Linux – Remote debug error with GDB

debugginggdblinuxvirtual machine

I tried to remote debug an 32-bit application on x86_64 suse linux, but get this "remote register badly formatted" error.

I start up the gdbserver as listening on port 12345 (gdbserver localhost:12345 my_prog)

And this is the error:

$ gdb
GNU gdb 6.6
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "x86_64-suse-linux".
(gdb) target remote <ip>:12345
Remote debugging using <ip>:12345
Remote register badly formatted: T0506:0000000000000000;07:80b8bcff00000000;10:4028f0f700000000;
here: 0000000;07:80b8bcff00000000;10:4028f0f700000000;
(gdb)

This is the debug server machine (uname -a):

Linux server 2.6.16.60-0.31-smp #1 SMP Tue Oct 7 16:16:29 UTC 2008 x86_64 x86_64 x86_64 GNU/Linux

And this is the debug client machine (uname -a):

Linux client 2.6.16.54-0.2.5-default #1 Mon Jan 21 13:29:51 UTC 2008 x86_64 x86_64 x86_64 GNU/Linux

Both machines are running in virtual machines though (VMWare). The gdbserver binary is copied from the client machine to the server machine.

(I remote debug because the runtime environment on the debug server is production-like, and doesn't contain any development tools, access to the source code etc.)

Any suggestions are welcome.

UPDATE: this worked for me by issuing the following command in gdb:

set architecture i386:x86-64

Best Answer

Perhaps you need to execute something like set architecture i386 at the (gdb) prompt? What does show architecture say after you connect to the remote target?