Getting physical address from /proc/[pid]/pagemap

Question

I am told that I can find the physical address corresponding to a virtual address using /proc/[pid]/pagemap.

I read that this pagemap file is an array of 64-bit entries, with bits 0-54 corresponding to the page frame number. I don't know how to make the leap from this to translating virtual to physical. Partially, I don't know how to find the entry I want in this file; nobody seems to specify how they are indexed.

Also, I don't know if the PFN is virtual or physical. And I don't know what to do with the PFN, regardless. How can I proceed?

Thanks

http://stackoverflow.com/questions/6284810/proc-pid-pagemaps-and-proc-pid-maps-linux — duck, Feb 18 '14 at 03:35
Possible duplicate of [How to decode /proc/pid/pagemap entries in Linux?](https://stackoverflow.com/questions/17021214/how-to-decode-proc-pid-pagemap-entries-in-linux) — Ciro Santilli OurBigBook.com, Aug 04 '17 at 06:04

score 0 · Answer 1 · answered Mar 07 '14 at 21:24

0

Divide the VA by the page size (4096 normally), use that as an offset into /proc/self/pagemap. Then take that number (the page), multiply by the pagesize (4096), and offset that by your VA%4094.

Larry

answered Mar 07 '14 at 21:24

Larry_C

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Getting physical address from /proc/[pid]/pagemap

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