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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98160C433EF for ; Tue, 28 Jun 2022 11:17:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344781AbiF1LRZ (ORCPT ); Tue, 28 Jun 2022 07:17:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44054 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344574AbiF1LRX (ORCPT ); Tue, 28 Jun 2022 07:17:23 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F9832DA80 for ; Tue, 28 Jun 2022 04:17:19 -0700 (PDT) Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4LXMTp2KqRzkWfG; Tue, 28 Jun 2022 19:15:58 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggpemm500022.china.huawei.com (7.185.36.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 28 Jun 2022 19:17:17 +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 15.1.2375.24; Tue, 28 Jun 2022 19:17:16 +0800 Message-ID: <88e574b4-3191-8c0f-1dc3-7c54c426142c@huawei.com> Date: Tue, 28 Jun 2022 19:17:15 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH -next v6 00/10]arm64: add machine check safe support Content-Language: en-US To: Tong Tiangen , Mark Rutland , James Morse , Andrew Morton , Thomas Gleixner , "Ingo Molnar" , Borislav Petkov , Robin Murphy , Dave Hansen , "Catalin Marinas" , Will Deacon , "Alexander Viro" , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , , "H . Peter Anvin" CC: , , , , Xie XiuQi , Guohanjun References: <20220621072638.1273594-1-tongtiangen@huawei.com> From: Kefeng Wang In-Reply-To: <20220621072638.1273594-1-tongtiangen@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) 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 On 2022/6/21 15:26, Tong Tiangen wrote: > With the increase of memory capacity and density, the probability of > memory error increases. The increasing size and density of server RAM > in the data center and cloud have shown increased uncorrectable memory > errors. > > Currently, the kernel has a mechanism to recover from hardware memory > errors. This patchset provides an new recovery mechanism. > > For arm64, the hardware memory error handling is do_sea() which divided > into two cases: > 1. The user state consumed the memory errors, the solution is kill the > user process and isolate the error page. > 2. The kernel state consumed the memory errors, the solution is panic. > > For case 2, Undifferentiated panic maybe not the optimal choice, it can be > handled better, in some scenarios, we can avoid panic, such as uaccess, if the > uaccess fails due to memory error, only the user process will be affected, > kill the user process and isolate the user page with hardware memory errors > is a better choice. > > This patchset can be divided into two parts: > 1. Patch 1~6 - do some restructuring to arm64 extable. > 2. Patch 7~10 - arm64 add support for machine check safe framework, > then ,add two specific scenarios(uaccess/cow) to machine check safe. It's a good to see more RAS feature on arm64, and we do meet some panic during copy_from/to_user and CoW processing in our production, for series， Reviewed-by: Kefeng Wang > > Since V5: > 1. Add patch2/3 to add uaccess assembly helpers. > 2. Optimize the implementation logic of arm64_do_kernel_sea() in patch8. > 3. Remove kernel access fixup in patch9. > All suggestion are from Mark. > > Since V4: > 1. According Michael's suggestion, add patch5. > 2. According Mark's suggestiog, do some restructuring to arm64 > extable, then a new adaptation of machine check safe support is made based > on this. > 3. According Mark's suggestion, support machine check safe in do_mte() in > cow scene. > 4. In V4, two patches have been merged into -next, so V5 not send these > two patches. > > Since V3: > 1. According to Robin's suggestion, direct modify user_ldst and > user_ldp in asm-uaccess.h and modify mte.S. > 2. Add new macro USER_MC in asm-uaccess.h, used in copy_from_user.S > and copy_to_user.S. > 3. According to Robin's suggestion, using micro in copy_page_mc.S to > simplify code. > 4. According to KeFeng's suggestion, modify powerpc code in patch1. > 5. According to KeFeng's suggestion, modify mm/extable.c and some code > optimization. > > Since V2: > 1. According to Mark's suggestion, all uaccess can be recovered due to > memory error. > 2. Scenario pagecache reading is also supported as part of uaccess > (copy_to_user()) and duplication code problem is also solved. > Thanks for Robin's suggestion. > 3. According Mark's suggestion, update commit message of patch 2/5. > 4. According Borisllav's suggestion, update commit message of patch 1/5. > > Since V1: > 1.Consistent with PPC/x86, Using CONFIG_ARCH_HAS_COPY_MC instead of > ARM64_UCE_KERNEL_RECOVERY. > 2.Add two new scenes, cow and pagecache reading. > 3.Fix two small bug(the first two patch). > > V1 in here: > https://lore.kernel.org/lkml/20220323033705.3966643-1-tongtiangen@huawei.com/ > > Tong Tiangen (10): > arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support > arm64: asm-extable: move data fields > arm64: asm-extable: add asm uacess helpers > arm64: extable: make uaaccess helper use extable type > EX_TYPE_UACCESS_ERR_ZERO > arm64: extable: move _cond_extable to _cond_uaccess_extable > arm64: extable: cleanup redundant extable type EX_TYPE_FIXUP > Add generic fallback version of copy_mc_to_user() > arm64: add support for machine check error safe > arm64: add uaccess to machine check safe > arm64: add cow to machine check safe > > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/asm-extable.h | 84 ++++++++++++++++++------- > arch/arm64/include/asm/asm-uaccess.h | 12 ++-- > arch/arm64/include/asm/assembler.h | 8 ++- > arch/arm64/include/asm/extable.h | 1 + > arch/arm64/include/asm/mte.h | 4 ++ > arch/arm64/include/asm/page.h | 10 +++ > arch/arm64/include/asm/uaccess.h | 94 ++++++++++++++-------------- > arch/arm64/lib/Makefile | 2 + > arch/arm64/lib/copy_page_mc.S | 82 ++++++++++++++++++++++++ > arch/arm64/lib/mte.S | 19 ++++++ > arch/arm64/mm/copypage.c | 41 +++++++++--- > arch/arm64/mm/extable.c | 21 ++++++- > arch/arm64/mm/fault.c | 29 ++++++++- > arch/powerpc/include/asm/uaccess.h | 1 + > arch/x86/include/asm/uaccess.h | 1 + > include/linux/highmem.h | 8 +++ > include/linux/uaccess.h | 9 +++ > mm/memory.c | 2 +- > 19 files changed, 339 insertions(+), 90 deletions(-) > create mode 100644 arch/arm64/lib/copy_page_mc.S >