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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 35806C1975A for ; Thu, 12 Mar 2020 07:17:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B71D206F7 for ; Thu, 12 Mar 2020 07:17:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qCRa/6q0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388062AbgCLHR4 (ORCPT ); Thu, 12 Mar 2020 03:17:56 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:52327 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387958AbgCLHRz (ORCPT ); Thu, 12 Mar 2020 03:17:55 -0400 Received: by mail-wm1-f65.google.com with SMTP id 11so4870199wmo.2; Thu, 12 Mar 2020 00:17:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=4jiBmksMrMfFbIHa3ZewzTbMHCps2UU4whG+wAJNTBQ=; b=qCRa/6q0ILq9l3DfKMhKjmfdCWyj5jDt69VIemin4LMyIWEMIFzpkX/xk15bh7a8Va WCi0by+fzbYYP1L/GdgW9RifNdtxSKaVoaZZCr6XwYxPSVmfnPHy/HiQ2KqQOS5GGsMc VCcGT160rohacuTPb7tz+9cIQE/RhLYy+mjeKxZnbOLptIxIYLsMRCfJ02S+srINTdAw YnPTNvWnkgfg6UFyM38nMvPdxDEU2ZJvcsHW1zL4gt0YsRmBDZPALVOKkkwGHNRJL5qP eB7mFiU5tq2xWkCGr+8kbsy/2vaOdCpUeCLhkc5GtoCFc00/LDHL2ClpsEVPwhUV/qJ+ srAg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=4jiBmksMrMfFbIHa3ZewzTbMHCps2UU4whG+wAJNTBQ=; b=CSKRsUi5sBIsffZEr3gI1+IX6cdf7XqQWQiysRY8dbCZOG83i5TBk8dQrZebJilXkN yUX0074ms7jG+fyYegZsmGQjuPaojSkh/3OB26UvHj/qtpdNZJKsILVsVevloe9mwUIV hcYwEx+W9jynZJCzThDtTUYjrzdxom/zvlAR803/PyVX+XQgrA/FmRJ3i8LdxIzhHzL+ AqpddU5+A76+noHZL87p+PwyoSREdWUBDNfKev0928AL4fOvxJHvfq4uFUfpKHf6NSGG ntttwUABcwFZrkQU+w7onvpMhXzX30igpEqNEjPAQjjfxvBwqfuvQkQiTBnUGiuezVMg IXdg== X-Gm-Message-State: ANhLgQ07Vx8pe9+agzxGBdR8UpvuekJrW8WgHdmaaZYl3Uk/RmKOZqar i1Fj/LJh18iYx2nIMcTAa2AW4Bnx6K64j/DERtgVSy/o X-Google-Smtp-Source: ADFU+vuna7/EkiqUm3Pt6MoBfapvFtfi/fNt7GNXfSGcalppqq7tD082k1sG+OIOruCLHe89OYG9o8CT7dwYHJJJ7f0= X-Received: by 2002:a05:600c:d8:: with SMTP id u24mr3264837wmm.165.1583997471183; Thu, 12 Mar 2020 00:17:51 -0700 (PDT) MIME-Version: 1.0 References: <20200311170120.12641-1-jeyu@kernel.org> In-Reply-To: <20200311170120.12641-1-jeyu@kernel.org> From: Lucas De Marchi Date: Thu, 12 Mar 2020 00:17:39 -0700 Message-ID: Subject: Re: [PATCH v2] modpost: move the namespace field in Module.symvers last To: Jessica Yu Cc: Masahiro Yamada , Matthias Maennich , stable@vger.kernel.org, lkml 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 Wed, Mar 11, 2020 at 10:02 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 > --- > v2: > > - Explain the changes to read_dump() and the comment (and provide > historical context) in the commit message. (Lucas De Marchi) Great, thanks for fixing this. 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 > -- Lucas De Marchi