vkernel pid=31513
=== console after mount attempt ===
sh: can't access tty; job control turned off
# echo VK-SHELL-READY
VK-SHELL-READY
# /bin/vkmount /dirfs-host /hostroot
dirfs mounted: /dirfs-host -> /hostroot
# === swapped: /dirfs-host is now a dangling symlink ===
lrwxr-xr-x  1 root  wheel         16 Sep  8 17:46 dirfs-host -> /nonexistent-xyz
drwxr-xr-x  1 root  wheel          0 Sep  8 17:46 dirfs-host.real
=== console tail after trigger ===
Mounting devfs
Cannot read termcap database;
using dumb terminal settings.
sh: can't access tty; job control turned off
# echo VK-SHELL-READY
VK-SHELL-READY
# /bin/vkmount /dirfs-host /hostroot
dirfs mounted: /dirfs-host -> /hostroot
# echo MOUNT-DONE
MOUNT-DONE
# ls /hostroot


Fatal trap 12: page fault while in kernel mode
cpuid = 0
fault virtual address	= 0x128
fault code		= supervisor read, page not present
instruction pointer	= 0x2b:0x72080b
stack pointer	        = 0x10:0x8014317080
frame pointer	        = 0x10:0x8014317620
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 3 (ls)
current thread          = pri 6 
 <- SMP: XXX
kernel: type 12 trap, code=0

CPU0 stopping CPUs: 0x0000000000000002
 stopped
Stopped at      0x72080b:       movq    $0,0x128(%r13)
db> RESULT: vkernel still alive