link question

[Greg Freemyer]

On Wed, Jun 29, 2011 at 1:36 PM, Littlefield, Tyler <tyler at tysdomain.com> wrote:
> I have a quick question; this is something I haven't been able to figure
> out. By using the kernel headers you can call functions that are defined
> in the kernel, but you don't actually have to link to the kernel or any
> sort of library. How does this work? How does compiled code call the
> function if it doesn't link to it in some way or another?.

Is this a question about userspace apps or kernel modules?

Userspace apps link to glibc which in turn has assembly instructions
embedded to call into the kernel.

Kernel Modules get a different kind of magic, but I'm not sure of those details.

Greg