panic: trap type NUM, code=NUM, pc=NUM (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 181c8b93219b Use the same system register alias trick as w..
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=17dcf7df980000
kernel config: https://syzkaller.appspot.com/x/.config?x=7058272de1526588
dashboard link: https://syzkaller.appspot.com/bug?extid=ca35fda25c88a309cc36

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d6363d7a028f/disk-181c8b93.raw.xz
bsd.gdb: https://storage.googleapis.com/syzbot-assets/3896c93d893c/bsd-181c8b93.gdb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/acaac1db662e/kernel-181c8b93.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ca35fd...@syzkaller.appspotmail.com

panic: trap type 6, code=10, pc=0
Starting stack trace...
panic(ffffffff83315bb0) at panic+0x1d0 sys/kern/subr_prf.c:229
kerntrap(ffff80002a480c80) at kerntrap+0x29b sys/arch/amd64/amd64/trap.c:327
alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b
0(fffffd807bcbdf10,fffffd807bcbdf10,0,fffffd807bcbdf10,f4,0) at 0
softclock_process_kclock_timeout(fffffd807bcbdf10,0) at softclock_process_kclock_timeout+0x2a2 sys/kern/kern_timeout.c:692
softclock(0) at softclock+0x199 sys/kern/kern_timeout.c:745
softintr_dispatch(0) at softintr_dispatch+0xf6 sys/arch/amd64/amd64/softintr.c:90
Xsoftclock() at Xsoftclock+0x27
end of kernel
end trace frame: 0x704120604b40, count: 249
End of stack trace.

dump to dev 4,1 not possible
rebooting...
SeaBIOS (version 1.8.2-google)
Total RAM Size = 0x0000000080000000 = 2048 MiB
CPUs found: 2 Max CPUs supported: 2
SeaBIOS (version 1.8.2-google)
Machine UUID 389fa873-dfcb-7256-506e-5266d86d0b3b
found virtio-scsi at 0:3
virtio-scsi vendor='Google' product='PersistentDisk' rev='1' type=0 removable=0
virtio-scsi blksize=512 sectors=4194304 = 2048 MiB
drive 0x000f27d0: PCHS=0/0/0 translation=lba LCHS=520/128/63 s=4194304
Sending Seabios boot VM event.
Booting from Hard Disk 0...
>> OpenBSD/amd64 BOOT 3.67
boot> set $lines = 0
set: syntax error
boot> set $maxwidth = 0
set: syntax error
boot> show panic
boot: illegal argument panic
boot> trace
boot> show registers
boot> show proc
boot> ps
boot> show all locks
boot> show malloc
boot> show all pools
boot> machine ddbcpu 0
machine: syntax error
boot> trace
boot> machine ddbcpu 1
machine: syntax error
boot> trace


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