From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============9212793012446649767==" MIME-Version: 1.0 From: Masami Hiramatsu To: kbuild-all@lists.01.org Subject: Re: arch/powerpc/kernel/optprobes.c:34:1: error: unused function 'is_kprobe_ppc_optinsn_slot' Date: Thu, 13 May 2021 08:42:39 +0900 Message-ID: <20210513084239.3af8c2498263e7f0b233b72e@kernel.org> In-Reply-To: <8d12be5a-d700-c0aa-86ee-ebb97927c34c@csgroup.eu> List-Id: --===============9212793012446649767== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable On Wed, 12 May 2021 17:12:32 +0200 Christophe Leroy wrote: > = > = > Le 12/05/2021 =C3=A0 17:06, Masami Hiramatsu a =C3=A9crit=C2=A0: > > 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 =C3=A0 11:36, Christophe Leroy a =C3=A9crit=C2=A0: > >>>> > >>>> > >>>> Le 11/05/2021 =C3=A0 20:46, Nathan Chancellor a =C3=A9crit=C2=A0: > >>>>> On 5/11/2021 9:47 AM, Christophe Leroy wrote: > >>>>>> Hi All, > >>>>>> > >>>>>> Le 11/05/2021 =C3=A0 18:30, kernel test robot a =C3=A9crit=C2=A0: > >>>>>>> Hi Christophe, > >>>>>>> > >>>>>>> First bad commit (maybe !=3D root cause): > >>>>>>> > >>>>>>> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/li= nux.git master > >>>>>>> head:=C2=A0=C2=A0 1140ab592e2ebf8153d2b322604031a8868ce7a5 > >>>>>>> commit: eacf4c0202654adfa94bbb17b5c5c77c0be14af8 powerpc: Enable = OPTPROBES on PPC32 > >>>> > >>>> Ok, the problem appears on PPC32 with that patch, but it must have b= een there on PPC64 since the > >>>> implementation of optprobes with commit 51c9c0843993 ("powerpc/kprob= es: Implement Optprobes") > >>>> > >>>> > >>>>>>> date:=C2=A0=C2=A0 3 weeks ago > >>>>>>> config: powerpc-randconfig-r033-20210511 (attached as .config) > >>>>>>> compiler: clang version 13.0.0 (https://github.com/llvm/llvm-proj= ect > >>>>>>> a0fed635fe1701470062495a6ffee1c608f3f1bc) > >>>>>> > >>>>>> A clang issue ? > >>>>>> > >>>>>> > >>>>>>> reproduce (this is a W=3D1 build): > >>>>>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 wget https://ra= w.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O > >>>>>>> ~/bin/make.cross > >>>>>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 chmod +x ~/bin/= make.cross > >>>>>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 # install power= pc cross compiling tool for clang build > >>>>>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 # apt-get insta= ll binutils-powerpc-linux-gnu > >>>>>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 # > >>>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.gi= t/commit/?id=3Deacf4c0202654adfa94bbb17b5c5c77c0be14af8 > >>>>>>> > >>>>>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 git remote add = linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > >>>>>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 git fetch --no-= tags linus master > >>>>>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 git checkout ea= cf4c0202654adfa94bbb17b5c5c77c0be14af8 > >>>>>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 # save the atta= ched .config to linux build tree > >>>>>>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 COMPILER_INSTAL= L_PATH=3D$HOME/0day COMPILER=3Dclang make.cross W=3D1 ARCH=3Dpowerpc > >>>>>>> > >>>>>>> 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 'i= s_kprobe_ppc_optinsn_slot' > >>>>>>>>> [-Werror,-Wunused-function] > >>>>>>> =C2=A0=C2=A0=C2=A0 DEFINE_INSN_CACHE_OPS(ppc_optinsn); > >>>>>>> =C2=A0=C2=A0=C2=A0 ^ > >>>>>>> =C2=A0=C2=A0=C2=A0 include/linux/kprobes.h:306:20: note: expande= d from macro 'DEFINE_INSN_CACHE_OPS' > >>>>>>> =C2=A0=C2=A0=C2=A0 static inline bool is_kprobe_##__name##_slot(= unsigned long addr)=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 \ > >>>>>> > >>>>>> That's a 'static inline', shouldn't generate an 'unused function' = warning. > >>>>> This is a W=3D1 build, which means that "inline" does not silence u= nused function warnings with > >>>>> clang because of commit 6863f5643dd7 ("kbuild: allow Clang to find = unused static inline functions > >>>>> for W=3D1 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 ker= nel/kprobes.c > >> just because page allocation is different. > >> I think the easiest fix is to add weak alloc_optinsn_page() and overri= de 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. Ah, I missed it. OK, let me check. > = > = > = > > = > > 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 optimize= d_kprobe *op, struct kprobe *p) > > unsigned long nip, size; > > int rc, i; > > = > > - kprobe_ppc_optinsn_slots.insn_size =3D MAX_OPTINSN_SIZE; > > + kprobe_optinsn_slots.insn_size =3D MAX_OPTINSN_SIZE; > = > Is this still needed ? It looks like it is already done by init_kprobes()= in kernel/kprobes.c No, not needed anymore. Thanks! > = > > = > > nip =3D can_optimize(p); > > if (!nip) > > return -EILSEQ; > > = > > /* Allocate instruction slot for detour buffer */ > > - buff =3D get_ppc_optinsn_slot(); > > + buff =3D get_optinsn_slot(); > > if (!buff) > > return -ENOMEM; > > = > = > Christophe -- = Masami Hiramatsu --===============9212793012446649767==-- 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=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,NICE_REPLY_A,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 AD692C433ED for ; Wed, 12 May 2021 23:45:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7EC4461411 for ; Wed, 12 May 2021 23:45:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237799AbhELXpv (ORCPT ); Wed, 12 May 2021 19:45:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:55788 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242436AbhELXnw (ORCPT ); Wed, 12 May 2021 19:43:52 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1CF4361405; Wed, 12 May 2021 23:42:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620862963; bh=bBPSkdJClvqx7hJbv2Uw+r6yTupo3DEBhnSqx77Z9G0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=k6cWidD1WqlrCWf3BPzMKbY9Da1paqsrfqW0ThwCybJFtN7GSys0CNK/rOnPchazW W6L9ys4B2N1XmMQ5xk9wK/mVBtxiunERZWkcOFX1uraaA02imNBV9Bi/5fFyl9nXTv OypVTvGv5BKnGPc/uQVshTzH/qSVnYmJfundS5eLDePsjQ+A5QhAHeyu8N7gUwNTQQ 9uTDsQzstzrr1b6Kl+y9r3SvjtNaCppB7T4dPEHF+pz8BI9ML86mHwDkAAsQ/DcpjD ZWIkI7upMu7JvWMH8pamr4BB1+c0ncC10LoI7tz//g+HkJStA8x7i1L7VI67Rg/FiV iLX/txjDzeCgQ== Date: Thu, 13 May 2021 08:42:39 +0900 From: Masami Hiramatsu To: Christophe Leroy 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 Subject: Re: arch/powerpc/kernel/optprobes.c:34:1: error: unused function 'is_kprobe_ppc_optinsn_slot' Message-Id: <20210513084239.3af8c2498263e7f0b233b72e@kernel.org> In-Reply-To: <8d12be5a-d700-c0aa-86ee-ebb97927c34c@csgroup.eu> 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> <8d12be5a-d700-c0aa-86ee-ebb97927c34c@csgroup.eu> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 12 May 2021 17:12:32 +0200 Christophe Leroy wrote: > > > 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. Ah, I missed it. OK, let me check. > > > > > > > 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 No, not needed anymore. Thanks! > > > > > 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 -- Masami Hiramatsu