what is privilege ring of CPU (0 and 3) can you give a detil about that ??
may i know where is the place to find some guide or reference
about user space and kernel space
On Thu, Sep 16, 2010 at 6:32 PM, arshad hussain <arshad.super@xxxxxxxxx> wrote:
On 9/16/2010 11:56 AM, jhoni maux wrote:Here I think 'user space context' and 'user space' implies
HI,
Now i'm learn kernel module programming, but i'm still confuse about
user space context and kernel space context.
the same thing.So...
anyone know about what
the different between user space and kernel space and how to see the
underlaying between user space and kernel space ??
In 'Kernel space' the running program can access all the
CPU instruction set. While in user space the programs
has access to limited CPU instruction. This is accomplished
through setting proper privilege bits in the Segment selector
and Descriptors. For example 'user space' program cannot issue
cli instruction...
CPU designers also call 'kernel space' as Ring0. while
'user space' is known as Ring3.
Thanks
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