#ifndef _NTMMAPI_H
//
// Virtual memory
//
#if (PHNT_MODE != PHNT_MODE_KERNEL)

/**
 * Flushes the instruction cache for a specified process.
 *
 * @param ProcessHandle A handle to the process whose instruction cache is to be flushed.
 * @param BaseAddress A pointer to the base address of the region of memory to be flushed.
 * @param RegionSize A pointer to a variable that specifies the size of the region to be flushed.
 * @param IoStatus A pointer to an IO_STATUS_BLOCK structure that receives the status of the flush operation.
 * @return NTSTATUS Successful or errant status.
 */
NTSYSCALLAPI
NTSTATUS
NTAPI
NtFlushVirtualMemory(
    _In_ HANDLE ProcessHandle,
    _Inout_ PVOID *BaseAddress,
    _Inout_ PSIZE_T RegionSize,
    _Out_ PIO_STATUS_BLOCK IoStatus
    );

#endif
#endif
View code on GitHub

#ifndef _NTZWAPI_H

NTSYSCALLAPI
NTSTATUS
NTAPI
ZwFlushVirtualMemory(
    _In_ HANDLE ProcessHandle,
    _Inout_ PVOID *BaseAddress,
    _Inout_ PSIZE_T RegionSize,
    _Out_ PIO_STATUS_BLOCK IoStatus
    );

#endif
View code on GitHub