IoAllocateDriverObjectExtension - NtDoc
Native API online documentation, based on the System Informer
(formerly Process Hacker) phnt
headers
// wdm.h
NTSTATUS IoAllocateDriverObjectExtension(
[in] PDRIVER_OBJECT DriverObject,
[in] PVOID ClientIdentificationAddress,
[in] ULONG DriverObjectExtensionSize,
[out] PVOID *DriverObjectExtension
);
View the official Windows Driver Kit DDI referenceNo description available.
The IoAllocateDriverObjectExtension routine allocates a per-driver context area, called a driver object extension, and assigns a unique identifier to it.
DriverObject [in]Pointer to a driver object to which the context area will be associated.
ClientIdentificationAddress [in]Specifies a unique identifier for the context area to be allocated.
DriverObjectExtensionSize [in]Specifies the length, in bytes, of the context area to be allocated.
DriverObjectExtension [out]Pointer to, on completion, the allocated context area.
IoAllocateDriverObjectExtension returns one of the following NTSTATUS codes:
| Return code | Description |
|---|---|
| STATUS_SUCCESS | Indicates that the routine allocated an extension of the requested size. |
| STATUS_INSUFFICIENT_RESOURCES | Indicates that the memory could not be allocated for the driver object extension. |
| STATUS_OBJECT_NAME_COLLISION | Indicates that a driver object extension with the given ClientIdentificationAddress already exists. |
Memory allocated by the system for the driver object extension is resident storage and is accessible from any IRQL. The allocated storage is automatically freed by the I/O manager when the driver object is deleted.
Callers of this routine must provide a unique identifier for ClientIdentificationAddress. To retrieve a pointer to the context area, a caller passes the ClientIdentificationAddress to IoGetDriverObjectExtension.