Messages in this thread | | | Subject | Re: [patch] ppp-2.2f/2.3.x, glibc 2, and Linux 2.x | Date | Wed, 30 Jul 1997 09:25:07 -0400 | From | Horst von Brand <> |
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Richard Henderson <rth@cygnus.com> said: > "Albert D. Cahalan" <acahalan@cs.uml.edu> wrote: > > Some applications must interface directly to the kernel. > > (arpd, kerneld, various network tools...) > > How can they work if header files are incompatible?
> They supply their own. Witness modutils. There's really no other way > to live with multiple kernel trees, and the interface _cannot_ change > so quickly as to keep the kernel headers and the application headers > continually out of sync. Otherwise you break binaries right and left > and no one likes that either.
Not very good... and in the modutils case mostly to be able to use an outdated, broken interfase. I know, I've been hacking on this and related stuff some.
> > This is crazy I think.
> Straw men all. At issue is > > (1) The desire to provide surgically clean namespaces for > ISO C, POSIX, and XPG4.
OK, but that's mostly for _application_ programs. Stuff like modutils et al have no chance at all to work elsewhere, so portability is moot.
> (2) We don't want to worry about what kernel's headers are > installed so that things work properly.
OK.
> (3) Linus doesn't want to be prevented from some particular > cleanup because of what it might do to libc.
Very true.
> (4) The desire to present a constant binary interface in the > face of a number of planned kernel changes.
To whom? kernel-dependent stuff like modutils, ifconfig, &c just can't be done fully that way.
There is the kernel itself, programs closely tied to the kernel (such as modutils) that _have_ to get a peek under the hood to have any chance of surviving when stuff in the kernel changes, and regular application programs. For the last category I fully agree.
> We've been over and over this issue. Userland programs not > using kernel headers is the only sensible solution. This is > not just some bogus rule of thumb I came up with on the spur > of the moment.
There is userland, kernel sea and systems shore ;-) -- Dr. Horst H. von Brand mailto:vonbrand@inf.utfsm.cl Departamento de Informatica Fono: +56 32 654431 Universidad Tecnica Federico Santa Maria +56 32 654239 Casilla 110-V, Valparaiso, Chile Fax: +56 32 797513
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