From 88c4e380c406520b75512d25ec432486acf95ab5 Mon Sep 17 00:00:00 2001
From: dd
Date: Wed, 10 Jul 2002 03:29:38 +0000
Subject: Add a VT_LOCKSWITCH ioctl that disallows vty switching. Something
like this can be emulated by VT_SETMODEing to VT_PROCESS and never releasing
the vty, but this has a number of problems, most notably that a process must
stay resident for the lock to be in effect.
Reviewed by: roam, sheldonh
---
sys/dev/syscons/syscons.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
(limited to 'sys/dev/syscons/syscons.c')
diff --git a/sys/dev/syscons/syscons.c b/sys/dev/syscons/syscons.c
index 02c771a..09f35bb 100644
--- a/sys/dev/syscons/syscons.c
+++ b/sys/dev/syscons/syscons.c
@@ -981,6 +981,13 @@ scioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td)
*(int *)data = scp->index + 1;
return 0;
+ case VT_LOCKSWITCH: /* prevent vty switching */
+ if ((*(int *)data) & 0x01)
+ sc->flags |= SC_SCRN_VTYLOCK;
+ else
+ sc->flags &= ~SC_SCRN_VTYLOCK;
+ return 0;
+
case KDENABIO: /* allow io operations */
error = suser(td);
if (error != 0)
@@ -2075,6 +2082,13 @@ sc_switch_scr(sc_softc_t *sc, u_int next_scr)
DPRINTF(5, ("sc0: sc_switch_scr() %d ", next_scr + 1));
+ /* prevent switch if previously requested */
+ if (sc->flags & SC_SCRN_VTYLOCK) {
+ sc_bell(sc->cur_scp, sc->cur_scp->bell_pitch,
+ sc->cur_scp->bell_duration);
+ return EPERM;
+ }
+
/* delay switch if the screen is blanked or being updated */
if ((sc->flags & SC_SCRN_BLANKED) || sc->write_in_progress
|| sc->blink_in_progress || sc->videoio_in_progress) {
--
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