From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754669AbeCGR1C (ORCPT ); Wed, 7 Mar 2018 12:27:02 -0500 Received: from mail-pl0-f65.google.com ([209.85.160.65]:38272 "EHLO mail-pl0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754248AbeCGR1A (ORCPT ); Wed, 7 Mar 2018 12:27:00 -0500 X-Google-Smtp-Source: AG47ELvwtrzn/SKlq8FpQ5RUGevXq5sUJzE/9obWW0aXUTBtP2xHil6c+RtTUoj7FgKWYYsanBRYiQ== Subject: Re: [PATCH 6/7] lkdtm: crash on overwriting protected pmalloc var To: Igor Stoppa , david@fromorbit.com, willy@infradead.org, keescook@chromium.org, mhocko@kernel.org Cc: labbott@redhat.com, linux-security-module@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com References: <20180228200620.30026-1-igor.stoppa@huawei.com> <20180228200620.30026-7-igor.stoppa@huawei.com> <1723ee8d-c89e-0704-c2c3-254eda39dc8b@gmail.com> <6378e63e-174f-642e-d319-1d121b74d3d7@huawei.com> From: J Freyensee Message-ID: <2664691b-4d48-1701-8dae-774ec7733f61@gmail.com> Date: Wed, 7 Mar 2018 09:26:55 -0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <6378e63e-174f-642e-d319-1d121b74d3d7@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/7/18 5:18 AM, Igor Stoppa wrote: > > On 06/03/18 19:20, J Freyensee wrote: > >> On 2/28/18 12:06 PM, Igor Stoppa wrote: > [...] > >>> void __init lkdtm_perms_init(void); >>> void lkdtm_WRITE_RO(void); >>> void lkdtm_WRITE_RO_AFTER_INIT(void); >>> +void lkdtm_WRITE_RO_PMALLOC(void); >> Does this need some sort of #ifdef too? > Not strictly. It's just a function declaration. > As long as it is not used, the linker will not complain. > The #ifdef placed around the use and definition is sufficient, from a > correctness perspective. > > But it's a different question if there is any standard in linux about > hiding also the declaration. I'd prefer hiding it if it's contents are being ifdef'ed out, but I really think it's more of a maintainer preference question. > > I am not very fond of #ifdefs, so when I can I try to avoid them. > >