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 F20D9C63703 for ; Wed, 7 Dec 2022 23:22:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 913E68E0003; Wed, 7 Dec 2022 18:22:11 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8C4DB8E0001; Wed, 7 Dec 2022 18:22:11 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7659E8E0003; Wed, 7 Dec 2022 18:22:11 -0500 (EST) 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 6779C8E0001 for ; Wed, 7 Dec 2022 18:22:11 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 2CBF2120DA7 for ; Wed, 7 Dec 2022 23:22:11 +0000 (UTC) X-FDA: 80217085662.01.498D15B Received: from NAM04-MW2-obe.outbound.protection.outlook.com (mail-mw2nam04on2067.outbound.protection.outlook.com [40.107.101.67]) by imf07.hostedemail.com (Postfix) with ESMTP id 4389240013 for ; Wed, 7 Dec 2022 23:22:07 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=fQ6fLOYy; arc=pass ("microsoft.com:s=arcselector9901:i=1"); spf=pass (imf07.hostedemail.com: domain of jhubbard@nvidia.com designates 40.107.101.67 as permitted sender) smtp.mailfrom=jhubbard@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1670455328; 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:dkim-signature; bh=C29I3T0jqHheuV4HrYZSI6K9okbVjEM9o2GBycy9BZA=; b=c8FmCEwX2VGv/tmNDf+Yynegj8aNju+9xOwE85DLJFf5Jft+jNN9wr8wGsgaPIBmyv8mAE pfEC47cQPjGnc0pWT+0H9KSDHIpXQ61KPqPGajUzJhLwGk2UND0i1xn20oaDBAJocwwGIh kyqaeric6PkRhV2a5OxGLlu5kjbqqlk= ARC-Authentication-Results: i=2; imf07.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=fQ6fLOYy; arc=pass ("microsoft.com:s=arcselector9901:i=1"); spf=pass (imf07.hostedemail.com: domain of jhubbard@nvidia.com designates 40.107.101.67 as permitted sender) smtp.mailfrom=jhubbard@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1670455328; a=rsa-sha256; cv=pass; b=bLpPXsV6S251gsiyaD/GEOCBdkD25iCzCxWHAKi03bvAUTgTmATQkopz2Npy6drl1bccXV vE4fNGcKrB+p5IkgCm7aCutjdxVs0KSSuQk97z4PBEPdUwUzvsiRBCjc6CFS2SoqyuwC1p NeO3mBArlwk14+1lm5ruXjDTRu6nPqo= ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=i5Lno9wDzeJ9I9HNz3/QN8/1oQ2ubbiTMV5AJGBhjGi9mAa1JrIUoazJ+AYDIlOsI23EFg89Jt50nfRMgPBhwfP6LV3wjyNftAhL0jPXe+qbYzQpR7Q4oMcLjTZvp8//1gSHIaT3WFp64KR9l44fzrFi7DXTala7B3gU9iXDNw0sgkAieNi/4MjAUW2rGrwn18EDOKmt4fKjx9HFcIuaQ5GnpN4HYfrA9RBSWkIT09DZFwrOMbNqMNA0mjIYnyz2qjdQAexeNXqoKsvuSIDKBk5rdt8YiYH6MdRVs9n/QOwwMoXAAKxcGfoE5B9Rf2Ip6D9+33yg60H9yOGZp6V10A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=C29I3T0jqHheuV4HrYZSI6K9okbVjEM9o2GBycy9BZA=; b=OcNWbEDuWlOjdYBpNcisfAuJmFWGacTDIBa+OOzY84sfeB3nsFrtoil8rGEncnrx7sSWGI0rikdo/8P9/n+XRBa7EpS65mZSKDQnnyNPLtgSnNbQjR0Tlu6hq6nj5mIvlGQ0abu3ifsd4Js15ce9DAO/1XIyNwaoeQBDPhGRzOL7RBr0gjelNzI7q/L15/GC9TrI4IRgU2rwms10m/eroixNI98eaP2vso1kQ3Sr5wTUZFDaEcmYDcwaIKTFHieQzA2Dybyie2IGOvwfwP4dEGEwmSb3glaI/odSglxLb7nkBPu2XT8VdIWgMp4SEmBe3VzGy+ECtGVejsewHlJ03w== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 216.228.117.161) smtp.rcpttodomain=redhat.com smtp.mailfrom=nvidia.com; dmarc=pass (p=reject sp=reject pct=100) action=none header.from=nvidia.com; dkim=none (message not signed); arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=C29I3T0jqHheuV4HrYZSI6K9okbVjEM9o2GBycy9BZA=; b=fQ6fLOYyQZP/r9d2/VkCl4GQhlc7kdQke66QexcLWqzwGUS6Lmph//m51lg+ufmudNc4pqp2DPx4UIrCg2x3ow7nxbs65C9LCWG8/MhuKaNSxSGdFXoaQP1/vJJhRyaQvV0BVrG+VuXN4sQr0T9IJCYWfJDeubD3NO8rWYYVtOnR4p3EdEYz1C1vyyOJKJyqCUC98D8bKs7YfhSvHx1MSqhvjNvPLSSYrabOWCinbbH3FrFxPPC/VGPPuiiBjuA8ln1g9NKolMak0rAn3ZjaZEcegahJMgB4AsDrZeCXMoy1wMx2HV5Q71ov2DcWqt8gO/FGk+l3Ui3o+ygWraty/Q== Received: from CY5PR17CA0047.namprd17.prod.outlook.com (2603:10b6:930:12::22) by LV2PR12MB5751.namprd12.prod.outlook.com (2603:10b6:408:17d::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5880.14; Wed, 7 Dec 2022 23:22:05 +0000 Received: from CY4PEPF0000C96F.namprd02.prod.outlook.com (2603:10b6:930:12:cafe::e5) by CY5PR17CA0047.outlook.office365.com (2603:10b6:930:12::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5880.8 via Frontend Transport; Wed, 7 Dec 2022 23:22:05 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 216.228.117.161) smtp.mailfrom=nvidia.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=nvidia.com; Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates 216.228.117.161 as permitted sender) receiver=protection.outlook.com; client-ip=216.228.117.161; helo=mail.nvidia.com; pr=C Received: from mail.nvidia.com (216.228.117.161) by CY4PEPF0000C96F.mail.protection.outlook.com (10.167.242.7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5880.8 via Frontend Transport; Wed, 7 Dec 2022 23:22:05 +0000 Received: from rnnvmail201.nvidia.com (10.129.68.8) by mail.nvidia.com (10.129.200.67) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.36; Wed, 7 Dec 2022 15:21:57 -0800 Received: from [10.110.48.28] (10.126.231.37) by rnnvmail201.nvidia.com (10.129.68.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.36; Wed, 7 Dec 2022 15:21:56 -0800 Message-ID: <4daab76b-aa00-dbb2-3761-d782b00fab72@nvidia.com> Date: Wed, 7 Dec 2022 15:21:56 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.1 Subject: Re: [PATCH v2 06/10] mm/hugetlb: Make hugetlb_follow_page_mask() safe to pmd unshare Content-Language: en-US To: Peter Xu , , CC: Muchun Song , Andrea Arcangeli , James Houghton , Jann Horn , Rik van Riel , Miaohe Lin , Andrew Morton , "Mike Kravetz" , David Hildenbrand , Nadav Amit References: <20221207203034.650899-1-peterx@redhat.com> <20221207203034.650899-7-peterx@redhat.com> From: John Hubbard In-Reply-To: <20221207203034.650899-7-peterx@redhat.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.126.231.37] X-ClientProxiedBy: rnnvmail203.nvidia.com (10.129.68.9) To rnnvmail201.nvidia.com (10.129.68.8) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CY4PEPF0000C96F:EE_|LV2PR12MB5751:EE_ X-MS-Office365-Filtering-Correlation-Id: 8f6a7a9d-e774-4c76-ad35-08dad8a9da7d X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: kWogc0GJc6tTYR2iesSfhR8pPn3hJmCeEAg+d3iaciUXe5eGk5dAw6AX1OtVMsnzrvA6i726UZfXBXxN85Eyx0wMy3LeXVt/tsxDtQfYjdRLYX8nSa4o/0B1IigsJweU5A0Vz+ztj1mdjaO4gg+x3az3Qcx9WzLZDqlESaP8NqmociR6zL5JboX64vgwbbzf983X73wGYJXwfscCn6oWe/h6y+P+ep6fK2m1DbHApavohycUkyJHff08a8QrMVCNr8S0MB3iRwiHeINKwYNBASbyg7soUEQMQ/xaESp+BwGtnNyNV1jjK68570CQ+j63z67nhZHFJSZ7CKmMwjqG4QIVOAasoVjzhOSlGcuQnuhgu3UaH2OFZSgwNEW3laV4sxXXJFEGrCAy/y1ZEB5U+9gYnNoHDYOMjYuhTDAEBAXgN3zawNlig321tecQ1DJ3Cwu4gatR47f2eI8Br7S5jFWPs4ACMkikfXIcnitVjB1mc+cewXtx3+B+3h6Q7PyTLdamUftnZj0l3AStM6/8Fbzmi0+ukzWc7ZLYzRftQ+nwtz0Z+91+27xpxj1KQuBwvj6J1ASUflDqWCvlCIbNNeHZ4qtu6P1q7fC5ewU1vHPcvwZIYzzwhiB9dCM3byq7N9xzFYr+lUv0S62Dzg+ri23MHY5Sp2OFBVzi8K5Lkl5xvCXZk5WOu6Oe5Nllm+9thrTBhLzlO4HmCIHhnBbWfXUHguR9dKC7HneAeVOdwie7MXBs5OrkjM/s9TTCEhiH X-Forefront-Antispam-Report: CIP:216.228.117.161;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:dc6edge2.nvidia.com;CAT:NONE;SFS:(13230022)(4636009)(39860400002)(136003)(346002)(376002)(396003)(451199015)(40470700004)(36840700001)(46966006)(2906002)(478600001)(82740400003)(40460700003)(41300700001)(7416002)(4326008)(8676002)(31696002)(5660300002)(86362001)(40480700001)(8936002)(426003)(70206006)(70586007)(31686004)(36756003)(54906003)(47076005)(7636003)(356005)(186003)(26005)(16526019)(110136005)(336012)(82310400005)(2616005)(83380400001)(316002)(16576012)(36860700001)(53546011)(2101003)(43740500002);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Dec 2022 23:22:05.1682 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 8f6a7a9d-e774-4c76-ad35-08dad8a9da7d X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.161];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: CY4PEPF0000C96F.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV2PR12MB5751 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 4389240013 X-Stat-Signature: d8ree46ejpxxy4zzkuwi9zqjticwpmyh X-Rspam-User: X-HE-Tag: 1670455327-39002 X-HE-Meta: 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 ULO+biGF REVgkEl1YIBuqh1afvl4vplAnU8mR1q/Xq7NM0vx72ZNah5NCyPa59+2BNZyswNFiaEhCsCUZSeZ8Xv+81vOhRqWkuAahf5sDTkSR 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 12/7/22 12:30, Peter Xu wrote: > Since hugetlb_follow_page_mask() walks the pgtable, it needs the vma lock > to make sure the pgtable page will not be freed concurrently. > > Acked-by: David Hildenbrand > Reviewed-by: Mike Kravetz > Signed-off-by: Peter Xu > --- > mm/hugetlb.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) Reviewed-by: John Hubbard thanks, -- John Hubbard NVIDIA > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 49f73677a418..3fbbd599d015 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -6226,9 +6226,10 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma, > if (WARN_ON_ONCE(flags & FOLL_PIN)) > return NULL; > > + hugetlb_vma_lock_read(vma); > pte = huge_pte_offset(mm, haddr, huge_page_size(h)); > if (!pte) > - return NULL; > + goto out_unlock; > > ptl = huge_pte_lock(h, mm, pte); > entry = huge_ptep_get(pte); > @@ -6251,6 +6252,8 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma, > } > out: > spin_unlock(ptl); > +out_unlock: > + hugetlb_vma_unlock_read(vma); > return page; > } >