From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chao Fan Subject: Re: [PATCH v7 1/3] x86/boot: Add acpitb.c to parse acpi tables Date: Tue, 25 Sep 2018 09:12:46 +0800 Message-ID: <20180925011246.GB12561@localhost.localdomain> References: <20180913104629.5179-1-fanc.fnst@cn.fujitsu.com> <20180913104629.5179-2-fanc.fnst@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Kees Cook Cc: linux-efi , ACPI Devel Maling List , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , X86 ML , LKML , Baoquan He , "Rafael J. Wysocki" , Len Brown , Ard Biesheuvel , indou.takao@jp.fujitsu.com, caoj.fnst@cn.fujitsu.com List-Id: linux-acpi@vger.kernel.org On Sat, Sep 22, 2018 at 08:45:12AM -0700, Kees Cook wrote: >On Thu, Sep 13, 2018 at 3:46 AM, Chao Fan wrote: >> There is a bug that kaslr may randomly chooses some positions >> which are located in movable memory regions. This will break memory >> hotplug feature and make the movable memory chosen by KASLR can't be >> removed. So dig SRAT table from ACPI tables to get memory information. >> >> Imitate the ACPI code of parsing ACPI tables to dig and read ACPI >> tables. Since some operations are not needed here, functions are >> simplified. Functions will be used to dig only SRAT tables to get >> information of memory, so that KASLR can the memory in immovable node. >> >> And also, these functions won't influence the initialization of >> ACPI after start_kernel(). >> >> Since use physical address directely, so acpi_os_map_memory() >> and acpi_os_unmap_memory() are not needed. >> >> Signed-off-by: Chao Fan >> --- >> arch/x86/boot/compressed/Makefile | 4 + >> arch/x86/boot/compressed/acpitb.c | 401 ++++++++++++++++++++++++++++++ > >Does this logic live anywhere else in the kernel already? (i.e. could >other code be reused?) Live in uncompressec period, but not completely same. The map between physical address and virtual address is not needed here. So I thins it's hard to reuse, that's why I made this new file. Thanks, Chao Fan > >-Kees > >-- >Kees Cook >Pixel Security > >