Add port, gdb_args, and gdbserver_args to gdb.debug()
#2382
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+ port: specifies the port that should be used by the gdbserver (this is useful for alpine) + gdb_args: allows forwarding arguments to the gdb binary spawned by gdb.attach() (just a passthrough) aslo downgraded "GDB Python API is supported only for local processes" to a warning, because it seems to work on some systems.
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additionally added the optional argument |
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Cool, thank you! Allowing more control over the way debugging is initiated seems useful for one-off problems.
Your "plugin" looks nice, do you have plans to upstream features? I'd rather have nice docker and qemu integration than patchwork changes to make the external tool work. :D
pwnlib/gdb.py
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| @@ -612,7 +622,7 @@ def debug(args, gdbscript=None, exe=None, ssh=None, env=None, sysroot=None, api= | |||
| gdbscript = gdbscript or '' | |||
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| if api and runner is not tubes.process.process: | |||
| raise ValueError('GDB Python API is supported only for local processes') | |||
| log.warn('GDB Python API is supported only for local processes') | |||
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I don't like changing this without tests that proove full support. Then we could just remove the warning altogether. Which runner did work for you other than a process?
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ssh.process works for me.
This makes sense IMO, because gdb is still run on the host session therefore attaching the gdb api through a unix socket still works. Changing it into a warning for ssh.process and an error for everything else
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7305502: GDB Python API is now a warning for ssh.process and an error for everything else
pwnlib/gdb.py
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| if not port: | ||
| # Find what port we need to connect to | ||
| if ssh or context.native or (context.os == 'android'): | ||
| port = _gdbserver_port(gdbserver, ssh) |
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I think we should still parse the output even though the port is specified explicitly. There were problems with shells forking when gdbserver uses them causing stalls which were detected by a timeout on the message in _gdbserver_port recently. And this way we're sure gdbserver is up and running before trying to attach.
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7305502: now using gdbserver_port to check if the correct port was set
+ gdb.debug port is now also used for qemu + GDB Python API is now tested for tubes.process.process a warning for ssh.process and an error for everything else + updated docs to use mention that gdbserver ports are randomized by default + now using gdbserver_port to check if the correct port was set + fixed CHANGELOG.md structure
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Addressed change requests in 7305502. regarding:
The initial reason this has turned into a "plugin" i maintain myself is so i can basically make changes whenever i encounter a problem or run into an issue (or want to add a new feature). Generally speaking I don't mind adding the functionality to upstream, but this might require some time because
Maybe we can move this discussion somewhere else? My discord tag is @gfelber (I'm also on the official discord server). |
peace-maker
changed the title
port, gdb_args, and gdbserver_args to gdb.debug()
| raise ValueError('GDB Python API is supported only for local processes') | ||
| if runner is not ssh.process: | ||
| raise ValueError('GDB Python API is supported only for local processes') | ||
| log.warn('GDB Python API for ssh processes is not officially tested') |
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It would be better to add the tests instead of this vague warning. I think we can copy the API tests and slap a ssh=shell argument to the .debug call.
See here for instructions on how to test locally. make -C travis/docker ANDROID=no TARGET=gdb.rst should do the job.
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Ah, lol. gdb tests are disabled in the docker testing setup apparently. CI will do the work then.
pwntools/travis/docker/doctest3
Lines 27 to 29 in 51e8eb0
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I just tried running the gdb tests in docker and they all passed, so I guess we can just remove that line from doctest3 and include them.
added two arguments to gdb.debug()
also downgraded "GDB Python API is supported only for local processes" to a warning, because it seems to work.
These changes are made for compatibility with my pwntools "plugin" vagd which currently uses a workaround on Pwngd.debug() (basically the same behaviour as the patch)