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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 555A2C07E9B for ; Mon, 19 Jul 2021 12:19:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 27B8261181 for ; Mon, 19 Jul 2021 12:19:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236615AbhGSLih (ORCPT ); Mon, 19 Jul 2021 07:38:37 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:11450 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231290AbhGSLig (ORCPT ); Mon, 19 Jul 2021 07:38:36 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4GT15k09Z7zcg7Z; Mon, 19 Jul 2021 20:15:54 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 19 Jul 2021 20:19:15 +0800 Received: from [10.174.177.243] (10.174.177.243) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 19 Jul 2021 20:19:14 +0800 Subject: Re: [PATCH v3 0/6] ARM: mm: cleanup page fault and fix pxn process issue To: Russell King , CC: Catalin Marinas , , Andrew Morton , Jungseung Lee , Will Deacon References: <20210610123556.171328-1-wangkefeng.wang@huawei.com> From: Kefeng Wang Message-ID: Date: Mon, 19 Jul 2021 20:19:14 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20210610123556.171328-1-wangkefeng.wang@huawei.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Russell,  kindly ping after 5.14-rc2, any comments, thanks. On 2021/6/10 20:35, Kefeng Wang wrote: > The patchset cleanup ARM page fault handle to improve readability, > fix the page table entries printing and fix infinite loop in the > page fault handler when user code execution with privilege mode if > ARM_LPAE enabled. > > echo EXEC_USERSPACE > /sys/kernel/debug/provoke-crash/DIRECT > > Before: > ------- > lkdtm: Performing direct entry EXEC_USERSPACE > lkdtm: attempting ok execution at c0717674 > lkdtm: attempting bad execution at b6fd6000 > rcu: INFO: rcu_sched self-detected stall on CPU > rcu: 1-....: (2100 ticks this GP) idle=7e2/1/0x40000002 softirq=136/136 fqs=1050 > (t=2101 jiffies g=-1027 q=16) > NMI backtrace for cpu 1 > CPU: 1 PID: 57 Comm: sh Not tainted 5.13.0-rc4 #126 > ... > r9:c1f04000 r8:c0e04cc8 r7:c1f05cbc r6:ffffffff r5:60000113 r4:c03724f8 > [] (handle_mm_fault) from [] (do_page_fault+0x1a0/0x3d8) > r10:c180ec48 r9:c11b1aa0 r8:c11b1ac0 r7:8000020f r6:b6fd6000 r5:c180ec00 > r4:c1f05df8 > [] (do_page_fault) from [] (do_PrefetchAbort+0x40/0x94) > r10:0000000f r9:c1f04000 r8:c1f05df8 r7:b6fd6000 r6:c0215154 r5:0000020f > r4:c0e09b18 > [] (do_PrefetchAbort) from [] (__pabt_svc+0x50/0x80) > Exception stack(0xc1f05df8 to 0xc1f05e40) > 5de0: 0000002b 2e34f000 > 5e00: 3ee77213 3ee77213 b6fd6000 c0b51020 c140d000 c0a4b5dc 0000000f c1f05f58 > 5e20: 0000000f c1f05e64 c1f05d88 c1f05e48 c0717a6c b6fd6000 60000013 ffffffff > r8:0000000f r7:c1f05e2c r6:ffffffff r5:60000013 r4:b6fd6000 > [] (lkdtm_EXEC_USERSPACE) from [] (lkdtm_do_action+0x48/0x4c) > r4:00000027 > ... > > > After: > ------- > lkdtm: Performing direct entry EXEC_USERSPACE > lkdtm: attempting ok execution at c07176d4 > lkdtm: attempting bad execution at b6f57000 > 8<--- cut here --- > Unable to handle kernel execution of memory at virtual address b6f57000 > pgd = 81e20f00 > [b6f57000] *pgd=81e23003, *pmd=13ee9c003 > Internal error: Oops: 8000020f [#1] SMP ARM > Modules linked in: > CPU: 0 PID: 57 Comm: sh Not tainted 5.13.0-rc4+ #127 > Hardware name: ARM-Versatile Express > PC is at 0xb6f57000 > LR is at lkdtm_EXEC_USERSPACE+0xc4/0xd4 > pc : [] lr : [] psr: 60000013 > sp : c1f3de48 ip : c1f3dd88 fp : c1f3de64 > r10: 0000000f r9 : c1f3df58 r8 : 0000000f > r7 : c0a4b5dc r6 : c1f1d000 r5 : c0b51070 r4 :b6f57000 > r3 : 7e62f7da r2 : 7e62f7da r1 : 2e330000 r0 :0000002b > Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user > ... > > v3: > - drop the fix about page table printing > - kill page table base print instead of printing the physical address > - only die when permission fault both kernel-mode and user code execution > with privilege mode > - drop LPAE specific > > v2: > - split patch into smaller changes suggested by Russell > - fix page table printing in show_pte() > - add new die_kernel_fault() helper > - report "execution of user memory" when user code execution with > privilege mode > > > Kefeng Wang (6): > ARM: mm: Rafactor the __do_page_fault() > ARM: mm: Kill task_struct argument for __do_page_fault() > ARM: mm: Cleanup access_error() > ARM: mm: Kill page table base print in show_pte() > ARM: mm: Provide die_kernel_fault() helper > ARM: mm: Fix PXN process with LPAE feature > > arch/arm/mm/fault.c | 119 +++++++++++++++++++++++--------------------- > arch/arm/mm/fault.h | 4 ++ > 2 files changed, 67 insertions(+), 56 deletions(-) >