From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from pfepa.post.tele.dk ([195.41.46.235]:56391 "EHLO pfepa.post.tele.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750885AbZFDKgx (ORCPT ); Thu, 4 Jun 2009 06:36:53 -0400 Date: Thu, 4 Jun 2009 12:39:09 +0200 From: Sam Ravnborg Subject: Re: [Patch 1/2] kbuild: two trivial fixes for check headers Message-ID: <20090604103909.GA10102@uranus.ravnborg.org> References: <20090604080406.7005.27662.sendpatchset@localhost.localdomain> <20090604091519.GA9571@uranus.ravnborg.org> <4A27927E.9090800@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A27927E.9090800@redhat.com> Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Amerigo Wang Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, linux-kbuild@vger.kernel.org On Thu, Jun 04, 2009 at 05:23:10PM +0800, Amerigo Wang wrote: > Sam Ravnborg wrote: > >On Thu, Jun 04, 2009 at 04:01:52AM -0400, Amerigo Wang wrote: > > > >>Remove a useless 'extern' in an exported header. > >>Fix a comment headers_check.pl. > >> > > > >These two patches has nothing in commom. > > > > They are both about kernel headers stuff. > > > > >>Signed-off-by: WANG Cong > >>Cc: Sam Ravnborg > >> > >>------ > >>diff --git a/include/mtd/jffs2-user.h b/include/mtd/jffs2-user.h > >>index fa94b0e..10dc7ef 100644 > >>--- a/include/mtd/jffs2-user.h > >>+++ b/include/mtd/jffs2-user.h > >>@@ -18,7 +18,7 @@ > >> #undef je32_to_cpu > >> #undef jemode_to_cpu > >> > >>-extern int target_endian; > >>+int target_endian; > >> > > > >You now declare a global variable named target_endian each time you > >include this file - which is wrong. > > > Why? 'make headers_check' complains about it. Rightfully is does... But is think it is a prototype of a function. But think about it - it does not makes sense to have an extern declarationof a variable in an exported header. There is no way that userspace can access this variable from user-space and therefore the declaration of the variable needs to be moved to a kernel-only header file. So if you touch this I would ask you not to consider a single line in jffs-user.h - but rather take a critiacal look at the whole file and fix any issues there is. And then to send it to the mtd people (dwmw2). I did not look at the file but just looking at yout patch the "undef jemode_to_cpu" looks fishy in an exported header. Sam