tty: Fix hangup race with TIOCSETD ioctl

The hangup may already have happened; check for that state also.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 4 deletions

diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 31bd45a2d16b..5819667f5bdb 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -546,10 +546,8 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
         old_ldisc = tty->ldisc;
         tty_lock(tty);
 
-        /* FIXME: for testing only */
-        WARN_ON(test_bit(TTY_HUPPED, &tty->flags));
-
-        if (test_bit(TTY_HUPPING, &tty->flags)) {
+        if (test_bit(TTY_HUPPING, &tty->flags) ||
+            test_bit(TTY_HUPPED, &tty->flags)) {
                 /* We were raced by the hangup method. It will have stomped
                    the ldisc data and closed the ldisc down */
                 tty_ldisc_enable_pair(tty, o_tty);