From owner-freebsd-hackers Wed Aug 20 01:48:15 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id BAA09517 for hackers-outgoing; Wed, 20 Aug 1997 01:48:15 -0700 (PDT) Received: from nico.telstra.net (nico.telstra.net [139.130.204.16]) by hub.freebsd.org (8.8.5/8.8.5) with SMTP id BAA09512 for ; Wed, 20 Aug 1997 01:48:13 -0700 (PDT) Received: from freebie.lemis.com (gregl1.lnk.telstra.net [139.130.136.133]) by nico.telstra.net (8.6.10/8.6.10) with ESMTP id SAA08197; Wed, 20 Aug 1997 18:47:33 +1000 Received: (grog@localhost) by freebie.lemis.com (8.8.7/8.6.12) id SAA29741; Wed, 20 Aug 1997 18:17:31 +0930 (CST) Message-ID: <19970820181730.19951@lemis.com> Date: Wed, 20 Aug 1997 18:17:30 +0930 From: Greg Lehey To: Hans Zuidam Cc: hackers@FreeBSD.ORG Subject: Re: gdb: Program received signal SIGTRAP? References: <19970820122215.34114@lemis.com> <199708200732.JAA21257@truk.brandinnovators.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.81e In-Reply-To: <199708200732.JAA21257@truk.brandinnovators.com>; from Hans Zuidam on Wed, Aug 20, 1997 at 09:32:27AM +0200 Organisation: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8250 Fax: +61-8-8388-8250 Mobile: +61-41-739-7062 WWW-Home-Page: http://www.lemis.com/~grog Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Wed, Aug 20, 1997 at 09:32:27AM +0200, Hans Zuidam wrote: >> Greg Lehey wrote: >> Has anybody seen problems with gdb where you can't continue from a >> breakpoint? I'm currently trying to test user ppp, but once I hit a >> breakpoint, I can't continue. I'm running -current as of yesterday. >> Here's a sample: >> Program received signal SIGTRAP, Trace/breakpoint trap. >> DoLoop () at /src/FREEBIE/usr.sbin/ppp/main.c:773 >> 773 if (been_here_before) /* we won't be able to do it again, */ >> (gdb) >> Cannot insert breakpoint 0: >> Error accessing memory address 0xefbfdfdc: Bad address. > This is probably because your process (ppp) is corrupting its stack. > gdb examines to processes stack to find proper stack frames when > inserting/removing breakpoint. If the stack is corrupted gdb gets > very confused. Really? I can't recall seeing that. In any case, the process is not corrupting its stack. If I don't set the breakpoint, it runs fine. It could be that I've shot myself in the foot, though: I updated to -current of this morning, but didn't do a make world, though I did make gdb, so that's not the immediate problem. I'm doing a make world now, and will try again afterwards. Greg