Question

We just got a midterm project today for my “operating systems” course, we are requested to implement a system call (and I guess I assume we’ll have to write a piece of code to call it).

I understand I’ll need to update the table of the system calls (can’t remember the name, but no biggie), as well as create a kernel module that the table will point to, but does this mean I’ll have to recompile the whole kernel, so the kernel knows about my module?

I have seen that it’s possible to hijack a current system call, but I suspect that I won’t get credit for my assignment if I do it that way.

Just wanted to get a feel for the size of the effort I’ll be making.

UPDATE:
Well it kinda ended up being a hassle, they change some things from I believe 2.6.32 forward, so when I went back to a previous kernel version specific to the tutorials online I found, it was really easy to follow. If anyone catches this online and are following a tutorial, initially I would recommend downloading the same kernel in the tutorial initially, then move forward from there once you have an understanding of what you’re doing. If you’re really familiar with compiling kernels, etc, you might not have an issue, but this was my first time compiling a kernel, so it was a pain to compile for 2 hours and then find out something didn’t work, and have to do it all over again, especially when I wasn’t sure what I was/wasn’t doing wrong.

Answer 1

but does this mean I’ll have to recompile the whole kernel, so the kernel knows about my module?

Yes, you will need to recompile the kernel.

• Implementing Linux System Calls