From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Mon, 1 Nov 2010 02:38:46 +0000 (-0700)
Subject: kernel - Do not back out critical section for exchange_scr() call
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/f48559fd3cbe6d5d532ff56cc0d04c854cd30b01

kernel - Do not back out critical section for exchange_scr() call

* The critical section may be protecting a spinlock and cannot be safely
  backed out when calling exchange_scr().

* Fixes a panic.

Reported-by: rob
---

diff --git a/sys/dev/misc/syscons/syscons.c b/sys/dev/misc/syscons/syscons.c
index 20a779fd60..982ceadfc7 100644
--- a/sys/dev/misc/syscons/syscons.c
+++ b/sys/dev/misc/syscons/syscons.c
@@ -2540,9 +2540,7 @@ do_switch_scr(sc_softc_t *sc)
     lwkt_gettoken(&tty_token);
     vt_proc_alive(sc->new_scp);
 
-    crit_exit();
     exchange_scr(sc);
-    crit_enter();
     /* sc->cur_scp == sc->new_scp */
     wakeup((caddr_t)&sc->cur_scp->smode);