KMDF驱动中如何通过内存映射读写硬盘原始数据
时间: 2024-02-27 07:56:08 浏览: 22
在 KMDF 驱动中,可以通过内存映射的方式来读写硬盘的原始数据。具体来说,可以使用 `MmMapLockedPagesSpecifyCache` 函数将物理内存页面映射到驱动程序的虚拟地址空间中,然后使用指针访问这些内存页面,实现对硬盘数据的读写。
以下是一个示例代码:
```C
NTSTATUS ReadWriteRawDiskData(PDEVICE_OBJECT DeviceObject, ULONGLONG Offset, PVOID Buffer, ULONG Length, BOOLEAN IsWrite)
{
NTSTATUS Status;
PPHYSICAL_MEMORY_RANGE PhysicalRanges = NULL;
ULONG PhysicalRangeCount = 0;
PHYSICAL_ADDRESS PhysicalAddress;
PVOID MappedAddress = NULL;
ULONG_PTR MdlHack;
ULONG_PTR PageOffset;
ULONG_PTR PageCount;
ULONG_PTR i;
// Calculate the physical memory ranges that correspond to the buffer
Status = IoGetDmaAdapter(DeviceObject, NULL, &PhysicalRanges, &PhysicalRangeCount);
if (!NT_SUCCESS(Status))
{
return Status;
}
PhysicalAddress.QuadPart = Offset;
MappedAddress = MmMapLockedPagesSpecifyCache(PhysicalRanges, PhysicalRangeCount, MmCached, NULL, FALSE, HighPagePriority | MdlMappingNoExecute);
if (MappedAddress == NULL)
{
IoFreeMapRegisters(DeviceObject->DeviceExtension, PhysicalRanges, PhysicalRangeCount);
return STATUS_INSUFFICIENT_RESOURCES;
}
// Calculate the page offset and the number of pages
MdlHack = (ULONG_PTR)(MappedAddress);
PageOffset = MdlHack & (PAGE_SIZE - 1);
PageCount = ADDRESS_AND_SIZE_TO_SPAN_PAGES(MdlHack - PageOffset, Length + PageOffset);
// Adjust the physical address to point to the correct page
PhysicalAddress.QuadPart -= PageOffset;
if (IsWrite)
{
// Write the data to the mapped memory
RtlCopyMemory((PVOID)((ULONG_PTR)MappedAddress + PageOffset), Buffer, Length);
}
else
{
// Read the data from the mapped memory
RtlCopyMemory(Buffer, (PVOID)((ULONG_PTR)MappedAddress + PageOffset), Length);
}
// Flush the data to the disk
KeFlushIoBuffers(MappedAddress, Length);
// Unmap the memory
MmUnmapLockedPages(MappedAddress, NULL);
IoFreeMapRegisters(DeviceObject->DeviceExtension, PhysicalRanges, PhysicalRangeCount);
return STATUS_SUCCESS;
}
```
在调用 `ReadWriteRawDiskData` 函数时,需要指定要读写的设备对象、读写的偏移量、读写的数据缓冲区以及要读写的数据长度等参数。例如:
```C
ReadWriteRawDiskData(DeviceObject, 0x1000, pData, 0x100, FALSE);
```
这将从设备对象 `DeviceObject` 的偏移量 `0x1000` 处开始读取长度为 `0x100` 字节的数据到缓冲区 `pData` 中。
需要注意的是,通过内存映射读写硬盘数据需要谨慎操作,因为这可能会对硬盘的数据造成破坏。在进行读写操作之前,需要确保已经对硬盘进行了备份,并且已经获得了足够的权限来进行操作。