From owner-freebsd-hackers Fri Feb 27 18:16:37 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id SAA23629 for freebsd-hackers-outgoing; Fri, 27 Feb 1998 18:16:37 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from dingo.cdrom.com (dingo.cdrom.com [204.216.28.145]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id SAA23624 for ; Fri, 27 Feb 1998 18:16:30 -0800 (PST) (envelope-from mike@dingo.cdrom.com) Received: from dingo.cdrom.com (localhost [127.0.0.1]) by dingo.cdrom.com (8.8.8/8.8.5) with ESMTP id SAA00165; Fri, 27 Feb 1998 18:14:03 -0800 (PST) Message-Id: <199802280214.SAA00165@dingo.cdrom.com> X-Mailer: exmh version 2.0zeta 7/24/97 To: Greg Lehey cc: Mike Smith , FreeBSD Hackers Subject: Re: Kernel debugging: what's going on here? In-reply-to: Your message of "Sat, 28 Feb 1998 12:32:53 +1030." <19980228123253.24049@freebie.lemis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 27 Feb 1998 18:14:02 -0800 From: Mike Smith Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > 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? And more importantly, that bp->b_vp is expected to be the same type? (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. -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message