From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752183AbdCDO0I (ORCPT ); Sat, 4 Mar 2017 09:26:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39244 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751927AbdCDO0H (ORCPT ); Sat, 4 Mar 2017 09:26:07 -0500 Date: Sat, 4 Mar 2017 22:26:02 +0800 From: Baoquan He To: mingo@redhat.com Cc: linux-kernel@vger.kernel.org, x86@kernel.org, keescook@chromium.org, tglx@linutronix.de, hpa@zytor.com, yinghai@kernel.org, bp@suse.de, anderson@redhat.com, luto@kernel.org, thgarnie@google.com, kuleshovmail@gmail.com Subject: Re: [PATCH v4 0/3] x86/64/KASLR: Change kernel mapping size to 1G unconditionally Message-ID: <20170304142602.GC12083@x1> References: <1486040077-3719-1-git-send-email-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1486040077-3719-1-git-send-email-bhe@redhat.com> 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]); Sat, 04 Mar 2017 14:26:07 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ingo, Ping! Could you please help have a look at thie patchset and give comments or any suggestion? Checked the git history, you have been taking care of the KERNEL_IMAGE_SIZE value changing. Now Kees added his Reviewed-by, Boris agreed on setting the size of space for kernel mapping to 1G by default but he doesn't like the adding KERNEL_MAPPING_SIZE constant idea. Your suggestion is much appreciated! Thanks Baoquan On 02/02/17 at 08:54pm, Baoquan He wrote: > This is v4 post. > > In the previous 3 versions I tried to detect and determine kernel image > mapping size at runtime for x86_64. With this the inconsistency between > KASLR code is not compiled in by disabling CONFIG_RANDOMIZE_BASE and > KASLR code is compiled in but add 'nokaslr' kernel option can be fixed. > > When review v3 Boris suggested we should change kernel mapping size to > 1G directly, but not an option. Kees explained he made kernel mapping > size as an option mainly because he woried about kernel module space. > He said it wasn't clear to him at the time if enough space remained for > modules in all use-cases. Then Boris pointed out that practically kaslr > will be enabled on the majority of the systems anyway, and the reduction > of kernel modules mapping space has been there for a while now, if so we > probably whould've heard complaints already. Kees agreed. > > So in this version of post change kernel mapping size of x86 64 to 1G > as Boris suggested. Then the inconsistency will naturally disappear. > > And I still keep patch 1/3 which introduces the new constant > KERNEL_MAPPING_SIZE. And let KERNEL_IMAGE_SIZE stay for restricting kernel > image size during linking stage. > > > v3->v4: > Change kernel mapping size to 1G unconditionally as Boris suggested. > > v2->v3: > Boris pointed out patch log is not good for reviewing and understanding. > So split the old patch 2/2 into 2 parts and rewrite the patch log, > patch 2/3 is introducing the new constant KERNEL_MAPPING_SIZE which > differs from the old KERNEL_IMAGE_SIZE, patch 3/3 gets the kernel mapping > size at runtime. > > v1->v2: > Kbuild test threw build warning because of code bug. > > > Baoquan He (3): > x86: Introduce a new constant KERNEL_MAPPING_SIZE > x86/64/KASLR: Change kernel mapping size to 1G unconditionally > x86/64/doc: Update the ranges of kernel text and modules mapping > > Documentation/x86/x86_64/mm.txt | 4 ++-- > arch/x86/boot/compressed/kaslr.c | 10 +++++----- > arch/x86/include/asm/page_32_types.h | 6 ++++++ > arch/x86/include/asm/page_64_types.h | 17 ++++++++--------- > arch/x86/include/asm/pgtable_64_types.h | 2 +- > arch/x86/kernel/head64.c | 4 ++-- > arch/x86/kernel/head_64.S | 12 +++++------- > arch/x86/kernel/machine_kexec_64.c | 2 +- > arch/x86/mm/init_64.c | 2 +- > arch/x86/mm/physaddr.c | 6 +++--- > 10 files changed, 34 insertions(+), 31 deletions(-) > > -- > 2.5.5 >