> One thing which is worrying me is the following:

[ excerpts of code deleted ]

> as far as I can see this is all at spl0 - I'm probably missing something
> important but this looks horribly like a potential race condition to me. Could
> someone please explain to me why it isn't, or if it is, why it isn't important.
> As far as I can see this could lead to junk being written via dangling
> pointers.

You missed the fact that the kernel isn't preemptive. That is, the two code
snippets you cited are never run intermixed.

Hope to make thinks clear.
--
ws@TooLs.DE     (Wolfgang Solfrank, TooLs GmbH) 	+49-228-985800