kern/188187: [10-STABLE] [ZFS] Kernel panic on zpool import: integer divide fault

[arrowdodger]

>Number:         188187
>Category:       kern
>Synopsis:       [10-STABLE] [ZFS] Kernel panic on zpool import: integer divide fault
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Apr 02 06:40:00 UTC 2014
>Closed-Date:
>Last-Modified:
>Originator:     arrowdodger
>Release:        10.0-STABLE-amd64-20140329-r263906
>Organization:
>Environment:
>Description:
I have root on ZFS and using 10-STABLE. Somewhere from March 15 i started to get following panic when mounting root:

Fatal trap 18: integer divide fault while in kernel mode
Fatal trap 18: integer divide fault while in kernel mode
cpuid = 0; cpuid = 1; apic id = 00
apic id = 01
instruction pointer     = 0x20:0xffffffff81a7f92d
instruction pointer     = 0x28:0xffffffff81a7f92d
stack pointer           = 0x28:0xfffffe0097a8b100
stack pointer           = 0x28:0xfffffe0097a12ba0
frame pointer           = 0x28:0xfffffe0097a8b120
frame pointer           = 0x28:0xfffffe0097a12bc0
code segment            = base 0x0, limit 0xfffff, type 0x1b
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = processor eflags       = interrupt enabled, interrupt enabled, resume, resume, IOPL = 0
IOPL = 0
current process         = current process        = 0 (system_taskq_1) 1198 (zpool)
trap number             = 18
tpanic: integer divide fault
cpuid = 0
KDB: stack backtrace:
#0 0xffffffff80910f30 at kdb_backtrace+0x60
#1 0xffffffff808d6645 at panic+0x155
#2 0xffffffff80cc9a9f at trap_fatal+0x38f
#3 0xffffffff80cc96fc at trap+0x72c
#4 0xffffffff80cb04f2 at calltrap+0x8
#5 0xffffffff81a8c4e6 at vdev_mirror_io_start+0x146
#6 0xffffffff81aa7205 at zio_vdev_io_start+0x185
#7 0xffffffff81aa4352 at zio_execute+0x162
#8 0xffffffff81a2f83d at arc_read+0x87d
#9 0xffffffff81a4917e at traverse_prefetcher+0x13e
#10 0xffffffff81a48580 at traverse_visitbp+0x270
#11 0xffffffff81a48749 at traverse_visitbp+0x439
#12 0xffffffff81a48fa3 at traverse_dnode+0x83
#13 0xffffffff81a48d45 at traverse_visitbp+0xa35
#14 0xffffffff81a48749 at traverse_visitbp+0x439
#15 0xffffffff81a48fa3 at traverse_dnode+0x83
#16 0xffffffff81a48a0c at traverse_visitbp+0x6fc
#17 0xffffffff81a482b6 at traverse_prefetch_thread+0x96

I've downloaded latest snapshot of 10-STABLE, booted it and ran

~ # zpool import -fR /mnt zroot

The error was same.
>How-To-Repeat:

>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: