighand->siglock); + tty = p->signal->tty; p->signal->tty = NULL; spin_unlock_irq(&p->sighand->siglock); + tty_kref_put(tty); } /* Called under the sighand lock */ @@ -3603,9 +3053,13 @@ static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) 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; } @@ -3619,18 +3073,20 @@ 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. @@ -3668,12 +3124,6 @@ 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 @@ -3685,32 +3135,18 @@ 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_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, + 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_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, + device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, "console"); -#ifdef CONFIG_UNIX98_PTYS - cdev_init(&ptmx_cdev, &ptmx_fops); - if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || - register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) - panic("Couldn't register /dev/ptmx driver\n"); - device_create_drvdata(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); -#endif - #ifdef CONFIG_VT - cdev_init(&vc0_cdev, &console_fops); - if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) || - register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0) - panic("Couldn't register /dev/tty0 driver\n"); - device_create_drvdata(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0"); - - vty_init(); + vty_init(&console_fops); #endif return 0; } |