Panic: Fatal trap 12: page fault while in kernel mode

Hi,

I was playing around with CAM and got this reproducible panic:

Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0x46
fault code              = supervisor read, page not present
instruction pointer     = 0x:0xc03962fe
stack pointer           = 0x10:0xd835b9b4
frame pointer           = 0x10:0xd835ba24
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 585 (dvdtest)
kernel: type 12 trap, code=0
Stoppes at generic_bcopy+0x1a: repe mocsl (%esi),%es:(%edi)
db> tr
generic_bcopy(c4034780,c4205000,d835ba58,c0136c42,c4034780) at 
generic_bcopy+0x1a
sbp_action(c4034780,c4205000,c0136953,c41f1400,c4205000) at sbp_action+0x18
xpt_run_dev_sendq(c4034740,c41f1418,0,d835ba8c,c027895f)at 
xpt_run_dev_dendq+0x192
xtp_action(c4205000,0,c41f1430,c4202000,c4205000) at xpt_action+0x238
cam_periph_runccb(c4205000,0,2,1,c40fb960) at cam_periph_runccb+0x48
passsendcbb(c41e6500,c4205000,c4203400,c462920) at passsendccb+0xc7
passioctl(c4213100,c2601502,c4203400,3,c401fbe0) at passioctl+0xf0
spec_ioctl(d835bb7c,d835bc28,c02c34a1,d835bb7c,c025454d) at spec_ioctl+0x19e
spec_vnoperate(d835bb7c,c025454d,c0460ea0,1,c0447b00) at spec_vnoperate+0x18
vn_ioctl(c422c330,c2601502,c4203400,c42c9480,c401fbe0) at vn_ioctl+0x1a1
ioctl(c401fbe0,d835bd10,c03f9491,3ec,3) at ioctl+0x475
syscall(2f,2f,2f,bfbffb90,bfbff910) at syscall+0x273
Xint0x80_syscall() at Xint0x80_syscall+0x1d
--- syscall (54, FreeBSD ELF32, ioctl), eip = 0x281a354f, esp = 0xbfbff8dc, 
ebp = 0xbfbff8f8 ---
db >

Kernel is from this morning with up to date sources and ATAPICAM built in:

FreeBSD cheops.phoenix 5.1-CURRENT FreeBSD 5.1-CURRENT #7: Sun Sep 21 14:05:38 
CEST 2003     brueffer_at_cheops.phoenix:/usr/obj/usr/src/sys/CHEOPS  i386

If you need further information or the source that caused the panic, please 
let me know.

Regards,

Markus

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