Process extensions

[Zoltan Kocsi]

Just a question,

is it possible to attach additional process related information to a 
process descriptor ?

I mean for example a pointer in the PCB which points to any user 
defined data and which does not concern the kernel itself ?

What I'm looking for is a mechanism which I can use to add very low
level features to the kernel (using the pre- and post-context switch
extensions). I need to store extra information about the tasks and I
don't want to do any sort of lookup at switch time. I don't want to
touch the existing source either - I want the new stuff to be an optional
module. I didn't find any formal way of doing that but I may have not
looked hard enough.

Thanks,

Zoltan