From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751445AbdEMFqk (ORCPT ); Sat, 13 May 2017 01:46:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40212 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750935AbdEMFqj (ORCPT ); Sat, 13 May 2017 01:46:39 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 06609369C3 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=bhe@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 06609369C3 From: Baoquan He To: tglx@linutronix.de, keescook@chromium.org, mingo@kernel.org, m.mizuma@jp.fujitsu.com Cc: linux-kernel@vger.kernel.org, dyoung@redhat.com, douly.fnst@cn.fujitsu.com, dan.j.williams@intel.com, hpa@zytor.com, x86@kernel.org, Baoquan He Subject: [PATCH v5 0/3] Handle memmap and mem kernel options in boot stage kaslr Date: Sat, 13 May 2017 13:46:27 +0800 Message-Id: <1494654390-23861-1-git-send-email-bhe@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Sat, 13 May 2017 05:46:39 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. *) 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 v4->v5: 1. Change patch log according to Thomas's comment. 2. Put "Fall through" to the right place in parse_memmap() according to Kees's suggestion. v3->v4: 1. Code improved patch 1/3 according to Kees's suggestion. 2. Add 'Fall through' in switch case of parse_memmap() which is suggestd by Kees. v2->v3: No functionality change in this round. 1. Use local static variable insted of global variable mem_avoid_memmap_index in patch 1/3. 2. Fix a typo in patch 3/3. v1->v2: 1. The original patch 1/4 has been put in tip:x86/boot and no update, so it's not included in this post. 2. Use patch log Ingo reorganized. 3. 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. 4. 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 command line 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 | 190 ++++++++++++++++-------- arch/x86/boot/string.c | 8 + 4 files changed, 143 insertions(+), 66 deletions(-) -- 2.5.5