syzbot
protection_fault: amap_lookups
Status:
upstream: reported on 2026/07/15 10:53
Reported-by: syzbot+f5100bce607e33322166@syzkaller.appspotmail.com
First crash: 9d20h, last: 2d04h
Sample crash report:
kernel: protection fault trap, code=0
Stopped at amap_lookups+0x1e0: movl 0x10(%r15),%r14d
ddb{0}>
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
the kernel did not panic
ddb{0}> show kasan
No such command
ddb{0}> trace
amap_lookups(fffff4806cb43c68,6000,ffff80003c1e5d70,8) at amap_lookups+0x1e0 amap_chunk_get sys/uvm/uvm_amap.c:118 [inline]
amap_lookups(fffff4806cb43c68,6000,ffff80003c1e5d70,8) at amap_lookups+0x1e0 sys/uvm/uvm_amap.c:1168
uvm_fault_check(ffff80003c1e5e70,ffff80003c1e5ea8,ffff80003c1e5ee0,0) at uvm_fault_check+0x8d2 sys/uvm/uvm_fault.c:840
uvm_fault(fffff4806d1469b8,53884bda000,0,1) at uvm_fault+0x106 sys/uvm/uvm_fault.c:627
upageflttrap(ffff80003c1e6010,53884bdab50) at upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192
usertrap(ffff80003c1e6010) at usertrap+0x430 sys/arch/amd64/amd64/trap.c:640
recall_trap() at recall_trap+0x8
end of kernel
end trace frame: 0x7e4d0b786240, count: -6
ddb{0}> show registers
rdi 0x11
rsi 0x20
rbp 0xffff80003c1e5cc0
rbx 0
rdx 0
rcx 0
rax 0xffff800000c43f50
r8 0xffffffff82b304c0 uvm_map_inentry_sp
r9 0
r10 0
r11 0x5f09af781b06a73
r12 0xe
r13 0
r14 0x20
r15 0x1495d00004000
rip 0xffffffff832373a0 amap_lookups+0x1e0
cs 0x8
rflags 0x10206 __ALIGN_SIZE+0xf206
rsp 0xffff80003c1e5c30
ss 0
amap_lookups+0x1e0: movl 0x10(%r15),%r14d
ddb{0}> show proc
PROC (syz-executor) tid=247853 pid=23884 tcnt=1 stat=onproc
flags process=10<SUGID> proc=0
runpri=50, usrpri=50, slppri=17, nice=20
wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
forw=0xffffffffffffffff, list=0xffff800045fe2028,0xffffffff83a76c28
process=0xffff800045fe5d00 user=0xffff80003c1e1000, vmspace=0xfffff4806d1469b8
estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0
ddb{0}> ps
PID TID PPID UID S PRLAGS PFLAGS WAIT COMMAND
*23884 247853 69211 32767 7 0x10 0 syz-executor
40217 413675 70000 32767 7 0x10 0 syz-executor
40217 388660 70000 32767 2 0x10 0x4000000 syz-executor
79805 465227 19590 32767 2 0x10 0 syz-executor
79805 383666 19590 32767 3 0x10 0x4000080 fsleep syz-executor
73414 136266 99445 32767 3 0x10 0x80 nanoslp syz-executor
73414 355345 99445 32767 3 0x10 0x4000080 fsleep syz-executor
73414 207764 99445 32767 3 0x10 0x4000080 sbwait syz-executor
73414 447100 99445 32767 3 0x10 0x4000080 fsleep syz-executor
30655 28263 26365 32767 3 0x10 0x80 nanoslp syz-executor
30655 45323 26365 32767 3 0x10 0x4000080 piperd syz-executor
30655 53779 26365 32767 3 0x10 0x4000080 fsleep syz-executor
82535 445623 14243 32767 2 0x10 0 syz-executor
82535 401126 14243 32767 3 0x10 0x4000080 fsleep syz-executor
82535 197467 14243 32767 3 0x10 0x4000080 fsleep syz-executor
68821 113236 52924 32767 2 0x10 0 syz-executor
68821 372242 52924 32767 3 0x10 0x4000000 inode syz-executor
68821 378288 52924 32767 2 0x10 0x4000000 syz-executor
70000 119683 53825 32767 3 0x10 0x80 nanoslp syz-executor
26365 390887 62900 32767 3 0x10 0x80 nanoslp syz-executor
99445 109888 40632 32767 3 0x10 0x80 nanoslp syz-executor
52924 496344 75724 32767 3 0x10 0x80 nanoslp syz-executor
19590 149005 47976 32767 3 0x10 0x80 nanoslp syz-executor
69211 465136 31354 32767 3 0x10 0x80 nanoslp syz-executor
14243 285701 69988 32767 3 0x10 0x80 nanoslp syz-executor
40632 356119 18030 0 3 0x2 0x80 wait syz-executor
75724 31693 18030 0 3 0x2 0x80 wait syz-executor
47976 146091 18030 0 3 0x2 0x80 wait syz-executor
62900 504174 18030 0 3 0x2 0x80 wait syz-executor
31354 338696 18030 0 3 0x2 0x80 wait syz-executor
69988 173657 18030 0 3 0x2 0x80 wait syz-executor
53825 239141 18030 0 3 0x2 0x80 wait syz-executor
18030 264580 59786 0 3 0x2 0x80 nanoslp syz-executor
59786 259513 80593 0 3 0x100002 0x88 sigsusp ksh
80593 240550 71897 0 3 0x10 0x88 kqread sshd-session
71897 233585 28267 0 3 0x12 0x80 kqread sshd-session
53692 324388 1 0 3 0x100003 0x80 ttyin getty
28267 425646 1 0 3 0 0x88 kqread sshd
28226 232009 16221 73 3 0x1100010 0x80 kqread syslogd
16221 515007 1 0 3 0x100002 0x80 sbwait syslogd
1242 252031 1 0 3 0x100000 0x80 kqread resolvd
51729 296228 62474 77 3 0x100012 0x80 kqread dhcpleased
87643 434608 62474 77 3 0x100012 0x80 kqread dhcpleased
62474 218733 1 0 3 0 0x80 kqread dhcpleased
88628 424852 0 0 3 0x14000 0x200 bored smr
10708 190873 0 0 2 0x14000 0x200 zerothread
32446 371360 0 0 3 0x14000 0x200 aiodoned aiodoned
37796 179105 0 0 3 0x14000 0x200 syncer update
518 151134 0 0 3 0x14000 0x200 cleaner cleaner
26076 378290 0 0 3 0x14000 0x200 reaper reaper
71684 427640 0 0 3 0x14000 0x200 pgdaemon pagedaemon
6995 159595 0 0 3 0x14000 0x200 bored viomb
59737 503501 0 0 3 0x14000 0x40000200 acpi0 acpi0
51215 374101 0 0 3 0x14000 0x40000200 idle1
93182 240316 0 0 3 0x14000 0x200 bored softnet1
52901 513074 0 0 3 0x14000 0x200 bored softnet0
85962 80205 0 0 3 0x14000 0x200 bored systqmp
36743 457108 0 0 3 0x14000 0x200 bored systq
43175 491848 0 0 3 0x14000 0x200 tmoslp softclockmp
76354 32499 0 0 3 0x14000 0x40000200 tmoslp softclock
79705 100732 0 0 3 0x14000 0x40000200 idle0
1 317670 0 0 3 0x2 0x80 wait init
0 0 -1 0 3 0x10000 0x200 scheduler swapper
ddb{0}> show all locks
Process 23884 (syz-executor) thread 0xffff800045fe2558 (247853)
shared rwlock amaplk r = 0 (0xfffff4806e350a30)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 rw_do_enter_read+0x3e8 sys/kern/kern_rwlock.c:413
#2 uvm_fault_check+0x8a9 sys/uvm/uvm_fault.c:834
#3 uvm_fault+0x106 sys/uvm/uvm_fault.c:627
#4 upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192
#5 usertrap+0x430 sys/arch/amd64/amd64/trap.c:640
#6 recall_trap+0x8
shared rwlock vmmaplk r = 0 (0xfffff4806d146ab8)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 rw_do_enter_read+0x3e8 sys/kern/kern_rwlock.c:413
#2 uvmfault_lookup+0x122 sys/uvm/uvm_fault.c:1880
#3 uvm_fault_check+0x4f sys/uvm/uvm_fault.c:693
#4 uvm_fault+0x106 sys/uvm/uvm_fault.c:627
#5 upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192
#6 usertrap+0x430 sys/arch/amd64/amd64/trap.c:640
#7 recall_trap+0x8
Process 40217 (syz-executor) thread 0xffff800045fe2028 (388660)
exclusive rrwlock inode r = 0 (0xfffff48060e3eb30)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621
#3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527
#4 ufs_ihashins+0x4f ufs_ihash sys/ufs/ufs/ufs_ihash.c:-1 [inline]
#4 ufs_ihashins+0x4f sys/ufs/ufs/ufs_ihash.c:150
#5 ffs_vget+0x187 sys/ufs/ffs/ffs_vfsops.c:1232
#6 ffs_inode_alloc+0x279 sys/ufs/ffs/ffs_alloc.c:393
#7 ufs_makeinode+0xcd sys/ufs/ufs/ufs_vnops.c:1759
#8 ufs_create+0x4e sys/ufs/ufs/ufs_vnops.c:147
#9 VOP_CREATE+0xfe sys/kern/vfs_vops.c:103
#10 vn_open+0x50d sys/kern/vfs_vnops.c:118
#11 doopenat+0x35b sys/kern/vfs_syscalls.c:1163
#12 sys_open+0x59 sys/kern/vfs_syscalls.c:1065
#13 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#13 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#14 Xsyscall+0x128
exclusive rrwlock inode r = 0 (0xfffff48060e3ed80)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621
#3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527
#4 vn_lock+0xa4 sys/kern/vfs_vnops.c:576
#5 vfs_lookup+0x12b sys/kern/vfs_lookup.c:431
#6 namei+0x7c5 sys/kern/vfs_lookup.c:250
#7 vn_open+0x22e sys/kern/vfs_vnops.c:109
#8 doopenat+0x35b sys/kern/vfs_syscalls.c:1163
#9 sys_open+0x59 sys/kern/vfs_syscalls.c:1065
#10 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#10 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#11 Xsyscall+0x128
Process 68821 (syz-executor) thread 0xffff80002a222540 (372242)
exclusive rrwlock inode r = 0 (0xfffff4806cd5a560)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621
#3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527
#4 vn_lock+0xa4 sys/kern/vfs_vnops.c:576
#5 vfs_lookup+0x12b sys/kern/vfs_lookup.c:431
#6 namei+0x7c5 sys/kern/vfs_lookup.c:250
#7 sys_truncate+0x84 sys/kern/vfs_syscalls.c:2831
#8 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#8 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783
#9 Xsyscall+0x128
Process 68821 (syz-executor) thread 0xffff800045fe8fb0 (378288)
exclusive rrwlock inode r = 0 (0xfffff48060e3e440)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320
#2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621
#3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527
#4 vn_lock+0xa4 sys/kern/vfs_vnops.c:576
#5 vn_write+0x18f sys/kern/vfs_vnops.c:411
#6 dofilewritev+0x2bd sys/kern/sys_generic.c:384
#7 sys_write+0xa2 sys/kern/sys_generic.c:300
#8 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#8 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
#9 Xsyscall+0x128
ddb{0}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 11055 12017K 12034K 166960K 12149 0
pcb 17 12K 12K 166960K 17 0
rtable 223 6K 7K 166960K 383 0
pf 29 16K 16K 166960K 31 0
ifaddr 38 6K 7K 166960K 44 0
ifgroup 46 2K 2K 166960K 50 0
sysctl 4 1K 9K 166960K 9 0
counters 68 36K 37K 166960K 70 0
ioctlops 0 0K 4K 166960K 87 0
iov 0 0K 4K 166960K 19 0
mount 1 1K 1K 166960K 1 0
log 0 0K 0K 166960K 4 0
vnodes 1288 81K 81K 166960K 1544 0
UFS quota 1 32K 32K 166960K 1 0
UFS mount 5 36K 36K 166960K 5 0
shm 2 1K 9K 166960K 16 0
VM map 2 1K 1K 166960K 2 0
sem 12 1K 1K 166960K 33 0
dirhash 12 2K 2K 166960K 21 0
ACPI 1734 201K 291K 166960K 11964 0
file desc 23 85K 125K 166960K 695 0
sigio 0 0K 0K 166960K 24 0
proc 58 99K 147K 166960K 564 0
subproc 63 3K 4K 166960K 108 0
NFS srvsock 1 0K 0K 166960K 1 0
NFS daemon 1 16K 16K 166960K 1 0
ip_moptions 1 0K 0K 166960K 99 0
in_multi 88 6K 7K 166960K 123 0
ether_multi 1 0K 0K 166960K 3 0
mrt 0 0K 0K 166960K 17 0
ISOFS mount 1 32K 32K 166960K 1 0
MSDOSFS mount 1 16K 16K 166960K 1 0
ttys 109 493K 493K 166960K 109 0
exec 0 0K 1K 166960K 406 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 239 151K 178K 166960K 7918 0
UVM aobj 21 4K 4K 166960K 23 0
pinsyscall 44 88K 110K 166960K 1765 0
memdesc 1 4K 4K 166960K 1 0
crypto data 1 1K 1K 166960K 1 0
ip6_options 0 0K 0K 166960K 54 0
NDP 10 0K 2K 166960K 27 0
temp 41 9120K 9183K 166960K 4992 0
kqueue 15 22K 33K 166960K 190 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 28 0 0 1 0 1 1 0 8 0
rtpcb 120 77 0 74 1 0 1 1 0 8 0
rtentry 176 119 0 16 6 0 6 6 0 8 0
unpcb 144 513 0 492 4 1 3 4 0 8 2
syncache 336 12 0 12 1 0 1 1 0 8 1
tcpcb 736 250 0 245 4 2 2 4 0 8 1
arp 136 18 0 2 1 0 1 1 0 8 0
ipq 40 7 0 2 1 0 1 1 0 8 0
ipqe 40 76 0 69 1 0 1 1 0 8 0
inpcb 328 656 0 642 5 1 4 4 0 8 2
ip6q 72 2 0 1 2 1 1 1 0 8 0
ip6af 40 3 0 2 2 1 1 1 0 8 0
nd6 152 32 0 7 2 0 2 2 0 8 0
kcovpl 48 12 0 5 1 0 1 1 0 8 0
art_heap8 4096 1 0 0 1 0 1 1 0 8 0
art_heap4 256 509 0 80 30 0 30 30 0 8 1
art_table 40 510 0 80 5 0 5 5 0 8 0
art_node 32 119 0 25 1 0 1 1 0 8 0
sysvmsgpl 40 8 0 5 1 0 1 1 0 8 0
semupl 112 2 0 2 1 1 0 1 0 8 0
semapl 72 29 0 19 1 0 1 1 0 8 0
shmpl 112 20 0 2 1 0 1 1 0 8 0
dirhash 1024 23 0 6 3 0 3 3 0 8 0
dino2pl 256 2440 0 964 93 0 93 93 0 8 0
ffsino 296 2440 0 964 114 0 114 114 0 8 0
nchpl 144 3387 0 1685 64 0 64 64 0 8 0
vnodes 216 2557 0 0 143 0 143 143 0 8 0
namei 1024 10784 0 10782 2 1 1 2 0 8 0
percpumem 16 51 0 1 1 0 1 1 0 8 0
kstatmem 264 25 0 2 2 0 2 2 0 8 0
scxspl 216 10972 0 10972 10 7 3 8 1 8 3
plimitpl 152 151 0 129 2 0 2 2 0 8 1
sigapl 424 976 0 925 7 0 7 7 0 8 0
knotepl 120 531 0 0 16 0 16 16 0 8 0
kqueuepl 224 216 0 204 2 0 2 2 0 8 1
pipepl 344 343 0 314 9 0 9 9 0 8 6
fdescpl 528 960 0 925 4 0 4 4 0 8 0
filepl 160 5683 0 5463 17 2 15 17 0 8 5
lockfpl 104 199 0 197 1 0 1 1 0 8 0
lockfspl 48 71 0 69 1 0 1 1 0 8 0
sessionpl 144 119 0 104 1 0 1 1 0 8 0
pgrppl 48 140 0 118 1 0 1 1 0 8 0
ucredpl 104 1235 0 1217 1 0 1 1 0 8 0
zombiepl 144 925 0 925 1 0 1 1 0 8 1
processpl 1232 976 0 925 5 0 5 5 0 8 0
procpl 664 1870 0 1808 7 0 7 7 0 8 1
sosppl 176 6 0 6 1 0 1 1 0 8 1
sockpl 752 1248 0 1210 13 3 10 13 0 8 5
mcl64k 65536 5 0 0 1 0 1 1 0 8 0
mcl16k 16384 3 0 0 1 0 1 1 0 8 0
mcl9k128 9344 1 0 0 1 0 1 1 0 8 0
mcl8k 8192 4 0 0 1 0 1 1 0 8 0
mcl4k 4096 114 0 0 15 0 15 15 0 8 0
mcl2k2 2112 1 0 0 1 0 1 1 0 8 0
mcl2k 2048 19 0 0 3 0 3 3 0 8 0
mextrefs 64 19 0 0 1 0 1 1 0 8 0
mtagpl 96 3 0 0 1 0 1 1 0 8 0
mbufpl 256 1261 0 0 79 0 79 79 0 8 0
bufpl 272 3211 0 102 208 0 208 208 0 8 0
anonpl 32 7827 0 0 64 0 64 64 0 247 0
amapchunkpl 152 26592 0 26054 37 0 37 37 0 158 14
amappl16 200 2878 0 2838 21 10 11 15 0 8 8
amappl15 192 5 0 5 1 1 0 1 0 8 0
amappl14 184 403 0 402 1 0 1 1 0 8 0
amappl13 176 112 0 102 1 0 1 1 0 8 0
amappl12 168 1189 0 1155 2 0 2 2 0 8 0
amappl11 160 39 0 39 2 2 0 1 0 8 0
amappl10 152 60 0 50 1 0 1 1 0 8 0
amappl9 144 275 0 274 1 0 1 1 0 8 0
amappl8 136 107 0 106 1 0 1 1 0 8 0
amappl7 128 139 0 128 1 0 1 1 0 8 0
amappl6 120 154 0 152 1 0 1 1 0 8 0
amappl5 112 115 0 105 1 0 1 1 0 8 0
amappl4 104 256 0 240 1 0 1 1 0 8 0
amappl3 96 5053 0 4925 5 1 4 4 0 8 0
amappl2 88 508 0 454 2 0 2 2 0 8 0
amappl1 80 12391 0 11823 14 0 14 14 0 8 0
amappl 88 7178 0 7001 5 0 5 5 0 92 0
uvmvnodes 80 116 0 0 3 0 3 3 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 22 0 2 1 0 1 1 0 8 0
uaddrrnd 24 960 0 925 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 960 0 925 1 0 1 1 0 8 0
vmmpekpl 168 9805 0 9762 3 0 3 3 0 8 0
vmmpepl 168 67711 0 65705 105 1 104 104 0 357 13
vmsppl 488 959 0 925 7 1 6 6 0 8 0
rwobjpl 80 20764 0 19775 27 1 26 26 0 8 2
pdppl 4096 1927 0 1850 107 24 83 97 0 8 6
pvpl 32 14977 0 0 121 0 121 121 0 265 0
pmappl 256 959 0 925 4 1 3 3 0 8 0
extentpl 40 46 0 28 1 0 1 1 0 8 0
phpool 112 556 0 30 16 0 16 16 0 8 0
ddb{0}> machine ddbcpu 0
Invalid cpu 0
ddb{0}> trace
amap_lookups(fffff4806cb43c68,6000,ffff80003c1e5d70,8) at amap_lookups+0x1e0 amap_chunk_get sys/uvm/uvm_amap.c:118 [inline]
amap_lookups(fffff4806cb43c68,6000,ffff80003c1e5d70,8) at amap_lookups+0x1e0 sys/uvm/uvm_amap.c:1168
uvm_fault_check(ffff80003c1e5e70,ffff80003c1e5ea8,ffff80003c1e5ee0,0) at uvm_fault_check+0x8d2 sys/uvm/uvm_fault.c:840
uvm_fault(fffff4806d1469b8,53884bda000,0,1) at uvm_fault+0x106 sys/uvm/uvm_fault.c:627
upageflttrap(ffff80003c1e6010,53884bdab50) at upageflttrap+0xa9 sys/arch/amd64/amd64/trap.c:192
usertrap(ffff80003c1e6010) at usertrap+0x430 sys/arch/amd64/amd64/trap.c:640
recall_trap() at recall_trap+0x8
end of kernel
end trace frame: 0x7e4d0b786240, count: -6
ddb{0}> machine ddbcpu 1
Stopped at x86_ipi_db+0x27: addq $0x8,%rsp
ddb{1}> trace
x86_ipi_db(ffff80002999dff0) 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
end of kernel
end trace frame: 0x7848cc8b2f80, count: -3
Struck through repros no longer work on HEAD.