On Tue, Feb 19, 2013 at 10:18 PM, horseriver <horserivers@gmail.com> wrote:

On Mon, Feb 18, 2013 at 12:25:43PM +0000, Anuz Pratap Singh Tomar wrote:

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On Mon, Feb 18, 2013 at 1:55 AM, horseriver <horserivers@gmail.com> wrote:

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Intel® 64 and IA-32 Architectures Software Developer’s Manual Volume 3A: System Programming Guide, Part 1 page 65

The linear address of the base of the GDT is contained in the GDT register (GDTR); the linear address of the LDT is contained in the LDT register (LDTR).

Thanks!

As the value is a linear address , so when load an segment descriptor from an address , such as lss ubstruction: lss 0x10023,%esp , cpu will check to make sure this stack descriptor exist in gdt . So , we will get a linear address by the gdtr value and the descriptor's index , then *if this linear address* has not phisical page mapped , it will cause a pagefault trap.then ,how to resolve this trap?

Please use reply all or add kernelnewbies to CC I am not very sure of how this trap will be resolved, but you can have a look at this: Understanding Linux Kernel Section 9.4

http://www.makelinux.net/books/ulk3/understandlk-CHP-9-SECT-4

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However for 32 bit registers, this document provides some details in protected mode:

http://home.swipnet.se/smaffy/asm/info/PMODEDetailedApproach.txt

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thanks!

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-- Thank you Warm Regards Anuz

-- Thank you Warm Regards Anuz