From 06f8174a97822f6befd28fc2dd315b43b82c700f Mon Sep 17 00:00:00 2001 From: Shiraz Saleem Date: Mon, 17 Jul 2017 14:03:50 -0500 Subject: [PATCH] IB/core: Protect sysfs entry on ib_unregister_device ib_unregister_device is not protecting removal of sysfs entries. A call to ib_register_device in that window can result in duplicate sysfs entry warning. Move mutex_unlock to after ib_device_unregister_sysfs to protect against sysfs entry creation. This issue is exposed during driver load/unload stress test. WARNING: CPU: 5 PID: 4445 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x5f/0x70 sysfs: cannot create duplicate filename '/class/infiniband/i40iw0' Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./Q87M-D2H BIOS F7 01/17/2014 Workqueue: i40e i40e_service_task [i40e] Call Trace: dump_stack+0x67/0x98 __warn+0xcc/0xf0 warn_slowpath_fmt+0x4a/0x50 ? kernfs_path_from_node+0x4b/0x60 sysfs_warn_dup+0x5f/0x70 sysfs_do_create_link_sd.isra.2+0xb7/0xc0 sysfs_create_link+0x20/0x40 device_add+0x28c/0x600 ib_device_register_sysfs+0x58/0x170 [ib_core] ib_register_device+0x325/0x570 [ib_core] ? i40iw_register_rdma_device+0x1f4/0x400 [i40iw] ? kmem_cache_alloc_trace+0x143/0x330 ? __raw_spin_lock_init+0x2d/0x50 i40iw_register_rdma_device+0x2dc/0x400 [i40iw] i40iw_open+0x10a6/0x1950 [i40iw] ? i40iw_open+0xeab/0x1950 [i40iw] ? i40iw_make_cm_node+0x9c0/0x9c0 [i40iw] i40e_client_subtask+0xa4/0x110 [i40e] i40e_service_task+0xc2d/0x1320 [i40e] process_one_work+0x203/0x710 ? process_one_work+0x16f/0x710 worker_thread+0x126/0x4a0 ? trace_hardirqs_on+0xd/0x10 kthread+0x112/0x150 ? process_one_work+0x710/0x710 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x2e/0x40 ---[ end trace fd11b69e21ea7653 ]--- Couldn't register device i40iw0 with driver model Signed-off-by: Shiraz Saleem Signed-off-by: Sindhu Devale Signed-off-by: Doug Ledford --- drivers/infiniband/core/device.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c index a5dfab6adf49..221468f77128 100644 --- a/drivers/infiniband/core/device.c +++ b/drivers/infiniband/core/device.c @@ -537,10 +537,11 @@ void ib_unregister_device(struct ib_device *device) } up_read(&lists_rwsem); - mutex_unlock(&device_mutex); - ib_device_unregister_rdmacg(device); ib_device_unregister_sysfs(device); + + mutex_unlock(&device_mutex); + ib_cache_cleanup_one(device); ib_security_destroy_port_pkey_list(device); -- 2.20.1