Revert "TTY: pty, remove superfluous ptm test"

This reverts commit a50f724a432997321cabb6c9e665c28e34850f78.

Sasha reported that this causes problems, so revert it.

Cc: Alan Cox <alan@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index ddec9f3c3396..d505837b3478 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -54,7 +54,10 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
         wake_up_interruptible(&tty->link->write_wait);
         if (tty->driver->subtype == PTY_TYPE_MASTER) {
                 set_bit(TTY_OTHER_CLOSED, &tty->flags);
-                devpts_pty_kill(tty->link);
+#ifdef CONFIG_UNIX98_PTYS
+                if (tty->driver == ptm_driver)
+                        devpts_pty_kill(tty->link);
+#endif
                 tty_unlock();
                 tty_vhangup(tty->link);
                 tty_lock();