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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 6A0AAC43600 for ; Wed, 12 May 2021 15:27:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 385DC6142D for ; Wed, 12 May 2021 15:27:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235364AbhELP1j (ORCPT ); Wed, 12 May 2021 11:27:39 -0400 Received: from pegase2.c-s.fr ([93.17.235.10]:46309 "EHLO pegase2.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232285AbhELPNu (ORCPT ); Wed, 12 May 2021 11:13:50 -0400 Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4FgJF35p69z9sdw; Wed, 12 May 2021 17:12:39 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OuGIHfFU1rlH; Wed, 12 May 2021 17:12:39 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4FgJF34mzcz9sds; Wed, 12 May 2021 17:12:39 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 699D88B7F8; Wed, 12 May 2021 17:12:39 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id DmxO4iFZJL77; Wed, 12 May 2021 17:12:39 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 9F5F48B7F6; Wed, 12 May 2021 17:12:38 +0200 (CEST) Subject: Re: arch/powerpc/kernel/optprobes.c:34:1: error: unused function 'is_kprobe_ppc_optinsn_slot' To: Masami Hiramatsu Cc: Nathan Chancellor , kernel test robot , Nick Desaulniers , Masahiro Yamada , kbuild-all@lists.01.org, clang-built-linux@googlegroups.com, linux-kernel@vger.kernel.org, Michael Ellerman References: <202105120059.uTLH58Lm-lkp@intel.com> <48747467-cb93-c66d-4cf9-097be0568488@csgroup.eu> <208186f3-aab0-d94e-bcf4-8347983cc1a6@kernel.org> <0885f8b8-fea5-3fb0-42d7-b73e862a8c47@csgroup.eu> <520bd3e7-ddee-bbee-0735-6aad29acb5bb@csgroup.eu> <20210512215057.6875aeaf67fb31495ab29987@kernel.org> <20210513000649.23ac7bc69e30d8b9421a6ff6@kernel.org> From: Christophe Leroy Message-ID: <8d12be5a-d700-c0aa-86ee-ebb97927c34c@csgroup.eu> Date: Wed, 12 May 2021 17:12:32 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <20210513000649.23ac7bc69e30d8b9421a6ff6@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 12/05/2021 à 17:06, Masami Hiramatsu a écrit : > On Wed, 12 May 2021 21:50:57 +0900 > Masami Hiramatsu wrote: > >> On Wed, 12 May 2021 11:52:30 +0200 >> Christophe Leroy wrote: > >>> >>> Le 12/05/2021 à 11:36, Christophe Leroy a écrit : >>>> >>>> >>>> Le 11/05/2021 à 20:46, Nathan Chancellor a écrit : >>>>> On 5/11/2021 9:47 AM, Christophe Leroy wrote: >>>>>> Hi All, >>>>>> >>>>>> Le 11/05/2021 à 18:30, kernel test robot a écrit : >>>>>>> Hi Christophe, >>>>>>> >>>>>>> First bad commit (maybe != root cause): >>>>>>> >>>>>>> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master >>>>>>> head:   1140ab592e2ebf8153d2b322604031a8868ce7a5 >>>>>>> commit: eacf4c0202654adfa94bbb17b5c5c77c0be14af8 powerpc: Enable OPTPROBES on PPC32 >>>> >>>> Ok, the problem appears on PPC32 with that patch, but it must have been there on PPC64 since the >>>> implementation of optprobes with commit 51c9c0843993 ("powerpc/kprobes: Implement Optprobes") >>>> >>>> >>>>>>> date:   3 weeks ago >>>>>>> config: powerpc-randconfig-r033-20210511 (attached as .config) >>>>>>> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project >>>>>>> a0fed635fe1701470062495a6ffee1c608f3f1bc) >>>>>> >>>>>> A clang issue ? >>>>>> >>>>>> >>>>>>> reproduce (this is a W=1 build): >>>>>>>          wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O >>>>>>> ~/bin/make.cross >>>>>>>          chmod +x ~/bin/make.cross >>>>>>>          # install powerpc cross compiling tool for clang build >>>>>>>          # apt-get install binutils-powerpc-linux-gnu >>>>>>>          # >>>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eacf4c0202654adfa94bbb17b5c5c77c0be14af8 >>>>>>> >>>>>>>          git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git >>>>>>>          git fetch --no-tags linus master >>>>>>>          git checkout eacf4c0202654adfa94bbb17b5c5c77c0be14af8 >>>>>>>          # save the attached .config to linux build tree >>>>>>>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=powerpc >>>>>>> >>>>>>> If you fix the issue, kindly add following tag as appropriate >>>>>>> Reported-by: kernel test robot >>>>>>> >>>>>>> All errors (new ones prefixed by >>): >>>>>>> >>>>>>>>> arch/powerpc/kernel/optprobes.c:34:1: error: unused function 'is_kprobe_ppc_optinsn_slot' >>>>>>>>> [-Werror,-Wunused-function] >>>>>>>     DEFINE_INSN_CACHE_OPS(ppc_optinsn); >>>>>>>     ^ >>>>>>>     include/linux/kprobes.h:306:20: note: expanded from macro 'DEFINE_INSN_CACHE_OPS' >>>>>>>     static inline bool is_kprobe_##__name##_slot(unsigned long addr)        \ >>>>>> >>>>>> That's a 'static inline', shouldn't generate an 'unused function' warning. >>>>> This is a W=1 build, which means that "inline" does not silence unused function warnings with >>>>> clang because of commit 6863f5643dd7 ("kbuild: allow Clang to find unused static inline functions >>>>> for W=1 build"). >>>> >>>> Ok, I didn't know that. >>> >>> After looking at it in more details, I don't really know what should be done to avoid that. >> >> Ah, thanks for reporting! >> >>> >>> This unused function is defined as part of DEFINE_INSN_CACHE_OPS(ppc_optinsn). >>> >>> The code uses other items defined by macro DEFINE_INSN_CACHE_OPS, so it cannot be removed. >>> >>> Solution could be to hide that in a .h, but is that worth it ? >> >> The best solution is to remove ppc_optinsn, but that is defined in kernel/kprobes.c >> just because page allocation is different. >> I think the easiest fix is to add weak alloc_optinsn_page() and override it >> in arch/powerpc/kernel/optprobe.c. > > Please try this patch. > > Thank you, Yeah, look pretty similar to the two patches I sent 30 minutes ago. > > From 7782fa154349923ed52baa8843cc1d5eed26e82d Mon Sep 17 00:00:00 2001 > From: Masami Hiramatsu > Date: Wed, 12 May 2021 23:33:10 +0900 > Subject: [PATCH] powerpc/kprobes: Define arch specific optinsn memory > allocation > > @@ -203,14 +193,14 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p) > unsigned long nip, size; > int rc, i; > > - kprobe_ppc_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; > + kprobe_optinsn_slots.insn_size = MAX_OPTINSN_SIZE; Is this still needed ? It looks like it is already done by init_kprobes() in kernel/kprobes.c > > nip = can_optimize(p); > if (!nip) > return -EILSEQ; > > /* Allocate instruction slot for detour buffer */ > - buff = get_ppc_optinsn_slot(); > + buff = get_optinsn_slot(); > if (!buff) > return -ENOMEM; > Christophe