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=-5.8 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 C3E31C433E7 for ; Wed, 2 Sep 2020 15:34:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A929520767 for ; Wed, 2 Sep 2020 15:34:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726800AbgIBPTU (ORCPT ); Wed, 2 Sep 2020 11:19:20 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:32713 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727821AbgIBPRy (ORCPT ); Wed, 2 Sep 2020 11:17:54 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4BhSHF0YFGz9tySq; Wed, 2 Sep 2020 17:17:45 +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 VNiYSj_8XU-g; Wed, 2 Sep 2020 17:17:45 +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 4BhSHD6TLCz9tySn; Wed, 2 Sep 2020 17:17:44 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 54AFA8B7ED; Wed, 2 Sep 2020 17:17:46 +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 Ob8p81vLm4sB; Wed, 2 Sep 2020 17:17:46 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 9FF028B7EA; Wed, 2 Sep 2020 17:17:45 +0200 (CEST) Subject: Re: [PATCH 10/10] powerpc: remove address space overrides using set_fs() To: Christoph Hellwig Cc: Linus Torvalds , Al Viro , Michael Ellerman , x86@kernel.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Kees Cook , linux-kernel@vger.kernel.org References: <20200827150030.282762-1-hch@lst.de> <20200827150030.282762-11-hch@lst.de> <8974838a-a0b1-1806-4a3a-e983deda67ca@csgroup.eu> <20200902123646.GA31184@lst.de> From: Christophe Leroy Message-ID: Date: Wed, 2 Sep 2020 17:17:34 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200902123646.GA31184@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Sender: linux-arch-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org Le 02/09/2020 à 14:36, Christoph Hellwig a écrit : > On Wed, Sep 02, 2020 at 08:15:12AM +0200, Christophe Leroy wrote: >>> - return 0; >>> - return (size == 0 || size - 1 <= seg.seg - addr); >>> + if (addr >= TASK_SIZE_MAX) >>> + return false; >>> + if (size == 0) >>> + return false; >> >> __access_ok() was returning true when size == 0 up to now. Any reason to >> return false now ? > > No, this is accidental and broken. Can you re-run your benchmark with > this fixed? > With this fix, I get root@vgoippro:~# time dd if=/dev/zero of=/dev/null count=1M 1048576+0 records in 1048576+0 records out 536870912 bytes (512.0MB) copied, 6.776327 seconds, 75.6MB/s real 0m 6.78s user 0m 1.64s sys 0m 5.13s That's still far from the 91.7MB/s I get with 5.9-rc2, but better than the 65.8MB/s I got yesterday with your series. Still some way to go thought. Christophe