diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index c3956ca022e465d2425f6ab0fdbf0b95fb48db74..b0500a0a87b86161b8cf8befcee9753ff6cda74d 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -271,10 +271,13 @@ const struct file_operations tty_ldiscs_proc_fops = { struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty) { + struct tty_ldisc *ld; + ldsem_down_read(&tty->ldisc_sem, MAX_SCHEDULE_TIMEOUT); - if (!tty->ldisc) + ld = tty->ldisc; + if (!ld) ldsem_up_read(&tty->ldisc_sem); - return tty->ldisc; + return ld; } EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait);