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 D3ACFC83F22 for ; Tue, 15 Jul 2025 17:10:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4270B6B0092; Tue, 15 Jul 2025 13:10:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3FEDB6B0093; Tue, 15 Jul 2025 13:10:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2C6D76B0095; Tue, 15 Jul 2025 13:10:46 -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 1ABFC6B0092 for ; Tue, 15 Jul 2025 13:10:46 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id E39F71A00DF for ; Tue, 15 Jul 2025 17:10:45 +0000 (UTC) X-FDA: 83667138450.25.4C9E7FC Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf14.hostedemail.com (Postfix) with ESMTP id 4F83410000B for ; Tue, 15 Jul 2025 17:10:42 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=T8WWoJEG; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=P2hZh9TQ; spf=pass (imf14.hostedemail.com: domain of lorenzo.stoakes@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=lorenzo.stoakes@oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); 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=1752599442; 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=PgQ185ZDmyYs8N5Z0HQ7B1mEvAH6F3XK7f/p9xzs2Ho=; b=OsYfAgasm2uvbSWz20Kn5JkzI0aUcqqtYHhi2mY44c3jKoHtF11pKB0R7274X45VxtCX26 Hh3w5fz9Zcz1SDKsLkX2CSqLdGx1a9sgeuXMmP56+TqpjBiHMcH1tCfTwpe23pHb3ET8Um XqeRcXoMcj0f3cEXGdsFLZkB4JvBJOU= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1752599442; a=rsa-sha256; cv=pass; b=Vo2SLteESHfOycIq0Wpach/6AeT0r1rt/PWEC6FAMpBKzj/YZBkRfI9DBM3YWzeW8GZSUW yavL7irVZ2/OfgkV1IzMQnd0WdS028NnUdTYfmPNv8+e/N2LAXGihiFfBzUO/7VxyMNSET hxhpQTnXz0KhC5+WoJrwitBW66MgsG4= ARC-Authentication-Results: i=2; imf14.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=T8WWoJEG; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=P2hZh9TQ; spf=pass (imf14.hostedemail.com: domain of lorenzo.stoakes@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=lorenzo.stoakes@oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); 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 56FDZEN2031245; Tue, 15 Jul 2025 17:10:24 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s= corp-2025-04-25; bh=PgQ185ZDmyYs8N5Z0HQ7B1mEvAH6F3XK7f/p9xzs2Ho=; b= T8WWoJEG+KF0iZU25KneKK7xU8VXR/UVFEBZvG+4QMRMoaQ9xrdsOCmh3cCyHmU4 jz1RAMsQH63l8c23wz18g0wk6/X7rCJsr9LI8rAcXs8XwhFYg4wXFkcB4g7RrLL1 OzM2C4C9zWafS9djlFZwDCkczsns4NyahRNJouLi5CeTaeTPJH6WXICSVbAkMwej AAk1mz4Da4SYY1fdgwjux+/7/kxwfgmydMBtWUHEBc2UKy02RpiG8MpzqnW0B4tB vgX4qKV3K7jRgFSI+8cgg99zR4V981PlZU06s4U+xcML7qSNEvX9lPJGjZ0TN3jq Zc2z6s+nbh5kjszeNNU1PQ== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 47uk8fy7gn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 15 Jul 2025 17:10:23 +0000 (GMT) Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 56FH51cc040319; Tue, 15 Jul 2025 17:10:21 GMT Received: from nam12-bn8-obe.outbound.protection.outlook.com (mail-bn8nam12on2054.outbound.protection.outlook.com [40.107.237.54]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 47ue5a9hvx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 15 Jul 2025 17:10:21 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=Ve+8l1iqf2Y9YoBQoDG+O7Pn6ObAVvZ6EQG3LZ3tIMs4FIRJ4JvJYn+dF1jOh7GN1d7ilHKWi1p+oi1JIsoQkarv8iHWlRtLECsPGQY3rGbg0+RgO3tL/wduXDPdqTw4Mkb9LxI1AjbshY5/gh3pqntmSe8fW+v8fQMgXRAb6JHAZweZ29GJx7c7IHk1kVQp9Q6j62Kk7kpZOhx2sR4rWRgKOD8tle6XeHhAydZ383JP3gbmC4UL0/aK8WR9f3zBfq90DlqHGZCafw1bTirvGhJ1+qhJut3LldtouOk6+AXBMIVgm+JFp5BUeQk8n2bQQq2X7r9579X3hjLRxkhuxw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=PgQ185ZDmyYs8N5Z0HQ7B1mEvAH6F3XK7f/p9xzs2Ho=; b=TwoLcDjzPl+VDzFr0zaQt1Cxef5x+N8ct/6OCdGRUMZMY+teJKPw/tvBhjR/f3KakRGN+PLObbdvUijsabC6DH3r6Z9gISqn7296ahL0einMXvj+aUXUPrVB9R/tSxGb1waz9lovOWSBQwE4Lt/pD01c+/KGDWAcbkqSjYc4GPG11iU7pp9lGk9+Zl09XW81oDHWNqR7mXEMmKR38YfDOY5BtCpP0U3xL+SQzUUPnnlYJxrVX+0RPUNYMV4VRl/6P212SVk7wvQgfIHc/IyMytk0kt6JHNiZd+XAQsbm/hLxSAhXF1B4UTuiq/kRcaYvL1tOq1Gc0JpCf3ymLko87w== 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=PgQ185ZDmyYs8N5Z0HQ7B1mEvAH6F3XK7f/p9xzs2Ho=; b=P2hZh9TQf6eKIOW8CGHGN1odNxHfidmxFcMQtWqoYO8HiD2N5n+zsamZwEsgbCvBJ93Jy3OyRUbhwY3UURzK4y2rVozQn5NBS77sEzr9uuIl5830UKI4zlgV5bXKn7u8IHuIO9oFwVZDRXRWT52Bv1Bfg30b+HpPglokEDpP64g= Received: from DM4PR10MB8218.namprd10.prod.outlook.com (2603:10b6:8:1cc::16) by SJ2PR10MB7038.namprd10.prod.outlook.com (2603:10b6:a03:4c5::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8922.25; Tue, 15 Jul 2025 17:10:18 +0000 Received: from DM4PR10MB8218.namprd10.prod.outlook.com ([fe80::2650:55cf:2816:5f2]) by DM4PR10MB8218.namprd10.prod.outlook.com ([fe80::2650:55cf:2816:5f2%6]) with mapi id 15.20.8922.023; Tue, 15 Jul 2025 17:10:18 +0000 Date: Tue, 15 Jul 2025 18:10:16 +0100 From: Lorenzo Stoakes To: Andrii Nakryiko Cc: Vlastimil Babka , David Hildenbrand , Suren Baghdasaryan , "Liam R. Howlett" , akpm@linux-foundation.org, peterx@redhat.com, jannh@google.com, hannes@cmpxchg.org, mhocko@kernel.org, paulmck@kernel.org, shuah@kernel.org, adobriyan@gmail.com, brauner@kernel.org, josef@toxicpanda.com, yebin10@huawei.com, linux@weissschuh.net, willy@infradead.org, osalvador@suse.de, andrii@kernel.org, ryan.roberts@arm.com, christophe.leroy@csgroup.eu, tjmercier@google.com, kaleshsingh@google.com, aha310510@gmail.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v6 7/8] fs/proc/task_mmu: read proc/pid/maps under per-vma lock Message-ID: <7568edfa-6992-452d-9eb2-2497221cb22a@lucifer.local> References: <5ec10376-6a5f-4a94-9880-e59f1b6d425f@suse.cz> <19d46c33-bd5e-41d1-88ad-3db071fa1bed@lucifer.local> <0b8617c1-a150-426f-8fa6-9ab3b5bcfa1e@redhat.com> <8026c455-6237-47e3-98af-e3acb90dba25@suse.cz> <5f8d3100-a0dd-4da3-8797-f097e063ca97@lucifer.local> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: LO2P265CA0225.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:b::21) To DM4PR10MB8218.namprd10.prod.outlook.com (2603:10b6:8:1cc::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM4PR10MB8218:EE_|SJ2PR10MB7038:EE_ X-MS-Office365-Filtering-Correlation-Id: 20944b66-4045-4102-5f74-08ddc3c27990 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014|7416014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?WGlSWm9hK2tvblplMW8zeXBYUUYyUHNzM2pubCtIUld0cGdDV2wxUUZqMXV5?= =?utf-8?B?WGVtWktVTmdtWVJ0c3NXZnY1ZXc2REtyMm5EMW1qbHZFdDVXZWFJOTNjVG9F?= =?utf-8?B?aWZMMWx0MElueTFIdVdvQXpOSWhrTFc0UERBSlJBMVJYTDhCcVBmMnJyTUp4?= =?utf-8?B?eCtXVDVKT3kyM0kvdCtGMG5LQ01WYVlCNGh1VnNtTjNSaUJ5Um53WjFLZXU4?= =?utf-8?B?SndNVHcyOXVqbXZFb1RreHNUYkYxTlhpUWpsSjhJZjhiUkhtMVE5QWVNMVY1?= =?utf-8?B?U0RHemU1c0VYMnNURXVZaklKalVDMlQzdEYvenpCQ0ZMWFZWQUFKL3diMzVx?= =?utf-8?B?Qzc5eUNZWCszRUV2T3FNVzdEZ05lYVN1M0h1U2tzb2N2QlExaHd4clgyYWpn?= =?utf-8?B?VWFGcHV5Y3EydzlxKzRiMC9DSnRrQWdSV3VrbGU2UEZkaVVuQUdVVjVZYUJB?= =?utf-8?B?Rkdwd2RpREY5VlpacWM3WWl1UTVTQ3BqcmtIcU1USDlQQ0ZVN3lEQ1A4VnFv?= =?utf-8?B?MVl1VEIvc3JIQWJOK09HYXlXRm5sNDNuaXNJRmFPenRmVlZXU2w1TTN3WnpP?= =?utf-8?B?YWpMZmx6aUwzQXMyM3N0VTdQOU5DYVJzKzJTL2YxTmh0dDRpUXZ6WVQ2VWZY?= =?utf-8?B?K3dGWGxMdVU5WG92TXVwNGd3V2tVcnRWVXpHdmVyYXdlKysvdHFqcFNsV29X?= =?utf-8?B?ZzQyNWRTNml5NDYxQ2N5MXZ5bGxJbUhEejRPRkt5dkQyLzFtd1h4KzFQU3F6?= =?utf-8?B?cFYwaTIydXNNUzhNWUNCdmU0UHBkNURLeWhiaFl3SW1HOTA1U1ErNStLcU40?= =?utf-8?B?a0FLSk1tTzZoUU1KUWxIYnN6emRXVmp6bTd0SlRGNHhLSUNOcnhSSjArdVU4?= =?utf-8?B?cGpmQUNIdElCQUZiMWNkTUFvK2RVOEErbG1BSlJpL2ludDdMSnYzSjhSTkd0?= =?utf-8?B?R3hOd3NCenQwbjB2UnU2VEtrYzYxNmNuR3lzWXljV0JuOXBqTEx2Nkw1V3pO?= =?utf-8?B?NnQ3b3d2dTMzT2w4NHpsSCszT3dLQ0I0emNyS1YzODB0aUJudmNIcWN1MmZH?= =?utf-8?B?WjNYQ0doRXdoZjg0empEOXQ0NnB4c2xMbXM1RGJCU21JRVVRRXc0ZnBKYXRZ?= =?utf-8?B?Q2o5bmt6QkUyaDRpSHNKLzJSYjA1SnhhV0xKcHRqeHVmWU5tOWc0SGlHK1Vy?= =?utf-8?B?Z3NyTDVJWTZDUkVnNDNHM2NOUDd0MG9DeSszeHNzZk0xYWhxYmlUN0c0OFdN?= =?utf-8?B?SStCTk0vTzBjVnJOcUtvL3BDU0wxMHI4cjVGZlpPNUs3SWNQT1BhWjVoQVFN?= =?utf-8?B?TDR0OU1aNG5XTTZhOGppSHd4RVh2dkI5N3k1ZFQ2OHRMdTdJTGJ1OGJLTkh1?= =?utf-8?B?a0hsU0t1eUwvOU9JcHRkZU02QUZUTEt0SU9NWnQ0ckc2M1EvR0tDWUZrWUtT?= =?utf-8?B?VnJNRUF0Z2RQTFdZckNZc1pwY1NMbjZhd1c1WVcwcmFtTUNXRlFNNWZGRHEv?= =?utf-8?B?ZFdwaElrdXFjdFVxTHVVM3dKR2w4aVhPbElteDFjQXVvNlZWMmdzczQyVUNu?= =?utf-8?B?bmljejJvNnljc2UweHplNGdyeS9ueGZ3ZFRVTGtQWVV0anIrZVpPcjVtK21Z?= =?utf-8?B?L3VJMFMrdk54MTdGTkkzdk4xL0VlUUhEWllHQ3hXZUZCYWs3U1BLWURPeEpR?= =?utf-8?B?enpzRktlRW5kaFdLbnlmWkR0NFJCNTRuZ3hEWnBXY1dUVis0eUZEWlRtRVND?= =?utf-8?B?aTV4MW5xMUNBUjlOcjBKZ29uU1Z5MDRteGFoM2dqd0xoZkdMTjhDSU9HNlRK?= =?utf-8?B?K0MwaWllK2JkSk5lYURhZHU3Q2NjS2pOanRUbTRoRjcyYnd0aE51akVUU3dO?= =?utf-8?B?VEQxWnJKT0h4b3U4UUJzMTI0dVh1M0pyeUhFYmR4dDNYTVdZWU9uVzFLcDNr?= =?utf-8?Q?0Zhu+fg4Fl8=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM4PR10MB8218.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(376014)(7416014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?MTMyZXo0akJ2RkVKOGRMdXNMTWZXd1QrWDkyV0I3cS9KdFpoZHFaZHpreTBa?= =?utf-8?B?ZzRKRHhocmxFL0RWSjdMZ291ODNCYnk3OGd3Wi9IQnA0YkdROHpPMXJIWEhG?= =?utf-8?B?MEZMaWExbXU4QktIVm04R0MzMm1NNk8wSEhlZVVXOUdrLzlWbUN5ejhtZi9D?= =?utf-8?B?c3diNlFFeFhzbjEvMG5PTktJc2ZUT051MEFYSEJvRXQrTlBLUDN1OHgyY0g5?= =?utf-8?B?RnBPbk5pa290UWZVYStlSW5oSjNzaGJQOTRMK3lST1JQaGxWZytBNC9oNjA5?= =?utf-8?B?NjJMZEZZV3A0ZTFna2RwY1BXV0w4SStQc3N4MDI1TVNpN3gvVFdvQXc0cDM0?= =?utf-8?B?OUpQSGVqWFYvaC9WWUFuNTE3L3V4aWNYcTdDQytYNHlycG1lcE50THRPYVBW?= =?utf-8?B?c3Y2TzdZU0FCZ3Y1SVRIMEUyRHh1VElBMkxGUWJCVnpIYjdMNzBxbklQRXFi?= =?utf-8?B?cy82V3gwQ05LNXZRN3JSSWE5TUYzMkhtaFY0bG1sZXRKVVFQeFBJTHhIU1J3?= =?utf-8?B?QzFGWmI4TS8xcDZIMzdDbCtSSDRqS1JwUmx4OHA5L2JxMEtqckpHdWlzUGk3?= =?utf-8?B?S09DVTZXQkc0ZzkvdmhqNFJTU09OeGxoUUppRFlnL3VPSFM1YmtEMnJ5TVVB?= =?utf-8?B?ZU9PZVVXeUdxdkFMZHRnbmVzSWtnOVFFMmxTZ1g2OVVwd29DbGtpZFlWZkpN?= =?utf-8?B?c0JCOHg3QlJMUFBMVW1BazlFQUtYY1ZaZGErVE80NUVBVXNoQmlkTllNcHpx?= =?utf-8?B?dnF0VGtHYzE5RS9XZEZGam5RWUppTlo1Vk15cjBleXJud0dYMjJsMEVHQjRi?= =?utf-8?B?dTVXM1NQbmgyM3haTkhnVFpXTU4vQUY4LzlMZWR2eUYzY2FmVkIxVlNuME1T?= =?utf-8?B?VnlDRzl6WHhrYXBOOWhja3NUYnIrNm54VG5lNERlc0xJN1greXNXNTJ4T0VR?= =?utf-8?B?Z2ZkNEhQRmhncGdiQitidktpckt6a3Y4NytUd0o2cGJKZzVPU1NrRjlXVWwy?= =?utf-8?B?b05JS1ZiUmhDdUVtZG5PSktLS0hSQ2J2SnRtQ0lLVitpdE5uS25VcTRJSFhD?= =?utf-8?B?YjVIY0pBdGx6N1ZKVmJrZFRkY3d6d1N0cVZ2aE5menVjVjNLVm5DWVE4T2lj?= =?utf-8?B?MllUUHpPY3pScWMySXFEMUFwYm5pRm9GUjB0QzZiTkI4Yndpb3QySjRYT0dE?= =?utf-8?B?S2VRTE0wTjFHNzBLc0U5QW1ZQU03akNseUdINkdIMTU4akdsTTJYWkxXOVY4?= =?utf-8?B?RWhzeDRzeG1JVWIvc1g1MnFaNEFIN0tPcDFTcDZtVlIyRFg4d29rMzF6dHFX?= =?utf-8?B?RWtxMTBhc1VXTi9LbmRDUkFMZCs0QXRoKzFXcVpDdEJJSkZTRENmUUdpVTF4?= =?utf-8?B?V3FVTmluYVhZQXJUVExDenRYdyt4NVo5cHRURjVxYllITEU4YXBRdkhCUENt?= =?utf-8?B?OGZ4L0FPNmVZTHMwWWc0cHM0UFN5eFdRRjNBZFNKbm8wUjJpVXF3N1ZDWWZS?= =?utf-8?B?d0Rscythd1N4WW5TQXRCek9CZ3M0aGdhaXJxbGU2ZXNZN0pQYnhCWGpQbm5D?= =?utf-8?B?Slh1clR3V3Z0Y2lUNXR5VG93bndLRnIyeGY5enNzYktUTGF5Uk1EeStDRm95?= =?utf-8?B?Nm02dFJHTmorQTVhL00xUEUrQVlnTUErUkNyT1ZNaENZaWQzcG9qNCtYMExX?= =?utf-8?B?OXc2ZlE0VXltOUtkQjAyL3lCWUJ3VnFXQUdPTFB0c1hwU3pMa1dLSXBuQ1I0?= =?utf-8?B?bEhEZmpjK1c5RDZQTGtycFF1N0wvczZUOUVKZVpFeWZzOEwvYzU0MW9EUDNu?= =?utf-8?B?eXFLN091OFY4d3JValNxVWV1WStzZ3N2K0ZkL3VzbXNNWmxnRllFaytURkc5?= =?utf-8?B?S3RaUldQdFVUOXliK3hxTmpaMFRhSjhxMFJlUTNDOFNCYmt2RFV2b3Z4VDZ5?= =?utf-8?B?M0tmOFpoWmwrYWFJck9wR2w1TTV0Nk5Hdkhzcmoxd1VZQllhelhUNVZybUJG?= =?utf-8?B?Zy9jSS9BbkdtQjVwUms2RmFhUmpQVllwSXY5TmNkcmltMWlrVWduUGJ0M0RV?= =?utf-8?B?akxhRGo0TFJzbGIrMzBGaVBaZ1NQWklLMm8zcnlJWjNKQzU4U3pKVkJvN0tJ?= =?utf-8?B?ckQ1MXg4bUU4dnA5UU92d0kyU3BDbVBza1M5N1VoVzQ2UDE3Y2pTdGVqOUg0?= =?utf-8?B?cGc9PQ==?= 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: 20944b66-4045-4102-5f74-08ddc3c27990 X-MS-Exchange-CrossTenant-AuthSource: DM4PR10MB8218.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Jul 2025 17:10:18.7884 (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: WEbnaT/eTy/iGNkB9q+1ODMtWQnHYkoyTyJl+2iid8W66DZTKL+xdz844Jcq9VeCKKqkI0St8k54EdFyrWMgRgLBrMTDK6lE4PwLsp5vFd0= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ2PR10MB7038 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-07-15_04,2025-07-15_02,2025-03-28_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxscore=0 adultscore=0 spamscore=0 suspectscore=0 phishscore=0 mlxlogscore=999 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2505160000 definitions=main-2507150157 X-Proofpoint-ORIG-GUID: 7APz-HOXYJm-fIDUlKMjcJx3T8NGUGaO X-Authority-Analysis: v=2.4 cv=Of+YDgTY c=1 sm=1 tr=0 ts=68768b7f b=1 cx=c_pps a=e1sVV491RgrpLwSTMOnk8w==:117 a=e1sVV491RgrpLwSTMOnk8w==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=wKuvFiaSGQ0qltdbU6+NXLB8nM8=:19 a=Ol13hO9ccFRV9qXi2t6ftBPywas=:19 a=xqWC_Br6kY4A:10 a=IkcTkHD0fZMA:10 a=Wb1JkmetP80A:10 a=GoEa3M9JfhUA:10 a=VwQbUJbxAAAA:8 a=yPCof4ZbAAAA:8 a=rmMUEn68dzajLPKR-tsA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 cc=ntf awl=host:13600 X-Proofpoint-GUID: 7APz-HOXYJm-fIDUlKMjcJx3T8NGUGaO X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNzE1MDE1NyBTYWx0ZWRfX+OI2rnfxrj+8 0DoZW5R+vbnGwISZvCo+L7rsBQA3HEjfJUqe8f8mxn2jmPnnH+jyP22j+JuQabRCa/RNQ7eH6wB cg73rg6DaLQVTLVrDHBdSHUK6gMd4/gscndPUhCXUjuIeTW/6dkKQqnc+u5/clZGkAGRMgpm06C So9VqiIlBvAKbxYFSyeLj6ASzMgqCh8OZ/8tuF+XuSIt2K9fsvk/aWKyy39ndbDqMbc0aAFhc35 0lZbsbmXNIuoY2riwuGOhZxGWpDPx1dYfDYYo2sPg2c5cnKBBXKyblCgxHfBL1vwiVYm2dg+0PI FfQcx74w43bQqPyel6XyXPrcpgL9PfZRg77px+XSldV7SjRaEo0bbAPk4PGPlOYWq3hBjz4NKwJ GGuwI0PHRaZThbVLTjnMfOreCueMuy1YlDPbBFZqoWYftFQHvKZ+Asoz+EjIRaYYioz/3uUd X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 4F83410000B X-Stat-Signature: hp9kiy8kuyfrfskp7cch8uwjpxx5kdkz X-Rspam-User: X-HE-Tag: 1752599442-490375 X-HE-Meta: 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 FcKrnb1J 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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: On Tue, Jul 15, 2025 at 10:05:49AM -0700, Andrii Nakryiko wrote: > On Tue, Jul 15, 2025 at 3:31 AM Lorenzo Stoakes > wrote: > > > > On Tue, Jul 15, 2025 at 12:23:31PM +0200, Vlastimil Babka wrote: > > > On 7/15/25 11:52, David Hildenbrand wrote: > > > > On 15.07.25 11:40, Lorenzo Stoakes wrote: > > > >> On Tue, Jul 15, 2025 at 10:16:41AM +0200, Vlastimil Babka wrote: > > > >>>> Andrew, could you please remove this patchset from mm-unstable for now > > > >>>> until I fix the issue and re-post the new version? > > > >>> > > > >>> Andrew can you do that please? We keep getting new syzbot reports. > > > >> > > > >> I also pinged up top :P just to be extra specially clear... > > > >> > > > >>> > > > >>>> The error I got after these fixes is: > > > >>> > > > >>> I suspect the root cause is the ioctls are not serialized against each other > > > >>> (probably not even against read()) and yet we treat m->private as safe to > > > >>> work on. Now we have various fields that are dangerous to race on - for > > > >>> example locked_vma and iter races would explain a lot of this. > > > >>> > > > >>> I suspect as long as we used purely seq_file workflow, it did the right > > > >>> thing for us wrt serialization, but the ioctl addition violates that. We > > > >>> should rather recheck even the code before this series, if dangerous ioctl > > > >>> vs read() races are possible. And the ioctl implementation should be > > > >>> refactored to use an own per-ioctl-call private context, not the seq_file's > > > >>> per-file-open context. > > > >> > > > >> Entirely agree with this analysis. I had a look at most recent report, see: > > > >> > > > >> https://lore.kernel.org/linux-mm/f13cda37-06a0-4281-87d1-042678a38a6b@lucifer.local/ > > > >> > > > >> AFAICT we either have to lock around the ioctl or find a new way of storing > > > >> per-ioctl state. > > > >> > > > >> We'd probably need to separate out the procmap query stuff to do that > > > >> though. Probably. > > > > > > > > When I skimmed that series the first time, I was wondering "why are we > > > > even caring about PROCMAP_QUERY that in the context of this patch series". > > > > > > > > Maybe that helps :) > > > > > > Yeah seems like before patch 8/8 the ioctl handling, specifically > > > do_procmap_query() only looks at priv->mm and nothing else so it should be > > > safe as that's a stable value. > > > > > > So it should be also enough to drop the last patch from mm for now, not > > > whole series. > > > > Yeah to save the mothership we can ditch the landing craft :P > > > > Maybe worth doing that, and figure out in a follow up how to fix this. > > For PROCMAP_QUERY, we need priv->mm, but the newly added locked_vma > and locked_vma don't need to be persisted between ioctl calls. So we > can just add those two fields into a small struct, and for seq_file > case have it in priv, but for PROCMAP_QUERY just have it on the stack. > The code can be written to accept this struct to maintain the state, > which for PROCMAP_QUERY ioctl will be very short-lived on the stack > one. > > Would that work? Yeah that's a great idea actually, the stack would obviously give us the per-query invocation thing. Nice! I am kicking myself because I jokingly suggested (off-list) that a helper struct would be the answer to everything (I do love them) and of course... here we are :P