======================================
| [   12.835848][    C1] 1 lock held by ksoftirqd/1/22:
| [ 12.836022][ C1] #0: ffffffffbb9774c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   12.836330][    C1]
| [   12.836330][    C1] stack backtrace:
[   12.836546][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.836548][    C1] Call Trace:
[   12.836550][    C1]  <TASK>
[ 12.836552][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.836558][ C1] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 12.836563][ C1] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 12.836567][ C1] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 12.836572][ C1] ? save_trace (kernel/locking/lockdep.c:595) 
[ 12.836576][ C1] mark_lock (kernel/locking/lockdep.c:4756) 
[ 12.836580][ C1] mark_usage (kernel/locking/lockdep.c:4645) 
[ 12.836584][ C1] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 12.836587][ C1] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 12.836591][ C1] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 12.836595][ C1] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.836598][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.836603][ C1] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 12.836606][ C1] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.836609][ C1] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 12.836613][ C1] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.836615][ C1] simple_pin_fs (fs/libfs.c:1067) 
[ 12.836618][ C1] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 12.836621][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:411 lib/ref_tracker.c:195) 
[ 12.836626][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 12.836629][ C1] ? __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) 
[ 12.836634][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.836637][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 12.836640][ C1] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.836643][ C1] ? kthread (kernel/kthread.c:464) 
[ 12.836646][ C1] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.836650][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.836652][ C1] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 12.836656][ C1] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 12.836662][ C1] __put_net (net/core/net_namespace.c:732) 
[ 12.836665][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.836670][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.836672][ C1] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.836677][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.836681][ C1] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.836684][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.836687][ C1] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 12.836692][ C1] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.836697][ C1] handle_softirqs (kernel/softirq.c:579) 
[ 12.836701][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 12.836705][ C1] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 12.836708][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.836711][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 12.836714][ C1] kthread (kernel/kthread.c:464) 
[ 12.836717][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.836720][ C1] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 12.836722][ C1] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.836726][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.836729][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.836733][ C1] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.836736][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.836738][ C1] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   12.848157][    C1] RCU nest depth: 0, expected: 0
| [   12.848313][    C1] INFO: lockdep is turned off.
| [   12.848476][    C1] Preemption disabled at:
| [ 12.848478][ C1] handle_softirqs (kernel/softirq.c:553) 
[   12.848804][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.848806][    C1] Call Trace:
[   12.848807][    C1]  <TASK>
[ 12.848809][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.848815][ C1] __might_resched (kernel/sched/core.c:8796) 
[ 12.848822][ C1] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 12.848826][ C1] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 12.848829][ C1] ? simple_recursive_removal (fs/libfs.c:614) 
[ 12.848833][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.848838][ C1] ? 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) 
[ 12.848842][ C1] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 12.848845][ C1] ? 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) 
[ 12.848847][ C1] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 12.848853][ C1] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 12.848856][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:411 lib/ref_tracker.c:195) 
[ 12.848860][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 12.848862][ C1] ? __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) 
[ 12.848867][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.848870][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 12.848873][ C1] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.848875][ C1] ? kthread (kernel/kthread.c:464) 
[ 12.848878][ C1] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.848882][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.848885][ C1] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 12.848889][ C1] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 12.848894][ C1] __put_net (net/core/net_namespace.c:732) 
[ 12.848898][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.848902][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.848905][ C1] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.848910][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.848913][ C1] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.848918][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.848921][ C1] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 12.848926][ C1] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.848930][ C1] handle_softirqs (kernel/softirq.c:579) 
[ 12.848935][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 12.848939][ C1] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 12.848942][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.848945][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 12.848948][ C1] kthread (kernel/kthread.c:464) 
[ 12.848951][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.848954][ C1] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 12.848957][ C1] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.848961][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.848964][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.848968][ C1] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.848971][ C1] ? __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