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Diffstat (limited to 'drivers/char/tty_io.c')
-rw-r--r--drivers/char/tty_io.c1387
1 files changed, 407 insertions, 980 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index e4dce8709541..59f472143f08 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;
}
@@ -719,7 +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;
}
@@ -819,20 +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,
@@ -953,6 +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;
@@ -1019,8 +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;
@@ -1046,6 +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
@@ -1115,6 +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
*
@@ -1167,16 +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(&current->sighand->siglock);
@@ -1188,7 +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) {
@@ -1203,8 +811,6 @@ void disassociate_ctty(int on_exit)
current->signal->tty_old_pgrp = NULL;
spin_unlock_irq(&current->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;
@@ -1214,13 +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);
@@ -1420,19 +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 .. */
@@ -1466,6 +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
@@ -1533,42 +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";
/**
@@ -1592,7 +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
@@ -1608,10 +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
@@ -1631,37 +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.
@@ -1671,189 +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];
- }
-
- 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];
- }
+ initialize_tty_struct(tty, driver, idx);
- if (!*o_tp_loc) {
- o_tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
- if (!o_tp)
- goto free_mem_out;
- *o_tp = driver->other->init_termios;
- }
-
- if (!*o_ltp_loc) {
- o_ltp = kzalloc(sizeof(struct ktermios), GFP_KERNEL);
- if (!o_ltp)
- goto free_mem_out;
- }
-
- /*
- * Everything allocated ... set up the o_tty structure.
- */
- if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM))
- driver->other->ttys[idx] = o_tty;
- if (!*o_tp_loc)
- *o_tp_loc = o_tp;
- if (!*o_ltp_loc)
- *o_ltp_loc = o_ltp;
- o_tty->termios = *o_tp_loc;
- o_tty->termios_locked = *o_ltp_loc;
- driver->other->refcount++;
- if (driver->subtype == PTY_TYPE_MASTER)
- o_tty->count++;
-
- /* Establish the links in both directions */
- tty->link = o_tty;
- o_tty->link = tty;
+ retval = tty_driver_install_tty(driver, tty);
+ if (retval < 0) {
+ free_tty_struct(tty);
+ module_put(driver->owner);
+ return ERR_PTR(retval);
}
/*
- * All structures have been allocated, so now we install them.
- * Failures after this point use release_tty to clean up, so
- * there's no need to null out the local pointers.
- */
- if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM))
- driver->ttys[idx] = tty;
-
- if (!*tp_loc)
- *tp_loc = tp;
- if (!*ltp_loc)
- *ltp_loc = ltp;
- tty->termios = *tp_loc;
- tty->termios_locked = *ltp_loc;
- /* Compatibility until drivers always set this */
- tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios);
- tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios);
- driver->refcount++;
- tty->count++;
-
- /*
* Structures all installed ... call the ldisc open routines.
* If we fail here just call release_tty to clean up. No need
* to decrement the use counts, as release_tty doesn't care.
*/
- 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
@@ -1863,31 +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);
@@ -1897,6 +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),
@@ -1907,15 +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);
}
/*
@@ -1926,20 +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);
@@ -1951,33 +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
@@ -1985,26 +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;
}
}
@@ -2062,7 +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();
@@ -2075,14 +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;
}
@@ -2145,11 +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
*
@@ -2164,14 +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;
@@ -2193,23 +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;
@@ -2226,10 +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);
@@ -2257,7 +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))
@@ -2296,69 +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
@@ -2369,13 +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;
}
@@ -2524,7 +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 */
@@ -2996,7 +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:
@@ -3026,10 +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
*/
@@ -3220,113 +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
*
@@ -3336,9 +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;
@@ -3346,7 +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);
@@ -3357,6 +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);
}
/**
@@ -3377,10 +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
@@ -3418,8 +2850,9 @@ struct device *tty_register_device(struct tty_driver *driver, unsigned index,
else
tty_line_name(driver, index, name);
- return device_create_drvdata(tty_class, device, dev, NULL, name);
+ return device_create(tty_class, device, dev, NULL, name);
}
+EXPORT_SYMBOL(tty_register_device);
/**
* tty_unregister_device - unregister a tty device
@@ -3437,8 +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)
@@ -3447,27 +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.
@@ -3479,11 +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;
}
@@ -3507,12 +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);
@@ -3521,7 +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;
}
@@ -3535,6 +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;
}
@@ -3545,46 +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)
@@ -3595,9 +3032,13 @@ 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);
}
/* Called under the sighand lock */
@@ -3613,9 +3054,13 @@ 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;
}
@@ -3629,18 +3074,20 @@ 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(&current->sighand->siglock, flags);
+ tty = tty_kref_get(current->signal->tty);
+ spin_unlock_irqrestore(&current->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.
@@ -3678,12 +3125,6 @@ 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
@@ -3695,32 +3136,18 @@ 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;
}