From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14762 invoked by alias); 19 May 2005 00:26:50 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 14546 invoked from network); 19 May 2005 00:26:34 -0000 Received: from unknown (HELO linda-5.paradise.net.nz) (202.0.58.24) by sourceware.org with SMTP; 19 May 2005 00:26:34 -0000 Received: from smtp-2.paradise.net.nz (smtp-2b.paradise.net.nz [202.0.32.211]) by linda-5.paradise.net.nz (Paradise.net.nz) with ESMTP id <0IGP001BFNW9P5@linda-5.paradise.net.nz> for gdb@sources.redhat.com; Thu, 19 May 2005 12:26:33 +1200 (NZST) Received: from dodo (202-0-52-96.cable.paradise.net.nz [202.0.52.96]) by smtp-2.paradise.net.nz (Postfix) with ESMTP id B94829E2BB for ; Thu, 19 May 2005 12:26:33 +1200 (NZST) Date: Thu, 19 May 2005 00:26:00 -0000 From: David Antliff Subject: remote debugging symbol problem X-X-Sender: david@localhost To: gdb@sources.redhat.com Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; format=flowed; charset=US-ASCII X-SW-Source: 2005-05/txt/msg00179.txt.bz2 Hello, We use gdb-6.0 and a PowerPC port of gdbserver to remotely debug our target application on it's PowerPC platform. Our application forks several (20 or so) child processes shortly after starting up, and a few of these child processes create threads. Until quite recently, this has all worked fine. I was able to invoke: # gdbserver 0.0.0.0:2345 --attach for any of the child processes, and then run on my development host (x86 linux): $ cd $ gdb I am 100% sure the same application binary is running on the host as on the target (I'm using NFS). Normally, once GDB is pointed at the target, the process is interrupted and GDB can show a stack trace at the point of interruption. However, now, I just get this: (gdb) target remote 10.16.10.237:2345 Remote debugging using 10.16.10.237:2345 0x0fe896a0 in ?? () warning: Unable to find dynamic linker breakpoint function. GDB will be unable to debug shared library initializers and track explicitly loaded dynamic code. My understanding is that the warning is simply because the standard libraries aren't compiled with GDB support. This used to happen even when it worked so I'm not concerned about it (should I be?). That address 0x0fe896a0 is always the same regardless of which child process I attach to. There is no backtrace available (just prints out that address and ?? again). I used the info commands to check the symbol table is correct, and it is. Also: (gdb) info target Symbols from "". Remote serial target in gdb-specific protocol: Debugging a target over a serial line. While running this, GDB does not access memory from... Local exec file: `/', file type elf32-powerpc. Entry point: 0x10002aa8 0x10000114 - 0x10000121 is .interp 0x10000130 - 0x10000150 is .note.ABI-tag 0x10000150 - 0x1000081c is .hash 0x1000081c - 0x100016dc is .dynsym 0x100016dc - 0x10001ec9 is .dynstr 0x10001eca - 0x100020a2 is .gnu.version 0x100020a4 - 0x10002144 is .gnu.version_r 0x10002144 - 0x10002174 is .rela.sbss 0x10002174 - 0x10002a80 is .rela.plt 0x10002a80 - 0x10002aa8 is .init 0x10002aa8 - 0x1014ba9c is .text 0x1014ba9c - 0x1014babc is .fini 0x1014bac0 - 0x101be660 is .rodata 0x101ce660 - 0x102172bc is .data 0x102172bc - 0x102172c0 is .eh_frame 0x102172c0 - 0x102172d8 is .got2 0x102172d8 - 0x102172e0 is .ctors 0x102172e0 - 0x102172e8 is .dtors 0x102172e8 - 0x102172f8 is .got 0x102172f8 - 0x102173b8 is .dynamic 0x102173b8 - 0x10217dac is .sdata 0x10217db0 - 0x10218308 is .sbss 0x10218308 - 0x10218c5c is .plt 0x10218c60 - 0x104d4660 is .bss 'info sources' and 'info functions' show the expected output. I've spent a few hours reading the GDB manual but I cannot find any clues as to why this is happening. If I write a short main() loop and try remotely debugging that, it works fine. I have disabled all optimisations, and gcc is using -g3 (I've tried just -g as well). Does anyone have any ideas for further things I could try please? What sort of things that can go wrong would cause this sort of problem or these symptoms? Kind regards, David Antliff NZ