svn commit: r295392 - stable/10/sys/kern

[Konstantin Belousov]

Author: kib
Date: Mon Feb  8 11:15:36 2016
New Revision: 295392
URL: https://svnweb.freebsd.org/changeset/base/295392

Log:
  MFC r294735:
  Don't allow opening the callout device when the callin device is already
  open (in disguise as the console device).
  
  Approved by:	re (gjb)

Modified:
  stable/10/sys/kern/tty.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/kern/tty.c
==============================================================================
--- stable/10/sys/kern/tty.c	Mon Feb  8 10:54:27 2016	(r295391)
+++ stable/10/sys/kern/tty.c	Mon Feb  8 11:15:36 2016	(r295392)
@@ -266,10 +266,10 @@ ttydev_open(struct cdev *dev, int oflags
 
 	/*
 	 * Make sure the "tty" and "cua" device cannot be opened at the
-	 * same time.
+	 * same time.  The console is a "tty" device.
 	 */
 	if (TTY_CALLOUT(tp, dev)) {
-		if (tp->t_flags & TF_OPENED_IN) {
+		if (tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) {
 			error = EBUSY;
 			goto done;
 		}
@@ -322,6 +322,8 @@ ttydev_open(struct cdev *dev, int oflags
 		tp->t_flags |= TF_OPENED_OUT;
 	else
 		tp->t_flags |= TF_OPENED_IN;
+	MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
+	    (tp->t_flags & TF_OPENED_OUT) == 0);
 
 done:	tp->t_flags &= ~TF_OPENCLOSE;
 	cv_broadcast(&tp->t_dcdwait);
@@ -342,7 +344,8 @@ ttydev_close(struct cdev *dev, int fflag
 	 * Don't actually close the device if it is being used as the
 	 * console.
 	 */
-	MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
+	MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
+	    (tp->t_flags & TF_OPENED_OUT) == 0);
 	if (dev == dev_console)
 		tp->t_flags &= ~TF_OPENED_CONS;
 	else