From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266204AbUAQTzQ (ORCPT ); Sat, 17 Jan 2004 14:55:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266205AbUAQTzP (ORCPT ); Sat, 17 Jan 2004 14:55:15 -0500 Received: from gateway-1237.mvista.com ([12.44.186.158]:41463 "EHLO av.mvista.com") by vger.kernel.org with ESMTP id S266204AbUAQTzG (ORCPT ); Sat, 17 Jan 2004 14:55:06 -0500 Message-ID: <40099301.6000202@mvista.com> Date: Sat, 17 Jan 2004 11:54:41 -0800 From: George Anzinger Organization: MontaVista Software User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2) Gecko/20021202 X-Accept-Language: en-us, en MIME-Version: 1.0 To: "Amit S. Kale" CC: Pavel Machek , Linux Kernel , KGDB bugreports , Matt Mackall , discuss@x86-64.org Subject: Re: KGDB 2.0.3 with fixes and development in ethernet interface References: <200401161759.59098.amitkale@emsyssoft.com> <20040116215144.GA208@elf.ucw.cz> <40088E9D.1010908@mvista.com> <200401171459.01794.amitkale@emsyssoft.com> In-Reply-To: <200401171459.01794.amitkale@emsyssoft.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Amit S. Kale wrote: > 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. I don't seem to have such a problem with the mm kgdb. No kern_schedule there... -- George Anzinger george@mvista.com High-res-timers: http://sourceforge.net/projects/high-res-timers/ Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml