From owner-freebsd-current@FreeBSD.ORG Mon Feb 16 11:51:04 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3D41316A4CE for ; Mon, 16 Feb 2004 11:51:04 -0800 (PST) Received: from arginine.spc.org (arginine.spc.org [195.206.69.236]) by mx1.FreeBSD.org (Postfix) with ESMTP id 11F0743D1F for ; Mon, 16 Feb 2004 11:51:04 -0800 (PST) (envelope-from bms@spc.org) Received: from localhost (localhost [127.0.0.1]) by arginine.spc.org (Postfix) with ESMTP id 193AF6520C for ; Mon, 16 Feb 2004 19:51:03 +0000 (GMT) Received: from arginine.spc.org ([127.0.0.1]) by localhost (arginine.spc.org [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 20939-02-5 for ; Mon, 16 Feb 2004 19:51:02 +0000 (GMT) Received: from saboteur.dek.spc.org (82-147-17-88.dsl.uk.rapidplay.com [82.147.17.88]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by arginine.spc.org (Postfix) with ESMTP id 93792651EE for ; Mon, 16 Feb 2004 19:51:02 +0000 (GMT) Received: by saboteur.dek.spc.org (Postfix, from userid 1001) id 773DF14; Mon, 16 Feb 2004 19:51:01 +0000 (GMT) Date: Mon, 16 Feb 2004 19:51:01 +0000 From: Bruce M Simpson To: freebsd-current@freebsd.org Message-ID: <20040216195101.GB3791@saboteur.dek.spc.org> Mail-Followup-To: freebsd-current@freebsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: remote gdb (and firewire/dcons) not functioning as expected X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 Feb 2004 19:51:04 -0000 Hi, I'm trying to debug the problem introduced by the earlier commit to remove mbufs from the stag (MT_TAG) over the weekend. First of all, I tried to use dconschat to open a connection to the GDB port over firewire. This didn't work. dconschat complained it couldn't find the CROM entry on the system under test. Manual inspection of the CROM entries via fwcontrol(8) revealed that it was indeed present, and the EUI64 was typed correctly. Now, when I try to use 9600 baud serial (over COM1 on both machines) as a fallback, I get the following results (after earlier being able to set a breakpoint in ip_output() before the box went multiuser):- (kgdb) target remote /dev/cuaa0 Remote debugging using /dev/cuaa0 0xc0522d81 in ip_output (m=0xc10ecf, opt=0x0, ro=0x0, flags=0, imo=0x68000000, inp=0x38c28d01) at ../../../netinet/ip_output.c:139 139 int hlen = sizeof (struct ip); warning: Unable to find dynamic linker breakpoint function. GDB will be unable to debug shared library initializers and track explicitly loaded dynamic code. warning: shared library handler failed to enable breakpoint (kgdb) step Can't send signals to this remote system. SIGSEGV not sent. Program received signal SIGSEGV, Segmentation fault. 0xc0522d81 in ip_output (m=0xc10ecf, opt=0x0, ro=0x0, flags=0, imo=0x68000000, inp=0x38c28d01) at ../../../netinet/ip_output.c:139 139 int hlen = sizeof (struct ip); (kgdb) The target system and my laptop (where I run gdb) are both seeing the same kernel image, which I NFS-mount from my build server. All boxes are running fresh -CURRENT from Saturday. Any ideas? This is most perplexing... BMS