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 X-Spam-Level: X-Spam-Status: No, score=-11.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MSGID_FROM_MTA_HEADER,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DFD36C4743C for ; Tue, 22 Jun 2021 02:15:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 81D776124B for ; Tue, 22 Jun 2021 02:15:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 81D776124B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 138F86B0036; Mon, 21 Jun 2021 22:15:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 10FCD6B0062; Mon, 21 Jun 2021 22:15:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E7DBF6B006C; Mon, 21 Jun 2021 22:15:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0034.hostedemail.com [216.40.44.34]) by kanga.kvack.org (Postfix) with ESMTP id B25F46B0036 for ; Mon, 21 Jun 2021 22:15:06 -0400 (EDT) Received: from smtpin40.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 48883998F for ; Tue, 22 Jun 2021 02:15:06 +0000 (UTC) X-FDA: 78279742212.40.734F4C4 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf12.hostedemail.com (Postfix) with ESMTP id B02EA2BD0 for ; Tue, 22 Jun 2021 02:15:05 +0000 (UTC) Received: from pps.filterd (m0246617.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 15M2BLFU029326; Tue, 22 Jun 2021 02:14:41 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : content-transfer-encoding : content-type : mime-version; s=corp-2020-01-29; bh=VzCFuJVi1JWihrkH0U7iXWLRxWpAA8Tov5hTvpOQq40=; b=cBWE88gGjMicoakS3zQbUx3JC1NtftC/08g4iUxPW7BnrgniimNLoX53k3WF4zjeYKKb UG7jA4oypawwGFobnxrtCg+AHIcPOTXw8ZpfoKsI2bat1RVoX4+eEyfTtf2qyHUoKbSc hAFQ3wjyPMfBe+xGX9STlLxv0prhekvTXlBUehPzVRuMQL/+UPgzYLbl8wgvZXsH23dx 49awP2a1+pvzx6Q+3IapTOxq9UuAAr+bhCnl7OKIYzW1HiANFaSD/tSagyHyl5O9F6Hv Ft27Kio1ySpv/d1na+y385CDfca0UQ2FVbXeOuC9BhCEmiGWbsQFsjZbXIqIw+c21hXZ 6w== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by mx0b-00069f02.pphosted.com with ESMTP id 39aqqvsu5k-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 22 Jun 2021 02:14:41 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 15M29apP033463; Tue, 22 Jun 2021 02:14:40 GMT Received: from nam02-dm3-obe.outbound.protection.outlook.com (mail-dm3nam07lp2040.outbound.protection.outlook.com [104.47.56.40]) by aserp3030.oracle.com with ESMTP id 3996mcqnay-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 22 Jun 2021 02:14:40 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=L55F5FGlVKBzpYfa1ctEF4TNBBY/5jYFJf3gbfTs0DzamkWOVAklxOLUVLbLwN16k2fejfDHiCs7deaeW6841f9QWHy6igjzPlYD8pm6NIge9WzPjMlgostM6eEFb3lneKOrXEgFiHPh0AmGZ8b8CQ8e4LtJrCvry5hY8R3aUKl/6KICKpXwESlNAcerRsvSD+VZt4l3TexNxi97pzB+2HT/NjWwyBRLkLNOOaiyk7ArXFRVuC/7NDpV6zsSolCcOQwxfnmKTua3ONq7MWXU+r5wW/WsLIKfmpayy5XJZpIzHaHnzmJWRFRuLGlBi5Fjs/XPm6P3UquhZ4N+6HcZHA== 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-SenderADCheck; bh=VzCFuJVi1JWihrkH0U7iXWLRxWpAA8Tov5hTvpOQq40=; b=SdoexbbU5VFbkK2PzgvFt91ojiXylioT0Kkeg7MztVRkMSS46diPFLbDbJqTKd7PoHHfjtluUAEwqlAUP+oB5fgnTHwQfBLhHt4LLmxqB5WdCxEM3yC2Gy9wdYdkyxipG+LNuSzSZv0E2XTaMshCmPMB+awFEVt5Gwr+yvFwx/jApR2//WZigr6DP13YOk/9CfN/hvtDxEjODLvnTfRqQMtYZIhIFGC/Y00pT9s0EgCoT61twUYw9a+ZN3hoxjAbVoDZinyq4mZi+bfzMgSzfJJI1Z9rTZryTL7yerSpZaAcg36LvCf9Dr6D4Ioqe+kzochwVqGtsKXJP7xV8sRndw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=VzCFuJVi1JWihrkH0U7iXWLRxWpAA8Tov5hTvpOQq40=; b=etHJSFGUB1776AQb8ZIm8IF4RohsFzhhOMF3h7ddE24bOQQfbgsWbGOFfnVtDcUK6LA6HAsOM/31O4DI0PBQr5weG2O+HsolPtAXlyKXvgC8kLcLPJQtzqlUidXwD5e6fCoIsffKOVKjBYVX814OSielhGOclVRLe8pANELMWfM= Received: from BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) by BYAPR10MB2664.namprd10.prod.outlook.com (2603:10b6:a02:b7::27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4242.16; Tue, 22 Jun 2021 02:14:37 +0000 Received: from BY5PR10MB4196.namprd10.prod.outlook.com ([fe80::5d11:ae6d:24b6:e838]) by BY5PR10MB4196.namprd10.prod.outlook.com ([fe80::5d11:ae6d:24b6:e838%4]) with mapi id 15.20.4242.023; Tue, 22 Jun 2021 02:14:37 +0000 From: Mike Kravetz To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Jann Horn , Youquan Song , Andrea Arcangeli , Jan Kara , John Hubbard , "Kirill A . Shutemov" , Matthew Wilcox , Michal Hocko , Andrew Morton , Mike Kravetz Subject: [PATCH 0/2] Fix prep_compound_gigantic_page ref count adjustment Date: Mon, 21 Jun 2021 19:14:21 -0700 Message-Id: <20210622021423.154662-1-mike.kravetz@oracle.com> X-Mailer: git-send-email 2.31.1 Content-Type: text/plain X-Originating-IP: [50.38.35.18] X-ClientProxiedBy: MW4PR03CA0072.namprd03.prod.outlook.com (2603:10b6:303:b6::17) To BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from monkey.oracle.com (50.38.35.18) by MW4PR03CA0072.namprd03.prod.outlook.com (2603:10b6:303:b6::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4242.19 via Frontend Transport; Tue, 22 Jun 2021 02:14:36 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 18a62b80-8a9b-40f6-8298-08d935237c0e X-MS-TrafficTypeDiagnostic: BYAPR10MB2664: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:9508; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BY5PR10MB4196.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(376002)(396003)(136003)(39860400002)(366004)(346002)(52116002)(16526019)(186003)(66946007)(86362001)(66556008)(5660300002)(66476007)(8936002)(7696005)(2906002)(7416002)(1076003)(26005)(8676002)(36756003)(478600001)(44832011)(107886003)(38350700002)(38100700002)(54906003)(316002)(6486002)(2616005)(4326008)(83380400001)(956004)(6666004);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?jtdHyoz7oTag7daeCkJVkrgJegFGo/IMhXpMWP3HV+YmnHmI66N3arXL+Mwv?= =?us-ascii?Q?96qI0ka1at2eGJrG+i44GXR05+3PB1z1mFvkJZOmgEIgwY1mlfFT5pKvG6dN?= =?us-ascii?Q?XqVHmj4QiShSpEBmD+9TqGDLhReE0RtFz34BoVGPE/xI3HZf3oZxMR5yY/UZ?= =?us-ascii?Q?pWkWOgT6DFoQuX46jzihAR92Hq9zGDTiJnnCcUDXrDcAO+JDn2MrU5dmuJrM?= =?us-ascii?Q?/vDWrbQxl32LLePcOLm8pGI49/MA0w11oHr6KBgRepiPmUu/dZpRZjbHDFzl?= =?us-ascii?Q?nGn5SHw5WwSgyYT5vwzPZ5Tvexlw3YHhWldFCY1OD9pqGFV4IiOTegv5Z245?= =?us-ascii?Q?PS2+gBaSX/CYXfAvm0iG/adRtgEUa1MJnyhSYTqlO0IDF5yr0fgKaY7PmoCj?= =?us-ascii?Q?YC3rEwyBbpF/RVJtSUkiJHQr2zEkN8/pZKqjGJ+bC8TKUseXEG590yj6lweM?= =?us-ascii?Q?opdcq1HdCG3Zq2eGbnNpuxbnDKfzA75RiEqKUIWPBxecdcjYRf35GGKZhJrr?= =?us-ascii?Q?lyc9vF/+giYsq730kFAMZz/GLvSmpom46hcSCnZXOdrSpv6aMOONuItP86M0?= =?us-ascii?Q?iqnyHHQd5/ztxbBH2VFeWLbrRt1N5lrEJhB9zanwE3gPyY3i/XGKu7jao2UO?= =?us-ascii?Q?0w9IhUd3LJhKPdaZkhX6MdERk3iHkwTgvQN7m6qTBm0JRF9B7cAYRssCZ5cL?= =?us-ascii?Q?2qTe7jFx0N8LgOrOoCj+1EHKh6KCpoxV3lpPa2WVIlf0cx9CG4icEWS3MSSE?= =?us-ascii?Q?EVJhhbJcsgI8fy9jcjWpoVgjkY3MjN4G85cWrLtB6bSoly5L5J+6pUMRc7bB?= =?us-ascii?Q?+gcR2LVhLinq8Gpe9nd8QxTvSKDh+0T/b0ny2r1S2lKTOJsfLDpUyxlnT4GS?= =?us-ascii?Q?OssB4iDx5VAWd1LcXnjAU1O0cDTQRfIMV9kFev9hPF2SA0/0TFnTJMlyFBzy?= =?us-ascii?Q?K7C7d/fe3awah95mf++DhZQBV4nVM0XUJfVpkha5siG1xtuIbCup3iIa2nE6?= =?us-ascii?Q?bRavE2x7EWS08YRWWvBSQS1H1+YDIIzXCNFM4gRWO/iGi29R396hap02GHXQ?= =?us-ascii?Q?w96JyVPUIEt2GjgKNo2TTusNv9VDdwz0jV+1+tWxOg5uICugITq9/mwmweyG?= =?us-ascii?Q?drWVh6Se0YK5zuD81592c3E2HKMZj99b+oxvbHcTjjY4ZkVA7SyupQDLTU40?= =?us-ascii?Q?JrHN0Fjt473KPpYFWpuhWBsYi13yQIxVJNPf0qeDoCEhlqSY32G71+IDWbA3?= =?us-ascii?Q?StVyWiWX92446chwGIV/mIK093e58mpU6q4UqpokGLwml4ONeTU+Zet65txn?= =?us-ascii?Q?DFOAnoimBYgE1sFg/jYs1k91?= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 18a62b80-8a9b-40f6-8298-08d935237c0e X-MS-Exchange-CrossTenant-AuthSource: BY5PR10MB4196.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Jun 2021 02:14:37.3906 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Bn8eSXlAHtWvJ0C279iwgnUxo0txLiFyb6g5PDCwarSMDnrJRBwVYBOgEOX2zFzsdhcWcyPAk4GVh84d4x48rg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR10MB2664 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=10022 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 mlxscore=0 mlxlogscore=898 adultscore=0 phishscore=0 spamscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2106220012 X-Proofpoint-ORIG-GUID: oYkU3KXzhm4cN3k8xAyCAQ-cqeo1A_6I X-Proofpoint-GUID: oYkU3KXzhm4cN3k8xAyCAQ-cqeo1A_6I Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2020-01-29 header.b=cBWE88gG; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=etHJSFGU; spf=none (imf12.hostedemail.com: domain of mike.kravetz@oracle.com has no SPF policy when checking 205.220.165.32) smtp.mailfrom=mike.kravetz@oracle.com; dmarc=pass (policy=none) header.from=oracle.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: B02EA2BD0 X-Stat-Signature: 7wp71xyxnr5ttdhqsfea41qpbkn5p6ya X-HE-Tag: 1624328105-254576 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000452, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: These patches address the possible race between prep_compound_gigantic_pa= ge and __page_cache_add_speculative as described by Jann Horn in [1]. The first patch simply removes the unnecessary/obsolete helper routine prep_compound_huge_page to make the actual fix a little simpler. The second patch is the actual fix and has a detailed explanation in the commit message. This potential issue has existed for almost 10 years and I am unaware of anyone actually hitting the race. I did not cc stable, but would be happy to squash the patches and send to stable if anyone thinks that is a good idea. I could not think of a reliable way to recreate the issue for testing. Rather, I 'simulated errors' to exercise all the error paths. Mike Kravetz (2): hugetlb: remove prep_compound_huge_page cleanup hugetlb: address ref count racing in prep_compound_gigantic_page mm/hugetlb.c | 99 ++++++++++++++++++++++++++++++++++++------------- mm/page_alloc.c | 1 - 2 files changed, 73 insertions(+), 27 deletions(-) --=20 2.31.1