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 70551C433FE for ; Wed, 27 Apr 2022 08:42:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359517AbiD0Ipm (ORCPT ); Wed, 27 Apr 2022 04:45:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50440 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244977AbiD0Iph (ORCPT ); Wed, 27 Apr 2022 04:45:37 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4595984ED5 for ; Wed, 27 Apr 2022 01:42:26 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id D0F7EB82539 for ; Wed, 27 Apr 2022 08:42:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05125C385A7; Wed, 27 Apr 2022 08:42:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1651048943; bh=fKFAg7yyRNNSgvuezxx6sbeGgfw2ClQ/UPWWRA3anwA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=u5hCz4A6L3BxKUDH6/UROdADwrk0z5m42iU59prw/wC1NtIpgsjTEyurZp3wA7kSF bfAzj1Yh4MqYIIeJau2o7THzXLdEp/TLvKqx4fLVtXzm1Q7DbgJJcte+BdzmfUg4om eZMaRqGnYj5zHK7BJyvWDImPv76ybNgdaPVo2kv4= Date: Wed, 27 Apr 2022 10:42:20 +0200 From: Greg Kroah-Hartman To: Masahiro Yamada Cc: Linux Kernel Mailing List , Miroslav Benes , Emil Velikov , Jessica Yu , Quentin Perret , Matthias Maennich Subject: Re: [PATCH] export: fix string handling of namespace in EXPORT_SYMBOL_NS Message-ID: References: <20220108140415.3360088-1-gregkh@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 12, 2022 at 04:14:00AM +0900, Masahiro Yamada wrote: > On Sat, Jan 8, 2022 at 11:04 PM Greg Kroah-Hartman > wrote: > > > > Commit c3a6cf19e695 ("export: avoid code duplication in > > include/linux/export.h") broke the ability for a defined string to be > > used as a namespace value. Fix this up by adding another layer of > > indirection to preserve the previous functionality. > > > > Fixes: c3a6cf19e695 ("export: avoid code duplication in include/linux/export.h") > > Cc: Miroslav Benes > > Cc: Emil Velikov > > Cc: Jessica Yu > > Cc: Quentin Perret > > Cc: Masahiro Yamada > > Cc: Matthias Maennich > > Signed-off-by: Greg Kroah-Hartman > > --- > > Note, I found this while forward porting an out-of-tree Android kernel > > patch from 5.4 to 5.10 that used module namespaces to help wall-off vfs > > symbols from being used by non-filesystem modules. This issue does not > > affect any in-kernel code, so I am not so sure if it really is needed > > here, but it does restore the previous functionality that was being used > > in older kernels so it might be good to put back in case others want to > > do much the same thing. > > > > include/linux/export.h | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/include/linux/export.h b/include/linux/export.h > > index 27d848712b90..9a992809f57d 100644 > > --- a/include/linux/export.h > > +++ b/include/linux/export.h > > @@ -162,8 +162,10 @@ struct kernel_symbol { > > > > #define EXPORT_SYMBOL(sym) _EXPORT_SYMBOL(sym, "") > > #define EXPORT_SYMBOL_GPL(sym) _EXPORT_SYMBOL(sym, "_gpl") > > -#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", #ns) > > -#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "_gpl", #ns) > > +#define _EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", #ns) > > +#define _EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "_gpl", #ns) > > +#define EXPORT_SYMBOL_NS(sym, ns) _EXPORT_SYMBOL_NS(sym, ns) > > +#define EXPORT_SYMBOL_NS_GPL(sym, ns) _EXPORT_SYMBOL_NS_GPL(sym, ns) > > > > #endif /* !__ASSEMBLY__ */ > > > > -- > > 2.34.1 > > > > I see __stringify() a few files above. > So, you can use it here as well. > > > Does the following code work? (untested) > > > > > > diff --git a/include/linux/export.h b/include/linux/export.h > index 27d848712b90..5910ccb66ca2 100644 > --- a/include/linux/export.h > +++ b/include/linux/export.h > @@ -2,6 +2,8 @@ > #ifndef _LINUX_EXPORT_H > #define _LINUX_EXPORT_H > > +#include > + > /* > * Export symbols from the kernel to modules. Forked from module.h > * to reduce the amount of pointless cruft we feed to gcc when only > @@ -154,7 +156,6 @@ struct kernel_symbol { > #endif /* CONFIG_MODULES */ > > #ifdef DEFAULT_SYMBOL_NAMESPACE > -#include > #define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, > __stringify(DEFAULT_SYMBOL_NAMESPACE)) > #else > #define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, "") > @@ -162,8 +163,8 @@ struct kernel_symbol { > > #define EXPORT_SYMBOL(sym) _EXPORT_SYMBOL(sym, "") > #define EXPORT_SYMBOL_GPL(sym) _EXPORT_SYMBOL(sym, "_gpl") > -#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", #ns) > -#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "_gpl", #ns) > +#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", > __stringify(ns)) > +#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "_gpl", > __stringify(ns)) > > #endif /* !__ASSEMBLY__ */ Sorry for the long delay, but yes, this does seem to resolve the issue for me. I'll respin this and resend, thanks! greg k-h