Question

I am tweaking code residing in the /net directory of linux kernel.

I was trying things like printing but I see that there are no relevant headers (like stdlib.h, stdio.h etc). So how can I do this at the kernel level?

Answer 1

You cannot use any user space library functions in kernel, You should use only functions exported by the kernel. So, there will not be stdio.h, stdlib.h, etc. If you want to print something in the kernel, you have the printk() function, this is equivalent to printf() in user space.

See also my blog posts Linux Module Programming Part1 and Part2.