I need help to solve the followinig problem:

"Modify the Linux kernel to keep track of the number of read/write system calls and their arguments since boot. Keep track of the number of calls and the average, min and max value of the size argument. Provide an interface to export the collected data to user space."

Where do I have to start to solve it? Where can I count the system calls since boot?
It's very hard for me because I'm new to linux kernel programming, so I'm very happy for any hint.