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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 8A443C10DCE for ; Sat, 14 Mar 2020 02:12:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 42F43206E7 for ; Sat, 14 Mar 2020 02:12:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584151955; bh=2kZ/Ix9VtKRzt7pySpx+QAFvVZ9F4ASqSH8H+xICraU=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=UyIbDQVBF2JnBA+GylUoU00SWOkzTNSAY1wJIuRBKP7zxAybgDU6OnwFhm0FcKGIZ oStJEuTsCubMCFu/C9vCA12aAILbITW1oMLoNgJaTi6X5vsmfQTFFYPLBFOcTl0t15 AzekymK1CbJL7si0G8F2/4zFkOVQs92gGUeZyaQk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726646AbgCNCMe (ORCPT ); Fri, 13 Mar 2020 22:12:34 -0400 Received: from conssluserg-01.nifty.com ([210.131.2.80]:60521 "EHLO conssluserg-01.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726414AbgCNCMd (ORCPT ); Fri, 13 Mar 2020 22:12:33 -0400 Received: from mail-vs1-f54.google.com (mail-vs1-f54.google.com [209.85.217.54]) (authenticated) by conssluserg-01.nifty.com with ESMTP id 02E2CP2u023350; Sat, 14 Mar 2020 11:12:25 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-01.nifty.com 02E2CP2u023350 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1584151946; bh=GhT3aXuBvPthoFeT4yZR0mqs1IRA+1JuQlU0tGqcrJU=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=kYQwFuACp+DPevM5oQFXs9Ib6OTUSSam0ZTV7rTNcw9h2UmGRpoXSQWJzzWmAFFWa /pKr6xsxkhTPXiIpsUAuCSTinXh1eFbsrDVXJT2HlY6oRQsBX1GL7vxRZQ2k3uptTY xbz2DLLnIzlc6iTZ9HnYEOVEGpUSaoCnUOXjhaUio3XxRgw9SXeY2jvovk7mOryfj/ 465yfohXBjEKhe6wX4e6IJaigie0xm5M3R0wEgA1XQm1HcafG3Y8LKxL6UKe+Eit3O yi8NExOc8SP+qWN5JLR2N/Uo8eHIwDCH9uwHkNiwofQmfJMti2SdP22h3qS4WZCRoF 82LamnoRKB2/g== X-Nifty-SrcIP: [209.85.217.54] Received: by mail-vs1-f54.google.com with SMTP id n27so7675171vsa.0; Fri, 13 Mar 2020 19:12:25 -0700 (PDT) X-Gm-Message-State: ANhLgQ3fr3P+CshaprNTEKBMu5e0HpzULM49LC2t4fF4GYwr5xBkO4+c ROb/hwWcZOH0fP39QrzB+9bPtHzLk+hARt/zHsc= X-Google-Smtp-Source: ADFU+vtaZyYpm3dCRe0vFXfXoe7d1/Tma6ScVCnWx2otGG1rDf5iFDKV1/k6kjd53me7l49arctAbI5aKKSU9W6+5+Q= X-Received: by 2002:a67:eb91:: with SMTP id e17mr6970094vso.179.1584151944414; Fri, 13 Mar 2020 19:12:24 -0700 (PDT) MIME-Version: 1.0 References: <20200311170120.12641-1-jeyu@kernel.org> In-Reply-To: <20200311170120.12641-1-jeyu@kernel.org> From: Masahiro Yamada Date: Sat, 14 Mar 2020 11:11:48 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2] modpost: move the namespace field in Module.symvers last To: Jessica Yu Cc: Matthias Maennich , Lucas De Marchi , stable , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 12, 2020 at 2:02 AM Jessica Yu wrote: > > In order to preserve backwards compatability with kmod tools, we have to > move the namespace field in Module.symvers last, as the depmod -e -E > option looks at the first three fields in Module.symvers to check symbol > versions (and it's expected they stay in the original order of crc, > symbol, module). > > In addition, update an ancient comment above read_dump() in modpost that > suggested that the export type field in Module.symvers was optional. I > suspect that there were historical reasons behind that comment that are > no longer accurate. We have been unconditionally printing the export > type since 2.6.18 (commit bd5cbcedf44), which is over a decade ago now. > > Fix up read_dump() to treat each field as non-optional. I suspect the > original read_dump() code treated the export field as optional in order > to support pre <= 2.6.18 Module.symvers (which did not have the export > type field). Note that although symbol namespaces are optional, the > field will not be omitted from Module.symvers if a symbol does not have > a namespace. In this case, the field will simply be empty and the next > delimiter or end of line will follow. > > Cc: stable@vger.kernel.org > Fixes: cb9b55d21fe0 ("modpost: add support for symbol namespaces") > Tested-by: Matthias Maennich > Reviewed-by: Matthias Maennich > Reviewed-by: Lucas De Marchi > Signed-off-by: Jessica Yu While I am not opposed to this fix, I did not even notice Module.symvers was official interface. Kbuild invokes scripts/depmod.sh to finalize the 'make modules_install', but I do not see the -E option being used there. I do not see Module.symvers installed in /lib/modules/$(uname -r)/. > --- > v2: > > - Explain the changes to read_dump() and the comment (and provide > historical context) in the commit message. (Lucas De Marchi) > > Documentation/kbuild/modules.rst | 4 ++-- > scripts/export_report.pl | 2 +- > scripts/mod/modpost.c | 24 ++++++++++++------------ > 3 files changed, 15 insertions(+), 15 deletions(-) > > diff --git a/Documentation/kbuild/modules.rst b/Documentation/kbuild/modules.rst > index 69fa48ee93d6..e0b45a257f21 100644 > --- a/Documentation/kbuild/modules.rst > +++ b/Documentation/kbuild/modules.rst > @@ -470,9 +470,9 @@ build. > > The syntax of the Module.symvers file is:: > > - > + > > - 0xe1cc2a05 usb_stor_suspend USB_STORAGE drivers/usb/storage/usb-storage EXPORT_SYMBOL_GPL > + 0xe1cc2a05 usb_stor_suspend drivers/usb/storage/usb-storage EXPORT_SYMBOL_GPL USB_STORAGE > > The fields are separated by tabs and values may be empty (e.g. > if no namespace is defined for an exported symbol). > diff --git a/scripts/export_report.pl b/scripts/export_report.pl > index 548330e8c4e7..feb3d5542a62 100755 > --- a/scripts/export_report.pl > +++ b/scripts/export_report.pl > @@ -94,7 +94,7 @@ if (defined $opt{'o'}) { > # > while ( <$module_symvers> ) { > chomp; > - my (undef, $symbol, $namespace, $module, $gpl) = split('\t'); > + my (undef, $symbol, $module, $gpl, $namespace) = split('\t'); > $SYMBOL { $symbol } = [ $module , "0" , $symbol, $gpl]; > } > close($module_symvers); > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c > index a3d8370f9544..e1963ef8c07c 100644 > --- a/scripts/mod/modpost.c > +++ b/scripts/mod/modpost.c > @@ -2421,7 +2421,7 @@ static void write_if_changed(struct buffer *b, const char *fname) > } > > /* parse Module.symvers file. line format: > - * 0x12345678symbolmodule[[export]something] > + * 0x12345678symbolmoduleexportnamespace > **/ > static void read_dump(const char *fname, unsigned int kernel) > { > @@ -2434,7 +2434,7 @@ static void read_dump(const char *fname, unsigned int kernel) > return; > > while ((line = get_next_line(&pos, file, size))) { > - char *symname, *namespace, *modname, *d, *export, *end; > + char *symname, *namespace, *modname, *d, *export; > unsigned int crc; > struct module *mod; > struct symbol *s; > @@ -2442,16 +2442,16 @@ static void read_dump(const char *fname, unsigned int kernel) > if (!(symname = strchr(line, '\t'))) > goto fail; > *symname++ = '\0'; > - if (!(namespace = strchr(symname, '\t'))) > - goto fail; > - *namespace++ = '\0'; > - if (!(modname = strchr(namespace, '\t'))) > + if (!(modname = strchr(symname, '\t'))) > goto fail; > *modname++ = '\0'; > - if ((export = strchr(modname, '\t')) != NULL) > - *export++ = '\0'; > - if (export && ((end = strchr(export, '\t')) != NULL)) > - *end = '\0'; > + if (!(export = strchr(modname, '\t'))) > + goto fail; > + *export++ = '\0'; > + if (!(namespace = strchr(export, '\t'))) > + goto fail; > + *namespace++ = '\0'; > + > crc = strtoul(line, &d, 16); > if (*symname == '\0' || *modname == '\0' || *d != '\0') > goto fail; > @@ -2502,9 +2502,9 @@ static void write_dump(const char *fname) > namespace = symbol->namespace; > buf_printf(&buf, "0x%08x\t%s\t%s\t%s\t%s\n", > symbol->crc, symbol->name, > - namespace ? namespace : "", > symbol->module->name, > - export_str(symbol->export)); > + export_str(symbol->export), > + namespace ? namespace : ""); > } > symbol = symbol->next; > } > -- > 2.16.4 > -- Best Regards Masahiro Yamada