From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30744 invoked by alias); 28 Dec 2009 07:37:08 -0000 Received: (qmail 30736 invoked by uid 22791); 28 Dec 2009 07:37:07 -0000 X-SWARE-Spam-Status: No, hits=-1.7 required=5.0 tests=AWL,BAYES_00,SARE_MSGID_LONG40,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mail-pw0-f49.google.com (HELO mail-pw0-f49.google.com) (209.85.160.49) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 28 Dec 2009 07:37:03 +0000 Received: by pwj12 with SMTP id 12so7194738pwj.8 for ; Sun, 27 Dec 2009 23:37:02 -0800 (PST) MIME-Version: 1.0 Received: by 10.142.121.3 with SMTP id t3mr1334787wfc.246.1261985822069; Sun, 27 Dec 2009 23:37:02 -0800 (PST) In-Reply-To: <4B385274.1000100@analog.com> References: <8ac60eac0912260055o2d6bcb6cld7f8830e947cdd7@mail.gmail.com> <8ac60eac0912261936q49f50cf6ofabf2c56055621af@mail.gmail.com> <4B381A0F.70803@analog.com> <4B383264.30604@analog.com> <4B385274.1000100@analog.com> From: Hui Zhu Date: Mon, 28 Dec 2009 07:37:00 -0000 Message-ID: Subject: Re: gdb symbol problem To: Hushan Jia Cc: Paul Pluzhnikov , gdb@sourceware.org, Jie Zhang Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2009-12/txt/msg00169.txt.bz2 Maybe your address is a part of a LKM. If so, find it out with "cat /proc/modules", and use gdb cmd "add-symbol-file module_dir_name address" add symbol message to gdb. Hui On Mon, Dec 28, 2009 at 14:38, Jie Zhang wrote: > On 12/28/2009 01:09 PM, Hushan Jia wrote: >> >> On Mon, Dec 28, 2009 at 12:21 PM, Jie Zhang =A0wro= te: >>> >>> On 12/28/2009 12:14 PM, Hushan Jia wrote: >>>> >>>> On Mon, Dec 28, 2009 at 10:38 AM, Jie Zhang >>>> =A0wrote: >>>>> >>>>> On 12/27/2009 11:45 AM, Hushan Jia wrote: >>>>>> >>>>>> On Sun, Dec 27, 2009 at 11:36 AM, Paul Pluzhnikov >>>>>> =A0 =A0 =A0wrote: >>>>>>> >>>>>>> On Sat, Dec 26, 2009 at 6:16 PM, Hushan Jia >>>>>>> =A0wrote: >>>>>>> >>>>>>>> I invoke gdb like this: >>>>>>>> >>>>>>>> [hushan@hushan-t linux-2.6.31.3]$ gdb ./vmlinux >>>>>>> >>>>>>> Oh, you are not debugging a regular application. You probably should >>>>>>> have mentioned that in your initial message. >>>>>> >>>>>> Sorry for forget the important information. >>>>>> >>>>> What's the output of "readelf -S vmlinux"? >>>> >>>> Hi, The output is: >>>> >>>> # readelf -S vmlinux >>>> There are 77 section headers, starting at offset 0x3b569cc: >>>> >>>> Section Headers: >>>> =A0 [Nr] Name =A0 =A0 =A0 =A0 =A0 =A0 =A0Type =A0 =A0 =A0 =A0 =A0 =A0A= ddr =A0 =A0 Off =A0 =A0Size =A0 ES Flg >>>> Lk >>>> Inf Al >>>> =A0 [ 0] =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 NULL =A0 =A0 =A0 =A0 =A0 = =A000000000 000000 000000 00 >>>> =A00 >>>> =A0 0 =A00 >>>> =A0 [ 1] .text.head =A0 =A0 =A0 =A0PROGBITS =A0 =A0 =A0 =A0c1000000 00= 1000 0000a9 00 =A0AX >>>> =A00 >>>> =A0 0 =A04 >>>> =A0 [ 2] .rel.text.head =A0 =A0REL =A0 =A0 =A0 =A0 =A0 =A0 00000000 3b= 575d4 000070 08 >>>> =A075 =A0 1 =A04 >>>> =A0 [ 3] .text =A0 =A0 =A0 =A0 =A0 =A0 PROGBITS =A0 =A0 =A0 =A0c10000c= 0 0010c0 291284 00 =A0AX >>>> =A00 >>>> =A0 0 32 >>> >>> It seems the machine was not executing code of your vmlinux. The code in >>> your vmlinux starts from 0xc1000000. But when you connected with GDB, t= he >>> stopped PC was 0xc0467118, which was just ahead of code sections of your >>> vmlinux. Is it possbile the linux kernel running in your qemu was not t= he >>> one you told GDB? >> >> Hi, I compiled the kernel on the host machine, and then copy kernel >> and modules files to the qemu virtual machine, they are the same >> files. > > OK. Then you need to find out what's at the address 0xc0467118. GDB cannot > show you the symbol and source line which it doesn't know. /proc/kallsyms > might be helpful if that address is in kernel. > >> and the kgdb seems does not work, if I run c in gdb, then I cannot >> interrupt it using CTRL-C, and the breakpoints are never hit. >> The attached file is the kernel config, and kernel is >> linux-2.6.31.3.tar.bz2, downloaded from kernel.org. >> > I have no idea about kgdb. > > > Jie >