Undocumented functions of NTDLL

2OOO, 3 December

NTSYSAPI 
NTSTATUS
NTAPI
NtFreeVirtualMemory(

  IN HANDLE               ProcessHandle,
  IN PVOID                *BaseAddress,
  IN OUT PULONG           RegionSize,
  IN ULONG                FreeType );

RegionSize
If you put pointer to NULL value as RegionSize, system will free all region, and put size of it in result.

FreeType
Can be one of the values:  MEM_DECOMMIT, or MEM_RELEASE.