typedef struct _SEGMENT_OBJECT
{
     PVOID BaseAddress;
     ULONG TotalNumberOfPtes;
     LARGE_INTEGER SizeOfSegment;
     ULONG NonExtendedPtes;
     ULONG ImageCommitment;
     PCONTROL_AREA ControlArea;
     PSUBSECTION Subsection;
     PMMSECTION_FLAGS MmSectionFlags;
     PMMSUBSECTION_FLAGS MmSubSectionFlags;
} SEGMENT_OBJECT, *PSEGMENT_OBJECT;

Windows Vista Kernel Structures