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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 87CD4C48BD4 for ; Tue, 25 Jun 2019 14:11:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6381A208E3 for ; Tue, 25 Jun 2019 14:11:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729885AbfFYOLZ (ORCPT ); Tue, 25 Jun 2019 10:11:25 -0400 Received: from foss.arm.com ([217.140.110.172]:42712 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728130AbfFYOLY (ORCPT ); Tue, 25 Jun 2019 10:11:24 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1B73F2B; Tue, 25 Jun 2019 07:11:24 -0700 (PDT) Received: from [10.1.196.72] (e119884-lin.cambridge.arm.com [10.1.196.72]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DD24D3F718; Tue, 25 Jun 2019 07:11:22 -0700 (PDT) Subject: Re: "arm64: vdso: Substitute gettimeofday() with C implementation" breaks clang build To: Qian Cai Cc: Thomas Gleixner , Will Deacon , Catalin Marinas , linux-arm-kernel@lists.infradead.org, "linux-kernel@vger.kernel.org" , natechancellor@gmail.com, ndesaulniers@google.com References: <1561464964.5154.63.camel@lca.pw> <1561467369.5154.67.camel@lca.pw> <00a78980-6b9c-5d5b-ed01-b28bb34be022@arm.com> <1561470705.5154.68.camel@lca.pw> From: Vincenzo Frascino Message-ID: <5113362e-1256-6712-6ce8-9599b1806cf1@arm.com> Date: Tue, 25 Jun 2019 15:11:21 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <1561470705.5154.68.camel@lca.pw> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Qian, On 25/06/2019 14:51, Qian Cai wrote: > On Tue, 2019-06-25 at 14:40 +0100, Vincenzo Frascino wrote: >> On 25/06/2019 13:56, Qian Cai wrote: >>> On Tue, 2019-06-25 at 13:47 +0100, Vincenzo Frascino wrote: >>>> Hi Qian, >>>> >>>> On 25/06/2019 13:16, Qian Cai wrote: >>>>> The linux-next commit "arm64: vdso: Substitute gettimeofday() with C >>>>> implementation" [1] breaks clang build. >>>>> >>>>> error: invalid value 'tiny' in '-mcode-model tiny' >>>>> make[1]: *** [scripts/Makefile.build:279: >>>>> arch/arm64/kernel/vdso/vgettimeofday.o] Error 1 >>>>> make[1]: *** Waiting for unfinished jobs.... >>>>> make: *** [arch/arm64/Makefile:180: vdso_prepare] Error 2 >>>>> >>>>> [1] https://patchwork.kernel.org/patch/11009663/ >>>>> >>>> >>>> I am not sure what does exactly break from your report. Could you please >>>> provide >>>> more details? >>> >>> Here is the config to reproduce. >>> >>> https://raw.githubusercontent.com/cailca/linux-mm/master/arm64.config >>> >>> # make CC=clang -j $(nr_cpus) >>> >>> I can get it working again by removing "-mcmodel=tiny" in >>> arch/arm64/kernel/vdso/Makefile >>> >> >> With your defconfig I can't still reproduce the problem. Which version of >> clang >> are you using? > > Compiler: clang version 7.0.1 (tags/RELEASE_701/final) > I am using clang 8.0.0. Could you please try with it and see if the issue goes away? Thanks, Vincenzo >> >>>> >>>> On my env: >>>> >>>> $ make mrproper && make defconfig && make CC=clang HOSTCC=clang -j$(nproc) >>>> >>>> ... >>>> >>>> arch/arm64/Makefile:56: CROSS_COMPILE_COMPAT is clang, the compat vDSO >>>> will >>>> not >>>> be built >>>> >>>> ... >>>> >>>>   LDS     arch/arm64/kernel/vdso/vdso.lds >>>>   AS      arch/arm64/kernel/vdso/note.o >>>>   AS      arch/arm64/kernel/vdso/sigreturn.o >>>>   CC      arch/arm64/kernel/vdso/vgettimeofday.o >>>>   LD      arch/arm64/kernel/vdso/vdso.so.dbg >>>>   VDSOCHK arch/arm64/kernel/vdso/vdso.so.dbg >>>>   VDSOSYM include/generated/vdso-offsets.h >>>> >>>> ... >>>> >>>>   LD      vmlinux.o >>>>   MODPOST vmlinux.o >>>>   MODINFO modules.builtin.modinfo >>>>   KSYM    .tmp_kallsyms1.o >>>>   KSYM    .tmp_kallsyms2.o >>>>   LD      vmlinux >>>>   SORTEX  vmlinux >>>>   SYSMAP  System.map >>>>   Building modules, stage 2. >>>>   OBJCOPY arch/arm64/boot/Image >>>>   MODPOST 483 modules >>>> >> >> -- Regards, Vincenzo