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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6FDFCC433EF for ; Tue, 19 Apr 2022 12:00:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D8B778D0068; Tue, 19 Apr 2022 08:00:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D39A48D0047; Tue, 19 Apr 2022 08:00:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C023B8D0068; Tue, 19 Apr 2022 08:00:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0235.hostedemail.com [216.40.44.235]) by kanga.kvack.org (Postfix) with ESMTP id AD7A48D0047 for ; Tue, 19 Apr 2022 08:00:37 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 686E5183459DC for ; Tue, 19 Apr 2022 12:00:37 +0000 (UTC) X-FDA: 79373486514.28.8070BD2 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by imf28.hostedemail.com (Postfix) with ESMTP id 4F04DC0017 for ; Tue, 19 Apr 2022 12:00:35 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.57]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KjMhT1dWszCrBk; Tue, 19 Apr 2022 19:56:09 +0800 (CST) Received: from [10.174.177.76] (10.174.177.76) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 19 Apr 2022 20:00:32 +0800 Subject: Re: [PATCH v2] mm/swapfile: unuse_pte can map random data if swap read fails To: David Hildenbrand , CC: , , , , , , , , , , , , References: <20220416030549.60559-1-linmiaohe@huawei.com> <1b614ac3-02c0-ec66-b51a-e9b7e1a375ad@huawei.com> From: Miaohe Lin Message-ID: Date: Tue, 19 Apr 2022 20:00:32 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.76] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Authentication-Results: imf28.hostedemail.com; dkim=none; spf=pass (imf28.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-Stat-Signature: 1s5nec977qnkbxuhd6bif79q7xw9fgoe X-Rspamd-Queue-Id: 4F04DC0017 X-Rspamd-Server: rspam04 X-Rspam-User: X-HE-Tag: 1650369635-154593 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2022/4/19 19:46, David Hildenbrand wrote: ... >> Do you mean that we should set the pfn to 0 for the hwpoison marker so that we can >> distinguish swapin error case from real hwpoison case? > > I am not sure if we really have to distinguish. However, "0" seems to > make sense to indicate "this is not an actual problematic PFN, the > information is simply no longer around due to a hardware issue. > IMHO, we have to distinguish. For example, we might need to return VM_FAULT_SIGBUS instead of VM_FAULT_HWPOISON when user accesses the error page. Or should we simply return VM_FAULT_HWPOISON to simplify the handling? Thanks!