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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 D82F5C433DF for ; Fri, 16 Oct 2020 13:18:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CE6520848 for ; Fri, 16 Oct 2020 13:18:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407409AbgJPNSU (ORCPT ); Fri, 16 Oct 2020 09:18:20 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:22976 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405204AbgJPNST (ORCPT ); Fri, 16 Oct 2020 09:18:19 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4CCRY41Zymz9vBmK; Fri, 16 Oct 2020 15:18:16 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id WcPndnQa-D6T; Fri, 16 Oct 2020 15:18:16 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4CCRY40LN6z9vBmJ; Fri, 16 Oct 2020 15:18:16 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 8FD298B849; Fri, 16 Oct 2020 15:18:17 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id LwNT5LCO5_Ue; Fri, 16 Oct 2020 15:18:17 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 39B498B83E; Fri, 16 Oct 2020 15:18:17 +0200 (CEST) Subject: Re: [PATCH 1/8] powerpc/uaccess: Add unsafe_copy_from_user To: Christoph Hellwig , "Christopher M. Riedl" Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk References: <20201015150159.28933-1-cmr@codefail.de> <20201015150159.28933-2-cmr@codefail.de> <20201016065403.GA9343@infradead.org> From: Christophe Leroy Message-ID: <479b67b8-0caf-ebcb-433d-5739d71bdadf@csgroup.eu> Date: Fri, 16 Oct 2020 15:18:08 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: <20201016065403.GA9343@infradead.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 16/10/2020 à 08:54, Christoph Hellwig a écrit : > On Thu, Oct 15, 2020 at 10:01:52AM -0500, Christopher M. Riedl wrote: >> Implement raw_copy_from_user_allowed() which assumes that userspace read >> access is open. Use this new function to implement raw_copy_from_user(). >> Finally, wrap the new function to follow the usual "unsafe_" convention >> of taking a label argument. The new raw_copy_from_user_allowed() calls >> __copy_tofrom_user() internally, but this is still safe to call in user >> access blocks formed with user_*_access_begin()/user_*_access_end() >> since asm functions are not instrumented for tracing. > > Please also add a fallback unsafe_copy_from_user to linux/uaccess.h > so this can be used as a generic API. > I guess this can be done in a separate patch independant of that series ? Christophe