re: CVS commit: src/sys/opencrypto

[matthew green <mrg%eterna.com.au@localhost>]

> >> Implement in-module ref-counting, and do not allow auto-unload if there
> >> are existing references.
> >> 
> >> Note that manual unloading is not prevented.
> >> 
> >> OK christos@
> >> 
> >> XXX Also note that there is still a small window where the ref-count can
> >> XXX be decremented, and then the process/thread preempted.  If auto-unload
> >> XXX happens before that thread can return from the module's code, bad
> >> XXX things (tm) could happen.
> >
> >in this case, please simply disallow unload for this module always.
> >if the race is fixed, it can be enabled again.
> 
> I think that most module unloads suffer from this race, any ideas how to
> fix it?

phase one:  disable auto-unload.

phase two:  ???

the rest left as an exercise for the reader.  :-)