VirtualQuery

Information about a range of pages within the virtual address space of the calling process can be obtained with the VirtualQuery function:

Parameters

lpAddress

The base address of the region of pages to be queried. This value is rounded down to the next host-page-address boundary.

lpBuffer

Points to a buffer that receives a MEMORY_BASIC_INFORMATION structure containing information about the specified page range. The MEMORY_BASIC_INFORMATION structure has the following format:

typedef struct _MEMORY_BASIC_INFORMATION { /* mbi */

PVOID BaseAddress;

PVOID AllocationBase;

DWORD AllocationProtect;

DWORD RegionSize;

DWORD State;

DWORD Protect;

DWORD Type;

} MEMORY_BASIC_INFORMATION;

typedef MEMORY_BASIC_INFORMATION *PMEMORY_BASIC_INFORMATION;

dwLength

Specifies the length in bytes of the memory information buffer.

Return Value

The return value is the actual length of the information stored in the buffer.

This function provides the capability to determine the state, protection, and type of a region of pages within the virtual address space of the calling process.

The state of the first page within the region is determined and then subsequent entries in the process address map are scanned from the base address upward until either the entire range of pages has been scanned or until a page with a nonmatching set of attributes is encountered. The region attributes, the length of the region of pages with matching attributes, and an appropriate status value are returned.