syzbot
assert "(dirblock < dh->dh_nblk && dh->dh_blkfree[dirblock] >= (((slotneeded) + ((NUM) - NUM)) / (NUM)))" failed in ufs_
Status:
upstream: reported on 2026/09/11 16:30
Reported-by: syzbot+a7449377d085bfe173d1@syzkaller.appspotmail.com
First crash: 10d, last: 10d
Sample crash report:
panic: kernel diagnostic assertion "(dirblock < dh->dh_nblk && dh->dh_blkfree[dirblock] >= (((slotneeded) + ((4) - 1)) / (4)))" failed: file "/syzkaller/managers/setuid/kernel/sys/ufs/ufs/ufs_dirhash.c", line 508
Stopped at db_enter+0x25: addq $0x8,%rsp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
109360 25045 32767 0x10 0 1 syz-executor
*453936 65866 0 0x2 0 0K syz-executor
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834c1e78) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff83501897,ffffffff8354788a,1fc,ffffffff8352a956) at __assert+0x29 sys/kern/subr_prf.c:-1
ufsdirhash_findfree(fffff1806ff2d3b0,1c,ffff80003839c4a8) at ufsdirhash_findfree+0x566 sys/ufs/ufs/ufs_dirhash.c:549
ufs_lookup() at ufs_lookup+0xe20 sys/ufs/ufs/ufs_lookup.c:202
VOP_LOOKUP(fffff1807014c898,ffff80003839c7f0,ffff80003839c820) at VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85
vfs_lookup(ffff80003839c7c0) at vfs_lookup+0x963 sys/kern/vfs_lookup.c:580
namei(ffff80003839c7c0) at namei+0x7c5 sys/kern/vfs_lookup.c:250
domkdirat(ffff800045ffdc90,ffffff9c,7b1c4c777a90,1c0) at domkdirat+0x8b sys/kern/vfs_syscalls.c:3048
syscall(ffff80003839c9a0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003839c9a0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:791
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7b1c4c777a50, 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{0}>
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
*cpu0: kernel diagnostic assertion "(dirblock < dh->dh_nblk && dh->dh_blkfree[dirblock] >= (((slotneeded) + ((4) - 1)) / (4)))" failed: file "/syzkaller/managers/setuid/kernel/sys/ufs/ufs/ufs_dirhash.c", line 508
ddb{0}> show kasan
No such command
ddb{0}> trace
db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438
panic(ffffffff834c1e78) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff83501897,ffffffff8354788a,1fc,ffffffff8352a956) at __assert+0x29 sys/kern/subr_prf.c:-1
ufsdirhash_findfree(fffff1806ff2d3b0,1c,ffff80003839c4a8) at ufsdirhash_findfree+0x566 sys/ufs/ufs/ufs_dirhash.c:549
ufs_lookup() at ufs_lookup+0xe20 sys/ufs/ufs/ufs_lookup.c:202
VOP_LOOKUP(fffff1807014c898,ffff80003839c7f0,ffff80003839c820) at VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85
vfs_lookup(ffff80003839c7c0) at vfs_lookup+0x963 sys/kern/vfs_lookup.c:580
namei(ffff80003839c7c0) at namei+0x7c5 sys/kern/vfs_lookup.c:250
domkdirat(ffff800045ffdc90,ffffff9c,7b1c4c777a90,1c0) at domkdirat+0x8b sys/kern/vfs_syscalls.c:3048
syscall(ffff80003839c9a0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003839c9a0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:791
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7b1c4c777a50, count: -11
ddb{0}> show registers
rdi 0
rsi 0x1
rbp 0xffff80003839c2f0
rbx 0xffffffff83940e0f cpu_info_full_primary+0x2e0f
rdx 0
rcx 0xffff800045ffdc90
rax 0xffffffff8393fff0 cpu_info_full_primary+0x1ff0
r8 0x101010101010101
r9 0x8080808080808080
r10 0x84fd5095f0a0f5fc
r11 0x5a66bc3d3dc33800
r12 0xffffffff83940c10 cpu_info_full_primary+0x2c10
r13 0
r14 0
r15 0x1
rip 0xffffffff8312b135 db_enter+0x25
cs 0x8
rflags 0x246
rsp 0xffff80003839c2e0
ss 0x10
db_enter+0x25: addq $0x8,%rsp
ddb{0}> show proc
PROC (syz-executor) tid=453936 pid=65866 tcnt=1 stat=onproc
flags process=2<EXEC> proc=0
runpri=50, usrpri=86, slppri=36, nice=20
wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
forw=0xffffffffffffffff, list=0xffff800045fe2a88,0xffff80002a22b780
process=0xffff800045fec9b8 user=0xffff800038397000, vmspace=0xfffff1800b1cb988
estcpu=36, cpticks=2, pctcpu=0.0, user=0, sys=2, intr=0
ddb{0}> ps
PID TID PPID UID S PRLAGS PFLAGS WAIT COMMAND
45893 171191 2008 0 2 0 0 syz-executor
60141 262930 91961 32767 2 0x10 0 syz-executor
25045 109360 24683 32767 7 0x10 0 syz-executor
*65866 453936 2008 0 7 0x2 0 syz-executor
24683 499790 57993 32767 2 0x10 0xc80 syz-executor
57993 225475 2008 0 3 0x2 0x80 wait syz-executor
91961 370109 40752 32767 2 0x10 0xc80 syz-executor
40752 323163 2008 0 3 0x2 0x80 wait syz-executor
59943 136029 55912 32767 3 0x10 0x80 wait syz-executor
55912 338822 2008 0 3 0x2 0x80 wait syz-executor
22309 231633 97541 32767 3 0x10 0x80 wait syz-executor
97541 453416 2008 0 3 0x2 0x80 wait syz-executor
42924 315959 46653 32767 3 0x10 0x80 wait syz-executor
46653 94302 2008 0 3 0x2 0x80 wait syz-executor
14358 188875 93418 0 3 0x100002 0x80 sbwait ndp
93418 906 18984 0 3 0x100002 0x88 sigsusp sh
18984 305340 10933 0 3 0 0x80 wait syz-executor
10933 279467 2008 0 3 0x2 0x80 wait syz-executor
2008 330516 98328 0 3 0x2 0x80 kqread syz-executor
98328 316129 71181 0 3 0x100002 0x88 sigsusp ksh
71181 480019 11108 0 3 0x10 0x88 kqread sshd-session
11108 498742 77207 0 3 0x12 0x80 kqread sshd-session
2434 408040 1 0 3 0x100003 0x80 ttyin getty
77207 43375 1 0 3 0 0x88 kqread sshd
53524 146269 28959 73 3 0x1100010 0x80 kqread syslogd
28959 24781 1 0 3 0x100002 0x80 sbwait syslogd
59441 106955 1 0 3 0x100000 0x80 kqread resolvd
8287 520307 35060 77 3 0x100012 0x80 kqread dhcpleased
19328 391160 35060 77 3 0x100012 0x80 kqread dhcpleased
35060 159253 1 0 3 0 0x80 kqread dhcpleased
49381 270535 0 0 3 0x14000 0x200 bored smr
6220 462907 0 0 2 0x14000 0x200 zerothread
73152 374438 0 0 3 0x14000 0x200 aiodoned aiodoned
94935 115538 0 0 3 0x14000 0x200 syncer update
14622 279939 0 0 3 0x14000 0x200 cleaner cleaner
54297 44249 0 0 3 0x14000 0x200 reaper reaper
45852 117944 0 0 3 0x14000 0x200 pgdaemon pagedaemon
89326 293321 0 0 3 0x14000 0x200 bored viomb
78042 348327 0 0 3 0x14000 0x40000200 acpi0 acpi0
13179 74694 0 0 3 0x14000 0x40000200 idle1
99201 372126 0 0 3 0x14000 0x200 bored softnet1
86452 134540 0 0 2 0x14000 0x200 softnet0
90023 88741 0 0 3 0x14000 0x200 smrbar systqmp
58460 325165 0 0 3 0x14000 0x200 bored systq
84697 342855 0 0 3 0x14000 0x200 tmoslp softclockmp
23208 55350 0 0 3 0x14000 0x40000200 tmoslp softclock
15454 417388 0 0 3 0x14000 0x40000200 idle0
1 439245 0 0 3 0x2 0x80 wait init
0 0 -1 0 3 0x10000 0x200 scheduler swapper
ddb{0}> show all locks
Process 25045 (syz-executor) thread 0xffff80002a22b770 (109360)
exclusive rwlock vmmaplk r = 0 (0xfffff1800b1cb4d0)
#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 vm_map_lock_ln+0x12e sys/uvm/uvm_map.c:5170
#3 uvm_mapanon+0x28f sys/uvm/uvm_map.c:-1
#4 uvm_mmapanon+0x1d0 sys/uvm/uvm_mmap.c:1029
#5 sys_mmap+0xa80 sys/uvm/uvm_mmap.c:426
#6 syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#6 syscall+0xbd4 sys/arch/amd64/amd64/trap.c:791
#7 Xsyscall+0x128
Process 65866 (syz-executor) thread 0xffff800045ffdc90 (453936)
exclusive rwlock dirhash r = 0 (0xffff800001633818)
#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 ufsdirhash_findfree+0x55 sys/ufs/ufs/ufs_dirhash.c:490
#3 ufs_lookup+0xe20 sys/ufs/ufs/ufs_lookup.c:202
#4 VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85
#5 vfs_lookup+0x963 sys/kern/vfs_lookup.c:580
#6 namei+0x7c5 sys/kern/vfs_lookup.c:250
#7 domkdirat+0x8b sys/kern/vfs_syscalls.c:3048
#8 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#8 syscall+0xb17 sys/arch/amd64/amd64/trap.c:791
#9 Xsyscall+0x128
exclusive rrwlock inode r = 0 (0xfffff1806ff2d450)
#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 domkdirat+0x8b sys/kern/vfs_syscalls.c:3048
#8 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#8 syscall+0xb17 sys/arch/amd64/amd64/trap.c:791
#9 Xsyscall+0x128
exclusive kernel_lock &kernel_lock r = 0 (0xffffffff839f87c0)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline]
#1 syscall+0xaf4 sys/arch/amd64/amd64/trap.c:791
#2 Xsyscall+0x128
Process 90023 (systqmp) thread 0xffff800045ffe7c8 (88741)
shared rwlock systqmp r = 0 (0xffffffff83912d88)
#0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160
#1 taskq_thread+0x12a sys/kern/kern_task.c:442
#2 proc_trampoline+0x10
ddb{0}> show malloc
Type InUse MemUse HighUse Limit Requests Type Lim
devbuf 11048 12014K 12034K 166960K 12298 0
pcb 17 12K 12K 166960K 17 0
rtable 199 5K 7K 166960K 1901 0
pf 27 16K 16K 166960K 133 0
ifaddr 35 6K 7K 166960K 252 0
ifgroup 42 1K 2K 166960K 254 0
sysctl 1 1K 9K 166960K 7 0
counters 66 36K 37K 166960K 172 0
ioctlops 0 0K 4K 166960K 125 0
iov 0 0K 24K 166960K 13 0
mount 1 1K 1K 166960K 1 0
log 0 0K 0K 166960K 4 0
vnodes 1287 81K 81K 166960K 2014 0
UFS quota 1 32K 32K 166960K 1 0
UFS mount 5 36K 36K 166960K 5 0
shm 2 1K 9K 166960K 12 0
VM map 2 1K 1K 166960K 2 0
sem 25 3K 3K 166960K 28 0
dirhash 18 3K 3K 166960K 24 0
ACPI 1692 195K 286K 166960K 12470 0
file desc 23 79K 129K 166960K 1328 0
sigio 0 0K 0K 166960K 18 0
proc 58 99K 180K 166960K 1966 0
subproc 54 3K 4K 166960K 666 0
NFS srvsock 1 0K 0K 166960K 1 0
NFS daemon 1 16K 16K 166960K 1 0
ip_moptions 0 0K 0K 166960K 69 0
in_multi 77 5K 6K 166960K 667 0
ether_multi 1 0K 0K 166960K 2 0
mrt 1 0K 0K 166960K 23 0
ISOFS mount 1 32K 32K 166960K 1 0
MSDOSFS mount 1 16K 16K 166960K 1 0
ttys 85 387K 387K 166960K 85 0
exec 0 0K 1K 166960K 1202 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 218 137K 188K 166960K 10776 0
UVM aobj 15 2K 2K 166960K 16 0
pinsyscall 45 90K 118K 166960K 3776 0
memdesc 1 4K 4K 166960K 1 0
crypto data 1 1K 1K 166960K 1 0
ip6_options 0 0K 0K 166960K 30 0
NDP 9 0K 2K 166960K 180 0
temp 67 9127K 9144K 166960K 11876 0
kqueue 13 20K 26K 166960K 79 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 120 169 0 165 1 0 1 1 0 8 0
rtentry 176 673 0 582 6 0 6 6 0 8 1
unpcb 144 519 0 504 3 2 1 3 0 8 0
syncache 336 8 0 8 1 0 1 1 0 8 1
tcpqe 32 1 0 1 1 1 0 1 0 8 0
tcpcb 736 204 0 198 7 4 3 7 0 8 2
arp 136 121 0 105 1 0 1 1 0 8 0
ipq 40 3 0 1 1 0 1 1 0 8 0
ipqe 40 4 0 2 1 0 1 1 0 8 0
inpcb 328 734 0 723 7 2 5 7 0 8 3
ip6q 80 2 0 1 1 0 1 1 0 8 0
ip6af 40 3 0 2 1 0 1 1 0 8 0
nd6 152 177 0 160 1 0 1 1 0 8 0
kcovpl 48 74 0 68 1 0 1 1 0 8 0
art_heap8 4096 1 0 0 1 0 1 1 0 8 0
art_heap4 256 2726 0 2316 38 7 31 32 0 8 5
art_table 40 2727 0 2316 6 0 6 6 0 8 0
art_node 32 673 0 583 1 0 1 1 0 8 0
sysvmsgpl 40 1 0 0 1 0 1 1 0 8 0
semupl 112 3 0 3 2 1 1 1 0 8 1
semapl 72 24 0 1 1 0 1 1 0 8 0
shmpl 112 13 0 1 1 0 1 1 0 8 0
dirhash 1024 25 0 4 3 0 3 3 0 8 0
dino2pl 256 2157 0 540 102 0 102 102 0 8 0
ffsino 296 2157 0 540 125 0 125 125 0 8 0
nchpl 144 2801 0 921 70 0 70 70 0 8 0
vnodes 216 2832 0 0 158 0 158 158 0 8 0
namei 1024 15745 0 15744 4 2 2 2 0 8 1
percpumem 16 102 0 53 1 0 1 1 0 8 0
kstatmem 264 127 0 106 2 0 2 2 0 8 0
scxspl 216 9454 0 9454 8 4 4 4 1 8 4
plimitpl 152 224 0 203 2 0 2 2 0 8 0
sigapl 424 1499 0 1448 7 0 7 7 0 8 0
knotepl 120 347 0 0 11 0 11 11 0 8 0
kqueuepl 224 114 0 105 2 0 2 2 0 8 1
pipepl 344 422 0 391 9 1 8 9 0 8 5
fdescpl 528 1483 0 1448 4 0 4 4 0 8 0
filepl 160 5678 0 5474 15 1 14 15 0 8 4
lockfpl 104 161 0 159 1 0 1 1 0 8 0
lockfspl 48 42 0 40 1 0 1 1 0 8 0
sessionpl 144 239 0 223 1 0 1 1 0 8 0
pgrppl 48 321 0 298 1 0 1 1 0 8 0
ucredpl 104 776 0 760 1 0 1 1 0 8 0
zombiepl 144 1451 0 1448 1 0 1 1 0 8 0
processpl 1232 1499 0 1448 5 0 5 5 0 8 0
procpl 664 2146 0 2095 7 0 7 7 0 8 0
sosppl 176 4 0 4 1 1 0 1 0 8 0
sockpl 752 1462 0 1432 10 2 8 10 0 8 4
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 133 0 0 17 0 17 17 0 8 0
mcl2k2 2112 1 0 0 1 0 1 1 0 8 0
mcl2k 2048 42 0 0 6 0 6 6 0 8 0
mextrefs 64 42 0 0 1 0 1 1 0 8 0
mtagpl 96 1 0 0 1 0 1 1 0 8 0
mbufpl 256 1223 0 0 76 0 76 76 0 8 0
bufpl 272 3081 0 105 199 0 199 199 0 8 0
anonpl 32 5246 0 0 43 0 43 43 0 247 0
amapchunkpl 152 30260 0 29802 35 2 33 34 0 158 11
amappl16 200 2066 0 2050 6 4 2 5 0 8 0
amappl15 192 6 0 6 1 1 0 1 0 8 0
amappl14 184 1032 0 1029 1 0 1 1 0 8 0
amappl13 176 218 0 207 1 0 1 1 0 8 0
amappl12 168 1924 0 1893 2 0 2 2 0 8 0
amappl11 160 4 0 4 1 1 0 1 0 8 0
amappl10 152 60 0 50 1 0 1 1 0 8 0
amappl9 144 267 0 267 1 1 0 1 0 8 0
amappl8 136 301 0 300 1 0 1 1 0 8 0
amappl7 128 246 0 234 1 0 1 1 0 8 0
amappl6 120 683 0 681 1 0 1 1 0 8 0
amappl5 112 103 0 94 1 0 1 1 0 8 0
amappl4 104 439 0 422 1 0 1 1 0 8 0
amappl3 96 5429 0 5339 4 0 4 4 0 8 1
amappl2 88 1420 0 1344 2 0 2 2 0 8 0
amappl1 80 18829 0 18233 17 3 14 17 0 8 0
amappl 88 9113 0 8962 5 0 5 5 0 92 0
uvmvnodes 80 115 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 15 0 1 1 0 1 1 0 8 0
uaddrrnd 24 1483 0 1448 1 0 1 1 0 8 0
uaddrbest 32 2 0 0 1 0 1 1 0 8 0
uaddr 24 1483 0 1448 1 0 1 1 0 8 0
vmmpekpl 168 13377 0 13304 4 0 4 4 0 8 0
vmmpepl 168 102065 0 100100 98 1 97 97 0 357 6
vmsppl 488 1482 0 1448 7 1 6 6 0 8 1
rwobjpl 80 29826 0 28852 25 2 23 25 0 8 0
pdppl 4096 2973 0 2896 157 76 81 99 0 8 4
pvpl 32 12370 0 0 100 0 100 100 0 265 0
pmappl 256 1482 0 1448 4 1 3 3 0 8 0
extentpl 40 45 0 27 1 0 1 1 0 8 0
phpool 112 620 0 92 16 0 16 16 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(ffffffff834c1e78) at panic+0x1e5 sys/kern/subr_prf.c:198
__assert(ffffffff83501897,ffffffff8354788a,1fc,ffffffff8352a956) at __assert+0x29 sys/kern/subr_prf.c:-1
ufsdirhash_findfree(fffff1806ff2d3b0,1c,ffff80003839c4a8) at ufsdirhash_findfree+0x566 sys/ufs/ufs/ufs_dirhash.c:549
ufs_lookup() at ufs_lookup+0xe20 sys/ufs/ufs/ufs_lookup.c:202
VOP_LOOKUP(fffff1807014c898,ffff80003839c7f0,ffff80003839c820) at VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85
vfs_lookup(ffff80003839c7c0) at vfs_lookup+0x963 sys/kern/vfs_lookup.c:580
namei(ffff80003839c7c0) at namei+0x7c5 sys/kern/vfs_lookup.c:250
domkdirat(ffff800045ffdc90,ffffff9c,7b1c4c777a90,1c0) at domkdirat+0x8b sys/kern/vfs_syscalls.c:3048
syscall(ffff80003839c9a0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003839c9a0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:791
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7b1c4c777a50, count: -11
ddb{0}> machine ddbcpu 1
Stopped at x86_ipi_db+0x27: addq $0x8,%rsp
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
__mp_lock(ffffffff839f7fc0) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff839f7fc0) at __mp_lock+0x192 sys/kern/kern_lock.c:173
syscall(ffff80002bb906d0) at syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline]
syscall(ffff80002bb906d0) at syscall+0xaf4 sys/arch/amd64/amd64/trap.c:791
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7292cda46990, count: 9
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
__mp_lock(ffffffff839f7fc0) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:142 [inline]
__mp_lock(ffffffff839f7fc0) at __mp_lock+0x192 sys/kern/kern_lock.c:173
syscall(ffff80002bb906d0) at syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline]
syscall(ffff80002bb906d0) at syscall+0xaf4 sys/arch/amd64/amd64/trap.c:791
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7292cda46990, count: -6
Struck through repros no longer work on HEAD.