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 C143BC27C4F for ; Thu, 27 Jun 2024 01:15:39 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4330A6B00C9; Wed, 26 Jun 2024 21:15:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3E1EC6B00CA; Wed, 26 Jun 2024 21:15:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 198D36B00CB; Wed, 26 Jun 2024 21:15:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id EB5406B00C9 for ; Wed, 26 Jun 2024 21:15:38 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 856CC141773 for ; Thu, 27 Jun 2024 01:15:38 +0000 (UTC) X-FDA: 82274901156.06.2DB92D9 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf27.hostedemail.com (Postfix) with ESMTP id 1238340016 for ; Thu, 27 Jun 2024 01:15:34 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=WcoXhMRm; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=JtmzMYJY; arc=pass ("microsoft.com:s=arcselector9901:i=1"); spf=pass (imf27.hostedemail.com: domain of liam.howlett@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=liam.howlett@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1719450918; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=PmOqPQYXrPCu3EN02qEICToIuw23wCIT7mG8Mpz6TrY=; b=uSZ85eXwkJr0X4k6WeQgYowkfURzunpj5QgC1wSStKHIk60BSQ0nhjIWg6CJfO8E4+ywkV G/MEfeLZ09iv40jryjvl/lDOa4wXrO0FlsjDR9VqQDWjdbfema9tngAoJZms37bEANf4F4 o85QAY7JgOfJVg0ldEs/gfhI1o4ldOs= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1719450918; a=rsa-sha256; cv=pass; b=oDQAunYTHnUJ+6FnRPxkpLLCD5ulH2cQkMQST0LjZl6ZNreeD04Bo0/7RMxb2e1raIJh5Q YFg2zWtUFTd2BQv0LubSDCT7jVUP1/D8kRq94+R7qP1tCEvnqhW5q38dZ154U2YAHLCner baqXDTnyX+VXt2pPpOHzS9UCugHgFEs= ARC-Authentication-Results: i=2; imf27.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=WcoXhMRm; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=JtmzMYJY; arc=pass ("microsoft.com:s=arcselector9901:i=1"); spf=pass (imf27.hostedemail.com: domain of liam.howlett@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=liam.howlett@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com Received: from pps.filterd (m0246617.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 45QLMbjQ011107; Thu, 27 Jun 2024 01:15:24 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h= date:from:to:cc:subject:message-id:references:content-type :in-reply-to:mime-version; s=corp-2023-11-20; bh=PmOqPQYXrPCu3EN 02qEICToIuw23wCIT7mG8Mpz6TrY=; b=WcoXhMRmGpQLoO3MvjB2usXcNZ547w4 oTA96i/lOuepoVNiKVgxiaTG+P5VwKDw4C65WZtHaC0rYbKFfL9JPZ9h2iaxWFfj kYFlQoF6+KCM8XVPocsUkXn8LpLEtRsYJIamAvc9hzFJ1XSL8MypKfCUmY0mNCa6 5niXxdXnWYxt9nvEZlhojL16zzaIFhSshGiCXM5cRdB0M8w5MZO68MfX18zdcS4O m6AbYXxu0zuoiwX8mM/vQfLa7MMQ+pQKVGXM3PeN+FkjyRdNugLNd2IgsW8/byQa DsK+oGk+wSjOdrkzZEpHpxXCmjQdPnxfSvl4bdmTeXqCdbxfyg5JSkw== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3ywq5t4qwq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 27 Jun 2024 01:15:24 +0000 (GMT) Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 45QMo0YC001295; Thu, 27 Jun 2024 01:15:23 GMT Received: from nam12-mw2-obe.outbound.protection.outlook.com (mail-mw2nam12lp2040.outbound.protection.outlook.com [104.47.66.40]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3ywn2aetcx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 27 Jun 2024 01:15:23 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=nNTMegbjJBZtgTVAROKurGiqenBaoW9mOysRUF4qXkw+bOsFojDQl4Xrx0NYB7h8jc/V4wd9fXlKJL/1xczF/0FPjlZ1G+1DvQhemcHaQSMxw6Sy+pY85t9etA/r4p9cUOq5hIBcUYbxmk9Bgyo266I1j/fMinu/I+esRPHCv9Eqn/xElnaYcbW3w0CRVxdkrO0fcZb635W/Z9bVlZEzSpIaFrQ3E5/D6eyztUk38d9QDrxU+bM/fHIJO5PhtQGNzjck1YiIkWFp/WjDS9lARBn0rHInex4SRKXSWBbny8+BZMQWUpMC2REXBxeklF0HRc1CRyGBXbniIcgr+5ohMw== 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=PmOqPQYXrPCu3EN02qEICToIuw23wCIT7mG8Mpz6TrY=; b=fWMa4zxjCmqr+kzaynx9cqEztnfi8OeuuEgfQ845bfsCj6xbJFG16oXi0U9poQAo+m1q/1i8LfNLI7ISd2jYsQSyG07jXnPx/Zlngmh9QhP8QvuLgbjBJhFvCeiJHj4bXuBh7GDyRahr7W39UbPBMJdTBwwLs3IGTJS+op/XVyvbTkr9Zt6fDiJno0bmg7ULAo5mFwJKbp8V3xG1cONHxiZs0AgyZulJWuDf4Z5lMCzdATDEeV2zvWU1JFMMt/3ngepQLpEZOekhheEev46Zp+uTtP+9+jeUiq+dUShkkILxK3t36EoyqKoqZy6rO3j7P2bB8Og71fZ29aXjHrsE/A== 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=PmOqPQYXrPCu3EN02qEICToIuw23wCIT7mG8Mpz6TrY=; b=JtmzMYJYnC8rMEMsK9On9P1sHz36/y34jtEeNCGj3uFIXtl1DyUEb7fgLkechp798ryqIe9dmnou/K99xxzKOyLeHnllyCLJ1zrgch4W2V4p9XMiRALV+iCmxmVNYgdaId4r/wfF19rkqj6cuvLCKD6Ii7uUpiOhFCS0vXh+XAo= Received: from DS0PR10MB7933.namprd10.prod.outlook.com (2603:10b6:8:1b8::15) by CH2PR10MB4216.namprd10.prod.outlook.com (2603:10b6:610:7d::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7698.32; Thu, 27 Jun 2024 01:15:21 +0000 Received: from DS0PR10MB7933.namprd10.prod.outlook.com ([fe80::2561:85b0:ae8f:9490]) by DS0PR10MB7933.namprd10.prod.outlook.com ([fe80::2561:85b0:ae8f:9490%5]) with mapi id 15.20.7698.032; Thu, 27 Jun 2024 01:15:21 +0000 Date: Wed, 26 Jun 2024 21:15:18 -0400 From: "Liam R. Howlett" To: Andrew Morton Cc: linux-mm@kvack.org, Suren Baghdasaryan , Vlastimil Babka , Lorenzo Stoakes , Matthew Wilcox , sidhartha.kumar@oracle.com, "Paul E . McKenney" , Bert Karwatzki , Jiri Olsa , linux-kernel@vger.kernel.org, Kees Cook Subject: Re: [PATCH v2 00/15] Avoid MAP_FIXED gap exposure Message-ID: Mail-Followup-To: "Liam R. Howlett" , Andrew Morton , linux-mm@kvack.org, Suren Baghdasaryan , Vlastimil Babka , Lorenzo Stoakes , Matthew Wilcox , sidhartha.kumar@oracle.com, "Paul E . McKenney" , Bert Karwatzki , Jiri Olsa , linux-kernel@vger.kernel.org, Kees Cook References: <20240625191145.3382793-1-Liam.Howlett@oracle.com> <20240626135855.a4b64612a9104ff163e30bd7@linux-foundation.org> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240626135855.a4b64612a9104ff163e30bd7@linux-foundation.org> User-Agent: NeoMutt/20231103 X-ClientProxiedBy: YT1PR01CA0112.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:2c::21) To DS0PR10MB7933.namprd10.prod.outlook.com (2603:10b6:8:1b8::15) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR10MB7933:EE_|CH2PR10MB4216:EE_ X-MS-Office365-Filtering-Correlation-Id: 4ff629bc-d786-4ab3-1ad4-08dc96469d3d X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|376014|7416014|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?VJUei2BkYXZmqaU36kPQwcmzdwwTTFnpLgRNpLr52/Ik9yuH1vX7clb2D+5+?= =?us-ascii?Q?jZNU+farRmZmONDSLxuhKwls0JirM149j9ypEilkKj14poY4bny6zYWCf84F?= =?us-ascii?Q?aUqUs9pqkxWmxh/SatL5dilBYLP2Zy7MqPlO+f4o96NgyvcAbjBxbTZL3pyr?= =?us-ascii?Q?/I68I9V/AG4R4YyI5y/L4OeDXO/PZLKuk4Y7nsq0qHqFbdUkrz7BI/lP8yB7?= =?us-ascii?Q?nzjZ9/ElCNzWYQOaAGGNr2rogEKdc75YECYAsuLkKzx83Yvf9AJU4XTig8xI?= =?us-ascii?Q?+fStF/VqIIS6+VHaCvga2x6tUdIMtiaQCFV+/Fn9jiswkyBjz2noq3RTrusE?= =?us-ascii?Q?T8bYXCztwPlWjMT4FRUUzyzB/c9ZU0IoSFRP58eax7GKS/16NyGUY/kF5g3e?= =?us-ascii?Q?N16lqyWVrwZ9IfFOMVNj7nh5vxUXshiYt/4drf8xAkrQz1YqIxT4g7zvMhBM?= =?us-ascii?Q?RE4guE9otK3dz9Hl88CSBkKJFwM0OA2rwtkmZhBcmOjS0Mx62Ne3U2vaRs4V?= =?us-ascii?Q?pVxRq1/vaArxiRkqyPFiFYzpglaEBja3uUIYXNLRdgtNKfpTKsR7qk7Laymj?= =?us-ascii?Q?TJar1WJPEbi1DUwwR4yqGIQZn7TwKb4HPI8uNOrZuhqE/gzdoq+5xBBW/75h?= =?us-ascii?Q?FCXpo/vIDUAZzljGiARqgDh/hF9fDAwFhgufxJ+SAOgdJbFy6Zn5M8A1nmhc?= =?us-ascii?Q?F+TQfeC4V2CTCLmMXMBfPhTr2LsqB2cycP6m2AK12LaVOYQ8kNhjD7tafPOM?= =?us-ascii?Q?5puDtwJfZe9tnsrwcEKvr5xiHtAWw6qnUrGV4/pK/ADq2xyvfBKLkhN3cKUx?= =?us-ascii?Q?aODLX//XqVB7E4pVd9zYZffrRdjk7pVDtmdfWSsvUEtlXdOM+48uyaa7JuiL?= =?us-ascii?Q?ZW04qfsPjQwlS65cI3k5zrsdL6hkxsEeTAlYNxDaw0d2zFdD+ybDSWT6Wzhr?= =?us-ascii?Q?sZSD4O85q+x3RGwCdRp51HmYnkpMM/ijuQNGzC+1fR2ZarEQq49NP29kJDye?= =?us-ascii?Q?F8Pi3rFyDuhQzR80t+fKfbOxT9huxrqg1XeX5vGhroMGw+44vRLUNYJ17nWJ?= =?us-ascii?Q?9L/RRjnRSUoXGzR8wkDy7J5jhAM2OIezBXwDryCrPMzdrCHw10x13HuEqyg/?= =?us-ascii?Q?zl4bvQoqJ2cW8VMsfPxYxvvzsiSo7iH/BMPSVXsBOP6jPoN1tMajl8YzcRxu?= =?us-ascii?Q?7G86h/rRYTym327PXxLYyRWEvNSisWYXp1ASd0LrssMw8IjtFIdXS1gYDnpR?= =?us-ascii?Q?+UtWiRrW1Na3/xSOP7lGCqZAzyLmfw4uIOI+XZs7fJbx34xTgNetpd2no6tt?= =?us-ascii?Q?wXmurH/uFEOwLA3o3mccPjGR?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS0PR10MB7933.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(376014)(7416014)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?vHQal/9qg84iVz32OZDGmBYpps+VZeiWQ/pXR40e1EUvCegdA1v3XwMyzSDw?= =?us-ascii?Q?hOQDij59mo3OF4T2/6mUV930deQDv5gVcmbCf4CXJaArMYeGil08I9SY0ztT?= =?us-ascii?Q?9z5ONUyOPA2CKhNHi5OPstGYYtb5Fg6CsckjHaEZEImeMpOPVACHhK3/tX9P?= =?us-ascii?Q?O88tRP9fBFbsAkqNPYp/dQW1vzbEBKavQbZ+YW+qI+T00tZ2dvAHw/Mrr7Zi?= =?us-ascii?Q?D0VJxV8mQhMmldIGhJ+lA1v71UMtrPhFmMVyF8pJ2UPhRtqxVkeQQk2FSKcj?= =?us-ascii?Q?kNiFbhrl1cIxK72lQ3eUuvS3DsVxo94Yh0b8NPwyOu9QrTMaSMzV/AuUmoql?= =?us-ascii?Q?7AUJmphEXcozVcPEpIm577poW/GBe+fLNsLDc6ihRKfy2Fe2NltKRG3/kotk?= =?us-ascii?Q?UBh2Ih0FG/MfUpjdv3NGC2s0wRScpXkrwxGMqNPFjy9B5ZixcfH24vqYT9Th?= =?us-ascii?Q?hU3cUqb+ByyeizZOnigUPjapqgtOTOJr13GyPVQzLWvpb0wOxknsrJcrHPDm?= =?us-ascii?Q?jngsJbvP/9APC1rG3jNPZ8NvZ6FrA1ugrJKxZdbTi+3LIpnpWZENvOM9DNc/?= =?us-ascii?Q?0fyL8J8IRnNmLJBbLukmgZvqO8xW08deRzzeYJdU27+yzy04FLNqAGSH6ctw?= =?us-ascii?Q?5xKqYYvQ4oiMFwCUClfUKTyjIJc393iWnyfwQnXkJb2gFs2DGrOkFpySGfwO?= =?us-ascii?Q?w7PG3SOvD3Gnt5Iquac/J6TS9Fy86/oX7IBSRUxmM8H1l3M7QFVD+Dw2LX1e?= =?us-ascii?Q?jFsdbQnRLHN2NbIPiGtwktyi6j5u5N5HNPQIPTtfLySbHcEoz9yQgCqrirP8?= =?us-ascii?Q?BQQ/xkpCx3e8AgUsO/EELwjUL1viR3eiZkYkuwp2S+FCp8swTuz8ZYIEBLpr?= =?us-ascii?Q?R7A/OO7/j1CH4yEh++mvicG8rHa+CkgsRKLeSI2e+T8yhbRmJfruF4oIxUlu?= =?us-ascii?Q?jhGvp7vWtDKU1Ml41Tzb8YLV1EV7IyGNyVqWL/ZLYf6QWnhdQ1xUL5lbrJpf?= =?us-ascii?Q?KTfDjNb9iQUYpryvk0a8U7d21MGEjXdw0R8Q0igPAqmNDUfH5Vom2Qd3mJkk?= =?us-ascii?Q?A3U2nzGAYvY/c/jtrPe+VCrT0IS6TrIohGVew8lczXSTaXAtoCEhGQY6Ltuq?= =?us-ascii?Q?UTGtR0RNnIZktOB6LerdElJWTy+aeSOlbfXZuu9zRHbv9GoILbynl9T2fGOO?= =?us-ascii?Q?KaNwCZgfUq+a1HpyxIUYA5IanWap6pjmbBnjMItGZzdHOzqThQGcMFw9F0WS?= =?us-ascii?Q?dGLugApvrRSk9wSc6dKUT1NA8wVFQrH8VwDCq1bRXzVXoU314GuUOmjr7VPR?= =?us-ascii?Q?5Fnhg2suFUksDjCyRZZOVSzyIiQ00m9gUlqlyX0Fjlpw6C9vd4IkLHx1xVr8?= =?us-ascii?Q?wdwC+17dmYan4a/JH28Cv3UcyLfI1+GMAwHSKLBJswHgSJ1IeGeI9Mfx86w5?= =?us-ascii?Q?lkHKI83PupYw3cGD0F04Zaf9k4dZXxHmNFMpg/qkdu7xKryXAqHBdvFN3ct0?= =?us-ascii?Q?8Av4pJgPGxbLQUcvdTrInUFyVBP/paahNWU+keV8tVMzWbOp+EMgA5AX7aOc?= =?us-ascii?Q?TIhnajZ5idR01HprMMMTqXXYBNHjN0gWvqpYsuev?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 4ff629bc-d786-4ab3-1ad4-08dc96469d3d X-MS-Exchange-CrossTenant-AuthSource: DS0PR10MB7933.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 Jun 2024 01:15:21.0851 (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: U+0PV3Rvy+drRUoa1L6gDWiQOw66sbgrBlNPAhQA6espIl/aZZKsQkT8dUPt1xhx89SFjAIFtHyvfkzIadtTBg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR10MB4216 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.28.16 definitions=2024-06-26_17,2024-06-25_01,2024-05-17_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 mlxlogscore=999 phishscore=0 suspectscore=0 malwarescore=0 mlxscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2406180000 definitions=main-2406270007 X-Proofpoint-GUID: NiMPqfkMq-0kCYjdpsncLXI3mrQ1OoXM X-Proofpoint-ORIG-GUID: NiMPqfkMq-0kCYjdpsncLXI3mrQ1OoXM X-Stat-Signature: 6k1dttso3rnni64ncm85557aoo84knp8 X-Rspamd-Queue-Id: 1238340016 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1719450934-110100 X-HE-Meta: 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 GzGjeypk 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 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: List-Subscribe: List-Unsubscribe: * Andrew Morton [240626 16:59]: > On Tue, 25 Jun 2024 15:11:30 -0400 "Liam R. Howlett" wrote: > > > It is now possible to walk the vma tree using the rcu read locks and is > > beneficial to do so to reduce lock contention. Doing so while a > > MAP_FIXED mapping is executing means that a reader may see a gap in the > > vma tree that should never logically exist - and does not when using the > > mmap lock in read mode. The temporal gap exists because mmap_region() > > calls munmap() prior to installing the new mapping. > > What are the consequences when this race hits? IOW, why do we need to > change anything? > In the (near) future, we want to walk the vma tree to produce /proc//maps. Without this change we will see the temporal gap and expose it to the user. This series was initially sent to Suren as part of his patch set. We also have the new interface for an ioctl request to a vma at or above an address. I had highlighted that an rcu reader would be ideal, but proved too difficult at this time. These patches by Andrii are currently not using the rcu reading method as this and a per-vma locking clarification are needed. Since there were two users for this code, I decided to send it out before the other patches. Thanks, Liam