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 59ED1C77B73 for ; Wed, 24 May 2023 11:23:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233267AbjEXLXl (ORCPT ); Wed, 24 May 2023 07:23:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234708AbjEXLXk (ORCPT ); Wed, 24 May 2023 07:23:40 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3157518B; Wed, 24 May 2023 04:23:36 -0700 (PDT) Received: from dggpemm500001.china.huawei.com (unknown [172.30.72.55]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4QR80Z1wvvzLmG5; Wed, 24 May 2023 19:22:06 +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; Wed, 24 May 2023 19:23:33 +0800 Message-ID: Date: Wed, 24 May 2023 19:23:33 +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: Tony Luck , Borislav Petkov , Naoya Horiguchi CC: Thomas Gleixner , Ingo Molnar , Dave Hansen , , Andrew Morton , , , , References: <20230508022233.13890-1-wangkefeng.wang@huawei.com> From: Kefeng Wang In-Reply-To: <20230508022233.13890-1-wangkefeng.wang@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit 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-edac@vger.kernel.org Hi x86/mm maintainers, could you pick this up as it has be reviewed by Naoya and Tony, many thanks. On 2023/5/8 10:22, Kefeng Wang wrote: > Both EX_TYPE_FAULT_MCE_SAFE and EX_TYPE_DEFAULT_MCE_SAFE exception > fixup types are used to identify fixups which allow in kernel #MC > recovery, that is the Machine Check Safe Copy. > > 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 > > Signed-off-by: Kefeng Wang