Kernel-SU / binder_rs

binder_rs

The stub libbinder_ndk.so in ndk's sysroot hides some apis, so that we cannot link our libbiner_rs to it. However, we can rebuild a stub so to make linker happy. The stub source is generated from symbols.txt, whose contents are extracted from prebuilt libbinder_ndk.so from aosp-mainline.

The libbinder_ndk.so is introduced in api-29, you need to compile it with specified target api level. The compilation won't failed if api is lower than 29, because we build the dynamic library on ourselves.

We use ndk-build to build the stub so, ANDROID_NDK_HOME must be set in your env !

sys/src/include_* from platform/frameworks/native/libs/binder/ndk

Example

1. Build

   cargo ndk -t arm64-v8a --platform=29 --bindgen build
   

2. Push file to phone

   adb push target/aarch64-linux-android/debug/binder-example /data/local/tmp
   

3. Run 2 adb shell

   Run server:

   adb shell
   su -c /data/local/tmp/binder-example server
   

   Run client:

   adb shell
   su -c /data/local/tmp/binder-example client
   

Test

1. Build

   cargo ndk -t arm64-v8a --platform=29 --bindgen build
   

2. Push files to phone

   adb push target/aarch64-linux-android/debug/binder-tests /data/local/tmp
   

3. Build unittest binary

   cargo ndk -t arm64-v8a --platform=29 --bindgen test --bin binder-tests --no-run
   

4. Push files to phone

   adb push target/aarch64-linux-android/debug/deps/binder_tests-acf830ec15b8864e /data/local/tmp
   

5. Run test

   adb shell
   cd /data/local/tmp/ && su -c ./binder_tests-acf830ec15b8864e
   

   if you see error like this

   CANNOT LINK EXECUTABLE "/data/local/tmp/binder_tests-acf830ec15b8864e": cannot locate symbol "AIBinder_DeathRecipient_setOnUnlinked" referenced by "/data/local/tmp/binder_tests-acf830ec15b8864e"...
   

   This is because your android version is too low, the source is from android-mainline. You can try in avd, with Android U