persistent libc.txt.gz for glibc_function_args

[aliencaocao]

Is your feature request related to a problem? Please describe. Im always frustrated when I have to download https://www.gnu.org/software/libc/manual/text/libc.txt.gz everytime I work on a new project/switch to a different dir. I hope there can be a way to read the extracted json from a fixed path in env var.

Describe the solution you'd like Use the path defined in context.libc_args_path in gef config.

file libc.txt.gz cannot be found. download it from https://www.gnu.org/software/libc/manual/text/libc.txt.gz
Traceback (most recent call last):
  File "/root/.config/gef-extras/scripts/libc_function_args/tables/generate_glibc_args_json.py", line 56, in <module>
    fh = gzip.open(file_name, "r")
  File "/usr/lib/python3.10/gzip.py", line 58, in open
    binary_file = GzipFile(filename, gz_mode, compresslevel)
  File "/usr/lib/python3.10/gzip.py", line 174, in __init__
    fileobj = self.myfileobj = builtins.open(filename, mode or 'rb')
FileNotFoundError: [Errno 2] No such file or directory: 'libc.txt.gz'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/root/.config/gef-extras/scripts/libc_function_args/tables/generate_glibc_args_json.py", line 63, in <module>
    sys.exit(-1)
  File "/root/.gef-2024.01.py", line 446, in FakeExit
    raise RuntimeWarning
RuntimeWarning

[therealdreg]

the same bug: #107

@hugsy Is aware of the (bug) cause and is working on it

[aliencaocao]

Oh so this is supposed to be persistent but it is a bug that it is not?

[therealdreg]

The current code is not behaving as it should, so it is a bug.

As you can see, the libc and JSON files are already included, but it fails to find the path....

[therealdreg]

@aliencaocao can you test a simple crappy fix?

1

cd ~/.config/gef-extras/scripts/libc_function_args/tables
wget https://www.gnu.org/software/libc/manual/text/libc.txt.gz

2

Edit:

~/.config/gef-extras/scripts/libc_function_args/tables/generate_glibc_args_json.py

Replace:

file_name = "libc.txt.gz"

with this:

file_name = pathlib.Path(inspect.getfile(inspect.currentframe())).parent.resolve() / "libc.txt.gz"

Replace:

with open(outfile_name, "w") as outfile:

with this:

with open(pathlib.Path(inspect.getfile(inspect.currentframe())).parent.resolve() / outfile_name, "w") as outfile:

3

Edit:

~/.config/gef-extras/scripts/libc_function_args/__init__.py

Replace:

GLIBC_FUNCTION_ARGS_CURRENT_FILE = ...
GLIBC_FUNCTION_ARGS_CURRENT_DIRECTORY = ....

with this:

GLIBC_FUNCTION_ARGS_CURRENT_FILE = pathlib.Path(inspect.getfile(inspect.currentframe())).parent.resolve()
GLIBC_FUNCTION_ARGS_CURRENT_DIRECTORY = pathlib.Path(inspect.getfile(inspect.currentframe())).parent.resolve()

---

This works now as expected?

[aliencaocao]

I did the mods, launched gef once and saw the json written messages, then deleted the txt.gz, still same error come out. I should be expecting it to just read the existing json instead of trying to extract a new one right? The patches given does not seem to fix this for me as it still point to the txt.gz and does not check for any existing json.

[aliencaocao]

If I switch to the different dir without deleting the txt.gz, it works fine but it seem to be extracting it every time i run gef which is not very necessary. Also, when I run gef in tables, I get file x86_64.json exists, overwrite? [y/N] for both json.

[therealdreg]

Let's tackle this step by step.

First, I want to address the path issue, and then we'll move on to the other matters.

If we keep the files in the tables/ directory (json + tgz), everything works as you would expect, right?

(After fixing this, I'll look into ensuring that the JSON files aren't generated every time, etc.)

[DimSumCodes]

I was having a similar issue with the libc.txt.gz not being read from tables. I had no idea the cause, but using step 1 and 2 it fixed the issue and now properly recognizes the lic.txt.gz file in the tables directory. Also to note it does generate the x86_32 and x86_64 files in my directory every time I run gdb but it's not a big deal to me I just overwrite them every time and everything runs smooth. I did the other steps to see if it would resolve the overwrite json issue but unfortunately the json is another issue anyway.

[aliencaocao]

Yes it does work if i keep the txt.gz, but that was not the reason I opened the issue as I thought the json itself should be cached and reused. Seems like this is a feature request instead of a bug then

[therealdreg]

I have to download https://www.gnu.org/software/libc/manual/text/libc.txt.gz everytime I work on a new project/switch to a different dir

This should not happen, and this is my fix :D. So yes, this part is a bug!

[therealdreg]

I want to make sure everything works well.

Can you test the latest dev versions of gef-extras and gef and let me know if everything now works as you expect, please? @aliencaocao @DimSumCodes

• https://github.com/hugsy/gef-extras/archive/refs/heads/main.zip
• https://github.com/hugsy/gef/archive/refs/heads/main.zip

Related to: #109 #111 https://github.com/hugsy/gef/pull/1093

Can I close this issue?

[DimSumCodes]

Just checked it, works perfectly doesn't generate a new file in my active directory and doesn't have any issues referencing the files.

[aliencaocao]

Same for me.

[hugsy]

Great work on fixing this @therealdreg 🎉