From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753252AbcAVLT5 (ORCPT ); Fri, 22 Jan 2016 06:19:57 -0500 Received: from mail.skyhub.de ([78.46.96.112]:34665 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752763AbcAVLTs (ORCPT ); Fri, 22 Jan 2016 06:19:48 -0500 Date: Fri, 22 Jan 2016 12:19:18 +0100 From: Borislav Petkov To: "H. Peter Anvin" , David Howells Cc: Andy Lutomirski , Brian Gerst , X86 ML , LKML Subject: Re: [PATCH 1/5] x86/cpufeature: Carve out X86_FEATURE_* Message-ID: <20160122111918.GA9806@pd.tnic> References: <1453401286-26966-1-git-send-email-bp@alien8.de> <1453401286-26966-2-git-send-email-bp@alien8.de> <56A12A02.60607@zytor.com> <20160121190340.GG21930@pd.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20160121190340.GG21930@pd.tnic> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 21, 2016 at 08:03:40PM +0100, Borislav Petkov wrote: > On Thu, Jan 21, 2016 at 10:57:06AM -0800, H. Peter Anvin wrote: > > On 01/21/16 10:34, Borislav Petkov wrote: > > > +#ifndef _ASM_X86_REQUIRED_FEATURES_H > > > > Why do we have all these include guards at the point of the #include? > > This is not standard procedure. > > Some uapi monkey business: > > abbf1590de22 ("UAPI: Partition the header include path sets and add uapi/ header directories") > > The funny thing is, the headers themselves have the guards too. I'll try > to remove them to see what breaks. Ah, here it is: In file included from arch/x86/boot/mkcpustr.c:20:0: arch/x86/boot/../include/asm/cpufeatures.h:4:35: fatal error: asm/required-features.h: No such file or directory compilation terminated. make[1]: *** [arch/x86/boot/mkcpustr] Error 1 make[1]: *** Waiting for unfinished jobs.... make: *** [bzImage] Error 2 make: *** Waiting for unfinished jobs.... That's when you remove the #ifndef guards. And I think the commit above does this special dancing to keep cpufeature.h a kernel-only header and not make it an uapi one. David, am I close? Thanks. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.