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=-2.2 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 0A2B5C3F2CE for ; Thu, 5 Mar 2020 03:22:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D6543208C3 for ; Thu, 5 Mar 2020 03:22:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725912AbgCEDW1 (ORCPT ); Wed, 4 Mar 2020 22:22:27 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:11145 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725797AbgCEDW1 (ORCPT ); Wed, 4 Mar 2020 22:22:27 -0500 Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 6A888FD62758167E30E6; Thu, 5 Mar 2020 11:22:25 +0800 (CST) Received: from [127.0.0.1] (10.173.221.195) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.439.0; Thu, 5 Mar 2020 11:22:17 +0800 Subject: Re: [PATCH v3 0/6] implement KASLR for powerpc/fsl_booke/64 To: Scott Wood , Daniel Axtens , , , , , , , , , CC: , References: <20200206025825.22934-1-yanaijie@huawei.com> <87tv3drf79.fsf@dja-thinkpad.axtens.net> From: Jason Yan Message-ID: <473e276e-ed72-b75b-9797-7845ee27db88@huawei.com> Date: Thu, 5 Mar 2020 11:22:16 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.4.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.173.221.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2020/3/5 5:21, Scott Wood 写道: > On Wed, 2020-02-26 at 18:16 +1100, Daniel Axtens wrote: >> Hi Jason, >> >>> This is a try to implement KASLR for Freescale BookE64 which is based on >>> my earlier implementation for Freescale BookE32: >>> https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=131718 >>> >>> The implementation for Freescale BookE64 is similar as BookE32. One >>> difference is that Freescale BookE64 set up a TLB mapping of 1G during >>> booting. Another difference is that ppc64 needs the kernel to be >>> 64K-aligned. So we can randomize the kernel in this 1G mapping and make >>> it 64K-aligned. This can save some code to creat another TLB map at >>> early boot. The disadvantage is that we only have about 1G/64K = 16384 >>> slots to put the kernel in. >>> >>> KERNELBASE >>> >>> 64K |--> kernel <--| >>> | | | >>> +--+--+--+ +--+--+--+--+--+--+--+--+--+ +--+--+ >>> | | | |....| | | | | | | | | |....| | | >>> +--+--+--+ +--+--+--+--+--+--+--+--+--+ +--+--+ >>> | | 1G >>> |-----> offset <-----| >>> >>> kernstart_virt_addr >>> >>> I'm not sure if the slot numbers is enough or the design has any >>> defects. If you have some better ideas, I would be happy to hear that. >>> >>> Thank you all. >>> >> >> Are you making any attempt to hide kernel address leaks in this series? >> I've just been looking at the stackdump code just now, and it directly >> prints link registers and stack pointers, which is probably enough to >> determine the kernel base address: >> >> SPs: LRs: %pS pointer >> [ 0.424506] [c0000000de403970] [c000000001fc0458] dump_stack+0xfc/0x154 >> (unreliable) >> [ 0.424593] [c0000000de4039c0] [c000000000267eec] panic+0x258/0x5ac >> [ 0.424659] [c0000000de403a60] [c0000000024d7a00] >> mount_block_root+0x634/0x7c0 >> [ 0.424734] [c0000000de403be0] [c0000000024d8100] >> prepare_namespace+0x1ec/0x23c >> [ 0.424811] [c0000000de403c60] [c0000000024d7010] >> kernel_init_freeable+0x804/0x880 >> >> git grep \\\"REG\\\" arch/powerpc shows a few other uses like this, all >> in process.c or in xmon. >> >> Maybe replacing the REG format string in KASLR mode would be sufficient? > > Whatever we decide to do here, it's not book3e-specific so it should be > considered separately from these patches. > OK, I will continue to work with this series. > -Scott > > > > . > 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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 52204C3F2CE for ; Thu, 5 Mar 2020 03:24:11 +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 F309A2070E for ; Thu, 5 Mar 2020 03:24:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F309A2070E 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 lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48Xx1N4vYKzDqmh for ; Thu, 5 Mar 2020 14:24:08 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=huawei.com (client-ip=45.249.212.190; 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 (szxga04-in.huawei.com [45.249.212.190]) (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 48XwzZ3TT9zDqlL for ; Thu, 5 Mar 2020 14:22:34 +1100 (AEDT) Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 6A888FD62758167E30E6; Thu, 5 Mar 2020 11:22:25 +0800 (CST) Received: from [127.0.0.1] (10.173.221.195) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.439.0; Thu, 5 Mar 2020 11:22:17 +0800 Subject: Re: [PATCH v3 0/6] implement KASLR for powerpc/fsl_booke/64 To: Scott Wood , Daniel Axtens , , , , , , , , , References: <20200206025825.22934-1-yanaijie@huawei.com> <87tv3drf79.fsf@dja-thinkpad.axtens.net> From: Jason Yan Message-ID: <473e276e-ed72-b75b-9797-7845ee27db88@huawei.com> Date: Thu, 5 Mar 2020 11:22:16 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.4.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.173.221.195] 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: linux-kernel@vger.kernel.org, zhaohongjiang@huawei.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 在 2020/3/5 5:21, Scott Wood 写道: > On Wed, 2020-02-26 at 18:16 +1100, Daniel Axtens wrote: >> Hi Jason, >> >>> This is a try to implement KASLR for Freescale BookE64 which is based on >>> my earlier implementation for Freescale BookE32: >>> https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=131718 >>> >>> The implementation for Freescale BookE64 is similar as BookE32. One >>> difference is that Freescale BookE64 set up a TLB mapping of 1G during >>> booting. Another difference is that ppc64 needs the kernel to be >>> 64K-aligned. So we can randomize the kernel in this 1G mapping and make >>> it 64K-aligned. This can save some code to creat another TLB map at >>> early boot. The disadvantage is that we only have about 1G/64K = 16384 >>> slots to put the kernel in. >>> >>> KERNELBASE >>> >>> 64K |--> kernel <--| >>> | | | >>> +--+--+--+ +--+--+--+--+--+--+--+--+--+ +--+--+ >>> | | | |....| | | | | | | | | |....| | | >>> +--+--+--+ +--+--+--+--+--+--+--+--+--+ +--+--+ >>> | | 1G >>> |-----> offset <-----| >>> >>> kernstart_virt_addr >>> >>> I'm not sure if the slot numbers is enough or the design has any >>> defects. If you have some better ideas, I would be happy to hear that. >>> >>> Thank you all. >>> >> >> Are you making any attempt to hide kernel address leaks in this series? >> I've just been looking at the stackdump code just now, and it directly >> prints link registers and stack pointers, which is probably enough to >> determine the kernel base address: >> >> SPs: LRs: %pS pointer >> [ 0.424506] [c0000000de403970] [c000000001fc0458] dump_stack+0xfc/0x154 >> (unreliable) >> [ 0.424593] [c0000000de4039c0] [c000000000267eec] panic+0x258/0x5ac >> [ 0.424659] [c0000000de403a60] [c0000000024d7a00] >> mount_block_root+0x634/0x7c0 >> [ 0.424734] [c0000000de403be0] [c0000000024d8100] >> prepare_namespace+0x1ec/0x23c >> [ 0.424811] [c0000000de403c60] [c0000000024d7010] >> kernel_init_freeable+0x804/0x880 >> >> git grep \\\"REG\\\" arch/powerpc shows a few other uses like this, all >> in process.c or in xmon. >> >> Maybe replacing the REG format string in KASLR mode would be sufficient? > > Whatever we decide to do here, it's not book3e-specific so it should be > considered separately from these patches. > OK, I will continue to work with this series. > -Scott > > > > . >