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,URIBL_BLOCKED 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 33C0BC48BD5 for ; Tue, 25 Jun 2019 13:40:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 12A06213F2 for ; Tue, 25 Jun 2019 13:40:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730057AbfFYNkl (ORCPT ); Tue, 25 Jun 2019 09:40:41 -0400 Received: from foss.arm.com ([217.140.110.172]:42212 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727138AbfFYNkk (ORCPT ); Tue, 25 Jun 2019 09:40:40 -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 8C4A72B; Tue, 25 Jun 2019 06:40:40 -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 87F233F718; Tue, 25 Jun 2019 06:40:39 -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> From: Vincenzo Frascino Message-ID: <00a78980-6b9c-5d5b-ed01-b28bb34be022@arm.com> Date: Tue, 25 Jun 2019 14:40:38 +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: <1561467369.5154.67.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 Qin, 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? >> >> 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