Android：调试共享库

Question

I'd like to debug android NDK application, more precisely - I want to check what arguments ( r4 - r8 r1 - r4 registers) are passed to function from shared library in apk.

What I have tried:

• I've run gdbserver :1234 --attach on the device
• I've run arm-linux-androideabi-gdb from ndk package by Google on the PC
• I've set solib-search-path and written target remote :1234

So far, so good. Now I try to set breakpoint ( break <function name> ) (function name from objdump), but I get repond: Cannot access memory at address <...> . info shared says the library is loaded, Does it mean I can't set breakpoint there? Or am I doing something wrong?

Answer 1

One of the things it to copy both the , a file called and the generated .so
into a hidden folder called .
There you will have to add the libraries you would like to debug because the symbols are
referencing them.
The libraries are copied from the device to your PC by some adb shell pull - commands.
http://www.professional-android-development.com/articles/android-ndk-large-c-projects
When placing the libraries into the right folder, you can set your breakpoints.
Still, for some internal reasons, they can fail.
In this case run ndk-gdb --start (the first try will also fail), enforce the application to close and rerun ndk-gdb --start (this time not forcing the application to close).

Answer 2

"Cannot access memory at address <...>" usually means there is a mismatch between the .so file on your PC and the .so file that is on Android. Did you recompile and reinstall?

Btw, what is the reason you're not using "ndk-gdb"? That's a script (part of the NDK) that takes care of all the gory details for you.