Android's default su

Question

Root Checker fails on Android's default su (built from AOSP), but in adb shell it works fine. It seems this su program doesn't provide root access to the Android framework. But I don't quite know the details. Is there anyone who can explain it? Thanks.

Answer 1

I think Chris pointed out the reason in his comment. su works on an engineering build, but not on a factory ROM. It looks like this has something to do with build flags.

Answer 2

Root Checker usually gives you the detailed explanation, why it thinks something is wrong. Please refer to the Root Checker output or copy/paste it to your question if you need further clarification.

Answer 3

How did you install the su program? To actually be useful it needs to have the setuid flag set. If you didn't set it, su won't work properly. Root Checker and similar tools likely check for the flag, so that is why it fails. Runs ls -l /path/to/su to verify flags and permissions.