Can't execute task_for_pid after added procmod？

[CodeLife2012]

I run the follow command,

sudo chgrp procmod /path_to_readmem
sudo chmod g+s /usr/path_to_readmem

But still can't execute task for pid.

[CodeLife2012]

Should I need disable rootless?

Seems not work after I disable rootless.

Now it will report

[ERROR] vm_read failed! 1 (readmem, 178)

[gdbinit]

$ man taskgated