kern/44417: immediate uvm_fault on boot w/ latest -current

[bch%methodlogic.net@localhost]

>Number:         44417
>Category:       kern
>Synopsis:       kernel faults immediately after/during hardware detection
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jan 19 17:25:00 +0000 2011
>Originator:     bch%methodlogic.net@localhost
>Release:        NetBSD 5.99.43
>Organization:
        Method Logic Digital (http://methodlogic.net/)
>Environment:
System: NetBSD kamloops 5.99.43 NetBSD 5.99.43 (kamloops) #157: Sat Jan 15 
11:02:49 PST 2011 root@kamloops:/usr/obj/sys/arch/amd64/compile/kamloops amd64
Architecture: x86_64
Machine: amd64
>Description:

Kernel has been failing for last ~30 hours: was initially failing on ehci 
hardware detection (hang), and did later fault w/ uvm failure as described here.

        Transcription of boot failure (boot -z):

        Detecting hardware... ifmedia_set: no match for 0x20/0xfffffff
        uvm_fault(oxffffffff80b41aa0, 0xfffffffffffff000,2)->e

        fatal page fault in supervisor mode
        trap type 6 code 2 rip ffffffff80625416 cd 8 rflags 10246 cr2 
ffffffffffffffff
        cpl 8 rsp ffffffff80cb1360
        kernel: page fault trap, code=0
        Stopped in pid 0.1 (system) at netbsd: uvm_pglist_add+0x36: movq 
%rdx,0(%rax)


Backtrace (function names only) as follows:

uvm_pglist_add()
uvm_pglistalloc()
_bus_dmamem_alloc_range()
_bus_dmamem_alloc()
_bus_dmamap_create()
_iwn_attach()
Backtrace (function names only) as follows:

uvm_pglist_add()
uvm_pglistalloc()
_bus_dmamem_alloc_range()
_bus_dmamem_alloc()
_bus_dmamap_create()
_iwn_attach()
...
>How-To-Repeat:
        Build kernel w/ latest code, reboot
>Fix: