From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=pass header.oldest-pass=0 smtp.remote-ip=52.101.196.103 ARC-Seal: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=pass; t=1792423854; b=IGsAOfl7L3VWSHa3LcX4tssymp7Ct7lZIn7Auzkkmt1O9fYPAw2osqfQDjJwKmGf4xxa bBHntNgK5hfo18UdXFmEm2kd7jdsDYcn1ZhWR9lHVj7bTeG77/AvyCQPhtkSlWlohUKug pUOAarHWg7IWeHxFW1aiwr8rLZgX4M/+MJOH0nZGjkC6GzikQB0T1QvriBY1kqjwC6m4s ZNUeWHnssJm5mQwOfqqatRhJWraL+pWfK3iQrEkT1qnV2lnwhTvzHb4asSbRFHWNQrDRD 4NjSaVOq3DqdNVIH08hlM4i5C6vyDb873dSifVUpiOx4h4G+shPvivM0r2E80c4RGow== ARC-Message-Signature: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792423854; h=DMARC-Filter:DKIM-Signature:Received:Received: Content-Transfer-Encoding:Content-Type:Date:Message-Id:Cc:Subject: From:To:X-Mailer:References:In-Reply-To:X-ClientProxiedBy: MIME-Version:X-MS-PublicTrafficType:X-MS-TrafficTypeDiagnostic: X-MS-Office365-Filtering-Correlation-Id:X-MS-Exchange-SenderADCheck: X-MS-Exchange-AntiSpam-Relay:X-Microsoft-Antispam: X-Microsoft-Antispam-Message-Info:X-Forefront-Antispam-Report: X-MS-Exchange-AntiSpam-MessageData-ChunkCount: X-MS-Exchange-AntiSpam-MessageData-0:X-OriginatorOrg: X-MS-Exchange-CrossTenant-Network-Message-Id: X-MS-Exchange-CrossTenant-AuthSource:X-MS-Exchange-CrossTenant-AuthAs: X-MS-Exchange-CrossTenant-OriginalArrivalTime: X-MS-Exchange-CrossTenant-FromEntityHeader: X-MS-Exchange-CrossTenant-Id:X-MS-Exchange-CrossTenant-MailboxType: X-MS-Exchange-CrossTenant-UserPrincipalName: X-MS-Exchange-Transport-CrossTenantHeadersStamped; bh=EVPt1VNtS6W72JEnP1b4RjqqniLorVUyva/9LYhzXl0=; b=zKftek2e0j2T8QOLswGw18M0pF5kX/E+w6lxKm3DHwccBTH+59GNpljZha+A8nENFWLv figQ60UbhCvXs0U7QPbZbNbFo05LPtxWW1AxWx7nMIZfgcmYxuk1QvAmnLK+NANSpwQgj SWPlru0SzwIskS47E2+wX68PFzBSldSLbIjEyAldO/OPKhqE7hC9pdDH3IWd7AbZuAAMi b1SdizYAx6avRiaaVHwRhOo6KQuhtfFL1bVppgxNqGDggS5qJHfmJPptIGF7+cIOHopar qQSlTNReBZaAJKnDPfm0UElImrDK4E7enhVx+Z57T+plAsZOVIJVe//ZVL2x3OvadCA== ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass header.from=garyguo.net; spf=pass smtp.mailfrom=garyguo.net; dkim=pass header.d=garyguo.net header.i=@garyguo.net header.a=rsa-sha256 header.s=selector1 header.b=LEWBqcSt; arc=pass header.oldest-pass=0 smtp.remote-ip=52.101.196.103 Received: from LO3P265CU004.outbound.protection.outlook.com (mail-uksouthazon11020103.outbound.protection.outlook.com [52.101.196.103]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (secp384r1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5129060AA0FB; Mon, 19 Oct 2026 15:30:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 5129060AA0FB 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, unprotected) header.d=garyguo.net header.i=@garyguo.net header.a=rsa-sha256 header.s=selector1 header.b=LEWBqcSt ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=guaaP90aRnh5eKnuunV5t7KrvvsVWvr5G9V9rzXhlqddLTl5Fn96Ts+B752MR5+PIlt6WCzxliyn03BDQzUcd8m9+m1dqnwgoG7pzl/1/4yl7Y+ZwjGShiWmxshXWuKyzmaI1cUv4pExWMKxPS/tUnzDq517vJ6uacwpX/a4adj5R7665sJDhm6K6mbte4/hFwlMiWJodZmsUBNl7q77QnDQyijsns7kpEIFYiPecgPPcn6uv0wOnxWC5HcKUPCCBkAA0+msuZOUhulF8g9sI32gEY0DFVV+WynIiuq1S+QCT1wE90NHbusPITkeN2YtPyH++WUhwzZKCMFAzJsPLA== 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=EVPt1VNtS6W72JEnP1b4RjqqniLorVUyva/9LYhzXl0=; b=xGxl5dWHfw5UVR8uW35rbq/h6l1/3K6lH3H+TI0XlMF78bnwU/t/6dyemzaigoYlGdNcdyTzTrTJhICZhaUAvr92LQgmXn3dBx7AktHyezOFLhm0wf9iDhE9RV2Kfp+1c8CJrsqfcX2FTHHFS3uShpkl3GJk6P1a1bJIFMSwu5R9n5vSeYO/Y3cS4kbAkcq50mPfttBVHQiyNmg7ZYu+IosoJd5DAO1PBKv/5tdyXjDfACcUj0dt8xZCJ+CeFURVyZ9kTSzyh6LrCz9xPz/O4FT7GtVi/k6YaLQxSbQtaattY8eBWIFburXf8KKSuzQSqPzzaJLYAUDwsPSvmqHgnQ== 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=EVPt1VNtS6W72JEnP1b4RjqqniLorVUyva/9LYhzXl0=; b=LEWBqcStKCdN5N3dMnLkSO2RSixN1AARcqsLoe1jh+Nf3L/qY1+tXf8fYPHZPP+VhXMFfxtZfXv1U8uVdGu+LfQwBcQY0kGDzEfBJW1Ek1F5fIyompjgk9PhjMaOdesEsGBoyDqDmwz2oaZp4TdSfc2qqDiGU9b5pS7eKAI5x9k= Authentication-Results: mx.microsoft.com 1; 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 LO4P265MB6279.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:273::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.522.19; Mon, 19 Oct 2026 15:30:50 +0000 Received: from LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM ([fe80::f60b:1537:68d7:4fc1]) by LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM ([fe80::f60b:1537:68d7:4fc1%6]) with mapi id 15.21.0522.017; Mon, 19 Oct 2026 15:30:50 +0000 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Mon, 19 Oct 2026 16:30:50 +0100 Message-Id: Cc: , Subject: Re: [PATCH v3] rust: sync: Accept errors for Lock payload data From: "Gary Guo" To: "Philipp Stanner" , "Peter Zijlstra" , "Ingo Molnar" , "Will Deacon" , "Boqun Feng" , "Waiman Long" , "Gary Guo" , "Alice Ryhl" , "Lyude Paul" , "Daniel Almeida" , =?utf-8?q?Onur_=C3=96zkan?= , "Miguel Ojeda" , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , "Benno Lossin" , "Andreas Hindborg" , "Trevor Gross" , "Danilo Krummrich" , "Tamir Duberstein" , "Alexandre Courbot" X-Mailer: aerc 0.22.0 References: <20261016120926.1213105-2-phasta@kernel.org> In-Reply-To: <20261016120926.1213105-2-phasta@kernel.org> X-ClientProxiedBy: LO4P123CA0617.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:314::18) To LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:4ab::19) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LOAP265MB8560:EE_|LO4P265MB6279:EE_ X-MS-Office365-Filtering-Correlation-Id: 86282535-bc43-4d3c-2508-08df2df5f4c1 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|23010399003|1800799024|376014|7416014|10070799003|18002099003|22082099003|921020|10067099003|261009223027099003|56012099006; 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)(366016)(23010399003)(1800799024)(376014)(7416014)(10070799003)(18002099003)(22082099003)(921020)(10067099003)(261009223027099003)(56012099006);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?VGFRTmJtK1NpNDhESFFNRGlyUGJSRG5lV2J1Z0tjK1dacU1rV1NjaTFRVnZR?= =?utf-8?B?SkRnQXJWeTR6SnBZbURkT3g5eEhKbTZVSEJOYkh1NGFoUkpDMmxCY1NCa1pn?= =?utf-8?B?eXRJVy9EblN1RFRvdG5LVDJtcXRGSW84cEJGaEZHT2FrMHVocC96aFhpKzFG?= =?utf-8?B?bzNUWFZuZ3J6OHVEd3lDWnduMlNsbVZyeTdKaTJuYUxmWHY4dEZCVzVpa1hF?= =?utf-8?B?cWk5RmdtUVdqYmNueU9vMHQ2QTFPOVMzOGQ2dEdlQkp6bmFxcndZYVFFRCtF?= =?utf-8?B?aExHbyt6OHhlT2FNUkpqdzVuRnV0eC8xazQ1QUFLRUdONHA1cGdPc0hnay9U?= =?utf-8?B?N0JleTQyNnRwYkdVUlBsbFFOK1VTRUdpQmVFY05UN0I5WkZoTDlOK01sOVVu?= =?utf-8?B?YmFZOHFqMzFBbG8zOVFqWCtzRFk1N005bmNtTDNBQXVDQUVmTTV6TWZRVnB3?= =?utf-8?B?Q29SbFZWcTJ6TzZnNFFVVlZXWjRVdW9YKzlidDVDME5pYW13bUFKSGVDYVls?= =?utf-8?B?Y0l1eHplRzlaZktkMDJpU0xpY3Z0ZWNUQzZPUFR0WWpCU1BlZnpicStJc0Fh?= =?utf-8?B?MnJjQVJiZy9HcXBmMUhJVWtjY3ZJdlFEMFhUS2R3YlhGVVQzbUNNVzdPODho?= =?utf-8?B?SklwZ2FLYkFGUjRmQnE1UDVoWDJROUFwNzJwTjBEUHhqY0VnTnlpN0ZEdFI1?= =?utf-8?B?NzVBM0t6SEFQUGJldzZWVnlvbm1hYTVkK09uZTVsMVltNU4rVGF6bUxrNVZ6?= =?utf-8?B?WEMxWFYwams3ckdFVFhLdUdQd0lBZEw4YWN2dE4weDRldnplVUNETXh2TnNq?= =?utf-8?B?YjRac3plQ0d4eW1MTGpNWUJGajl5a1BZeHRsblYvQUhXd3RJenFpUjFqMnJJ?= =?utf-8?B?QjBiOWx4ZHE4NzhXRkNKMXFVeUptYlZlSjBnaWtzT1Jjd0Q5VHBjMnhyN3Nk?= =?utf-8?B?alVXUHhPbmhGZENyMlBBTG9oc3JFbmQ2ZGFMRWg5WHErVm5pL1FQMDRBekdS?= =?utf-8?B?d3VPdGk1Q1AybjZNTnUvSFE3TCtVWnJOOVhGRUNTbWJ4T1FLckZiK0trVDFp?= =?utf-8?B?TzU0SGRLZjV1aXErc1lnaTdpaE9rT1BHVGhCOUl0TS9wSFVYYTFRWHoxYjcx?= =?utf-8?B?U0lUS0Jid3U5NHpCSDMyaTQzd2tQbVQ3c1lXS2xKOHRvLzJhczYyaGdGZks1?= =?utf-8?B?Mk9Mc0tVb28yUWVxZWRINEppcXkzS2lkei8wYzNVRmJBNkM2bkpQSlJYa1lq?= =?utf-8?B?UEZDUHg3amZDMDJRSlRLV0lCbjhYWStFaUdObVY3SkNzOVVVNXpZWEt0TFJR?= =?utf-8?B?ZzVaemt0eUdKcE9XMnpLRDNpRzlkWXo4RUMySW5UbURtZ3VWZUJ0WWptNytY?= =?utf-8?B?NFRKQkhCSGhNRVBtcWpjbkp5T2o1b3I2ZUZIMjUyUzIzM05HVVhJdjVsVkYz?= =?utf-8?B?OW04eVRtS0UrSkFQZUMzVjVTQW53b045SVJzbHQxOUt5aUEyRUVyZ3Qzck5p?= =?utf-8?B?ZExkcEMyd1ZPM3o4emNHWVV0ek5ybGRCaG5hdHJtK1Q2V1dEM0Yzb3JQc1ky?= =?utf-8?B?RElTRlY0dE4yMVRSMnFEeGpidGdoOXRRdnZqTk1vSGo3anczVzFOMjRSbFdE?= =?utf-8?B?c1dPNFRKVmJHakduTmJEcVZ2Z09LVlc5N20wVDNlVFppOFhYckNUMkUwRE1J?= =?utf-8?B?dGl6NEhBVnpUNGVCbWJTMHlWYktWdklGSjdDSDhjV29QYXJvVzlnbzhicDB1?= =?utf-8?B?eVhhN2Y0VFpsQ1VmTTVUL0wrWXQwdVZRVEVkMGRWb3VnLy93TXVrSFF2ZHRW?= =?utf-8?B?Z2wxSXljUUxFZVV5RUpDdlFsZkpOZWlmd0RFclVJYkljL1RJeDZNMUJweC9C?= =?utf-8?B?b3V1RS9weE51ZHlOZ3l4NHpuMStCdDkzSURLMWxyTnNVQUpUTnZHTzV6YjA0?= =?utf-8?B?amcxcU1ldVZtNjFTVWU2eTB5M096S3BPK2VXdWM1WDJodSs5S0V0SmkzRmNn?= =?utf-8?B?eWtsaXo5QUkwanM2VEQrQjF2SDBmditmNTlOVnVBZW9TWkRUdkhpb2FMUUpL?= =?utf-8?B?ekI2VFViTnh6OUh4aENwdHZCdWtCd0poK3p1Y0M2aWJ0bVFLOHFBNjZacGNB?= =?utf-8?B?dWttb1pvMGJsMWVzd1FxSzJUOGowSW9lR0Rxbk5halBCK2RZdnJlaGtLTzF2?= =?utf-8?B?Z0dwVmpkUXNENFp2YXdiMjN1OXJ6MG5xTElWZnpJVlB1bE1ZSUdkeWUxQzcr?= =?utf-8?B?R2NxeG5VYnU5cUpDa2xKekdZOXZsL1dWWm5QWlg5MVBVOSszM09nWTdmUFZE?= =?utf-8?B?TkV4WGhaczhKUFBvcWpwOGkxM1JlSUNMZFAxamFoNGRnejhtdSs4QT09?= X-OriginatorOrg: garyguo.net X-MS-Exchange-CrossTenant-Network-Message-Id: 86282535-bc43-4d3c-2508-08df2df5f4c1 X-MS-Exchange-CrossTenant-AuthSource: LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Oct 2026 15:30:50.8747 (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: ASjYt4wdzZuZ3X9FOxvaiamxOeMRk0qcOeEYS9SlI4e9y0cJBj3xsx3+srfdhAUoF9DLE/2kn5xJOvmMNl6lzA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: LO4P265MB6279 On Fri Oct 16, 2026 at 1:09 PM BST, Philipp Stanner wrote: > The `Lock` baseclass currently does not allow for fallible user-data. > This can cause conflicts when used with other primitives, for example > when a lock shall be pin-initialized with payload data that is fallible. > > Add support for the lock base class so that it works with > try_pin_init!(). Adjust spinlock and mutex accordingly. > > Signed-off-by: Philipp Stanner > --- > Changes in v3: > - Vertical formatting for imports > > Changes in v2: > - Don't import prelude in doctests. (Gary) > - Keep using pin_init! over try_pin_init! in Lock::new(). (Gary) > --- > rust/kernel/sync/lock.rs | 23 +++++++++++++++++------ > rust/kernel/sync/lock/mutex.rs | 6 +++--- > rust/kernel/sync/lock/spinlock.rs | 17 +++++++---------- > 3 files changed, 27 insertions(+), 19 deletions(-) > > diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs > index 10b6b5e9b024..5bff5228ac16 100644 > --- a/rust/kernel/sync/lock.rs > +++ b/rust/kernel/sync/lock.rs > @@ -7,11 +7,17 @@ > =20 > use super::LockClassKey; > use crate::{ > - str::{CStr, CStrExt as _}, > + str::CStr, > types::{NotThreadSafe, Opaque, ScopeGuard}, > }; > use core::{cell::UnsafeCell, marker::PhantomPinned, pin::Pin}; > -use pin_init::{pin_data, pin_init, PinInit, Wrapper}; > +use pin_init::{ > + pin_data, > + PinInit, > + Wrapper, // > +}; > + > +use kernel::prelude::*; This should be part of the `crate::` import. > =20 > pub mod mutex; > pub mod spinlock; > @@ -126,13 +132,18 @@ unsafe impl Send for = Lock {} > // data it protects is `Send`. > unsafe impl Sync for Lock {} > =20 > +use core::convert::Infallible; Should be part of import above. > + > impl Lock { > /// Constructs a new lock initialiser. > - pub fn new( > - t: impl PinInit, > + pub fn new( > + t: impl PinInit, > name: &'static CStr, > key: Pin<&'static LockClassKey>, > - ) -> impl PinInit { > + ) -> impl PinInit > + where > + E: From, > + { > pin_init!(Self { > data <- UnsafeCell::pin_init(t), > _pin: PhantomPinned, > @@ -141,7 +152,7 @@ pub fn new( > state <- Opaque::ffi_init(|slot| unsafe { > B::init(slot, name.as_char_ptr(), key.as_ptr()) > }), > - }) > + }? E) > } > } > =20 > diff --git a/rust/kernel/sync/lock/mutex.rs b/rust/kernel/sync/lock/mutex= .rs > index cda0203efefb..38d8fb9dad5d 100644 > --- a/rust/kernel/sync/lock/mutex.rs > +++ b/rust/kernel/sync/lock/mutex.rs > @@ -49,8 +49,8 @@ macro_rules! new_mutex { > /// } > /// > /// impl Example { > -/// fn new() -> impl PinInit { > -/// pin_init!(Self { > +/// fn new() -> impl PinInit { > +/// try_pin_init!(Self { The example don't need to be changed? The existing API would still work wit= h `pin_init!` with just `E` inferred to be `Infallible`. Best, Gary > /// c: 10, > /// d <- new_mutex!(Inner { a: 20, b: 30 }), > /// }) > @@ -58,7 +58,7 @@ macro_rules! new_mutex { > /// } > /// > /// // Allocate a boxed `Example`. > -/// let e =3D KBox::pin_init(Example::new(), GFP_KERNEL)?; > +/// let e =3D KBox::try_pin_init(Example::new(), GFP_KERNEL)?; > /// assert_eq!(e.c, 10); > /// assert_eq!(e.d.lock().a, 20); > /// assert_eq!(e.d.lock().b, 30); =20