Debugging Android native shared libraries | Hacker News Reader

Debugging Android native shared libraries

blog.dornea.nu

22 pointssyngres3 comments

I would like to note that IDA Pro has a very nice debug server which is a nice alternative to GDB for Android. Also I believe they recently added the ability to debug dalvik bytecode as well.

Gikdbg is a free alternative, which I believe is a UI wrapper around GDB. What's interesting about it is that it works for iOS and Android: http://gikir.com/product.php

It's a beta product, so it might take some work to get going, but once you do it makes you much more productive... especially if you feel at home with Ollydbg :)

Last time my coworker tried to use an older IDA's debug server on Android, it wouldn't work. The device was API >= 14 so it required PIE executables and the IDA debug server was not. Unfortunate. Luckily IDA 6.8 has a PIE and non-PIE versions. I also believe that the debug server source is now included in the SDK, so you could have supposedly rebuilt it in PIE mode yourself.

As someone that works on a native-only app (using Qt's bindings), it has bugged me significantly that Android apk's absolutely cannot handle versioned libraries nor files without the .so prefix.

For instance, bundling the "gdbserver" file that comes with Google's NDK into the armeabi folder to have gradled up and deploy in a debug version of an apk will not pack up "gdbserver". And if you have libtinyxml2.so with the SOVERSION as 3.0? Good luck getting that bundled up into your apk! Recompile without versioning! Or manually adb push it every time you reinstall your application. [0]

OK sure you can bundle that up into your apk by skipping gradle and manually adding and zipaligning it. But then adb will not unpack it onto the phone. So you are stuck back at square one.

I won't even get into the modifications I've made to my NDK python script with launching gdb. Suffice to say using gdb to debug nontrivial native android applications is full of rough edges.

[0] https://code.google.com/p/android/issues/detail?id=98308

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