From 98ef6ed422a98c5a23f580fa08cf563a05f9a9fe Mon Sep 17 00:00:00 2001
From: Peter Wemm <peter@FreeBSD.org>
Date: Tue, 23 Dec 2003 02:34:25 +0000
Subject: [PATCH] Don peril sensitive sunglasses and set NULL to an actual
 pointer type, but *only* for the kernel.  We can do this because the kernel
 is not a standard C application environment.  This would have stopped the
 recent mtx_* arg NULL/MTX_DEF mixups from going unnoticed for so long.

---
 sys/sys/_null.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sys/sys/_null.h b/sys/sys/_null.h
index 36552546e2b..6059f578590 100644
--- a/sys/sys/_null.h
+++ b/sys/sys/_null.h
@@ -28,10 +28,14 @@
 
 #ifndef NULL
 
+#ifdef _KERNEL
+#define	NULL	(void *)0
+#else
 #if defined(__LP64__) || defined(__amd64__)
 #define	NULL	0L
 #else
 #define	NULL	0
 #endif
+#endif	/* _KERNEL */
 
 #endif