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=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 266E0C43A1D for ; Thu, 12 Jul 2018 12:32:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0FAF208E9 for ; Thu, 12 Jul 2018 12:32:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E0FAF208E9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732416AbeGLMlw (ORCPT ); Thu, 12 Jul 2018 08:41:52 -0400 Received: from mx2.suse.de ([195.135.220.15]:40190 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726663AbeGLMlw (ORCPT ); Thu, 12 Jul 2018 08:41:52 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id C845DADAD; Thu, 12 Jul 2018 12:32:28 +0000 (UTC) Date: Thu, 12 Jul 2018 14:32:28 +0200 From: Michal Hocko To: Chao Fan Cc: Dou Liyang , Baoquan He , akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org, yasu.isimatu@gmail.com, keescook@chromium.org, indou.takao@jp.fujitsu.com, caoj.fnst@cn.fujitsu.com, vbabka@suse.cz, mgorman@techsingularity.net Subject: Re: Bug report about KASLR and ZONE_MOVABLE Message-ID: <20180712123228.GK32648@dhcp22.suse.cz> References: <20180711094244.GA2019@localhost.localdomain> <20180711104158.GE2070@MiWiFi-R3L-srv> <20180711104944.GG1969@MiWiFi-R3L-srv> <20180711124008.GF2070@MiWiFi-R3L-srv> <72721138-ba6a-32c9-3489-f2060f40a4c9@cn.fujitsu.com> <20180712060115.GD6742@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180712060115.GD6742@localhost.localdomain> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 12-07-18 14:01:15, Chao Fan wrote: > On Thu, Jul 12, 2018 at 01:49:49PM +0800, Dou Liyang wrote: > >Hi Baoquan, > > > >At 07/11/2018 08:40 PM, Baoquan He wrote: > >> Please try this v3 patch: > >> >>From 9850d3de9c02e570dc7572069a9749a8add4c4c7 Mon Sep 17 00:00:00 2001 > >> From: Baoquan He > >> Date: Wed, 11 Jul 2018 20:31:51 +0800 > >> Subject: [PATCH v3] mm, page_alloc: find movable zone after kernel text > >> > >> In find_zone_movable_pfns_for_nodes(), when try to find the starting > >> PFN movable zone begins in each node, kernel text position is not > >> considered. KASLR may put kernel after which movable zone begins. > >> > >> Fix it by finding movable zone after kernel text on that node. > >> > >> Signed-off-by: Baoquan He > > > > > >You fix this in the _zone_init side_. This may make the 'kernelcore=' or > >'movablecore=' failed if the KASLR puts the kernel back the tail of the > >last node, or more. > > I think it may not fail. > There is a 'restart' to do another pass. > > > > >Due to we have fix the mirror memory in KASLR side, and Chao is trying > >to fix the 'movable_node' in KASLR side. Have you had a chance to fix > >this in the KASLR side. > > > > I think it's better to fix here, but not KASLR side. > Cause much more code will be change if doing it in KASLR side. > Since we didn't parse 'kernelcore' in compressed code, and you can see > the distribution of ZONE_MOVABLE need so much code, so we do not need > to do so much job in KASLR side. But here, several lines will be OK. I am not able to find the beginning of the email thread right now. Could you summarize what is the actual problem please? -- Michal Hocko SUSE Labs