[PATCH] do not export kernel's NULL #define to userspace

From: Lubos Lunak
Date: Wed Mar 21 2012 - 09:08:23 EST


GCC's NULL is actually __null, which allows detecting some questionable
NULL usage and warn about it. Moreover each platform/compiler should have
its own stddef.h anyway (which is different from linux/stddef.h).
So there's no good reason to leak kernel's NULL to userspace and
override what the compiler provides.

Signed-off-by: LuboÅ LuÅÃk <l.lunak@xxxxxxx>
---
include/linux/stddef.h | 8 ++------
1 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/include/linux/stddef.h b/include/linux/stddef.h
index 6a40c76..1747b67 100644
--- a/include/linux/stddef.h
+++ b/include/linux/stddef.h
@@ -3,14 +3,10 @@

#include <linux/compiler.h>

+#ifdef __KERNEL__
+
#undef NULL
-#if defined(__cplusplus)
-#define NULL 0
-#else
#define NULL ((void *)0)
-#endif
-
-#ifdef __KERNEL__

enum {
false = 0,
--
1.7.3.4
--
Lubos Lunak
l.lunak@xxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/