fxrequestbufferum.cpp

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/*++
 
Copyright (c) Microsoft. All rights reserved.
 
Module Name:
 
    FxRequestBufferUm.cpp
 
Abstract:
 
    This module implements a memory union object
 
Author:
 
 
 
Environment:
 
    User mode only
 
Revision History:
 
--*/
 
#include "FxSupportPch.hpp"
 
extern "C" {
#include "FxRequestBufferUm.tmh"
}
 
_Must_inspect_result_
NTSTATUS
FxRequestBuffer::GetOrAllocateMdl(
    __in PFX_DRIVER_GLOBALS FxDriverGlobals,
    __deref_out_opt PMDL*   Mdl,
    __inout PMDL*           MdlToFree,
    __inout PBOOLEAN        UnlockWhenFreed,
    __in LOCK_OPERATION     Operation,
    __in BOOLEAN            ReuseMdl,
    __inout_opt size_t*     SizeOfMdl
    )
/*++
 
Routine Description:
 
    This function attempts to reuse the passed-in MDL (if any) or allocates
    a new MDL if reuse flag isn't passed-in or if the existing MDL isn't
    big enough.
 
Arguments:
 
Return Value:
    FxDriverGlobals - Driver globals
 
    Mdl - on return it contains the MDL allocated/reused
 
    MdlToFree - pointer to any MDL
                  * to be reused, if the size is <= current size, or
                  * freed and set to newly allocated MDL
 
    UnlockWhenFreed - whether to unlock pages when freeing MDL
                      (if FALSE, MDL may represent just MDL buffer but the pages
                      might have already been unlocked)
 
    Operation - Operation to pass to MmLockPages
 
    ReuseMdl - whether to reuse *MdlToFree
               Please note that this can be FALSE even when MDL is supplied
 
    SizeOfMdl - on input contains size of *MdlToFree,
                on return contains size of *Mdl
 
Remarks:
 
    *MdlToFree is modified only when this function frees the passed in MDL
    Otherwise it leaves it untouched. Caller is responsible for storing
    properly initialized value and/or freeing what's stored in the value.
 
  --*/
{
    UNREFERENCED_PARAMETER(FxDriverGlobals);
    UNREFERENCED_PARAMETER(Mdl);
    UNREFERENCED_PARAMETER(MdlToFree);
    UNREFERENCED_PARAMETER(UnlockWhenFreed);
    UNREFERENCED_PARAMETER(Operation);
    UNREFERENCED_PARAMETER(ReuseMdl);
    UNREFERENCED_PARAMETER(SizeOfMdl);
 
    UfxVerifierTrapNotImpl();
    return STATUS_NOT_IMPLEMENTED;
}
 
VOID
FxRequestBuffer::SetMemory(
    __in IFxMemory* Memory,
    __in PWDFMEMORY_OFFSET Offsets
    )
{
    DataType = FxRequestBufferMemory;
    u.Memory.Memory = Memory;
    u.Memory.Offsets = Offsets;
}