======================================
| [  802.311175][    C3] 1 lock held by ksoftirqd/3/32:
| [ 802.311352][ C3] #0: ffffffffb9d8b540 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [  802.311686][    C3]
| [  802.311686][    C3] stack backtrace:
[  802.311910][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  802.311913][    C3] Call Trace:
[  802.311915][    C3]  <TASK>
[ 802.311918][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 802.311925][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 802.311930][ C3] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 802.311934][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 802.311940][ C3] ? save_trace (kernel/locking/lockdep.c:595) 
[ 802.311946][ C3] mark_lock (kernel/locking/lockdep.c:4756) 
[ 802.311950][ C3] mark_usage (kernel/locking/lockdep.c:4645) 
[ 802.311952][ C3] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 802.311955][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 802.311959][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 802.311962][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 802.311965][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 802.311969][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 802.311971][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 802.311975][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 802.311978][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 802.311980][ C3] simple_pin_fs (fs/libfs.c:1067) 
[ 802.311984][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 802.311987][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 802.311993][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 802.311995][ C3] ? __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) 
[ 802.312000][ C3] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 802.312004][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 802.312007][ C3] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 802.312012][ C3] ? kthread (kernel/kthread.c:464) 
[ 802.312017][ C3] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 802.312019][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 802.312022][ C3] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 802.312026][ C3] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 802.312031][ C3] __put_net (net/core/net_namespace.c:732) 
[ 802.312038][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 802.312041][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 802.312045][ C3] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 802.312050][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 802.312055][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 802.312058][ C3] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 802.312060][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 802.312067][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 802.312072][ C3] handle_softirqs (kernel/softirq.c:580) 
[ 802.312076][ C3] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 802.312079][ C3] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 802.312081][ C3] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 802.312085][ C3] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 802.312089][ C3] kthread (kernel/kthread.c:464) 
[ 802.312093][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 802.312096][ C3] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 802.312098][ C3] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 802.312101][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 802.312104][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 802.312108][ C3] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 802.312110][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 802.312113][ C3] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [  802.322934][    C3] RCU nest depth: 0, expected: 0
| [  802.323101][    C3] INFO: lockdep is turned off.
| [  802.323268][    C3] Preemption disabled at:
| [ 802.323270][ C3] handle_softirqs (kernel/softirq.c:553) 
[  802.323614][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  802.323616][    C3] Call Trace:
[  802.323618][    C3]  <TASK>
[ 802.323620][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 802.323626][ C3] __might_resched (kernel/sched/core.c:8796) 
[ 802.323634][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 802.323637][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 802.323640][ C3] ? simple_recursive_removal (fs/libfs.c:614) 
[ 802.323645][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 802.323649][ C3] ? 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) 
[ 802.323654][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 802.323657][ C3] ? 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) 
[ 802.323660][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 802.323666][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 802.323670][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 802.323675][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 802.323677][ C3] ? __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) 
[ 802.323681][ C3] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 802.323686][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 802.323689][ C3] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 802.323692][ C3] ? kthread (kernel/kthread.c:464) 
[ 802.323696][ C3] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 802.323699][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 802.323704][ C3] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 802.323707][ C3] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 802.323712][ C3] __put_net (net/core/net_namespace.c:732) 
[ 802.323717][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 802.323720][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 802.323723][ C3] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 802.323729][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 802.323734][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 802.323736][ C3] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 802.323739][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 802.323744][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 802.323749][ C3] handle_softirqs (kernel/softirq.c:580) 
[ 802.323753][ C3] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 802.323757][ C3] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 802.323759][ C3] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 802.323763][ C3] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 802.323767][ C3] kthread (kernel/kthread.c:464) 
[ 802.323770][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 802.323773][ C3] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 802.323776][ C3] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 802.323779][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 802.323781][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 802.323785][ C3] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 802.323788][ C3] ? __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