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=-11.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no 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 EF554C433E1 for ; Sun, 12 Jul 2020 23:34:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CDE4A206B6 for ; Sun, 12 Jul 2020 23:34:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="pBpXJX53" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728273AbgGLXex (ORCPT ); Sun, 12 Jul 2020 19:34:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59862 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727998AbgGLXew (ORCPT ); Sun, 12 Jul 2020 19:34:52 -0400 Received: from mail-ej1-x644.google.com (mail-ej1-x644.google.com [IPv6:2a00:1450:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99AA6C08C5DD for ; Sun, 12 Jul 2020 16:34:52 -0700 (PDT) Received: by mail-ej1-x644.google.com with SMTP id w6so13382599ejq.6 for ; Sun, 12 Jul 2020 16:34:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=LVOtLwv/Cvl11tUYp50SksGWhQhY11SC0NIkGuc8zKg=; b=pBpXJX539broCTWH17WgpJDxoLP0paWSlvb8A7h3fxHZadJbhqRCNtCFP25mX7XEJ4 /kwaDuWKopj4I8eO8SAvDGZq6F9j25nSGRAO0y6X2NGnu7izoh9SZwvHn6KFIILHenua VZeZFZ0bZYIFUV+EEZeOEkkM7qjxY5RJIoRAIP4Ic1GB+xDjTjYg3z0lEPuNawED7EbA MonmBQTmlvtQCqFgEnrnwFndAHCUOPLKAGIG3XWpeW0/Qr4qA0bZxFzdTlAkI2KH7b0F rBajQRa/6JbzOq5B4AwXzh5PM1ZTZhssUaqSkDgJ7Yz0lPtz7xwa3hLHTGAXQMnzERV6 /O1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=LVOtLwv/Cvl11tUYp50SksGWhQhY11SC0NIkGuc8zKg=; b=RTKKKbWVu0aq/bIww8dT4MZSIS1VrwET0siSM5TRFheWndOKtMfiquvGZym4tkyyPl wmbPM3KgHtmlqwlvNpW76cn289rvVhMMSG5d8+bVK/1qLN72quX+MxWqL6JHZEjcTK/c 08Bg9jYJuzPSgww3ILh0LnwoMHvJE4E0IZq3i8DC3GgSIgt1C+HcNuVT/XvZyc3r0B99 +Sw0Zo+Vx5ZqumAlb/7Pb/HYJ1q8xWUoHZf4G4gQ7ZHo3W6A+r0QZ8YphICwTgHrXVPS mjo7YWhpup0mG1s0FvWwZFuLiStyyVMb36Pi4erIrlBHfQJcMUA99QjJV0kcJjiLrO8r EDeg== X-Gm-Message-State: AOAM531fd21SRuS9Iig93IJqHGmGPwoZ0I3BgPrmCbRsPQZxRl5DhngZ MyQR2Hp+zTjLyJ2i9ZzQm9f3mxFzHORVL9gB5a0yPQ== X-Google-Smtp-Source: ABdhPJytFy6lsxbxptEBJHanuAZiQiJRjagWMLPmEYrRnXLJYMLE9doc2W4BiVdJO1Ek3tqEEHDclPE0n0pEuhpOHu8= X-Received: by 2002:a17:906:94c4:: with SMTP id d4mr69283452ejy.232.1594596890894; Sun, 12 Jul 2020 16:34:50 -0700 (PDT) MIME-Version: 1.0 References: <20200624203200.78870-1-samitolvanen@google.com> <671d8923-ed43-4600-2628-33ae7cb82ccb@molgen.mpg.de> In-Reply-To: <671d8923-ed43-4600-2628-33ae7cb82ccb@molgen.mpg.de> From: Sami Tolvanen Date: Sun, 12 Jul 2020 16:34:39 -0700 Message-ID: Subject: Re: [PATCH 00/22] add support for Clang LTO To: Paul Menzel Cc: Masahiro Yamada , Will Deacon , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , Nick Desaulniers , clang-built-linux , Kernel Hardening , linux-arch , linux-arm-kernel , linux-kbuild , LKML , linux-pci@vger.kernel.org, X86 ML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jul 11, 2020 at 9:32 AM Paul Menzel wrote: > Thank you very much for sending these changes. > > Do you have a branch, where your current work can be pulled from? Your > branch on GitHub [1] seems 15 months old. The clang-lto branch is rebased regularly on top of Linus' tree. GitHub just looks at the commit date of the last commit in the tree, which isn't all that informative. > Out of curiosity, I applied the changes, allowed the selection for i386 > (x86), and with Clang 1:11~++20200701093119+ffee8040534-1~exp1 from > Debian experimental, it failed with `Invalid absolute R_386_32 > relocation: KERNEL_PAGES`: I haven't looked at getting this to work on i386, which is why we only select ARCH_SUPPORTS_LTO for x86_64. I would expect there to be a few issues to address. > > arch/x86/tools/relocs vmlinux > arch/x86/boot/compressed/vmlinux.relocs;arch/x86/tools/relocs --abs-relocs vmlinux > > Invalid absolute R_386_32 relocation: KERNEL_PAGES KERNEL_PAGES looks like a constant, so it's probably safe to ignore the absolute relocation in tools/relocs.c. Sami