[Rack] r00ter pooped itself

[Jonathan Lassoff]

It seems like r00ter rebooted itself a few times since last night and
came back up ok those times, but just now it panicked.

The serial logging from ops.noise shows:

...
tardirs: extracting var
setting tty flags
pf enabled
net.inet.carp.preempt: 0 -> 1
net.inet6.ip6.accept_rtadv: 0 -> 0
net.inet6.ip6.forwarding: 0 -> 1
net.inet.ip.forwarding: 0 -> 1
starting network
ifconfig: prefix prefixlen: invalid
uvm_fault(0xd0c5f760, 0xd570a000, 0, 1) -> e
^Mkernel: page fault trap, code=0
^MStopped at      bcopy+0x1a:     repe movsl      (%esi),%es:(%edi)
^Mddb>
^Mddb>