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=-14.6 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, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 1AAF6C388F9 for ; Thu, 5 Nov 2020 06:58:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB5EA20786 for ; Thu, 5 Nov 2020 06:58:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qU8KRHAW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727018AbgKEG6s (ORCPT ); Thu, 5 Nov 2020 01:58:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725287AbgKEG6s (ORCPT ); Thu, 5 Nov 2020 01:58:48 -0500 Received: from mail-io1-xd42.google.com (mail-io1-xd42.google.com [IPv6:2607:f8b0:4864:20::d42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23215C0613CF; Wed, 4 Nov 2020 22:58:48 -0800 (PST) Received: by mail-io1-xd42.google.com with SMTP id u19so758046ion.3; Wed, 04 Nov 2020 22:58:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=xgK5C/kmHCdYMo/R51mOn46TRz+P9lQZN5x72FBClZg=; b=qU8KRHAWTdGzsF4J6Ys7Tkj08FpemaSAAMbCgNpt5J8Kk8GMVGg76D6IuyudobkT0A YRQ2xjCPHxFr2drMUqmnf58Rz7bGVZqElO+2JrJTclL0F35iqzn0bnlPIFH2md3bYgre L7mTQ49VriewSJLeluMG20EweK80i4oGywhchKA2YuF39yKBg6Gdhw1sz/t+NyHwn2Zr yuZeLjekvBtSAYtaaQWHt3Dv7POzD4Z7oGixqo/p/9fqG3pyrJGdFusuRk5z0eEYaFdW n/JmT6qGzEmRsOYjmsuY/2e8UaTVft3qLPWU5QB0sj+JHD1p8YcIT6f08Cm/SAN/Ka7H qhVA== 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=xgK5C/kmHCdYMo/R51mOn46TRz+P9lQZN5x72FBClZg=; b=dWbbHhoxC34CgjtrDEVqijLMfKTtw4sydjerFI/gh5YD6OkoXYdYOvsUJQQqQIp0kY /ejmyXpjqYyUqMfhv2g5mTVoBlH31nkjudnZJDkTg3zCuzVihQcvca4zC7w2MGK7lRLm OmUktc/4ulrFfJphKp2phcR5QFV9l00BRXYJHFrmS+DMpx3HiELy6UWBjST0gcDYG6Ys KLm4Do0n8cq2z8ccZX7Zwdp8zX0Cd78cSaMtHFf0sJnq8jVId0j3FBoOKopY7xDZjaVq dJStBOkAZQfnPbKh5B6erQy7dhmEH5Fd2xuJpvDdhEBBAwwjTf7rx5XXpB6DMC1JyIp0 wCyQ== X-Gm-Message-State: AOAM532Q1LVheZTXLa6g04JoT7dZSjs4O/8vnVsN3NLuoGIIb1cHLEdg uICexS3HnCId+pdxJiK5ack= X-Google-Smtp-Source: ABdhPJzFmZM1hex1Mo0bDhYe1yj7LOV2SnmMToXn3dPj+RK5ZWGd5alBm12txPxzgJYNE4mOwE3uXg== X-Received: by 2002:a02:3842:: with SMTP id v2mr981798jae.50.1604559527215; Wed, 04 Nov 2020 22:58:47 -0800 (PST) Received: from ubuntu-m3-large-x86 ([2604:1380:45f1:1d00::1]) by smtp.gmail.com with ESMTPSA id i3sm520813iom.8.2020.11.04.22.58.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Nov 2020 22:58:46 -0800 (PST) Date: Wed, 4 Nov 2020 23:58:44 -0700 From: Nathan Chancellor To: Nick Desaulniers Cc: Masahiro Yamada , Jakub Jelinek , Linux Kbuild mailing list , Linux Kernel Mailing List , linux-toolchains@vger.kernel.org, clang-built-linux , Fangrui Song , Sedat Dilek , Dmitry Golovin , Alistair Delva , stable@vger.kernel.org Subject: Re: [PATCH v2 2/4] Kbuild: do not emit debug info for assembly with LLVM_IAS=1 Message-ID: <20201105065844.GA3243074@ubuntu-m3-large-x86> References: <20201104005343.4192504-1-ndesaulniers@google.com> <20201104005343.4192504-3-ndesaulniers@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201104005343.4192504-3-ndesaulniers@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 03, 2020 at 04:53:41PM -0800, Nick Desaulniers wrote: > Clang's integrated assembler produces the warning for assembly files: > > warning: DWARF2 only supports one section per compilation unit > > If -Wa,-gdwarf-* is unspecified, then debug info is not emitted. This Is this something that should be called out somewhere? If I understand this correctly, LLVM_IAS=1 + CONFIG_DEBUG_INFO=y won't work? Maybe this should be handled in Kconfig? > will be re-enabled for new DWARF versions in a follow up patch. > > Enables defconfig+CONFIG_DEBUG_INFO to build cleanly with > LLVM=1 LLVM_IAS=1 for x86_64 and arm64. > > Cc: > Link: https://github.com/ClangBuiltLinux/linux/issues/716 > Reported-by: Nathan Chancellor > Suggested-by: Dmitry Golovin If you happen to respin, Dmitry deserves a Reported-by tag too :) > Suggested-by: Sedat Dilek > Signed-off-by: Nick Desaulniers Regardless of the other two comments, this is fine as is as a fix for stable to unblock Android + CrOS since we have been running something similar to it in CI: Reviewed-by: Nathan Chancellor > --- > Makefile | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/Makefile b/Makefile > index f353886dbf44..75b1a3dcbf30 100644 > --- a/Makefile > +++ b/Makefile > @@ -826,7 +826,9 @@ else > DEBUG_CFLAGS += -g > endif > > +ifndef LLVM_IAS Nit: this should probably match the existing LLVM_IAS check ifneq ($(LLVM_IAS),1) > KBUILD_AFLAGS += -Wa,-gdwarf-2 > +endif > > ifdef CONFIG_DEBUG_INFO_DWARF4 > DEBUG_CFLAGS += -gdwarf-4 > -- > 2.29.1.341.ge80a0c044ae-goog >