======================================
| [ 12.891404][ C3] #1: ffff88800b599a50 (&sig->exec_update_lock){++++}-{4:4}, at: exec_mmap (fs/exec.c:904) 
| [ 12.891733][ C3] #2: ffffffff85b774c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   12.892063][    C3]
| [   12.892063][    C3] stack backtrace:
[   12.892304][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.892309][    C3] Call Trace:
[   12.892314][    C3]  <IRQ>
[ 12.892316][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.892322][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 12.892327][ C3] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 12.892331][ C3] ? rcu_read_lock_any_held (kernel/rcu/update.c:386 kernel/rcu/update.c:380) 
[ 12.892336][ C3] ? validate_chain (kernel/locking/lockdep.c:3804 kernel/locking/lockdep.c:3824 kernel/locking/lockdep.c:3879) 
[ 12.892339][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 12.892345][ C3] mark_lock (kernel/locking/lockdep.c:4756) 
[ 12.892349][ C3] mark_usage (kernel/locking/lockdep.c:4645) 
[ 12.892353][ C3] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 12.892356][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 12.892360][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 12.892364][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.892367][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.892371][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 12.892374][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.892378][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 12.892381][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.892384][ C3] simple_pin_fs (fs/libfs.c:1067) 
[ 12.892387][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 12.892390][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.892398][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.892400][ 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) 
[ 12.892410][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.892413][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.892415][ C3] ? __local_bh_enable_ip (kernel/softirq.c:407) 
[ 12.892418][ C3] ? flush_thread (./arch/x86/include/asm/cpufeature.h:101 ./arch/x86/include/asm/pkru.h:56 arch/x86/kernel/process.c:270 arch/x86/kernel/process.c:281) 
[ 12.892421][ C3] ? begin_new_exec (fs/exec.c:1232) 
[ 12.892424][ C3] ? load_elf_binary (fs/binfmt_elf.c:996) 
[ 12.892429][ C3] ? exec_binprm (fs/exec.c:1718 fs/exec.c:1750) 
[ 12.892432][ C3] ? bprm_execve (fs/exec.c:1802 fs/exec.c:1778) 
[ 12.892434][ C3] ? kernel_execve (fs/exec.c:1968) 
[ 12.892436][ C3] ? call_usermodehelper_exec_async (kernel/umh.c:113) 
[ 12.892440][ C3] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.892443][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.892448][ C3] __put_net (net/core/net_namespace.c:732) 
[ 12.892454][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.892458][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.892460][ C3] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.892465][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.892469][ C3] ? mark_held_locks (kernel/locking/lockdep.c:4328) 
[ 12.892472][ C3] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 12.892475][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.892481][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.892486][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 12.892490][ C3] ? fpu_flush_thread (./include/linux/bottom_half.h:33 ./arch/x86/include/asm/fpu/api.h:77 arch/x86/kernel/fpu/core.c:776 arch/x86/kernel/fpu/core.c:820) 
[ 12.892493][ C3] do_softirq (kernel/softirq.c:480 kernel/softirq.c:467) 
[   12.892497][    C3]  </IRQ>
[   12.892498][    C3]  <TASK>
[ 12.892499][ C3] __local_bh_enable_ip (kernel/softirq.c:407) 
[ 12.892503][ C3] flush_thread (./arch/x86/include/asm/cpufeature.h:101 ./arch/x86/include/asm/pkru.h:56 arch/x86/kernel/process.c:270 arch/x86/kernel/process.c:281) 
[ 12.892506][ C3] begin_new_exec (fs/exec.c:1232) 
[ 12.892511][ C3] load_elf_binary (fs/binfmt_elf.c:996) 
[ 12.892516][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 12.892521][ C3] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 12.892524][ C3] ? __pfx_load_elf_binary (fs/binfmt_elf.c:818) 
[ 12.892527][ C3] ? exec_binprm (fs/exec.c:1718 fs/exec.c:1750) 
[ 12.892531][ C3] exec_binprm (fs/exec.c:1718 fs/exec.c:1750) 
[ 12.892536][ C3] ? __pfx_exec_binprm (fs/exec.c:1734) 
[ 12.892538][ C3] ? bprm_execve (fs/exec.c:1792 fs/exec.c:1778) 
[ 12.892543][ C3] bprm_execve (fs/exec.c:1802 fs/exec.c:1778) 
[ 12.892546][ C3] kernel_execve (fs/exec.c:1968) 
[ 12.892550][ C3] call_usermodehelper_exec_async (kernel/umh.c:113) 
[ 12.892553][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.892556][ C3] ? __pfx_call_usermodehelper_exec_async (kernel/umh.c:64) 
[ 12.892559][ C3] ? __pfx_call_usermodehelper_exec_async (kernel/umh.c:64) 
[ 12.892562][ C3] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.892565][ C3] ? __pfx_call_usermodehelper_exec_async (kernel/umh.c:64) 
[ 12.892569][ C3] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   12.906664][    C3] RCU nest depth: 0, expected: 0
| [   12.906847][    C3] INFO: lockdep is turned off.
| [   12.907019][    C3] Preemption disabled at:
| [ 12.907021][ C3] fpu_flush_thread (arch/x86/kernel/fpu/context.h:33 arch/x86/kernel/fpu/core.c:760 arch/x86/kernel/fpu/core.c:820) 
[   12.907376][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.907378][    C3] Call Trace:
[   12.907379][    C3]  <IRQ>
[ 12.907381][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.907387][ C3] __might_resched (kernel/sched/core.c:8796) 
[ 12.907396][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 12.907399][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 12.907402][ C3] ? simple_recursive_removal (fs/libfs.c:614) 
[ 12.907406][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.907412][ 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) 
[ 12.907416][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 12.907419][ 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) 
[ 12.907422][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 12.907427][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 12.907430][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.907434][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.907436][ 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) 
[ 12.907440][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.907443][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.907446][ C3] ? __local_bh_enable_ip (kernel/softirq.c:407) 
[ 12.907450][ C3] ? flush_thread (./arch/x86/include/asm/cpufeature.h:101 ./arch/x86/include/asm/pkru.h:56 arch/x86/kernel/process.c:270 arch/x86/kernel/process.c:281) 
[ 12.907453][ C3] ? begin_new_exec (fs/exec.c:1232) 
[ 12.907456][ C3] ? load_elf_binary (fs/binfmt_elf.c:996) 
[ 12.907459][ C3] ? exec_binprm (fs/exec.c:1718 fs/exec.c:1750) 
[ 12.907461][ C3] ? bprm_execve (fs/exec.c:1802 fs/exec.c:1778) 
[ 12.907463][ C3] ? kernel_execve (fs/exec.c:1968) 
[ 12.907465][ C3] ? call_usermodehelper_exec_async (kernel/umh.c:113) 
[ 12.907469][ C3] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.907472][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.907477][ C3] __put_net (net/core/net_namespace.c:732) 
[ 12.907481][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.907485][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.907487][ C3] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.907492][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.907496][ C3] ? mark_held_locks (kernel/locking/lockdep.c:4328) 
[ 12.907500][ C3] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 12.907503][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.907508][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.907513][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 12.907517][ C3] ? fpu_flush_thread (./include/linux/bottom_half.h:33 ./arch/x86/include/asm/fpu/api.h:77 arch/x86/kernel/fpu/core.c:776 arch/x86/kernel/fpu/core.c:820) 
[ 12.907521][ C3] do_softirq (kernel/softirq.c:480 kernel/softirq.c:467) 
[   12.907524][    C3]  </IRQ>
[   12.907525][    C3]  <TASK>
[ 12.907526][ C3] __local_bh_enable_ip (kernel/softirq.c:407) 
[ 12.907530][ C3] flush_thread (./arch/x86/include/asm/cpufeature.h:101 ./arch/x86/include/asm/pkru.h:56 arch/x86/kernel/process.c:270 arch/x86/kernel/process.c:281) 
[ 12.907533][ C3] begin_new_exec (fs/exec.c:1232) 
[ 12.907538][ C3] load_elf_binary (fs/binfmt_elf.c:996) 
[ 12.907542][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 12.907548][ C3] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 12.907551][ C3] ? __pfx_load_elf_binary (fs/binfmt_elf.c:818) 
[ 12.907553][ C3] ? exec_binprm (fs/exec.c:1718 fs/exec.c:1750) 
[ 12.907558][ C3] exec_binprm (fs/exec.c:1718 fs/exec.c:1750) 
[ 12.907562][ C3] ? __pfx_exec_binprm (fs/exec.c:1734) 
[ 12.907565][ C3] ? bprm_execve (fs/exec.c:1792 fs/exec.c:1778) 
[ 12.907569][ C3] bprm_execve (fs/exec.c:1802 fs/exec.c:1778) 
[ 12.907573][ C3] kernel_execve (fs/exec.c:1968) 
[ 12.907576][ C3] call_usermodehelper_exec_async (kernel/umh.c:113) 
[ 12.907579][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.907583][ C3] ? __pfx_call_usermodehelper_exec_async (kernel/umh.c:64) 
[ 12.907585][ C3] ? __pfx_call_usermodehelper_exec_async (kernel/umh.c:64) 
[ 12.907589][ C3] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.907591][ C3] ? __pfx_call_usermodehelper_exec_async (kernel/umh.c:64) 


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