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,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 32FDFC433E2 for ; Wed, 2 Sep 2020 12:39:55 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D422920767 for ; Wed, 2 Sep 2020 12:39:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D422920767 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4BhNn32lfFzDqlm for ; Wed, 2 Sep 2020 22:39:51 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=lst.de Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4BhNjd4KcpzDq9b for ; Wed, 2 Sep 2020 22:36:52 +1000 (AEST) Received: by verein.lst.de (Postfix, from userid 2407) id C9AC368B02; Wed, 2 Sep 2020 14:36:46 +0200 (CEST) Date: Wed, 2 Sep 2020 14:36:46 +0200 From: Christoph Hellwig To: Christophe Leroy Subject: Re: [PATCH 10/10] powerpc: remove address space overrides using set_fs() Message-ID: <20200902123646.GA31184@lst.de> References: <20200827150030.282762-1-hch@lst.de> <20200827150030.282762-11-hch@lst.de> <8974838a-a0b1-1806-4a3a-e983deda67ca@csgroup.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8974838a-a0b1-1806-4a3a-e983deda67ca@csgroup.eu> User-Agent: Mutt/1.5.17 (2007-11-01) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Kees Cook , x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Al Viro , linux-fsdevel@vger.kernel.org, Linus Torvalds , Christoph Hellwig Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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?