ACPI crash with recent changes

Kernel sync'd up as of about half an hour ago no longer pxeboot's in my
test environment:

/boot/kernel/acpi.ko text=0x40978 data=0x17e4+0x116c
syms=[0x4+0x6360+0x4+0x815a]
Copyright (c) 1992-2004 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
        The Regents of the University of California. All rights reserved.
FreeBSD 5.2-CURRENT #7: Wed Mar  3 22:37:23 EST 2004

rwatson_at_cboss.rv.nailabs.com:/data/p4/rwatson/projects/netperf_socket/sys/i386/compile/MY
WARNING: WITNESS option enabled, expect reduced performance.
Preloaded elf kernel "/boot/kernel/kernel" at 0xc0a98000.
Preloaded elf module "/boot/kernel/acpi.ko" at 0xc0a981a4.
kernel trap 12 with interrupts disabled


Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0xc1046fdc
fault code              = supervisor read, page not present
instruction pointer     = 0x8:0xc07c20e2
stack pointer           = 0x10:0xc0c21c7c
frame pointer           = 0x10:0xc0c21ce0
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = resume, IOPL = 0
current process         = 0 ()
kernel: type 12 trap, code=0
Stopped at      contigmalloc1+0x362:    movl    -0x24(%edi,%eax,1),%edx
db> trace
contigmalloc1(1000,c08c79a0,1,0,9ffff) at contigmalloc1+0x362
contigmalloc(1000,c08c79a0,1,0,9ffff) at contigmalloc+0x6b
bus_dmamem_alloc(c128a580,c0a88744,1,c0a887a8,ffffffff) at
bus_dmamem_alloc+0xcd
acpi_alloc_wakeup_handler(0,c1ec00,c1e000,c1ec00,c1e000) at
acpi_alloc_wakeup_handler+0xb9
mi_startup() at mi_startup+0xb5
begin() at begin+0x2c
db> 

Kernel from 48 hours ago works fine.  I'll try to take a look at this in
detail tomorrow morning if no one else has got to it by then.

Thanks,

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert_at_fledge.watson.org      Senior Research Scientist, McAfee Research