[geom] page fault in g_mbr_config()

[pluknet]

Hi.

I got a panic while performing a repetitive  'fdisk -BI aacd0',
where aacd0 is a disk on aac0: <IBM ServeRAID-8k>.
This means that the command was issued after filesystems
were already created on aacd (after the first fdisk -BI aacd0
iteration), and are in umount'ed state.

This is on 7.2-R, amd64. Config is a GENERIC plus ddb, carp, ipfw, quota.

Fatal trap 12: page fault while in kernel mode
cpuid = 5; apic id = 05
fault virtual address   = 0x20
fault code              = supervisor read data, page not present
instruction pointer     = 0x8:0xffffffff804cc554
stack pointer           = 0x10:0xfffffffe80079b80
frame pointer           = 0x10:0xfffffffe80079bd0
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 2 (g_event)
[thread pid 2 tid 100013 ]
Stopped at      g_mbr_config+0x64:      movq    0x20(%rax),%r15
db> bt
Tracing pid 2 tid 100013 td 0xffffff000144da50
g_mbr_config() at g_mbr_config+0x64
g_run_events() at g_run_events+0x1b8
g_event_procbody() at g_event_procbody+0x57
fork_exit() at fork_exit+0x11f
fork_trampoline() at fork_trampoline+0xe
--- trap 0, rip = 0, rsp = 0xfffffffe80079d30, rbp = 0 ---


-- 
wbr,
pluknet