panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 944
Stopped at db_enter+0x25: addq $0x8,%rsp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8343fe55) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff833ea525,ffffffff833eea67,3b0,ffffffff833eeaaf) at __assert+0x29
refcnt_finalize(ffff8000fffef988,ffffffff8332f76d) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:945
pppx_if_destroy(205b9a,ffff8000fffef980) at pppx_if_destroy+0x3d sys/net/if_pppx.c:806
pppxclose(205b9a,1,2000,ffff8000ffff47d8) at pppxclose+0xa0 sys/net/if_pppx.c:553
spec_close(ffff80003a8d4500) at spec_close+0x412
VOP_CLOSE(fffffd806a0f17f0,1,fffffd807f7d2680,ffff8000ffff47d8) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156
vn_closefile(fffffd806bb46398,ffff8000ffff47d8) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd806bb46398,ffff8000ffff47d8) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd806bb46398,ffff8000ffff47d8) at fdrop+0x126 sys/kern/kern_descrip.c:1265
closef(fffffd806bb46398,ffff8000ffff47d8) at closef+0x192 sys/kern/kern_descrip.c:1249
fdfree(ffff8000ffff47d8) at fdfree+0x116 sys/kern/kern_descrip.c:1181
exit1(ffff8000ffff47d8,0,0,1) at exit1+0x58f sys/kern/kern_exit.c:216
sys_exit(ffff8000ffff47d8,ffff80003a8d4870,ffff80003a8d47c0) at sys_exit+0x1a
end trace frame: 0xffff80003a8d4860, count: 0
https://www.openbsd.org/ddb.html describes the minimum info required in bug
reports. Insufficient info makes it difficult to find and fix bugs.
ddb{0}>
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
*cpu0: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_synch.c", line 944
ddb{0}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8343fe55) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff833ea525,ffffffff833eea67,3b0,ffffffff833eeaaf) at __assert+0x29
refcnt_finalize(ffff8000fffef988,ffffffff8332f76d) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:945
pppx_if_destroy(205b9a,ffff8000fffef980) at pppx_if_destroy+0x3d sys/net/if_pppx.c:806
pppxclose(205b9a,1,2000,ffff8000ffff47d8) at pppxclose+0xa0 sys/net/if_pppx.c:553
spec_close(ffff80003a8d4500) at spec_close+0x412
VOP_CLOSE(fffffd806a0f17f0,1,fffffd807f7d2680,ffff8000ffff47d8) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156
vn_closefile(fffffd806bb46398,ffff8000ffff47d8) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd806bb46398,ffff8000ffff47d8) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd806bb46398,ffff8000ffff47d8) at fdrop+0x126 sys/kern/kern_descrip.c:1265
closef(fffffd806bb46398,ffff8000ffff47d8) at closef+0x192 sys/kern/kern_descrip.c:1249
fdfree(ffff8000ffff47d8) at fdfree+0x116 sys/kern/kern_descrip.c:1181
exit1(ffff8000ffff47d8,0,0,1) at exit1+0x58f sys/kern/kern_exit.c:216
sys_exit(ffff8000ffff47d8,ffff80003a8d4870,ffff80003a8d47c0) at sys_exit+0x1a
syscall(ffff80003a8d4870) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003a8d4870) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7e85aef2c250, count: -16
ddb{0}> show registers
rdi 0
rsi 0x1
rbp 0xffff80003a8d42d0
rbx 0xffffffff837e5dc7 cpu_info_full_primary+0x2dc7
rdx 0
rcx 0xffff8000ffff47d8
rax 0xffffffff837e4ff0 cpu_info_full_primary+0x1ff0
r8 0
r9 0x8080808080808080
r10 0x158e3a95a02894fe
r11 0xe216b6a623d71885
r12 0xffffffff837e5bc8 cpu_info_full_primary+0x2bc8
r13 0
r14 0
r15 0x1
rip 0xffffffff8136a795 db_enter+0x25
cs 0x8
rflags 0x246
rsp 0xffff80003a8d42c0
ss 0x10
db_enter+0x25: addq $0x8,%rsp
ddb{0}> show proc
PROC (syz-executor) tid=295408 pid=5928 tcnt=0 stat=onproc
flags process=1008<EXITING,SINGLEEXIT> proc=2000<WEXIT>
runpri=32, usrpri=86, slppri=32, nice=20
wchan=0x0, wmesg=, ps_single=0xffff8000ffff47d8 scnt=-1 ecnt=1
forw=0xffffffffffffffff, list=0xffff8000ffff4f88,0xffff8000ffff4d08
process=0xffff8000ffff04b8 user=0xffff80003a8cf000, vmspace=0xfffffd806be73900
estcpu=36, cpticks=4, pctcpu=0.0, user=0, sys=1, intr=0
ddb{0}> ps
PID TID PPID UID S FLAGS WAIT COMMAND
3925 146943 95856 0 2 0 syz-executor
3925 321346 95856 0 3 0x4000000 smrbar syz-executor
3925 168714 95856 0 3 0x4000080 fsleep syz-executor
3925 160356 95856 0 3 0x4000080 fsleep syz-executor
96205 88665 8455 0 2 0x1000000 syz-executor
96205 500111 8455 0 3 0x5000080 fsleep syz-executor
18900 53820 65020 0 2 0 syz-executor
18900 240256 65020 0 2 0x4000000 syz-executor
58675 356004 23501 0 2 0 syz-executor
58675 321394 23501 0 3 0x4000080 fsleep syz-executor
58675 206308 23501 0 3 0x4000080 fsleep syz-executor
19457 452754 0 0 3 0x14200 acct acct
7149 60852 0 0 3 0x14200 bored sosplice
23501 274718 21799 0 2 0x482 syz-executor
8455 200839 21799 0 3 0x82 nanoslp syz-executor
96135 140825 21799 0 2 0x482 syz-executor
46060 370792 21799 0 2 0x2 syz-executor
65020 470731 21799 0 2 0x482 syz-executor
89188 391699 21799 0 3 0x82 wait syz-executor
82615 309507 21799 0 2 0x482 syz-executor
95856 483090 21799 0 2 0x482 syz-executor
21799 511316 96502 0 3 0x82 kqread syz-executor
96502 200108 14024 0 3 0x10008a sigsusp ksh
14024 293132 84593 0 3 0x98 kqread sshd-session
84593 497668 23138 0 3 0x92 kqread sshd-session
74467 253779 1 0 3 0x100083 ttyin getty
23138 519768 1 0 3 0x88 kqread sshd
64796 274603 70180 74 3 0x1100092 bpf pflogd
70180 435821 1 0 3 0x80 sbwait pflogd
11346 94133 84418 73 3 0x1100090 kqread syslogd
84418 369616 1 0 3 0x100082 sbwait syslogd
42228 288267 1 0 3 0x100080 kqread resolvd
67696 499200 36133 77 3 0x100092 kqread dhcpleased
29944 351095 36133 77 3 0x100092 kqread dhcpleased
36133 216391 1 0 3 0x80 kqread dhcpleased
30290 407627 0 0 2 0x14200 smr
97510 305113 0 0 2 0x14200 zerothread
58978 112749 0 0 3 0x14200 aiodoned aiodoned
15340 253152 0 0 3 0x14200 syncer update
92924 440260 0 0 3 0x14200 cleaner cleaner
62133 381238 0 0 3 0x14200 reaper reaper
53797 447896 0 0 3 0x14200 pgdaemon pagedaemon
58422 265686 0 0 3 0x14200 bored viomb
98958 511865 0 0 3 0x40014200 acpi0 acpi0
1998 311119 0 0 7 0x40014200 idle1
38740 24427 0 0 3 0x14200 bored softnet3
50961 214434 0 0 3 0x14200 bored softnet2
23994 304890 0 0 3 0x14200 bored softnet1
35271 52393 0 0 3 0x14200 bored softnet0
27893 42285 0 0 3 0x14200 bored systqmp
97599 87624 0 0 3 0x14200 bored systq
22503 398148 0 0 3 0x14200 tmoslp softclockmp
88410 484603 0 0 2 0x40014200 softclock
89151 369469 0 0 3 0x40014200 idle0
1 309164 0 0 3 0x80082 wait init
0 0 -1 0 3 0x10010200 scheduler swapper
ddb{0}> show all locks
Process 46060 (syz-executor) thread 0xffff80002a36bc48 (370792)
exclusive rrwlock inode r = 0 (0xfffffd806bdd5ce8)
#0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5bb sys/kern/subr_witness.c:1155
#1 rw_do_enter_write+0x3ea sys/kern/kern_rwlock.c:316
#2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:616
#3 VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524
#4 vn_lock+0xa4 sys/kern/vfs_vnops.c:570
#5 vget+0x2bd sys/kern/vfs_subr.c:694
#6 ufs_ihashget+0x185 sys/ufs/ufs/ufs_ihash.c:98
#7 ffs_vget+0x8c sys/ufs/ffs/ffs_vfsops.c:1201
#8 ufs_lookup+0x19f8 sys/ufs/ufs/ufs_lookup.c:478
#9 VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85
#10 vfs_lookup+0x8fa sys/kern/vfs_lookup.c:566
#11 namei+0x7aa sys/kern/vfs_lookup.c:250
#12 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1866
#13 syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#13 syscall+0xb08 sys/arch/amd64/amd64/trap.c:577
#14 Xsyscall+0x128
exclusive rrwlock inode r = 0 (0xfffffd806c14e650)
#0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5bb sys/kern/subr_witness.c:1155
#1 rw_do_enter_write+0x3ea sys/kern/kern_rwlock.c:316
#2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:616
#3 VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524
#4 vn_lock+0xa4 sys/kern/vfs_vnops.c:570
#5 vfs_lookup+0x109 sys/kern/vfs_lookup.c:418
#6 namei+0x7aa sys/kern/vfs_lookup.c:250
#7 dounlinkat+0xc1 sys/kern/vfs_syscalls.c:1866
#8 syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#8 syscall+0xb08 sys/arch/amd64/amd64/trap.c:577
#9 Xsyscall+0x128
ddb{0}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 10237 11300K 11473K 166960K 12344 0
pcb 17 15K 16K 166960K 174 0
rtable 227 8K 9K 166960K 445 0
pf 40 18K 25K 166960K 94 0
ifaddr 44 7K 8K 166960K 73 0
ifgroup 60 2K 2K 166960K 106 0
sysctl 4 1K 1K 166960K 4 0
counters 68 36K 37K 166960K 132 0
ioctlops 0 0K 4K 166960K 1537 0
iov 0 0K 16K 166960K 25 0
mount 1 1K 1K 166960K 1 0
log 0 0K 0K 166960K 4 0
vnodes 1338 84K 85K 166960K 1732 0
UFS quota 1 32K 32K 166960K 1 0
UFS mount 5 36K 36K 166960K 5 0
shm 2 1K 5K 166960K 10 0
VM map 2 1K 1K 166960K 2 0
sem 12 0K 0K 166960K 28 0
dirhash 12 2K 2K 166960K 27 0
ACPI 1692 195K 286K 166960K 12470 0
file desc 17 61K 93K 166960K 652 0
sigio 0 0K 0K 166960K 43 0
proc 75 103K 140K 166960K 587 0
subproc 72 4K 4K 166960K 73 0
NFS srvsock 1 0K 0K 166960K 1 0
NFS daemon 1 16K 16K 166960K 1 0
ip_moptions 0 0K 0K 166960K 57 0
in_multi 95 7K 7K 166960K 125 0
ether_multi 1 0K 0K 166960K 2 0
mrt 1 0K 0K 166960K 2 0
ISOFS mount 1 32K 32K 166960K 1 0
MSDOSFS mount 1 16K 16K 166960K 1 0
ttys 187 837K 837K 166960K 187 0
exec 0 0K 1K 166960K 407 0
fusefs mount 1 32K 32K 166960K 1 0
tdb 3 0K 0K 166960K 3 0
VM swap 8 62K 64K 166960K 10 0
UVM amap 229 72K 77K 166960K 7579 0
UVM aobj 85 3K 3K 166960K 88 0
pinsyscall 42 84K 104K 166960K 1735 0
memdesc 1 4K 4K 166960K 1 0
crypto data 1 1K 1K 166960K 1 0
ip6_options 3 0K 0K 166960K 30 0
NDP 13 0K 2K 166960K 47 0
temp 53 8638K 8704K 166960K 30168 0
kqueue 15 24K 32K 166960K 129 0
SYN cache 2 16K 16K 166960K 2 0
ddb{0}> show all pools
Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
plcache 128 24 0 0 1 0 1 1 0 8 0
rtpcb 120 64 0 60 1 0 1 1 0 8 0
rtentry 112 140 0 40 4 0 4 4 0 8 0
unpcb 144 629 0 611 6 2 4 6 0 8 3
syncache 336 5 0 5 2 2 0 1 0 8 0
tcpqe 32 2 0 2 1 1 0 1 0 8 0
tcpcb 808 417 0 409 9 1 8 8 0 8 6
arp 120 24 0 7 1 0 1 1 0 8 0
inpcb 376 1017 0 1005 14 4 10 13 0 8 8
nd6 136 28 0 3 1 0 1 1 0 8 0
pkpcb 40 72 0 72 1 0 1 1 0 8 1
kcovpl 48 8 0 0 1 0 1 1 0 8 0
mppekey 1024 1 0 1 1 1 0 1 0 8 0
ppxss 1168 28 0 27 1 0 1 1 0 8 0
pppxif 1472 4 0 3 1 0 1 1 0 8 0
pfstscr 40 2 0 2 1 0 1 1 0 8 1
pffrag 232 3 0 0 1 0 1 1 0 482 0
pffrnode 88 3 0 0 1 0 1 1 0 8 0
pffrent 40 3 0 0 1 0 1 1 0 8 0
pfosfp 40 1428 0 1005 5 0 5 5 0 8 0
pfosfpen 112 1428 0 714 21 0 21 21 0 8 0
pftag 88 2 0 2 1 1 0 1 0 8 0
pfstitem 24 55 0 3 1 0 1 1 0 8 0
pfstkey 128 58 0 6 2 0 2 2 0 8 0
pfstate 376 56 0 5 6 0 6 6 0 8 0
pfrule 1344 23 0 18 2 1 1 2 0 8 0
art_heap8 4096 1 0 0 1 0 1 1 0 8 0
art_heap4 256 575 0 141 30 0 30 30 0 8 2
art_table 32 576 0 141 4 0 4 4 0 8 0
art_node 16 139 0 52 1 0 1 1 0 8 0
sysvmsgpl 40 41 0 39 1 0 1 1 0 8 0
semupl 112 2 0 2 2 2 0 1 0 8 0
semapl 112 25 0 15 1 0 1 1 0 8 0
shmpl 112 85 0 3 3 0 3 3 0 8 0
dirhash 1024 27 0 10 3 0 3 3 0 8 0
dino2pl 256 2535 0 1025 95 0 95 95 0 8 0
ffsino 280 2535 0 1025 109 0 109 109 0 8 0
nchpl 144 3460 0 1766 63 0 63 63 0 8 0
rtmask 32 5 0 5 1 0 1 1 0 8 1
uvmvnodes 80 2812 0 0 58 0 58 58 0 8 0
vnodes 216 2812 0 0 157 0 157 157 0 8 0
namei 1024 11600 0 11600 1 0 1 1 0 8 1
percpumem 16 80 0 32 1 0 1 1 0 8 0
kstatmem 264 58 0 32 3 0 3 3 0 8 1
scxspl 216 10933 0 10933 8 5 3 5 1 8 3
plimitpl 152 250 0 233 1 0 1 1 0 8 0
sigapl 424 955 0 904 7 1 6 7 0 8 0
futexpl 64 8546 0 8541 1 0 1 1 0 8 0
knotepl 120 510 0 0 16 0 16 16 0 8 0
kqueuepl 216 314 0 301 3 0 3 3 0 8 2
pipepl 328 154 0 127 3 0 3 3 0 8 0
fdescpl 504 933 0 902 5 0 5 5 0 8 0
filepl 152 5795 0 5562 16 2 14 16 0 8 3
lockfpl 104 156 0 151 1 0 1 1 0 8 0
lockfspl 48 60 0 56 1 0 1 1 0 8 0
sessionpl 144 23 0 14 1 0 1 1 0 8 0
pgrppl 48 37 0 20 1 0 1 1 0 8 0
ucredpl 104 832 0 819 1 0 1 1 0 8 0
zombiepl 144 907 0 904 1 0 1 1 0 8 0
processpl 1176 955 0 904 5 0 5 5 0 8 0
procpl 656 1844 0 1786 6 0 6 6 0 8 0
sosppl 168 8 0 8 1 0 1 1 0 8 1
sockpl 688 1882 0 1848 19 8 11 16 0 8 6
mcl64k 65536 2 0 0 1 0 1 1 0 8 0
mcl8k 8192 3 0 0 1 0 1 1 0 8 0
mcl4k 4096 132 0 0 17 0 17 17 0 8 0
mcl2k 2048 24 0 0 3 0 3 3 0 8 0
mtagpl 96 213 0 0 6 0 6 6 0 8 0
mbufpl 256 386 0 0 25 0 25 25 0 8 0
bufpl 280 3414 0 136 235 0 235 235 0 8 0
anonpl 24 140144 0 136706 32 4 28 28 0 184 0
amapchunkpl 152 23867 0 23364 24 0 24 24 0 158 1
amappl16 200 2433 0 2401 5 2 3 5 0 8 0
amappl15 192 7 0 7 1 1 0 1 0 8 0
amappl14 184 112 0 99 1 0 1 1 0 8 0
amappl13 176 5 0 5 2 2 0 1 0 8 0
amappl12 168 1573 0 1542 3 1 2 2 0 8 0
amappl11 160 51 0 37 1 0 1 1 0 8 0
amappl10 152 5 0 5 1 1 0 1 0 8 0
amappl9 144 260 0 259 1 0 1 1 0 8 0
amappl8 136 22 0 20 1 0 1 1 0 8 0
amappl7 128 106 0 94 1 0 1 1 0 8 0
amappl6 120 179 0 175 1 0 1 1 0 8 0
amappl5 112 121 0 111 1 0 1 1 0 8 0
amappl4 104 317 0 298 1 0 1 1 0 8 0
amappl3 96 4698 0 4581 4 0 4 4 0 8 0
amappl2 88 646 0 585 2 0 2 2 0 8 0
amappl1 80 9503 0 8929 15 1 14 14 0 8 0
amappl 88 7182 0 7009 5 0 5 5 0 92 0
dma65536 65536 1 0 1 1 1 0 1 0 8 0
dma8192 8192 2 0 2 1 1 0 1 0 8 0
dma4096 4096 1 0 1 1 1 0 1 0 8 0
dma1024 1024 1 0 0 1 0 1 1 0 8 0
dma256 256 6 0 6 1 1 0 1 0 8 0
dma128 128 253 0 253 1 1 0 1 0 8 0
dma64 64 6 0 6 1 1 0 1 0 8 0
dma32 32 7 0 7 1 1 0 1 0 8 0
dma16 16 18 0 17 1 0 1 1 0 8 0
aobjpl 72 87 0 3 2 0 2 2 0 8 0
uaddrrnd 24 933 0 902 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 933 0 902 1 0 1 1 0 8 0
vmmpekpl 168 9135 0 9099 3 0 3 3 0 8 0
vmmpepl 168 61586 0 59701 90 1 89 90 0 357 3
vmsppl 456 932 0 902 5 0 5 5 0 8 1
rwobjpl 64 21255 0 17417 63 0 63 63 0 8 0
pdppl 4096 1874 0 1804 100 28 72 86 0 8 2
pvpl 32 11525 0 0 93 0 93 93 0 265 0
pmappl 248 932 0 902 3 0 3 3 0 8 0
extentpl 40 55 0 38 1 0 1 1 0 8 0
phpool 112 300 0 36 8 0 8 8 0 8 0
ddb{0}> machine ddbcpu 0
Invalid cpu 0
ddb{0}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff8343fe55) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff833ea525,ffffffff833eea67,3b0,ffffffff833eeaaf) at __assert+0x29
refcnt_finalize(ffff8000fffef988,ffffffff8332f76d) at refcnt_finalize+0x1c8 sys/kern/kern_synch.c:945
pppx_if_destroy(205b9a,ffff8000fffef980) at pppx_if_destroy+0x3d sys/net/if_pppx.c:806
pppxclose(205b9a,1,2000,ffff8000ffff47d8) at pppxclose+0xa0 sys/net/if_pppx.c:553
spec_close(ffff80003a8d4500) at spec_close+0x412
VOP_CLOSE(fffffd806a0f17f0,1,fffffd807f7d2680,ffff8000ffff47d8) at VOP_CLOSE+0x133 sys/kern/vfs_vops.c:156
vn_closefile(fffffd806bb46398,ffff8000ffff47d8) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd806bb46398,ffff8000ffff47d8) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd806bb46398,ffff8000ffff47d8) at fdrop+0x126 sys/kern/kern_descrip.c:1265
closef(fffffd806bb46398,ffff8000ffff47d8) at closef+0x192 sys/kern/kern_descrip.c:1249
fdfree(ffff8000ffff47d8) at fdfree+0x116 sys/kern/kern_descrip.c:1181
exit1(ffff8000ffff47d8,0,0,1) at exit1+0x58f sys/kern/kern_exit.c:216
sys_exit(ffff8000ffff47d8,ffff80003a8d4870,ffff80003a8d47c0) at sys_exit+0x1a
syscall(ffff80003a8d4870) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003a8d4870) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7e85aef2c250, count: -16
ddb{0}> machine ddbcpu 1
Stopped at x86_ipi_db+0x27: addq $0x8,%rsp
x86_ipi_db(ffff800029aabff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
acpicpu_idle() at acpicpu_idle+0x41e sys/dev/acpi/acpicpu.c:1218
sched_idle(ffff800029aabff0) at sched_idle+0x558 sys/kern/kern_sched.c:182
end trace frame: 0x0, count: 10
ddb{1}> trace
x86_ipi_db(ffff800029aabff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
acpicpu_idle() at acpicpu_idle+0x41e sys/dev/acpi/acpicpu.c:1218
sched_idle(ffff800029aabff0) at sched_idle+0x558 sys/kern/kern_sched.c:182
end trace frame: 0x0, count: -5