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 98D6FE77188 for ; Tue, 14 Jan 2025 17:56:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2E248280006; Tue, 14 Jan 2025 12:56:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2920A280001; Tue, 14 Jan 2025 12:56:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0BE99280006; Tue, 14 Jan 2025 12:56:14 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id DD500280001 for ; Tue, 14 Jan 2025 12:56:13 -0500 (EST) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 949EF1603E6 for ; Tue, 14 Jan 2025 17:56:13 +0000 (UTC) X-FDA: 83006811426.20.3781F0D Received: from CY7PR03CU001.outbound.protection.outlook.com (mail-westcentralusazon11022109.outbound.protection.outlook.com [40.93.200.109]) by imf29.hostedemail.com (Postfix) with ESMTP id 9298E12000A for ; Tue, 14 Jan 2025 17:56:10 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=os.amperecomputing.com header.s=selector2 header.b=rqcofqOj; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf29.hostedemail.com: domain of yang@os.amperecomputing.com designates 40.93.200.109 as permitted sender) smtp.mailfrom=yang@os.amperecomputing.com; dmarc=pass (policy=quarantine) header.from=amperecomputing.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1736877370; 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=bKu/exFWKWrIZV/0rAG5T11MktyAtd9v70ja6ilbYts=; b=HA3XPuNWPEcR5ljyHsmDAm93K//UbdO5mrhrA/DVoz8d5MRIfKD/0YwXSbDFkDQ+50yb6M 5fTGKO2qwefHbsxwR9upCB4WnHVjyARTBHtiW31q1ieZH/oObDeDsg7wkeI1UtMN97M9Qf x7DUx+30W7+kOobfQooWnnfYgS1i+Zg= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1736877370; a=rsa-sha256; cv=pass; b=itxwEgn/eq+w1moOtEfEn8ARO1UByryPsbgLnLdr7H97RCdnCRWhRnYhhmfp/iBYdx998C Xbx1njiFA2v5jjo09KiXjbmUegDe7ANEPTNgO9ugYTzofIJmm5XYLhfDvfP1ptWvRq64RI Kekbi56c9blJ+dYH28CsxwGIFo9ArRk= ARC-Authentication-Results: i=2; imf29.hostedemail.com; dkim=pass header.d=os.amperecomputing.com header.s=selector2 header.b=rqcofqOj; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf29.hostedemail.com: domain of yang@os.amperecomputing.com designates 40.93.200.109 as permitted sender) smtp.mailfrom=yang@os.amperecomputing.com; dmarc=pass (policy=quarantine) header.from=amperecomputing.com ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=qAMbTuZqPmZ6xjzfsVKXjh2HYldY25qnAD5lQGolzWF/WHcy2AtP4l26V70M9/29A+ttexUKgyoJkNG0leTynfXt6B/Ccm8WWWgAU6OjmgVQ3RKSf13ZvPZm5Y2SujNe3NbWTF2SPLfCqH8Okky8o4BRYEUzCBPVPe8l1yV2YCFyjvexMoilhmtyUosA7NUa2Z3/Znh15c06ejOQ8MSV2qGMBLBjGpFttIgL/X8ez5pgHAuBP6RYfliv+6zIZ0C43m95J5seohNqPVu4tAK5oJE+N4txoVWGnvfqh81dWjripgfw854+DdYiyx7XAkojHRjrbIjX9BBzTmCdG1gJMA== 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=bKu/exFWKWrIZV/0rAG5T11MktyAtd9v70ja6ilbYts=; b=YqjbM3w+Gk3WQSkqSw30hhBqDeYTHlUDyNC85J+VPjekR/0lLZAip4Hapm8bt++a7SP/S66LtpG+vrrLkUF3DfPhYXHrA5En4Q9FqNwr3scF178ETz5cAExHTuCdfuVq1E2Jwp+7usNQo3Xtu8tpN9YlQltzzVl8/7N6IUSTZyiVaq+yoFVg8iORzJzk+AXj1z03WD9YjHjyJ5jcwTwZD/NBM1qcWe3l+qDZQFh5+dKBPZHYHS1v/S2ia8hpSqDoBdVaTBlS/KR086Emdq1IZ5GEqEDBHdXK0tqKb5FefubRV6M20pFgD0uDU/np2jhbIUsDfdKJavazCzElwYjH7w== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=os.amperecomputing.com; dmarc=pass action=none header.from=os.amperecomputing.com; dkim=pass header.d=os.amperecomputing.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=os.amperecomputing.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=bKu/exFWKWrIZV/0rAG5T11MktyAtd9v70ja6ilbYts=; b=rqcofqOjWX02aMGsPFCmJsx+h27uUd6L3CIJslx14r62aTMM/rwdrQ6d4JW8JLld5mE8Z/arcF2brcuJZRI7fK/iPPcsenAsVfGD2gwA/3JkJAxML6X366d1ZDjoEGrt62oHg2jlJQm1Uj8nMeh8YeYzDfTEDpIaTummBKth0xM= Received: from CH0PR01MB6873.prod.exchangelabs.com (2603:10b6:610:112::22) by SJ0PR01MB7413.prod.exchangelabs.com (2603:10b6:a03:3df::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8356.11; Tue, 14 Jan 2025 17:56:07 +0000 Received: from CH0PR01MB6873.prod.exchangelabs.com ([fe80::3850:9112:f3bf:6460]) by CH0PR01MB6873.prod.exchangelabs.com ([fe80::3850:9112:f3bf:6460%6]) with mapi id 15.20.8356.010; Tue, 14 Jan 2025 17:56:06 +0000 Message-ID: <6489d0dc-175c-4186-a8eb-9250cac8aba5@os.amperecomputing.com> Date: Tue, 14 Jan 2025 09:56:03 -0800 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] mm: khugepaged: fix call hpage_collapse_scan_file() for anonymous vma To: David Hildenbrand , Liu Shixin , Andrew Morton , Chengming Zhou , Matthew Wilcox , Kefeng Wang , Nanyong Sun , Muchun Song , Qi Zheng , Johannes Weiner Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20250111034511.2223353-1-liushixin2@huawei.com> Content-Language: en-US From: Yang Shi In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: CY5PR15CA0194.namprd15.prod.outlook.com (2603:10b6:930:82::12) To CH0PR01MB6873.prod.exchangelabs.com (2603:10b6:610:112::22) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH0PR01MB6873:EE_|SJ0PR01MB7413:EE_ X-MS-Office365-Filtering-Correlation-Id: 81f91443-0f33-4e8e-0365-08dd34c4b85b X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014|7416014|921020; X-Microsoft-Antispam-Message-Info: =?utf-8?B?MXhPWGVGSjFlY3Vya1FIN1lob3lNYUx1T0VVbUxOMmZrSzN2aExwREN5bFJY?= =?utf-8?B?VEJYV3Y1b0U4bkxnYlcxejNvRWZ4VFpIYVNHUXg1OXBvbG1EM24rWmVLYytW?= =?utf-8?B?RzFoQ3pCZEdBVllJTklNeE05NzZRVHVabEw5STFxYmEyajVMalo2YVI1U0s4?= =?utf-8?B?b0xPVUxHNGxtVWNzekZqQ2RQaXVQQ2pvcU5abEZpYkE1V0xra1dCTVoweUJS?= =?utf-8?B?OHI3STdneTYzclc1UDFXeU5hREtHQmdyNi9nZExvV1ZvcG9zaVd3K1VJekFK?= =?utf-8?B?cXpvV3ozWlFGVHFSak4zVXRWcTIrV2xlNkMrV0kwQWZNc1lNVm5ORVpFYmlH?= =?utf-8?B?NXh2Y216VG4rM1k0NDEwWVhhSXhPbkJ4SU50eDhCZkxtRXhMNHVpZ09MVEJj?= =?utf-8?B?cVlNcWk4blhud3JaUVJWT1cydkhJQ1dmK2pKQXpSWi9ueVh4WUFTSGxjTGFQ?= =?utf-8?B?R1V2UDd3SllPYmV5MUE3blIydVh2NnJ5TlFxOTVkTkt1MzdJUmhMdXN1WndB?= =?utf-8?B?N0E0cFR5am5wUnpBMzZpTVJXa1plUEdQRVlZSklteVFuMHo4aEZraVFaY3Jp?= =?utf-8?B?dVg3ZFJzQkU4YjVIcVFNczZWN2hxcUZRd2l4TjhEQ0FtVVJaQzR1V2NCU1dT?= =?utf-8?B?S3A3dUdMcnl0cTJOckN3cGd5UFBGQmtnUWVxcTJYc25PM2xja3ZHaGdHdDNV?= =?utf-8?B?aVkxSEhxdU5LVnNCNTVrQVNmMTd1d3dIYmpJVE9YaVpua3BPR3kwMlF6RHlV?= =?utf-8?B?b1lsUVgySDRtNCswSG1GMzUzbjNHVUJDUERDWlRRMGtCMDk3bVdmR3BtSHN2?= =?utf-8?B?ZkU2b3pDRWVSWkd5MjRMbzJYbU5JMlRGUDA2YjkxaWpGUnBzeHdtZm5ZN2to?= =?utf-8?B?REJTTjRFTVcwZk14Y05saEQwcXp0aEI2Qy9oS21TczkyZi81d3ZoakNQeUFI?= =?utf-8?B?eXlTMDlGSmRHS1A1L2J5dUtQdWdsNjUzUVBtZUdaY2VnalFacEZaZ0xXMzlh?= =?utf-8?B?N3NpRVdMbEk2WXFtY2hLbGl5OStLWFgxRy9oeXZtZUswN2gvRDMvWEE2N0cz?= =?utf-8?B?dmZTNjN2aXNpSXJRZXU1TnN4YXlIQ253QmM5eUd2SjEwWG9wMkwzcWNCa2xV?= =?utf-8?B?MTNnZ1VQVnZsZmpHL0JHMXpUY2pmbmF0VE80ZytMaEJ4OXZ6d0N4OHhDV0wr?= =?utf-8?B?WnV4RTNJZ1R0bEtmcFBkdWRaU3NybW5HNWhZZExLVEkvK2Y4ZmpNeGpUdDV1?= =?utf-8?B?aWsrWlRQVWtRUHJ0LzdyVHF1M1QzY1A0eGRORlBCZjJwRG1XMWZLK1YrbnFS?= =?utf-8?B?OVZGem96WG9vbXY2SW1lVDNXZFpHMDBIcmFjQXRraENMUFJHcnVxeFFibXBw?= =?utf-8?B?L2tyazZmMGVJNVczQkpTN290L0lLSEg4RnFuOHNidWhIOWppZ2NkN3RtWUo5?= =?utf-8?B?VlJqTHlmVnFWQXEyd2djWEVUOVYrblpvZVVsY29XcGZ4VFNyU1F5TlBOWldx?= =?utf-8?B?YUlBcnBtWUJWVUhub2NRdkVVa24wQUYzdWkyWlZZYjVLMGdCMWY4V3pMYTBW?= =?utf-8?B?Z1g5aC9icHR6dVozajNpMXI3M3h0a3AyNk9TanhBbGxKb0hCUVdocGx4cHl4?= =?utf-8?B?dGFnZld3aXZDa0crN0pDaUxBMUpPWFQ4MXRLOC9tRkZnM0I2bmhKWitUWEM3?= =?utf-8?B?WnhGMU5SQzNSSEYxUExTT1lLNCs2di8vMU1rR3k5ZVp6c1F3N3lqS3VLZHhS?= =?utf-8?B?eDA1MFQyS1d2VHJCNlhpTFdaK2ltME9hdlZwVnltTkxxc1dsVmRIcWllMUR3?= =?utf-8?B?TGp2eHUzc2N3R0FBUGZ2d2xqbHZMRFU3eXR2dFVYaUpWR2FzL3Y0OWw1cTV6?= =?utf-8?B?ZlVPa1RCVlhKUmZMOEpKWjg0R293bFphcnJnTWUrbFhhOUluNHEvRGxyano5?= =?utf-8?Q?ZaZEHID7RP4=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH0PR01MB6873.prod.exchangelabs.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(376014)(7416014)(921020);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?c1AzZkE3OTNsZk8wN1FVbHFRcDVhajZsNmFGNWxEMjJmSU8wQ3RYbmF1end0?= =?utf-8?B?OUgwZFoyZzdyaHZaRUFOZzNOR0gwOFlaRkNyOUk0S09BSDhyQ2hvQllINFlJ?= =?utf-8?B?dHRTUzhCZXNIS2ZnMkVqZitScFJPa25TM0ZkZW5nZTdjRHM2ZDJYZ3NiUlRs?= =?utf-8?B?eFl6ZWtUWSs2cHc3dnRLczVTdzVreHVCNGFkS0lvaXA5dXdsSEJkcnhCNmVj?= =?utf-8?B?WUF4U1cvek1IK2lCTU5lb0c4NkcxSFRUeVhKRWcvdGY4MWQ5SEhNTWtDdkFS?= =?utf-8?B?NWdkdFprUTB3RFRkQzV3VlIvcStEVlZtQ1JXSnBoMTM3dmlSMC91WTh6Mkhn?= =?utf-8?B?WWdYVnZNa3I4T2hBcmhnbHdteGMvNlpreHlubGVleUszVG90eEhXWS9pSTAr?= =?utf-8?B?S2VJTnlRcmNWMHpIN1NrOW9kR0xmMnRDZ3ROc3dEQ1ZxUmhYc3BkNlFtdTZK?= =?utf-8?B?eGN6Qm5BRjM0QmhjVnFsUVRFY21saS85SmxlMEdQdkg4amxIOXVLR3hmU09q?= =?utf-8?B?YUZHRUgyRzdZQUdqMnVXZ1FBZ251TWd2T255NXVtUU1SUVdqRTlCeUNvdWpm?= =?utf-8?B?ZGdyUHhzUTh4U1dOUjE3dEt1NE5tS2loT24rRXh6bVcwRmNFcUN2d2VoMDhH?= =?utf-8?B?YWIzaUF3S0FWZmhFOGdTOEhteGF5ZnczU2d1ZlB5U2NxZ2J2a0JzL2hYMGJY?= =?utf-8?B?QVNLNE5RVFp3VElxRlJoTGx1SGlEVnBNQ1h3WWhjSElVcDVMTjNQWTlvaFI0?= =?utf-8?B?RThqOWhtZ20xVE43OTBZUHpPa3g5N28vTGZHd0tSbURGb0MzYnI0MUdMam5s?= =?utf-8?B?dE5pVjc1TTh3aGNJNjVGUjlpeTFDUzJXTWR2elRWZHM5ZW9QaWZocFlTVDNM?= =?utf-8?B?ZmIwZjhvMWZMSHpJME9GT284Um1UbzZjQW01d0lhcE9uR2xja01BNnNPZkZs?= =?utf-8?B?RGlqL092NWVjL2dMTFM5Z2tRbXlVTit0Zi84OWZCS1d3MlZpRUphYnZmTlhk?= =?utf-8?B?aW9QOGR6UFEzUENDUjZMT2tVRzMyY2dueFFSbCs2ZnpEcHE1emFvWWx1Qkpn?= =?utf-8?B?SUhXR1VTeWN4dXN2OXNtdVNablpzaWZGeTBCRHRnZU4vMTZ3OXFCaGpXZjJX?= =?utf-8?B?ZjRwQ0Z4OWdpMGg3TGRvNVlld1MzaWlzNXcweVV6RHFMRU9tU3pFeHA4aWJa?= =?utf-8?B?N2dBMk1mWUlyMjVRY3gvM2IvalMwNFF3MUZFcUx4aFk2aDBzUUIwOE9JLzc0?= =?utf-8?B?ZG9peUgvejBLdzl5UTBaK2NQU2hxbXZlR1c3TUNmV1FLVjlIdkF1eGxYeUZS?= =?utf-8?B?OFovaHI1aUZGdW1Ia3VhdC9rZkFYOGZ5TCtVY2NEU3ZlVlJWSEVxZWFpdGth?= =?utf-8?B?cTJyUVgrRlRSUnNlS0FvSnluTTVxS1NuQ2ZoZFRHZFp4VlJnWDlySVhZSzln?= =?utf-8?B?c0I4aXczclBSZnNoQjhmK3hTRUZBM2JBUjJTWXdJTkp1aEJRYnZ0OS82L0dB?= =?utf-8?B?dmpzRW02aFZxZDl2TkVNR1lueUJsdHp3eDlIMjJKRmo2ZDVJTVc5RnJqaUd6?= =?utf-8?B?VExFRXI4ZGI0QlUxTytNZHVMa0duZ1JkK3FqTm1TV0g4WmlGaDhVZzFGUlVj?= =?utf-8?B?OGhSRDlyUkp5ZUxCRDJSOFQ1SWxSZlkySnVWcExHeUFPaHVjeU5PMzZFQWVL?= =?utf-8?B?cjhtOTExOEpNU2JyU0dBN1B3am9UazgvdVFpWlU2WFFIY0c0M2hmSzQ2czZ3?= =?utf-8?B?RFQ5RDdUVzZhaFQzcm82aS9XLzBGRkNvek5SQmMxSzdRbVg3ZHZpNDNzM0Z2?= =?utf-8?B?eXZEeVN2akVobDB1SG00QUV2TFJoa2xUaUg3SVZ6WnZaYjUzNG5WSEczRVNs?= =?utf-8?B?VW1hcS9GWG5SbU41KzZ5VTZrVVR1RDZJSDRHU0t4eDhXRXdvcE9US3hGNlFo?= =?utf-8?B?elpHWllwSTRuS1FzSnJLVnZxWW9hYkNBYXpCZXQveVV6Ym5wbElqQ2pyV0Y1?= =?utf-8?B?aU56OGdCaHJJdXBmdE9ENkpGK0pEbnhIa3dyZVBXaWFlaDhWcVRZSk9nYTBV?= =?utf-8?B?ZmRSbkY1eGZXUlZ3M3puSUtPS24wcm00VTh6akFodE9UUWJkMWUyNFE3eGQ5?= =?utf-8?B?UmdnNlpBZGt0bUsvTnREQ0p1OFFvRVIrVzlzaUkvUWFicHRsekhwMk1oc0d1?= =?utf-8?Q?7Ozk0DLP24hXWki90tiHOM4=3D?= X-OriginatorOrg: os.amperecomputing.com X-MS-Exchange-CrossTenant-Network-Message-Id: 81f91443-0f33-4e8e-0365-08dd34c4b85b X-MS-Exchange-CrossTenant-AuthSource: CH0PR01MB6873.prod.exchangelabs.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Jan 2025 17:56:06.8975 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3bc2b170-fd94-476d-b0ce-4229bdc904a7 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: uZsyyyyXXsKmJ7+4vUyqPl7wvrepFHpA/DJR+zBK1VlAP88sqtlXOrzggJ+mHDlJBm4DmoLfrMosSUBmff0rPklXjQyowryDTjYGw74TLw8= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR01MB7413 X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 9298E12000A X-Stat-Signature: 1hrn8kkj5ticey447askdyhwyzy6ff5s X-Rspam-User: X-HE-Tag: 1736877370-782328 X-HE-Meta: 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 4Cfx5kd1 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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 1/14/25 8:56 AM, David Hildenbrand wrote: > On 11.01.25 04:45, Liu Shixin wrote: >> syzkaller reported such a BUG_ON(): >> >>   ------------[ cut here ]------------ >>   kernel BUG at mm/khugepaged.c:1835! >>   Internal error: Oops - BUG: 00000000f2000800 [#1] SMP >>   ... >>   CPU: 6 UID: 0 PID: 8009 Comm: syz.15.106 Kdump: loaded Tainted: >> G        W          6.13.0-rc6 #22 >>   Tainted: [W]=WARN >>   Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 >>   pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) >>   pc : collapse_file+0xa44/0x1400 >>   lr : collapse_file+0x88/0x1400 >>   sp : ffff80008afe3a60 >>   ... >>   Call trace: >>    collapse_file+0xa44/0x1400 (P) >>    hpage_collapse_scan_file+0x278/0x400 >>    madvise_collapse+0x1bc/0x678 >>    madvise_vma_behavior+0x32c/0x448 >>    madvise_walk_vmas.constprop.0+0xbc/0x140 >>    do_madvise.part.0+0xdc/0x2c8 >>    __arm64_sys_madvise+0x68/0x88 >>    invoke_syscall+0x50/0x120 >>    el0_svc_common.constprop.0+0xc8/0xf0 >>    do_el0_svc+0x24/0x38 >>    el0_svc+0x34/0x128 >>    el0t_64_sync_handler+0xc8/0xd0 >>    el0t_64_sync+0x190/0x198 >> >> This indicates that the pgoff is unaligned. After analysis, I confirm >> the vma is mapped to /dev/zero. Such a vma certainly has vm_file, but >> it is set to anonymous by mmap_zero(). So even if it's mmapped by >> 2m-unaligned, it can pass the check in thp_vma_allowable_order() as it >> is an anonymous-mmap, but then be collapsed as a file-mmap. >> >> It seems the problem has existed for a long time, but actually, since >> we have khugepaged_max_ptes_none check before, we will skip collapse it >> as it is /dev/zero and so has no present page. But commit d8ea7cc8547c >> limit the check for only khugepaged, so the BUG_ON() can be triggered >> by madvise_collapse(). >> >> Add vma_is_anonymous() check to make such vma be processed by >> hpage_collapse_scan_pmd(). >> >> Fixes: d8ea7cc8547c ("mm/khugepaged: add flag to predicate >> khugepaged-only behavior") >> Signed-off-by: Liu Shixin >> --- >> v1->v2: Remove the redundant vm_file check, suggested by Matthew Wilcox. >> >>   mm/khugepaged.c | 4 ++-- >>   1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/mm/khugepaged.c b/mm/khugepaged.c >> index 653dbb1ff05c..bad1e130eda8 100644 >> --- a/mm/khugepaged.c >> +++ b/mm/khugepaged.c >> @@ -2422,7 +2422,7 @@ static unsigned int >> khugepaged_scan_mm_slot(unsigned int pages, int *result, >>               VM_BUG_ON(khugepaged_scan.address < hstart || >>                     khugepaged_scan.address + HPAGE_PMD_SIZE > >>                     hend); >> -            if (IS_ENABLED(CONFIG_SHMEM) && vma->vm_file) { >> +            if (IS_ENABLED(CONFIG_SHMEM) && !vma_is_anonymous(vma)) { >>                   struct file *file = get_file(vma->vm_file); >>                   pgoff_t pgoff = linear_page_index(vma, >>                           khugepaged_scan.address); >> @@ -2768,7 +2768,7 @@ int madvise_collapse(struct vm_area_struct >> *vma, struct vm_area_struct **prev, >>           mmap_assert_locked(mm); >>           memset(cc->node_load, 0, sizeof(cc->node_load)); >>           nodes_clear(cc->alloc_nmask); >> -        if (IS_ENABLED(CONFIG_SHMEM) && vma->vm_file) { >> +        if (IS_ENABLED(CONFIG_SHMEM) && !vma_is_anonymous(vma)) { >>               struct file *file = get_file(vma->vm_file); >>               pgoff_t pgoff = linear_page_index(vma, addr); > > Acked-by: David Hildenbrand > > The whole CONFIG_SHMEM is all weird and needs to be cleaned up ... at > some point. > > BTW, do we correctly handle MAP_PRIVATE of these files, where we would > have vma->vm_file and !vma_is_anonymous(vma), but could end up having > anonymous pages in there? I think so. There are a couple of cases if I don't miss something: 1. non-shmem: khugepaged just supports collapse read-only opened regular file at this point, there should be no anonymous pages in this case 2. Shmem:     2.1. small folios in page cache: it should be fine to collapse page cache itself even though there are anonymous pages     2.2. large folios in page cache: khugepaged should bail out from collapse_pte_mapped_thp() if CoW'ed anonymous folio is met