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 682CCC47404 for ; Wed, 9 Oct 2019 06:12:32 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1C56720679 for ; Wed, 9 Oct 2019 06:12:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C56720679 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46p3lx5pWJzDqJW for ; Wed, 9 Oct 2019 17:12:29 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=huawei.com (client-ip=45.249.212.32; helo=huawei.com; envelope-from=yanaijie@huawei.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from huawei.com (szxga06-in.huawei.com [45.249.212.32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46p3jy4nydzDqJk for ; Wed, 9 Oct 2019 17:10:44 +1100 (AEDT) Received: from DGGEMS414-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 67AE8BE9F0EFCB45E312; Wed, 9 Oct 2019 14:10:39 +0800 (CST) Received: from [127.0.0.1] (10.177.96.203) by DGGEMS414-HUB.china.huawei.com (10.3.19.214) with Microsoft SMTP Server id 14.3.439.0; Wed, 9 Oct 2019 14:10:29 +0800 Subject: Re: [PATCH v7 00/12] implement KASLR for powerpc/fsl_booke/32 From: Jason Yan To: , , , , , , , , , References: <20190920094546.44948-1-yanaijie@huawei.com> <9c2dd2a8-83f2-983c-383e-956e19a7803a@huawei.com> Message-ID: Date: Wed, 9 Oct 2019 14:10:27 +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: <9c2dd2a8-83f2-983c-383e-956e19a7803a@huawei.com> 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 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wangkefeng.wang@huawei.com, linux-kernel@vger.kernel.org, jingxiangfeng@huawei.com, zhaohongjiang@huawei.com, thunder.leizhen@huawei.com, yebin10@huawei.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hi Scott, Would you please take sometime to test this? Thank you so much. On 2019/9/24 13:52, Jason Yan wrote: > Hi Scott, > > Can you test v7 to see if it works to load a kernel at a non-zero address? > > Thanks, > > On 2019/9/20 17:45, 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 v6: >> - Rename create_tlb_entry() to create_kaslr_tlb_entry() >> - Remove MAS2_VAL since there is no more users. >> - Move kaslr_booke.c to arch/powerpc/mm/nohash. >> - Call flush_icache_range() after copying the kernel. >> - Warning if no kaslr-seed provided by the bootloader >> - Use the right physical address when checking if the new position >> will overlap with other regions. >> - Do not clear bss for the second pass because some global variables >> will not be initialized again >> - Use tabs instead of spaces between the mnemonic and the >> arguments(in fsl_booke_entry_mapping.S). >> >> 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_kaslr_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 | 11 +- >> arch/powerpc/include/asm/page.h | 7 + >> arch/powerpc/kernel/early_32.c | 5 +- >> arch/powerpc/kernel/exceptions-64e.S | 12 +- >> arch/powerpc/kernel/fsl_booke_entry_mapping.S | 25 +- >> arch/powerpc/kernel/head_fsl_booke.S | 61 ++- >> 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/Makefile | 1 + >> arch/powerpc/mm/nohash/fsl_booke.c | 8 +- >> arch/powerpc/mm/nohash/kaslr_booke.c | 401 ++++++++++++++++++ >> 18 files changed, 587 insertions(+), 53 deletions(-) >> create mode 100644 Documentation/powerpc/kaslr-booke32.rst >> create mode 100644 arch/powerpc/mm/nohash/kaslr_booke.c >> > > > . >