From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f70.google.com (mail-pg0-f70.google.com [74.125.83.70]) by kanga.kvack.org (Postfix) with ESMTP id D5F936B0253 for ; Tue, 14 Nov 2017 19:37:36 -0500 (EST) Received: by mail-pg0-f70.google.com with SMTP id r12so10841018pgu.9 for ; Tue, 14 Nov 2017 16:37:36 -0800 (PST) Received: from mga11.intel.com (mga11.intel.com. [192.55.52.93]) by mx.google.com with ESMTPS id l63si2893294plb.468.2017.11.14.16.37.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 14 Nov 2017 16:37:36 -0800 (PST) Subject: Re: [kernel-hardening] Re: [PATCH v6 03/11] mm, x86: Add support for eXclusive Page Frame Ownership (XPFO) References: <20170907173609.22696-1-tycho@docker.com> <20170907173609.22696-4-tycho@docker.com> <34454a32-72c2-c62e-546c-1837e05327e1@intel.com> <20170920223452.vam3egenc533rcta@smitten> <97475308-1f3d-ea91-5647-39231f3b40e5@intel.com> <20170921000901.v7zo4g5edhqqfabm@docker> <20171110010907.qfkqhrbtdkt5y3hy@smitten> <7237ae6d-f8aa-085e-c144-9ed5583ec06b@intel.com> <2aa64bf6-fead-08cc-f4fe-bd353008ca59@intel.com> <20171115003358.r3bsukc3vlbikjef@cisco> From: Dave Hansen Message-ID: Date: Tue, 14 Nov 2017 16:37:34 -0800 MIME-Version: 1.0 In-Reply-To: <20171115003358.r3bsukc3vlbikjef@cisco> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tycho Andersen Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com, Marco Benatto , Juerg Haefliger , x86@kernel.org On 11/14/2017 04:33 PM, Tycho Andersen wrote: >> >> void set_bh_page(struct buffer_head *bh, >> ... >> bh->b_data = page_address(page) + offset; > Ah, yes. I guess there will be many bugs like this :). Anyway, I'll > try to cook up a patch. It won't catch all the bugs, but it might be handy to have a debugging mode that records the location of the last user of page_address() and friends. That way, when we trip over an unmapped page, we have an easier time finding the offender. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org