From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753342AbcA2Dyu (ORCPT ); Thu, 28 Jan 2016 22:54:50 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:60350 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752218AbcA2Dyt (ORCPT ); Thu, 28 Jan 2016 22:54:49 -0500 From: "Rafael J. Wysocki" To: Laura Abbott Cc: Andrew Morton , "Kirill A. Shutemov" , Vlastimil Babka , Michal Hocko , Pavel Machek , Len Brown , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, Kees Cook , linux-pm@vger.kernel.org Subject: Re: [PATCHv2 2/2] mm/page_poisoning.c: Allow for zero poisoning Date: Fri, 29 Jan 2016 04:55:44 +0100 Message-ID: <2210767.i4rORgf7qQ@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.5.0-rc1+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1454035099-31583-3-git-send-email-labbott@fedoraproject.org> References: <1454035099-31583-1-git-send-email-labbott@fedoraproject.org> <1454035099-31583-3-git-send-email-labbott@fedoraproject.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, January 28, 2016 06:38:19 PM Laura Abbott wrote: > By default, page poisoning uses a poison value (0xaa) on free. If this > is changed to 0, the page is not only sanitized but zeroing on alloc > with __GFP_ZERO can be skipped as well. The tradeoff is that detecting > corruption from the poisoning is harder to detect. This feature also > cannot be used with hibernation since pages are not guaranteed to be > zeroed after hibernation. > > Credit to Grsecurity/PaX team for inspiring this work > > Signed-off-by: Laura Abbott The hibernation disabling part is fine by me. Please feel free to add an ACK from me to this if that helps. Thanks, Rafael