Chapter 4/ System Briefing

OxFFFFFFFF

Kernel Space

OxSOOOOOOO

Ox7FFFFFFF

FVocess A

User Spacc

Process B

User Spacc

Figure 4.3

F�roeess C

User Space

0x00000000

Another thing to keep in mind is that even though each process has its own

private user spacc, they all share the same kernel space (see Figure 4.3). This

is a necessity, seeing as how there can be only one operating system. This is

implemented by mapping each program's supervisor-level PDEs to the same

set of system page tables (see Figure 4.4).

Figure 44