diff options
Diffstat (limited to 'drivers/char/tty_ioctl.c')
| -rw-r--r-- | drivers/char/tty_ioctl.c | 212 |
1 files changed, 152 insertions, 60 deletions
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c index bf34e459742..a408c8e487e 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); |