From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25015 invoked by alias); 13 Jul 2002 22:24:29 -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 25008 invoked from network); 13 Jul 2002 22:24:28 -0000 Received: from unknown (HELO crack.them.org) (65.125.64.184) by sources.redhat.com with SMTP; 13 Jul 2002 22:24:28 -0000 Received: from drow by crack.them.org with local (Exim 3.12 #1 (Debian)) id 17TVJO-000859-00; Sat, 13 Jul 2002 17:24:22 -0500 Date: Sat, 13 Jul 2002 15:24:00 -0000 From: Daniel Jacobowitz To: Dan Kegel Cc: gdb@sources.redhat.com Subject: Re: Crash in gdbserver on ppc405 - what vintage of libthread_db is recommended? Message-ID: <20020713172422.A30747@crack.them.org> References: <3D30B11B.5070005@ixiacom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <3D30B11B.5070005@ixiacom.com>; from dkegel@ixiacom.com on Sat, Jul 13, 2002 at 04:00:43PM -0700 X-SW-Source: 2002-07/txt/msg00143.txt.bz2 I'll reiterate - I have about 99% confidence that your crash comes from mismatched host and target libraries. This is far and away the most frequent cause of problems, since libthread_db is not at all capable of handling errors in mismatched symbol lookup. I'm still trying to figure out ways to detect this. I'm almost leaning towards using libelf or a simple clone to take checksums of on-disk .text sections... On Sat, Jul 13, 2002 at 04:00:43PM -0700, Dan Kegel wrote: > I tried gdbserver on the ppc405 on a large multithreaded C++ program > compiled with g++3.0.2 or so. All I did was 'break main' > and 'cont', and gdbserver crashed. So I updated to last week's > snapshot (ftp://sources.redhat.com/pub/gdb/snapshots/current/gdb+dejagnu-weekly-CVS-20020709.tar.bz2), > built gdbserver for debugging, and reproduced the problem while debugging > gdbserver. Here's what popped up. Looks like the call to > td_ta_thr_iter is bombing. I'm using the libthread_db from Hard Hat 2.0, > dated about a year ago; perhaps I need to use a newer version? > Or is gdbserver itself misbehaving? > > Program received signal SIGSEGV, Segmentation fault. > 0x10008844 in linux_read_memory (memaddr=1275058749, myaddr=0x7fefeda8 "", > len=2094805880) at ../../../src/gdb/gdbserver/linux-low.c:1153 > 1153 = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); > (gdb) bt > #0 0x10008844 in linux_read_memory (memaddr=1275058749, myaddr=0x7fefeda8 "", > len=2094805880) at ../../../src/gdb/gdbserver/linux-low.c:1153 > #1 0x10005494 in read_inferior_memory (memaddr=1275058749, myaddr=0x7fefeda8 "", > len=2094805880) at ../../../src/gdb/gdbserver/target.c:63 > #2 0x10009740 in ps_pdread (ph=0x1001c850, addr=1275058749, buf=0x7fefeda8, > size=2094805880) at ../../../src/gdb/gdbserver/proc-service.c:112 > #3 0x0ffdd000 in td_thr_setgregs () from /lib/libthread_db.so.1 > #4 0x0ffdd1c4 in td_thr_tsd () from /lib/libthread_db.so.1 > #5 0x1000958c in thread_db_find_new_threads () > at ../../../src/gdb/gdbserver/thread-db.c:308 > #6 0x10009650 in thread_db_init () at ../../../src/gdb/gdbserver/thread-db.c:334 > #7 0x10008bb8 in linux_look_up_symbols () at ../../../src/gdb/gdbserver/linux-low.c:1226 > #8 0x10003ef4 in handle_query (own_buf=0x1001eee8 "qSymbol::") > at ../../../src/gdb/gdbserver/server.c:71 > #9 0x100042e8 in main (argc=3, argv=0x7ffffe84) > at ../../../src/gdb/gdbserver/server.c:192 > #10 0x0feb0dbc in ngettext () from /lib/libc.so.6 > (gdb) > -- Daniel Jacobowitz Debian GNU/Linux Developer MontaVista Software Carnegie Mellon University