Page Mapping

["Kuas (gmane)" <ku4s@users.sourceforge.net>]

Hello,

This might be very trivial question for people in this mailing list. I 
need to know if my understanding is correct.

We are doing some experiment with Linux kernel for security. Right now, 
we are trying to see some behavior in the Linux memory management. I am 
trying to track and possibly scan (for now) all the pages that's just 
brought into the memory. I am doing this in i386 arch and Linux kernel 
2.4.22.

I think it would be good to do it in: mm/memory.c in do_no_page(). At 
the end of the function, I have references to pte_t and page struct of 
the fresh new page that's just brought in from disk (not swapped).

This is diagram the diagram I'm going to refer:
http://www.skynet.ie/~mel/projects/vm/guide/html/understand/node24.html

 From my understanding from the diagram of Linear Address to Page 
conversion (please let me know if I'm correct or misunderstood). The 
struct "pte_t->pte_low" an entry if PTE table, is the base 'physical' 
address of the page. In this case I can just use it to reference the 
page. I can't find any other conversion method to get another address.

Assuming I have that address, can I just direct reference that address 
(assuming the address is physical and from kernel mode) or do I have to 
use some methods to access the page content?

How do I know the size of the page that's filled though? I can't see 
that information from the page struct.

Thanks in Advance for comments and information.


Kuas

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