From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 317B2C4321D for ; Wed, 22 Aug 2018 20:50:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D68E9208CC for ; Wed, 22 Aug 2018 20:50:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D68E9208CC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=perches.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727251AbeHWARD (ORCPT ); Wed, 22 Aug 2018 20:17:03 -0400 Received: from smtprelay0222.hostedemail.com ([216.40.44.222]:48757 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726581AbeHWARC (ORCPT ); Wed, 22 Aug 2018 20:17:02 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay02.hostedemail.com (Postfix) with ESMTP id BFB055B3B; Wed, 22 Aug 2018 20:50:35 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: birds46_4dd97befa159 X-Filterd-Recvd-Size: 4313 Received: from XPS-9350.home (unknown [47.151.153.53]) (Authenticated sender: joe@perches.com) by omf05.hostedemail.com (Postfix) with ESMTPA; Wed, 22 Aug 2018 20:50:33 +0000 (UTC) Message-ID: <39b6242771fd80fe19104c8a057bcc6afc0e41e5.camel@perches.com> Subject: Re: [PATCH] compiler-gcc: get back Clang build From: Joe Perches To: Nick Desaulniers , asmadeus@codewreck.org Cc: Masahiro Yamada , Kees Cook , Linus Torvalds , Jonathan Corbet , Arnd Bergmann , dwmw@amazon.co.uk, LKML , Thomas Gleixner , Will Deacon , Geert Uytterhoeven , Ingo Molnar , Andrew Morton Date: Wed, 22 Aug 2018 13:50:32 -0700 In-Reply-To: References: <1534834088-15835-1-git-send-email-yamada.masahiro@socionext.com> <20180821123832.GA19034@nautica> <20180822041646.GA21716@nautica> <78396ba82562326f4b3a395a63e3e8dc38d608b2.camel@perches.com> <20180822043230.GA26654@nautica> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.28.1-2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2018-08-22 at 11:31 -0700, Nick Desaulniers wrote: > On Tue, Aug 21, 2018 at 9:32 PM Dominique Martinet > wrote: > > > > Joe Perches wrote on Tue, Aug 21, 2018: > > > On Wed, 2018-08-22 at 06:16 +0200, Dominique Martinet wrote: > > > > I think that could work, but at the point making a separate > > > > compiler-common.h and not including compiler-gcc.h for clang sounds > > > > better to me... More importantly here, either solution sound complex > > > > enough to require more than a few days and proper testing for all archs > > > > etc when compared to the partial revert we have here. > > > > > > The immediate need for a partial revert seems unnecessary as > > > clang hasn't really worked for a couple releases now. > > > > Sorry for repeating myself, clang is used by bcc for compiling BPF > > programs (e.g. bpf_module_create_c_from_string() or any similar function > > will use the clang libs to compile the bpf program with linux headers), > > and this has always been working because it's not using our makefiles. > > > > This broke today in master and I only joined this thread after looking > > at why the build started failing today and noticing this patch, it > > definitely hasn't been broken for two releases, or I wouldn't be here > > with this timing :) > > > > > > > The separate compiler file changes are much more sensible, > > > even if it takes a few days. > > > > A few days are fine, but I think some form of fix in 4.19-rc1 would be > > good. > > > > I'll stop taking your time now, but I think you are/were underestimating > > how many people use clang with the linux kernel headers indirectly. > > BPF is a well-used tool :) > > Hi Dominique, > I'm currently testing a fix in > https://github.com/ClangBuiltLinux/linux/commit/1f89ae7622c26b8131f42f3a362d6ef41b88a595, > can you please share with me your steps to test/verify that the patch > fixes the issue for eBPF? I'll go talk to a co-worker who know more > about eBPF, but I've not yet done anything with it. A mild suggestion about the patch would be to break it up into 2 patches to improve how people read and review them. 1 include/linux/compiler-* 2 everything else Yes, some kernel configs might not build properly between 1 and 2 but that likely doesn't matter as those configs probably don't build before 1 either. Perhaps the test in arch/arm/kernel/asm-offsets.c for incompatible gcc compiler versions from 4.8.0 to 4.8.2 should be moved to compiler-gcc.h. > Also, does anyone know who I should talk to about ICC testing? No clue