From owner-freebsd-hackers Mon Mar 2 13:42:38 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id NAA20127 for freebsd-hackers-outgoing; Mon, 2 Mar 1998 13:42:38 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id NAA20110 for ; Mon, 2 Mar 1998 13:42:29 -0800 (PST) (envelope-from grog@lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.8.7/8.8.5) with ESMTP id IAA08730; Tue, 3 Mar 1998 08:12:18 +1030 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.8.8/8.8.7) id IAA12988; Tue, 3 Mar 1998 08:12:18 +1030 (CST) (envelope-from grog) Message-ID: <19980303081217.61608@freebie.lemis.com> Date: Tue, 3 Mar 1998 08:12:17 +1030 From: Greg Lehey To: Julian Elischer Cc: Mike Smith , FreeBSD Hackers Subject: Re: Kernel debugging: what's going on here? References: <19980228123253.24049@freebie.lemis.com> <199802280214.SAA00165@dingo.cdrom.com> <19980228124844.00033@freebie.lemis.com> <34FAFF9C.59E2B600@whistle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.89i In-Reply-To: <34FAFF9C.59E2B600@whistle.com>; from Julian Elischer on Mon, Mar 02, 1998 at 10:51:08AM -0800 WWW-Home-Page: http://www.lemis.com/~grog Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Mon, 2 March 1998 at 10:51:08 -0800, Julian Elischer wrote: > Greg Lehey wrote: >> >> 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. > > Ah struct vnode changed recently... Right. > didi you do a 'make depend' ? > > bet it didn't recompile some source... Worse. I found the @ directory pointing into the wrong tree. Logical, once you uknow where to look, but I was really beginning to suspect gdb. Greg To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message