import itertools ImportError: dlopen(/Users/k3vin/Library/Android/sdk/ndk/21.0.6113669/prebuilt/darwin-x86_64/lib/python2.7/lib-dynload/itertools.so

[k3vinlusec]

Hi, I was trying to debug .so in an app with gdb, I encountered the following error.
k3vin@Kais-MacBook-Pro bin % ./gdb
Traceback (most recent call last):
File "/Users/k3vin/Library/Android/sdk/ndk/21.0.6113669/prebuilt/darwin-x86_64/share/gdb/python/gdb/init.py", line 143, in auto_load_packages
import(modname)
File "/Users/k3vin/Library/Android/sdk/ndk/21.0.6113669/prebuilt/darwin-x86_64/share/gdb/python/gdb/command/frame_filters.py", line 22, in
from gdb.FrameIterator import FrameIterator
File "/Users/k3vin/Library/Android/sdk/ndk/21.0.6113669/prebuilt/darwin-x86_64/share/gdb/python/gdb/FrameIterator.py", line 17, in
import itertools
ImportError: dlopen(/Users/k3vin/Library/Android/sdk/ndk/21.0.6113669/prebuilt/darwin-x86_64/lib/python2.7/lib-dynload/itertools.so, 2): Symbol not found: _PyBool_Type
Referenced from: /Users/k3vin/Library/Android/sdk/ndk/21.0.6113669/prebuilt/darwin-x86_64/lib/python2.7/lib-dynload/itertools.so
Expected in: flat namespace
in /Users/k3vin/Library/Android/sdk/ndk/21.0.6113669/prebuilt/darwin-x86_64/lib/python2.7/lib-dynload/itertools.so

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(gdb)

GDB is located at /Users/k3vin/Library/Android/sdk/ndk/21.0.6113669/prebuilt/darwin-x86_64/bin

How to fix the error? Thanks!

[k3vinlusec]

The testing system: MacBook Pro, macOS 10.15.2. Could you reproduce it?

[enh-google]

(i see the same on 10.14 if i run ./prebuilt/darwin-x86_64/bin/gdb, so i don't think this is 10.15-specific.)

[k3vinlusec]

I want to use GEF in GDB to debug the app, if this issue won't be fixed, I cannot use GEF in GDB.

[DanAlbert]

@hhb have you had a chance to look at this? Any idea what it will take to fix it?

[k3vinlusec]

I compile the gdb 8.3 source code from google android by myself, and set target aarch64-linux-android, built with python3, it works well with GEF-gdb

[hhb]

I'm still trying to figure out what's happening. _PyBool_Type is defined in libpython2.7.a. libpython is statically linked into gdb binary. But gdb doesn't export any symbol. Linking flag issue?

It is also interesting that this didn't cause any problem on other platforms.

[hhb]

The unstripped binary does have PyBool_Type. Maybe we should not strip it.

[DanAlbert]

IIRC there's a flag to choose specific symbols to avoid stripping. I would assume that if it needs to continue exporting "unused" symbols there's probably a version script that goes with it?

[enh-google]

strip --keep-symbol

[DanAlbert]

Fix is in build 6352462 on https://ci.android.com/builds/branches/aosp-ndk-release-r21/grid?