On Wednesday 11 September 2002 23:26, Jamie Lokier wrote:
> Daniel Phillips wrote:
> > Really, that's not so, there are limits. 30 seconds? Whatever.
> > Remember, during this time the service provided by the module is
> > unavailable, so this is denial-of-service land. You could of
> > course put in extra code to abort the unload process on demand,
> > but, hmm, it probably wouldn't work ;-)
>
> If you're going to do it right, you should fix that denial-of-service by
> waiting until the module has finished unloading and then demand-loading
> the module again.
That doesn't make the DoS go away, it just makes it a little
harder to trigger. Anyway, one thing we could do if the rest
of the module mechanism is up to it, is know that somebody is
trying to reactivate a module that has just returned from
module_cleanup(), and immediately reactivate it instead of
freeing it, hoping to save some disk activity - if this turns
out to be a real problem, that is. The null solution is likely
the winner here.
> Ideally, those periodic "rmmod -a" calls should _never_ cause a
> denial-of-service.
Goodness no. By the way, nobody has asked me how rmmod -a is
to be implemented. Oh well.
-- Daniel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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