Most architectures allow a process to
execute in at least two modes:
kernel and user.
In the kernel mode a process can set up translation tables,
change the processor state that determines the mode of the processor,
use the kernel translation table
and execute other privileged instructions,
while in the user mode it uses the process' translation table and
instructions.
Thus these architectures
allow
a process to
switch between the access rights of the user and the kernel.