config(1) ioconf doesn't seem good enough for pseudo-devices?

[Paul Goyette <paul%whooppee.com@localhost>]

We have a fairly large number of device driver modules which use the 
(undocumented?) "ioconf" statement in config(1) to generate the various 
data structures needed by the config(9) mechanisms.  This seems to work 
just fine for "real" devices, but for pseudo-devices the generated files 
don't quite work as expected.

As an example, we have src/sys/modules/crypto/crypto.ioconf

        ioconf crypto

        include "config/files"

        pseudo-device crypto

The generated file contains

        ...
        static struct cfdriver * const cfdriver_ioconf_crypto[] = {
                NULL
        };

        #define NORM FSTATE_NOTFOUND
        #define STAR FSTATE_STAR

> > >         static struct cfdata cfdata_ioconf_crypto[] = {
> > >             /* driver     attachment   unit state loc   flags pspec */
> > >             { NULL,       NULL,           0, 0,    NULL,      0, NULL }
> > >         };

        static const struct cfattachinit cfattach_ioconf_crypto[] = {
                { NULL, NULL }
        };

The problem arises when one attempts to pass the struct cfdata [] to 
config_attach_pseudo().  config_attach_pseudo() passes its argument to 
config_devalloc() which dereferences the .cf_driver member which is used 
as an argument to config_cfdriver_lookup().  Since the .cf_driver is 
NULL, we trap and panic.

So, is this a bug in config's ioconf processing?  Or are my expectations 
of passing the generated cfdata to config_attach_pseudo invalid?


Side comment: Is it really necessary for config/ioconf to really 
generate 300+ lines of *_iattrdata[] related to devices/attributes not 
otherwise referenced in the ioconf device tree?


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