yeah it does seems like a homework question..
I remember doing it on KernelVersion: 2.6 by modifying some files including unistd.h writing a wrapper for it and writing the code for it. This included some tweaking inside the /arch subtree of the kernel.
my intentions are entirely academic.
Currently working on kernelVer: 3.12.14
I am somewhat struggling to comprehend the changes (steep learning curve), if you could guide me on what files to look for, i am sure i can find my way from there.
and Thanks Greg.
--big fan :)