tty: Fix UML console breakage

peterhurley · gregkh · commit da5a0fc6743d · 2016-03-31T17:14:14.000-07:00
User-Mode Linux supplies an alternate TTY_MAJOR driver for stdio console, so the noctty check in tty_open() must apply only to VT driver tty0 devnode and not the UML console driver tty0 devnode. Fixes: 11e1d4a ("tty: Consolidate noctty checks in tty_open()") Reported-by: Richard Weinberger <richard.weinberger@gmail.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
@@ -2158,7 +2158,7 @@ static int tty_open(struct inode *inode, struct file *filp)
 	read_lock(&tasklist_lock);
 	spin_lock_irq(&current->sighand->siglock);
 	noctty = (filp->f_flags & O_NOCTTY) ||
-			device == MKDEV(TTY_MAJOR, 0) ||
+			(IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) ||
 			device == MKDEV(TTYAUX_MAJOR, 1) ||
 			(tty->driver->type == TTY_DRIVER_TYPE_PTY &&
 			 tty->driver->subtype == PTY_TYPE_MASTER);
