Re: [PATCH v3 07/20] winebus.sys: Add Linux udev bus

[Thomas Faber]

> +NTSTATUS WINAPI common_pnp_dispatch(DEVICE_OBJECT *device, IRP *irp)
> +{
> +    NTSTATUS rc = STATUS_NOT_SUPPORTED;

You generally want to initialize this with irp->IoStatus.Status.
For requests the bus driver doesn't support, it needs to return
whatever the drivers higher up the stack decided.
E.g. IRP_MN_QUERY_DEVICE_RELATIONS might be handled by a bus driver FDO
above, in which case it will likely set the status to success -- and
lower-level drivers need to propagate this status unless they have
specific reason to override it.

This is the reason for the requirement to initialize IoStatus to
STATUS_NOT_SUPPORTED when sending the IRP.
> +    IO_STACK_LOCATION *irpsp = IoGetCurrentIrpStackLocation(irp);
> +
> +    switch(irpsp->MinorFunction)
> +    {
> +        case IRP_MN_QUERY_DEVICE_RELATIONS:
> +            TRACE("IRP_MN_QUERY_DEVICE_RELATIONS\n");
> +            break;
> +        case IRP_MN_QUERY_ID:
> +        {
> +            TRACE("IRP_MN_QUERY_ID\n");
> +            break;
> +        }
> +        case IRP_MN_QUERY_CAPABILITIES:
> +            TRACE("IRP_MN_QUERY_CAPABILITIES\n");
> +            break;
> +    }
> +    IoCompleteRequest( irp, IO_NO_INCREMENT );
> +    return rc;
> +}
> +
> +DWORD check_bus_disabled(UNICODE_STRING *registry_path)
> +{
> +    OBJECT_ATTRIBUTES attr;
> +    HANDLE key;
> +    DWORD disabled = 0;
> +    static const WCHAR disabledW[] = {'D','i','s','a','b','l','e','d',0};
> +    static const UNICODE_STRING disabled_str = {sizeof(disabledW) - sizeof(WCHAR), sizeof(disabledW), (WCHAR*)disabledW};
> +
> +    InitializeObjectAttributes(&attr, registry_path, OBJ_CASE_INSENSITIVE, NULL, NULL);

This is another case for OBJ_KERNEL_HANDLE. You basically want this by
default in kernel code, unless you specifically intend to pass this
handle to an application.
> +    if (ZwOpenKey(&key, KEY_ALL_ACCESS, &attr) == STATUS_SUCCESS)
> +    {
> +        DWORD size;
> +        KEY_VALUE_PARTIAL_INFORMATION info;
> +
> +        if (ZwQueryValueKey(key, &disabled_str, KeyValuePartialInformation, &info, sizeof(info), &size) == STATUS_SUCCESS)

Your 'info' structure isn't large enough to hold DWORD
data, since the 'Data' member is a one byte array.
> +        {
> +            disabled = *(DWORD*)&info.Data;
> +        }
> +
> +        ZwClose(key);
> +    }
> +
> +    return disabled;
> +}