Re: CVS commit: src/usr.bin/config

[Antti Kantee <pooka%homeworld.netbsd.org@localhost>]

On Thu, Oct 30, 2014 at 11:14:50AM +0900, Masao Uebayashi wrote:
> On Thu, Oct 30, 2014 at 10:51 AM, Christos Zoulas <christos%astron.com@localhost> wrote:
> > In article <20141030012621.0982E9A%cvs.netbsd.org@localhost>,
> > Masao Uebayashi <source-changes-d%NetBSD.org@localhost> wrote:
> >
> > Re: constructors/destructors:
> >
> > Using them will create a portability constraint on elf. This has
> > the implication that rump will not work on some platforms.
> 
> Could you show me an example failure senario?  What do you propose instead?
> 
> I heard that rump fixed linkset problem using .ctors/.dtors.

I heard something different.

A toolchain problem was fixed by using __attribute__((constructor))
to reach the contents of link sets in userspace dynamically linked
environments where generating __start/__stop was not possible.
Regular link sets are still preferred, as they require less magic
from the runtime.

Is there a problem rototilling config is going to solve over what
is possible with the existing mechanism (*)?  The problem TODO lists
is "random ELF sections (with potentially long names) in the final
kernel".  Is that a problem?

*) you probably also heard that rump kernels have constructors with
priority levels, implemented using link sets