Imagine a scenario where you have just system access on android , and you want to continually have it, so you use the su binary, with the correct permission and the setuid flag on, and the owner being system, you do:
chown 1000:1000 su2 chown 06755 su2
06775 being the permission code to all have execution permission, and the setuid flag on.
But when dealing with system permission that doesn't work. it only works with root.
I know it's a weird question, but if any could answer it, id be glad .... thanks