======================================
| [   13.621102][    C2] 1 lock held by ksoftirqd/2/27:
| [ 13.621272][ C2] #0: ffffffff96374480 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2562) 
| [   13.621572][    C2]
| [   13.621572][    C2] stack backtrace:
[   13.621784][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   13.621786][    C2] Call Trace:
[   13.621788][    C2]  <TASK>
[ 13.621791][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 13.621797][ C2] print_usage_bug.part.0 (kernel/locking/lockdep.c:4046) 
[ 13.621801][ C2] mark_lock_irq (kernel/locking/lockdep.c:4011 kernel/locking/lockdep.c:4057 kernel/locking/lockdep.c:4268) 
[ 13.621805][ C2] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 13.621809][ C2] ? save_trace (kernel/locking/lockdep.c:594) 
[ 13.621815][ C2] mark_lock (kernel/locking/lockdep.c:4754) 
[ 13.621818][ C2] mark_usage (kernel/locking/lockdep.c:4643) 
[ 13.621821][ C2] __lock_acquire (kernel/locking/lockdep.c:5189) 
[ 13.621826][ C2] lock_acquire.part.0 (kernel/locking/lockdep.c:472 kernel/locking/lockdep.c:5868) 
[ 13.621828][ C2] ? simple_pin_fs (fs/libfs.c:1066) 
[ 13.621832][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.621835][ C2] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5829) 
[ 13.621837][ C2] ? simple_pin_fs (fs/libfs.c:1066) 
[ 13.621840][ C2] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 13.621843][ C2] ? simple_pin_fs (fs/libfs.c:1066) 
[ 13.621846][ C2] simple_pin_fs (fs/libfs.c:1066) 
[ 13.621849][ C2] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 13.621852][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 13.621857][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 13.621861][ C2] ? __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:2333) 
[ 13.621866][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 13.621869][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 13.621872][ C2] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 13.621877][ C2] ? kthread (kernel/kthread.c:464) 
[ 13.621881][ C2] ? ret_from_fork (arch/x86/kernel/process.c:153) 
[ 13.621883][ C2] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 13.621886][ C2] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2417) 
[ 13.621890][ C2] ? __pfx_migrate_enable (kernel/sched/core.c:2392) 
[ 13.621895][ C2] __put_net (net/core/net_namespace.c:732) 
[ 13.621898][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2333) 
[ 13.621902][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 13.621905][ C2] rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 13.621910][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 13.621914][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.621916][ C2] ? note_gp_changes (kernel/rcu/tree.c:1324 (discriminator 1)) 
[ 13.621920][ C2] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 13.621925][ C2] rcu_core (kernel/rcu/tree.c:2826) 
[ 13.621929][ C2] handle_softirqs (kernel/softirq.c:579) 
[ 13.621933][ C2] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 13.621936][ C2] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 13.621939][ C2] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 13.621942][ C2] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 13.621946][ C2] kthread (kernel/kthread.c:464) 
[ 13.621950][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.621953][ C2] ? ret_from_fork (arch/x86/kernel/process.c:152) 
[ 13.621955][ C2] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 13.621958][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.621961][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.621964][ C2] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 13.621967][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.621970][ C2] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   13.631920][    C2] RCU nest depth: 0, expected: 0
| [   13.632089][    C2] INFO: lockdep is turned off.
| [   13.632254][    C2] Preemption disabled at:
| [ 13.632256][ C2] handle_softirqs (kernel/softirq.c:553) 
[   13.632595][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   13.632597][    C2] Call Trace:
[   13.632599][    C2]  <TASK>
[ 13.632601][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 13.632608][ C2] __might_resched (kernel/sched/core.c:8819) 
[ 13.632614][ C2] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 13.632617][ C2] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 13.632620][ C2] ? simple_recursive_removal (./include/linux/dcache.h:345 fs/libfs.c:610) 
[ 13.632624][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.632628][ C2] ? 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) 
[ 13.632633][ C2] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:616) 
[ 13.632636][ C2] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 13.632641][ C2] ? 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) 
[ 13.632645][ C2] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 13.632648][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 13.632654][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 13.632657][ C2] ? __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:2333) 
[ 13.632662][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 13.632666][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 13.632669][ C2] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 13.632674][ C2] ? kthread (kernel/kthread.c:464) 
[ 13.632677][ C2] ? ret_from_fork (arch/x86/kernel/process.c:153) 
[ 13.632681][ C2] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 13.632686][ C2] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2417) 
[ 13.632689][ C2] ? __pfx_migrate_enable (kernel/sched/core.c:2392) 
[ 13.632694][ C2] __put_net (net/core/net_namespace.c:732) 
[ 13.632698][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2333) 
[ 13.632701][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 13.632705][ C2] rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 13.632710][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 13.632714][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.632716][ C2] ? note_gp_changes (kernel/rcu/tree.c:1324 (discriminator 1)) 
[ 13.632720][ C2] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 13.632725][ C2] rcu_core (kernel/rcu/tree.c:2826) 
[ 13.632729][ C2] handle_softirqs (kernel/softirq.c:579) 
[ 13.632733][ C2] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 13.632736][ C2] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 13.632738][ C2] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 13.632742][ C2] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 13.632746][ C2] kthread (kernel/kthread.c:464) 
[ 13.632750][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.632753][ C2] ? ret_from_fork (arch/x86/kernel/process.c:152) 
[ 13.632755][ C2] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 13.632758][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.632761][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.632765][ C2] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 13.632767][ C2] ? __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