I’m currently working on debugging some code with my android project.
I’m having an issue getting gdb to hit my breakpoints on secondary threads. Everything works fine when they’re set on the main thread, but as soon as a breakpoint is hit on a secondary one, my app crashes.
I’ve searched the web and some people were saying that the ndk uses an old version of GDB, but this appears to be irrelevant now (as the version shipped with the ndk r8 gives 7.3.1). One other site had said that the gdb version that’s included was compiled without multithreading support, but I can’t seem to verify this either.
Additional Details:
- Device : Nexus S
- OS: Android 4.1.1
I’m not sure if this is related or not, but I get the following output when I attach my debugger to the running application (seems to only have issues with symbols):
warning: .dynamic section for "/home/sandy/workspace/tumbleweed/obj/local/armeabi-v7a/linker" is not at the expected address (wrong library or version mismatch?)
warning: Could not load shared library symbols for 78 libraries, e.g. libstdc++.so.
Use the "info sharedlibrary" command to see the complete listing.
Do you need "set solib-search-path" or "set sysroot"?
warning: Unable to find dynamic linker breakpoint function.
GDB will be unable to debug shared library initializers and track explicitly loaded dynamic code.
Also, here’s my verbose output when running ndk-gdb –verbose:
Android NDK installation path: /home/sandy/workspace/android-ndk-r8b
Using default adb command: /home/sandy/workspace/android-sdk/platform-tools/adb
ADB version found: Android Debug Bridge version 1.0.29
Using ADB flags:
Using auto-detected project path: .
Found package name: com.sandroid.tumbleweed
ABIs targetted by application: jni/../libs
/home/sandy/workspace/tumbleweed/libs/gtest-1.6.0
/home/sandy/workspace/tumbleweed/libs/gtest-1.6.0/lib/.libs/libgtest.a
armeabi-v7a
Device API Level: 16
Device CPU ABIs: armeabi-v7a armeabi
Compatible device ABI: armeabi-v7a
Using gdb setup init: ./libs/armeabi-v7a/gdb.setup
Using toolchain prefix: /home/sandy/workspace/android-ndk-r8b/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/arm-linux-androideabi-
Using app out directory: ./obj/local/armeabi-v7a
Found debuggable flag: true
Found device gdbserver: /data/data/com.sandroid.tumbleweed/lib/gdbserver
Found data directory: '/data/data/com.sandroid.tumbleweed'
Found running PID: 3539
Launched gdbserver succesfully.
Setup network redirection
## COMMAND: adb_cmd shell run-as com.sandroid.tumbleweed lib/gdbserver +debug-socket --attach 3539
## COMMAND: adb_cmd forward tcp:5039 localfilesystem:/data/data/com.sandroid.tumbleweed/debug-socket
## COMMAND: adb_cmd pull /system/bin/app_process ./obj/local/armeabi-v7a/app_process
Attached; pid = 3539
Listening on sockaddr socket debug-socket
118 KB/s (9572 bytes in 0.078s)
Pulled app_process from device/emulator.
## COMMAND: adb_cmd pull /system/bin/linker ./obj/local/armeabi-v7a/linker
844 KB/s (79976 bytes in 0.092s)
Pulled linker from device/emulator.
## COMMAND: adb_cmd pull /system/lib/libc.so ./obj/local/armeabi-v7a/libc.so
1662 KB/s (286500 bytes in 0.168s)
Pulled libc.so from device/emulator.
When the app crashes, I get this:
Child terminated with signal = 5
Child terminated with signal = 0x5 (SIGTRAP)
GDBserver exiting
It’s been a while since I’ve posted this, but I think I recall figuring it out. Turns out I had recently updated NDK versions and didn’t quite migrate all of the references to the old NDK directory. After completely moving the old NDK directory into a backup directory, I fixed the lingering references in my Eclipse project. After rebuilding, this seemed to fix my problems.
TL;DR: Ensure your NDK references are correct.