[prev in list] [next in list] [prev in thread] [next in thread] 

List:       freebsd-hackers
Subject:    Re: Kernel debugging: what's going on here?
From:       Greg Lehey <grog () lemis ! com>
Date:       1998-02-28 2:30:44
[Download RAW message or body]

On Fri, 27 February 1998 at 18:14:02 -0800, Mike Smith wrote:
>> On Fri, 27 February 1998 at 17:56:46 -0800, Mike Smith wrote:
>>> Yes, I noticed.  But rewriting the bp on the fly is not uncommon; quite
>>> a few device drivers do it, it wouldn't surprise me if it wasn't done
>>> elsewhere rather than cloning the original.
>>
>> Sure, all sorts of things modify the buffer header.  But you're still
>> missing the point: the processor is stopped here, it's in the
>> debugger.  No instructions were executed between the two views.  You
>> might just as well take a look at a dump.  Since when does the content
>> of memory differ depending on where you look at it from?
>
> Whoops.  OK, are we sure that "bp" points to the same type in both
> cases?

Not any more :-)  Somebody else replied first.

> And more importantly, that bp->b_vp is expected to be the same type?

Yes, it was.

> (Yes, this is *really* clutching at straws).  There's not much else
> short of a GDB bug that I can think of that would cause this.

Thanks.  I should have seen this myself, but sometimes you end up
looking in the wrong place.

Greg

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message

[prev in list] [next in list] [prev in thread] [next in thread]