From: Lubos Lunak <l.lunak@suse.cz>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org
Subject: [PATCH] do not export kernel's NULL #define to userspace
Date: Wed, 21 Mar 2012 14:08:24 +0100 [thread overview]
Message-ID: <201203211408.25040.l.lunak@suse.cz> (raw)
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: Luboš Luňák <l.lunak@suse.cz>
---
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@suse.cz
next reply other threads:[~2012-03-21 13:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-21 13:08 Lubos Lunak [this message]
2012-03-21 13:32 ` [PATCH] do not export kernel's NULL #define to userspace Arnd Bergmann
2012-03-21 14:09 ` Lubos Lunak
2012-03-21 14:17 ` Arnd Bergmann
2012-03-21 18:37 ` Lubos Lunak
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=201203211408.25040.l.lunak@suse.cz \
--to=l.lunak@suse.cz \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox