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charset=UTF-8 Date: Thu, 02 Jul 2026 15:48:09 +0900 Message-Id: Cc: , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v5 16/19] drm: fix race between partial drm_dev_register() failure and ioctl From: "Alexandre Courbot" To: "Danilo Krummrich" References: <20260628145406.2107056-1-dakr@kernel.org> <20260628145406.2107056-17-dakr@kernel.org> In-Reply-To: <20260628145406.2107056-17-dakr@kernel.org> X-ClientProxiedBy: TY4PR01CA0006.jpnprd01.prod.outlook.com (2603:1096:405:26e::13) To CH2PR12MB3990.namprd12.prod.outlook.com (2603:10b6:610:28::18) Precedence: bulk X-Mailing-List: nova-gpu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH2PR12MB3990:EE_|PH7PR12MB8039:EE_ X-MS-Office365-Filtering-Correlation-Id: 3e26de3e-b9d8-42a8-26ad-08ded805e31d X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|10070799003|7416014|376014|23010399003|18002099003|22082099003|11063799006|56012099006|4143699003; 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Since the > unplugged flag was never set, the ioctl proceeds while the error path > tears down device resources. > > Fix this by introducing drm_dev_synchronize_unplug(), which sets the > unplugged flag and waits for the SRCU barrier, ensuring all in-flight > drm_dev_enter() critical sections complete before cleanup proceeds; call > it on the error path of drm_dev_register(). > > Fixes: bee330f3d672 ("drm: Use srcu to protect drm_device.unplugged") > Cc: stable@vger.kernel.org > Reported-by: sashiko-bot@kernel.org > Closes: https://lore.kernel.org/all/20260620190648.2E9F61F000E9@smtp.kern= el.org/ > Signed-off-by: Danilo Krummrich Reviewed-by: Alexandre Courbot