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05.06.2008 at 11:05PM PDT, ID: 23381761
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7.5

How Linux kernel differentiate between virtual address space for kernel and virtual address space for user process

Asked by hirakpatel in Linux Programming, Processor Programming for Specific Platforms, Kernel And Operating System Specific Programming

Tags: , , ,

I am trying to understand how Linux kernel differentiates between virtual address space of kernel and virtual address space of user space process for Intel CPU architecture .
Linux KERNEL loads at PAGE_OFFSET 0xc0000000 which is start of virtual address space for kernel, while User space process uses virtual address less then 0xc0000000 (0-3GB).
Physical memory RAM address mapped to 0x0 to kernel virtual address space 0xc0000000 (LOW_MEM 0-896 MB)
So my questions:

1.      Where are page tables for kernel virtual address space and page table for user process virtual  
address space? When page tables for kernel and process virtual address space get  loaded in CPU?

2.      How both virtual address spaces are  handled in Linux   ?

3.      What happen at the time of system call from user space process to kernel in terms of this both virtual address space?
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[+][-]05.07.2008 at 01:05PM PDT, ID: 21519901

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About this solution

Zones: Linux Programming, Processor Programming for Specific Platforms, Kernel And Operating System Specific Programming
Tags: linux, linux kernel, 2.6.18, Linux memory management
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Solution Provided By: ravenpl
Participating Experts: 1
Solution Grade: B
 
 
[+][-]05.11.2008 at 07:13AM PDT, ID: 21542491

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[+][-]05.11.2008 at 09:25AM PDT, ID: 21542810

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