From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from CWXP265CU008.outbound.protection.outlook.com (mail-ukwestazon11020078.outbound.protection.outlook.com [52.101.195.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A9F0B1D6DA9; Sun, 6 Sep 2026 13:02:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.195.78 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788699731; cv=fail; b=tjIS+P1O8aPM8DoVwoimV0xPnnE8Dtqg78TwKmYuOWi+TewHkIlzmpdzhLZ2MPE/uVh+MqDDVJlp9T675jzGVq7L7BtP2RddcW7SatZBvp+a8/ilClFVpWIfumE/kyEBL1gCIdt3WsHsf4KypnEhZEuu9RQbjocSba9WDPHphc0= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788699731; c=relaxed/simple; bh=NxRsnhzxJWN2qjAlaz63JgBPlPN0uGq2YYM2kzQ6reM=; h=Content-Type:Date:Message-Id:Subject:From:To:Cc:References: In-Reply-To:MIME-Version; b=CEaoRpUsu78zrwtxO0AGm+mAHDIreuMzOkmFWNTlaE9NtsywpioNMaIObhVZ6pg6N+UwrWE/CZ+/f7TuUPNJjq6m0TXq3OKWaBq1cANHMrlXFLxHpAQHG8zcfp8rKj2Moq9Ic+T/Wys2cHvQoRb6kpjRZGqza+TGP8sMJ7Df8FY= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=garyguo.net; spf=pass smtp.mailfrom=garyguo.net; dkim=pass (1024-bit key) header.d=garyguo.net header.i=@garyguo.net header.b=xKYOvs7g; arc=fail smtp.client-ip=52.101.195.78 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=garyguo.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=garyguo.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=garyguo.net header.i=@garyguo.net header.b="xKYOvs7g" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=uQVqy+M0uVhT5ynteeiQ3lKchUaXYVU3FPnJjiXMv5SvUtDXi8jTtGJf4bgToXeLRJ/4eESX72gh/TqLEQMXwEDyOe3Cc12uJFERefYa75enkgchOW78IlXHgGM2XjzcBL+5tfcO/N3gmRS/qtT2LLIzBoLHvk+6oFRosd90XnI0oZdeMDZIpu3rMNVZ8ODPqE6XREzxRMcgY6njDu3R/1HbmFYv1EopTapUixOOMZz4gkMobyn1ZRd0zrQan015+4uOwfk9wVZzz73sfIeTDytE+WaQvVfhYjlT+9xxgaaRRilXd2kmlSuZTcpn8gsIikkdSW4P8rlGCS0pBX5Ruw== 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=Z5sHOADaRnb4q6ggfAZo5w0PFsTjdXn0aCEfA1hegTU=; b=R7T5ugPbZo1qJP9fGmNOolgyjtZ2N6P8/JmGS9AJ0pTmVX8mEMU7I0ltKIkGpOowH0GHnLsdHnp2ggFPAm4KmMuOx3f2aQEXayDJmgTOd3KahN/yH/8gwdR1Nd4+gHioDZ+FtfC90jfDAzVuft6DBI99JGJw0vGXoP+SK5nVeDxtf9TJ8+BV+5/sotyiWzO4NCu42fYEQt+yhR+uWLFR7Ed5BM+RSEp3Jcckp5gZ/TaR3cPbmLNBmMXK3ya2Vl9p/qgQw4BrNnN+W1hsyawRO3ymkw5Rdkxvn3BAL37AFs0qa+3igvivc+WZVPizqrMp+2SJBUHLAowbWceaM1ag7Q== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=garyguo.net; dmarc=pass action=none header.from=garyguo.net; dkim=pass header.d=garyguo.net; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=garyguo.net; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=Z5sHOADaRnb4q6ggfAZo5w0PFsTjdXn0aCEfA1hegTU=; b=xKYOvs7g6y5D5MZ5R27QLvf29Ko54FtUx+Dzkp25bgN08q4GgbU3LRJLmoJRdI8UySTHimMB7ODvY32GJHKRZxhXHw71GsrbSayQh/WbQkhJYYmtRmgIKuT7OUD+1Odb8Lzo1x6FWoBoix+V/lryYRHdPiR8smWrUyIYvqIu2u0= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=garyguo.net; Received: from LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:4ab::19) by LO0P265MB2635.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:14c::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.382.15; Sun, 6 Sep 2026 13:02:05 +0000 Received: from LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM ([fe80::f60b:1537:68d7:4fc1]) by LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM ([fe80::f60b:1537:68d7:4fc1%4]) with mapi id 15.21.0382.014; Sun, 6 Sep 2026 13:02:05 +0000 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Sun, 06 Sep 2026 14:02:04 +0100 Message-Id: Subject: Re: [PATCH v20 4/8] rust: page: convert to `Ownable`' From: "Gary Guo" To: "Alice Ryhl" , "Andreas Hindborg" Cc: "Danilo Krummrich" , "Lorenzo Stoakes" , "Vlastimil Babka" , "Liam R. Howlett" , "Uladzislau Rezki" , "Miguel Ojeda" , "Boqun Feng" , "Gary Guo" , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , "Benno Lossin" , "Trevor Gross" , "Daniel Almeida" , "Tamir Duberstein" , "Alexandre Courbot" , =?utf-8?q?Onur_=C3=96zkan?= , "Lyude Paul" , "Greg Kroah-Hartman" , =?utf-8?q?Arve_Hj=C3=B8nnev=C3=A5g?= , "Todd Kjos" , "Christian Brauner" , "Carlos Llamas" , "Rafael J. Wysocki" , "Dave Ertman" , "Leon Romanovsky" , "Paul Moore" , "Serge Hallyn" , "David Airlie" , "Simona Vetter" , "Alexander Viro" , "Jan Kara" , "Igor Korotin" , "Viresh Kumar" , "Nishanth Menon" , "Stephen Boyd" , "Bjorn Helgaas" , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= , "Pavel Tikhomirov" , "Michal Wilczynski" , "Ira Weiny" , "Philipp Stanner" , , , , , , , , , , , , , "Asahi Lina" X-Mailer: aerc 0.22.0 References: <20260824-unique-ref-v20-0-490735672187@kernel.org> <20260824-unique-ref-v20-4-490735672187@kernel.org> In-Reply-To: X-ClientProxiedBy: LO4P123CA0491.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:1ab::10) To LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:4ab::19) Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LOAP265MB8560:EE_|LO0P265MB2635:EE_ X-MS-Office365-Filtering-Correlation-Id: c199a891-13f7-4282-70cc-08df0c170d38 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|10070799003|366016|23010399003|1800799024|6133799003|10067099003|56012099006|4143699003|18002099003|22082099003; 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:LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(10070799003)(366016)(23010399003)(1800799024)(6133799003)(10067099003)(56012099006)(4143699003)(18002099003)(22082099003);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?OFlaNEZsc2cxUml4ZC8zOThBVnEzUElqNzFSZTkwR3FPL0NiSm1wSHJENEh0?= =?utf-8?B?NzgwNGhyd2c4N1VCS2hvU0l2cjRwVlhPSFY3b21iUjV2dUlaRURpdGg4SDJx?= =?utf-8?B?cTBOYlIzRmlRMUFLNkFlbmFuUldxUHhMVUVXeUlXUjdVUUcyR1AxNk5nNGNX?= =?utf-8?B?aXc5akdrV3lFczQyenNjVHdwZm16NzFKWE8rUFF4VVpjdVNyekJaeDlSOGFX?= =?utf-8?B?bDNMNkhpRTdwbTdWR0plVDlPZ3hpV2F6S3ZkOHRsZmdpMDdXTkRhS2RoWS8y?= =?utf-8?B?WG50bDlzVkNaSGdCSTJGVHYzZEVYR0R3QVZmQ04rTTEzVGlZSisxQ2hOeVIy?= =?utf-8?B?R3lCQlFwdVpKbFN3b244RW81ZEhodUl0QStBVWRWdHJNbWlmL2Z6Y291RDhT?= =?utf-8?B?SVFqdFg0R0tmUnZGeW9QNDJ4QVhuN1F0bFVYVWZUQ0FSRG5rNXZJTG9ndmhs?= =?utf-8?B?d2pLK09MaXFsRnRPcnRMSWZQUWppN0w3RFI4L2hzTGp6dDRJeFFxNkxYbktq?= =?utf-8?B?bTVWZ3hmQTZDSVpoV0M4b1lDY3R4enl1VDVZNlgwZHNyL1g0OXprUUVPYXNR?= =?utf-8?B?RWVuNDJVZHk0THdMOXBKTEFvT3AvL1ZjTWtha2loUDNoY29rckx5a3RSVUVD?= =?utf-8?B?TU5HNll5b0o4a04xV2c1ak9TQjUxVGxyN3Fvd1FuZ3FHOEFUdTJQekFNSE8x?= =?utf-8?B?RFlTanBBZTljdThGNUhiM0htSHllNlpORm1jUVZLZjJpanhUaFd2QjRaa3J5?= =?utf-8?B?cndqdWRVSFMvQmxlb0UyNG5MLzlTLzdSeUNDQ0pWM0FWdVZCNy9ySjU2MHdV?= =?utf-8?B?dVV1cWVYUnFROWpSUys4dWZUcEV2SGdsZzJWcnA4dmFyOFlJeVhMYjJUZ3RI?= =?utf-8?B?TjZuekdaTkJoNkZuM0plMUhZTmFKYTBKRzBxQml6dkhrZm56YURHTittWlpu?= =?utf-8?B?VWVrUWhPODlLbkxWQnlCTm9ZTmxhRzN1eVc1ejAyVUc0ZDI4aFdUamo5d2NW?= =?utf-8?B?cjZ6TVc1a3RZUndoVXFveEdMNEsvWjlpSTJzTGR2SUZoeSt4bVA1Q1VPN2I4?= =?utf-8?B?bVl2cFVIU1FXOXNQL0RIUXBINlpZR3dsWldsNnAzdTF6N2NLeVV5S1QrdDV6?= =?utf-8?B?cVFNSXpRUXc5Y0MrTnNsd2k1QXdvMkkxOS8xZGNLaktHNWNrM2hmN0tScTZG?= =?utf-8?B?bGp0WlpMN3NyT1cvYW8xVlR5d0tleHJTZ0xjSmx0RlBsMjE5YTUwTTQ2eHht?= =?utf-8?B?NWhsQndUWUVZczJ2R2R5RFdtYWtFbG1JRU0vV25iL05WeHJINkZZVDZKRFRw?= =?utf-8?B?cWUvRDY5RCtOcERTNHRLdWJVb0xvb0R5TEphc2poSEM3UHM5Q1A1eXNycXdD?= =?utf-8?B?SmZ4bzdXTkh1VzFTV29NTlEvcjlNcUJjdEVqSGlhMnp3TGhCb2hiSU1HS3dR?= =?utf-8?B?VXFPK296RDVqVFRhMGNJKzFCckVQQ0w2a1k3Z1F0dUhnUkRrRnZxMXNkQk5m?= =?utf-8?B?ZHp2ZyttaThsZjIvRHJtVDZ2VHRRdjFWNWFXK3NkY09kTENicFZxN1Jkc1hL?= =?utf-8?B?TlVMRDY5aU9SQWVNMThuNGJLYUZ5TjJRSHJrUjErQ3JSbjAwbVdQNjFtQ3pS?= =?utf-8?B?UzRTc0VVbUJRZHhPSnhJZkdBUWpCVlVXMkZ1MnFhcm9mQjVRQ0NhbGpET3VN?= =?utf-8?B?NGhrZU5YSWpISitzUXl1U2xXOWFLdVoyc1RVdzZCNzRXdmhIVHRWU1NYTU93?= =?utf-8?B?cTdaYksyRzhmMDk4UTFWSmpLRTRHcWlIU0d0TzlnTzExckpodVJ5bnA4enhh?= =?utf-8?B?OUwwK3pmUGd1SjJFU28xN3RWc3FFaXBoQVRRcGNCN0V1aGZNck8zTHFVakF3?= =?utf-8?B?c250OEpOUEhhVmRRR2xKVlIvK0RWWVdtdC8yNE1oeVZranE2RmNiOG0vRndS?= =?utf-8?B?RkdXdU9Zb1I0L1FQcUtxNk15NlV2bjVzU2YvUmd5aXlvTms1VmpxQ01hQmdS?= =?utf-8?B?KzZxM0VvTXVZRFkvSjZHWVdVK05mQ21naldmUlI5d0QvN2Fzb2FOYnE1Rkhy?= =?utf-8?B?Z3NOMVNoYmZ3MUNFMk5QaTNCVnZhcG96TlFlQUdHK2lOTERWZTRZbXJIOWEw?= =?utf-8?B?MG4rTWdWeTRJRWEzTDUzZmdkN3BHaVF0WTQyTWRBNlFndEVhQnljeWd2cTVq?= =?utf-8?B?WktMQklOMGNKMENwWC9pMS8xU29HUEp0RWZLbS9yVWRQOThFM0NXa1VTanZU?= =?utf-8?B?VFFyMzM2cEw4MG1uaHRpd1hCM21ENTE0cGUxWDM4SHJhL3JwRFppSVViNzFM?= =?utf-8?B?V002d0x6aXNZTDdNOWpnc3ZjZTZvcEtURzV0OWphbWE2dGNVaklFZz09?= X-OriginatorOrg: garyguo.net X-MS-Exchange-CrossTenant-Network-Message-Id: c199a891-13f7-4282-70cc-08df0c170d38 X-MS-Exchange-CrossTenant-AuthSource: LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Sep 2026 13:02:05.6269 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: bbc898ad-b10f-4e10-8552-d9377b823d45 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: AkauLTZx4X5Dz4gvyJANoeWosPMdYVkCsolGiDnoKV15dWosTp0jrJx8X0MuQySK6grKcr5AhOiWH/U23Qp8JA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: LO0P265MB2635 On Tue Aug 25, 2026 at 2:20 PM BST, Alice Ryhl wrote: > On Mon, Aug 24, 2026 at 01:17:56PM +0200, Andreas Hindborg wrote: >> + // SAFETY: We just successfully allocated a page, so we now hav= e ownership of the newly >> + // allocated page. We transfer that ownership to the new `Owned= ` object. >> + // Since `Page` is transparent, we can cast the pointer directl= y. >> + Ok(unsafe { Owned::from_raw(page.cast()) }) > > This doesn't satisfy the safety requirements of Owned::from_raw() > because the page may be used with vm_insert_page(), which increments its > refcount and causes it to be shared the vma system, and this occurs > before Page::release() is called. I suppose the existing vm_insert_page() abstraction we have is already problematic, because it uses `&Page`? Maybe we want to change the API to use `ARef` so it already has to be shared? Conceptually it takes a reference count from a `&Page`, which isn't possible because `Page` is not `AlwaysRefCounted`, so it needs a `&ARef` to be able to do that op. Best, Gary