IOCTL驱动程序SystemBuffer始终为NULL [英] IOCTL Driver SystemBuffer always NULL

问题描述

我有一个简单的结构，想传递给驱动程序。以下是该结构：

I have a simple struct which I would like to pass to my driver. Here is the struct:

typedef struct readStruct
{
  ...
} ReadStruct, *pRreadStruct;

这是我的用户模式应用程序：

Here is my usermode application:

DWORD dwReturn;
readStruct reader{ ... };

WriteFile(hDriver, (LPCVOID)&reader, sizeof(ReadStruct), &dwReturn, NULL);

这是我的驱动程序代码，它始终将NULL返回给readStruct。我在做什么错？

Here is my driver code, it always returns NULL to the readStruct. What am I doing wrong?

PIO_STACK_LOCATION pIoStackIrp = NULL;
pRreadStruct readStruct;

pIoStackIrp = IoGetCurrentIrpStackLocation(Irp);

DbgPrintEx(0, 0, "WriteBufferedIO\n");

if (pIoStackIrp)
{
    readStruct = (pRreadStruct)Irp->AssociatedIrp.SystemBuffer;
    if (readStruct)
    {
        // this is the place I never get into
        if (readStruct->ReadSize)
        {
            ReadMemOutputClient(readStruct);
        }
    }
}

推荐答案

DO_BUFFERED_IO 标志应在 DeviceObject-> Flags 的DriverEntry中设置。

DO_BUFFERED_IO flag should be set in DriverEntry in DeviceObject->Flags.

感谢用户@ RbMm指出了这一点。

Thanks to user @RbMm for pointing this out.

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