uvm_fault(0xfffffd806b715010, 0x8, 0, 1) -> e
fatal page fault in supervisor mode
trap type 6 code 0 rip ffffffff81068c5e cs 8 rflags 10246 cr2 8 cpl 0 rsp ffff80002fe657b0
gsbase 0xffff800020d68ff0  kgsbase 0x0
panic: trap type 6, code=0, pc=ffffffff81068c5e
Starting stack trace...
panic(ffffffff82742242) at panic+0x16b sys/kern/subr_prf.c:229
kerntrap(ffff80002fe65700) at kerntrap+0x1c7 sys/arch/amd64/amd64/trap.c:327
alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b
fifo_write(ffff80002fe65800) at fifo_write+0x4e sys/miscfs/fifofs/fifo_vnops.c:271
VOP_WRITE(fffffd806e15cdc8,ffff80002fe658b8,3,fffffd807f7d7138) at VOP_WRITE+0xbf sys/kern/vfs_vops.c:245
ktrwriteraw(ffff8000212a8598,fffffd806e15cdc8,fffffd807f7d7138,ffff80002fe65980,ffff80002fe65960) at ktrwriteraw+0x15f sys/kern/kern_ktrace.c:660
ktrgenio(ffff8000212a8598,f8,1,ffff800000d77280,c) at ktrgenio+0x292 ktrwrite2 sys/kern/kern_ktrace.c:624 [inline]
ktrgenio(ffff8000212a8598,f8,1,ffff800000d77280,c) at ktrgenio+0x292 sys/kern/kern_ktrace.c:259
dofilewritev(ffff8000212a8598,f8,ffff80002fe65b08,0,ffff80002fe65bf0) at dofilewritev+0x397 sys/kern/sys_generic.c:396
sys_write(ffff8000212a8598,ffff80002fe65ba0,ffff80002fe65bf0) at sys_write+0x83 sys/kern/sys_generic.c:295
syscall(ffff80002fe65c70) at syscall+0x4c2 mi_syscall sys/sys/syscall_mi.h:101 [inline]
syscall(ffff80002fe65c70) at syscall+0x4c2 sys/arch/amd64/amd64/trap.c:599
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffcdc30, count: 246
End of stack trace.

dump to dev 4,1 not possible