Subject: Re: nfs optimization and veriexec
To: None <>
From: YAMAMOTO Takashi <>
List: tech-security
Date: 11/12/2007 20:25:54
> YAMAMOTO Takashi wrote:
> >> YAMAMOTO Takashi wrote:
> >>
> >>>> Perhaps it's a good time to introduce said scope, and add an action
> >>>> to indicate whether the NFS optimization can take place. Would that
> >>>> work for you?
> >>> i'm not sure what you mean by "an action to indicate whether the
> >>> NFS optimization can take place."
> >>> do you mean to make nfs call kauth_authorize_foo with the action?
> >> Yes, but that call will only be made if Veriexec is compiled in.
> >>
> >>>> The only thing I'm wondering about is what the kernel would do in
> >>>> case Veriexec is not even compiled in... maybe just put in weak-aliased
> >>>> stubs (similar to secmodel_start() in kern/init_main.c).
> >>>>
> >>>> (perhaps having a file that is always compiled and contains weak-aliased
> >>>> always-allow stubs for when conditionally compiled in scopes are not
> >>>> compiled in is appropriate? :)
> >>> i don't understand how it matters.
> >>> do you mean a very veriexec specific scope which doesn't make sense at all
> >>> unless veriexec is compiled in?
> >> Yes.
> >>
> >> -e.
> > 
> > how is it different from #ifdef VERIEXEC?
> For your specific case, it's not that different, other than the fact
> it provides the ability to, in the future, control just that very
> optimization. (correct me if I'm wrong -- and it's likely that I am,
> given my lack of experience with NFS -- but can the optimization
> be worded as "bypass normal file creation procedure"?)
> The Veriexec scope I'm talking about is in my plans for quite a while,
> and has nothing to do with the NFS optimization -- the latter was just
> the trigger for me to bring it up and discuss whether it may be
> appropriate to introduce it, and at the same time, provide a solution
> to the NFS optimization.
> In any case, I don't object putting an #ifdef, but figured I'd share
> other ideas I have. :)
> -e.

i don't think the veriexec scope is a good idea in general
or an acceptable solution for my specific case.

can you explain why you want to make it veriexec specific?