Launch a GDB server with the specified command line, and launches GDB to attach to it.

args (list) – Arguments to the process, similar to process.

gdbscript (str) – GDB script to run.

exe (str) – Path to the executable on disk

env (dict) – Environment to start the binary in

ssh (ssh) – Remote ssh session to use to launch the process.

sysroot (str) – Set an alternate system root. The system root is used to load absolute shared library symbol files. This is useful to instruct gdb to load a local version of binaries/libraries instead of downloading them from the gdbserver, which is faster

api (bool) – Enable access to GDB Python API.

process or ssh_channel – A tube connected to the target process. When api=True, gdb member of the returned object contains a Gdb instance.

Notes

The debugger is attached automatically, and you can debug everything from the very beginning. This requires that both gdb and gdbserver are installed on your machine.

When GDB opens via debug(), it will initially be stopped on the very first instruction of the dynamic linker (ld.so) for dynamically-linked binaries.

Only the target binary and the linker will be loaded in memory, so you cannot set breakpoints on shared library routines like malloc since libc.so has not even been loaded yet.

There are several ways to handle this:

This is only invoked after all of the required shared libraries are loaded.

You can generally get the address via the GDB command info file.

This has the side-effect of setting breakpoints for every function which matches the name. For malloc, this will generally set a breakpoint in the executable’s PLT, in the linker’s internal malloc, and eventaully in libc’s malloc.

There is no way to stop on any specific library being loaded, and sometimes multiple libraries are loaded and only a single breakpoint is issued.

Generally, you just add a few continue commands until things are set up the way you want it to be.

Examples

Create a new process, and stop it at ‘main’

Send a command to Bash

Interact with the process

Create a new process, and stop it at ‘_start’

Send a command to Bash

Interact with the process

Using GDB Python API:

Using SSH:

You can use debug() to spawn new processes on remote machines as well, by using the ssh= keyword to pass in your ssh instance.

Connect to the SSH server and start a process on the server

Send a command to Bash

Interact with the process >>> io.interactive() # doctest: +SKIP >>> io.close()