OSDev.org

Just found the @#$@#$. it took me a while.

Well, it all started with me placing an assert when populating a page table entry. the assert checks that there isn't a previous address in it.
Just when I started implementing clone(), the assert was triggered. and I couldn't understand where the previous address came from.

Turns out that in my copy_page_table function I did some temporary mapping to allow me to write to destination PDT. It was copied also...

damn.

I had to tell someone and my wife doesn't understand

I tried to write to video memory once. And i somehow wrote to ROM (Read Only Memory), according to a memory map.