Re: win32/memory locking (Re: Reply to EFS note on Bugtraq)

[James Perry <jeperry () UWATERLOO CA>]

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> Bits _never_ get written to the disk? Guaranteed never to use swap space?
>
> The GnuPG FAQ (http://www.gnupg.org/faq.html#q6.1) suggests that it is
> not possible to make a Windows program insist on physical RAM the way a
> program can in Open Systems. Does EFS really use only physical RAM? If
> so, is there some win32 API that can be used by other application designers
> who want to guarantee that certain blocks of allocated memory are *never*
> swapped out to disk? The most likely candidate I've come across is
> VirtualLock() which, unfortunately, "does not mean that the page will not be
> paged to disk" (http://msdn.microsoft.com/library/techart/msdn_virtmm.htm).
>
> Thanks,
>
> -Peter

As described on the MSDN site:
"The AllocateUserPhysicalPages function is used to allocate physical
memory. Memory allocated by this function must be physically present in
the system. Once allocated, it is locked down and unavailable to the rest
of the virtual memory management system of Windows 2000."

_http://msdn.microsoft.com/library/psdk/winbase/memman_0u5v.htm_

The UserPhysicalPages class of functions appear to be directly related to
kernel calls, so I'd take a guess and say it's probably what you're
looking for.

 - James Perry
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