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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05998C433EF for ; Sun, 22 May 2022 16:11:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347547AbiEVQLP (ORCPT ); Sun, 22 May 2022 12:11:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236815AbiEVQK4 (ORCPT ); Sun, 22 May 2022 12:10:56 -0400 Received: from conssluserg-05.nifty.com (conssluserg-05.nifty.com [210.131.2.90]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E05EE313; Sun, 22 May 2022 09:10:53 -0700 (PDT) Received: from mail-pf1-f181.google.com (mail-pf1-f181.google.com [209.85.210.181]) (authenticated) by conssluserg-05.nifty.com with ESMTP id 24MGAUYi016368; Mon, 23 May 2022 01:10:31 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-05.nifty.com 24MGAUYi016368 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1653235831; bh=DEp5fBCqcC+u4Tiia8L97bV7x6IbnuPyZilUMmH5ipc=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=Z03QEWvNuPhA6Gude4TH8T2FMkpAN2BYSuJACXRd5Tg8xdNUw1+vNWgeFy9H9ZupE 6nGG2bISvxlHkDhbkrB//TN06xVPvN7kvxHs+Jegmkrd+kBnpdfhcxy+2p36xOypx5 fNb5oAVvPxfdHaAkeWemllSbnqfT9EC2AogChntF9wecVJ/3vAP+tFo/L9w9t10Te8 5rdNhw3AXjyfTwxOn1zQVZjZhu4O2W6vZsbRVD8lC06+ESSUqn+fLduYBXzsDnNYr1 5/QSoG/15dKJJhj2Db/GvTKC1I8JsyFQMDeu03D2HLfuN08KevhCRb2oTjzC8plBqQ eAh2KdXLXI/EQ== X-Nifty-SrcIP: [209.85.210.181] Received: by mail-pf1-f181.google.com with SMTP id x143so11685436pfc.11; Sun, 22 May 2022 09:10:31 -0700 (PDT) X-Gm-Message-State: AOAM530bb3VmVb0YckZZp3XQiQVY/xecqpZhzrAXniFAnA58xUVJPFDz PtmMx0cu3oeVOxVIzGWrIyM1kNS4yeVZu5fsFfg= X-Google-Smtp-Source: ABdhPJyL484cEbf9xdiYoTqXVAC6TVupXkdrNLtgZyNBC4T6SsOQ10FGXBLVsElMxcuaSv87Z2P669yaDqF4iCWfgj0= X-Received: by 2002:a63:9043:0:b0:3f9:6c36:3de3 with SMTP id a64-20020a639043000000b003f96c363de3mr9611252pge.616.1653235830234; Sun, 22 May 2022 09:10:30 -0700 (PDT) MIME-Version: 1.0 References: <20220513113930.10488-1-masahiroy@kernel.org> In-Reply-To: From: Masahiro Yamada Date: Mon, 23 May 2022 01:09:11 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v6 00/10] kbuild: yet another series of cleanups (modpost, LTO, MODULE_REL_CRCS, export.h) To: Sedat Dilek Cc: Linux Kbuild mailing list , Linux Kernel Mailing List , Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Peter Zijlstra , linux-modules , clang-built-linux , Ard Biesheuvel , Sami Tolvanen Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 22, 2022 at 11:16 PM Sedat Dilek wrote: > > On Sun, May 22, 2022 at 11:45 AM Sedat Dilek wrote: > > > > On Sun, May 22, 2022 at 8:50 AM Masahiro Yamada wrote: > > > > > > On Sun, May 22, 2022 at 10:45 AM Sedat Dilek wrote: > > > > > > > > On Fri, May 13, 2022 at 4:31 PM Masahiro Yamada wrote: > > > > > > > > > > On Fri, May 13, 2022 at 8:42 PM Masahiro Yamada wrote: > > > > > > > > > > > > > > > > > > This is the third batch of cleanups in this development cycle. > > > > > > > > > > > > > > > > > > > > > This series is available at > > > > > git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git > > > > > lto-cleanup-v6 > > > > > > > > > > > > > Hi Masahiro, > > > > > > > > I cloned the repository on top of latest Linus Git. > > > > > > > > Not able to boot in Quemu - Not able to boot on bare metal. > > > > > > > > $ grep module_layout log_quemu-5.18.0-rc7-2-amd64-clang14-lto.txt > > > > 366:[ 2.173265] floppy: disagrees about version of symbol module_layout > > > > 367:[ 2.198746] scsi_common: disagrees about version of symbol module_layout > > > > 368:[ 2.205573] i2c_piix4: disagrees about version of symbol module_layout > > > > 369:[ 2.210610] psmouse: disagrees about version of symbol module_layout > > > > 370:[ 2.225138] scsi_common: disagrees about version of symbol module_layout > > > > 371:[ 2.235536] scsi_common: disagrees about version of symbol module_layout > > > > 375:Begin: Running /scripts/local-premount ... [ 2.298555] > > > > crc32c_intel: disagrees about version of symbol module_layout > > > > 376:[ 2.303335] crc32c_generic: disagrees about version of symbol > > > > module_layout > > > > 377:[ 2.306667] libcrc32c: disagrees about version of symbol module_layout > > > > > > > > Infos: LLVM-14 + CONFIG_LTO_CLANG_THIN=y > > > > > > > > My linux-config and qemu-log are attached. > > > > > > > > > > > > > Thanks for your testing. > > > > > > I was also able to reproduce this issue. > > > > > > > > > The problematic parts are: > > > > > > [ 2.298555] crc32c_intel: disagrees about version of symbol module_layout > > > [ 2.303335] crc32c_generic: disagrees about version of symbol module_layout > > > [ 2.306667] libcrc32c: disagrees about version of symbol module_layout > > > > > > > > > > > > When CONFIG_LTO_CLANG_THIN=y, > > > I cannot see any __crc_* symbols in "nm vmlinux". > > > > > > Perhaps, LTO might have discarded all the __crc_* symbols > > > from vmlinux, but I am still checking the details... > > > > > > > Thanks for taking care. > > > > Just for the records: > > > > $ grep CONFIG_MODVERSIONS /boot/config-5.18.0-rc7-2-amd64-clang14-lto > > CONFIG_MODVERSIONS=y > > > > Did not try CONFIG_MODVERSIONS=n. > > We have a new file: > > [ include/linux/export-internal.h ] > /* SPDX-License-Identifier: GPL-2.0-only */ > /* > * Please do not include this explicitly. > * This is used by C files generated by modpost. > */ > > #ifndef __LINUX_EXPORT_INTERNAL_H__ > #define __LINUX_EXPORT_INTERNAL_H__ > > #include > #include > > #define SYMBOL_CRC(sym, crc, sec) \ > u32 __section("___kcrctab" sec "+" #sym) __crc_##sym = crc > > #endif /* __LINUX_EXPORT_INTERNAL_H__ */ > > But we discard __kcrctab in scripts/module.lds.S file. No. scripts/module.lds.S keeps __kcrctab. The discarded sections are specified a few lines above: /DISCARD/ : { *(.discard) *(.discard.*) SANITIZER_DISCARDS } > Maybe we need: No. The problem is __crc_* symbols are dropped from vmlinux when CONFIG_LTO_CLANG=y. Please try this fixup: https://lore.kernel.org/linux-kbuild/20220522160117.599023-1-masahiroy@kernel.org/T/#u > > $ git diff scripts/module.lds.S > diff --git a/scripts/module.lds.S b/scripts/module.lds.S > index 1d0e1e4dc3d2..c04b596c364b 100644 > --- a/scripts/module.lds.S > +++ b/scripts/module.lds.S > @@ -21,8 +21,6 @@ SECTIONS { > > __ksymtab 0 : { *(SORT(___ksymtab+*)) } > __ksymtab_gpl 0 : { *(SORT(___ksymtab_gpl+*)) } > - __kcrctab 0 : { *(SORT(___kcrctab+*)) } > - __kcrctab_gpl 0 : { *(SORT(___kcrctab_gpl+*)) } > > .ctors 0 : ALIGN(8) { *(SORT(.ctors.*)) *(.ctors) } > .init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) > *(.init_array) } > > Or even? > > $ git diff scripts/kallsyms.c > diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c > index 8caabddf817c..fb3601fe8aa3 100644 > --- a/scripts/kallsyms.c > +++ b/scripts/kallsyms.c > @@ -109,7 +109,6 @@ static bool is_ignored_symbol(const char *name, char type) > static const char * const ignored_prefixes[] = { > "$", /* local symbols for ARM, MIPS, etc. */ > ".L", /* local labels, > .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc. */ > - "__crc_", /* modversions */ > "__efistub_", /* arm64 EFI stub namespace */ > "__kvm_nvhe_", /* arm64 non-VHE KVM namespace */ > "__AArch64ADRPThunk_", /* arm64 lld */ > > - Sedat - -- Best Regards Masahiro Yamada