From 5e27a60372eac27bb8a30dd363b2e0986aa564f6 Mon Sep 17 00:00:00 2001
From: Andriy Gapon <avg@FreeBSD.org>
Date: Sun, 4 Dec 2011 21:27:41 +0000
Subject: [PATCH] critical_exit: ignore td_owepreempt if kdb_active is set

calling mi_switch in such a context results in a recursion via
kdb_switch

Suggested by:	jhb
Reviewed by:	jhb
MFC after:	5 weeks
---
 sys/kern/kern_switch.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/kern/kern_switch.c b/sys/kern/kern_switch.c
index 93cbf7b54db..885dc22cea7 100644
--- a/sys/kern/kern_switch.c
+++ b/sys/kern/kern_switch.c
@@ -200,7 +200,7 @@ critical_exit(void)
 
 	if (td->td_critnest == 1) {
 		td->td_critnest = 0;
-		if (td->td_owepreempt) {
+		if (td->td_owepreempt && !kdb_active) {
 			td->td_critnest = 1;
 			thread_lock(td);
 			td->td_critnest--;