From 03c618afa3c19fe4574a5bc45eec09fd0b1d5990 Mon Sep 17 00:00:00 2001
From: Damien Miller <djm@mindrot.org>
Date: Fri, 26 Oct 2007 16:45:32 +1000
Subject: [PATCH]    - otto@cvs.openbsd.org 2005/11/25 08:06:25     
 [openbsd-compat/sys-queue.h]      Introduce debugging aid for queue macros.
 Disabled by default; but      developers are encouraged to run with this
 enabled.      ok krw@ fgsch@ deraadt@

---
 ChangeLog                  |  7 ++++++-
 openbsd-compat/sys-queue.h | 21 ++++++++++++++++++++-
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 238e6c45a..33798ba94 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -118,6 +118,11 @@
      [openbsd-compat/sys-queue.h]
      Some uvm problem is being exposed with the more strict macros.
      Revert until we've found out what's causing the panics.
+   - otto@cvs.openbsd.org 2005/11/25 08:06:25
+     [openbsd-compat/sys-queue.h]
+     Introduce debugging aid for queue macros. Disabled by default; but
+     developers are encouraged to run with this enabled.
+     ok krw@ fgsch@ deraadt@
  - (djm) [regress/sftp-cmds.sh]
    Use more restrictive glob to pick up test files from /bin - some platforms
    ship broken symlinks there which could spoil the test.
@@ -3394,4 +3399,4 @@
    OpenServer 6 and add osr5bigcrypt support so when someone migrates
    passwords between UnixWare and OpenServer they will still work. OK dtucker@
 
-$Id: ChangeLog,v 1.4790 2007/10/26 06:44:27 djm Exp $
+$Id: ChangeLog,v 1.4791 2007/10/26 06:45:32 djm Exp $
diff --git a/openbsd-compat/sys-queue.h b/openbsd-compat/sys-queue.h
index db747befa..7d231bca8 100644
--- a/openbsd-compat/sys-queue.h
+++ b/openbsd-compat/sys-queue.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: queue.h,v 1.30 2005/10/25 06:37:47 otto Exp $	*/
+/*	$OpenBSD: queue.h,v 1.31 2005/11/25 08:06:25 otto Exp $	*/
 /*	$NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $	*/
 
 /*
@@ -167,6 +167,12 @@
  * For details on the use of these macros, see the queue(3) manual page.
  */
 
+#ifdef QUEUE_MACRO_DEBUG
+#define _Q_INVALIDATE(a) (a) = ((void *)-1)
+#else
+#define _Q_INVALIDATE(a)
+#endif
+
 /*
  * Singly-linked List definitions.
  */
@@ -236,6 +242,7 @@ struct {								\
 			curelm = curelm->field.sle_next;		\
 		curelm->field.sle_next =				\
 		    curelm->field.sle_next->field.sle_next;		\
+		_Q_INVALIDATE((elm)->field.sle_next);			\
 	}								\
 } while (0)
 
@@ -303,6 +310,8 @@ struct {								\
 		(elm)->field.le_next->field.le_prev =			\
 		    (elm)->field.le_prev;				\
 	*(elm)->field.le_prev = (elm)->field.le_next;			\
+	_Q_INVALIDATE((elm)->field.le_prev);				\
+	_Q_INVALIDATE((elm)->field.le_next);				\
 } while (0)
 
 #define LIST_REPLACE(elm, elm2, field) do {				\
@@ -311,6 +320,8 @@ struct {								\
 		    &(elm2)->field.le_next;				\
 	(elm2)->field.le_prev = (elm)->field.le_prev;			\
 	*(elm2)->field.le_prev = (elm2);				\
+	_Q_INVALIDATE((elm)->field.le_prev);				\
+	_Q_INVALIDATE((elm)->field.le_next);				\
 } while (0)
 
 /*
@@ -465,6 +476,8 @@ struct {								\
 	else								\
 		(head)->tqh_last = (elm)->field.tqe_prev;		\
 	*(elm)->field.tqe_prev = (elm)->field.tqe_next;			\
+	_Q_INVALIDATE((elm)->field.tqe_prev);				\
+	_Q_INVALIDATE((elm)->field.tqe_next);				\
 } while (0)
 
 #define TAILQ_REPLACE(head, elm, elm2, field) do {			\
@@ -475,6 +488,8 @@ struct {								\
 		(head)->tqh_last = &(elm2)->field.tqe_next;		\
 	(elm2)->field.tqe_prev = (elm)->field.tqe_prev;			\
 	*(elm2)->field.tqe_prev = (elm2);				\
+	_Q_INVALIDATE((elm)->field.tqe_prev);				\
+	_Q_INVALIDATE((elm)->field.tqe_next);				\
 } while (0)
 
 /*
@@ -575,6 +590,8 @@ struct {								\
 	else								\
 		(elm)->field.cqe_prev->field.cqe_next =			\
 		    (elm)->field.cqe_next;				\
+	_Q_INVALIDATE((elm)->field.cqe_prev);				\
+	_Q_INVALIDATE((elm)->field.cqe_next);				\
 } while (0)
 
 #define CIRCLEQ_REPLACE(head, elm, elm2, field) do {			\
@@ -588,6 +605,8 @@ struct {								\
 		(head).cqh_first = (elm2);				\
 	else								\
 		(elm2)->field.cqe_prev->field.cqe_next = (elm2);	\
+	_Q_INVALIDATE((elm)->field.cqe_prev);				\
+	_Q_INVALIDATE((elm)->field.cqe_next);				\
 } while (0)
 
 #endif	/* !_FAKE_QUEUE_H_ */