Re: [Xen-devel] Re: NPTL/TLS "emulation" idea (fwd)

[Jakub J. <ja...@re...>]

On Wed, Oct 20, 2004 at 06:27:39PM +0100, Keir Fraser wrote:
> > On Wed, Oct 20, 2004 at 12:55:22PM -0400, Rik van Riel wrote:
> > >    4. Provide an alternative libc that does the +ve accesses (which are
> > >       libc private, afaik) in another segment.  This does not break the
> > >       ABI for userland programs and -ve accesses aren't that bad when
> > >       there are no +ve accesses in the same segment.
> > 
> > No, the ABI uses -ve accesses and %gs:0 (4 bytes there), +ve accesses
> > above +4 are glibc private.
> 
> Could we duplicate %gs:0 at %gs:-4 and update the ABI? Or is the ABI
> now set in stone?

The ABI is there for several years, used e.g. in Solaris as well
and is used already in several libraries, not just glibc.
The ABI is not going to change for the sake of emulators.

	Jakub