MmAllocateContiguousMemory?   

Q1. In MSDN, it says that MmAllocateContiguousMemory first attemps to 
allocate a continuous range of memory from Nonpaged pool, if it fails, then 
allocates from unused pages. So, here, if it fails allcating from Nonpaged 
pool and then successfully allocates the continuous range of memory, is this 
continuous range of memory still nonpaged or not?

Q2. MmBuildMdlForNonPagedPool, this routine receives an MDL that specifies a 
virtual memory buffer in nonpaged pool, and updates it to describe the 
underlying physical pages. And the MDL virtual address that is input must be 
within the nonpaged portion of system space. So, here, if 
MmAllocateContiguousMemory fails to allocate the continuous memory in 
nonpaged pool but successfully allocates from unused pages, can I still call 
MmBuildMdlForNonPagedPool to build my MDL?

Q3. If a memory is allcated from nonpaged pool, do I still call 
MmProbeAndLockPages and then call MmMapLockedPages to map a system space VA 
to user space VA? or directly call MmMapLockedPages to map?

Q4. 
In MSND, it says
VOID 
  MmProbeAndLockPages(
    IN OUT PMDL  MemoryDescriptorList,
    IN KPROCESSOR_MODE  AccessMode,
    IN LOCK_OPERATION  Operation
    );
Operation 
Specifies the type of operation for which the caller wants the access rights 
probed and the pages locked, one of IoReadAccess, IoWriteAccess, or 
IoModifyAccess.

If I want the access rights to be read, write and modify, how should I do? 
Set the third parameter as IoReadAccess | IoWriteAccess | IoModifyAccess or 
otherwise?

date: Thu, 12 Jun 2008 11:15:00 -0700   author:   Danial.F