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 F2C0EC43334 for ; Thu, 14 Jul 2022 09:59:59 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5CA9D94019C; Thu, 14 Jul 2022 05:59:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 578CC940134; Thu, 14 Jul 2022 05:59:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4682D94019C; Thu, 14 Jul 2022 05:59:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 387BD940134 for ; Thu, 14 Jul 2022 05:59:59 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay11.hostedemail.com (Postfix) with ESMTP id 03D5981238 for ; Thu, 14 Jul 2022 09:59:58 +0000 (UTC) X-FDA: 79685259318.21.02FEE87 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf09.hostedemail.com (Postfix) with ESMTP id 59BD7140080 for ; Thu, 14 Jul 2022 09:59:58 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4Lk8zd3qkgzhZ0n; Thu, 14 Jul 2022 17:57:17 +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, 14 Jul 2022 17:59:53 +0800 Subject: Re: [PATCH] mm/hugetlb: avoid corrupting page->mapping in hugetlb_mcopy_atomic_pte To: Andrew Morton CC: , , , , Axel Rasmussen , Peter Xu References: <20220712130542.18836-1-linmiaohe@huawei.com> <20220713102357.8328614813db01b569650ffd@linux-foundation.org> From: Miaohe Lin Message-ID: Date: Thu, 14 Jul 2022 17:59:53 +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: <20220713102357.8328614813db01b569650ffd@linux-foundation.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.76] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1657792798; a=rsa-sha256; cv=none; b=8PKNe0bYYp5HjJWo+Hm13FtrxPoVcm7z5Qwm3lcsU6ay+TXfdmuZhjX3ecXpqsTcVzd5SH kDLZLkeyCkL4YtOdFu+7ie1bunJaY4r/Ad/XSser8ildbUc8bdn2NVogSDI2S7cX5LyByl 6EogJTR56vkgBPESBZMAalojpXpkCIM= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=none; spf=pass (imf09.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1657792798; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=35H1bx+e8I3WUIJdZ19+SXAsJo312fctiFN9YESG+GU=; b=0PBFjfvrf54Z568pPRuCydlmmfeVItx791LT9PLn+AUZ43zZsU60NE35ZPD2xUDgFkyI6v i8PQSSAJj6CwxUTqILYhT5y6brNFaPaywpHH4cmF+DK5kj1KppTe3oRXAt0P5U0ifOkt8P dJffTAwLbxdRBftkxg8KcqN3fMB+H/w= X-Rspamd-Queue-Id: 59BD7140080 Authentication-Results: imf09.hostedemail.com; dkim=none; spf=pass (imf09.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-Rspamd-Server: rspam02 X-Rspam-User: X-Stat-Signature: ndjsyjo18ej976o8btd6jg89pxa9d91t X-HE-Tag: 1657792798-979369 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 2022/7/14 1:23, Andrew Morton wrote: > On Tue, 12 Jul 2022 21:05:42 +0800 Miaohe Lin wrote: > >> In MCOPY_ATOMIC_CONTINUE case with a non-shared VMA, pages in the page >> cache are installed in the ptes. But hugepage_add_new_anon_rmap is called >> for them mistakenly because they're not vm_shared. This will corrupt the >> page->mapping used by page cache code. > > Well that sounds bad. And theories on why this has gone unnoticed for > over a year? I assume this doesn't have coverage in our selftests? As discussed in another thread, when minor fault handling is proposed, only VM_SHARED vma is expected to be supported. And the test case is also missing. Thanks. > >> --- a/mm/hugetlb.c >> +++ b/mm/hugetlb.c >> @@ -6038,7 +6038,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, >> if (!huge_pte_none_mostly(huge_ptep_get(dst_pte))) >> goto out_release_unlock; >> >> - if (vm_shared) { >> + if (page_in_pagecache) { >> page_dup_file_rmap(page, true); >> } else { >> ClearHPageRestoreReserve(page); >> -- >> 2.23.0 > . >