qubes-linux-kernel/patches.fixes/xencons_close_deadlock.patch

--- linux-2.6.38.3/drivers/xen/console/console.c.orig	2011-07-21 13:20:34.120001602 +0200
+++ linux-2.6.38.3/drivers/xen/console/console.c	2011-07-21 13:36:14.848001956 +0200
@@ -618,7 +618,12 @@ static void xencons_close(struct tty_str
 	if (DUMMY_TTY(tty))
 		return;
 
+	/* We are called under tty_lock(). As other functions in tty core
+	obtain locks in tty_mutex,tty_lock order, we must do the same to
+	avoid a deadlock. Thus we must first tty_unlock(), and then lock. */
+	tty_unlock();
 	mutex_lock(&tty_mutex);
+	tty_lock();
 
 	if (tty->count != 1) {
 		mutex_unlock(&tty_mutex);