I have the SuperSU installed (with su binary in /system/xbin), and another su binary compiled from SuperUser sources by myself.
I want to replace the existing su binary by my one via the command line.
But when I'm trying to do this, I'm getting an error:
# cp /sdcard/su /system/xbin/ cp: /system/xbin/su: Text file busy
Of course, the existing one is busy because it's in use now. Is there any way to replace it with command line only? I can't do it from recovery.