Bug 68083

	Kernel trap 9: general protection fault while in kernel mode
	when booting FreeBSD 5-CURRENT (snapshot 20040324) amd64 just after
	cdrom drive probe.  This happens every time I boot from this cd 
	(I burned several copies on different machines and checked md5 
	checksum) When booting 5.2.1-RELEASE (amd64) the system hangs at
	this points and keyboard input (Ctrl-Alt-Del) has no effect. I can 
	boot 5.2.1-RELEASE i386, 4.9-RELEASE, and DragonFlyBSD 1.0-CURRENT
	and have done numerous buildworlds as a rudementary test of hardware
	with no problems.  This happens with ACPI disabled as well.

[THIS IS HAND TRANSCRIBED]

acd0: CDROM <CREATIVE CD5230E> at ata1-slave PIO4
Kernel trap 9 with interrupts disabled

Fatal trap 9: general protection fault while in Kernel mode
cpuid = 0; apic id = 00
intruction pointer			= 0x8:0xffffffff804b1cc4
stack pointer						= 0x10:0xffffffff98147bb0
frame pointer						= 0x10:0xffffffff98147bc0
code segment						= base rx0, limit 0xfffff, type 0x1b
												= DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags				= resume, IOPL = 0
current process					= 9 (pagezero)
kernel: type 9 trap, code = 0
Stopped at 	vm_pageq_remove_nowakeup+0x2c: decl %eax
db> trace
vm_pageq_remove_nowakeup() at vm_pageq_remove_nowakeup+0x2c
vm_page_zero_idle() at vm_page_zero_idle+0x88
vm_pagezero() at vm_pagezero+0xad
fork_exit() at fork_exit+0x9f
fork_trampoline() at fork_trampoline+0xe
--- trap 0, rip = 0, rsp = 0xffffffff98147d00, rbp = 0 ---
db>

How-To-Repeat: 	boot with 5-CURRENT (snapshot 20040324) cd