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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3435BC74A5B for ; Wed, 29 Mar 2023 20:34:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229661AbjC2Uea (ORCPT ); Wed, 29 Mar 2023 16:34:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229379AbjC2Ue2 (ORCPT ); Wed, 29 Mar 2023 16:34:28 -0400 Received: from GBR01-LO2-obe.outbound.protection.outlook.com (mail-lo2gbr01on2114.outbound.protection.outlook.com [40.107.10.114]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 520505FC4; Wed, 29 Mar 2023 13:34:25 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=ZSUqvIMT2OW1MnR0TuhYs9yW774B2K9snII9MeAYIjasgwWgNaVM46Rt4GzvINkthnrPQrFA3igN6a3dnhSUWMuPEdLnoR20AjfXt7wPupg4aV95v7LOQX54h4K7nCL6SgV5Erv/9lZIr5WXHlAoyDdWOQHUOOpKHHqN1LYdohyRAhcLsVDVScCgxSiogO44N5qeGEkD7DMdDN2xcMvbzAcN8WuZF2wkT3xFwsaB+GXamDmFjwVFED8qFCD5h7tOLUKtvXo/AnNGUk8m/XTLskTdvvTq+S1wdAHsfPbUkgzWN8z32egp7rfwR5LbybqaU924spMnZ6N4HITarWnR7Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; 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=wBjhxCBy9NzOtfjP6pUvHkdxuU16C/2eLKC2EcUiMPk=; b=CCnYrjGhWCVuRj7OsrkEAcT6MjynveoI46zNvXVvjfaCumKHPXpLDZZUIts6yGa6OlzKhsNJZ3t9rvF7Q/2Q8AdUsW1/ICX5TpI4zaQVFLxuZ15tKKM2j9UAFOzk1ZmM8eXVBqZBsICAAgMaCDGLGYFqoHLXgYmxdPNBuOtPDOUaMNrHM4lTzI3aG0nZ7XGxbl7hWCHSXOcBCPxFeULX9eHbbQTMhBFRNFH9jWVfD5RBEpmCKvs5U3kjCa0oPa+/D2cFXk4rVc5tryKfnKfadgjGHS+FNgyInC9NFO0LjvaXMWvrmqAv7jZfgA8fZbOLqCwavx28nMrsattWAITvrw== 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=wBjhxCBy9NzOtfjP6pUvHkdxuU16C/2eLKC2EcUiMPk=; b=oB20h/5ddS0pm2vSG6nnMB7zDZxg2zka8L8t1x1iUqaWDxL4/hEc3PZpq0EanHjLGH/ck/fVhIlK+EgjLJGjopmceLUONIRRoejLA4yTQIMIAVoXPuU5UGMLk9hOWVrPQpMF8AIQD4k5QhNYmwHtR7dAvFBBIQdfFTauCxhJoN0= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=garyguo.net; Received: from LO2P265MB5183.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:253::10) by LO6P265MB5984.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:2a5::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6222.33; Wed, 29 Mar 2023 20:34:23 +0000 Received: from LO2P265MB5183.GBRP265.PROD.OUTLOOK.COM ([fe80::2f2a:55d4:ea1d:dece]) by LO2P265MB5183.GBRP265.PROD.OUTLOOK.COM ([fe80::2f2a:55d4:ea1d:dece%4]) with mapi id 15.20.6222.035; Wed, 29 Mar 2023 20:34:23 +0000 Date: Wed, 29 Mar 2023 21:34:21 +0100 From: Gary Guo To: Asahi Lina Cc: Miguel Ojeda , Alex Gaynor , Wedson Almeida Filho , Boqun Feng , =?UTF-8?B?QmrDtnJu?= Roy Baron , Sven Van Asbroeck , Fox Chen , Martin Rodriguez Reboredo , Andreas Hindborg , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, asahi@lists.linux.dev Subject: Re: [PATCH v2 2/6] rust: error: Add Error::to_ptr() Message-ID: <20230329213421.7d132f78.gary@garyguo.net> In-Reply-To: <20230224-rust-error-v2-2-3900319812da@asahilina.net> References: <20230224-rust-error-v2-0-3900319812da@asahilina.net> <20230224-rust-error-v2-2-3900319812da@asahilina.net> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.33; x86_64-pc-linux-gnu) Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-ClientProxiedBy: LO4P123CA0421.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:18b::12) To LO2P265MB5183.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:253::10) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LO2P265MB5183:EE_|LO6P265MB5984:EE_ X-MS-Office365-Filtering-Correlation-Id: 22cc1ce1-7d90-486a-131b-08db3094fb59 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; 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:LO2P265MB5183.GBRP265.PROD.OUTLOOK.COM;PTR:;CAT:NONE;SFS:(13230028)(366004)(376002)(346002)(136003)(39830400003)(396003)(451199021)(6486002)(478600001)(6506007)(6512007)(54906003)(186003)(4326008)(5660300002)(41300700001)(2616005)(8936002)(7416002)(2906002)(1076003)(26005)(316002)(38100700002)(66946007)(66556008)(36756003)(8676002)(66476007)(6916009)(86362001);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?1heTLHwggZmMnlQcoOvMSszX6JN8MvzL6UEIl+1aJGLrouTivgu1y7y+Bm6S?= =?us-ascii?Q?B3q8Yo5jSgc0MfRIf2iri/+n5tA1jKZtX62L3s28iaFOUwYALFzOF1cdMHbW?= =?us-ascii?Q?c/vFa9uno6iZyjny96TK6BUS5GFBMpeoBfbvWKAXgYptsearMasN2yUb3ogJ?= =?us-ascii?Q?oN9C4v7cG8YJEbT7AfLMDR+GGQ+52gbpiQFXNfMTwDHHxAyUUoKFXpUnt53N?= =?us-ascii?Q?wL3hutcz9ioTdAiUop7D+RddCzzIfia9+FJtVlo3BeOZpSRxvP50HbkCOU7w?= =?us-ascii?Q?hAqIbbdHo2LIZIjOP6Enkp7580RVP71yownYluMJ7zkZQWiCuNiC874cKe09?= =?us-ascii?Q?rsfjR8TpgLZV5JoBosQumvA20eeAyFAVr6C/Yzz9fWZQ85Cc+UCV796AoV2o?= =?us-ascii?Q?ky73EpY+AyzlhGqm9V0+/LABWK730TXFwiM/zDNrLCOOJ+CXnkwEyxhYXXxZ?= =?us-ascii?Q?f6VhJvmv9HA7TyeWMCLr+M1WP+Ewuq4p0+M8rshvQtmj8e603qKg/V3U1Hv5?= =?us-ascii?Q?vbI+WQaYWvI/4M9JG7ahJs8+HUtCIAo9DRaVOjJrM2Yb2ztnrSVKBZ6kkFrP?= =?us-ascii?Q?Joi/SeKnuv36hpOv4BDjBKjus6f3k1iwzXO6FiTQZ1n5I/ailYCymWkkrpaw?= =?us-ascii?Q?PYpr12I5Aq0tiJqext0t+rKqfs6sgA3VhxKJKAUNErO23Quc2YCsKQogdKr4?= =?us-ascii?Q?Vd74JsWqLlZz84Cn0QJda+bcCPihec2glkcdf4crmeqU95phLPJVYJC8c3Qr?= =?us-ascii?Q?K2BQIRqLrGiWDEGXGBAuIL3Gjw7O8IAWdGPF+EXhhY1A20YrRkud66EY5oi1?= =?us-ascii?Q?SDQM2seATiKwA0Bw6qdKLR5lhy4JCrGrFDMRJwacl+Sj6E67alquQEopTjJR?= =?us-ascii?Q?Y9stLdc6DoFVl+6BkQeQwIumdCYDsY2qqqVtL8ESNUR9P14GTQgwktXtpe4v?= =?us-ascii?Q?DUvw2DzZD342DRIWEhJEClYwdwU6ALpdhMbv6lsKsOCkQpBswIPoBEImKUDX?= =?us-ascii?Q?DT4BvwFW44UPNCYee/aVKcUQfZqLBWHKuh/FlYnX1d9qcxzxkTxGcWy+CfYl?= =?us-ascii?Q?XYfIQPLDSavIfzrf9qXB8nMUeIUHifROs2iNtBf9wJMu+EQPDF1G+zkIWySb?= =?us-ascii?Q?vqbCBHiHup8WfsUUx/5hIOrpfGVudGKfekI6QhygExKphF55lPnCLq4ffKED?= =?us-ascii?Q?QxtE58z4+E7ZdFx1/oqhWmtVuvQJfLLYWBelXbgTCi5XczDmAn/ro0tpRjiW?= =?us-ascii?Q?4RxCuYCuoMJGSk1rzj5rAxdKzcUZQ7NpHWYNTx1BXaRA8CsPRImjRfGEBCMt?= =?us-ascii?Q?+1d5ZSSP8nR7cswd/UvQkq3Ar9sGap4G2z9Mlo75RrI3gihclbx000q3eiMu?= =?us-ascii?Q?9qvPkDxIbF1FEeCM+nbIxBFJbKrFV/tRsUVr27VrGe7UDbpwBbWtQLwVsAZG?= =?us-ascii?Q?DGwbiu9+wJloVjrOTKn15gUq+qOCIZEfnts2GeoVDgfZRpUXujY6xPuuwYos?= =?us-ascii?Q?TPJz4J7KK5oiL7ayMjVXxe33MXTDf7H6nogDkLe2TVSfn4nEL8BNQF3c/jBm?= =?us-ascii?Q?5ywWUsKnK5lWlp++iNIbP05Xl9mebRz7ONbC7dkI?= X-OriginatorOrg: garyguo.net X-MS-Exchange-CrossTenant-Network-Message-Id: 22cc1ce1-7d90-486a-131b-08db3094fb59 X-MS-Exchange-CrossTenant-AuthSource: LO2P265MB5183.GBRP265.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Mar 2023 20:34:23.4550 (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: eQseP2is8zidKQMNllE5Ibrc5Wjt4JixI4GxDoLQLDFiZcDe6/jA5PK6JquQCJ/BTipPk5UUBSuqottc1TXZ/w== X-MS-Exchange-Transport-CrossTenantHeadersStamped: LO6P265MB5984 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 29 Mar 2023 21:04:34 +0900 Asahi Lina wrote: > This is the Rust equivalent to ERR_PTR(), for use in C callbacks. > Marked as #[allow(dead_code)] for now, since it does not have any > consumers yet. > > Signed-off-by: Asahi Lina > --- > rust/helpers.c | 7 +++++++ > rust/kernel/error.rs | 7 +++++++ > 2 files changed, 14 insertions(+) > > diff --git a/rust/helpers.c b/rust/helpers.c > index 09a4d93f9d62..89f4cd1e0df3 100644 > --- a/rust/helpers.c > +++ b/rust/helpers.c > @@ -20,6 +20,7 @@ > > #include > #include > +#include > #include > > __noreturn void rust_helper_BUG(void) > @@ -46,6 +47,12 @@ bool rust_helper_refcount_dec_and_test(refcount_t *r) > } > EXPORT_SYMBOL_GPL(rust_helper_refcount_dec_and_test); > > +__force void *rust_helper_ERR_PTR(long err) > +{ > + return ERR_PTR(err); > +} > +EXPORT_SYMBOL_GPL(rust_helper_ERR_PTR); > + > /* > * We use `bindgen`'s `--size_t-is-usize` option to bind the C `size_t` type > * as the Rust `usize` type, so we can use it in contexts where Rust > diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs > index 35894fa35efe..e97e652a1aec 100644 > --- a/rust/kernel/error.rs > +++ b/rust/kernel/error.rs > @@ -76,6 +76,13 @@ impl Error { > pub fn to_errno(self) -> core::ffi::c_int { > self.0 > } > + > + /// Returns the error encoded as a pointer. > + #[allow(dead_code)] > + pub(crate) fn to_ptr(self) -> *mut T { > + // SAFETY: Valid as long as self.0 is a valid error This should be something like "SAFETY: self.0 is a valid error due to its invariant."? Best, Gary > + unsafe { bindings::ERR_PTR(self.0.into()) as *mut _ } > + } > } > > impl From for Error { >