1 files changed, 15 insertions, 8 deletions

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index bfe9ad85b362..21ffcce16927 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1256,7 +1256,8 @@ static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *
 static int tty_reopen(struct tty_struct *tty)
 {
         struct tty_driver *driver = tty->driver;
-        int retval;
+        struct tty_ldisc *ld;
+        int retval = 0;
 
         if (driver->type == TTY_DRIVER_TYPE_PTY &&
             driver->subtype == PTY_TYPE_MASTER)
@@ -1268,13 +1269,18 @@ static int tty_reopen(struct tty_struct *tty)
         if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN))
                 return -EBUSY;
 
-        retval = tty_ldisc_lock(tty, 5 * HZ);
-        if (retval)
-                return retval;
+        ld = tty_ldisc_ref_wait(tty);
+        if (ld) {
+                tty_ldisc_deref(ld);
+        } else {
+                retval = tty_ldisc_lock(tty, 5 * HZ);
+                if (retval)
+                        return retval;
 
-        if (!tty->ldisc)
-                retval = tty_ldisc_reinit(tty, tty->termios.c_line);
-        tty_ldisc_unlock(tty);
+                if (!tty->ldisc)
+                        retval = tty_ldisc_reinit(tty, tty->termios.c_line);
+                tty_ldisc_unlock(tty);
+        }
 
         if (retval == 0)
                 tty->count++;
@@ -2183,7 +2189,8 @@ static int tiocsti(struct tty_struct *tty, char __user *p)
         ld = tty_ldisc_ref_wait(tty);
         if (!ld)
                 return -EIO;
-        ld->ops->receive_buf(tty, &ch, &mbz, 1);
+        if (ld->ops->receive_buf)
+                ld->ops->receive_buf(tty, &ch, &mbz, 1);
         tty_ldisc_deref(ld);
         return 0;
 }