Re: [davidm@napali.hpl.hp.com: Re: [PATCH] i386 vsyscall DSOimplementation]

[Jim Wilson <wilson at tuliptree dot org>]

On Sat, 2003-06-14 at 21:19, H. J. Lu wrote: 
> Under what condition will the offset between 2 segments change? Even
> with shared library, I don't think the offset between 2 segments
> will change.

I dunno.  I'm not an expert with this stuff.  However, I do believe that
there are systems that will load segments and then relocate them.  If
this happens, there is no guarantee that offsets between segments will
remain the same.  This will not work if you have segrel relocs that span
segment boundaries, as your example does.  I doubt that this is a
problem for linux though.

I did say it was a technicality.  If the linux kernel wants to rely on a
feature that violates the IA-64 ABI, then that is certainly their
choice.  We should at least mention the problem to them though.  It
might be reasonable to fix the IA-64 ABI to allow this.  Or it might be
reasonable to change the linux kernel so that it doesn't do this, and
modify bfd to give an error for invalid segrel relocs like the one in
your example.

Jim