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=-2.3 required=3.0 tests=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 371DAC47255 for ; Sun, 10 May 2020 01:04:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B66220735 for ; Sun, 10 May 2020 01:04:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728737AbgEJBEY (ORCPT ); Sat, 9 May 2020 21:04:24 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:59364 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725927AbgEJBEY (ORCPT ); Sat, 9 May 2020 21:04:24 -0400 Received: from fsav107.sakura.ne.jp (fsav107.sakura.ne.jp [27.133.134.234]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 04A14KL4042726; Sun, 10 May 2020 10:04:20 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav107.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav107.sakura.ne.jp); Sun, 10 May 2020 10:04:20 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav107.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 04A14KVP042723 (version=TLSv1.2 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 10 May 2020 10:04:20 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Subject: Re: [PATCH 05/20] tomoyo_write_control(): get rid of pointless access_ok() To: Linus Torvalds Cc: Al Viro , Linux Kernel Mailing List , linux-fsdevel References: <20200509234124.GM23230@ZenIV.linux.org.uk> <20200509234557.1124086-1-viro@ZenIV.linux.org.uk> <20200509234557.1124086-5-viro@ZenIV.linux.org.uk> From: Tetsuo Handa Message-ID: Date: Sun, 10 May 2020 10:04:16 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/05/10 9:57, Linus Torvalds wrote: > On Sat, May 9, 2020 at 5:51 PM Tetsuo Handa > wrote: >> >> I think that this access_ok() check helps reducing partial writes (either >> "whole amount was processed" or "not processed at all" unless -ENOMEM). > > No it doesn't. > > "access_ok()" only checks the range being a valid user address range. > I see. Thank you. Acked-by: Tetsuo Handa