3.2 页面异常-2

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• IoPageRead()

---

IoPageRead()

/*
 * @implemented
 */
NTSTATUS
NTAPI
IoPageRead(IN PFILE_OBJECT FileObject,
           IN PMDL Mdl,
           IN PLARGE_INTEGER Offset,
           IN PKEVENT Event,
           IN PIO_STATUS_BLOCK StatusBlock)
{
    PIRP Irp;
    PIO_STACK_LOCATION StackPtr;
    PDEVICE_OBJECT DeviceObject;
    IOTRACE(IO_API_DEBUG, "FileObject: %p. Mdl: %p. Offset: %p \n",
            FileObject, Mdl, Offset);

    /* Get the Device Object */
    DeviceObject = IoGetRelatedDeviceObject(FileObject);

    /* Allocate IRP */
    Irp = IoAllocateIrp(DeviceObject->StackSize, FALSE);
    if (!Irp) return STATUS_INSUFFICIENT_RESOURCES;

    /* Get the Stack */
    StackPtr = IoGetNextIrpStackLocation(Irp);

    /* Create the IRP Settings */
    Irp->MdlAddress = Mdl;
    Irp->UserBuffer = MmGetMdlVirtualAddress(Mdl);
    Irp->UserIosb = StatusBlock;
    Irp->UserEvent = Event;
    Irp->RequestorMode = KernelMode;
    Irp->Flags = IRP_PAGING_IO |
                 IRP_NOCACHE |
                 IRP_SYNCHRONOUS_PAGING_IO |
                 IRP_INPUT_OPERATION;
    Irp->Tail.Overlay.OriginalFileObject = FileObject;
    Irp->Tail.Overlay.Thread = PsGetCurrentThread();

    /* Set the Stack Settings */
    StackPtr->Parameters.Read.Length = MmGetMdlByteCount(Mdl);
    StackPtr->Parameters.Read.ByteOffset = *Offset;
    StackPtr->MajorFunction = IRP_MJ_READ;
    StackPtr->FileObject = FileObject;

    /* Call the Driver */
    return IofCallDriver(DeviceObject, Irp);
}