From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265700AbUAQJ3j (ORCPT ); Sat, 17 Jan 2004 04:29:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265996AbUAQJ3j (ORCPT ); Sat, 17 Jan 2004 04:29:39 -0500 Received: from svr44.ehostpros.com ([66.98.192.92]:45481 "EHLO svr44.ehostpros.com") by vger.kernel.org with ESMTP id S265700AbUAQJ3i (ORCPT ); Sat, 17 Jan 2004 04:29:38 -0500 From: "Amit S. Kale" Organization: EmSysSoft To: George Anzinger Subject: Re: KGDB 2.0.3 with fixes and development in ethernet interface Date: Sat, 17 Jan 2004 14:59:01 +0530 User-Agent: KMail/1.5 Cc: Pavel Machek , Linux Kernel , KGDB bugreports , Matt Mackall , discuss@x86-64.org References: <200401161759.59098.amitkale@emsyssoft.com> <20040116215144.GA208@elf.ucw.cz> <40088E9D.1010908@mvista.com> In-Reply-To: <40088E9D.1010908@mvista.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200401171459.01794.amitkale@emsyssoft.com> X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - svr44.ehostpros.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - emsyssoft.com Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Saturday 17 Jan 2004 6:53 am, George Anzinger wrote: > Pavel Machek wrote: > > Hi! > > > >>KGDB 2.0.3 is available at > >>http://kgdb.sourceforge.net/kgdb-2/linux-2.6.1-kgdb-2.0.3.tar.bz2 > >> > >>Ethernet interface still doesn't work. It responds to gdb for a couple of > >>packets and then panics. gdb log for ethernet interface is pasted below. > >> > >>It panics and enter kgdb_handle_exception recursively and silently. To > >> see the panic on screen make kgdb_handle_exception return immediately if > >> kgdb_connected is non-zero. > >> > >>Panic trace is pasted below. It panics in skb_release_data. Looks like > >> skb handling will have to changed to be have kgdb specific buffers. > > > > This seems to be needed (if I unselect CONFIG_KGDB_THREAD, I get > > compile error on x86-64). > > Amit, could you explain why this is an option? It seems very useful and > not really too much code... It saves all registers before switch_to. It does that two times at present. Once (implicit) register save by gcc and an explicit register save in arch//kernel/entry.S Second register save in kern_schedule generates a pt_regs structure which gdb can get all registers at once from. If it's omited, gdb has to figure out where gcc has saved registers from the non-standards code in switch_to, which it can't do correctly all the time. We can have a check for (a new variable) debugger_enabled before calling kern_schedule. That'll be add negligible overhead and will allow extra thread info to be saved only when a debugger is enabled. There will not be any need for CONFIG_KGDB_THREAD also. -- Amit Kale EmSysSoft (http://www.emsyssoft.com) KGDB: Linux Kernel Source Level Debugger (http://kgdb.sourceforge.net)