Why I can achieve in the cmd but can not be achieved in my android application code

[lq19931201]

Why I can achieve in the console but can not be achieved in the code
/system/bin/run-as

[droidvoider]

The run-as code is just a template proof of concept which does in fact work on some devices albeit very limited. It is your task to customize the approach for your specific device. This may not include run-as at all, and in fact for Note 5 I have not had any success with run-as. dirtycow is the the business end of that tool and what you use to craft your own method.

Anything that is going to work will need to be written and compiled using AOSP for your specific device android branch. If your target device is spanning multiple firmware versions this will be separate compilations using aosp source. I do not recommend this patch tool on a system that doesn't rebuild itself on boot, that would be such a painful way to learn.