Device IO的问题，大侠乱入

一个APP（比如一个路由程序），一个SYS（比如一个网络驱动）。
APP更新一次它维护的一段内存以后，通知SYS，SYS将这段内存拷贝到自己分配的一段内存中使用。如此反复。请问通过DEVICE_IO能完成这个操作么？如何实现？目前正在做，遇到不少困难，多谢各位帮助！

完全可以，应用层调用deveiceiocontrol，sys处理IRP，

你先找个例子看看就明白了。

luo，又是你帮我，感动中。真是多谢多谢！
我已经潜水好几天看帖子，也自己写了一个小程序（大部分是拷贝的）
在APP中使用如下代码：
HANDLE hDevice;
DWORD dwDev;
TCHAR szOutputBuffer[20];
PVOID psharememory;

hDevice = CreateFile(\"\\\\\\\\.\\\\My_Passthru\",
GENERIC_READ| GENERIC_WRITE,
0,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL
);

if(hDevice == ((HANDLE)-1))
MyGetLastError();

if(!DeviceIoControl(hDevice,
IOCTL_SHAREMEMORY_GETVADDR,
NULL,
NULL,
szOutputBuffer,
sizeof(szOutputBuffer),
&dwDev,
NULL
))
{
MyGetLastError();
return;
}
psharememory = *((PVOID *)szOutputBuffer);

MessageBox((char *)psharememory, \"ShareMemory\", MB_OK);
strcpy((char *)psharememory, \"Hi, ShareMemory!\");

if(!DeviceIoControl(hDevice,
IOCTL_SHAREMEMORY_SHOWCONTENT,
NULL,
NULL,
NULL,
NULL,
&dwDev,
NULL
))
MyGetLastError();

MessageBox((char *)psharememory, \"ShareMemory\", MB_OK);
CloseHandle(hDevice);
return;
、、、、、、、、、、、、、、、、、

在sys中我采用如下代码：
具体是在PassThru.c中：
DbgPrint(\"begin sharing memory work...\");
RtlInitUnicodeString(&nameString, L\"\\\\Device\\\\My_Passthru\" );

status = IoCreateDevice(DriverObject,
0,
&nameString,
FILE_DEVICE_UNKNOWN,
0,
FALSE,
&deviceObject
);


if (!NT_SUCCESS(status))
return status;

deviceObject->Flags |= DO_BUFFERED_IO;

RtlInitUnicodeString(&linkString, L\"\\\\??\\\\My_Passthru\");

status = IoCreateSymbolicLink (&linkString, &nameString);

if (!NT_SUCCESS(status))
{
IoDeleteDevice (DriverObject->DeviceObject);
return status;
}

DriverObject->MajorFunction[IRP_MJ_CREATE] = MydrvDispatch;
DriverObject->MajorFunction[IRP_MJ_CLOSE] = MydrvDispatch;
DriverObject->MajorFunction[IRP_MJ_DEVICE_CONTROL] = MydrvDispatchIoctl;

SystemVirtualAddress = ExAllocatePool(NonPagedPool, 1024);
Mdl = IoAllocateMdl(SystemVirtualAddress, 1024, FALSE, FALSE, NULL);
MmBuildMdlForNonPagedPool(Mdl);

strcpy(SystemVirtualAddress, \"In Driver\");
DbgPrint((char *)SystemVirtualAddress );
DbgPrint(\"\\n\");

return STATUS_SUCCESS;

}
static NTSTATUS MydrvDispatch(IN PDEVICE_OBJECT DeviceObject, IN PIRP Irp)
{
NTSTATUS status;
PIO_STACK_LOCATION irpSp;

// UNREFERENCED_PARAMETER(DeviceObject);

//µÃµ½µ±Ç°IRP (I/OÇëÇó°ü)
irpSp = IoGetCurrentIrpStackLocation(Irp);

switch (irpSp->MajorFunction)
{
case IRP_MJ_CREATE:
Irp->IoStatus.Status = STATUS_SUCCESS;
Irp->IoStatus.Information = 0L;
break;

case IRP_MJ_CLOSE:
Irp->IoStatus.Status = STATUS_SUCCESS;
Irp->IoStatus.Information = 0L;
break;

case IRP_MJ_CLEANUP:
MmUnmapLockedPages(UserVirtualAddress, Mdl);
break;

default:
break;
}

IoCompleteRequest(Irp, IO_NO_INCREMENT);
return STATUS_SUCCESS;

static NTSTATUS MydrvDispatchIoctl(IN PDEVICE_OBJECT DeviceObject, IN PIRP Irp)
{
PIO_STACK_LOCATION IrpStack;
NTSTATUS status;
ULONG ControlCode;
ULONG InputLength, OutputLength;
TCHAR wInputBuffer[200];
TCHAR OutMsg[] = \"Hello, Application!\";

//µÃµ½µ±Ç°IRP (IOÇëÇó°ü)
IrpStack = IoGetCurrentIrpStackLocation( Irp );

//µÃµ½DeviceIoControl´«À´µÄ¿ØÖÆÂë
ControlCode = IrpStack->Parameters.DeviceIoControl.IoControlCode;
//µÃµ½DeviceIoControl´«À´µÄÊäÈ뻺³åÇø³¤¶È
InputLength = IrpStack->Parameters.DeviceIoControl.InputBufferLength;
//µÃµ½DeviceIoControlµÄÊä³ö»º³åÇø³¤¶È
OutputLength = IrpStack->Parameters.DeviceIoControl.OutputBufferLength;

switch (ControlCode)
{
case IOCTL_SHAREMEMORY_GETVADDR:
try
{
UserVirtualAddress = MmMapLockedPages(Mdl, UserMode);
*((PVOID *)(Irp->AssociatedIrp.SystemBuffer)) = UserVirtualAddress;
Irp->IoStatus.Status = STATUS_SUCCESS;
Irp->IoStatus.Information = sizeof(PVOID);
}
except(EXCEPTION_EXECUTE_HANDLER){}
DbgPrint(\"in ioctl_sharememory_getvaddr.\");
break;

case IOCTL_SHAREMEMORY_SHOWCONTENT:
       DbgPrint(\"in ioctl_sharememory_showcontent.\");
DbgPrint(\"Now the shared memory is : \");
DbgPrint((char *)SystemVirtualAddress );
DbgPrint(\"\\n\");
Irp->IoStatus.Status = STATUS_SUCCESS;
Irp->IoStatus.Information = 0L;
break;
default:
break;
}
status = Irp->IoStatus.Status;
//Íê³ÉIRPÇëÇó
IoCompleteRequest(Irp, 0);
return status;
}

我运行的时候是这样：
在APP里点击一个按钮，我上面的代码开始执行。然后能弹出in driver和share memory的信息框，不过立刻softice弹出，是pagefault错误。然后应用程序就死掉了。请你看看有什么毛病？
实际上我对这些代码也不是很熟悉，没想到好不容易把收。发什么的弄好以后又出来这么个大头。你能劳烦给我讲讲么？