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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 4D326C433EF for ; Wed, 8 Sep 2021 03:10:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D1D2960F6C for ; Wed, 8 Sep 2021 03:10:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D1D2960F6C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 6C42A940067; Tue, 7 Sep 2021 23:10:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 64C8B940042; Tue, 7 Sep 2021 23:10:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 45294940067; Tue, 7 Sep 2021 23:10:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0079.hostedemail.com [216.40.44.79]) by kanga.kvack.org (Postfix) with ESMTP id 2DED5940042 for ; Tue, 7 Sep 2021 23:10:28 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id E35A3182301F4 for ; Wed, 8 Sep 2021 03:10:27 +0000 (UTC) X-FDA: 78562928094.20.2A29244 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf17.hostedemail.com (Postfix) with ESMTP id 58D45F00038C for ; Wed, 8 Sep 2021 03:10:27 +0000 (UTC) Received: from pps.filterd (m0246617.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 187LU0uQ025812; Wed, 8 Sep 2021 03:10:05 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-id : content-transfer-encoding : mime-version; s=corp-2021-07-09; bh=indz5TpFY+NcrAXdaM+ndfSZB2PN60HrVqTcQVds9SA=; b=TulnVCQCIPDKV4HQLu+oqe4u0L32WMSLLHzgDPu6Il5TA65o/19F2uIMbBFjydX3ouoS GQpAx2c3wvz+zts7pTZQSB0mvrtS2Rw9v39D5l/6GhB5+9/3yqNseb+K8Tpe29Mcd1HP 8j2TaxW7ELqtSnwis3BS8GYWFUOPmPnvu1/jkBYEM4+hV0CpYE3k8CGuFnb6rT1/2t8H KS/YQc+Nf5OHW8C0XDm6Rt0vS4ZuImjXN94xhTJSKOfYaJigGAu3yeviC5uQoEqk/00R 2U9NKSNqpb1uBMJI2ndRLANo/fjMpkU3ehwUvw29zNJANthbmNgw40uZMwNS88wA6Osw Hg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-id : content-transfer-encoding : mime-version; s=corp-2020-01-29; bh=indz5TpFY+NcrAXdaM+ndfSZB2PN60HrVqTcQVds9SA=; b=NiHKr3OxbCdtt/0b+LH0kg2z8Ge8xQ5ozpmGXhy1qw6U16O6csBS+57O0wUnVV3C44XU u8c2pklAsolKj5WrBy7HCiRiCYxALeWFpPGOdz0dYxSUhdX+vVk3AxrIk1kqMF3d1MFI QVq5pk1DrjFNbLXQuLgdttG7PLJvBhJPTpxKsVZgrJLIWtqN1PM6NcKAWLk62ryd6imn o6JnXgPUHIFJ9CuYIb05ImX66zm3C4KFW8vWqtfftcoAnwBWiQM+vfKJJvrpfu8iCSj7 yfTmrgr/34EZHlHqCdQf3ESJquZ4qS1jHRmcXNASP8mCtCpWr5BGa6+fr1yrNO1aAT/7 JQ== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by mx0b-00069f02.pphosted.com with ESMTP id 3axd8q12rn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 08 Sep 2021 03:10:04 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 1883A2Bj093797; Wed, 8 Sep 2021 03:10:03 GMT Received: from nam11-dm6-obe.outbound.protection.outlook.com (mail-dm6nam11lp2172.outbound.protection.outlook.com [104.47.57.172]) by aserp3020.oracle.com with ESMTP id 3axcpkkffw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 08 Sep 2021 03:10:03 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=ANq9rp8w20avarVds+HmXtgnt8klONHLLDfM8PpjxORTcI30VbFoC+iEvYhzDC/7vf+7QzXgj+PDws+nElZhOZtqv+pJMJBSktCPv5h9jSNB81W3KZBECzPKCivvkdKiU/n8PK3Qu9Yqg6tmaHSLfnS5QalAx7bSiaHnG+SXAvEq8tcV7tN9xcTvBxKvBK2pDsGsS6u+zax5XOAkyenUoTyaBjt11LjXqXw5qAx7k3U6xCNGjIBZH58ciqH+aGLhuvGe1PsGkJbef0NCsUwSYExxfqIvftH0jjOHqJ8A1k6A6/hHhePnqWI1JUokGQ9QqL/Li4LU2kWFZJaUYEUKiQ== 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; bh=indz5TpFY+NcrAXdaM+ndfSZB2PN60HrVqTcQVds9SA=; b=m2UWQmGLyyZvjt0W45gt159v5QjSTKGxSTtOMR29z/Omb+wPAcbiA2iuxHgaaTepsM3jXumtGF4P8VzE22MfQPXyphFfXgjGZMH1o4eZf/mr8XwNjZQqbNW8PAzxYcqnbBVQdvO+JkYApczrAsv25RmuvxwqMwaVtsOoT0Rg+SDmOeHLYHTonRBleMi2LhDMY5tj5NcfAWrCypt6fXN8T83rsb6NYZSX7FaBsvIXapvQ3QW+f4fAfK9fuWNJksbHptwW0r+5BEkNxjY86gMDt98ta1MrrfRTvSxYhJj3WR6DV9sc9h1pncLiOD8BjfTosecEsLLWW/iX0P7FYBSFOA== 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=indz5TpFY+NcrAXdaM+ndfSZB2PN60HrVqTcQVds9SA=; b=0I0UQ5pd1I2WsL+K1VUX0Sy7G3BrSLdUx8nUH+KtutECoopfgo3wbkXoD5gFBBNBpIi6pg9B70Tf8FX8XBrTZkb29/Abb4iOWxytxx1LDxHd7OJt1mLdA+bZxvkc5QpA+Y71i3xZ7Ccr/zvFYGzwUHLEFzuYRIzfYHK8vuaO47A= Received: from DM6PR10MB4380.namprd10.prod.outlook.com (2603:10b6:5:223::19) by DM5PR10MB1356.namprd10.prod.outlook.com (2603:10b6:3:11::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4478.22; Wed, 8 Sep 2021 03:09:49 +0000 Received: from DM6PR10MB4380.namprd10.prod.outlook.com ([fe80::f4b1:d890:7745:30a3]) by DM6PR10MB4380.namprd10.prod.outlook.com ([fe80::f4b1:d890:7745:30a3%4]) with mapi id 15.20.4478.026; Wed, 8 Sep 2021 03:09:49 +0000 From: Liam Howlett To: Yonghong Song CC: "bpf@vger.kernel.org" , "linux-mm@kvack.org" , Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , "kernel-team@fb.com" , Luigi Rizzo Subject: Re: [PATCH mm] mm/mmap: relax mmap_assert_locked() for find_vma() Thread-Topic: [PATCH mm] mm/mmap: relax mmap_assert_locked() for find_vma() Thread-Index: AQHXo7Fh8ctBc8s7u0yUW+pa6CAvZKuZdouA Date: Wed, 8 Sep 2021 03:09:49 +0000 Message-ID: <20210908030941.rfew4t63fw4s4bpz@revolver> References: <20210907062650.1309736-1-yhs@fb.com> In-Reply-To: <20210907062650.1309736-1-yhs@fb.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 235db0e6-60e9-4b01-879f-08d972761ec8 x-ms-traffictypediagnostic: DM5PR10MB1356: x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:10000; x-ms-exchange-senderadcheck: 1 x-ms-exchange-antispam-relay: 0 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:DM6PR10MB4380.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(7916004)(366004)(39860400002)(396003)(376002)(346002)(136003)(38100700002)(6486002)(86362001)(33716001)(8676002)(2906002)(44832011)(6506007)(83380400001)(316002)(186003)(4326008)(8936002)(478600001)(76116006)(66476007)(91956017)(64756008)(66556008)(66446008)(66946007)(6512007)(9686003)(5660300002)(26005)(38070700005)(54906003)(122000001)(45080400002)(71200400001)(6916009)(1076003);DIR:OUT;SFP:1101; x-ms-exchange-antispam-messagedata-chunkcount: 1 x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?CrvRNUf8e6eBNTDsWdXGLjZh3YmqPkOgfT1hdd4JS6MJLxfC17RjISylL9KU?= =?us-ascii?Q?KeKN4/l34mi9xX682+46WD4pRwE8MXjW2FGitWYPCT8yVFiol3OrHtmR4Ibh?= =?us-ascii?Q?PPg5Lkqq+emuP4pn+uY++02FNM00b7DRYYCteJ7rAA7d8PpLsB/59LewR2si?= =?us-ascii?Q?z4/nzDpsjrmalDpvujSlFb4ULt1nmbAbUw5A2Z64QrRlCbqPfXpddsIkBsgQ?= =?us-ascii?Q?5CGZw3TvgKc0+mKYKAQCIQ07vKiDMv3V4C979Tib2RaN7blNJKHlT0LWmenu?= =?us-ascii?Q?VJXBGv4eWIKwdgeJo/r5DyQMxCOnKPcUBO3RbV4H/hv5w7BCqNanoi9oxq8k?= =?us-ascii?Q?6kFfEqspsaXYFNwPYUlXP1IS3W5P9hVfNCeKAC8tj2ysCEVFldjwZ4CynC4R?= =?us-ascii?Q?2UOkQp3aBjfo7eVCJkxgUZBOiaGZkSffLxy34guKnm/1tCTdBoxzvD0hzzU9?= =?us-ascii?Q?hIPda8XCEnH3lRV+Y72uTnY80mamq70Ep4XEfmQ9UAG8fZmlGLB7D8aYNknd?= =?us-ascii?Q?5iTHt+U3PumuNRJb2ahV31b+mJQrLKoECQc1fT/E0XfRhzAT351c3Sd3DEz6?= =?us-ascii?Q?Yk2XfsYIXdkdgXnfw9494RFtopFOF+rDuuvUZp0sASiiChPjY+qGMWLpdfEq?= =?us-ascii?Q?x3gqeYnYfRpczXj56LGB4YUuQTUscjbC368dQlrYfe6xh9HQH4AAmMkv3gNl?= =?us-ascii?Q?e8HtKVJ5JyjHrmPucQSlpgRQyGrQebALcCe8tK/Kdyp/TRJnK6RmqnxMuB8K?= =?us-ascii?Q?oCLMoNvoq8c2DK1jd9KSBLGhxEISzG7d1qb+sjNPPylrc6e+Gb+IHM7YbuKF?= =?us-ascii?Q?4NJ46uIz2rppl2rHZ+dr3M9+0KcXcDNb/py7iYQe5Fdg4lHO8ftGdygFILC3?= =?us-ascii?Q?n5mmYbyp5sS5bZrLSoQmbpku//ebUimRRDgBsLhwDk81ty55Rk4qOu7vzcbD?= =?us-ascii?Q?bnNyXkkP4nbxI1t2ITf6UwfraxDuNDWHoHEDXJPsTMG7pwlU6wgi4POq2T/H?= =?us-ascii?Q?d3Y+xdPBh7s5qMoo1uJgo86ZL0HAk3pzs6UWGrP67Sn2iQVPG0pH15OxOztV?= =?us-ascii?Q?7dUAXNGIY8FSa83bQrk+cW6FG3QwQ6YmfRFEa10jH64iM3qnzG8lMngUSwUg?= =?us-ascii?Q?u9MkPAS5CREl15iiqUAlqv5JSm0uHo3DZJDL/e9xjbY+m2R5Eb+0wk/iBmDF?= =?us-ascii?Q?d46kgDFndsIlQMHYK0FdmtHQyFEIE1cWJ3MSaCUaRda3vBim5vjnDpos127f?= =?us-ascii?Q?V78RwmQhT5mMFgAIB3NxwO5bObZGOrKgIcT+lmEPxr+R6fJ5O2n5NTW7Lo3h?= =?us-ascii?Q?MYOBsbX8akNd2oTycUXAYEG9?= x-ms-exchange-transport-forked: True Content-Type: text/plain; charset="us-ascii" Content-ID: <4794ABB6ACEF734195A99F9CA04813B5@namprd10.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: DM6PR10MB4380.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 235db0e6-60e9-4b01-879f-08d972761ec8 X-MS-Exchange-CrossTenant-originalarrivaltime: 08 Sep 2021 03:09:49.6825 (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: k4YHE3G8UudsRKN2n0TK2gYE60ggVJgewG/FSbpeJUTFvS7L/tml9ob2HdzcbbySkRkQlk21E7zjzHzcqSI8Eg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM5PR10MB1356 X-Proofpoint-Virus-Version: vendor=nai engine=6300 definitions=10100 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 suspectscore=0 malwarescore=0 spamscore=0 mlxscore=0 phishscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2109030001 definitions=main-2109080019 X-Proofpoint-GUID: bySOgt172_fqpS-wht_WSV9gGBDWlXsU X-Proofpoint-ORIG-GUID: bySOgt172_fqpS-wht_WSV9gGBDWlXsU X-Rspamd-Queue-Id: 58D45F00038C Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2021-07-09 header.b=TulnVCQC; dkim=pass header.d=oracle.com header.s=corp-2020-01-29 header.b=NiHKr3Ox; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=0I0UQ5pd; dmarc=pass (policy=none) header.from=oracle.com; spf=none (imf17.hostedemail.com: domain of liam.howlett@oracle.com has no SPF policy when checking 205.220.165.32) smtp.mailfrom=liam.howlett@oracle.com X-Rspamd-Server: rspam01 X-Stat-Signature: wphrppk6o94us1k3a18xgb6bqq1n75xf X-HE-Tag: 1631070627-859964 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: * Yonghong Song [210907 02:27]: > Current bpf-next bpf selftest "get_stack_raw_tp" triggered the warning: >=20 > [ 1411.304463] WARNING: CPU: 3 PID: 140 at include/linux/mmap_lock.h:16= 4 find_vma+0x47/0xa0 > [ 1411.304469] Modules linked in: bpf_testmod(O) [last unloaded: bpf_te= stmod] > [ 1411.304476] CPU: 3 PID: 140 Comm: systemd-journal Tainted: G = W O 5.14.0+ #53 > [ 1411.304479] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), B= IOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 > [ 1411.304481] RIP: 0010:find_vma+0x47/0xa0 > [ 1411.304484] Code: de 48 89 ef e8 ba f5 fe ff 48 85 c0 74 2e 48 83 c4= 08 5b 5d c3 48 8d bf 28 01 00 00 be ff ff ff ff e8 2d 9f d8 00 85 c0 75 d4= <0f> 0b 48 89 de 48 8 > [ 1411.304487] RSP: 0018:ffffabd440403db8 EFLAGS: 00010246 > [ 1411.304490] RAX: 0000000000000000 RBX: 00007f00ad80a0e0 RCX: 0000000= 000000000 > [ 1411.304492] RDX: 0000000000000001 RSI: ffffffff9776b144 RDI: fffffff= f977e1b0e > [ 1411.304494] RBP: ffff9cf5c2f50000 R08: ffff9cf5c3eb25d8 R09: 0000000= 0fffffffe > [ 1411.304496] R10: 0000000000000001 R11: 00000000ef974e19 R12: ffff9cf= 5c39ae0e0 > [ 1411.304498] R13: 0000000000000000 R14: 0000000000000000 R15: ffff9cf= 5c39ae0e0 > [ 1411.304501] FS: 00007f00ae754780(0000) GS:ffff9cf5fba00000(0000) kn= lGS:0000000000000000 > [ 1411.304504] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 1411.304506] CR2: 000000003e34343c CR3: 0000000103a98005 CR4: 0000000= 000370ee0 > [ 1411.304508] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000= 000000000 > [ 1411.304510] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000= 000000400 > [ 1411.304512] Call Trace: > [ 1411.304517] stack_map_get_build_id_offset+0x17c/0x260 > [ 1411.304528] __bpf_get_stack+0x18f/0x230 > [ 1411.304541] bpf_get_stack_raw_tp+0x5a/0x70 > [ 1411.305752] RAX: 0000000000000000 RBX: 5541f689495641d7 RCX: 0000000= 000000000 > [ 1411.305756] RDX: 0000000000000001 RSI: ffffffff9776b144 RDI: fffffff= f977e1b0e > [ 1411.305758] RBP: ffff9cf5c02b2f40 R08: ffff9cf5ca7606c0 R09: ffffcbd= 43ee02c04 > [ 1411.306978] bpf_prog_32007c34f7726d29_bpf_prog1+0xaf/0xd9c > [ 1411.307861] R10: 0000000000000001 R11: 0000000000000044 R12: ffff9cf= 5c2ef60e0 > [ 1411.307865] R13: 0000000000000005 R14: 0000000000000000 R15: ffff9cf= 5c2ef6108 > [ 1411.309074] bpf_trace_run2+0x8f/0x1a0 > [ 1411.309891] FS: 00007ff485141700(0000) GS:ffff9cf5fae00000(0000) kn= lGS:0000000000000000 > [ 1411.309896] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 1411.311221] syscall_trace_enter.isra.20+0x161/0x1f0 > [ 1411.311600] CR2: 00007ff48514d90e CR3: 0000000107114001 CR4: 0000000= 000370ef0 > [ 1411.312291] do_syscall_64+0x15/0x80 > [ 1411.312941] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000= 000000000 > [ 1411.313803] entry_SYSCALL_64_after_hwframe+0x44/0xae > [ 1411.314223] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000= 000000400 > [ 1411.315082] RIP: 0033:0x7f00ad80a0e0 > [ 1411.315626] Call Trace: > [ 1411.315632] stack_map_get_build_id_offset+0x17c/0x260 >=20 > To reproduce, first build `test_progs` binary: > make -C tools/testing/selftests/bpf -j60 > and then run the binary at tools/testing/selftests/bpf directory: > ./test_progs -t get_stack_raw_tp >=20 > The warning is due to commit 5b78ed24e8ec("mm/pagemap: add mmap_assert_lo= cked() annotations to find_vma*()") > which added mmap_assert_locked() in find_vma() function. The mmap_assert_= locked() function > asserts that mm->mmap_lock needs to be held. But this is not the case for > bpf_get_stack() or bpf_get_stackid() helper (kernel/bpf/stackmap.c), whic= h > uses mmap_read_trylock_non_owner() instead. Since mm->mmap_lock is not he= ld > in bpf_get_stack[id]() use case, the above warning is emitted during test= run. >=20 > This patch fixed the issue by replacing mmap_assert_locked() with rwsem_i= s_locked(&mm->mmap_lock) > in find_vma(). I'm not a fan of removing the lockdep check. I'd rather see find_vma() do the lockdep and call another internal function which does exactly what you have below. Then you could call the one and everyone else could keep the code they have. More importantly, since this is the only user of the mmap_read_trylock_non_owner(), is there a build bot that could be used to catch errors introduced in this path? Thanks, Liam >=20 > Cc: Luigi Rizzo > Fixes: 5b78ed24e8ec("mm/pagemap: add mmap_assert_locked() annotations to = find_vma*()") > Signed-off-by: Yonghong Song > --- > mm/mmap.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) >=20 > Alternatively we could add a bool argument to find_vma to indicate whethe= r > mm->mmap_lock has been held or not. But I would like to report and try th= e > simpler solution first. >=20 > diff --git a/mm/mmap.c b/mm/mmap.c > index 88dcc5c25225..8c78b85475b1 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -2275,7 +2275,7 @@ struct vm_area_struct *find_vma(struct mm_struct *m= m, unsigned long addr) > struct rb_node *rb_node; > struct vm_area_struct *vma; > =20 > - mmap_assert_locked(mm); > + VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm); > /* Check the cache first. */ > vma =3D vmacache_find(mm, addr); > if (likely(vma)) > --=20 > 2.30.2 >=20 > =