====================================== | xx__-> echo $? | 0 | xx__-> [ 29.775258][ C0] BUG: spinlock bad magic on CPU#0, tc/286 | [ 29.775468][ C0] lock: noop_qdisc+0x240/0x300, .magic: 00000000, .owner: tc/286, .owner_cpu: 0 [ 29.775911][ C0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 29.776224][ C0] Call Trace: [ 29.776332][ C0] <IRQ> [ 29.776401][ C0] dump_stack_lvl (lib/dump_stack.c:122) [ 29.776539][ C0] do_raw_spin_unlock (kernel/locking/spinlock_debug.c:100 kernel/locking/spinlock_debug.c:141) [ 29.776672][ C0] _raw_spin_unlock (./arch/x86/include/asm/preempt.h:94 ./include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:186) [ 29.776824][ C0] 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) [ 29.776968][ C0] handle_softirqs (kernel/softirq.c:554) [ 29.777130][ C0] ? 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) [ 29.777276][ C0] do_softirq (kernel/softirq.c:455 kernel/softirq.c:442) [ 29.777378][ C0] </IRQ> [ 29.777447][ C0] <TASK> [ 29.777531][ C0] __local_bh_enable_ip (kernel/softirq.c:382) [ 29.777664][ C0] dev_deactivate_many (net/sched/sch_generic.c:1356) [ 29.777813][ C0] ? __pfx___lock_release (kernel/locking/lockdep.c:5411) [ 29.777947][ C0] dev_deactivate (./include/linux/list.h:111 ./include/linux/list.h:215 ./include/linux/list.h:229 net/sched/sch_generic.c:1398) [ 29.778103][ C0] ? __pfx_dev_deactivate (net/sched/sch_generic.c:1393) [ 29.778236][ C0] qdisc_graft (net/sched/sch_api.c:1137) [ 29.778370][ C0] ? qdisc_create (net/sched/sch_api.c:1257) [ 29.778507][ C0] ? __pfx_qdisc_graft (net/sched/sch_api.c:1105) [ 29.778653][ C0] ? __pfx_qdisc_create (net/sched/sch_api.c:1257) [ 29.778799][ C0] tc_modify_qdisc (net/sched/sch_api.c:1789) [ 29.778952][ C0] ? trace_contention_end (./include/trace/events/lock.h:122 (discriminator 52)) [ 29.779092][ C0] ? __pfx_tc_modify_qdisc (net/sched/sch_api.c:1604) [ 29.779240][ C0] ? __mutex_lock (./arch/x86/include/asm/preempt.h:94 kernel/locking/mutex.c:618 kernel/locking/mutex.c:752) [ 29.779376][ C0] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) [ 29.779524][ C0] rtnetlink_rcv_msg (net/core/rtnetlink.c:6647) [ 29.779673][ C0] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6541) [ 29.779817][ C0] ? 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) [ 29.779961][ C0] ? mark_lock (kernel/locking/lockdep.c:4655 (discriminator 3)) [ 29.780075][ C0] ? __lock_acquire (kernel/locking/lockdep.c:5142) [ 29.780207][ C0] netlink_rcv_skb (net/netlink/af_netlink.c:2550) [ 29.780363][ C0] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6541) [ 29.780495][ C0] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2527) [ 29.780632][ C0] ? netlink_deliver_tap (./include/linux/rcupdate.h:336 ./include/linux/rcupdate.h:869 net/netlink/af_netlink.c:340) [ 29.780788][ C0] ? 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) [ 29.780926][ C0] netlink_unicast (net/netlink/af_netlink.c:1331 net/netlink/af_netlink.c:1357) [ 29.781079][ C0] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1342) [ 29.781209][ C0] ? find_held_lock (kernel/locking/lockdep.c:5249) [ 29.781369][ C0] netlink_sendmsg (net/netlink/af_netlink.c:1901) [ 29.781507][ C0] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1820) [ 29.781658][ C0] ? __might_fault (mm/memory.c:6388 mm/memory.c:6381) [ 29.781798][ C0] ? __import_iovec (lib/iov_iter.c:1263 lib/iov_iter.c:1279) [ 29.781934][ C0] ____sys_sendmsg (net/socket.c:730 net/socket.c:745 net/socket.c:2597) [ 29.782088][ C0] ? __pfx_____sys_sendmsg (net/socket.c:2543) [ 29.782223][ C0] ? __pfx_copy_msghdr_from_user (net/socket.c:2523) [ 29.782417][ C0] ___sys_sendmsg (net/socket.c:2653) [ 29.782572][ C0] ? __pfx____sys_sendmsg (net/socket.c:2640) [ 29.782705][ C0] ? kfree (mm/slub.c:4583) [ 29.782817][ C0] ? ___sys_recvmsg (net/socket.c:2848) [ 29.782948][ C0] ? __pfx____sys_recvmsg (net/socket.c:2848) [ 29.783100][ C0] ? reacquire_held_locks (kernel/locking/lockdep.c:5284) [ 29.783233][ C0] ? 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) [ 29.783394][ C0] ? __fget_light (./include/linux/atomic/atomic-arch-fallback.h:479 ./include/linux/atomic/atomic-instrumented.h:50 fs/file.c:1145) [ 29.783539][ C0] __sys_sendmsg (./include/linux/file.h:34 net/socket.c:2682) [ 29.783684][ C0] ? __pfx___sys_sendmsg (net/socket.c:2668) [ 29.783827][ C0] ? __pfx___up_read (kernel/locking/rwsem.c:1339) [ 29.783978][ C0] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) [ 29.784125][ C0] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) [ 29.784319][ C0] RIP: 0033:0x7f0a098697b7 [ 29.784461][ C0] 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) [ 29.784956][ C0] RSP: 002b:00007fff80314ab8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 29.785178][ C0] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f0a098697b7 [ 29.785375][ C0] RDX: 0000000000000000 RSI: 00007fff80314b20 RDI: 0000000000000005 [ 29.785570][ C0] RBP: 000000000047d6a0 R08: 0000000000000014 R09: 0000000000000000 [ 29.785768][ C0] R10: 00007f0a09722708 R11: 0000000000000246 R12: 00007fff80324de0 Finger prints: do_raw_spin_unlock:_raw_spin_unlock:net_tx_action:handle_softirqs:do_softirq