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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D40E9C352B6 for ; Mon, 9 May 2022 01:29:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235717AbiEIBb7 (ORCPT ); Sun, 8 May 2022 21:31:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234444AbiEIALS (ORCPT ); Sun, 8 May 2022 20:11:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD1565594 for ; Sun, 8 May 2022 17:07:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 55C9160F13 for ; Mon, 9 May 2022 00:07:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3F74CC385AC; Mon, 9 May 2022 00:07:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652054844; bh=bHmScepPN7hiopWGp4Kksweb2MJZ9UmfSD6aznw0bIQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QWziOI/mxznBq6oexsLOCR4AhVWh+JvIbO7TsfylwMPxv6ZNycNSqGW8E5XfuvAB3 8mjOvyNDBEPnA52h1dSX1sJWZfsNugYJomO+bov+1M5CSsPlug8KU5cyUAo4DPPupM D47fkVLkscKkMJk5ZOgKKLPX0xOoheg/wPo0WM6u917gHYtizntQsyTa3ESY3aA7ES XELPW3DvXI3Y+Id/EdxhJZSdfU9kJMoIGad69ni47JHQ3phPwDyspF8FSr3LEBK3fY 7R1H7YhcwtFg6VvxenzWvQKavKDz+vj2xSuHnosmirIBhxYE6MYjaCT0j8Ee8mtUGY nnaHkrTI7lHjQ== Date: Sun, 8 May 2022 17:07:22 -0700 From: Nathan Chancellor To: Mauro Rossi Cc: luto@kernel.org, Chih-Wei Huang , Linux Kernel Mailing List , clang-built-linux , Nick Desaulniers Subject: Re: arch/x86/entry/entry: RFC on recent kernels building error with llvm 11.0.2 internal assembler Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 07, 2022 at 02:19:00PM +0200, Mauro Rossi wrote: > > > Alternatively, you could apply the hack that Nick inserted into Android > > > for this issue if upgrading your toolchain or turning off the integrated > > > assembler is not possible: > > > > > > https://android.googlesource.com/kernel/common/+/e58f084735b8abf744d61083b92172ee23d45aae > > > > > > I really do not mean to sound dismissive or rude, I apologize if it > > > comes off that way, but we have worked quite hard to avoid inserting > > > unnecessary workarounds, as they are ultimately technical debt that can > > > be hard to manage over the long term. > > > > > > Cheers, > > > Nathan > > > > Thanks a lot Nathan > > > > It is definitely the clang version 11.0.x which is not updated in aosp > > Android 11 production tags > > > > I will use Nick's workaround which works since only lsl %rax, %rax is > > currently happening > > > > Many thanks, problem solved > > Hello, > I'm back again because I was assuming that Nick's workaround was working ok, > but I have found that ARCH=x86_64 i.e. 64bit built kernel is causing > an immediate hard reboot at initrd execution, > just after hitting [ENTER] at grub/efi menu. It looks like there was a follow up fix for that workaround, maybe that resolves this issue as well? https://android.googlesource.com/kernel/common/+/cc7f7a84191f5defc2ea4633eeea4acb4486b549 > ARCh=x86 i.e. 32bit kernel binary is not affected, but is Nick's > workaround targeting 32 bit kernel builds? No, the file that the build error originates from (entry_64.S) is only built on x86_64. > How do aosp android-mailine kernels avoid this instantaneous hard reboot issue? That hack was reverted once the toolchain was upgraded: https://android.googlesource.com/kernel/common/+/ff0216d09fd31802537f2d1702ec2f3e9be73aa3 https://android.googlesource.com/kernel/common/+/3c2c8d8f7f2639e319212d10cb8df5bd13098dae Cheers, Nathan