Prevent yet another staircase effect bug in the console device.

Even though I thought I fixed the staircase issue (and I was no longer
able to reproduce it), I got some reports of the issue still being
there. It turns out the staircase effect still occurred when
/dev/console was kept open while killing the getty on the same TTY
(ttyv0).

For some reason I can't figure out how the old TTY code dealt with that,
so I assume the issue has always been there. I only exposed it more by
merging consolectl with ttyv0, which means that the issue was present,
even on systems without a serial console.

I'm now marking the console device as being closed when closing the
regular TTY device node. This means that when the getty shuts down,
init(8) will open /dev/console, which means the termios attributes will
always be reset in this case.

1 files changed, 7 insertions, 7 deletions

diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index 162ae37..4a0905a 100644
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -322,14 +322,14 @@ ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
 	 * console.
 	 */
 	MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
-	if (dev == dev_console)
+	if (dev == dev_console) {
 		tp->t_flags &= ~TF_OPENED_CONS;
-	else
-		tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
-
-	if (tp->t_flags & TF_OPENED) {
-		tty_unlock(tp);
-		return (0);
+		if (tp->t_flags & TF_OPENED) {
+			tty_unlock(tp);
+			return (0);
+		}
+	} else {
+		tp->t_flags &= ~TF_OPENED;
 	}
 
 	/*