From nobody Fri Jun 19 23:43:02 2026 Received: from mx0b-0064b401.pphosted.com (mx0b-0064b401.pphosted.com [205.220.178.238]) (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 CC7D2382F2A; Tue, 21 Apr 2026 07:35:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.178.238 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776756930; cv=fail; b=Yg7KSWPqM7K2396hElocWOf81eBSOq1n26Ko+2wtsjAZ1nC2poQSDDEv0fzANRffzlnOouwCGddTtbFky6o9WRJjnLDipk0RiK+/Sb1uH/1mzgxNpaEqHHh01h0VB2pB13lMsXt96qJ4TqCqLd4TGssxxQW8wnZUDYnIVXjiHkk= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776756930; c=relaxed/simple; bh=ro+NEVngoJwLV3zH9wmio+fSihSxr60pYfH3e0bNFeo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=rdVVrMD0K0EYRU5LAwrsUr1PaBJxTJ4DLcweB49NxxMjcD8t/v3p/8pEJ3zP0vYhQGGNtTVZn8fYU2Z2eFTYSG+2ksOR/Ii98keqnkinxirNHx+k0Y/6JifrK7NYO8uqT7PSJr+WzS3+7I7pJCuuNL9dCK3Vd1Qd4QgdwCeSAFU= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=windriver.com; spf=pass smtp.mailfrom=windriver.com; dkim=pass (2048-bit key) header.d=windriver.com header.i=@windriver.com header.b=ZxejIFVg; arc=fail smtp.client-ip=205.220.178.238 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=windriver.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=windriver.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=windriver.com header.i=@windriver.com header.b="ZxejIFVg" Received: from pps.filterd (m0250811.ppops.net [127.0.0.1]) by mx0a-0064b401.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 63L517X8383621; Tue, 21 Apr 2026 07:34:56 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=windriver.com; h=cc:content-transfer-encoding:content-type:date:from :in-reply-to:message-id:mime-version:references:subject:to; s= PPS06212021; bh=xj1MG6PjxfLHcjimUsHntnROzsCNKvwim/LTNuA+FJ4=; b= ZxejIFVgQWUm7/MTxMZikk7jfRTm++dYQ1S26e70lGX6NFAlx4WJgRWsFXRnehca Xr6ixYIK3XyOunXW2O7RoMVGCEYaBaXoSbAjbdKmpWwK/LzSL7H/rczICgEtT89j XJI0dHvpqzVMwn+2iNGkcjlWg2wfnh5hMJ2eJjVvNgvu27zn76sGDUWpWUoq9nC8 TeBR6EctaGHFc3Erq15OmduUd0WvcuIRuF3Faf9Ur3BrM06uEa263n5L+/7jiCEi VClf9IedAFQRhfOT9b1Prns15vdLvebJpUAb4Q1RNH40vLLGctfg1Q+x37OQ2R2R 0TdI2O39r+JAix5qoOJLqg== Received: from bl2pr02cu003.outbound.protection.outlook.com (mail-eastusazon11011031.outbound.protection.outlook.com [52.101.52.31]) by mx0a-0064b401.pphosted.com (PPS) with ESMTPS id 4dky5yb2vx-1 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 21 Apr 2026 07:34:55 +0000 (GMT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=K0IUNg3gfyO7A4uk9QAEefcuSaQXMMSvebOrbU7wsTB1LMxYhR+37vzYXDiRZsHIE0pdnOeyhBiCkxo2S2cBAixN/tLNLtc4hsRow6Ha2QSN/Q+nyWekvFC4Z7fvwaBHtVEzWsaAC4IDizMPUfPMDFGaRggSb8mj6h85EXQ63Oz1la+3FE+sWe4+3VZgqm97wNVmgL+MaJ1bUtuCnwKxICgUIZUeniHvBg7g8Vhj+hOUwF7COJVQHoRVcEx2H0zxbKIcSbvF58MeVWogCDUILOUQkrg9xpcIa5sVOtnKj8Lu8aXiz9ru4zxLm+RjSGafE9gbX0JEM09RJAn3Cangow== 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=xj1MG6PjxfLHcjimUsHntnROzsCNKvwim/LTNuA+FJ4=; b=TRUG1xI1fA8uiNgMy4jz6pD5EUL/ib6gZnjPfxlQFM4REdpQs1Fg+WYm216sDUvX1DvCj8RjTs5KnKWPkHRhjbVnx7A/YeLfUbUEI+RkeZ6nbkKHkVRseLrosPAGR0Lw4z6Vue1Hgn6cdyA/vQ6QobBhUIi5vjnt52jfZGpCI1eI8dGAA5un8G/mSYH7DqTAmUphnSK07XK01hzRZ6tzuQc5Rw0/md4f7G8HlqKTmzaJMVFoc5fHOa7vIs7ectGUWRzahT2lm3C7Z1+Cj1OVjrnbx7H0tx1KyYdj+xA3atahRP08CQqaB0L0M4KRhlTF+PqWU+DzX6vtv/JVIRqUKQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=windriver.com; dmarc=pass action=none header.from=windriver.com; dkim=pass header.d=windriver.com; arc=none Received: from SJ2PR11MB7546.namprd11.prod.outlook.com (2603:10b6:a03:4cc::8) by SA1PR11MB6782.namprd11.prod.outlook.com (2603:10b6:806:25e::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9846.16; Tue, 21 Apr 2026 07:34:53 +0000 Received: from SJ2PR11MB7546.namprd11.prod.outlook.com ([fe80::ca9b:dcf:8881:bced]) by SJ2PR11MB7546.namprd11.prod.outlook.com ([fe80::ca9b:dcf:8881:bced%4]) with mapi id 15.20.9846.016; Tue, 21 Apr 2026 07:34:53 +0000 From: "Ionut Nechita (Wind River)" To: linux-pci@vger.kernel.org, bhelgaas@google.com Cc: helgaas@kernel.org, sebott@linux.ibm.com, schnelle@linux.ibm.com, bblock@linux.ibm.com, linux@roeck-us.net, lukas@wunner.de, stable@vger.kernel.org, linux-kernel@vger.kernel.org, intel-xe@lists.freedesktop.org, matthew.brost@intel.com, michal.wajdeczko@intel.com, piotr.piorkowski@intel.com, dtatulea@nvidia.com, mani@kernel.org, kbusch@kernel.org, lkml@mageta.org, alifm@linux.ibm.com, julianr@linux.ibm.com, ionut_n2001@yahoo.com, sunlightlinux@gmail.com Subject: [PATCH v13 1/2] PCI/IOV: Make pci_lock_rescan_remove() reentrant and protect sriov_add_vfs/sriov_del_vfs Date: Tue, 21 Apr 2026 10:34:20 +0300 Message-ID: <288517e50996200c368cfe172de86ceb02bbd342.1776756380.git.ionut.nechita@windriver.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: VI1PR0202CA0012.eurprd02.prod.outlook.com (2603:10a6:803:14::25) To SJ2PR11MB7546.namprd11.prod.outlook.com (2603:10b6:a03:4cc::8) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ2PR11MB7546:EE_|SA1PR11MB6782:EE_ X-MS-Office365-Filtering-Correlation-Id: 59dc9201-c35e-4751-9cac-08de9f787a98 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|10070799003|366016|376014|7416014|52116014|22082099003|18002099003|56012099003; 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:SJ2PR11MB7546.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(10070799003)(366016)(376014)(7416014)(52116014)(22082099003)(18002099003)(56012099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 2 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?nUE0ofBkvffITZiC2+Zw6qM25JKcX7/rGztEjnmjPJQN0wbEdwOK6eC/dKZ2?= =?us-ascii?Q?+6gv5bbIfgLIffxtJisjkA1s+RiO9EdyFsDjtT2xPMpdPeACE4T0MC2CrdVc?= =?us-ascii?Q?xI7zKsO6pvWzKCw+44Am2XD/CYHQW5hdYuqQjAIOh707dajuQ+MLLxInVmxk?= =?us-ascii?Q?t+YS1XPKSowYj7PChax/DCYCUSDlDYvIJkwHh5X+C50iQm+3o/gR1SR/me8a?= =?us-ascii?Q?qZyvGId0agTrxJ15XLOzo7A8zhXH25NO8G8JSO0ZZhuPawgOKOf4XX1O1iqp?= =?us-ascii?Q?mAW1ey7DxaPHq/g0fOH2glUOviwef34Ck1f7OUqa0wz8truHHnH0haTWG1Sz?= =?us-ascii?Q?1G7eFie0QJRcJrn3Yyez3Gi3fCTJjjNjlq5WJxD5g/itgPqcSYk6zY/ecD/g?= =?us-ascii?Q?WqABBp8RnblXzOduiT8JFxua0ohVrCSGl9FI6xABlkOUNosAOqkQ7V2222hI?= =?us-ascii?Q?t5+9cVIjv7Rba4AMQmBw2Q/6CCHkQxYy+Lf77aLQe/51kDFOElJPyurBc21P?= =?us-ascii?Q?gtNrWFPTuN54F7aN9lolcaOBCTlScF4skMCWtlr0A8xlIiFk1bGZm+8hLtl8?= =?us-ascii?Q?HUfzwP4uG3OU6gNCNKqEHeLJOMgsYolMCJTWMOiv2WCFoJwzvZkdtQ1gjCsl?= =?us-ascii?Q?4jDBPssnkYqmtMUQG2xryauIvfEEL5JcVZoiPUM9Qt61KoqHh1s72eK5Rpdf?= =?us-ascii?Q?RWRloIDMGELWcjEjQGZKbkU34aQSz5dxUT7fpMu+UIdYi4+Lqol+B/5qkTfL?= =?us-ascii?Q?P9WqdP8LlghweSUm2tnBT4/db7A2FgJXvbtb8UkUwteHWpm0EspsHJ4of5sy?= =?us-ascii?Q?K1oMBiWpcsnZilVkZ56qkHEuWEFifXVTXgKLJf1vJow4ms9VlFevjT9bpNCd?= =?us-ascii?Q?3fHJiMfr6aq8n+VlQpT8NodQcSurMYdPll7hqJPN3J5dGYx+juqYzAhK96E+?= =?us-ascii?Q?kcvgY/IXzKPru9H9c8KP17uvOdf5sZ5PK4EIgRFY8jB/hlRF0ouUD1u1cova?= =?us-ascii?Q?yx8L5QCqohttMmP3Dp+S0JcoA/mm/t99u3vyUmLIhmH4tmvv1b9RWyfXdUf6?= =?us-ascii?Q?9zK6YbFlBd2UJctjPlCk3BgBxzApePOo9DIJSIq3klg5vw/YjynHvDanQFVn?= =?us-ascii?Q?mhe1v9KdGLEu9s6Ps2lqAc3wbiOjWTnk8QcyUk4y0hkyVg8KgsmhVxVpkoNW?= =?us-ascii?Q?VR1qulECTeRwL+khNK6k3YgHThbFdVJq1g3ZuCiAxDjRibax0bktxU6z2bDE?= =?us-ascii?Q?lwndGVjUC+n+ny9rBdIITUQG4YcPPdZPo9gxv10VRuk5xKKzd/gZO6RCSYeD?= =?us-ascii?Q?3WN18kCX0+OqIsM0vM/cAUZi3Haf1cc6XVGHSDyLmgpfP009PM7KKs+MrA6k?= =?us-ascii?Q?0Wbh/mfkxpMYsMre/eNehoKTgTBc6cooRIjKqcSZPOt/mgZAQnBfdyCL5g3w?= =?us-ascii?Q?aK2pwTinLS0+IcfRmtzcTBlm2MssJ8VDb5sC4cJ15XX+1U4vgYtpEp29yEDm?= =?us-ascii?Q?SgftAZZ3oVCv6721XithNpYAwa6DwBJae/WUhJye9ImN493PtTeQTyHoAgZn?= =?us-ascii?Q?moWSpzSspJBvSG8eDJMuOs+gK0T3Ocpm0cG9ZTExvMRQxTA39FOs/ZyaDGTb?= =?us-ascii?Q?FmU0CUXhgq8NZ7UB6u8aGvQGSvnet63CfM7PMVOfI3ywYX+xHsfSUSROEpmn?= =?us-ascii?Q?77Hhi0yJE7mK0rZY3WgJIDxtFaviedz1g9075zYP0P4VU1G8CGMaFxybu/zm?= =?us-ascii?Q?xV2a47q7KAgblbIMLe8YWwdzhiFQdrIoiaO0f/ZYEkHH4a57/Wn48VwgH+GQ?= X-MS-Exchange-AntiSpam-MessageData-1: FF1S+ND4FyBVA2sj5rhiDetPSRs/QscvMJE= X-Exchange-RoutingPolicyChecked: E5yB0sBBZSajDCJnCdyvPYHHFm2KTRysH5Wxi3x6XbQhqQYetDdaOlWbNVhKl0UPBQCbxzhT4ELQu61wwDs1+1x0iGGB2FQZP43rvLM0+bwsFBW9FbWUHV9etI68cJ8lliDFEYSK+2CmkDoPL7/PIxc5+0VN2hu+owj6Sp2seDD5WvrbpaaUGh2fp4lGxnTBcix4QQ+8IlSviSJwSxeObElx0qRaWtASLZkYXwWjg+2lsU6UkReag6TAE7TfIlLHd0Xyvyoiidr0LyuJvEhgNYyEfhv7rAOVPPCZfcFOkoFgs+dpPRuaHESo3oDdS4doxZIbDe9MfCA66JAa33ocWA== X-OriginatorOrg: windriver.com X-MS-Exchange-CrossTenant-Network-Message-Id: 59dc9201-c35e-4751-9cac-08de9f787a98 X-MS-Exchange-CrossTenant-AuthSource: SJ2PR11MB7546.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Apr 2026 07:34:53.6686 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ddb2873-a1ad-4a18-ae4e-4644631433be X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: hBmi0Scw/USkMypXTEKr7ftfY0Ojvnx7nzY8GbBBqAbbzja3YbKAC8/oeOW9Zws23Yq3+xqPMII8RLmQJ1RfSFVqY6S9I79whQVlhOm1ILw= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR11MB6782 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNDIxMDA3MiBTYWx0ZWRfX/QNndMXjkHlu BVLIxZzbEMhuIkWKw5dMWlkbYabmg6cNgrfNHKowTwACX72a03RPH6A7xU3EX8Osp2sjvOBG4ay 5LLy9vh8w72QS/3FIj4fV4IHAOAf6f9Hs+LgbMj10fZRyU+JbE1QOvZf7Eh3bENFDxl/QnoYv38 iFfhGTjjELnokG0i6ecAw/F97404blnyYDZ5ILc1dd96daM2DF3wKwDqngv4On1vNIqAFOsNspP W6XpVXE6GImdzQuh7NjWDgNBIM/6Eh4rJZbA5WsDEL0YRmqlRCHJ5p3ogDDo5DMnAYwKVyq+ESz k2iCDpFPB44dI159HePeAT8NKhdGbexQDmoMBg8y2oE7BI50ta5o/Ct/oWsCi6ramEN/G7f7DGT dBaXzWiq/sH+69hVp5cILzdgDTf8eIEx4iouCBWSyzyDlQCNlnCuDHke8fWcSEvxhOH1lijrUR6 daaFGj5UVDL1heTrQ5g== X-Proofpoint-GUID: WQbKc-ePUuOVm0h7K2y5s1Chu5LpS6Jm X-Proofpoint-ORIG-GUID: WQbKc-ePUuOVm0h7K2y5s1Chu5LpS6Jm X-Authority-Analysis: v=2.4 cv=Bp+tB4X5 c=1 sm=1 tr=0 ts=69e7289f cx=c_pps a=PWz2vMGk566g1z9MD32Dlw==:117 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=z/mQ4Ysz8XfWz/Q5cLBRGdckG28=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=xqWC_Br6kY4A:10 a=A5OVakUREuEA:10 a=VkNPw1HP01LnGYTKEx00:22 a=bi6dqmuHe4P4UrxVR6um:22 a=klDOsUkWDRETUCZYPvoE:22 a=t7CeM3EgAAAA:8 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=hh5_vNSPTWDFZ6TSUYYA:9 a=FdTzh2GWekK77mhwV6Dw:22 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-04-21_01,2026-04-20_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 clxscore=1015 bulkscore=0 phishscore=0 impostorscore=0 malwarescore=0 priorityscore=1501 lowpriorityscore=0 adultscore=0 suspectscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2604070000 definitions=main-2604210072 Content-Type: text/plain; charset="utf-8" From: Ionut Nechita After reverting commit 05703271c3cd ("PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV") and moving the lock to sriov_numvfs_store(), the path through driver .remove() (e.g. rmmod, or manual unbind) that calls pci_disable_sriov() directly remains unprotected against concurrent hotplug events. This affects any SR-IOV capable driver that calls pci_disable_sriov() from its .remove() callback (i40e, ice, mlx5, bnxt, etc.). On s390, platform-generated hot-unplug events for VFs can race with sriov_del_vfs() when a PF driver is being unloaded. The platform event handler takes pci_rescan_remove_lock, but sriov_del_vfs() does not, leading to double removal and list corruption. We cannot use a plain mutex_lock() here because sriov_del_vfs() may also be called from paths that already hold pci_rescan_remove_lock (e.g. remove_store -> pci_stop_and_remove_bus_device_locked, or sriov_numvfs_store with the lock taken by the previous patch). Using mutex_lock() in those cases would deadlock. Make pci_lock_rescan_remove() itself reentrant by tracking the current owner task and a recursion depth counter, as suggested by Lukas Wunner and Benjamin Block, since these recursive locking scenarios exist elsewhere in the PCI subsystem: - If the lock is already held by the current task (owner =3D=3D current): increments the depth counter and returns without re-acquiring, avoiding deadlock. - If the lock is held by another task: blocks until the lock is released, then records the owner and sets depth to 1. - If the lock is not held: acquires the mutex normally. pci_unlock_rescan_remove() decrements the depth counter and releases the mutex (clearing the owner) only when the depth reaches zero. A WARN_ON catches mismatched unlock calls from tasks that do not own the lock. This avoids relying on mutex_get_owner(), which is not exported to modules and caused link failures for builds that inline this code outside of the core kernel image. This approach keeps the API unchanged: callers simply pair lock/unlock calls without needing to track any return value or use separate reentrant variants. Add pci_lock_rescan_remove()/pci_unlock_rescan_remove() calls to sriov_add_vfs() and sriov_del_vfs() to protect VF addition and removal against concurrent hotplug events. Remove the rescan/remove locking from sriov_numvfs_store() that was introduced by commit a5338e365c45 ("PCI/IOV: Fix race between SR-IOV enable/disable and hotplug"), since the locking is now handled directly in sriov_add_vfs() and sriov_del_vfs() where it is actually needed, reducing the lock scope. Fixes: 18f9e9d150fc ("PCI/IOV: Factor out sriov_add_vfs()") Fixes: 05703271c3cd ("PCI/IOV: Add PCI rescan-remove locking when enabling/= disabling SR-IOV") Fixes: a5338e365c45 ("PCI/IOV: Fix race between SR-IOV enable/disable and h= otplug") Cc: stable@vger.kernel.org Suggested-by: Lukas Wunner Suggested-by: Benjamin Block Signed-off-by: Ionut Nechita Reviewed-by: Benjamin Block Tested-by: Benjamin Block --- drivers/pci/iov.c | 9 +++++---- drivers/pci/probe.c | 18 ++++++++++++++++-- 2 files changed, 21 insertions(+), 6 deletions(-) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 91ac4e37ecb9..7ed902539051 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -495,9 +495,7 @@ static ssize_t sriov_numvfs_store(struct device *dev, =20 if (num_vfs =3D=3D 0) { /* disable VFs */ - pci_lock_rescan_remove(); ret =3D pdev->driver->sriov_configure(pdev, 0); - pci_unlock_rescan_remove(); goto exit; } =20 @@ -509,9 +507,7 @@ static ssize_t sriov_numvfs_store(struct device *dev, goto exit; } =20 - pci_lock_rescan_remove(); ret =3D pdev->driver->sriov_configure(pdev, num_vfs); - pci_unlock_rescan_remove(); if (ret < 0) goto exit; =20 @@ -633,15 +629,18 @@ static int sriov_add_vfs(struct pci_dev *dev, u16 num= _vfs) if (dev->no_vf_scan) return 0; =20 + pci_lock_rescan_remove(); for (i =3D 0; i < num_vfs; i++) { rc =3D pci_iov_add_virtfn(dev, i); if (rc) goto failed; } + pci_unlock_rescan_remove(); return 0; failed: while (i--) pci_iov_remove_virtfn(dev, i); + pci_unlock_rescan_remove(); =20 return rc; } @@ -766,8 +765,10 @@ static void sriov_del_vfs(struct pci_dev *dev) struct pci_sriov *iov =3D dev->sriov; int i; =20 + pci_lock_rescan_remove(); for (i =3D 0; i < iov->num_VFs; i++) pci_iov_remove_virtfn(dev, i); + pci_unlock_rescan_remove(); } =20 static void sriov_disable(struct pci_dev *dev) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index b63cd0c310bc..0e62081bc5e5 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -3513,16 +3513,30 @@ EXPORT_SYMBOL_GPL(pci_rescan_bus); * routines should always be executed under this mutex. */ DEFINE_MUTEX(pci_rescan_remove_lock); +static struct task_struct *pci_rescan_remove_owner; +static unsigned int pci_rescan_remove_depth; =20 void pci_lock_rescan_remove(void) { - mutex_lock(&pci_rescan_remove_lock); + if (pci_rescan_remove_owner =3D=3D current) { + pci_rescan_remove_depth++; + } else { + mutex_lock(&pci_rescan_remove_lock); + pci_rescan_remove_owner =3D current; + pci_rescan_remove_depth =3D 1; + } } EXPORT_SYMBOL_GPL(pci_lock_rescan_remove); =20 void pci_unlock_rescan_remove(void) { - mutex_unlock(&pci_rescan_remove_lock); + if (WARN_ON(pci_rescan_remove_owner !=3D current)) + return; + + if (--pci_rescan_remove_depth =3D=3D 0) { + pci_rescan_remove_owner =3D NULL; + mutex_unlock(&pci_rescan_remove_lock); + } } EXPORT_SYMBOL_GPL(pci_unlock_rescan_remove); =20 --=20 2.53.0 From nobody Fri Jun 19 23:43:02 2026 Received: from mx0b-0064b401.pphosted.com (mx0b-0064b401.pphosted.com [205.220.178.238]) (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 E579E38A706; Tue, 21 Apr 2026 07:35:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.178.238 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776756935; cv=fail; b=Nhpwk6jo7+BYuMR7aHxa3tSqpG1wOHaNeEL28f3R5zrFhTG7j9cn/Xjp97XYS8hkG4dMmmVR6IL+hBSXPDeuwo5soe1O6xhHrupg3u6G7SSNTJuEZ1J4niOpWc6mx4aAr5kZGSccbcnMCEvZIc7LJfp8UzqYCbUYl0ke6lHY+Nw= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776756935; c=relaxed/simple; bh=vrJgq2ubLedxXwnejb8xqvFNi+iBVzJof5NUXTpqQ60=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=XrcdaWOcBmHtBuAY7l4TmjiloHePWnWj7G/SoN/AP1mCkzLvBOajgAB1zrjPH4gzV32dJFY2+9Ro6y0wRn/ENU8vbbICCd+r/clQU5oUe7MIne2RzH0UfCeqqqDLo7sZhi7bq8y9DzugH/IxC5JZxa463Yxd2TxoLQauuQxuU7A= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=windriver.com; spf=pass smtp.mailfrom=windriver.com; dkim=pass (2048-bit key) header.d=windriver.com header.i=@windriver.com header.b=IytWxjgV; arc=fail smtp.client-ip=205.220.178.238 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=windriver.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=windriver.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=windriver.com header.i=@windriver.com header.b="IytWxjgV" Received: from pps.filterd (m0250811.ppops.net [127.0.0.1]) by mx0a-0064b401.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 63L517XA383621; Tue, 21 Apr 2026 07:35:08 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=windriver.com; h=cc:content-transfer-encoding:content-type:date:from :in-reply-to:message-id:mime-version:references:subject:to; s= PPS06212021; bh=edruRNhOFxoTqLpoRttq5X20SXLnytn48rYp1IqcNcs=; b= IytWxjgVsJQbDcB4kEcA4bNxTQLPiAoL8YBOk/BjeOGUJ8ZQEHVTIoWDZzarj7YR wvuQNmBUlAD+OksRMGb8dtfQyHKxJMZdeAJ7DU6nNQ7jny6tBNBeRlxA3+fHOQgz rInYoNSBWxFlpKrMO7hMtZFLh7ijCbk7XW4ZCvXYsgJMLBRVg42iRZMYBavHUOPg aEtyiKm/VJ9dnSq8G+3f7YQqMto9JL5d/IAWjtwHko24aw1dTSn4c54SASt2bfWQ 05t0zTRCn0ySC8uEqRVstjboaae5rf1PvZm6VQX5ULQ1XM2KHX611UsAbxqDVSXb xnwwGY8EmfkodN6BBdClvg== Received: from bl2pr02cu003.outbound.protection.outlook.com (mail-eastusazon11011009.outbound.protection.outlook.com [52.101.52.9]) by mx0a-0064b401.pphosted.com (PPS) with ESMTPS id 4dky5yb2w8-1 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 21 Apr 2026 07:35:07 +0000 (GMT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=I6TKjxpQU5nu+bM17pmeNhTue5lE2+/OlzDAKiR+2sizhCB6GUvK/TEWHtIyZkC9WAddrOi4OSV3YV2ptnmuac3+hjLpytjH+1jwm+8SP+JQPB+Mjix2imbrhrY0hZ5OSdQs/odxq8BJ0sKiVkVEjk/MIZkT6HX3QTu101fzUOvOHNwrJJ0L7DPMM6kwrQhLqoScD029/gaI/DoVcWz4yeadrJ+U/563+Uggl7urB2oPbxgOei14ZaMaOotgNtupdg79LxE5xklVuXUHTnTuIswVTRWN/fqvnAxJWv4+5WSSpOIcy21FY8ALHY2N2KxefU0kDQUOnTK3HzMtIre7FA== 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=edruRNhOFxoTqLpoRttq5X20SXLnytn48rYp1IqcNcs=; b=JWHjZ9uzt6AgrvU9Jc4Lne/6yLXxfKPD5i1qlQ8xDuwdWn8+1APipM8AGZcKuTb9G7xwhhdC+jQUoSGuKaxiSuT0yrfuSgBiPC5/zAmXyVcMeF6llgiG821/aiMFKDL9Va6+N7f8VvYPXmLVXrKxFEWBlT9p6CX1Fnlkf6iHUqV/OnRZwVowXrZf/zinThkD1DyB7Ee7ycCBjaNwRbBImdp/O0QmBmwKIdwWbTO4fEut2L2vSfiiQA/2mIsURGHNK4aZ44Ucj1HAV382PpUT94ex4OaymkBZFp4QoA+igjLRUQbDY+yEskgpBYj6LI7bLLoIkla7dTmMFoE4ChkXnQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=windriver.com; dmarc=pass action=none header.from=windriver.com; dkim=pass header.d=windriver.com; arc=none Received: from SJ2PR11MB7546.namprd11.prod.outlook.com (2603:10b6:a03:4cc::8) by SA1PR11MB6782.namprd11.prod.outlook.com (2603:10b6:806:25e::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9846.16; Tue, 21 Apr 2026 07:35:05 +0000 Received: from SJ2PR11MB7546.namprd11.prod.outlook.com ([fe80::ca9b:dcf:8881:bced]) by SJ2PR11MB7546.namprd11.prod.outlook.com ([fe80::ca9b:dcf:8881:bced%4]) with mapi id 15.20.9846.016; Tue, 21 Apr 2026 07:35:05 +0000 From: "Ionut Nechita (Wind River)" To: linux-pci@vger.kernel.org, bhelgaas@google.com Cc: helgaas@kernel.org, sebott@linux.ibm.com, schnelle@linux.ibm.com, bblock@linux.ibm.com, linux@roeck-us.net, lukas@wunner.de, stable@vger.kernel.org, linux-kernel@vger.kernel.org, intel-xe@lists.freedesktop.org, matthew.brost@intel.com, michal.wajdeczko@intel.com, piotr.piorkowski@intel.com, dtatulea@nvidia.com, mani@kernel.org, kbusch@kernel.org, lkml@mageta.org, alifm@linux.ibm.com, julianr@linux.ibm.com, ionut_n2001@yahoo.com, sunlightlinux@gmail.com Subject: [PATCH v13 2/2] PCI: Fix AB-BA deadlock between device_lock and pci_rescan_remove_lock in remove_store Date: Tue, 21 Apr 2026 10:34:21 +0300 Message-ID: <4625becce42253d53a615efccc33c7d91ccf5312.1776756380.git.ionut.nechita@windriver.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: VI1PR0202CA0012.eurprd02.prod.outlook.com (2603:10a6:803:14::25) To SJ2PR11MB7546.namprd11.prod.outlook.com (2603:10b6:a03:4cc::8) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ2PR11MB7546:EE_|SA1PR11MB6782:EE_ X-MS-Office365-Filtering-Correlation-Id: b322aa95-719b-4548-91a6-08de9f788163 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|10070799003|366016|376014|7416014|52116014|22082099003|18002099003|56012099003; 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:SJ2PR11MB7546.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(10070799003)(366016)(376014)(7416014)(52116014)(22082099003)(18002099003)(56012099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 2 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?qIsFhG+03X+RkczgDjwIpjmpZcmuMYgdaARTLFZi7FKjAwde6w2Bs18TqNrj?= =?us-ascii?Q?ctfJbWw2f7/D+t5vw5pbCo0p1YfIOqKEhU/uBQr8/ozkz53ltYYJbgNTGUts?= =?us-ascii?Q?7Vq5VY54ay30+pC2X3s1In0rlVWNyi7udoqXps1M5vOAgunUf3beaguQ2s/s?= =?us-ascii?Q?adGqRuQgS0Vg5pvjHCNvAskGM2yJEzlbclI1ndbqVY814o62ZDgCiGqFZh4I?= =?us-ascii?Q?7jZJZntlWzaat9wVajWkKhlYbhU1EYdg+RjVk7IQccveIPythMlK0lI16AIW?= =?us-ascii?Q?asfZQjwqdiTcqb7Sjh94Q+yM1/DR6GTp+htPRtAypOAX2FSV0c7iR4NMlWFi?= =?us-ascii?Q?csIwThPnfnWNupcl+hmwVz/V+nqlSYpbCy3GyMZTqeNbjDRNWLlbiS2lvpbR?= =?us-ascii?Q?moSYcmwZo+jAsIuKlm1zhprL22qsaRaZLRiTlsPamSHcgNCxEu/g0Q7gqdH7?= =?us-ascii?Q?aMSqgCytP2WWNHPsb6sOKAn0t3UeMikNO/9ksiy5cC2esVLwBzsSjX+Cfh5g?= =?us-ascii?Q?T5t150qeIuDJIoInmYVj0BdJQyfvv+551alKiDRxmbnntbfZMU8EE4AaGKIV?= =?us-ascii?Q?Js0AbT7WFGH+Ywv96K8CuE/4UBWc+gKwx7djAMojFW3pufwh8KHmQsm30Cxu?= =?us-ascii?Q?07tgHFh4m6F/tebdsGt96KRiGtDYV/3qssGQPd7gB6m+f8zXZX2FyKco6Ss+?= =?us-ascii?Q?S4kaq4wYm78Rfxr+mPIrIYMkdksNB5Z3X3tDGiUQX+3wAMHX84zx7JNb76Gm?= =?us-ascii?Q?x63vFZ4mPCb4t7dNO7voCQuIks26yfB8PVm0MgEiUw8vMhTCLl+3P6ywMBIh?= =?us-ascii?Q?lHCizYeBQpJAbXI7obXQ1Nd7ohg1q7rLQB8dQ8cHVK3j5MY4QFqUQHBj5c8l?= =?us-ascii?Q?z51vUvv/lilAeQOlRfNlZB83Dsk5luxNLPsQpcEUa+CSJWyuvoNuJbK9Wiv2?= =?us-ascii?Q?uo1sNC4arbVbIB2hMG7F1pvFsF2fWOMf0Fv5saYrY4My/7w9Ij6IiF2iZ97W?= =?us-ascii?Q?xz5igjddReY4MyZUTJk/EJjVbLaGCcxxH8XNuA+/xCDezTBBjqPR9eThyj1M?= =?us-ascii?Q?oOxDg3GTxsmk+XXtWrRTpk72rGeJ1eYkOD14S54zChGRCmT6aXE7whKPxxoj?= =?us-ascii?Q?U0ErgYGgE/scDI0fZ8zm5OHUfpUYpaZmMyND59hJwnITxA5AwiNvpIIPU7y8?= =?us-ascii?Q?IZyrDtXU0G8PXe6RBknQF2dmaQwwemPSsziVjx+k4T0d++f1Ynb8Rh0+ZKKh?= =?us-ascii?Q?hx6KiGikKy7ESnnwhZ+o6FgDPa0jMRG10tjOrWqIFeKp1Zmnp2dKKxlbm3N+?= =?us-ascii?Q?eQ6IirgtzVCM16liO+a+toD34UfoxPW+ChiCS9Ex1qsEPNhdOa7vLQ62Z6xD?= =?us-ascii?Q?ashOqndS6rKS/8I/cERmABXVV8sbvSHVsV4P1/uxfN6Vy2zhawD2Oqj+dzQe?= =?us-ascii?Q?Q6LNMNgxswBeVAXHVIZTMKyVjE3zvwUo/WHlxGGPsh8CXEsJzydEGKa0BVf5?= =?us-ascii?Q?V3f6eab4mMObyuDiR8kg15GB3Nj6EeV63Cdi6tfeRgLKOix9hi+6RymgF5bM?= =?us-ascii?Q?MCklLNyWmclZUlBAtB+Hq800HMRCxjqNEdiU+vvfj5qmVVM0IOMPbRWJb3fJ?= =?us-ascii?Q?bHnFIyfsL674CSOsGd6DoNs7AjRGeCD9+92noOTSDdsE25HRrUjkNSjCHasE?= =?us-ascii?Q?GNqHHGlqr205LW4s3k9mZrg3N8XQJYR6wUlQ/1/SPK3JjJdjHWx1sDd8/5A/?= =?us-ascii?Q?3hR1Re7FsGHdd56EYKaV9VJj0gtEP7G57mU2sU66WmzGXjVRGwIMK/4WjXLR?= X-MS-Exchange-AntiSpam-MessageData-1: lNLvL5G5sRH75Q9rvT0luTJlPFyjJYplDF0= X-Exchange-RoutingPolicyChecked: cUgMvsmkn7RwUUZjhdc+BwIi7J2bOdLgy/W9zgYyBDaZlI8MAf5YhAqPhK4/a5ytl8ysiKmbAsQexH9KMFGaL+AFJaT1bTwaxx7sU3g5tvkRtS7DAoODycs54Xe8PTuqAlZ6uQL+7FkCy/qm9Hcysql/G1OY+aGJJKGIx22lLO9jkeH8t5VHeclYxcsfFKBdLpRTzaLL6bnrZ2rN9sYLNDFNHgEtWE3iq83k3Vl/Ys7zJeacchj4i6aLs2on2QF/5oumXqa4yIVvX5fgcxfzMEl+tpaZI/C6m0S9iRhsxGBkGC7mP4Vw5T28vZAuzXnpcwe7Z+81cMe6f10ZTjqH6A== X-OriginatorOrg: windriver.com X-MS-Exchange-CrossTenant-Network-Message-Id: b322aa95-719b-4548-91a6-08de9f788163 X-MS-Exchange-CrossTenant-AuthSource: SJ2PR11MB7546.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Apr 2026 07:35:05.3123 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ddb2873-a1ad-4a18-ae4e-4644631433be X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: uD+5SDO3LjsamFw6qTEV1ulOvyB4q2FMrA7HbALqx/GZduqq9+7HQZh5j5naOKGv3wuU8S6MCMNnub+2MfUjXkAa1RGGKDs3yMBRny8RzI4= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR11MB6782 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNDIxMDA3MiBTYWx0ZWRfX2p5mXAUlYOao ooRrVfpKuc2zcgJRYqEXKwQF0p5bIMbXJFvlfdwTi+U88LphqAx3s9WqpqZ/U450eK6VcQYJ8Ri gvtDATHf9ouuA8piWlMWYsY/rXsWmNOvVXAkJatMb4BFFLQB1Dk5YoxCgrugBmauHT/iW1H1glV Ql03hUn+2fOv/ePp4RWwppDGA/tyx2UG4/1awqrMc6BVlC/2SY28/Ia3m40lx8OOUaxhq98ktoL kc4Qqc2hmhZfdhW4uKgmZNwQQoYkmNAmvh3LRQ1KeyNy/69O1KwEeSHp0TrB8jgMLlLEXZXGczC dkXrew3Zjy4vizarzHWYO/Wln9+0DmPlwiAYRP2nCZW1HvFmuwJZB79Fd0FGHq/oeh71KHPTa5u zewOFsN36bTG2tZxlIVrO3GpRbunlPcQ3D6eoGvZCoZmtf05sh7T9nIz2YIUvfGzjLl0uXARjtT N8kYC/wOksWlQhOQejQ== X-Proofpoint-GUID: Qq-YpKawnwfepJfF_sJUImX8aEjDOSNQ X-Proofpoint-ORIG-GUID: Qq-YpKawnwfepJfF_sJUImX8aEjDOSNQ X-Authority-Analysis: v=2.4 cv=Bp+tB4X5 c=1 sm=1 tr=0 ts=69e728ab cx=c_pps a=kBTuJkHEWKOaoYTOH1TR3A==:117 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=z/mQ4Ysz8XfWz/Q5cLBRGdckG28=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=xqWC_Br6kY4A:10 a=A5OVakUREuEA:10 a=VkNPw1HP01LnGYTKEx00:22 a=bi6dqmuHe4P4UrxVR6um:22 a=klDOsUkWDRETUCZYPvoE:22 a=VwQbUJbxAAAA:8 a=_jlGtV7tAAAA:8 a=p2eoyRXnAAAA:8 a=t7CeM3EgAAAA:8 a=VnNF1IyMAAAA:8 a=mm2UkWPFonPHBTd3Hn4A:9 a=nlm17XC03S6CtCLSeiRr:22 a=KSHYvF9M28j0gckGFaEs:22 a=FdTzh2GWekK77mhwV6Dw:22 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-04-21_01,2026-04-20_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 clxscore=1015 bulkscore=0 phishscore=0 impostorscore=0 malwarescore=0 priorityscore=1501 lowpriorityscore=0 adultscore=0 suspectscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2604070000 definitions=main-2604210072 Content-Type: text/plain; charset="utf-8" From: Ionut Nechita remove_store() calls pci_stop_and_remove_bus_device_locked() which takes pci_rescan_remove_lock first, then device_lock during driver release. Meanwhile, unbind_store() takes device_lock first (via device_driver_detach), and the driver's .remove() callback may call pci_disable_sriov() -> sriov_del_vfs() -> pci_lock_rescan_remove(). This creates an AB-BA deadlock: CPU0 (remove_store) CPU1 (unbind_store) -------------------- -------------------- pci_lock_rescan_remove() device_lock() driver .remove() sriov_del_vfs() pci_lock_rescan_remove() <-- WAITS pci_stop_bus_device() device_release_driver() device_lock() <-- WAITS Fix this by first marking the device as dead using kill_device() to prevent any new driver from binding, then calling device_release_driver() before pci_stop_and_remove_bus_device_locked(). Marking the device dead closes the race window between unbinding and removal where a new driver could theoretically bind: once the dead flag is set, the device core will refuse any new driver probe. After device_release_driver() returns, the driver is already unbound, so the subsequent device_release_driver() call inside pci_stop_and_remove_bus_device_locked() becomes a no-op. Fixes: a5338e365c45 ("PCI/IOV: Fix race between SR-IOV enable/disable and h= otplug") Reported-by: Guenter Roeck Closes: https://lore.kernel.org/linux-pci/0ca9e675-478c-411d-be32-e2d814392= 88f@roeck-us.net/ Reported-by: Benjamin Block Closes: https://lore.kernel.org/linux-pci/20260317090149.GA3835708@chlorum.= ategam.org/ Suggested-by: Benjamin Block Cc: stable@vger.kernel.org Reviewed-by: Niklas Schnelle Reviewed-by: Benjamin Block Tested-by: Benjamin Block Signed-off-by: Ionut Nechita --- drivers/pci/pci-sysfs.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index d37860841260..1426328e9f05 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -521,8 +521,36 @@ static ssize_t remove_store(struct device *dev, struct= device_attribute *attr, if (kstrtoul(buf, 0, &val) < 0) return -EINVAL; =20 - if (val && device_remove_file_self(dev, attr)) + if (val && device_remove_file_self(dev, attr)) { + /* + * Mark the device as dead so that no new driver can bind + * between the unbind and the removal below. Once the + * dead flag is set, the device core will refuse any new + * driver probe. + */ + device_lock(dev); + kill_device(dev); + device_unlock(dev); + + /* + * Unbind the driver before removing the device to avoid + * an AB-BA deadlock between device_lock and + * pci_rescan_remove_lock. Without this, remove_store + * takes pci_rescan_remove_lock first (via + * pci_stop_and_remove_bus_device_locked) and then + * device_lock during driver release, while a concurrent + * unbind_store (or sriov_numvfs_store) takes device_lock + * first and then pci_rescan_remove_lock (via + * sriov_del_vfs), creating a circular dependency. + * + * By unbinding first, the driver's .remove() callback + * (including any SR-IOV VF cleanup) completes before + * pci_rescan_remove_lock is acquired, ensuring both + * paths take locks in the same order. + */ + device_release_driver(dev); pci_stop_and_remove_bus_device_locked(to_pci_dev(dev)); + } return count; } static DEVICE_ATTR_IGNORE_LOCKDEP(remove, 0220, NULL, --=20 2.53.0