lebr0nli/GEP

gdb doesn't import prompt_toolkit from $HOME/GEP/

dp12 opened this issue · 3 comments

dp12 commented

This is a really cool plugin and I'm eager to use its features. However, when I try to load it with source ~/GEP/.gdbinit-gep.py, I get an error about "'_GdbOutputFile' object has no attribute 'fileno'". It looks like there's some issue with prompt_toolkit. To get a full backtrace, I did the following:

(gdb) python
>from prompt_toolkit import PromptSession
>p = PromptSession()
>end
Traceback (most recent call last):
  File "<string>", line 2, in <module>
  File "/home/dp12/.local/lib/python3.8/site-packages/prompt_toolkit/shortcuts/prompt.py", line 468, in __init__
    self.app = self._create_application(editing_mode, erase_when_done)
  File "/home/dp12/.local/lib/python3.8/site-packages/prompt_toolkit/shortcuts/prompt.py", line 719, in _create_application
    application: Application[_T] = Application(
  File "/home/dp12/.local/lib/python3.8/site-packages/prompt_toolkit/application/application.py", line 277, in __init__
    self.output = output or session.output
  File "/home/dp12/.local/lib/python3.8/site-packages/prompt_toolkit/application/current.py", line 70, in output
    self._output = create_output()
  File "/home/dp12/.local/lib/python3.8/site-packages/prompt_toolkit/output/defaults.py", line 77, in create_output
    return Vt100_Output.from_pty(
  File "/home/dp12/.local/lib/python3.8/site-packages/prompt_toolkit/output/vt100.py", line 466, in from_pty
    fd = stdout.fileno()
AttributeError: '_GdbOutputFile' object has no attribute 'fileno'
Error while executing Python code.

Any ideas about what might be happening?

lebr0nli commented

Hi, can you provide more information about the version of your gdb, Python, and prompt_toolkit?

By the way, this plugin only works with prompt_toolkit 2 now, so please ensure that you run pip install --target="$HOME/GEP/" prompt_toolkit==2.0.10 before using GEP.

  • 👍1
dp12 commented

Thanks for the quick reply @lebr0nli! I guess I created the issue too soon. The fix was quick, but posting what I did for future users who run into this problem:

I tested what version of prompt_tookit I had installed by running the following in gdb:

pwndbg> python
>import prompt_toolkit
>print(prompt_toolkit.__version__)
>end
3.0.18

Of course, prompt_toolkit 3 won't work with this plugin.
Even doing python -m pip install -Iv --target="$HOME/GEP/" prompt_toolkit==2.0.10 didn't seem to fix the issue; gdb stubbornly refused to use prompt_toolkit 2, so I had to uninstall the old prompt toolkit:

python -m pip uninstall prompt_toolkit

Then I re-ran the pip install of prompt_tookit 2 and everything started working.

lebr0nli commented

I think my import mechanism go wrong so even doing pip install --target="$HOME/GEP/" prompt_toolkit==2.0.10 didn't seem to fix the issue, I will try to fix this problem to let everyone who using prompt_toolkit 3 can use GEP without uninstalling it.

Thanks for the bug!