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 C017FC87FCA for ; Fri, 25 Jul 2025 10:05:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5D08D6B007B; Fri, 25 Jul 2025 06:05:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 581916B0088; Fri, 25 Jul 2025 06:05:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 449636B0089; Fri, 25 Jul 2025 06:05:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 3466F6B007B for ; Fri, 25 Jul 2025 06:05:23 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id AE7F01DBAC3 for ; Fri, 25 Jul 2025 10:05:22 +0000 (UTC) X-FDA: 83702354484.22.A42528A Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf24.hostedemail.com (Postfix) with ESMTP id ED731180012 for ; Fri, 25 Jul 2025 10:05:18 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=e5lnG4gN; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b="LT/9MGxV"; spf=pass (imf24.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=1753437919; 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=RG1MWNC2RJMcKM4ehTOlV+1CM7EtHP+efLJj2KEaMc0=; b=RD+/WiJxd6n//gcbUGooaiUiBsBPkErCCi2K1JAe1PYJwJa+dxgPGFIDQL9dOkKlyySCe8 n+SPQHsfaygyYxchhjv2GSHoFXsEmASFvfcNCU1RvupW1UXwKzqw5Gt7jfKyiCZRHyjRV6 WQGtxh5rpx7c3+MPWaALocNawMrsmVE= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1753437919; a=rsa-sha256; cv=pass; b=nYdAdwX3d5J4NPuAXa2+jUP4hh+9zZnwtj5dnXM41ehSRYXEGQOqLOUJamvDnq5gY3lrp4 D/izlsQ+ypuQTkm89uXa0inNC09vPVbj9c1XxXx0QH+npIAVGXQo/+nKHFvSruP2XXbv8E W+FDFPrqEJIterlHhPrI/kDwf+uOmwE= ARC-Authentication-Results: i=2; imf24.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=e5lnG4gN; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b="LT/9MGxV"; spf=pass (imf24.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 (m0333521.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 56P7fsJE005951; Fri, 25 Jul 2025 10:05:15 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=corp-2025-04-25; bh=RG1MWNC2RJMcKM4ehT OlV+1CM7EtHP+efLJj2KEaMc0=; b=e5lnG4gNbmRq1LFNxx3bl9Ta1uXyPvlsl0 +Jyt8r7nrmPjq3SYFCrbykCMrcYLM1D5KtYqo9zskMw03cbw0dqzYhQQlFgJLtTo 4J1UiMHGf9RJvAH4eHOOfH8+/AFgfESS26sGhp59GEtvu09FY6/8xfzIcF83jG4K XWsPYgoi1E4scrFLFp083mPMbXz6xZovfAot9a7l6E/uuV3IqAo5CBbTFV8TbXj9 qhPkzsJiWqBvCcushIGMVxeNijMb2CDJUwS/EMLG+xhLtFApBq6ylRCNG3VOTp9N ei+IINpY3DqPCZv5VMr0GTJFPthzZ3BCKiOY12+lg0e9C1738Aiw== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 483w3vgs7y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 25 Jul 2025 10:05:14 +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 56P9cBJ6031494; Fri, 25 Jul 2025 10:05:07 GMT Received: from nam11-dm6-obe.outbound.protection.outlook.com (mail-dm6nam11on2074.outbound.protection.outlook.com [40.107.223.74]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 4801tk868y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 25 Jul 2025 10:05:07 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=NlEuiu5Ov3p1U58P2rDzYDmKFLC5YT65Sdapa2jmWg7NrCMohHUNU5dibg3bXHT8/gE79PsteUdgb9e9n4y9Sqt9iUnpiIdppVBJXFTTerjZMtgZNfVS9gW2fSBq6puhIPxn9ezGepMW3I0YCbBAEoVdNPGiZKE5LawbOGODsfpQxXBgoZ7Dv86HPjj6t7pvmU2YZQSzyBV1iv1PK+H2UtbmGD8g8/PIC2jJFgJn/v+2o1GfETOUhy2Na0RZCP6jTeNgiLi+gGg1z6vmUYKlBT4APoUbBGZuP0aVf7MYz5oU2QDg/WAgfnTJdl2fj5vaTm0bYeYqj37/C+YPwA8jGA== 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=RG1MWNC2RJMcKM4ehTOlV+1CM7EtHP+efLJj2KEaMc0=; b=H3Unh2S0YD7yQhctvxNpOTdRjMQBdF4YKXoU2xERg5Wul+TjntNX9ZiP2MHyHKNy4W8TUqDxHpjMKjPtzSzublZLRTWE53Kp+n/FIJj8F8eRSZikzopgd1vEmhtd+O2uTrvAumoMVfMSaeEBILuKj1cSedRQ6BjDtWNhQnUg9+DCoHPpv4g9NHXbrVHWJAC9koOt0dXp3hCEH8KIRbqLsDB+2nsMOl43eZHMu2BwWvIhThhgZYx4kx4TKgYpv8uvtjK9gmriT7PS7sK9vCeb1H1WDGahnZBtvB6zu+HYq4RKxnJsPWlGXZGQkZUlrat8vXDYdagiSuzluSkq1vgG5A== 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=RG1MWNC2RJMcKM4ehTOlV+1CM7EtHP+efLJj2KEaMc0=; b=LT/9MGxVDNs8DAUQrLsO1ccWdIx1fOjiYKeniINnZx7XJMcZUiG1IED/GJ8b0mxyiwFwv4/Rcl+MOB/IMCIAg2NqJ2zAiVFoqofwUfKIUB0uuHO9ZLzkcC7Tr9BOzOhD8RYNcsfADwJMYSQ3Fja8tUVhbXpfK8lej475pDfNT7I= Received: from BL4PR10MB8229.namprd10.prod.outlook.com (2603:10b6:208:4e6::14) by IA1PR10MB6781.namprd10.prod.outlook.com (2603:10b6:208:42b::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8964.24; Fri, 25 Jul 2025 10:05:04 +0000 Received: from BL4PR10MB8229.namprd10.prod.outlook.com ([fe80::552b:16d2:af:c582]) by BL4PR10MB8229.namprd10.prod.outlook.com ([fe80::552b:16d2:af:c582%3]) with mapi id 15.20.8964.023; Fri, 25 Jul 2025 10:05:04 +0000 Date: Fri, 25 Jul 2025 11:05:02 +0100 From: Lorenzo Stoakes To: David Hildenbrand Cc: Andrew Morton , "Liam R . Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jeff Xu Subject: Re: [PATCH v3 2/5] mm/mseal: update madvise() logic Message-ID: References: <4f66d89a-631a-43eb-b4f9-c9a0b44caaae@redhat.com> <692f9624-e440-4cf2-8202-861c679ddb73@lucifer.local> <0ad414a1-9a57-4050-a7b6-fdea08aebbd1@redhat.com> <507a09cf-291c-4886-92e7-9d9cc294a247@lucifer.local> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: LO4P123CA0038.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:152::7) To BL4PR10MB8229.namprd10.prod.outlook.com (2603:10b6:208:4e6::14) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL4PR10MB8229:EE_|IA1PR10MB6781:EE_ X-MS-Office365-Filtering-Correlation-Id: 992b411d-cc21-4462-4ef0-08ddcb62ba07 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?4yVTVvrXXOGLsPFp91qRthxrVieEscmFERdrPI2LFHO11DuBws0xO6a9tlah?= =?us-ascii?Q?GAm3LUnZ+TmXASbFUp31+UV5nFIhfbyelI0/5FfwuHMMPFGMqG6/yaMnq2f5?= =?us-ascii?Q?mzGSjQhTRlmZivCqd39CM5O8skeyrmGIrfbE12UV2TVCZHz+RXD5YEcBOOV8?= =?us-ascii?Q?tFotWpzeJ4PwzxqQzK5u+xC+HAknBbZnzdlY2dOd9pgmGiI5nU62i34ijSnk?= =?us-ascii?Q?OOu3ok3nlfE/ay3RUVEtOEUoykUbCuuTKZr4blpdLl7ceW2XyXJ+oVhAlEjF?= =?us-ascii?Q?Rj3yQBd/dzHD03dWozrEP3hkr9gcFCkx8PYtXHwSU+4W9nzFND3RRMo9zNOo?= =?us-ascii?Q?i+huTWjO4fr/5Iq4aUICcGV0ZFq3B405EbuHk414lMR/HtoMBF+1gU6TqOi8?= =?us-ascii?Q?V4LxwAkXaL+eSm0vbhQvTDvdAbplR6QmJsthd3kRAGgG4NKBAy2pKf6eeDMN?= =?us-ascii?Q?FQggF0sEIlXwGdOjezlFyKYYumDyqGGnqezVUcTJOGy0pkgUVX7gdajeiTiI?= =?us-ascii?Q?t7oaV9Mm6GdL78nJbrnIi8qTx64syGndNSJTxgaPFGDCFxRtPNTMj/6DcOFz?= =?us-ascii?Q?hTEnUQXJvV363Nk2Plh/fdNcx/dQZE7lQolpGnyySlVglYYpf37W7oOtWKDo?= =?us-ascii?Q?H14R0rHjg19cnnShWnJxIOm1kWAs7b2qyHO+Gi0STMWafvpgmf55BVDo7Osr?= =?us-ascii?Q?yxpU6pQ/6P1xp+cvE8PP8M0Tx3yE2WwIZCBrSCxotIX3XfsWr4vMHVgLaMmB?= =?us-ascii?Q?W/oH39gNzeRWrYcCTM3lxIwlBljYaGLPjRaxVB2GDG6Gl/mdCxUZlg0b+ksA?= =?us-ascii?Q?m68pje8xQgKIq3D/Aw0XHUCWJ/BKYjqCU+5EWsJU1a6RjUCaI61D80nb/IcK?= =?us-ascii?Q?x2PpUfSSy4EY1lZeDKCS6Cgcpl04OFyvZWr5ztQJSfZdTK1TfgFyhy145FZ4?= =?us-ascii?Q?nDpISfDyN2fFNE/y7m0l7UyjhUn/J9iJjc4c9VEtSQfe/RrnMELzUpszQDj9?= =?us-ascii?Q?Trb5RAjZW07nqSKO9vDGmQbD3Jn4fdQ2/qXClQW59KHriy28NjIE90ajWT20?= =?us-ascii?Q?jJSFc8mHhYP1p4d5VIxsN4haDzTer9LhLqhb1zbkGt0SrCV/eBkIfuzMu90L?= =?us-ascii?Q?rg/KbCmShxmCnOf3nY6v/Z8B7Jcd1jK2lLBjA5ayXnMXrqby+mxTZRvHX9OF?= =?us-ascii?Q?9lay7uPamBp13N4bTUUZZBrHJMcMtRQnNyxt5A/Xs1f2wPrKJqCh1QF2Awkb?= =?us-ascii?Q?m/p1RikCxS/4wMdxr1QyjMtl5ApJjAl5I6fc//MY5cE+NvH030NcJkPy42CR?= =?us-ascii?Q?hLeg8UCoH93T/BcNzF9Ur/YWDA8c4DcDQ1buozpfm856dcLh5QvyKaXwy8BJ?= =?us-ascii?Q?IA6+ssTWhpSf+gYJmafdaltWT4l/m8pxf0GWl00CroYCyXLg8dRZ7dQXckq8?= =?us-ascii?Q?bpv1bEyMSlk=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BL4PR10MB8229.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(366016)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?tnCMJ7HSXHp0bShyImhlxvMBYEayx18dx0vZBOrK9hp6MS7cTrusycBtOH4/?= =?us-ascii?Q?Jyfux7qIEQJw9J+c2Dy0KNIQ4nEF6IQMtT49LGGEdLF4S7UsphX6NBvs4yaA?= =?us-ascii?Q?5oE221+s4cy0MWzJQ5uife1hgkqJizYNZ6qdkW2e0r0YHR0YVGWClo4TcSHO?= =?us-ascii?Q?lZFzObhBbb6zOzHogC1nhwDu054PBRIf0YSp7D7FGC0KZCQuy9XkSmyN+bF4?= =?us-ascii?Q?L0MpU4o7+7EXLScH/NDLNx5SqCJ8tN7w+Lph0/GTfqV9CrI9sUCHUJbfA6Nj?= =?us-ascii?Q?FrifZLDr2oDtPot5zdg9D3bm/m3t3s4WgV278MolYEr6EM7GZhm8NkFpETSp?= =?us-ascii?Q?cIvnSbqZj8J7IcIK7fe/9nIyuOOwl0TBB1G4MEefh1WwKVQBwTv3dk+2jHBO?= =?us-ascii?Q?FAvdrZ/a7uhn4m53SK5KBxr9ZXL91+WyISEAII+89JGBuze+MaQFM3kDma7m?= =?us-ascii?Q?kXsVZ92aa7dWBZLfpv0aMOeCScXm72deu2+t07gmLYTf+4pKYHGXOIfgRhzw?= =?us-ascii?Q?hTm9H6On34iz3JFiBNbME2U5jbaoQBg+FvRRj954m48sdXyVJneVSBERywnu?= =?us-ascii?Q?W62JUDFWylRZo27uTq4gF3OyfEKorjewPjCQWoGFb7xBckjYt2fglT+HeuLC?= =?us-ascii?Q?6mxGvpgUN1rUMl6CgBiPpOJEmJwnjaOlcK5EZXQoH28ifqCc/MQ56NSzntso?= =?us-ascii?Q?/6rWHW/dpaPuB5mWgw8Qf8BbvaVUd+AjW5PkuM6K4nYge/j6a1OC9ibFTNNk?= =?us-ascii?Q?nzMcSvoQ6tcyr/DBbZ6hwUBoonr9r+6NfRXlxVCvi6L/Ctwsg0WnZosL7QbF?= =?us-ascii?Q?R6pon5nPQpMD2RXWg3bAaCg9E2pmm9HFTQAVgwER4hZPt0JDWpCosNAUkKcS?= =?us-ascii?Q?ZLJh0gaszeMotfsAkiJUpq9nOXiUmHydnXGTCaQGYqfBqfqU7BpoWq8brC8i?= =?us-ascii?Q?GmakundH25+IdkLZm8FJhEFJ+YRjE2DTTtKmCju2PMnTuuCnbX5j0fe6eIim?= =?us-ascii?Q?FM660W4KeddQElAFub5ystMs0f8N5qv/B3w2ntjsoD3XYM71t7ruVbhyhPjm?= =?us-ascii?Q?6gunhAwc0HdveC4a3tRW2onuG7LTY8TpsehDAymVCOTASnh5vpPRGaSPmggV?= =?us-ascii?Q?JJwpGWFTlRcmtTkRJM7gztNlGowT8R15CE/qRV7fU+G61wlVKkq00cuYcI4N?= =?us-ascii?Q?SiVRItGFTamwYqODxKIDx1lCOuDYVCPPewYya708wLZSE5wjZR8ZDlZm50zX?= =?us-ascii?Q?pMJ5RU+qG1HQymtAfwRIL5pwoEPpnviD28Tk7N0IvaO6hId/qodOHyg0edmv?= =?us-ascii?Q?MyGuSvBxINLRJtXtMD2sRP+c4CSmj28LwLX9Bfcjg6/HwegzjJT4DfRrfbNE?= =?us-ascii?Q?/doQVn9FDdwU25A2aV9YiSpwvJ8jS+kWqqH1d7smXgj8FIskxJc7gs0EcIC+?= =?us-ascii?Q?SYXf3ho7PEkw+AY+eObxvYH0AxVJKwh0VMIiPCix99bg1LhE7oCV+Gbq3X3c?= =?us-ascii?Q?36OHlOO0bG/jGsiG3nfY65jjp6U3o5OurixI8yd4xgRqnb07qE7JntFBXckA?= =?us-ascii?Q?YTYH86bCSUW6DVurGW4LcXtHKTOm+vfGRKeVwR26T5Zn9oqzGLvtDKHaigYp?= =?us-ascii?Q?zg=3D=3D?= 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: 992b411d-cc21-4462-4ef0-08ddcb62ba07 X-MS-Exchange-CrossTenant-AuthSource: BL4PR10MB8229.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Jul 2025 10:05:04.5438 (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: oqalH6CvFNFiHUYz3lQHlzHRtmGQ9A7VF15NJgFfoMGvRBM/8+1lqF5h5/mE/HeXUhK7rXKFLn5iSJfNrbl7fDjU2ZrKcUJcYEc1Cbq+cgI= X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR10MB6781 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=2025-07-25_02,2025-07-24_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 bulkscore=0 mlxscore=0 suspectscore=0 malwarescore=0 spamscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2505160000 definitions=main-2507250085 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNzI1MDA4NiBTYWx0ZWRfX1i8MrdYZe/1F PDChSFSxrB02fwsOhQU+myUydM1EdLj0LoZISLgjbxnGOxURAuvvnrtnTo46ECYuhEkVP5hgLIN XfIxKU6Dsy2btc7p4CbRvwoCiLy6U9Z6xXprLTgjoHwL1ITPiW26YMu5XjTRXtUrdW+sRgSj+zC nM3SAyp41WTq075Ns4bOiv+PYY9R25m+iRX4F+nGLD2eR7E8wIgBhcsRT5apTWMUuFbj7puvzaO XGPB6W5q/R1MYCM6g6hAvmoGNJoA/53ArY2Ag6tv9JheiNAH71RPOhxYJZ/iShPkvn4f2Nw2dJT 7Q/EgCNqD7djFR4vsrgjDOrsZwQmhhp8GXPi1Jh4ZH59GTdDw6Tm0OGtUqDPdFpSbzKodrIu4CP Zaa9ijt51Yq2j//9WwE3siZsvgq6tvh69/n0VrshMI4fIrClfrzqGqRTnLkHJoAKUthqztLn X-Authority-Analysis: v=2.4 cv=VqMjA/2n c=1 sm=1 tr=0 ts=688356db 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=kj9zAlcOel0A:10 a=Wb1JkmetP80A:10 a=GoEa3M9JfhUA:10 a=cA9CPFuHgmmAN9skUJsA:9 a=CjuIK1q_8ugA:10 cc=ntf awl=host:13600 X-Proofpoint-GUID: Fcb7xee8acEeWO8diAe2zUV1LSBei-CN X-Proofpoint-ORIG-GUID: Fcb7xee8acEeWO8diAe2zUV1LSBei-CN X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: ED731180012 X-Stat-Signature: ti4d9e4sfuudykrzfix19sd5ryx1hfcd X-Rspam-User: X-HE-Tag: 1753437918-459179 X-HE-Meta: U2FsdGVkX1/QJjnlWGuTn5uYJELZfePv2qUJpXVSCTZ5Ot79bp+ITVz4U5A75mfkI+1MLhRNAaZOhYcl/bVhN1t1Gdi+d8gJPKiVD5o/SbJh+xnmnU6H78Jg2j+CpJisc1D0mftyH4FhUZm9AWrL/Wk1ly/n042dMwkN8qexJ8NM8yYkrg2kr7Ncq0mUfoxaJYwW3SFtCZsVjSBrl4XVDxvdgWOLQT8xfZx6tHhyRHcEv2VDmJeqMQHpJB0DKUaAj0uX2yUBsnJOAhwypP9iPKQtBpAdtlraGg5h6m6/sEWb1eFeG+7BiObRC16faLzYOoB00TI/QA2JBa2sneJq0WoytfrYJCPzcxkcUQydI7o/ck9MuBR3cDKbeTT/ZftxQjJcSYIYbs3xyTiFcs8PQoeOHO0GeG21Vl4rTO6GhZFyfSYlO9OCkQ3c/rfrF33FpyjPYamE82BobJ60gVUXFgpI+aOwRUDIaVMiiosrjz1DaEpPkLE3liEqVIbeXCLlctfHoagVeEbAmGw1KMyFu/orccoL+J5mWYT2QdPzJDi1e/vo7aplXXd5xRBQ2sLTXXNdzwRkmNV/jWkbX81aULdMFCq30WFEsiWNM5QkUtd18vLvsfE2Q1/gfdo/1sQZIObdAWemr3wsk35y8YNO6OsrJEevsmcYlhIS3kkab2Hkqj0x35ImazOIa3I0hFnQ5RHiR/OrVJrcOK0jJXNn/a08OQC5lVEa0ndvKJe4jhZgYo4za+sAtA4G7Maz6fpXSN0WTQMrb4/bFGBH2Ep81P+4jo7C9Nd+FBBDh9sBWK4wI0+LZjd858xrfqIbnZ+Af2p+zzO6ZbkxgzErz8QQKQZR1ebMiKKBP3yGxc+Cbk+fBPq7yfuyJQNfD0LyVVbvu1c4WYkgAWrryrl4PirLtCIZXzB+Xue8+6hlzLCXjpPy4aUq2/JcG5E/wMmWoJGtyfvCAgX0g1gPgrPU3ys 4UMhPsEE DcB5ZvVwRZFeLOTUBzN32TqHol83Oae1aljVrvItg685zlotoFW2bzLbJLUR9P7gJmt5tOQ/eyEkxLC5b+ow69Sxm8qog03vBeSAm0qaVepy+qDYb5OA5NJ6YY0ZGRRaJKfLyaZtPH6OXCzvDy+5/v2ZOMhfoowFmq8HXmCx2OS01/Stch/R1oRtrQspQ4zpHiU6mkUEvuEt/SUCFQkrJmbp5BTSWdvyj+Hge7fCuVOyh9cu+bvNkmaQeryTrak6PX7kHuY0AXg2hQ8/e+YyN/n9UiEankk3+T+LTTedxlQ9PpZs3TxpVXzmtiKlJlau4mFts38IuCd4f4kR3R1CMCWSaSb7GM/VtF8EpTxMqSWVcgeTHHVyDXqm6M3UgkbWh6fRlXimzXDeET1fqHlIXwlUPHYiFNwpwZ02V+uSYAhXVrhTrKwCg6TCllAKE6wkC17r9LrUb0BetlhvK/aImWVcNlR9K8YNlZSdboF5P//IS+HvA2oATyW9fDZi/H/nDfP8wiXPNIQgz11zt9Amnh3VM12Dk134WXEKW7eLYfh+DBnFexgLU3+OQSi2Yf94ABqBeltN46rYMEOHnPreBr9vhR8kBEryFMPJKB3AwHJK9wspCPzMFdF/NM3zPzl1sbVEpFYZNIoxN19Ai6qpp1gDuWb2jmrxIoXfJZrsH8M3Ame0= 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 Fri, Jul 25, 2025 at 11:46:13AM +0200, David Hildenbrand wrote: > > > > > > Well, there is long-term pinning that can break COW and other weird stuff > > > like FOLL_FORCE. Most of the latter probably holds the mmap lock in write > > > mode. Probably. > > > > Well GUP uses read lock. > > Right, so it can race with MADV_DONTNEED. > > > > > FOLL_FORCE won't override anything as we have this check in check_vma_flags(): > > > > if (write) { > > if (!vma_anon && > > !writable_file_mapping_allowed(vma, gup_flags)) > > return -EFAULT; > > > > if (!(vm_flags & VM_WRITE) || (vm_flags & VM_SHADOW_STACK)) { > > if (!(gup_flags & FOLL_FORCE)) > > return -EFAULT; > > /* > > * We used to let the write,force case do COW in a > > * VM_MAYWRITE VM_SHARED !VM_WRITE vma, so ptrace could > > * set a breakpoint in a read-only mapping of an > > * executable, without corrupting the file (yet only > > * when that file had been opened for writing!). > > * Anon pages in shared mappings are surprising: now > > * just reject it. > > */ > > if (!is_cow_mapping(vm_flags)) > > return -EFAULT; > > } > > } > > > > With: > > > > static inline bool is_cow_mapping(vm_flags_t flags) > > { > > return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; > > } > > > > Not sure what you mean. Using FOLL_FORCE you can write into MAP_PRIVATE R/O > mappings. Particular useful for installing breakpoints into loaded > executables etc. Sigh. Really sorry, I'm having a terrible week, my brain just isn't working at the moment. Yes it proves the opposite of what I said, I misread it foolishly. Please disregard. > > is_cow_mapping() tells you exactly that: the only place where we can have > anon folios is when we have a MAP_PRIVATE mapping (!VM_SHARED) that can be > writable, for example, through mprotect(PROT_WRITE) (VM_MAYWRITE). > > A MAP_PRIVATE R/O file mapping matches is_cow_mapping(). Yup. > > > So - we explicitly disallow FOLL_FORCE write override for CoW file-backed > > mappings. > > > > Obviously if FOLL_FORCE is not set, then we're ALSO not allowed to get past a > > FOLL_WRITE and !VM_WRITE situation. > > > > > > > > > > > > > Hmm maybe I'll soften on this anon_vma idea then. Maybe it is a 'cheap fix' to > > > > rule out the _usual_ cases. > > > > > > Yeah, something to evaluate. > > > > I'm thinking more and more we're probably actually safe with !vma->anon_vma || > > !(vma->vm_flags & VM_MAYWRITE). > > I think there are possible races, the question is how much you care about > them. Yes I was just wrong. Please just disregard. I mean racing with MADV_POPULATE_WRITE seems a niche thing to worry about, and so what if you did, it's writing a... copy of the underlying file-backed folios no? Equally long-term GUP, assuming it breaks CoW for migration, is what, populating unchanged folios, so what's the issue? > > In case of CoW-unsharing, you're not actually discarding data, because the > page in the anon folio is to maintain a copy of the pagecache page (of > course, they can go out of sync, but that's a different discussion). Yes I know.