======================================
| [   20.092073][    C2] 1 lock held by ksoftirqd/2/27:
| [ 20.092367][ C2] #0: ffffffff94f774c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   20.092877][    C2]
| [   20.092877][    C2] stack backtrace:
[   20.093249][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   20.093252][    C2] Call Trace:
[   20.093255][    C2]  <TASK>
[ 20.093261][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 20.093271][ C2] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 20.093280][ C2] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 20.093288][ C2] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 20.093296][ C2] ? save_trace (kernel/locking/lockdep.c:595) 
[ 20.093306][ C2] mark_lock (kernel/locking/lockdep.c:4756) 
[ 20.093312][ C2] mark_usage (kernel/locking/lockdep.c:4645) 
[ 20.093317][ C2] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 20.093323][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 20.093331][ C2] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 20.093336][ C2] ? simple_pin_fs (fs/libfs.c:1067) 
[ 20.093344][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 20.093351][ C2] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 20.093355][ C2] ? simple_pin_fs (fs/libfs.c:1067) 
[ 20.093363][ C2] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 20.093370][ C2] ? simple_pin_fs (fs/libfs.c:1067) 
[ 20.093375][ C2] simple_pin_fs (fs/libfs.c:1067) 
[ 20.093382][ C2] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 20.093389][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 20.093398][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 20.093403][ 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:2376) 
[ 20.093412][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 20.093417][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 20.093422][ C2] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 20.093429][ C2] ? kthread (kernel/kthread.c:464) 
[ 20.093433][ C2] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 20.093439][ C2] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 20.093445][ C2] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 20.093453][ C2] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 20.093462][ C2] __put_net (net/core/net_namespace.c:732) 
[ 20.093468][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 20.093475][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 20.093479][ C2] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 20.093488][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 20.093495][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 20.093500][ C2] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 20.093505][ C2] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 20.093513][ C2] rcu_core (kernel/rcu/tree.c:2834) 
[ 20.093520][ C2] handle_softirqs (kernel/softirq.c:579) 
[ 20.093528][ C2] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 20.093534][ C2] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 20.093539][ C2] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 20.093545][ C2] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 20.093552][ C2] kthread (kernel/kthread.c:464) 
[ 20.093558][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 20.093562][ C2] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 20.093566][ C2] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 20.093572][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 20.093578][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 20.093582][ C2] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 20.093586][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 20.093590][ C2] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   20.112778][    C2] RCU nest depth: 0, expected: 0
| [   20.113095][    C2] INFO: lockdep is turned off.
| [   20.113428][    C2] Preemption disabled at:
| [ 20.113432][ C2] handle_softirqs (kernel/softirq.c:553) 
[   20.114065][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   20.114069][    C2] Call Trace:
[   20.114072][    C2]  <TASK>
[ 20.114077][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 20.114087][ C2] __might_resched (kernel/sched/core.c:8796) 
[ 20.114097][ C2] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 20.114103][ C2] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 20.114108][ C2] ? simple_recursive_removal (fs/libfs.c:614) 
[ 20.114114][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 20.114120][ 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) 
[ 20.114129][ C2] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 20.114134][ 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) 
[ 20.114139][ C2] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 20.114150][ C2] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 20.114156][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 20.114164][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 20.114169][ 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:2376) 
[ 20.114177][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 20.114183][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 20.114188][ C2] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 20.114193][ C2] ? kthread (kernel/kthread.c:464) 
[ 20.114197][ C2] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 20.114203][ C2] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 20.114210][ C2] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 20.114216][ C2] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 20.114227][ C2] __put_net (net/core/net_namespace.c:732) 
[ 20.114233][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 20.114240][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 20.114244][ C2] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 20.114253][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 20.114259][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 20.114264][ C2] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 20.114269][ C2] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 20.114276][ C2] rcu_core (kernel/rcu/tree.c:2834) 
[ 20.114283][ C2] handle_softirqs (kernel/softirq.c:579) 
[ 20.114291][ C2] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 20.114298][ C2] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 20.114303][ C2] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 20.114309][ C2] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 20.114316][ C2] kthread (kernel/kthread.c:464) 
[ 20.114321][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 20.114325][ C2] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 20.114330][ C2] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 20.114336][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 20.114342][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 20.114359][ C2] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 20.114363][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 20.114368][ C2] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   24.225470][    C2] INFO: lockdep is turned off.
| [   24.225649][    C2] Preemption disabled at:
| [ 24.225651][ C2] handle_softirqs (kernel/softirq.c:553) 
| [   24.226020][    C2] Tainted: [W]=WARN
[   24.226022][    C2] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   24.226024][    C2] Call Trace:
[   24.226026][    C2]  <TASK>
[ 24.226028][ C2] dump_stack_lvl (lib/dump_stack.c:123) 
[ 24.226035][ C2] __might_resched (kernel/sched/core.c:8796) 
[ 24.226042][ C2] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 24.226047][ C2] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 24.226050][ C2] ? simple_recursive_removal (fs/libfs.c:614) 
[ 24.226055][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 24.226060][ 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) 
[ 24.226065][ C2] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 24.226068][ 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) 
[ 24.226071][ C2] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 24.226077][ C2] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 24.226081][ C2] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 24.226086][ C2] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 24.226089][ 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:2376) 
[ 24.226095][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 24.226098][ C2] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 24.226102][ C2] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 24.226106][ C2] ? kthread (kernel/kthread.c:464) 
[ 24.226109][ C2] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 24.226113][ C2] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 24.226118][ C2] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 24.226122][ C2] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 24.226125][ C2] ? bpf_sk_storage_free (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:871 net/core/bpf_sk_storage.c:61) 
[ 24.226129][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 24.226134][ C2] __put_net (net/core/net_namespace.c:732) 
[ 24.226138][ C2] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 24.226145][ C2] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 24.226148][ C2] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 24.226153][ C2] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 24.226156][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 24.226159][ C2] ? trace_irq_enable.constprop.0 (./include/trace/events/preemptirq.h:40) 
[ 24.226166][ C2] rcu_core (kernel/rcu/tree.c:2834) 
[ 24.226170][ C2] handle_softirqs (kernel/softirq.c:579) 
[ 24.226174][ C2] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 24.226178][ C2] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 24.226181][ C2] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 24.226185][ C2] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 24.226189][ C2] kthread (kernel/kthread.c:464) 
[ 24.226192][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 24.226194][ C2] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 24.226196][ C2] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 24.226200][ C2] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 24.226203][ C2] ? __pfx_kthread (kernel/kthread.c:413) 
[ 24.226206][ C2] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 24.226209][ 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