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 E3AF3C433F5 for ; Thu, 21 Apr 2022 01:50:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6C5DA6B0071; Wed, 20 Apr 2022 21:50:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 674C06B0073; Wed, 20 Apr 2022 21:50:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 53CBE6B0074; Wed, 20 Apr 2022 21:50:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.26]) by kanga.kvack.org (Postfix) with ESMTP id 41A5C6B0071 for ; Wed, 20 Apr 2022 21:50:13 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 0EF334BE for ; Thu, 21 Apr 2022 01:50:13 +0000 (UTC) X-FDA: 79379205906.16.CEAB03A Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by imf25.hostedemail.com (Postfix) with ESMTP id 2155BA0018 for ; Thu, 21 Apr 2022 01:50:09 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.56]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KkL396nGfzCrcL; Thu, 21 Apr 2022 09:45:41 +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; Thu, 21 Apr 2022 09:50:07 +0800 Subject: Re: [PATCH v2] mm/swapfile: unuse_pte can map random data if swap read fails To: Peter Xu CC: , , , , , , , , , , , , , References: <20220416030549.60559-1-linmiaohe@huawei.com> <8e01e276-c956-2486-c55f-c689f33a9106@huawei.com> From: Miaohe Lin Message-ID: <8d180899-9ae2-a38b-3642-ffd057b7acaf@huawei.com> Date: Thu, 21 Apr 2022 09:50:06 +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: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Authentication-Results: imf25.hostedemail.com; dkim=none; spf=pass (imf25.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: p4djornhdbn5hc4qo7ccwdh585zhj33q X-Rspamd-Queue-Id: 2155BA0018 X-Rspamd-Server: rspam04 X-Rspam-User: X-HE-Tag: 1650505808-670889 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 2022/4/20 21:32, Peter Xu wrote: > On Wed, Apr 20, 2022 at 02:21:27PM +0800, Miaohe Lin wrote: >> On 2022/4/20 5:36, Peter Xu wrote: >>> On Sat, Apr 16, 2022 at 11:05:49AM +0800, Miaohe Lin wrote: >>>> @@ -1797,6 +1797,17 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, >>>> goto out; >>>> } >>>> >>>> + if (unlikely(!PageUptodate(page))) { >>>> + pte_t pteval; >>>> + >>>> + dec_mm_counter(vma->vm_mm, MM_SWAPENTS); >>>> + pteval = swp_entry_to_pte(make_swapin_error_entry(page)); >>>> + set_pte_at(vma->vm_mm, addr, pte, pteval); >>>> + swap_free(entry); >>>> + ret = 0; >>>> + goto out; >>>> + } >>>> + >>>> /* See do_swap_page() */ >>>> BUG_ON(!PageAnon(page) && PageMappedToDisk(page)); >>>> BUG_ON(PageAnon(page) && PageAnonExclusive(page)); >>> >>> Totally off-topic, but.. today when I was looking at the unuse path I just >>> found that the swp bits could have got lost for either soft-dirty and >>> uffd-wp here? A quick patch attached. >> >> Am I supposed to test-and-send this patch? The patch looks good to me except the >> build error pointed out by kernel test robot. > > I was planning to post a patch after yours since they're touching the same > function, but yeah it'll be great if you could also take that over, thanks! Sure, I will take this in next version. Thanks a lot! :) >