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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 25580C3A59F for ; Tue, 27 Aug 2019 00:39:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9B7920850 for ; Tue, 27 Aug 2019 00:39:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728032AbfH0Ajv (ORCPT ); Mon, 26 Aug 2019 20:39:51 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:5216 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726307AbfH0Ajv (ORCPT ); Mon, 26 Aug 2019 20:39:51 -0400 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id B0158D1E3D01EE54B123; Tue, 27 Aug 2019 08:39:47 +0800 (CST) Received: from [127.0.0.1] (10.177.96.203) by DGGEMS408-HUB.china.huawei.com (10.3.19.208) with Microsoft SMTP Server id 14.3.439.0; Tue, 27 Aug 2019 08:39:40 +0800 Subject: Re: [PATCH v6 00/12] implement KASLR for powerpc/fsl_booke/32 From: Jason Yan To: , , , , , , , , CC: , , , , , , References: <20190809100800.5426-1-yanaijie@huawei.com> Message-ID: <529fd908-42d6-f96f-daa2-9010f3035879@huawei.com> Date: Tue, 27 Aug 2019 08:39:38 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.177.96.203] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A polite ping :) What else should I do now? Thanks On 2019/8/19 14:12, Jason Yan wrote: > Hi Michael, > > Is there anything more I should do to get this feature meeting the > requirements of the mainline? > > Thanks, > Jason > > On 2019/8/9 18:07, Jason Yan wrote: >> This series implements KASLR for powerpc/fsl_booke/32, as a security >> feature that deters exploit attempts relying on knowledge of the location >> of kernel internals. >> >> Since CONFIG_RELOCATABLE has already supported, what we need to do is >> map or copy kernel to a proper place and relocate. Freescale Book-E >> parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1 >> entries are not suitable to map the kernel directly in a randomized >> region, so we chose to copy the kernel to a proper place and restart to >> relocate. >> >> Entropy is derived from the banner and timer base, which will change >> every >> build and boot. This not so much safe so additionally the bootloader may >> pass entropy via the /chosen/kaslr-seed node in device tree. >> >> We will use the first 512M of the low memory to randomize the kernel >> image. The memory will be split in 64M zones. We will use the lower 8 >> bit of the entropy to decide the index of the 64M zone. Then we chose a >> 16K aligned offset inside the 64M zone to put the kernel in. >> >>      KERNELBASE >> >>          |-->   64M   <--| >>          |               | >>          +---------------+    +----------------+---------------+ >>          |               |....|    |kernel|    |               | >>          +---------------+    +----------------+---------------+ >>          |                         | >>          |----->   offset    <-----| >> >>                                kernstart_virt_addr >> >> We also check if we will overlap with some areas like the dtb area, the >> initrd area or the crashkernel area. If we cannot find a proper area, >> kaslr will be disabled and boot from the original kernel. >> >> Changes since v5: >>   - Rename M_IF_NEEDED to MAS2_M_IF_NEEDED >>   - Define some global variable as __ro_after_init >>   - Replace kimage_vaddr with kernstart_virt_addr >>   - Depend on RELOCATABLE, not select it >>   - Modify the comment block below the SPDX tag >>   - Remove some useless headers in kaslr_booke.c and move is_second_reloc >>     declarationto mmu_decl.h >>   - Remove DBG() and use pr_debug() and rewrite comment above >> get_boot_seed(). >>   - Add a patch to document the KASLR implementation. >>   - Split a patch from patch #10 which exports kaslr offset in >> VMCOREINFO ELF notes. >>   - Remove extra logic around finding nokaslr string in cmdline. >>   - Make regions static global and __initdata >> >> Changes since v4: >>   - Add Reviewed-by tag from Christophe >>   - Remove an unnecessary cast >>   - Remove unnecessary parenthesis >>   - Fix checkpatch warning >> >> Changes since v3: >>   - Add Reviewed-by and Tested-by tag from Diana >>   - Change the comment in fsl_booke_entry_mapping.S to be consistent >>     with the new code. >> >> Changes since v2: >>   - Remove unnecessary #ifdef >>   - Use SZ_64M instead of0x4000000 >>   - Call early_init_dt_scan_chosen() to init boot_command_line >>   - Rename kaslr_second_init() to kaslr_late_init() >> >> Changes since v1: >>   - Remove some useless 'extern' keyword. >>   - Replace EXPORT_SYMBOL with EXPORT_SYMBOL_GPL >>   - Improve some assembly code >>   - Use memzero_explicit instead of memset >>   - Use boot_command_line and remove early_command_line >>   - Do not print kaslr offset if kaslr is disabled >> >> Jason Yan (12): >>    powerpc: unify definition of M_IF_NEEDED >>    powerpc: move memstart_addr and kernstart_addr to init-common.c >>    powerpc: introduce kernstart_virt_addr to store the kernel base >>    powerpc/fsl_booke/32: introduce create_tlb_entry() helper >>    powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper >>    powerpc/fsl_booke/32: implement KASLR infrastructure >>    powerpc/fsl_booke/32: randomize the kernel image offset >>    powerpc/fsl_booke/kaslr: clear the original kernel if randomized >>    powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter >>    powerpc/fsl_booke/kaslr: dump out kernel offset information on panic >>    powerpc/fsl_booke/kaslr: export offset in VMCOREINFO ELF notes >>    powerpc/fsl_booke/32: Document KASLR implementation >> >>   Documentation/powerpc/kaslr-booke32.rst       |  42 ++ >>   arch/powerpc/Kconfig                          |  11 + >>   arch/powerpc/include/asm/nohash/mmu-book3e.h  |  10 + >>   arch/powerpc/include/asm/page.h               |   7 + >>   arch/powerpc/kernel/Makefile                  |   1 + >>   arch/powerpc/kernel/early_32.c                |   2 +- >>   arch/powerpc/kernel/exceptions-64e.S          |  12 +- >>   arch/powerpc/kernel/fsl_booke_entry_mapping.S |  27 +- >>   arch/powerpc/kernel/head_fsl_booke.S          |  55 ++- >>   arch/powerpc/kernel/kaslr_booke.c             | 393 ++++++++++++++++++ >>   arch/powerpc/kernel/machine_kexec.c           |   1 + >>   arch/powerpc/kernel/misc_64.S                 |   7 +- >>   arch/powerpc/kernel/setup-common.c            |  20 + >>   arch/powerpc/mm/init-common.c                 |   7 + >>   arch/powerpc/mm/init_32.c                     |   5 - >>   arch/powerpc/mm/init_64.c                     |   5 - >>   arch/powerpc/mm/mmu_decl.h                    |  11 + >>   arch/powerpc/mm/nohash/fsl_booke.c            |   8 +- >>   18 files changed, 572 insertions(+), 52 deletions(-) >>   create mode 100644 Documentation/powerpc/kaslr-booke32.rst >>   create mode 100644 arch/powerpc/kernel/kaslr_booke.c >>