Make lookup_page() just return null for uaddr >= PHYS_BASE.
[pintos-anon] / src / userprog / gdt.c
2004-09-06 Ben PfaffRename printk() to printf().
2004-09-05 Ben PfaffRedo makefiles.
2004-09-05 Ben PfaffAdd comments.
2004-09-02 Ben PfaffMove user exception support into userprog.