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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 263CCC4360C for ; Thu, 1 Apr 2021 18:03:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D63096112E for ; Thu, 1 Apr 2021 18:03:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236799AbhDASDY (ORCPT ); Thu, 1 Apr 2021 14:03:24 -0400 Received: from elvis.franken.de ([193.175.24.41]:44820 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236822AbhDAR6q (ORCPT ); Thu, 1 Apr 2021 13:58:46 -0400 Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1lRx0R-0006B4-00; Thu, 01 Apr 2021 15:05:03 +0200 Received: by alpha.franken.de (Postfix, from userid 1000) id 0A5EDC2095; Thu, 1 Apr 2021 14:51:00 +0200 (CEST) Date: Thu, 1 Apr 2021 14:51:00 +0200 From: Thomas Bogendoerfer To: Christoph Hellwig Cc: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 3/4] MIPS: uaccess: Remove get_fs/set_fs call sites Message-ID: <20210401125100.GA9556@alpha.franken.de> References: <20210331115603.146159-1-tsbogend@alpha.franken.de> <20210331115603.146159-4-tsbogend@alpha.franken.de> <20210401063055.GB25514@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210401063055.GB25514@lst.de> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Thu, Apr 01, 2021 at 08:30:55AM +0200, Christoph Hellwig wrote: > On Wed, Mar 31, 2021 at 01:56:00PM +0200, Thomas Bogendoerfer wrote: > > +#define __get_user_nofault(dst, src, type, err_label) \ > > +do { \ > > + int __gu_err; \ > > + \ > > + __get_user_common(*((type *)(dst)), sizeof(type), \ > > + (__force type *)(src)); \ > > + if (unlikely(__gu_err)) \ > > + goto err_label; \ > > +} while (0) > > + > > + > > +static inline int __get_addr(unsigned long *a, unsigned long *p, bool user) > > +{ > > + if (user) > > + __get_user_nofault(a, p, unsigned long, fault); > > + else > > + __get_kernel_nofault(a, p, unsigned long, fault); > > + > > + return 0; > > + > > +fault: > > + return -EFAULT; > > +} > > Why can't these use plain old get_user and get_kernel_nofault? > You "optimize" away the access_ok / get_kernel_nofaul_allowed checks > here, but now use totally non-standard and possibly dangerous APIs. thanks, I was too deep into the macro wormhole... using standard API makes this even look nicer. Posting v3 in a few minutes. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]