diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/tty_io.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index a1b36bf545e8..5cec01c75691 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2659,6 +2659,28 @@ static int tiocsetd(struct tty_struct *tty, int __user *p) } /** + * tiocgetd - get line discipline + * @tty: tty device + * @p: pointer to user data + * + * Retrieves the line discipline id directly from the ldisc. + * + * Locking: waits for ldisc reference (in case the line discipline + * is changing or the tty is being hungup) + */ + +static int tiocgetd(struct tty_struct *tty, int __user *p) +{ + struct tty_ldisc *ld; + int ret; + + ld = tty_ldisc_ref_wait(tty); + ret = put_user(ld->ops->num, p); + tty_ldisc_deref(ld); + return ret; +} + +/** * send_break - performed time break * @tty: device to break on * @duration: timeout in mS @@ -2884,7 +2906,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) case TIOCGSID: return tiocgsid(tty, real_tty, p); case TIOCGETD: - return put_user(tty->ldisc->ops->num, (int __user *)p); + return tiocgetd(tty, p); case TIOCSETD: return tiocsetd(tty, p); case TIOCVHANGUP: |