kern/71791: Fatal trap 12: page fault while in kernel mode

[Claudio Destro]

>Number:         71791
>Category:       kern
>Synopsis:       Fatal trap 12: page fault while in kernel mode
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Sep 16 11:40:25 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator:     Claudio Destro
>Release:        FreeBSD 5.3-BETA4 i386
>Organization:
>Environment:
>Description:
I receive a fatal trap 12 *every* time I disconnect my usb mass storage.

Inserting is ok:
..
uhub1: Sony USB Embedded Hub, class 9/0, rev. 2.00/0.01, addr3
uhub1: 1 port with 0 removable, self powered
umass0: Sony USB Mass Storage Denic, rev 2.00/0.01, addr 4
da1: at umass-sim0 bus 0 target 0 lun 0
da1: <Sony Storage Media 1.00> Removable Direct Access SCSI-0 device
da1: 1.000MB/s transfers
da1: 125MB (256000 512 bytes sectors; 64H 32/T 125LI)
..

Removing results in a kernel panic:

uhub1: at ubhub0 port 1 (addr 3) disconnected
(da:umass-sim0:0:0:0): lost device
(da:umass-sim0:0:0:0): removing device entry
umass0: detached
(null): at uhub1 port 1 (addr 4) disconnected

Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0x400
fault code              = supervisor read, page not present
instruction pointer     = 0x84 0xc0690904
stack pointer           = 0x10 0xcc746bd4
frame pointer           = 0x10 0xcc746bf4
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         = 37 (usb0)
trap number             = 12
..

I dumped these info by hand this morning, but I think there are no errors...

hope this helps.
>How-To-Repeat:

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