LONG
FIELD_OFFSET(
IN TYPE Type,
IN PCHAR Field
);
FIELD_OFFSET returns the byte offset of a named field in a known structure type.
Returns the byte offset of the caller supplied Field in the Type structure.
Used by device driver writers to symbolically determine the offset of a known field in a known structure type.
Callers of FIELD_OFFSET can be running at any IRQL as long as the structure is resident. If a page fault could occur, callers must be at or below IRQL APC_LEVEL.