From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756442Ab2DMTYY (ORCPT ); Fri, 13 Apr 2012 15:24:24 -0400 Received: from cantor2.suse.de ([195.135.220.15]:58894 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755927Ab2DMTYX convert rfc822-to-8bit (ORCPT ); Fri, 13 Apr 2012 15:24:23 -0400 Subject: [PATCH][RESEND] do not redefine userspace's NULL #define From: Lubos Lunak To: Linus Torvalds Cc: Andrew Morton , linux-kernel@vger.kernel.org, Arnd Bergmann Date: Fri, 13 Apr 2012 21:24:20 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <201204132124.21294.l.lunak@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 override what the compiler provides. Keep the #define conditionally, in order to keep the headers self-contained. Signed-off-by: Luboš Luňák --- There have been no further comments after this last version, and I do not see how this change should affect anything in either kernel builds or userspace builds, except for fixing the issue of overriding the proper NULL definition, so I consider this the proper and safe fix. include/linux/stddef.h | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/include/linux/stddef.h b/include/linux/stddef.h index 6a40c76..ce225a9 100644 --- a/include/linux/stddef.h +++ b/include/linux/stddef.h @@ -3,12 +3,13 @@ #include -#undef NULL +#ifndef NULL #if defined(__cplusplus) #define NULL 0 #else #define NULL ((void *)0) #endif +#endif #ifdef __KERNEL__ -- 1.7.7 -- Lubos Lunak l.lunak@suse.cz