Re: in-kernel linking issues

[Richard Henderson <rth@twiddle.net>]

On Fri, Nov 15, 2002 at 05:13:23AM +0100, Andi Kleen wrote:
> Richard Henderson <rth@twiddle.net> writes:
> >  (3) Alpha and MIPS64 absolutely require that the core and init allocations
> >      are "close" (within 2GB).  I don't see how this can be guaranteed with
> >      two different vmalloc calls.
> 
> In x86-64 (and I think sparc64) the modules (both data and code) also need
> to be within 2GB of the main kernel code. This is done to avoid needing
> a GOT for calls between main kernel and modules. In the old module code that
> is done with a custom module_map() function. I have not looked yet on how
> that could be implemented in the new code.

Hmm.  I guess that can be done with the two allocation hooks,
which could allocate from a special pool (as is done with the
module_map function at present).  And, as far as that goes,
could apply to Alpha and MIPS as well, if the same special
allocation is done.

Consider this point refuted, Rusty.


r~