Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031550AbbKDSwB (ORCPT ); Wed, 4 Nov 2015 13:52:01 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52288 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031287AbbKDSv6 (ORCPT ); Wed, 4 Nov 2015 13:51:58 -0500 Subject: Re: [PATCH 0/2] Support for set_memory_* outside of module space To: Kees Cook , Laura Abbott References: <1446587315-18145-1-git-send-email-labbott@fedoraproject.org> Cc: Catalin Marinas , Will Deacon , "linux-arm-kernel@lists.infradead.org" , LKML , Xishi Qiu , Ard Biesheuvel , Mark Rutland From: Laura Abbott Message-ID: <563A53CB.8000103@redhat.com> Date: Wed, 4 Nov 2015 10:51:55 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1942 Lines: 49 On 11/03/2015 03:42 PM, Kees Cook wrote: > On Tue, Nov 3, 2015 at 1:48 PM, Laura Abbott wrote: >> >> Hi, >> >> Based on a recent discussion[1] there is interest in having set_memory_* work >> on kernel memory for security and other use cases. This patch adds the >> ability for that to happen behind a kernel option. If this is welcome enough, >> the Kconfig can be dropped. This has been briefly tested but not stress tested. >> >> Thanks, >> Laura >> >> [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-October/382079.html >> >> Laura Abbott (2): >> arm64: Get existing page protections in split_pmd >> arm64: Allow changing of attributes outside of modules >> >> arch/arm64/Kconfig.debug | 11 +++++++ >> arch/arm64/mm/mm.h | 3 ++ >> arch/arm64/mm/mmu.c | 11 ++++--- >> arch/arm64/mm/pageattr.c | 74 ++++++++++++++++++++++++++++++++++++++++++++---- >> 4 files changed, 88 insertions(+), 11 deletions(-) > > This seems like the right thing to have. What's arm64 doing for the > equivalent of x86 and arm's set_kernel_text_* functions? x86 and arm > call their set_memory_* functions, for example. A quick examination > shows mm/mmu.c is just doing it "by hand" in fixup_executable and > mark_rodata_ro? Could those functions use the new set_memory_* ones? > It looks like mark_rodata_ro could probably use the set_memory_ro. I'll have to test it out. Longer term, the page table setup code should probably just be pulled out into a common file. Do you know the code path in ftrace which would trigger the set_kernel_text_* If not, I'll go see if I can figure out if it's implemented yet on arm64. > -Kees > Thanks, Laura -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/