Subject: kern/17794: panic unplugging umass device
To: None <>
From: None <>
List: netbsd-bugs
Date: 08/01/2002 11:28:14
>Number:         17794
>Category:       kern
>Synopsis:       panic unplugging umass device
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Aug 01 02:29:01 PDT 2002
>Originator:     Alan Barrett
>Release:        NetBSD 1.6D
Not much
System: NetBSD 1.6D
Architecture: i386
Machine: i386
I plugged a digital camera into a USB port on an i386 machine.  The
kernel attached the umass0 device as expected.  (Unfortunately, the
kernel config did not include "wd* at umass?", so I was unable to access
the file system in the camera.)

I then unplugged the USB cable, and the machine paniced.

Manually transcribed messages:

umass0: at uhub0 port 2 (addr 2) disconnected
panic: kernel diagnostic assertion "umap->refcount != 0" failed: file "/usr/src/sys/uvm/uvm_bio.c", line 253
stopped in pid 4 (usb0) at cpu_Debugger+0x4: Leave
db> c
syncing disks... Data modified on free list: word 4 of object 0xc0be5b00 size 84
previous type UVM amap (0xdead01ef != 0xdeadbeef)

Connect a digital camera (umass device) to a USB port, and then
disconnect it.  (The camera was a Panasonic NV-DS88 with a 64MB SD card,
in case that matters.)