From nobody Fri Dec 19 15:34:32 2025 Received: from CO1PR03CU002.outbound.protection.outlook.com (mail-westus2azon11010007.outbound.protection.outlook.com [52.101.46.7]) (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 607DD19D071; Mon, 13 Oct 2025 00:05:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.46.7 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760313961; cv=fail; b=jNqPsJwZ/Db1P6enGsvHo7vgN/IFxMzSOGL8lwDf4j/Vb8z7jASt90bnO8DS7v6vOHspwgZAdJsnpP+2am7TiXYx7iUtoQ+rhl2sfwky+gH9Q4dYja/V7SeUOcLiL5PGPW3eyRpT8ypGPtYzwGvdKGF0WayIooocEIvjzMcTRO8= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760313961; c=relaxed/simple; bh=hf9URtIB6b8I4ZAf2QKi6STYGKSa1yW/vwGtW/a3fys=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Uqdb5BdjewquhZ84Hoq445+HpYKzlZs8i05V0cJ4AAI3HONAIf7vKDaGC1cjo9lulS/ccyX2LlnDE9EtCCcYGFsV44/hJn/2fuD88CBeY57xjZb1KRELstGipYiz38v+ggm+0rFUytX3QiHEJg+Cb6hJP9iVhLtZbingn2T1zdE= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=JLKOqKox; arc=fail smtp.client-ip=52.101.46.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="JLKOqKox" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=qFg1TXGgLHUflvBajhJvWDP8KuQDakfiZvUPtM1iz/ytdg72p1ntggDbFv5yXOTR4DFZbF/oS90mm0gSXUTXAIkltpA9bnwysgtM2V77MhkWE3klUzryyEzMjmJASgJkSieMPASYp8ACe6TE3W2Q2eOsyuDFP95wkF0oP+JyusH17ZyDMvbBwcKJHiLGqa3n0BIXy9/Z7ObUKqiqnd6uZjJDn84+tPLZ+dOWgWA6jS7R3bVlW5eYrDA3LnPtMhyx+H2jNrvb8KfVM6eO7tfBy6jLjIBEcXM7iPuaKfVXbzXe1FznWiI5KWbWOSarOpJJgOC75sKst3BRb/KIpQwj7w== 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=3v0/G/vWFpwNFlvBx1Xplw6jWYY18YMwHMSdAL9y5WM=; b=ybhrwsixJYt+ABRHef6WWW07KMX4G6MFyoj9zEgLc403uHN9vfuRzgYYcTeSZWqGVYDaRQ4n8q5vlw3wyGxzZuW/9+LzUAfXCTQXSbQYoJ7+UjHUVtXUdlra3XqmNkmRQK1oR7yNXl7h6VFSjzu5v1pd/+wYXFVcwDKK3uknWSfOfG+fIYSZ+v/3g3Ckdf8eo4DzZp857nfsqNtZh8Rc22niqhc2WJHhatGzcnt4OLv+7E7pz7qXtgx9KEUl75Pg1fSJ4391cfX9Zj9vncKRij1X+SmMh8HrGPamqB3fXiCgfR45mrkLPZ7+cXuvvUcf/Ls1pS4tk0OzB4D+qIjtTA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 216.228.117.160) smtp.rcpttodomain=8bytes.org smtp.mailfrom=nvidia.com; dmarc=pass (p=reject sp=reject pct=100) action=none header.from=nvidia.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=3v0/G/vWFpwNFlvBx1Xplw6jWYY18YMwHMSdAL9y5WM=; b=JLKOqKox2HWEmzbQjA4wmvZE3lp55xVLwOjM+euGWYNcopFA/0OeOUyqBh+SCMDoASf2fXuWhL1ZrRPbEg4ipE2rgTw9RrmMDPmcJ3Q5OjsFfncuHTKm1JtqcryR8iKO4YVVBAuyrqd20nGPWJhSYkPzpfPJnF+5xnrlWY5Fkn2M6R2AdxW4x2O7YIQuAyyZubsC2irNrWZ7G9qUVDvNcCitc+5GH+ftDrmnnI4IKMUxoGCkk3y88gbasMkmzqnI/EyTHM+Y7bB7VN/kNUpgysnsPtDovPw3P4dwX10A76tVXvFjh+tXOBhz2t7uXa5T7ROzdgct2zOw6BryyTxafA== Received: from CY5PR17CA0014.namprd17.prod.outlook.com (2603:10b6:930:17::23) by IA1PR12MB6556.namprd12.prod.outlook.com (2603:10b6:208:3a0::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9203.12; Mon, 13 Oct 2025 00:05:55 +0000 Received: from CY4PEPF0000EE3C.namprd03.prod.outlook.com (2603:10b6:930:17:cafe::b7) by CY5PR17CA0014.outlook.office365.com (2603:10b6:930:17::23) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.9203.12 via Frontend Transport; Mon, 13 Oct 2025 00:05:55 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 216.228.117.160) smtp.mailfrom=nvidia.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=nvidia.com; Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates 216.228.117.160 as permitted sender) receiver=protection.outlook.com; client-ip=216.228.117.160; helo=mail.nvidia.com; pr=C Received: from mail.nvidia.com (216.228.117.160) by CY4PEPF0000EE3C.mail.protection.outlook.com (10.167.242.13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9228.7 via Frontend Transport; Mon, 13 Oct 2025 00:05:54 +0000 Received: from rnnvmail203.nvidia.com (10.129.68.9) by mail.nvidia.com (10.129.200.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.34; Sun, 12 Oct 2025 17:05:31 -0700 Received: from rnnvmail202.nvidia.com (10.129.68.7) by rnnvmail203.nvidia.com (10.129.68.9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.20; Sun, 12 Oct 2025 17:05:30 -0700 Received: from Asurada-Nvidia.nvidia.com (10.127.8.12) by mail.nvidia.com (10.129.68.7) with Microsoft SMTP Server id 15.2.2562.20 via Frontend Transport; Sun, 12 Oct 2025 17:05:28 -0700 From: Nicolin Chen To: , , CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v1 01/20] iommu: Lock group->mutex in iommu_deferred_attach() Date: Sun, 12 Oct 2025 17:04:58 -0700 Message-ID: X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-NV-OnPremToCloud: ExternallySecured X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CY4PEPF0000EE3C:EE_|IA1PR12MB6556:EE_ X-MS-Office365-Filtering-Correlation-Id: 3b9185ca-84aa-4a27-39a7-08de09ec478c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|7416014|376014|36860700013|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?vN3bJGBS3zeTYl+olBOIhGmJi9yfUmB5qaGsuPfMuTZcVgfm9sMXo4I9LaSK?= =?us-ascii?Q?sks4M6VCj1HGRubXgmBby7Oy4AfKFJQFTiOWV4YaOyivXdix80OUCRSDxxtH?= =?us-ascii?Q?TmuHxXuOwdHJ/4kcATM5F8fhqE1kEL0CsVW3XaQOw/MSQu/m0wO1k8FEvLqD?= =?us-ascii?Q?IvhzfpHb7I9zCExaV+tXWI4owUFCPcelqTHsMe48heLBGzuMj+fQh3COrABy?= =?us-ascii?Q?wARBbq2j6AA43s/VStsUm0VFhgSHj26/SQP/eyjI+2Y4BbZbK1WTxbFYviFK?= =?us-ascii?Q?W1kTXM6RBCGPGZvVevcXHTPpZdVOGRL6HVg9lEqWBdTuRMV//6b2HW6+Hzpe?= =?us-ascii?Q?MuCtfF0dO2b+0jlRcaZ9moNN5cI1ozl3ZRnAh+p/1n6BCcypVy2lzBcKtrDO?= =?us-ascii?Q?iyDSkQLaJStjJwDDW/2N1HwtS+Z8xodQRASMoqVSc8HlD6zvPF5JyeEjmnnc?= =?us-ascii?Q?aFOtHTjHf/jkDi9bErnB46sfFJfoWVNtLwSbY/u4mgezT2a+KyY3zx0kSPzo?= =?us-ascii?Q?uDPr19c+7jEET9bpMDizfEsFKVn8RAUw1sIHqrZETZNaxlqYVAUOus/aAJyX?= =?us-ascii?Q?GqN4jnJZoPNmi0Af17IbKq8XG5LP0/Fyv0WB8iqve/BfHjBSa5/1RgS55vvZ?= =?us-ascii?Q?+oHI7umtXQKLRhdlJDK0Go2nlXbnJAKn1T3ZoCP2AsQ0Wny1X+VQOIBszYMb?= =?us-ascii?Q?eJSRD+Q6vbnY/o+b2T/3MDF+4Rn5HRme5WUAK5ncYfqMKLa7L+AVdqShgkI7?= =?us-ascii?Q?LgZX5avVFT3Sxt0d62xFczMaXVP7dz23GZRnnnVlnDwwLB3Tu5fWx10ZSEbj?= =?us-ascii?Q?2pQRB6w7nzFPPbZd3300VjFW4dWFk1bFj1BSYlzIBNVZTqGujdxJO6bpmXuE?= =?us-ascii?Q?YwO34sSSMFZcTeEik0uektpquzTTrVLPEuFARDYMtxpUIDZOHF7h7EN1RJIV?= =?us-ascii?Q?IykmYfLTJ35o0Q+TQbjm8EzoAulv/J51Rmh7H1EvMeVjayIgnzGThJmoBj75?= =?us-ascii?Q?h8mLzaj+s8cD+jmoqYZpxixItS7dPVYw4RrSnw9BEmgCbGX8Xz9UY56OCh/4?= =?us-ascii?Q?kh1ENnSqCKgqOrr6ejq27/KhybZl/2dxTujSkYlKIZYwdtfwGdeNfhXAXT9s?= =?us-ascii?Q?Csxifs6G28tf0KcU74YFe9bIQvmVwZNwzkpRugVIspzI+1RnzZS8tu2xHMSO?= =?us-ascii?Q?bha5t/NNV+gEms/VIn/yMxlS1rI0BlPaXDIT+WR4Zw1HhVTdGbkK1pzBTpEp?= =?us-ascii?Q?w0zvgPNSu3pp1sR4YL7vW0pqbUXwtKWeiLCU6Af9EXrfT1y8PgF8LInn0pp/?= =?us-ascii?Q?26EKYigrnCDWdS54xgkxTu4vkCOPzxheg3HxlsOOuOpaSmSfnmbpDPI7QNzG?= =?us-ascii?Q?0UApKNReF3KH26hTZPomfRK4fky7K7zXUoVCSt32TKLGVfoc85lx611b94E0?= =?us-ascii?Q?5ExA8uNtvAD8aCcYWFKr7oPWxce82x5YCAJSzAyUk3nq08iZ/8+nnMGEBPRi?= =?us-ascii?Q?hB0Owwj9seGqWiHVU/VyE/SMcTUt8OlX/dH7RhoLL5YPpHnGUjQfz1/GJU1y?= =?us-ascii?Q?/u7ZM+LPpy0beowxg6g=3D?= X-Forefront-Antispam-Report: CIP:216.228.117.160;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:dc6edge1.nvidia.com;CAT:NONE;SFS:(13230040)(82310400026)(7416014)(376014)(36860700013)(1800799024);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Oct 2025 00:05:54.9746 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 3b9185ca-84aa-4a27-39a7-08de09ec478c X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.160];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: CY4PEPF0000EE3C.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB6556 Content-Type: text/plain; charset="utf-8" The iommu_deferred_attach() function invokes __iommu_attach_device() while not holding the group->mutex, like other __iommu_attach_device() callers. Though there is no pratical bug being triggered so far, it would be better to apply the same locking to this __iommu_attach_device(), since the IOMMU drivers nowaday are more aware of the group->mutex -- some of them use the iommu_group_mutex_assert() function that could be potentially in the path of an attach_dev callback function invoked by the __iommu_attach_device(). The iommu_deferred_attach() will soon need to invoke a new domain op that must be locked with __iommu_attach_device under group->mutex. So, grab the mutex to guard __iommu_attach_device() like other callers. Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Signed-off-by: Nicolin Chen --- drivers/iommu/iommu.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 2ca990dfbb884..170e522b5bda4 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2185,10 +2185,17 @@ EXPORT_SYMBOL_GPL(iommu_attach_device); =20 int iommu_deferred_attach(struct device *dev, struct iommu_domain *domain) { - if (dev->iommu && dev->iommu->attach_deferred) - return __iommu_attach_device(domain, dev, NULL); + /* + * This is called on the dma mapping fast path so avoid locking. This is + * racy, but we have an expectation that the driver will setup its DMAs + * inside probe while being single threaded to avoid racing. + */ + if (!dev->iommu || !dev->iommu->attach_deferred) + return 0; =20 - return 0; + guard(mutex)(&dev->iommu_group->mutex); + + return __iommu_attach_device(domain, dev, NULL); } =20 void iommu_detach_device(struct iommu_domain *domain, struct device *dev) --=20 2.43.0