4.0/amd64 pagedaemon panic in uvm_map_lookup_entry

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

I recently had the following panic on a 4.0/amd64 machine.
Everything below has been manually typed in from photographs taken from the 
console screen. I don't have a dump.

kernel: protection fault trap, code=0
Stopped in pid 15.1 (pagedaemon) at     netbsd:uvm_map_lookup_entry+0x1b:       
cmpq    %rsi,0x40(%rax)
db> show registers
ds      0x8400
es      0x1068
fs      0x800
gs      0x1068
rdi     0xffff800007c70000
rsi     0xffff80000003000e
rbp     0xffff800007c70000
rbx     0xffff800007c70000
rdx     0xffff80004e8cccd0
rcx     0xffff800007c70048
rax     0x3000e4c86f658
r8      0xffff80004e8ccd20
r9      0x2800000
r10     0
r11     0x1
r12     0xffff80000003000e
r13     0xffff80000003000e
r14     0x2800000
r15     0xffff80004e8ccd20
rip     0xffffffff8029d4bc      uvm_map_lookup_entry+0x1b
cs      0x8
rflags  0x10203
rsp     0xffff80004e8ccca8
ss      0
netbsd:uvm_map_lookup_entry+0x1b:       cmpq    %rsi,0x40(%rax)
db> bt
uvm_map_lookup_entry() at netbsd:uvm_map_lookup_entry+0x1b
?() at 0x3000e00000000
uvm_fault(0xffffffff896a5499, 0xffffffff00030000,1) -> e
kernel: page fault trap, code=0
faultet in DDB; continuing...
db>