======================================
| [   12.974505][    C0] 1 lock held by ksoftirqd/0/14:
| [ 12.974679][ C0] #0: ffffffffab7774c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   12.974991][    C0]
| [   12.974991][    C0] stack backtrace:
[   12.975216][    C0] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.975218][    C0] Call Trace:
[   12.975220][    C0]  <TASK>
[ 12.975222][ C0] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.975227][ C0] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 12.975232][ C0] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 12.975237][ C0] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 12.975242][ C0] ? save_trace (kernel/locking/lockdep.c:595) 
[ 12.975246][ C0] mark_lock (kernel/locking/lockdep.c:4756) 
[ 12.975250][ C0] mark_usage (kernel/locking/lockdep.c:4645) 
[ 12.975253][ C0] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 12.975257][ C0] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 12.975261][ C0] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 12.975264][ C0] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.975268][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.975273][ C0] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 12.975275][ C0] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.975279][ C0] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 12.975282][ C0] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.975285][ C0] simple_pin_fs (fs/libfs.c:1067) 
[ 12.975288][ C0] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 12.975291][ C0] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.975296][ C0] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.975299][ 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:2376) 
[ 12.975304][ C0] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.975307][ C0] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.975310][ C0] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.975313][ C0] ? kthread (kernel/kthread.c:464) 
[ 12.975317][ C0] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.975320][ C0] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.975323][ C0] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 12.975327][ C0] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 12.975333][ C0] __put_net (net/core/net_namespace.c:732) 
[ 12.975337][ C0] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.975341][ C0] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.975344][ C0] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.975347][ C0] ? __schedule (kernel/sched/core.c:6658) 
[ 12.975353][ C0] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.975357][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.975360][ C0] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 12.975363][ C0] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.975368][ C0] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.975373][ C0] handle_softirqs (kernel/softirq.c:579) 
[ 12.975377][ C0] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 12.975381][ C0] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 12.975384][ C0] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.975387][ C0] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 12.975390][ C0] kthread (kernel/kthread.c:464) 
[ 12.975394][ C0] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.975396][ C0] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 12.975399][ C0] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.975403][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.975406][ C0] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.975409][ C0] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.975413][ C0] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.975415][ C0] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   12.985994][    C0] RCU nest depth: 0, expected: 0
| [   12.986152][    C0] INFO: lockdep is turned off.
| [   12.986319][    C0] Preemption disabled at:
| [ 12.986321][ C0] handle_softirqs (kernel/softirq.c:553) 
[   12.986646][    C0] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.986648][    C0] Call Trace:
[   12.986649][    C0]  <TASK>
[ 12.986651][ C0] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.986657][ C0] __might_resched (kernel/sched/core.c:8796) 
[ 12.986664][ C0] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 12.986668][ C0] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 12.986670][ C0] ? simple_recursive_removal (fs/libfs.c:614) 
[ 12.986675][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.986680][ 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) 
[ 12.986684][ C0] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 12.986687][ 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) 
[ 12.986690][ C0] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 12.986695][ C0] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 12.986698][ C0] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.986702][ C0] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.986705][ 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:2376) 
[ 12.986710][ C0] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.986714][ C0] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.986716][ C0] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.986719][ C0] ? kthread (kernel/kthread.c:464) 
[ 12.986722][ C0] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.986725][ C0] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.986729][ C0] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 12.986733][ C0] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 12.986738][ C0] __put_net (net/core/net_namespace.c:732) 
[ 12.986742][ C0] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.986746][ C0] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.986749][ C0] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.986752][ C0] ? __schedule (kernel/sched/core.c:6658) 
[ 12.986758][ C0] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.986761][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.986765][ C0] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 12.986768][ C0] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.986773][ C0] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.986777][ C0] handle_softirqs (kernel/softirq.c:579) 
[ 12.986782][ C0] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 12.986786][ C0] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 12.986789][ C0] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.986791][ C0] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 12.986795][ C0] kthread (kernel/kthread.c:464) 
[ 12.986798][ C0] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.986800][ C0] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 12.986803][ C0] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.986807][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.986810][ C0] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.986814][ C0] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.986817][ C0] ? __pfx_kthread (kernel/kthread.c:413) 


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