rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5951/1:b..l P5878/1:b..l rcu: (detected by 0, t=10503 jiffies, g=57225, q=2725 ncpus=2) task:kworker/0:4 state:R running task stack:23592 pid:5878 tgid:5878 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7109 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_is_watching+0x83/0xc0 kernel/rcu/tree.c:748 Code: c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02 83 e0 01 65 ff 0d 10 96 2e 12 74 07 5b <5d> c3 cc cc cc cc e8 32 fb 8a ff 5b 5d c3 cc cc cc cc 48 89 df e8 RSP: 0018:ffffc9000567f1e8 EFLAGS: 00000286 RAX: 0000000000000001 RBX: ffffffff8e5c4e00 RCX: ffffc9001a1c1000 RDX: 0000000000000000 RSI: ffffffff8c1573e0 RDI: ffffffff8df3dda0 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff822b4cf6 R13: 0000000000000004 R14: 0000000000090fe8 R15: 0000000000000002 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x201/0x2f0 kernel/locking/lockdep.c:5882 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] __update_page_owner_free_handle.constprop.0+0x31b/0x4a0 mm/page_owner.c:283 __reset_page_owner+0x93/0x1a0 mm/page_owner.c:309 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3186 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4204 __kernfs_new_node+0xd2/0x8e0 fs/kernfs/dir.c:637 kernfs_new_node+0x13c/0x1e0 fs/kernfs/dir.c:713 __kernfs_create_file+0x53/0x350 fs/kernfs/file.c:1039 sysfs_add_file_mode_ns+0x207/0x3c0 fs/sysfs/file.c:319 create_files fs/sysfs/group.c:76 [inline] internal_create_group+0x578/0xf30 fs/sysfs/group.c:183 internal_create_groups+0x9d/0x150 fs/sysfs/group.c:223 device_add_groups drivers/base/core.c:2839 [inline] device_add_attrs drivers/base/core.c:2914 [inline] device_add+0x77f/0x1a70 drivers/base/core.c:3646 usb_new_device+0xd07/0x1a20 drivers/usb/core/hub.c:2694 hub_port_connect drivers/usb/core/hub.c:5566 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x2f34/0x4fe0 drivers/usb/core/hub.c:5952 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:kworker/0:9 state:R running task stack:15832 pid:5951 tgid:5951 ppid:2 task_flags:0x4208160 flags:0x00004000 Workqueue: events nsim_fib_event_work Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7109 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline] RIP: 0010:stack_access_ok+0x0/0x200 arch/x86/kernel/unwind_orc.c:393 Code: 20 ff ff ff 44 8b 85 30 ff ff ff e9 ba fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <48> b8 00 00 00 00 00 fc ff df 41 57 41 56 4c 8d 77 08 41 55 41 54 RSP: 0018:ffffc90005857638 EFLAGS: 00000283 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff913e3446 RDX: 0000000000000008 RSI: ffffc900058576d0 RDI: ffffc90005857700 RBP: ffffc900058576d0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000006afc R12: ffffc90005857750 R13: ffffc90005857700 R14: ffffc90005857700 R15: ffffc90005857734 deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline] unwind_next_frame+0x15c5/0x20a0 arch/x86/kernel/unwind_orc.c:648 __unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3186 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:385 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] nsim_fib6_rt_nh_add+0x4a/0x290 drivers/net/netdevsim/fib.c:500 nsim_fib6_rt_create drivers/net/netdevsim/fib.c:562 [inline] nsim_fib6_rt_insert drivers/net/netdevsim/fib.c:752 [inline] nsim_fib6_event drivers/net/netdevsim/fib.c:856 [inline] nsim_fib_event drivers/net/netdevsim/fib.c:889 [inline] nsim_fib_event_work+0x196a/0x2e80 drivers/net/netdevsim/fib.c:1493 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245