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path: root/drivers/char/tty_ioctl.c
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Diffstat (limited to 'drivers/char/tty_ioctl.c')
-rw-r--r--drivers/char/tty_ioctl.c212
1 files changed, 152 insertions, 60 deletions
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index bf34e4597421..a408c8e487ec 100644
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -40,6 +40,15 @@
#define TERMIOS_OLD 8
+/**
+ * tty_chars_in_buffer - characters pending
+ * @tty: terminal
+ *
+ * Return the number of bytes of data in the device private
+ * output queue. If no private method is supplied there is assumed
+ * to be no queue on the device.
+ */
+
int tty_chars_in_buffer(struct tty_struct *tty)
{
if (tty->ops->chars_in_buffer)
@@ -47,26 +56,49 @@ int tty_chars_in_buffer(struct tty_struct *tty)
else
return 0;
}
-
EXPORT_SYMBOL(tty_chars_in_buffer);
+/**
+ * tty_write_room - write queue space
+ * @tty: terminal
+ *
+ * Return the number of bytes that can be queued to this device
+ * at the present time. The result should be treated as a guarantee
+ * and the driver cannot offer a value it later shrinks by more than
+ * the number of bytes written. If no method is provided 2K is always
+ * returned and data may be lost as there will be no flow control.
+ */
+
int tty_write_room(struct tty_struct *tty)
{
if (tty->ops->write_room)
return tty->ops->write_room(tty);
return 2048;
}
-
EXPORT_SYMBOL(tty_write_room);
+/**
+ * tty_driver_flush_buffer - discard internal buffer
+ * @tty: terminal
+ *
+ * Discard the internal output buffer for this device. If no method
+ * is provided then either the buffer cannot be hardware flushed or
+ * there is no buffer driver side.
+ */
void tty_driver_flush_buffer(struct tty_struct *tty)
{
if (tty->ops->flush_buffer)
tty->ops->flush_buffer(tty);
}
-
EXPORT_SYMBOL(tty_driver_flush_buffer);
+/**
+ * tty_throttle - flow control
+ * @tty: terminal
+ *
+ * Indicate that a tty should stop transmitting data down the stack.
+ */
+
void tty_throttle(struct tty_struct *tty)
{
/* check TTY_THROTTLED first so it indicates our state */
@@ -76,6 +108,13 @@ void tty_throttle(struct tty_struct *tty)
}
EXPORT_SYMBOL(tty_throttle);
+/**
+ * tty_unthrottle - flow control
+ * @tty: terminal
+ *
+ * Indicate that a tty may continue transmitting data down the stack.
+ */
+
void tty_unthrottle(struct tty_struct *tty)
{
if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
@@ -112,6 +151,11 @@ void tty_wait_until_sent(struct tty_struct *tty, long timeout)
}
EXPORT_SYMBOL(tty_wait_until_sent);
+
+/*
+ * Termios Helper Methods
+ */
+
static void unset_locked_termios(struct ktermios *termios,
struct ktermios *old,
struct ktermios *locked)
@@ -346,6 +390,16 @@ void tty_termios_encode_baud_rate(struct ktermios *termios,
}
EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
+/**
+ * tty_encode_baud_rate - set baud rate of the tty
+ * @ibaud: input baud rate
+ * @obad: output baud rate
+ *
+ * Update the current termios data for the tty with the new speed
+ * settings. The caller must hold the termios_mutex for the tty in
+ * question.
+ */
+
void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
{
tty_termios_encode_baud_rate(tty->termios, ibaud, obaud);
@@ -430,12 +484,11 @@ EXPORT_SYMBOL(tty_termios_hw_change);
* is a bit of layering violation here with n_tty in terms of the
* internal knowledge of this function.
*
- * Locking: termios_sem
+ * Locking: termios_mutex
*/
static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
{
- int canon_change;
struct ktermios old_termios;
struct tty_ldisc *ld;
unsigned long flags;
@@ -451,18 +504,6 @@ static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
old_termios = *tty->termios;
*tty->termios = *new_termios;
unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
- canon_change = (old_termios.c_lflag ^ tty->termios->c_lflag) & ICANON;
- if (canon_change) {
- memset(&tty->read_flags, 0, sizeof tty->read_flags);
- tty->canon_head = tty->read_tail;
- tty->canon_data = 0;
- tty->erasing = 0;
- }
-
- /* This bit should be in the ldisc code */
- if (canon_change && !L_ICANON(tty) && tty->read_cnt)
- /* Get characters left over from canonical mode. */
- wake_up_interruptible(&tty->read_wait);
/* See if packet mode change of state. */
if (tty->link && tty->link->packet) {
@@ -508,7 +549,7 @@ static void change_termios(struct tty_struct *tty, struct ktermios *new_termios)
* functions before using change_termios to do the actual changes.
*
* Locking:
- * Called functions take ldisc and termios_sem locks
+ * Called functions take ldisc and termios_mutex locks
*/
static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
@@ -579,25 +620,51 @@ static int get_termio(struct tty_struct *tty, struct termio __user *termio)
return 0;
}
-static unsigned long inq_canon(struct tty_struct *tty)
+
+#ifdef TCGETX
+
+/**
+ * set_termiox - set termiox fields if possible
+ * @tty: terminal
+ * @arg: termiox structure from user
+ * @opt: option flags for ioctl type
+ *
+ * Implement the device calling points for the SYS5 termiox ioctl
+ * interface in Linux
+ */
+
+static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)
{
- int nr, head, tail;
+ struct termiox tnew;
+ struct tty_ldisc *ld;
- if (!tty->canon_data || !tty->read_buf)
- return 0;
- head = tty->canon_head;
- tail = tty->read_tail;
- nr = (head - tail) & (N_TTY_BUF_SIZE-1);
- /* Skip EOF-chars.. */
- while (head != tail) {
- if (test_bit(tail, tty->read_flags) &&
- tty->read_buf[tail] == __DISABLED_CHAR)
- nr--;
- tail = (tail+1) & (N_TTY_BUF_SIZE-1);
+ if (tty->termiox == NULL)
+ return -EINVAL;
+ if (copy_from_user(&tnew, arg, sizeof(struct termiox)))
+ return -EFAULT;
+
+ ld = tty_ldisc_ref(tty);
+ if (ld != NULL) {
+ if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
+ ld->ops->flush_buffer(tty);
+ tty_ldisc_deref(ld);
}
- return nr;
+ if (opt & TERMIOS_WAIT) {
+ tty_wait_until_sent(tty, 0);
+ if (signal_pending(current))
+ return -EINTR;
+ }
+
+ mutex_lock(&tty->termios_mutex);
+ if (tty->ops->set_termiox)
+ tty->ops->set_termiox(tty, &tnew);
+ mutex_unlock(&tty->termios_mutex);
+ return 0;
}
+#endif
+
+
#ifdef TIOCGETP
/*
* These are deprecated, but there is limited support..
@@ -671,7 +738,7 @@ static void set_sgflags(struct ktermios *termios, int flags)
* Updates a terminal from the legacy BSD style terminal information
* structure.
*
- * Locking: termios_sem
+ * Locking: termios_mutex
*/
static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
@@ -849,6 +916,7 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
{
struct tty_struct *real_tty;
void __user *p = (void __user *)arg;
+ int ret = 0;
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
tty->driver->subtype == PTY_TYPE_MASTER)
@@ -884,18 +952,24 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
return set_termios(real_tty, p, TERMIOS_OLD);
#ifndef TCGETS2
case TCGETS:
+ mutex_lock(&real_tty->termios_mutex);
if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ mutex_unlock(&real_tty->termios_mutex);
+ return ret;
#else
case TCGETS:
+ mutex_lock(&real_tty->termios_mutex);
if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ mutex_unlock(&real_tty->termios_mutex);
+ return ret;
case TCGETS2:
+ mutex_lock(&real_tty->termios_mutex);
if (kernel_termios_to_user_termios((struct termios2 __user *)arg, real_tty->termios))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ mutex_unlock(&real_tty->termios_mutex);
+ return ret;
case TCSETSF2:
return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
case TCSETSW2:
@@ -913,34 +987,59 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
return set_termios(real_tty, p, TERMIOS_TERMIO);
#ifndef TCGETS2
case TIOCGLCKTRMIOS:
+ mutex_lock(&real_tty->termios_mutex);
if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ mutex_unlock(&real_tty->termios_mutex);
+ return ret;
case TIOCSLCKTRMIOS:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
+ mutex_lock(&real_tty->termios_mutex);
if (user_termios_to_kernel_termios(real_tty->termios_locked,
(struct termios __user *) arg))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ mutex_unlock(&real_tty->termios_mutex);
+ return ret;
#else
case TIOCGLCKTRMIOS:
+ mutex_lock(&real_tty->termios_mutex);
if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios_locked))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ mutex_unlock(&real_tty->termios_mutex);
+ return ret;
case TIOCSLCKTRMIOS:
if (!capable(CAP_SYS_ADMIN))
- return -EPERM;
+ ret = -EPERM;
+ mutex_lock(&real_tty->termios_mutex);
if (user_termios_to_kernel_termios_1(real_tty->termios_locked,
(struct termios __user *) arg))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ mutex_unlock(&real_tty->termios_mutex);
+ return ret;
#endif
+#ifdef TCGETX
+ case TCGETX:
+ if (real_tty->termiox == NULL)
+ return -EINVAL;
+ mutex_lock(&real_tty->termios_mutex);
+ if (copy_to_user(p, real_tty->termiox, sizeof(struct termiox)))
+ ret = -EFAULT;
+ mutex_unlock(&real_tty->termios_mutex);
+ return ret;
+ case TCSETX:
+ return set_termiox(real_tty, p, 0);
+ case TCSETXW:
+ return set_termiox(real_tty, p, TERMIOS_WAIT);
+ case TCSETXF:
+ return set_termiox(real_tty, p, TERMIOS_FLUSH);
+#endif
case TIOCGSOFTCAR:
- /* FIXME: for correctness we may need to take the termios
- lock here - review */
- return put_user(C_CLOCAL(real_tty) ? 1 : 0,
+ mutex_lock(&real_tty->termios_mutex);
+ ret = put_user(C_CLOCAL(real_tty) ? 1 : 0,
(int __user *)arg);
+ mutex_unlock(&real_tty->termios_mutex);
+ return ret;
case TIOCSSOFTCAR:
if (get_user(arg, (unsigned int __user *) arg))
return -EFAULT;
@@ -980,7 +1079,7 @@ int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
}
EXPORT_SYMBOL_GPL(tty_perform_flush);
-int n_tty_ioctl(struct tty_struct *tty, struct file *file,
+int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
unsigned long flags;
@@ -1018,13 +1117,6 @@ int n_tty_ioctl(struct tty_struct *tty, struct file *file,
return 0;
case TCFLSH:
return tty_perform_flush(tty, arg);
- case TIOCOUTQ:
- return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
- case TIOCINQ:
- retval = tty->read_cnt;
- if (L_ICANON(tty))
- retval = inq_canon(tty);
- return put_user(retval, (unsigned int __user *) arg);
case TIOCPKT:
{
int pktmode;
@@ -1050,4 +1142,4 @@ int n_tty_ioctl(struct tty_struct *tty, struct file *file,
return tty_mode_ioctl(tty, file, cmd, arg);
}
}
-EXPORT_SYMBOL(n_tty_ioctl);
+EXPORT_SYMBOL(n_tty_ioctl_helper);