From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S939914AbdD1XDN (ORCPT ); Fri, 28 Apr 2017 19:03:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46610 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932404AbdD1XC4 (ORCPT ); Fri, 28 Apr 2017 19:02:56 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com C39D8248527 Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=bhe@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com C39D8248527 Date: Sat, 29 Apr 2017 07:02:51 +0800 From: Baoquan He To: YASUAKI ISHIMATSU Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, keescook@chromium.org, dyoung@redhat.com, douly.fnst@cn.fujitsu.com, dan.j.williams@intel.com Subject: Re: [PATCH v3 0/3] Handle memmap and mem kernel options in boot stage kaslr Message-ID: <20170428230251.GA12873@x1> References: <1493201772-19084-1-git-send-email-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.7.0 (2016-08-17) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 28 Apr 2017 23:02:56 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/27/17 at 03:57pm, YASUAKI ISHIMATSU wrote: > Hi Baoquan, > > > On 04/26/2017 06:16 AM, Baoquan He wrote: > > People reported kernel panic occurs during system boots up with mem boot option. > > After checking code, several problems are found about memmap= and mem= in boot stage > > kaslr. > > > > *) In commit f28442497b5c ("x86/boot: Fix KASLR and memmap= collision"), only one memmap > > entry is considered and only the last one if multiple memmap entries are specified. > > > > > *) mem= and memmap=nn[KMG] are not considered yet. They are used to limit max address > > of system. Kernel can't be randomized to be above the limit. > > I confirmed that mem= works correctly. > > Tested-by: Yasuaki Ishimatsu Thanks for your effort, Yasuaki Ishimatsu! > > > > > > *) kernel-parameters.txt doesn't tell the updated behaviour of memmap=. > > > > This patchset tries to solve above issues, and it sits on top of > > tip:x86/boot branch. > > > > Changelog > > > > v2->v3: > > No functionality change in this round. > > a)Use local static variable insted of global variable > > mem_avoid_memmap_index in patch 1/3. > > b)Fix a typo in patch 3/3. > > > > v1->v2: > > a)The original patch 1/4 has been put in tip:x86/boot and no update, > > so it's not included in this post. > > b)Use patch log Ingo reorganized. > > c)lib/ctype.c and lib/cmdline.c are needed for kaslr.c, while those > > EXPORT_SYMBOL(x) contained caused failure of build on 32-bit allmodconfig: > > ...... > > ld: -r and -shared may not be used together > > scripts/Makefile.build:294: recipe for target 'arch/x86/boot/compressed/kaslr.o' failed > > ...... > > Disabling the symbol exporting removes the build failure. > > d)Use dynamic allocation to allocate memory to contain copied kernel cmdline > > buffer, it's implemented in include/linux/decompress/mm.h. > > > > > > > > Baoquan He (3): > > KASLR: Parse all memmap entries in cmdline > > KASLR: Handle memory limit specified by memmap and mem option > > Documentation/kernel-parameters.txt: Update 'memmap=' option > > description > > > > Documentation/admin-guide/kernel-parameters.txt | 9 ++ > > arch/x86/boot/compressed/cmdline.c | 2 +- > > arch/x86/boot/compressed/kaslr.c | 183 +++++++++++++++--------- > > arch/x86/boot/string.c | 8 ++ > > 4 files changed, 136 insertions(+), 66 deletions(-) > >