How to debug a dynamic library on Android

For details about how to debug the gdb process on Android, refer to the previous article.

If an android application contains a dynamic library call, a bunch of addresses are provided after the application exits unexpectedly,

For example

I/debug (841): Signal 11 (SIGSEGV), fault ADDR deadbaad
I/debug (841): R0 00000000 R1 afd1498d R2 00000027 R3 00000070
I/debug (841): R4 afd42328 R5 00000000 R6 00000000 R7 4e6fae30
I/debug (841): R8 00100000 R9 a811c2f9 10 4e5fb000 FP 0013cdb8
I/debug (841): IP Route 173c SP 4e6fa9d8 LR deadbaadPC afd11f40Cpsr60000030
I/debug (841): D0 400000003 eaaaaab D1 3ff0000041f00000
I/debug (841): D2 rj000050baf6de D3 0000000000000000
I/debug (841): D4 00000007000000b4 D5 3fe999999999999a
I/debug (841): D6 3fe1_0000binder: Release proc 1047, transaction 109259, not freed
0 D7 3eaaaaab3f800000
I/debug (841): D8 0000000000000000 D9 0000000000000000
I/debug (841): D10 0000000000000000 D11 0000000000000000
I/debug (841): D12 0000000000000000 D13 0000000000000000
I/debug (841): D14 0000000000000000 D15 0000000000000000
I/debug (841): SCR 80000012

The problematic code location can be inferred based on the PC address and the crash dynamic library,

Location from address to code location using the GCC command arm-eabi-addr2line:

For example, if my dynamic library is Hello. So, place the library locally.
Run

Arm-eabi-addr2line
-C-f-e/path/to/lib/with_sysbols/Hello. So
Afd11f40

The aboveAfd11f40
The PC address when it is crash:

(I/debug
(841): IP Route 173c SP 4e6fa9d8 LR deadbaadPC afd11f40Cpsr60000030

Note:

1. It is best to compile your dynamic debugging version (-g)

2. Put your dynamic experience in the android dynamic library
Sysbols version directory. For example, the directory on my machine is: (eg.)/home/usera/Android/out/target/product/generic/symbols/system/lib.