======================================
| [   44.900661][    C0] 1 lock held by ksoftirqd/0/14:
| [ 44.900837][ C0] #0: ffffffff8ab75140 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2562) 
| [   44.901149][    C0]
| [   44.901149][    C0] stack backtrace:
[   44.901371][    C0] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   44.901373][    C0] Call Trace:
[   44.901375][    C0]  <TASK>
[ 44.901377][ C0] dump_stack_lvl (lib/dump_stack.c:123) 
[ 44.901382][ C0] print_usage_bug.part.0 (kernel/locking/lockdep.c:4046) 
[ 44.901387][ C0] mark_lock_irq (kernel/locking/lockdep.c:4011 kernel/locking/lockdep.c:4057 kernel/locking/lockdep.c:4268) 
[ 44.901392][ C0] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 44.901397][ C0] ? save_trace (kernel/locking/lockdep.c:594) 
[ 44.901401][ C0] mark_lock (kernel/locking/lockdep.c:4754) 
[ 44.901404][ C0] mark_usage (kernel/locking/lockdep.c:4643) 
[ 44.901407][ C0] __lock_acquire (kernel/locking/lockdep.c:5189) 
[ 44.901412][ C0] lock_acquire.part.0 (kernel/locking/lockdep.c:472 kernel/locking/lockdep.c:5868) 
[ 44.901415][ C0] ? simple_pin_fs (fs/libfs.c:1066) 
[ 44.901419][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 44.901423][ C0] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5829) 
[ 44.901426][ C0] ? simple_pin_fs (fs/libfs.c:1066) 
[ 44.901429][ C0] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 44.901432][ C0] ? simple_pin_fs (fs/libfs.c:1066) 
[ 44.901435][ C0] simple_pin_fs (fs/libfs.c:1066) 
[ 44.901438][ C0] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 44.901441][ C0] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 44.901447][ C0] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 44.901450][ C0] ? __sk_destruct (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/net_namespace.h:287 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 44.901455][ C0] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 44.901458][ C0] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 44.901461][ C0] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 44.901466][ C0] ? kthread (kernel/kthread.c:464) 
[ 44.901469][ C0] ? ret_from_fork (arch/x86/kernel/process.c:153) 
[ 44.901472][ C0] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 44.901474][ C0] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2417) 
[ 44.901478][ C0] ? __pfx_migrate_enable (kernel/sched/core.c:2392) 
[ 44.901484][ C0] __put_net (net/core/net_namespace.c:732) 
[ 44.901487][ C0] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 44.901491][ C0] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 44.901494][ C0] rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 44.901498][ C0] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 44.901502][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 44.901505][ C0] ? note_gp_changes (kernel/rcu/tree.c:1324 (discriminator 1)) 
[ 44.901508][ C0] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 44.901514][ C0] rcu_core (kernel/rcu/tree.c:2826) 
[ 44.901519][ C0] handle_softirqs (kernel/softirq.c:580) 
[ 44.901523][ C0] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 44.901527][ C0] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 44.901530][ C0] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 44.901534][ C0] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 44.901538][ C0] kthread (kernel/kthread.c:464) 
[ 44.901541][ C0] ? __pfx_kthread (kernel/kthread.c:413) 
[ 44.901543][ C0] ? ret_from_fork (arch/x86/kernel/process.c:152) 
[ 44.901545][ C0] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 44.901549][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 44.901552][ C0] ? __pfx_kthread (kernel/kthread.c:413) 
[ 44.901555][ C0] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 44.901558][ C0] ? __pfx_kthread (kernel/kthread.c:413) 
[ 44.901560][ C0] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   44.913620][    C0] RCU nest depth: 0, expected: 0
| [   44.913796][    C0] INFO: lockdep is turned off.
| [   44.913963][    C0] Preemption disabled at:
| [ 44.913964][ C0] handle_softirqs (kernel/softirq.c:553) 
[   44.914389][    C0] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   44.914390][    C0] Call Trace:
[   44.914392][    C0]  <TASK>
[ 44.914394][ C0] dump_stack_lvl (lib/dump_stack.c:123) 
[ 44.914400][ C0] __might_resched (kernel/sched/core.c:8819) 
[ 44.914406][ C0] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 44.914410][ C0] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 44.914413][ C0] ? simple_recursive_removal (./include/linux/dcache.h:345 fs/libfs.c:610) 
[ 44.914417][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 44.914421][ C0] ? do_raw_spin_unlock (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/asm-generic/qspinlock.h:57 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141) 
[ 44.914427][ C0] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:616) 
[ 44.914430][ C0] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 44.914434][ C0] ? do_raw_spin_unlock (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/asm-generic/qspinlock.h:57 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141) 
[ 44.914439][ C0] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 44.914442][ C0] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 44.914448][ C0] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 44.914451][ C0] ? __sk_destruct (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/net_namespace.h:287 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 44.914456][ C0] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 44.914459][ C0] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 44.914462][ C0] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 44.914467][ C0] ? kthread (kernel/kthread.c:464) 
[ 44.914470][ C0] ? ret_from_fork (arch/x86/kernel/process.c:153) 
[ 44.914474][ C0] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 44.914478][ C0] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2417) 
[ 44.914482][ C0] ? __pfx_migrate_enable (kernel/sched/core.c:2392) 
[ 44.914487][ C0] __put_net (net/core/net_namespace.c:732) 
[ 44.914490][ C0] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 44.914494][ C0] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 44.914497][ C0] rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 44.914501][ C0] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 44.914505][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 44.914508][ C0] ? note_gp_changes (kernel/rcu/tree.c:1324 (discriminator 1)) 
[ 44.914510][ C0] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 44.914516][ C0] rcu_core (kernel/rcu/tree.c:2826) 
[ 44.914520][ C0] handle_softirqs (kernel/softirq.c:580) 
[ 44.914525][ C0] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 44.914528][ C0] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 44.914531][ C0] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 44.914535][ C0] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 44.914539][ C0] kthread (kernel/kthread.c:464) 
[ 44.914542][ C0] ? __pfx_kthread (kernel/kthread.c:413) 
[ 44.914544][ C0] ? ret_from_fork (arch/x86/kernel/process.c:152) 
[ 44.914547][ C0] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 44.914550][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 44.914553][ C0] ? __pfx_kthread (kernel/kthread.c:413) 
[ 44.914556][ C0] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 44.914559][ C0] ? __pfx_kthread (kernel/kthread.c:413) 


Finger prints:
mark_lock_irq:mark_lock:mark_usage:__lock_acquire:_raw_spin_lock
handle_softirqs:dump_stack_lvl:__might_resched:down_write:simple_recursive_removal