Re: CVS commit: src/sys

[Antti Kantee <pooka%cs.hut.fi@localhost>]

On Mon Jan 19 2009 at 18:27:53 -0500, Christos Zoulas wrote:
> So how are we supposed to put hooks into the code like in rtsock.c? Do
> we use weak symbols and check if they are there? Also right now the kernfs
> code does not compile with IPSEC, so we don't have the ipsec files? How
> do we fix that?

rtsock is .. hopeless ;)

kernfs needs to support dynamic registration.

I've used weak symbols a bit with rump, but they always make me
uncomfortable.  Explicitly writing out a dynamic relationship makes
me feel better.  Unfortunately sometimes it's impossible, such as when
behaviour really depends on which libraries are linked in.

> We need to document the sanctioned way to do these things. Does using
> weak symbols work? I am guessing not, because it does not un-resolve them
> when the module unloads...

From what I remember playing with the kernel linker and weak symbols a
few weeks ago, I don't think it supports them at all.  I might have got
it wrong, though, since I didn't spend very long with it.

Technically, if weak symbols are the answer, I don't see why you couldn't
unresolve symbols: just store the weak link when you do a strong link.