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 1C586C77B73 for ; Mon, 22 May 2023 01:26:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229937AbjEVB04 (ORCPT ); Sun, 21 May 2023 21:26:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229550AbjEVB0z (ORCPT ); Sun, 21 May 2023 21:26:55 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37991C1; Sun, 21 May 2023 18:26:54 -0700 (PDT) Received: from dggpemm500001.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4QPfs215rWzLmGq; Mon, 22 May 2023 09:25:26 +0800 (CST) 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 15.1.2507.23; Mon, 22 May 2023 09:26:51 +0800 Message-ID: <75d8452c-695b-b22a-30d0-15302cd072ef@huawei.com> Date: Mon, 22 May 2023 09:26:50 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.10.1 Subject: Re: [PATCH] x86/mce: set MCE_IN_KERNEL_COPYIN for all MC-Safe Copy Content-Language: en-US To: "Luck, Tony" , Borislav Petkov , Naoya Horiguchi CC: Thomas Gleixner , Ingo Molnar , Dave Hansen , "x86@kernel.org" , Andrew Morton , "linux-edac@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "chu, jane" References: <20230508022233.13890-1-wangkefeng.wang@huawei.com> From: Kefeng Wang In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-edac@vger.kernel.org On 2023/5/20 0:17, Luck, Tony wrote: >> For now, the MCE_IN_KERNEL_COPYIN flag is only set for EX_TYPE_COPY >> and EX_TYPE_UACCESS when copy from user, and corrupted page is >> isolated in this case, for MC-safe copy, memory_failure() is not >> always called, some places, like __wp_page_copy_user, copy_subpage, >> copy_user_gigantic_page and ksm_might_need_to_copy manually call >> memory_failure_queue() to cope with such unhandled error pages, >> recently coredump hwposion recovery support[1] is asked to do the >> same thing, and there are some other already existed MC-safe copy >> scenarios, eg, nvdimm, dm-writecache, dax, which has similar issue. >> >> The best way to fix them is set MCE_IN_KERNEL_COPYIN to MCE_SAFE >> exception, then kill_me_never() will be queued to call memory_failure() >> in do_machine_check() to isolate corrupted page, which avoid calling >> memory_failure_queue() after every MC-safe copy return. >> >> [1] https://lkml.kernel.org/r/20230417045323.11054-1-wangkefeng.wang@huawei.com > > Is this patch in addition to, or instead of, the earlier core dump patch? This is an addition, in previous coredump patch, manually call memory_failure_queue() to be asked to cope with corrupted page, and it is similar to your "Copy-on-write poison recovery"[1], but after some discussion, I think we could add MCE_IN_KERNEL_COPYIN to all MC-safe copy, which will cope with corrupted page in the core do_machine_check() instead of do it one-by-one. The related patch is normal page CoW [1] huge page CoW [2] coredump [3] ksm might copy [4] [1] d302c2398ba2 ("mm, hwpoison: when copy-on-write hits poison, take page offline") a873dfe1032a ("mm, hwpoison: try to recover from copy-on write faults") [2] 1cb9dc4b475c ("mm: hwpoison: support recovery from HugePage copy-on-write faults") [3] 245f09226893 ("mm: hwpoison: coredump: support recovery from dump_user_range()") [4] 6b970599e807 ("mm: hwpoison: support recovery from ksm_might_need_to_copy()") All of them are in v6.4-rc1. Thanks. Kefeng > > I'd like to run some tests. Can you point me a the precise set of patches > that I should apply please? > > -Tony >