panic: kernel diagnostic assertion "kn->kn_kq == kq" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_event.c", line 1867
Stopped at db_enter+0x25: addq $0x8,%rsp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
159072 40360 0 0x8001000 0x2000 0 syz-executor
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff830d70b0) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8308ab4a,ffffffff830ab13c,74b,ffffffff830306f9) at __assert+0x29
knote_remove(ffff8000371e8f60,fffffd806ec1e870,fffffd806ec1e8f8,0,1) at knote_remove+0x5aa knote_acquire sys/kern/kern_event.c:1771 [inline]
knote_remove(ffff8000371e8f60,fffffd806ec1e870,fffffd806ec1e8f8,0,1) at knote_remove+0x5aa sys/kern/kern_event.c:1879
kqueue_purge(ffff8000371e8f60,fffffd806ec1e870) at kqueue_purge+0x88
kqpoll_exit() at kqpoll_exit+0x4d sys/kern/kern_event.c:893
exit1(ffff8000371e8f60,0,0,3) at exit1+0x659 sys/kern/kern_exit.c:209
single_thread_check_locked(ffff8000371e8f60,0) at single_thread_check_locked+0x2d0 sys/kern/kern_sig.c:2078
userret(ffff8000371e8f60) at userret+0x9c sys/kern/kern_sig.c:2033
syscall(ffff8000371dda10) at syscall+0x9a7 mi_syscall_return sys/sys/syscall_mi.h:206 [inline]
syscall(ffff8000371dda10) at syscall+0x9a7 sys/arch/amd64/amd64/trap.c:598
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xb0749b34190, count: 4
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{1}>
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
*cpu1: kernel diagnostic assertion "kn->kn_kq == kq" failed: file "/syzkaller/managers/multicore/kernel/sys/kern/kern_event.c", line 1867
ddb{1}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff830d70b0) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8308ab4a,ffffffff830ab13c,74b,ffffffff830306f9) at __assert+0x29
knote_remove(ffff8000371e8f60,fffffd806ec1e870,fffffd806ec1e8f8,0,1) at knote_remove+0x5aa knote_acquire sys/kern/kern_event.c:1771 [inline]
knote_remove(ffff8000371e8f60,fffffd806ec1e870,fffffd806ec1e8f8,0,1) at knote_remove+0x5aa sys/kern/kern_event.c:1879
kqueue_purge(ffff8000371e8f60,fffffd806ec1e870) at kqueue_purge+0x88
kqpoll_exit() at kqpoll_exit+0x4d sys/kern/kern_event.c:893
exit1(ffff8000371e8f60,0,0,3) at exit1+0x659 sys/kern/kern_exit.c:209
single_thread_check_locked(ffff8000371e8f60,0) at single_thread_check_locked+0x2d0 sys/kern/kern_sig.c:2078
userret(ffff8000371e8f60) at userret+0x9c sys/kern/kern_sig.c:2033
syscall(ffff8000371dda10) at syscall+0x9a7 mi_syscall_return sys/sys/syscall_mi.h:206 [inline]
syscall(ffff8000371dda10) at syscall+0x9a7 sys/arch/amd64/amd64/trap.c:598
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xb0749b34190, count: -11
ddb{1}> show registers
rdi 0
rsi 0x1
rbp 0xffff8000371dd5e0
rbx 0xffff800029b7cd87
rdx 0xffff80000118ae80
rcx 0xffff8000371e8f60
rax 0xffff800029b7bff0
r8 0x101010101010101
r9 0x8080808080808080
r10 0xd61e1bc31bd61712
r11 0x9389dfad558f796b
r12 0xffff800029b7cb88
r13 0
r14 0
r15 0x1
rip 0xffffffff81ff41c5 db_enter+0x25
cs 0x8
rflags 0x246
rsp 0xffff8000371dd5d0
ss 0
db_enter+0x25: addq $0x8,%rsp
ddb{1}> show proc
PROC (syz-executor) tid=523044 pid=40360 tcnt=1 stat=onproc
flags process=8001000<SINGLEEXIT> proc=4082000<WEXIT,SUSPSINGLE,THREAD>
runpri=32, usrpri=50, slppri=32, nice=20
wchan=0x0, wmesg=, ps_single=0xffff8000371e9c08 scnt=0 ecnt=1
forw=0xffffffffffffffff, list=0xffff8000371e9c08,0xffff8000371e8040
process=0xffff800033f8b620 user=0xffff8000371d8000, vmspace=0xfffffd8060d7c6f8
estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=0, intr=0
ddb{1}> ps
PID TID PPID UID S FLAGS WAIT COMMAND
24260 85726 45082 0 2 0x8000000 syz-executor
24260 425523 45082 0 3 0xc000080 fsleep syz-executor
40360 159072 19672 0 7 0x8003000 syz-executor
54303 8075 91492 0 3 0x8000090 nanoslp syz-executor
54303 270611 91492 0 3 0xc000090 kqsel syz-executor
54303 9462 91492 0 3 0xc000090 fsleep syz-executor
42851 160481 37612 0 3 0x8000080 nanoslp syz-executor
42851 47992 37612 0 3 0xc000080 kqsel syz-executor
42851 251858 37612 0 3 0xc000080 fsleep syz-executor
72179 250442 60881 0 3 0x8000082 wait syz-executor
91492 66307 60881 0 3 0x8000082 nanoslp syz-executor
15602 470665 60881 0 3 0x8000002 biowait syz-executor
35460 37260 60881 0 3 0x8000082 nanoslp syz-executor
37612 87587 60881 0 3 0x8000082 nanoslp syz-executor
19672 214182 60881 0 3 0x8000082 nanoslp syz-executor
45082 491167 60881 0 3 0x8000082 nanoslp syz-executor
65945 490708 60881 0 3 0x8000082 wait syz-executor
75001 158903 0 0 3 0x14200 bored sosplice
60881 316795 70833 0 3 0x8000082 kqread syz-executor
70833 492946 61952 0 3 0x810008a sigsusp ksh
61952 299205 43029 0 3 0x18000098 kqread sshd-session
43029 500851 81285 0 3 0x18000092 kqread sshd-session
71628 282644 1 0 3 0x18100083 ttyin getty
81285 18582 1 0 3 0x18000088 kqread sshd
81267 362868 2360 74 3 0x19100092 bpf pflogd
2360 76975 1 0 3 0x18000080 sbwait pflogd
22868 143571 25838 73 2 0x19100010 syslogd
25838 244663 1 0 3 0x18100082 sbwait syslogd
55054 326302 1 0 3 0x18100080 kqread resolvd
54348 353499 11313 77 3 0x18100092 kqread dhcpleased
23396 181634 11313 77 3 0x18100092 kqread dhcpleased
11313 24192 1 0 3 0x18000080 kqread dhcpleased
19791 204515 0 0 3 0x14200 bored smr
28032 69432 0 0 3 0x14200 pgzero zerothread
83538 409341 0 0 3 0x14200 aiodoned aiodoned
33272 388935 0 0 3 0x14200 syncer update
64598 180542 0 0 3 0x14200 cleaner cleaner
5927 23834 0 0 3 0x14200 reaper reaper
28528 88969 0 0 3 0x14200 pgdaemon pagedaemon
93000 435518 0 0 3 0x14200 bored viomb
55525 491705 0 0 3 0x40014200 acpi0 acpi0
88205 350047 0 0 3 0x40014200 idle1
46280 324966 0 0 3 0x14200 bored softnet3
50865 392339 0 0 3 0x14200 bored softnet2
33722 194451 0 0 3 0x14200 bored softnet1
49052 85332 0 0 3 0x14200 bored softnet0
1610 473780 0 0 3 0x14200 bored systqmp
45145 344433 0 0 3 0x14200 bored systq
63957 368908 0 0 3 0x14200 tmoslp softclockmp
55736 486305 0 0 3 0x40014200 tmoslp softclock
43755 155518 0 0 3 0x40014200 idle0
1 433059 0 0 3 0x8000082 wait init
0 0 -1 0 3 0x10200 scheduler swapper
ddb{1}> show all locks
CPU 1:
exclusive mutex &kq->kq_lock r = 0 (0xfffffd806ec1e880)
#0 witness_lock+0x5b8 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5b8 sys/kern/subr_witness.c:1151
#1 mtx_enter_try+0x178
#2 mtx_enter+0x60 sys/kern/kern_lock.c:239
#3 knote_remove+0x295
#4 kqueue_purge+0x88
#5 kqpoll_exit+0x4d sys/kern/kern_event.c:893
#6 exit1+0x659 sys/kern/kern_exit.c:209
#7 single_thread_check_locked+0x2d0 sys/kern/kern_sig.c:2078
#8 userret+0x9c sys/kern/kern_sig.c:2033
#9 syscall+0x9a7 mi_syscall_return sys/sys/syscall_mi.h:206 [inline]
#9 syscall+0x9a7 sys/arch/amd64/amd64/trap.c:598
#10 Xsyscall+0x128
Process 15602 (syz-executor) thread 0xffff800029fd96d0 (470665)
exclusive rrwlock inode r = 0 (0xfffffd80650bc6f8)
#0 witness_lock+0x5b8 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5b8 sys/kern/subr_witness.c:1151
#1 rw_enter+0x41b sys/kern/kern_rwlock.c:309
#2 rrw_enter+0xbe sys/kern/kern_rwlock.c:464
#3 VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524
#4 ufs_ihashins+0x4f sys/ufs/ufs/ufs_ihash.c:120
#5 ffs_vget+0x187 sys/ufs/ffs/ffs_vfsops.c:1230
#6 ffs_inode_alloc+0x283 sys/ufs/ffs/ffs_alloc.c:393
#7 ufs_mkdir+0x113 sys/ufs/ufs/ufs_vnops.c:1112
#8 VOP_MKDIR+0x102 sys/kern/vfs_vops.c:394
#9 domkdirat+0x179 sys/kern/vfs_syscalls.c:3100
#10 syscall+0xaf8 mi_syscall sys/sys/syscall_mi.h:179 [inline]
#10 syscall+0xaf8 sys/arch/amd64/amd64/trap.c:577
#11 Xsyscall+0x128
exclusive rrwlock inode r = 0 (0xfffffd806deaa918)
#0 witness_lock+0x5b8 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5b8 sys/kern/subr_witness.c:1151
#1 rw_enter+0x41b sys/kern/kern_rwlock.c:309
#2 rrw_enter+0xbe sys/kern/kern_rwlock.c:464
#3 VOP_LOCK+0xa6 sys/kern/vfs_vops.c:524
#4 vn_lock+0xa4 sys/kern/vfs_vnops.c:564
#5 vfs_lookup+0x109 sys/kern/vfs_lookup.c:418
#6 namei+0x7aa sys/kern/vfs_lookup.c:250
#7 domkdirat+0x8b sys/kern/vfs_syscalls.c:3085
#8 syscall+0xaf8 mi_syscall sys/sys/syscall_mi.h:179 [inline]
#8 syscall+0xaf8 sys/arch/amd64/amd64/trap.c:577
#9 Xsyscall+0x128
ddb{1}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 10234 10237K 10801K 166960K 14171 0
pcb 17 20K 22K 166960K 458 0
rtable 172 13K 15K 166960K 1618 0
pf 36 10K 11K 166960K 157 0
ifaddr 40 15K 16K 166960K 219 0
ifgroup 65 2K 2K 166960K 249 0
sysctl 3 0K 0K 166960K 3 0
counters 66 36K 37K 166960K 168 0
ioctlops 0 0K 4K 166960K 1846 0
iov 0 0K 16K 166960K 279 0
mount 1 1K 1K 166960K 1 0
log 0 0K 0K 166960K 4 0
vnodes 1576 99K 99K 166960K 3830 0
UFS quota 1 32K 32K 166960K 1 0
UFS mount 5 36K 36K 166960K 5 0
shm 3 5K 9K 166960K 45 0
VM map 2 1K 1K 166960K 2 0
sem 12 0K 1K 166960K 261 0
dirhash 12 2K 2K 166960K 45 0
ACPI 1697 195K 286K 166960K 12548 0
file desc 17 61K 93K 166960K 1961 0
sigio 0 0K 0K 166960K 84 0
proc 70 91K 140K 166960K 1622 0
subproc 104 6K 7K 166960K 572 0
NFS srvsock 1 0K 0K 166960K 1 0
NFS daemon 1 16K 16K 166960K 1 0
ip_moptions 0 0K 0K 166960K 160 0
in_multi 77 5K 7K 166960K 523 0
ether_multi 1 0K 0K 166960K 8 0
mrt 1 0K 0K 166960K 6 0
ISOFS mount 1 32K 32K 166960K 1 0
MSDOSFS mount 1 16K 16K 166960K 1 0
ttys 229 1023K 1023K 166960K 229 0
exec 0 0K 1K 166960K 1109 0
pfkey data 0 0K 0K 166960K 1 0
tdb 3 0K 0K 166960K 3 0
VM swap 8 62K 64K 166960K 10 0
UVM amap 250 77K 96K 166960K 18323 0
UVM aobj 99 7K 7K 166960K 100 0
pinsyscall 42 84K 106K 166960K 3940 0
memdesc 1 4K 4K 166960K 1 0
crypto data 1 1K 1K 166960K 1 0
ip6_options 0 0K 0K 166960K 115 0
NDP 14 0K 1K 166960K 151 0
temp 76 6816K 6944K 166960K 85072 0
kqueue 15 24K 35K 166960K 253 0
SYN cache 2 16K 16K 166960K 2 0
ddb{1}> 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 120 413 0 410 7 6 1 4 0 8 0
rtentry 112 540 0 466 4 1 3 4 0 8 0
unpcb 144 1684 0 1666 14 10 4 6 0 8 2
syncache 336 5 0 5 1 1 0 1 0 8 0
tcpqe 32 1 0 1 1 1 0 1 0 8 0
tcpcb 808 643 0 638 16 11 5 8 0 8 3
arp 120 97 0 85 1 0 1 1 0 8 0
inpcb 336 2630 0 2619 30 23 7 13 0 8 5
nd6 136 141 0 122 1 0 1 1 0 8 0
pkpcb 40 7 0 7 3 2 1 1 0 8 1
kcovpl 48 44 0 36 1 0 1 1 0 8 0
ppxss 1168 11 0 11 4 4 0 1 0 8 0
pffrag 232 21 0 18 1 0 1 1 0 482 0
pffrnode 88 20 0 18 1 0 1 1 0 8 0
pffrent 40 161 0 158 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
pfstitem 24 168 0 115 1 0 1 1 0 8 0
pfstkey 128 168 0 115 3 0 3 3 0 8 0
pfstate 376 168 0 115 8 1 7 8 0 8 0
pfrule 1344 22 0 16 2 1 1 2 0 8 0
art_heap8 4096 1 0 0 1 0 1 1 0 8 0
art_heap4 256 2131 0 1779 32 4 28 29 0 8 0
art_table 32 2132 0 1779 4 0 4 4 0 8 0
art_node 16 537 0 473 1 0 1 1 0 8 0
sysvmsgpl 40 15 0 11 1 0 1 1 0 8 0
semupl 112 4 0 4 1 1 0 1 0 8 0
semapl 112 258 0 248 1 0 1 1 0 8 0
shmpl 112 97 0 1 3 0 3 3 0 8 0
dirhash 1024 39 0 22 3 0 3 3 0 8 0
dino2pl 256 4357 0 2783 99 0 99 99 0 8 0
ffsino 272 4357 0 2783 106 0 106 106 0 8 0
nchpl 144 6716 0 6118 64 41 23 64 0 8 0
uvmvnodes 80 6249 0 0 128 0 128 128 0 8 0
vnodes 216 6249 0 0 348 0 348 348 0 8 0
namei 1024 29606 0 29605 4 3 1 2 0 8 0
percpumem 16 98 0 51 1 0 1 1 0 8 0
vcpupl 3904 13 0 1 2 0 2 2 0 8 0
vmpool 696 20 0 8 2 0 2 2 0 8 0
kstatmem 264 128 0 102 3 0 3 3 0 8 0
scsiplug 72 2 0 2 2 1 1 1 0 8 1
scxspl 216 38694 0 38693 13 12 1 8 1 8 0
plimitpl 152 546 0 526 1 0 1 1 0 8 0
sigapl 424 2189 0 2139 10 4 6 7 0 8 0
futexpl 64 26112 0 26109 3 2 1 1 0 8 0
knotepl 120 588 0 0 16 0 16 16 0 8 0
knotepl: pool(0xffffffff835690f0:knotepl): page inconsistency: page 0x0; at page head addr 0xfffffd80645c4f90 (p 0xfffffd80645c4000)
kqueuepl 216 650 0 637 10 5 5 5 0 8 4
pipepl 320 532 0 505 3 0 3 3 0 8 0
fdescpl 496 2169 0 2138 5 0 5 5 0 8 0
filepl 152 18647 0 18348 35 19 16 19 0 8 3
lockfpl 104 1261 0 1228 5 4 1 3 0 8 0
lockfspl 48 459 0 456 2 1 1 2 0 8 0
sessionpl 144 57 0 48 1 0 1 1 0 8 0
pgrppl 48 119 0 102 1 0 1 1 0 8 0
ucredpl 104 3369 0 3355 1 0 1 1 0 8 0
zombiepl 144 2143 0 2139 2 1 1 1 0 8 0
processpl 1152 2189 0 2139 5 1 4 5 0 8 0
procpl 648 4550 0 4494 7 1 6 6 0 8 0
srpgc 96 18 0 18 2 1 1 1 0 8 1
sosppl 168 15 0 15 5 4 1 1 0 8 1
sockpl 664 4743 0 4711 38 29 9 17 0 8 5
mcl64k 65536 5 0 0 1 0 1 1 0 8 0
mcl12k 12288 2 0 0 1 0 1 1 0 8 0
mcl9k 9216 2 0 0 1 0 1 1 0 8 0
mcl8k 8192 4 0 0 1 0 1 1 0 8 0
mcl4k 4096 5 0 0 1 0 1 1 0 8 0
mcl2k 2048 233 0 0 30 1 29 30 0 8 0
mtagpl 96 46 0 0 2 0 2 2 0 8 0
mbufpl 256 547 0 0 30 0 30 30 0 8 0
bufpl 280 9575 0 2778 486 0 486 486 0 8 0
anonpl 24 345325 0 341750 62 12 50 51 0 185 17
amapchunkpl 152 60128 0 59604 37 6 31 32 0 158 8
amappl16 200 7341 0 7311 52 40 12 15 0 8 8
amappl15 192 8 0 8 2 2 0 1 0 8 0
amappl14 184 190 0 178 1 0 1 1 0 8 0
amappl13 176 6 0 6 2 2 0 1 0 8 0
amappl12 168 3403 0 3371 4 2 2 3 0 8 0
amappl11 160 57 0 43 1 0 1 1 0 8 0
amappl10 152 11 0 11 1 1 0 1 0 8 0
amappl9 144 216 0 216 2 2 0 1 0 8 0
amappl8 136 27 0 25 1 0 1 1 0 8 0
amappl7 128 182 0 170 1 0 1 1 0 8 0
amappl6 120 538 0 537 1 0 1 1 0 8 0
amappl5 112 295 0 283 1 0 1 1 0 8 0
amappl4 104 427 0 407 1 0 1 1 0 8 0
amappl3 96 11716 0 11593 4 0 4 4 0 8 0
amappl2 88 1100 0 1034 2 0 2 2 0 8 0
amappl1 80 15293 0 14710 16 3 13 14 0 8 0
amappl 88 17593 0 17410 5 0 5 5 0 92 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 99 0 1 2 0 2 2 0 8 0
uaddrrnd 24 2189 0 2146 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 2189 0 2146 1 0 1 1 0 8 0
vmmpekpl 168 18764 0 18713 5 1 4 4 0 8 0
vmmpepl 168 137327 0 135403 116 19 97 97 0 357 11
vmsppl 440 2188 0 2146 8 2 6 6 0 8 0
rwobjpl 56 45728 0 38415 105 1 104 104 0 8 0
pdppl 4096 4385 0 4304 167 83 84 89 0 8 3
pvpl 32 28756 0 0 233 1 232 232 0 265 0
pmappl 248 2188 0 2146 3 0 3 3 0 8 0
extentpl 40 56 0 38 1 0 1 1 0 8 0
phpool 112 529 0 132 12 0 12 12 0 8 0
ddb{1}> machine ddbcpu 0
Stopped at x86_ipi_db+0x27: addq $0x8,%rsp
x86_ipi_db(ffffffff8341fff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:393
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc
intr_handler(ffff8000371cb490,ffff80000006bc00) at intr_handler+0xe1 sys/arch/amd64/amd64/intr.c:553
Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f
__sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x1a kd_curproc sys/dev/kcov.c:585 [inline]
__sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x1a sys/dev/kcov.c:158
__mp_lock(ffffffff8356af18) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:113 [inline]
__mp_lock(ffffffff8356af18) at __mp_lock+0x1a3 sys/kern/kern_lock.c:144
__mp_acquire_count(ffffffff8356af18,1) at __mp_acquire_count+0x58
mi_switch() at mi_switch+0x658 sys/kern/sched_bsd.c:460
sleep_finish(0,1) at sleep_finish+0x229 sys/kern/kern_synch.c:416
msleep(ffff800033f8b778,ffff800033f8b720,20,ffffffff830a8709,0) at msleep+0x13b sys/kern/kern_synch.c:249
single_thread_set(ffff8000371e9c08,3) at single_thread_set+0x41e single_thread_wait sys/kern/kern_sig.c:2230 [inline]
single_thread_set(ffff8000371e9c08,3) at single_thread_set+0x41e sys/kern/kern_sig.c:2213
exit1(ffff8000371e9c08,0,0,1) at exit1+0xa4 sys/kern/kern_exit.c:133
end trace frame: 0xffff8000371cb850, count: 0
ddb{0}> trace
x86_ipi_db(ffffffff8341fff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:393
x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106
Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27
__sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc
intr_handler(ffff8000371cb490,ffff80000006bc00) at intr_handler+0xe1 sys/arch/amd64/amd64/intr.c:553
Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f
__sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x1a kd_curproc sys/dev/kcov.c:585 [inline]
__sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x1a sys/dev/kcov.c:158
__mp_lock(ffffffff8356af18) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:113 [inline]
__mp_lock(ffffffff8356af18) at __mp_lock+0x1a3 sys/kern/kern_lock.c:144
__mp_acquire_count(ffffffff8356af18,1) at __mp_acquire_count+0x58
mi_switch() at mi_switch+0x658 sys/kern/sched_bsd.c:460
sleep_finish(0,1) at sleep_finish+0x229 sys/kern/kern_synch.c:416
msleep(ffff800033f8b778,ffff800033f8b720,20,ffffffff830a8709,0) at msleep+0x13b sys/kern/kern_synch.c:249
single_thread_set(ffff8000371e9c08,3) at single_thread_set+0x41e single_thread_wait sys/kern/kern_sig.c:2230 [inline]
single_thread_set(ffff8000371e9c08,3) at single_thread_set+0x41e sys/kern/kern_sig.c:2213
exit1(ffff8000371e9c08,0,0,1) at exit1+0xa4 sys/kern/kern_exit.c:133
sys_exit(ffff8000371e9c08,ffff8000371cb930,ffff8000371cb880) at sys_exit+0x1a
syscall(ffff8000371cb930) at syscall+0xaf8 mi_syscall sys/sys/syscall_mi.h:179 [inline]
syscall(ffff8000371cb930) at syscall+0xaf8 sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x741a47a48df0, count: -17
ddb{0}> machine ddbcpu 1
Stopped at db_enter+0x25: addq $0x8,%rsp
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff830d70b0) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8308ab4a,ffffffff830ab13c,74b,ffffffff830306f9) at __assert+0x29
knote_remove(ffff8000371e8f60,fffffd806ec1e870,fffffd806ec1e8f8,0,1) at knote_remove+0x5aa knote_acquire sys/kern/kern_event.c:1771 [inline]
knote_remove(ffff8000371e8f60,fffffd806ec1e870,fffffd806ec1e8f8,0,1) at knote_remove+0x5aa sys/kern/kern_event.c:1879
kqueue_purge(ffff8000371e8f60,fffffd806ec1e870) at kqueue_purge+0x88
kqpoll_exit() at kqpoll_exit+0x4d sys/kern/kern_event.c:893
exit1(ffff8000371e8f60,0,0,3) at exit1+0x659 sys/kern/kern_exit.c:209
single_thread_check_locked(ffff8000371e8f60,0) at single_thread_check_locked+0x2d0 sys/kern/kern_sig.c:2078
userret(ffff8000371e8f60) at userret+0x9c sys/kern/kern_sig.c:2033
syscall(ffff8000371dda10) at syscall+0x9a7 mi_syscall_return sys/sys/syscall_mi.h:206 [inline]
syscall(ffff8000371dda10) at syscall+0x9a7 sys/arch/amd64/amd64/trap.c:598
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xb0749b34190, count: 4
ddb{1}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437
panic(ffffffff830d70b0) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff8308ab4a,ffffffff830ab13c,74b,ffffffff830306f9) at __assert+0x29
knote_remove(ffff8000371e8f60,fffffd806ec1e870,fffffd806ec1e8f8,0,1) at knote_remove+0x5aa knote_acquire sys/kern/kern_event.c:1771 [inline]
knote_remove(ffff8000371e8f60,fffffd806ec1e870,fffffd806ec1e8f8,0,1) at knote_remove+0x5aa sys/kern/kern_event.c:1879
kqueue_purge(ffff8000371e8f60,fffffd806ec1e870) at kqueue_purge+0x88
kqpoll_exit() at kqpoll_exit+0x4d sys/kern/kern_event.c:893
exit1(ffff8000371e8f60,0,0,3) at exit1+0x659 sys/kern/kern_exit.c:209
single_thread_check_locked(ffff8000371e8f60,0) at single_thread_check_locked+0x2d0 sys/kern/kern_sig.c:2078
userret(ffff8000371e8f60) at userret+0x9c sys/kern/kern_sig.c:2033
syscall(ffff8000371dda10) at syscall+0x9a7 mi_syscall_return sys/sys/syscall_mi.h:206 [inline]
syscall(ffff8000371dda10) at syscall+0x9a7 sys/arch/amd64/amd64/trap.c:598
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xb0749b34190, count: -11