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=-10.4 required=3.0 tests=BAYES_00, CHARSET_FARAWAY_HEADER,DKIM_INVALID,DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 D4F10C433E6 for ; Thu, 14 Jan 2021 01:49:56 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 74DC923447 for ; Thu, 14 Jan 2021 01:49:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 74DC923447 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=nec.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id DF964100F225F; Wed, 13 Jan 2021 17:49:53 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=40.107.131.74; helo=apc01-sg2-obe.outbound.protection.outlook.com; envelope-from=naoya.horiguchi@nec.com; receiver= Received: from APC01-SG2-obe.outbound.protection.outlook.com (mail-eopbgr1310074.outbound.protection.outlook.com [40.107.131.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 687FE100F225D for ; Wed, 13 Jan 2021 17:49:50 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=DfbhPR1FjSaObN3CIMqC3Uc2tHWGUFsB2jY5YoFV0hISx7/ae76TSvIpdClrXdcID60isXK/wNI0IzEPfiOOOw8hwyiY7sH6KDTgDgmIcbGo5rCpfJsF2aQqo+scYyk62/TxMOn2x7EeVJEE7JLMktO+LuLQKo/Ebs2LRCbXQ15UVtHwDGxeEVH4a79QL53C3mjClhfNQ9T+odDE7txqUBmCwx5ibCjBYn9nBwPRFWxS80ZV81F5f4P7a5nG3OpyNwbbraKLGktH2WEMiBpnJJZP20OMNfF6FDFpHVQaAGjFIjsTXvBAI4sfSowEsx0XAJdCLdp5vVq8FEIW8j+BPQ== 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=kM/q6TF+NCyW9DrUCtrprUHkZFAzrkt4+MOq23S903E=; b=V7lUTcr/zahB3zMEXSEeUNiz6jEUMneO9u/NKp5wMdmLvoKLX99FcBakwBDjx2ZrErzZHseeiYw8ywrtS1hBuiin7+EKs4ql9jn4U38Br05bjjKAAi57d09MK8DKD4l75U0K9/pPc398mTrvAvP9fPcEScgPNvOLx+Y8lp0ZYCSH/2t3mSHrpb4pnvnbU67o8tpfG9OUFjJfOAOGXRTKxyWVVpo/LZ+J3ZKYXxQsTUKf7+0pcCnPqcjroEj3JtybBqBbyRaBNMaeJkcPnjd5MvKmztdhaSLNl1AAQGfpEfzUEO61T2bRPVVid2oWANFABRqwD72EdfrHl3BtZ/NCEw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nec.com; dmarc=pass action=none header.from=nec.com; dkim=pass header.d=nec.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nec.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=kM/q6TF+NCyW9DrUCtrprUHkZFAzrkt4+MOq23S903E=; b=ddEly2VpiCCcytnJCJQChwmWSILhqevrp+roRB/eaABm8+1mHUS31JCnx00UcsYV/sG/ZX9CZBbGi7p/Wm064MUnFFs+SUJeV27vM1jTSD7IuDUJMMhb+buzLHQjq9YjCGNYgKlnbGWQFrRYrVOVDttbYCQNf6fIiiwD0jq60Gc= Received: from TY1PR01MB1852.jpnprd01.prod.outlook.com (2603:1096:403:8::12) by TY2PR01MB4812.jpnprd01.prod.outlook.com (2603:1096:404:10e::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3742.11; Thu, 14 Jan 2021 01:49:45 +0000 Received: from TY1PR01MB1852.jpnprd01.prod.outlook.com ([fe80::8453:2ddb:cf2b:d244]) by TY1PR01MB1852.jpnprd01.prod.outlook.com ([fe80::8453:2ddb:cf2b:d244%7]) with mapi id 15.20.3763.010; Thu, 14 Jan 2021 01:49:45 +0000 From: =?iso-2022-jp?B?SE9SSUdVQ0hJIE5BT1lBKBskQktZOH0hIUQ+TGkbKEIp?= To: Dan Williams Subject: Re: [PATCH v4 4/5] mm: Fix page reference leak in soft_offline_page() Thread-Topic: [PATCH v4 4/5] mm: Fix page reference leak in soft_offline_page() Thread-Index: AQHW6heInkqG7QE910OSp4LbdxOpwg== Date: Thu, 14 Jan 2021 01:49:45 +0000 Message-ID: <20210114014944.GA16873@hori.linux.bs1.fc.nec.co.jp> References: <161058499000.1840162.702316708443239771.stgit@dwillia2-desk3.amr.corp.intel.com> <161058501210.1840162.8108917599181157327.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <161058501210.1840162.8108917599181157327.stgit@dwillia2-desk3.amr.corp.intel.com> Accept-Language: ja-JP, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: intel.com; dkim=none (message not signed) header.d=none;intel.com; dmarc=none action=none header.from=nec.com; x-originating-ip: [165.225.110.205] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: db092a07-eda8-46d3-993c-08d8b82eab15 x-ms-traffictypediagnostic: TY2PR01MB4812: x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:10000; x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: dIYyUlgQFBNZf8iezHkwsu4u7yx4CiAxuPGOOl1/h7VmHAS9+xGrX5gHBAqMw7IHFO0oDv0HBpxq6c9vwaHRZ43k8v8yVITyuI6/2tYs6ukuDCQy6bimd/HdLisWCGOVB7eaD9UqkkTPyA855YcJ6n8QtCbsC17868Uc+ZBc5CfCncPujH51vtIqzaZV4/Hjz9YQnwgOWa3rXsmyfVlvyEcvcCoP2Gjs88yueJuTDv413uAcAZB0EefD1InBLoy0vrizgRYH+0Tz4ccLoIhz2Hw5wTWr7fk/6+RxIrgB3KUNs+G+f9eXbEe5KXPIHH2fp8COPHs8ZFx9bSNyCbXBa/jWhFl0EybrEj8/6pe9qT47mjusJ4Zfr7tCWpNjJ6FpLa1/oZDZ2ztrobQJSgxSQg== x-forefront-antispam-report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:TY1PR01MB1852.jpnprd01.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(376002)(136003)(396003)(366004)(39860400002)(346002)(9686003)(7416002)(6916009)(6512007)(26005)(186003)(478600001)(55236004)(64756008)(66476007)(5660300002)(66446008)(66556008)(8936002)(4326008)(33656002)(83380400001)(8676002)(6506007)(316002)(54906003)(2906002)(71200400001)(85182001)(76116006)(66946007)(86362001)(1076003)(6486002);DIR:OUT;SFP:1101; x-ms-exchange-antispam-messagedata: =?iso-2022-jp?B?OE1waGcxaEREV29leUlnRHBjcnkybnV3YncwNi9BVHNjelhCU1pMVmZ2?= =?iso-2022-jp?B?K1dIc1daUFFSaGtkdjVoMmZGWXRycDNFM0dBNnhGSDNpVDF1ZzJybFJE?= =?iso-2022-jp?B?SlQxRWZjMjROczdtLzNyeXhLTzIzOGd4Tnc2WklBQk9EZnRJN2lMUVhT?= =?iso-2022-jp?B?WkxBL1hYZklqbmpPZStWNXlUQ284N3hFT0pnSGRwbVBsdjRycmZYVmJx?= =?iso-2022-jp?B?clZDL0JnQTFseHh4ZVlENzAwenhTUU5KTmNnQitxQWV1SVYzMmluYVZW?= =?iso-2022-jp?B?TzdBc0pSUlVoOXRNTjRlOXFSckZWSDVqVHJkOXRGZW0yZGNycmZRZ1Ro?= =?iso-2022-jp?B?SUx5Tm0yUElPUUhDcnlTTmx4VFhHbTZha3dqNEoyaG1BM3VQOHhkSEpD?= =?iso-2022-jp?B?dmdIbzlQV2ZXTlViUHYzRUhHT21rNGd5YWE4RUlkTVJuakZKRVU0SnQ0?= =?iso-2022-jp?B?ZmlUQnN5QS83YzdCZ2pDZjJ0YllUZFhZNERnUU1STGN6bWRHeEprWm5G?= =?iso-2022-jp?B?dUlmZkVVa3V6dEdZaWxHekYwK21VcG1ybE5VZkZrRmp5YmcySUtFc3NM?= =?iso-2022-jp?B?bVV1NEVua3ZHVnpTNzk3VURUM0hIckdsdDhVSDBXY2NhMUs2QXVKVzBB?= =?iso-2022-jp?B?VHRycVFHY0Y0clo3bUhuNEc3bmtnclFrYUF5MVBzeFdQbTN1K1RESmhs?= =?iso-2022-jp?B?dmNUb2VDd2N5NTZkQjljbmQ0Qi8yUytsYjA4Q3o0WHhGMW1DSVJHdzMy?= =?iso-2022-jp?B?dWVhc0dKSW1QejZ3OGdteEMyL0pTd2UvM0VRbDlJSzFZYXVWRFlrSHlD?= =?iso-2022-jp?B?by8xM1pDWTlaa3BIeDlEZ0ZSbi8wellIS08rMFFRV2FYY2pROEU1Z3ln?= =?iso-2022-jp?B?ZGpiOXozRU5Pa3RBczF3cS9xcmxsUzRIVlBjUklwNFRUTGhWcTF3a29x?= =?iso-2022-jp?B?ZitsTjAza3B1NEFlTEwwVDdHVCsycG5SOVFnaGpTQnQ3WkdZTVBmMFY1?= =?iso-2022-jp?B?aGFHaGROeXcvbjV0cWJ3YjZVZVhqeTJVM0hnK3pidnByUWt3N3hHV0J3?= =?iso-2022-jp?B?bUlIaDY5S2lzRWtBcUhNUnlSVWtGYmExdWtDaHhsUG4rbndDOVUvN0Fw?= =?iso-2022-jp?B?ajYrTlNRamtXTlZYSDdQRmdzbTNrazdFVXE1ZXdwVzJRNy9rZXNBaGlR?= =?iso-2022-jp?B?WGgrNVZuTTlyMUR5YktybVZNSGJTQThoS3BpMGNzd2lkOWpFREdEVW1l?= =?iso-2022-jp?B?a3VTMnhmSzZFdSt1Zm5rRjJtd2R6V25DdFkwblo1WlR5RmxGTFdZdkVt?= =?iso-2022-jp?B?TzRoUDVMQnFVNzVGREdiOC8yeU03M25OM2Npd252RjRjMCtCdEJGalh5?= =?iso-2022-jp?B?OXpiTGp1VVVzZy91dDJHdWtOUkpqTFJGcHNuYUdJZUx1VGFqZVJCd0kz?= =?iso-2022-jp?B?bU45YWRIRDlleWhiZkgrMg==?= Content-ID: <45AEC839EF13FB4984DA5869108D5510@jpnprd01.prod.outlook.com> MIME-Version: 1.0 X-OriginatorOrg: nec.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: TY1PR01MB1852.jpnprd01.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: db092a07-eda8-46d3-993c-08d8b82eab15 X-MS-Exchange-CrossTenant-originalarrivaltime: 14 Jan 2021 01:49:45.0811 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: e67df547-9d0d-4f4d-9161-51c6ed1f7d11 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: EBbKCqF1lzsPhgStIKJQriHVRyWRdUwjrqGoU5iQbqDux/g6mo/G1rjFXz1ktl2tqTXhadoscgbDit/qmf0PvQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: TY2PR01MB4812 Message-ID-Hash: SAOQVHDXLS75CD2RW62PM6WYUFAE4Q44 X-Message-ID-Hash: SAOQVHDXLS75CD2RW62PM6WYUFAE4Q44 X-MailFrom: naoya.horiguchi@nec.com X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: "akpm@linux-foundation.org" , Naoya Horiguchi , Michal Hocko , David Hildenbrand , Oscar Salvador , "stable@vger.kernel.org" , "linux-mm@kvack.org" , "linux-nvdimm@lists.01.org" , "linux-kernel@vger.kernel.org" X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Wed, Jan 13, 2021 at 04:43:32PM -0800, Dan Williams wrote: > The conversion to move pfn_to_online_page() internal to > soft_offline_page() missed that the get_user_pages() reference taken by > the madvise() path needs to be dropped when pfn_to_online_page() fails. > Note the direct sysfs-path to soft_offline_page() does not perform a > get_user_pages() lookup. > > When soft_offline_page() is handed a pfn_valid() && > !pfn_to_online_page() pfn the kernel hangs at dax-device shutdown due to > a leaked reference. > > Fixes: feec24a6139d ("mm, soft-offline: convert parameter to pfn") > Cc: Andrew Morton > Cc: Naoya Horiguchi > Cc: Michal Hocko > Reviewed-by: David Hildenbrand > Reviewed-by: Oscar Salvador > Cc: > Signed-off-by: Dan Williams I'm OK if we don't have any other better approach, but the proposed changes make code a little messy, and I feel that get_user_pages() might be the right place to fix. Is get_user_pages() expected to return struct page with holding refcount for offline valid pages? I thought that such pages are only used by drivers for dax-devices, but that might be wrong. Can I ask for a little more explanation from this perspective? Thanks, Naoya Horiguchi > --- > mm/memory-failure.c | 20 ++++++++++++++++---- > 1 file changed, 16 insertions(+), 4 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 5a38e9eade94..78b173c7190c 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1885,6 +1885,12 @@ static int soft_offline_free_page(struct page *page) > return rc; > } > > +static void put_ref_page(struct page *page) > +{ > + if (page) > + put_page(page); > +} > + > /** > * soft_offline_page - Soft offline a page. > * @pfn: pfn to soft-offline > @@ -1910,20 +1916,26 @@ static int soft_offline_free_page(struct page *page) > int soft_offline_page(unsigned long pfn, int flags) > { > int ret; > - struct page *page; > bool try_again = true; > + struct page *page, *ref_page = NULL; > + > + WARN_ON_ONCE(!pfn_valid(pfn) && (flags & MF_COUNT_INCREASED)); > > if (!pfn_valid(pfn)) > return -ENXIO; > + if (flags & MF_COUNT_INCREASED) > + ref_page = pfn_to_page(pfn); > + > /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */ > page = pfn_to_online_page(pfn); > - if (!page) > + if (!page) { > + put_ref_page(ref_page); > return -EIO; > + } > > if (PageHWPoison(page)) { > pr_info("%s: %#lx page already poisoned\n", __func__, pfn); > - if (flags & MF_COUNT_INCREASED) > - put_page(page); > + put_ref_page(ref_page); > return 0; > } > > _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org