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=-5.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 3FD91C35DF3 for ; Tue, 25 Feb 2020 04:25:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1827422464 for ; Tue, 25 Feb 2020 04:25:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Os+w8rwO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728944AbgBYEZV (ORCPT ); Mon, 24 Feb 2020 23:25:21 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:36201 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728888AbgBYEZU (ORCPT ); Mon, 24 Feb 2020 23:25:20 -0500 Received: by mail-pg1-f196.google.com with SMTP id d9so6243732pgu.3 for ; Mon, 24 Feb 2020 20:25:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=V3nWmStnvPZrHNcjnbGk3TD16rtsFo3zS9ml9/tupfA=; b=Os+w8rwORbsSvA9/rgOQxjk9S+07cf3g1CvGuWAM6uFAwhSWbDL7GHzGIaudmk2yf2 36n05PVA5rv0QjBX0cF2vNZ+wPMVub0+cIrLBXwOKMJToxcz0Q6KaSL8zXR1GIDslTJ/ 2raWdrHck/2t57HY4PwnZ6fnNZy/Q/hQMZfEc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=V3nWmStnvPZrHNcjnbGk3TD16rtsFo3zS9ml9/tupfA=; b=A8P7nmlsNfzGm/2UJocrSUN+N9Gj23ci0S5IvnkeTCqcJELP7/UAXMsyjBTGHhgj4W OyiSXrED1m2ntfK6Qqhm0rjspToU0ri3H2q/flHQwktfHCSraqO3TKagTmYEmY+V9bNn X4SxtehLWmMUtSW0w58/wMoZye1061NuhT3SmxgVBsfE+4THNvCXr2nXYDvjP/GZerVG Vd6tC2BSd7syDCxzySC/u23zkX6h98mEvE0MkWGJ1fk30TnsZQ1X6noezTTSO6HJjRei qNLy11h2spvLnzR6JbfR/62SNX1kMa/gwa/RomZlZs9tKSjcpBjyVhhf6cReJQhVqO/1 52PQ== X-Gm-Message-State: APjAAAUVKWMxoTAffQlhykXq/dfCw9wwaVGKJOgWp63v9+9jzGKyHbdw iVrY7vWRatMPPvBwW82n/8cZGM2X5Jo= X-Google-Smtp-Source: APXvYqzUFoExhaYfwO6l6Dm9CbWXqNVrmAC1C4GQAZQIVOP0sF2hXsiJMAhOUZJQp9U5i4eYLsk5tw== X-Received: by 2002:a65:6718:: with SMTP id u24mr57085768pgf.289.1582604720027; Mon, 24 Feb 2020 20:25:20 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id x65sm15469700pfb.171.2020.02.24.20.25.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Feb 2020 20:25:18 -0800 (PST) Date: Mon, 24 Feb 2020 20:25:17 -0800 From: Kees Cook To: Nathan Chancellor Cc: Nick Desaulniers , corbet@lwn.net, masahiroy@kernel.org, Michal Marek , linux-kbuild@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com Subject: Re: [PATCH] Documentation/llvm: add documentation on building w/ Clang/LLVM Message-ID: <202002242019.A9F519A33A@keescook> References: <20200224174129.2664-1-ndesaulniers@google.com> <202002242003.870E5F80@keescook> <20200225041643.GA17425@ubuntu-m2-xlarge-x86> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200225041643.GA17425@ubuntu-m2-xlarge-x86> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 24, 2020 at 09:16:43PM -0700, Nathan Chancellor wrote: > I think the clang one should be added in a separate patch that > solidifies that in include/linux/compiler-clang.h with a CLANG_VERSION > macro and version check, like in include/linux/compiler-gcc.h. Sounds good. > ld.lld's minimum version should also be 9, what is the blocking issue > that makes it 11? I think I've mostly got future patches on my mind. lld before 11 will blow up on this: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/log/?h=build/link-time (but I haven't sent this patch yet since I didn't want to break lld until it was fixed, which it is now, but I got distracted by other stuff). Additionally there will be LTO, but LTO will be version-checked. Then I was thinking about the orphan section handling, and there is very clearly more work to be done there too... (i.e. the synthesized sections get reported by the orphan warning before they're actually processed by DISCARD is some cases -- I still need to isolate the behavior and open a bug.) -- Kees Cook