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 358A8C4360C for ; Thu, 10 Oct 2019 18:35:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0C4D320B7C for ; Thu, 10 Oct 2019 18:35:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0C4D320B7C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 8A1E68E0005; Thu, 10 Oct 2019 14:35:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8508D8E0003; Thu, 10 Oct 2019 14:35:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7664A8E0005; Thu, 10 Oct 2019 14:35:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0114.hostedemail.com [216.40.44.114]) by kanga.kvack.org (Postfix) with ESMTP id 55ADA8E0003 for ; Thu, 10 Oct 2019 14:35:27 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id D1E31812F for ; Thu, 10 Oct 2019 18:35:26 +0000 (UTC) X-FDA: 76028727852.20.lake77_4ca053453d22d X-HE-Tag: lake77_4ca053453d22d X-Filterd-Recvd-Size: 1480 Received: from gentwo.org (gentwo.org [3.19.106.255]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Thu, 10 Oct 2019 18:35:26 +0000 (UTC) Received: by gentwo.org (Postfix, from userid 1002) id 016993F1BF; Thu, 10 Oct 2019 18:35:25 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by gentwo.org (Postfix) with ESMTP id 0043B3E86A; Thu, 10 Oct 2019 18:35:25 +0000 (UTC) Date: Thu, 10 Oct 2019 18:35:25 +0000 (UTC) From: Christopher Lameter X-X-Sender: cl@www.lameter.com To: Matthew Wilcox cc: Shyam Saini , linux-mm@kvack.org, kernel-hardening@lists.openwall.com, Kees Cook Subject: Re: [PATCH] slab: Redefine ZERO_SIZE_PTR to include ERR_PTR range In-Reply-To: <20191010174413.GT32665@bombadil.infradead.org> Message-ID: References: <20191010103151.7708-1-mayhs11saini@gmail.com> <20191010174413.GT32665@bombadil.infradead.org> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Bogosity: Ham, tests=bogofilter, spamicity=0.000022, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, 10 Oct 2019, Matthew Wilcox wrote: > I was wondering about something like that too, but allocating zero bytes > isn't actually an error, and if we have code that does something like: True. But it is in a greyzone. You cannot store anything in zero bytes after all.