======================================
| xx__-> echo $?
| 0
| xx__-> [   53.396242][    C3] BUG: spinlock bad magic on CPU#3, ip/300
| [ 53.396624][ C3] lock: noop_qdisc+0x240/0x300, .magic: 00000000, .owner: ip/300, .owner_cpu: 3 
[   53.397397][    C3] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   53.397896][    C3] Call Trace:
[   53.398077][    C3]  <IRQ>
[ 53.398195][ C3] dump_stack_lvl (lib/dump_stack.c:122) 
[ 53.398444][ C3] do_raw_spin_unlock (kernel/locking/spinlock_debug.c:100 kernel/locking/spinlock_debug.c:141) 
[ 53.398685][ C3] _raw_spin_unlock (./arch/x86/include/asm/preempt.h:94 ./include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:186) 
[ 53.398931][ C3] net_tx_action (./include/net/sch_generic.h:226 ./include/net/sch_generic.h:217 ./include/net/pkt_sched.h:128 ./include/net/pkt_sched.h:124 net/core/dev.c:5323) 
[ 53.399170][ C3] handle_softirqs (kernel/softirq.c:554) 
[ 53.399395][ C3] ? dev_deactivate_many (./include/linux/bottom_half.h:33 ./include/linux/netdevice.h:4448 net/sched/sch_generic.c:571 net/sched/sch_generic.c:1363) 
[ 53.399634][ C3] do_softirq (kernel/softirq.c:455 kernel/softirq.c:442) 
[   53.399815][    C3]  </IRQ>
[   53.399934][    C3]  <TASK>
[ 53.400049][ C3] __local_bh_enable_ip (kernel/softirq.c:382) 
[ 53.400285][ C3] dev_deactivate_many (net/sched/sch_generic.c:1356) 
[ 53.400530][ C3] __dev_close_many (net/core/dev.c:1547) 
[ 53.400768][ C3] ? __pfx___dev_close_many (net/core/dev.c:1522) 
[ 53.400986][ C3] ? mark_held_locks (kernel/locking/lockdep.c:4273) 
[ 53.401207][ C3] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4299 kernel/locking/lockdep.c:4358) 
[ 53.401478][ C3] __dev_change_flags (./include/linux/list.h:111 ./include/linux/list.h:215 ./include/linux/list.h:229 net/core/dev.c:1571 net/core/dev.c:8836) 
[ 53.401700][ C3] ? __pfx___dev_change_flags (net/core/dev.c:8802) 
[ 53.401924][ C3] dev_change_flags (net/core/dev.c:8910) 
[ 53.402142][ C3] do_setlink (net/core/rtnetlink.c:2900) 
[ 53.402367][ C3] ? is_bpf_text_address (./include/linux/rcupdate.h:336 ./include/linux/rcupdate.h:869 ./kernel/bpf/core.c:769) 
[ 53.402593][ C3] ? __pfx_do_setlink (net/core/rtnetlink.c:2778) 
[ 53.402813][ C3] ? is_bpf_text_address (./kernel/bpf/core.c:772) 
[ 53.403027][ C3] ? kernel_text_address (kernel/extable.c:97 kernel/extable.c:94) 
[ 53.403253][ C3] ? __kernel_text_address (kernel/extable.c:79) 
[ 53.403473][ C3] ? unwind_get_return_address (arch/x86/kernel/unwind_orc.c:369 arch/x86/kernel/unwind_orc.c:364) 
[ 53.403693][ C3] ? __pfx_stack_trace_consume_entry (kernel/stacktrace.c:83) 
[ 53.403956][ C3] ? arch_stack_walk (arch/x86/kernel/stacktrace.c:26) 
[ 53.404207][ C3] ? stack_trace_save (kernel/stacktrace.c:123) 
[ 53.404453][ C3] ? __pfx_stack_trace_save (kernel/stacktrace.c:114) 
[ 53.404671][ C3] ? stack_depot_save_flags (lib/stackdepot.c:609) 
[ 53.404896][ C3] ? mark_lock (kernel/locking/lockdep.c:4655 (discriminator 3)) 
[ 53.405066][ C3] ? kasan_save_stack (mm/kasan/common.c:49) 
[ 53.405308][ C3] ? kasan_save_stack (mm/kasan/common.c:48) 
[ 53.405549][ C3] ? kasan_save_track (./arch/x86/include/asm/current.h:49 mm/kasan/common.c:60 mm/kasan/common.c:69) 
[ 53.405765][ C3] ? __kasan_kmalloc (mm/kasan/common.c:391) 
[ 53.405979][ C3] ? rtnl_newlink (./include/linux/slab.h:681 net/core/rtnetlink.c:3739) 
[ 53.406204][ C3] ? rtnetlink_rcv_msg (net/core/rtnetlink.c:6647) 
[ 53.406424][ C3] ? netlink_rcv_skb (net/netlink/af_netlink.c:2550) 
[ 53.406643][ C3] ? netlink_unicast (net/netlink/af_netlink.c:1331 net/netlink/af_netlink.c:1357) 
[ 53.406859][ C3] ? __nla_validate_parse (./include/net/netlink.h:1267 (discriminator 1) lib/nlattr.c:622 (discriminator 1)) 
[ 53.407077][ C3] ? ____sys_sendmsg (net/socket.c:730 net/socket.c:745 net/socket.c:2597) 
[ 53.407291][ C3] ? ___sys_sendmsg (net/socket.c:2653) 
[ 53.407512][ C3] __rtnl_newlink (net/core/rtnetlink.c:3696) 
[ 53.407734][ C3] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:227) 
[ 53.407954][ C3] ? __pfx___rtnl_newlink (net/core/rtnetlink.c:3557) 
[ 53.408187][ C3] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4299 kernel/locking/lockdep.c:4358) 
[ 53.408459][ C3] ? __create_object (mm/kmemleak.c:751) 
[ 53.408678][ C3] ? trace_kmalloc (./include/trace/events/kmem.h:54 (discriminator 52)) 
[ 53.408893][ C3] rtnl_newlink (net/core/rtnetlink.c:3744) 
[ 53.409063][ C3] rtnetlink_rcv_msg (net/core/rtnetlink.c:6647) 
[ 53.409302][ C3] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6541) 
[ 53.409540][ C3] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:227) 
[ 53.409776][ C3] ? mark_lock (kernel/locking/lockdep.c:4655 (discriminator 3)) 
[ 53.409953][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5142) 
[ 53.410191][ C3] netlink_rcv_skb (net/netlink/af_netlink.c:2550) 
[ 53.410434][ C3] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6541) 
[ 53.410673][ C3] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2527) 
[ 53.410894][ C3] ? netlink_deliver_tap (./include/linux/rcupdate.h:336 ./include/linux/rcupdate.h:869 net/netlink/af_netlink.c:340) 
[ 53.411108][ C3] ? netlink_deliver_tap (./include/linux/rcupdate.h:336 ./include/linux/rcupdate.h:869 ./include/net/netns/generic.h:48 net/netlink/af_netlink.c:333) 
[ 53.411338][ C3] netlink_unicast (net/netlink/af_netlink.c:1331 net/netlink/af_netlink.c:1357) 
[ 53.411574][ C3] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1342) 
[ 53.411811][ C3] ? find_held_lock (kernel/locking/lockdep.c:5249) 
[ 53.412046][ C3] netlink_sendmsg (net/netlink/af_netlink.c:1901) 
[ 53.412272][ C3] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1820) 
[ 53.412508][ C3] ? __might_fault (mm/memory.c:6388 mm/memory.c:6381) 
[ 53.412739][ C3] ? __import_iovec (lib/iov_iter.c:1263 lib/iov_iter.c:1279) 
[ 53.412981][ C3] ____sys_sendmsg (net/socket.c:730 net/socket.c:745 net/socket.c:2597) 
[ 53.413221][ C3] ? __pfx_____sys_sendmsg (net/socket.c:2543) 
[ 53.413450][ C3] ? __pfx_copy_msghdr_from_user (net/socket.c:2523) 
[ 53.413746][ C3] ? __pfx_validate_chain (kernel/locking/lockdep.c:3824) 
[ 53.413990][ C3] ___sys_sendmsg (net/socket.c:2653) 
[ 53.414239][ C3] ? __pfx____sys_sendmsg (net/socket.c:2640) 
[ 53.414473][ C3] ? find_held_lock (kernel/locking/lockdep.c:5249) 
[ 53.414704][ C3] ? __lock_release (kernel/locking/lockdep.c:5435) 
[ 53.414939][ C3] ? __debug_check_no_obj_freed (lib/debugobjects.c:1001) 
[ 53.415218][ C3] ? __pfx___lock_release (kernel/locking/lockdep.c:5411) 
[ 53.415450][ C3] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 53.415686][ C3] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4299 kernel/locking/lockdep.c:4358) 
[ 53.415980][ C3] ? __fget_light (./include/linux/atomic/atomic-arch-fallback.h:479 ./include/linux/atomic/atomic-instrumented.h:50 fs/file.c:1145) 
[ 53.416218][ C3] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2682) 
[ 53.416448][ C3] ? __pfx___sys_sendmsg (net/socket.c:2668) 
[ 53.416676][ C3] ? __virt_addr_valid (./arch/x86/include/asm/preempt.h:94 ./include/linux/rcupdate.h:953 ./include/linux/mmzone.h:2034 arch/x86/mm/physaddr.c:65) 
[ 53.416918][ C3] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 53.417146][ C3] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[   53.417449][    C3] RIP: 0033:0x7f0631d9f7b7
[ 53.417709][ C3] Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
All code
========
   0:	0a 00                	or     (%rax),%al
   2:	f7 d8                	neg    %eax
   4:	64 89 02             	mov    %eax,%fs:(%rdx)
   7:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   e:	eb b9                	jmp    0xffffffffffffffc9
  10:	0f 1f 00             	nopl   (%rax)
  13:	f3 0f 1e fa          	endbr64
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 10                	jne    0x33
  23:	b8 2e 00 00 00       	mov    $0x2e,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 51                	ja     0x83
  32:	c3                   	ret
  33:	48 83 ec 28          	sub    $0x28,%rsp
  37:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  3b:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 51                	ja     0x59
   8:	c3                   	ret
   9:	48 83 ec 28          	sub    $0x28,%rsp
   d:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  11:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)
[   53.418521][    C3] RSP: 002b:00007ffeac4f6dd8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   53.418867][    C3] RAX: ffffffffffffffda RBX: 00007ffeac4f7500 RCX: 00007f0631d9f7b7
[   53.419231][    C3] RDX: 0000000000000000 RSI: 00007ffeac4f6e40 RDI: 0000000000000005
[   53.419586][    C3] RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000078
[   53.419928][    C3] R10: 00007f0631c5def8 R11: 0000000000000246 R12: 0000000000000003


Finger prints:
do_raw_spin_unlock:_raw_spin_unlock:net_tx_action:handle_softirqs:do_softirq