======================================
| xx__-> echo $?
| 0
| xx__-> [ 34.228250][ C3] BUG: spinlock bad magic on CPU#3, tc/303
| [ 34.228518][ C3] lock: noop_qdisc+0x240/0x300, .magic: 00000000, .owner: tc/303, .owner_cpu: 3
[ 34.229083][ C3] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 34.229428][ C3] Call Trace:
[ 34.229562][ C3]
[ 34.229649][ C3] dump_stack_lvl (lib/dump_stack.c:122)
[ 34.229816][ C3] do_raw_spin_unlock (kernel/locking/spinlock_debug.c:100 kernel/locking/spinlock_debug.c:141)
[ 34.229976][ C3] _raw_spin_unlock (./arch/x86/include/asm/preempt.h:94 ./include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:186)
[ 34.230131][ 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)
[ 34.230287][ C3] handle_softirqs (kernel/softirq.c:554)
[ 34.230448][ 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)
[ 34.230612][ C3] do_softirq (kernel/softirq.c:455 kernel/softirq.c:442)
[ 34.230739][ C3]
[ 34.230815][ C3]
[ 34.230889][ C3] __local_bh_enable_ip (kernel/softirq.c:382)
[ 34.231048][ C3] dev_deactivate_many (net/sched/sch_generic.c:1356)
[ 34.231205][ C3] ? __pfx___lock_release (kernel/locking/lockdep.c:5411)
[ 34.231355][ C3] dev_deactivate (./include/linux/list.h:111 ./include/linux/list.h:215 ./include/linux/list.h:229 net/sched/sch_generic.c:1398)
[ 34.231503][ C3] ? __pfx_dev_deactivate (net/sched/sch_generic.c:1393)
[ 34.231659][ C3] qdisc_graft (net/sched/sch_api.c:1137)
[ 34.231833][ C3] ? qdisc_create (net/sched/sch_api.c:1257)
[ 34.231985][ C3] ? __pfx_qdisc_graft (net/sched/sch_api.c:1105)
[ 34.232135][ C3] ? __pfx_qdisc_create (net/sched/sch_api.c:1257)
[ 34.232291][ C3] tc_modify_qdisc (net/sched/sch_api.c:1789)
[ 34.232441][ C3] ? trace_contention_end (./include/trace/events/lock.h:122 (discriminator 52))
[ 34.232591][ C3] ? __pfx_tc_modify_qdisc (net/sched/sch_api.c:1604)
[ 34.232746][ C3] ? __mutex_lock (./arch/x86/include/asm/preempt.h:94 kernel/locking/mutex.c:618 kernel/locking/mutex.c:752)
[ 34.232899][ C3] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52))
[ 34.233053][ C3] rtnetlink_rcv_msg (net/core/rtnetlink.c:6647)
[ 34.233209][ C3] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6541)
[ 34.233359][ 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)
[ 34.233506][ C3] ? mark_lock (kernel/locking/lockdep.c:4655 (discriminator 3))
[ 34.233616][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5142)
[ 34.233767][ C3] netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[ 34.233930][ C3] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6541)
[ 34.234080][ C3] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2527)
[ 34.234228][ C3] ? netlink_deliver_tap (./include/linux/rcupdate.h:336 ./include/linux/rcupdate.h:869 net/netlink/af_netlink.c:340)
[ 34.234375][ 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)
[ 34.234531][ C3] netlink_unicast (net/netlink/af_netlink.c:1331 net/netlink/af_netlink.c:1357)
[ 34.234682][ C3] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1342)
[ 34.234834][ C3] ? find_held_lock (kernel/locking/lockdep.c:5249)
[ 34.234989][ C3] netlink_sendmsg (net/netlink/af_netlink.c:1901)
[ 34.235146][ C3] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1820)
[ 34.235292][ C3] ? __might_fault (mm/memory.c:6388 mm/memory.c:6381)
[ 34.235443][ C3] ? __import_iovec (lib/iov_iter.c:1263 lib/iov_iter.c:1279)
[ 34.235605][ C3] ____sys_sendmsg (net/socket.c:730 net/socket.c:745 net/socket.c:2597)
[ 34.235769][ C3] ? __pfx_____sys_sendmsg (net/socket.c:2543)
[ 34.235926][ C3] ? __pfx_copy_msghdr_from_user (net/socket.c:2523)
[ 34.236121][ C3] ___sys_sendmsg (net/socket.c:2653)
[ 34.236275][ C3] ? __pfx____sys_sendmsg (net/socket.c:2640)
[ 34.236429][ C3] ? kfree (mm/slub.c:4583)
[ 34.236538][ C3] ? ___sys_recvmsg (net/socket.c:2848)
[ 34.236684][ C3] ? __pfx____sys_recvmsg (net/socket.c:2848)
[ 34.236835][ C3] ? reacquire_held_locks (kernel/locking/lockdep.c:5284)
[ 34.236983][ C3] ? do_user_addr_fault (./include/linux/rcupdate.h:326 ./include/linux/rcupdate.h:838 ./include/linux/mm.h:713 arch/x86/mm/fault.c:1340)
[ 34.237133][ C3] ? __fget_light (./include/linux/atomic/atomic-arch-fallback.h:479 ./include/linux/atomic/atomic-instrumented.h:50 fs/file.c:1145)
[ 34.237291][ C3] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2682)
[ 34.237438][ C3] ? __pfx___sys_sendmsg (net/socket.c:2668)
[ 34.237594][ C3] ? __pfx___up_read (kernel/locking/rwsem.c:1339)
[ 34.237747][ C3] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 34.237895][ C3] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 34.238084][ C3] RIP: 0033:0x7f44670157b7
[ 34.238246][ 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)
[ 34.238788][ C3] RSP: 002b:00007ffcd4db0f38 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 34.239039][ C3] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f44670157b7
[ 34.239269][ C3] RDX: 0000000000000000 RSI: 00007ffcd4db0fa0 RDI: 0000000000000005
[ 34.239532][ C3] RBP: 000000000047d6a0 R08: 0000000000000014 R09: 0000000000000000
[ 34.239768][ C3] R10: 00007f4466ece708 R11: 0000000000000246 R12: 00007ffcd4dc1260
Finger prints:
do_raw_spin_unlock:_raw_spin_unlock:net_tx_action:handle_softirqs:do_softirq