NASM - The Netwide Assembler

NASM Forum => Other Discussion => Topic started by: junior_study on July 20, 2012, 02:16:36 PM

Title: request privilege level check
Post by: junior_study on July 20, 2012, 02:16:36 PM
hi,
  when I  access a memory page,  what  is  the  procedure  of  RPL check?
  cpu will  compare what with the segment's  RPL ?

thank you!
Title: Re: request privilege level check
Post by: yangbowen1 on August 21, 2012, 08:43:17 AM
RPL is specified in the selector INSTEAD OF THE SEGMENT DESCRIPTOR.CPU will check if RPL>=CPL and RPL<=DPL (For data segments). Note that CPL is "current privilege level" and DPL is "descriptor privilege level".
See also: http://www.intel.com/content/www/us/en/processors/architectures-software-developer-manuals.html
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