gdbserver
gdbserver is a computer program that makes it possible to remotely debug other programs.[1] Running on the same system as the program to be debugged, it allows the GNU Debugger to connect from another system; that is, only the executable to be debugged needs to be resident on the target system ("target"), while the source code and a copy of the binary file to be debugged reside on the developer’s local computer ("host"). The connection can be either TCP or a serial line.
How it works
gdbserver
is launched on the target system, with the arguments:- Either a device name (to use a serial line) or a TCP hostname and portnumber, and
- The path and filename of the executable to be debugged
- It then waits passively for the host gdb to communicate with it.
gdb
is run on the host, with the arguments:- The path and filename of the executable (and any sources) on the host, and
- A device name (for a serial line) or the IP address and port number needed for connection to the target system.
Example for debugging a program called hello_world
on a remote target using TCP ("2159" is the registered TCP port number for remote GDB):
remote@~$ gdbserver :2159 hello_world
Process hello_world created; pid = 2509
Listening on port 2159
local@~$ gdb -q hello_world
Reading symbols from /home/user/hello_world...done.
(gdb) target remote 192.168.0.11:2159
Remote debugging using 192.168.0.11:2159
0x002f3850 in ?? () from /lib/ld-linux.so.2
(gdb) continue
Continuing.
Program received signal SIGSEGV, Segmentation fault.
0x08048414 in main () at hello_world.c:10
10 printf("x[%d] = %g\n", i, x[i]);
(gdb)
Alternatives
Another technique for debugging programs remotely is to use a remote stub.[2] In this case, the program to be debugged is linked with a few special-purpose subroutines that implement the GDB remote serial protocol. The file containing these subroutines is called a "debugging stub".
See also
Notes
References
- Andreas Zeller: Why Programs Fail: A Guide to Systematic Debugging, Morgan Kaufmann, 2005. ISBN 1-55860-866-4