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=-7.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 B7823C433E2 for ; Tue, 14 Jul 2020 12:36:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 951B322409 for ; Tue, 14 Jul 2020 12:36:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="exjA6lvA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728116AbgGNMgJ (ORCPT ); Tue, 14 Jul 2020 08:36:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726354AbgGNMgI (ORCPT ); Tue, 14 Jul 2020 08:36:08 -0400 Received: from mail-io1-xd44.google.com (mail-io1-xd44.google.com [IPv6:2607:f8b0:4864:20::d44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 519CFC061755; Tue, 14 Jul 2020 05:36:08 -0700 (PDT) Received: by mail-io1-xd44.google.com with SMTP id e64so17063436iof.12; Tue, 14 Jul 2020 05:36:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc; bh=Gb+Q70LB3bQ72JL0eSnIdekJKUYUeTWGONZ+6Nqwogo=; b=exjA6lvAWxUvf1Td2gq98AcVXUNkO3OPeywwuYDfsL+Z0YPJPbs2u85bRho4FdyAYG h1Me90Y/Xi9mrbBb8IaCwjCCtYe0iU8Kdh8gvx4lPvw3ww0BSuQCAaIggiGzNrJ/rvTH NUMDgXk2hTiz164UVDp0X/EMe5UZSZk9rzOG8RZLS92wGG7i2sWIFctBkIViYipOQgok xcfHbLR2UQt/A0WzfMGMQVUKm26Utu92kngSJt91ObuRmBmWkKww8U1+XQaxchUIoULg LETQQruiS74VAz/QrOz41g7p3HeSVdiEqjGWDHkLxWa7roAfEPM+hfKFIBuOgsfaV0cy L0ew== 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:reply-to :from:date:message-id:subject:to:cc; bh=Gb+Q70LB3bQ72JL0eSnIdekJKUYUeTWGONZ+6Nqwogo=; b=RrEsTEE91Wa5ahkqfMec8OOktXXg9tpa7vfbpZfvPrtgaOiXTVTN3lHjYDhP+D+/gs PLvxwhL5vgnOmtHLDr+ij1bmS0m2FYfPO3K/LEe2xwkJx6f9D9vqLT7tPncNJE6ucaGk HB3gJMWAPDByjayaTvAcviDUKJF83bSJsPiO4F0W8d7LFja/nITv5inugh2s2BEFhQq+ /JCdaoASDY5LQFFxueP+2yAe/hwam1d1m34OT3GT26a+l1oiNqUrSMNOFhH50KWxo9w3 YIbERlv7jWfMKelNhKSOWpJZDaPV2HSJwbXRnA0MdHxE5va9F6RKoGVHcmvpHZEcKcz/ eCZA== X-Gm-Message-State: AOAM530+7GaOsg7gTlQ6o73+pA6GTpfoKEHHuoJrRuX9tJoKGeEwadnH VuJRaOLpWyxWgLg4ukGKE7IIKFyMQPO3sKMyhTuR6t7b14E= X-Google-Smtp-Source: ABdhPJy08S8ez9XwftwQn5CP8eSR816kqqnMmTFnXtvq9GDL8Kyd4FJY0vpVR/06YozpswqRqTbLAb4BcgAV34vv4aM= X-Received: by 2002:a5e:9309:: with SMTP id k9mr4608670iom.135.1594730166218; Tue, 14 Jul 2020 05:36:06 -0700 (PDT) MIME-Version: 1.0 References: <20200624203200.78870-1-samitolvanen@google.com> <671d8923-ed43-4600-2628-33ae7cb82ccb@molgen.mpg.de> <2ac9e722-949b-aa92-3553-df1bf69bf9e5@molgen.mpg.de> In-Reply-To: <2ac9e722-949b-aa92-3553-df1bf69bf9e5@molgen.mpg.de> Reply-To: sedat.dilek@gmail.com From: Sedat Dilek Date: Tue, 14 Jul 2020 14:35:52 +0200 Message-ID: Subject: Re: [PATCH 00/22] add support for Clang LTO To: Paul Menzel Cc: Sami Tolvanen , Masahiro Yamada , Will Deacon , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , Nick Desaulniers , Clang-Built-Linux ML , Kernel Hardening , linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild , LKML , linux-pci@vger.kernel.org, x86@kernel.org 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 Tue, Jul 14, 2020 at 2:16 PM Paul Menzel wrote: > > Dear Sami, > > > Am 13.07.20 um 01:34 schrieb Sami Tolvanen: > > 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. > > Thank you for clearing this up, and sorry for not checking myself. > > >> 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. > > Thank you for pointing me to the right direction. I am happy to report, > that with the diff below (no idea to what list to add the string), Linux > 5.8-rc5 with the LLVM/Clang/LTO patches on top, builds and boots on the > ASRock E350M1. > > ``` > diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c > index 8f3bf34840cef..e91af127ed3c0 100644 > --- a/arch/x86/tools/relocs.c > +++ b/arch/x86/tools/relocs.c > @@ -79,6 +79,7 @@ static const char * const > sym_regex_kernel[S_NSYMTYPES] = { > "__end_rodata_hpage_align|" > #endif > "__vvar_page|" > + "KERNEL_PAGES|" > "_end)$" > }; > ``` > What llvm-toolchain and version did you use? Can you post your linux-config? Thanks. - Sedat -