On 13-Apr-2002 Will Andrews wrote:
> On Sat, Apr 13, 2002 at 12:44:36PM -0400, John Baldwin wrote:
>> Can you get a backtrace in ddb?  It looks like a null pointer dereference,
>> and
>> knowing where it happened would help.  Finding the file and line of the
>> instruction pointer using addr2line on kernel.debug would be helpful as
>> well.
> It *is* a null pointer deref.  Joe and I looked at this problem,
> and it seems a function called device_get_ivars() isn't doing
> its job in sys/dev/usb/usb_port.h.  So the variable is getting
> filled with a NULL pointer for the iface element and is later
> deref'd.  That's the limit of my debugging, and Joe is looking
> into the problem actively.

Well, if device_get_ivars() is returning a NULL pointer, then it probably
means its parent bus device isn't setting up the ivars for the child
device properly.  As far as I understand, you can think of ivars as being
per-device variables or state often used by a parent bus to set
bus-specific information for a child device.


John Baldwin <[EMAIL PROTECTED]>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve!"  -  http://www.FreeBSD.org/

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