NEW-UI using MI2 in GDB missing ?

[qrkyckling]

I know there was a restructure of the debugging code some time ago and since then I have not been able to find how to connect to an existing session using MI2.

Was a great thing to have when you started a GDB session on your binary and then realized you actually wanted to bring it into Ghidra after some successful event.

Was this option removed or renamed and I missed it ?

EDIT:
To clarify. The option is not missing from GDB but I can't find the option to connect to existing session over MI2 in Ghidra since version 11.3 or so.

[nsadeveloper789]

The MI2 stuff was removed, but the use case is still possible.

Setup

If you have not already done so, you'll want to pip install our ghidragdb package. In normal operation, we just point your PYTHONPATH to the source code in a Ghidra installation, but if you're running gdb outside of Ghidra, it's just easier to install the package. Supposing you are using Ghidra 11.4.x:

pip install ghidragdb==11.4

Then, start gdb outside of Ghidra and type:

python import ghidragdb

If that works, you're all set up! Move on to Use below.

Otherwise, you may need to check what version of Python is embedded in gdb, and retry using something like:

python3.12 -m pip install ghidragdb==11.4

A sort of clever way to accomplish this automatically is to use Ghidra's gdb via ssh connector to localhost. It'll figure the version stuff out and prompt you to install the package automatically. Once that works, try the python import line above in gdb again.

Use

1. In Ghidra's Connections window, click Accept a single inbound TCP connection in the local toolbar.
2. Click Listen, and then take note of the acceptor's port number in the Connections window, e.g., 12345.
3. From within your existing gdb session that you'd like to join into Ghidra:

   python import ghidragdb
   ghidra trace connect localhost:12345
   ghidra trace start
   ghidra trace sync-enable
   

4. Because you've already got a running target (presumably), you may want to add:

   ghidra trace sync-synth-stopped
   

   Or just step once.

A good bit of background and troubleshooting in https://github.com/NationalSecurityAgency/ghidra/blob/master/GhidraDocs/GhidraClass/Debugger/B1-RemoteTargets.md is applicable here, even though your use case is not exactly the same.