WdfMemoryAssignBuffer - NtDoc
Native API online documentation, based on the System Informer
(formerly Process Hacker) phnt
headers
// wdfmemory.h
NTSTATUS WdfMemoryAssignBuffer(
[in] WDFMEMORY Memory,
[in] PVOID Buffer,
[in] size_t BufferSize
);
View the official Windows Driver Kit DDI referenceNo description available.
[Applies to KMDF and UMDF]
The WdfMemoryAssignBuffer method assigns a specified buffer to a memory object that a driver created by calling WdfMemoryCreatePreallocated.
Memory [in]A handle to a framework memory object that was obtained by calling WdfMemoryCreatePreallocated.
Buffer [in]A pointer to a driver-supplied buffer.
BufferSize [in]The nonzero size, in bytes, of the buffer that Buffer points to.
WdfMemoryAssignBuffer returns STATUS_SUCCESS if the operation succeeds. Otherwise, this method might return one of the following values:
| Return code | Description |
|---|---|
| STATUS_INVALID_PARAMETER | An invalid parameter was detected. |
This method also might return other NTSTATUS values.
A bug check occurs if the driver supplies an invalid object handle.
The method can assign a buffer to a memory object that WdfMemoryCreatePreallocated created, but not to a memory object that WdfMemoryCreate created.
The buffer that the Buffer parameter points to can be allocated from the pageable or non-pageable memory pool. If the driver allocates the buffer from the pageable pool, or if the buffer is from pageable pool because it came from a user-mode application, the driver must access the buffer only at IRQL < DISPATCH_LEVEL. (Note that the driver's EvtCleanupCallback and EvtDestroyCallback callback functions, if provided, can be called at IRQL <= DISPATCH_LEVEL.)
For more information about framework memory objects, see Using Memory Buffers.
The following code example allocates a buffer and then assigns the buffer to a framework memory object.
PVOID pNewBuffer = NULL;
pNewBuffer = ExAllocatePoolWithTag(
NonPagedPool,
NEW_BUFFER_SIZE,
MY_DRIVER_TAG
);
if (pNewBuffer == NULL){
goto Error;
}
status = WdfMemoryAssignBuffer(
memHandle,
pNewBuffer,
NEW_BUFFER_SIZE
);