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 0459CC433EF for ; Tue, 12 Jul 2022 01:49:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3D12F94002F; Mon, 11 Jul 2022 21:49:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 380A5940010; Mon, 11 Jul 2022 21:49:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1FA7F94002F; Mon, 11 Jul 2022 21:49:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 0FE60940010 for ; Mon, 11 Jul 2022 21:49:42 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id D99C420E8D for ; Tue, 12 Jul 2022 01:49:41 +0000 (UTC) X-FDA: 79676766162.22.37E9C7A Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by imf06.hostedemail.com (Postfix) with ESMTP id 43ABD180027 for ; Tue, 12 Jul 2022 01:49:41 +0000 (UTC) Received: from pps.filterd (m0246632.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 26BMYnGR001823; Tue, 12 Jul 2022 01:49:15 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=70VnACj4dQ3VEkvuqpC4sR8E/kz4QTh2t2+ddhKFx8Q=; b=YqDvnvsFV0DBeG71QLPDP6LclFKJbJ+r1vPvvDDrNOD0yIrYa7cQoCtZUZEktsdLvTfq HC8cZVoa6EDKa5/cfR6e9H6WHSaJ6VcP23NgJ4QXpofe5rnU6Rg7eqfwLgS4GQLnBtN0 pBjFSjnFuY+TMefYLbtdorjDOSs3c7daY1pTnoH3volussof1wIzL+W5QofCtyiCWL/I MnanHCoLMD8pBadR0qCBH7Fhqbly3wN8o48fPmawsVv2DLALcVhhnK1BpuloMId6wt8h yV7Q01brzf+bulQE2B8tjI9jw2CNA86oCImaUsW7AExMlNHIDmN/ZoViVN2GKsnTRNG8 Ew== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3h71xrd4kq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Jul 2022 01:49:15 +0000 Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.16.1.2/8.16.1.2) with SMTP id 26C1fHOJ028175; Tue, 12 Jul 2022 01:49:14 GMT Received: from nam10-bn7-obe.outbound.protection.outlook.com (mail-bn7nam10lp2103.outbound.protection.outlook.com [104.47.70.103]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com with ESMTP id 3h70436w8e-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Jul 2022 01:49:14 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=h8zDB9M1rswwgg3pBAzT1avF+UtsBI2+Wz4P73EhdWFs87N2fOeOBpgWwcwWnuUc2AI5fldVcdCYqTH/zGB/Otd9HLKSP3/qeeVmrPjJmux2S4lF5fXQD8/GitNP4s4VY9RZthhB8L5prCD6+B5yyYVu8Njx5Z0c/LDQouoeYcDEQRUvBPGpq9vSCb2qSPN3xwG2VA/WTEdZYU72P44/xJgoYcKmseb5udGGgm1bL9H6XtSmFfzPlOJU5gyvnkbkwGchsefC+LdaEMnNcD/DSXnPqOKQr5442RnND58crA4WzgN6CG70vBWlXPGQ2ccNfd77DStuw/BhF3GSJ561tw== 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=70VnACj4dQ3VEkvuqpC4sR8E/kz4QTh2t2+ddhKFx8Q=; b=VPD92e+6hIY74s9ysuFyk3sR3jpQ/s0uR2QOUJgxdg7DK6qjmtl3zX0NG7FBw9hqWuUBdUPDckuAEkhAPSXQV7Q8S85H5HCtOkyi8JOz/7rdMCQJb9OZgfVRB5CLIcTRvS2PDZ37ji1Ne1S+FpOmM/i8yBH8OPuSFqbd4dAPEtvp49fdOPS/RX0x/hE7Bx0hGQ5vVqmicIYNz1rPALgA+vWYFjwEKqRCBFx5A8A61VyFGPbkngF+jNFT6jRwWVbRRW3iBYAeBdMC3xZa5dnrL12k3mX5hqDPC03NW6wIk5OJydxj/opw+CgBpHh9iOy0c2A0rCJIvjvmrx2Zhmrisg== 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=70VnACj4dQ3VEkvuqpC4sR8E/kz4QTh2t2+ddhKFx8Q=; b=dkBtaN9PN/eGhQSKMkwxg9o/AsTkzCqUmL1xoxTSUvQTkox4DBU3vsqPxc7DnDXGoPOJTTYKi8+COW58UGWgaa2E5oLlqlo/N9YUdzyuY4gvxPgXSxsV9dT4lwSy3OZMuNToIYFDvkJ5Smv/louLsxCkxoit4N3zbSA5QBv7EXw= Received: from SN6PR10MB3022.namprd10.prod.outlook.com (2603:10b6:805:d8::25) by IA1PR10MB6267.namprd10.prod.outlook.com (2603:10b6:208:3a1::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5417.26; Tue, 12 Jul 2022 01:49:13 +0000 Received: from SN6PR10MB3022.namprd10.prod.outlook.com ([fe80::c4d1:edc3:7d21:7c68]) by SN6PR10MB3022.namprd10.prod.outlook.com ([fe80::c4d1:edc3:7d21:7c68%6]) with mapi id 15.20.5417.026; Tue, 12 Jul 2022 01:49:13 +0000 From: Liam Howlett To: Alexander Gordeev CC: "maple-tree@lists.infradead.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Andrew Morton , "damon @ lists . linux . dev" , SeongJae Park , David Hildenbrand , Matthew Wilcox Subject: Re: [PATCH v10 13/69] mm/mmap: use maple tree for unmapped_area{_topdown} Thread-Topic: [PATCH v10 13/69] mm/mmap: use maple tree for unmapped_area{_topdown} Thread-Index: AQHYhbALqTBpFGf5+k+LdWHoM0UZLa11v9cAgARX6AA= Date: Tue, 12 Jul 2022 01:49:12 +0000 Message-ID: <20220712014902.3lfeaebfhyc4eakc@revolver> References: <20220621204632.3370049-1-Liam.Howlett@oracle.com> <20220621204632.3370049-14-Liam.Howlett@oracle.com> In-Reply-To: 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: 488853c3-2536-43ed-28c3-08da63a8b8ad x-ms-traffictypediagnostic: IA1PR10MB6267:EE_ 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:SN6PR10MB3022.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230016)(7916004)(396003)(39860400002)(346002)(136003)(366004)(376002)(38070700005)(86362001)(6506007)(76116006)(2906002)(122000001)(54906003)(66446008)(4326008)(38100700002)(91956017)(64756008)(33716001)(316002)(6916009)(66476007)(8676002)(66946007)(66556008)(9686003)(1076003)(41300700001)(44832011)(71200400001)(83380400001)(478600001)(6512007)(6486002)(186003)(26005)(8936002)(5660300002);DIR:OUT;SFP:1101; x-ms-exchange-antispam-messagedata-chunkcount: 1 x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?x50GYLpH1Bc8MkEQI5DBHQ7TJUaRaDhVtwObYigc0iSlnx6cmPx/F7wKXTU5?= =?us-ascii?Q?qwoSsTezWB2YWD4OqAmXVHmRDxO/k9XENqIvZrBO25Z6QU/SkHDl1AUATJtS?= =?us-ascii?Q?t5yAYfaHACRj3X6jrd4L/pk6HdzkhMyjF+YlgP5x0bxWbjg77hdLAw5wwmQf?= =?us-ascii?Q?bXcnotXSzkaDQGNPpCDkV5xUdo1xy47szzVhO89g2/k0O+iKJ660M3sCHgde?= =?us-ascii?Q?cenSX7kzubexlcN+xmmaSNdHNHWMqHD8Fj8pG1fOizoosbG5ulwp2kd/ZD12?= =?us-ascii?Q?X3/b0ygJBHQnQ/TFPPoLobiFA9vBBL6pqASNnM+Ct/NAaiTyHJuxlBT2SvlQ?= =?us-ascii?Q?sYm9q0VWGlJE+GTikgWucFup3XHLoESWfKhY/BZYuPoF2L+PI2vJhB6i68Hk?= =?us-ascii?Q?YOCE7QNm7fcHm1F20sO2/RKA2QkMUuK0yOeIKdCHNJwbrLRtenHqq5VX6wHC?= =?us-ascii?Q?7UV4ZZv3WWwaDbbJRj4qO9co8ZC5/VzQOI+W+FHcJ4pcW58eFQSMo3LEvgoN?= =?us-ascii?Q?J2tmlNCtXzUW3Ex5CnP5pzDGl2vOoLEyION21e5Qh1c4CDI4cg/wAp926/LQ?= =?us-ascii?Q?J8gk0xw1N8tN0B8LRqfUmpjhPUi2lOwLv5yWS5TZJho3fSeucXILhcubGPqH?= =?us-ascii?Q?JlOTnK6YOX0qSIZZ+2Y1pCH3HNykcIsyF3KMLV0v5WGUd6cGpUylZDnltV1N?= =?us-ascii?Q?K7KdCyVzt6G9DzX+SeUEYbcoB8vdVDYl6AfKDFZi4h8VDknV28tcYXqutfT5?= =?us-ascii?Q?M+pXF1iF7a6btbfwsS6IqvHciCRrqMaijl+e5FvM7LA8v2RrJNnV9ei/fpy9?= =?us-ascii?Q?vysQIAPO356CfOxWnvcNk/cXnOU6RSlZpC//cwxWue65g/egB+c8GkkWCpA7?= =?us-ascii?Q?bWtM8O5M+pDQC2vnTBCOvUB1vI4wRTVzKX19gcHCyOrt8sV9bYHSMPI3A6az?= =?us-ascii?Q?qH0nDQkYnDB/Tg8k+9PbZuDqk8CxqIkvNwulfoEYH4SYsVef+AQTLUI1Xp+l?= =?us-ascii?Q?cRv+h7kPU4z4K2u+N/qKaNQnUkDsbvQUD6CguYztFb+kxZY43BeBjjk3AL9O?= =?us-ascii?Q?yo0TUAYopPPUryTZS+8H7XQwL0xX81vtnNMPhOUGWQDpUJmAtVl7pyx2iAoj?= =?us-ascii?Q?PFhBRjaYqIIArt2RDRWZXOayvQDRVKkvb0DRHFzVZK+jqX5pK1NyIjPP0NbT?= =?us-ascii?Q?T1nfveqLPytmGbcEjGJnR1hbK2uRSauTVVO0RyhBZpSOxAaFI/nwXXEv+c3y?= =?us-ascii?Q?Q8kPEA9l51TcMJiz7iO+c2rvLXruOaK6P9CVDsE6wXZ0iaRRN2ZxLN2RUq7N?= =?us-ascii?Q?km5tca1Ku87cv1LmgF/FaecMEk/JMGAWNUlXSvLDyOvPPU6gx+EhZfnOq0KT?= =?us-ascii?Q?QCerQ9GBrjaeNt4v1dusUg4duwrL0kdNAonbTul3DDECKEKbhYtcWf93kmVL?= =?us-ascii?Q?xoAQB01alkxvRNlPR08ZIpi4Va06NF5sCvZ5niTpH+U20+0178LWwMcMLlcL?= =?us-ascii?Q?lyk9vZYSjdeoGbr6888j/Rblm3dw5T7BY1uB/Dev57aX3mNa9TzVfls+TA9n?= =?us-ascii?Q?4BQX3LP1nB0X/Ed7K0jxii6YnPqDY40+7RBlNUzH6GA9y8gB+ymFzA83a9cZ?= =?us-ascii?Q?Vg=3D=3D?= Content-Type: text/plain; charset="us-ascii" Content-ID: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: SN6PR10MB3022.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 488853c3-2536-43ed-28c3-08da63a8b8ad X-MS-Exchange-CrossTenant-originalarrivaltime: 12 Jul 2022 01:49:12.9889 (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: neXgzhUFOE2zvt4YME65zXL2sk4yWxc6EaCv//47k+0bWZhZqwNaZz/8STEC52Q3LnPalYd0fmOUYe1LApXgZw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR10MB6267 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.517,18.0.883 definitions=2022-07-12_01:2022-07-08,2022-07-11 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 phishscore=0 mlxscore=0 suspectscore=0 adultscore=0 spamscore=0 mlxlogscore=999 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2206140000 definitions=main-2207120005 X-Proofpoint-GUID: DXglZrQf5khpe9kADMOZmorbGW1ueoe_ X-Proofpoint-ORIG-GUID: DXglZrQf5khpe9kADMOZmorbGW1ueoe_ ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1657590581; 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=70VnACj4dQ3VEkvuqpC4sR8E/kz4QTh2t2+ddhKFx8Q=; b=27wRcf+TevHmKJl3CFcUli2f5jilEx2Si+RVd5Fgaz1qARFaX/qs9wIMMatwpUV5XcrxGt gCf8w6bSxvBZh8cleFAtvHxh96Xvj5OeAieQxMJ7sJn17dPCuZ2tFS5rJ7mEHrN9pYdviG hOsaArWpZABi98HeQ7qHPbZj3DrfPZI= ARC-Authentication-Results: i=2; imf06.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2021-07-09 header.b=YqDvnvsF; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=dkBtaN9P; spf=none (imf06.hostedemail.com: domain of liam.howlett@oracle.com has no SPF policy when checking 205.220.177.32) smtp.mailfrom=liam.howlett@oracle.com; arc=pass ("microsoft.com:s=arcselector9901:i=1"); dmarc=pass (policy=none) header.from=oracle.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1657590581; a=rsa-sha256; cv=pass; b=cl1cLYRC3mC8TEEMpDptxSi4tC5ES3rwrkAowGASFOiKlfoOk6l8R2dUv7+OfFzRMIrZgc o0hn7D4qD3V9X8e7gQ1L3UInlfquVD/67464W5asLOc55rTGIAu8KXcDrunuP/wFHUJvH8 O/pC+B+buT22Vq3gxV64R7cxbRVTV24= X-Rspamd-Server: rspam02 X-Stat-Signature: zrauhqxi4k7opnu6oindyky44y1cprte X-Rspamd-Queue-Id: 43ABD180027 X-Rspam-User: Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2021-07-09 header.b=YqDvnvsF; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=dkBtaN9P; spf=none (imf06.hostedemail.com: domain of liam.howlett@oracle.com has no SPF policy when checking 205.220.177.32) smtp.mailfrom=liam.howlett@oracle.com; arc=pass ("microsoft.com:s=arcselector9901:i=1"); dmarc=pass (policy=none) header.from=oracle.com X-HE-Tag: 1657590581-21932 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: * Alexander Gordeev [220709 03:29]: > On Tue, Jun 21, 2022 at 08:46:55PM +0000, Liam Howlett wrote: > > From: "Liam R. Howlett" > >=20 > > The maple tree code was added to find the unmapped area in a previous > > commit and was checked against what the rbtree returned, but the actual > > result was never used. Start using the maple tree implementation and > > remove the rbtree code. > >=20 > > Add kernel documentation comment for these functions. >=20 > Hi Liam, >=20 > With this update a user process crash is triggered on s390 when > the below core is executed (derived from LTP fork14 testcase): >=20 > #include > #include >=20 > #define GB (1024 * 1024 * 1024L) > #define EXTENT (16 * 1024 + 10) >=20 > int main(int argc, char **argv) > { > void *addr; > int i; >=20 > for (i =3D 0; i < EXTENT; i++) { > addr =3D mmap(NULL, 1 * GB, PROT_READ | PROT_WRITE, > MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); > if (addr =3D=3D MAP_FAILED) > break; > } >=20 > return 0; > } >=20 > On 4095-th iteration mmap() returns a normal address, but shared > library mappings go away. The page tables seem to be intact as the > memory is still available (I did not check every mapping gone though). > In addition, the memory contents of disappeared mappings is zeroed. > As result, an instruction that follows the mmap() system call turns > into invalid operation code: >=20 > t35lp64 login: [45116.631391] User process fault: interruption code 0004 = ilc:1=20 > [45116.631403] Failing address: 000003ffa580c000 TEID: 000003ffa580c884 > [45116.631405] Fault in primary space mode while using user ASCE. > [45116.631407] AS:00000000e75fc1c7 R3:00000000e758c007 S:00000000a3e01701= =20 > [45116.631411] CPU: 4 PID: 1745 Comm: mmap Not tainted 5.19.0-rc4-00162-g= 34de4ebd5706 #36 > [45116.631414] Hardware name: IBM 8561 T01 703 (LPAR) > [45116.631416] User PSW : 0705000180000000 000003ffa580cc38 > [45116.631418] R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:1 AS:0 CC:0 P= M:0 RI:0 EA:3 > [45116.631420] User GPRS: 0000000000000000 000003ffa5af4040 000003ff65afb= 000 0000000040000000 > [45116.631422] 0000000000000003 0000000000000022 0000000000000= 000 0000000001003e00 > [45116.631423] 000003ffa5ab0b48 000003ffa5ab1018 0000000000000= 001 000003fff5879500 > [45116.631425] 000003ffa5ab0f70 0000000000000000 0000000001001= 218 000003fff5879428 > [45116.631429] User Code: 000003ffa580cc32: 0000 illegal=20 > [45116.631429] 000003ffa580cc34: 0000 illegal=20 > [45116.631429] #000003ffa580cc36: 0000 illegal=20 > [45116.631429] >000003ffa580cc38: 0000 illegal=20 > [45116.631429] 000003ffa580cc3a: 0000 illegal=20 > [45116.631429] 000003ffa580cc3c: 0000 illegal=20 > [45116.631429] 000003ffa580cc3e: 0000 illegal=20 > [45116.631429] 000003ffa580cc40: 0000 illegal=20 > [45116.631437] Last Breaking-Event-Address: > [45116.631438] [<0000000000000001>] 0x1 >=20 > In other words, if before the mmap() call memory mappings look like this: >=20 > Start Addr End Addr Size Offset Perms obj= file > 0x1000000 0x1001000 0x1000 0x0 r--p /ro= ot/main/mmap > 0x1001000 0x1002000 0x1000 0x1000 r-xp /ro= ot/main/mmap > 0x1002000 0x1003000 0x1000 0x2000 r--p /ro= ot/main/mmap > 0x1003000 0x1004000 0x1000 0x2000 r--p /ro= ot/main/mmap > 0x1004000 0x1005000 0x1000 0x3000 rw-p /ro= ot/main/mmap > 0x3fff7c00000 0x3fff7c2b000 0x2b000 0x0 r--p /us= r/lib64/libc.so.6 > 0x3fff7c2b000 0x3fff7d64000 0x139000 0x2b000 r-xp /us= r/lib64/libc.so.6 > 0x3fff7d64000 0x3fff7dc3000 0x5f000 0x164000 r--p /us= r/lib64/libc.so.6 > 0x3fff7dc3000 0x3fff7dc4000 0x1000 0x1c3000 ---p /us= r/lib64/libc.so.6 > 0x3fff7dc4000 0x3fff7dc8000 0x4000 0x1c3000 r--p /us= r/lib64/libc.so.6 > 0x3fff7dc8000 0x3fff7dca000 0x2000 0x1c7000 rw-p /us= r/lib64/libc.so.6 > 0x3fff7dca000 0x3fff7dd2000 0x8000 0x0 rw-p =20 > 0x3fff7f80000 0x3fff7f82000 0x2000 0x0 r--p /us= r/lib/ld64.so.1 > 0x3fff7f82000 0x3fff7fa3000 0x21000 0x2000 r-xp /us= r/lib/ld64.so.1 > 0x3fff7fa3000 0x3fff7faf000 0xc000 0x23000 r--p /us= r/lib/ld64.so.1 > 0x3fff7faf000 0x3fff7fb1000 0x2000 0x2e000 r--p /us= r/lib/ld64.so.1 > 0x3fff7fb1000 0x3fff7fb3000 0x2000 0x30000 rw-p /us= r/lib/ld64.so.1 > 0x3fff7ff3000 0x3fff7ffb000 0x8000 0x0 rw-p =20 > 0x3fffffda000 0x3ffffffb000 0x21000 0x0 rw-p [st= ack] > 0x3ffffffc000 0x3ffffffe000 0x2000 0x0 r--p [vv= ar] > 0x3ffffffe000 0x40000000000 0x2000 0x0 r-xp [vd= so] >=20 > Then after mmap() returns it turns into: >=20 > Start Addr End Addr Size Offset Perms obj= file > 0x1000000 0x1001000 0x1000 0x0 r--p /ro= ot/main/mmap > 0x1001000 0x1002000 0x1000 0x1000 r-xp /ro= ot/main/mmap > 0x1002000 0x1003000 0x1000 0x2000 r--p /ro= ot/main/mmap > 0x1003000 0x1004000 0x1000 0x2000 r--p /ro= ot/main/mmap > 0x1004000 0x1005000 0x1000 0x3000 rw-p /ro= ot/main/mmap > 0x37c00000 0x3fff7ffb000 0x3ffc03fb000 0x0 rw-p = =20 > 0x3fffffda000 0x3ffffffb000 0x21000 0x0 rw-p [st= ack] > 0x3ffffffc000 0x3ffffffe000 0x2000 0x0 r--p [vv= ar] > 0x3ffffffe000 0x40000000000 0x2000 0x0 r-xp [vd= so] >=20 > Interestingly, all addresses mmap() returns before the problem hits are > 1MB-aligned, while the last one that screws the mappings is always page- > aligned. Also, the iteration number 4095 suggests some arithmetics that > leads to an integer overflow. >=20 > I did not experiment much with x86, but the problem does not hit there. > The config has CONFIG_PGTABLE_LEVELS=3D5, but I am not sure about other > options that may be involved. >=20 > The tree I used to isolate the issue: >=20 > git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm mm-everything >=20 > It (looks like it) gets pulled into every linux-next, so the problem > is reproducable there as well. >=20 > As we are approaching the merge window that looks pretty worrisome. I wil= l=20 > try to get more details on what is going on, but may be you have an immed= iate > idea? Thank you for testing this code. Yes, it is because I was not returning the error code which I had set when gap searching was exhausted. What is happening is that, because I had not returned the error, the mmap code will munmap the area and replace it with your requested map. There will be a patch for the maple tree in your inbox shortly. Regards, Liam