Re: [RFC] fix the relative jump problem on large modules

[James Bottomley <James.Bottomley@HansenPartnership.com>]

On Sat, 2010-06-19 at 19:21 -0400, John David Anglin wrote:
> > The theory was that the linker should do the right thing and not emit a
> > relocation that can't reach the boundary of the text segment (i.e. it
> > should embed a stub between the sections as it combines them).  I'll
> > have to fire up a 32 bit compile and see exactly what it thinks it's
> > doing ... I've got a nasty feeling it expects us to be able to stub
> > either at the beginning or the end, which the in-kernel loader doesn't.
> 
> See ld --stub-group-size=N option.

I was assuming that was the default, like on arm, I take it it's not?

>   GCC assumes stub sections are at
> the beginning and that the linker can insert stubs between input sections.
> Merging text sections is likely to cause problems.

Well, the theory was that ld was capable of more intelligent section
layout decisions than the in-kernel linker.  If you're saying that's not
true, then there's probably not much point to doing this.

James