Re: Marking ia64 psABI conformance (Re: PATCH: Support the .note.GNU-property section)

["H. J. Lu" <hjl at lucon dot org>]

On Thu, Jun 05, 2003 at 04:49:37PM +0200, Jakub Jelinek wrote:
> On Thu, Jun 05, 2003 at 07:46:04AM -0700, H. J. Lu wrote:
> > On Thu, Jun 05, 2003 at 10:11:36AM +0100, Nick Clifton wrote:
> > > Hi H.J.
> > > 
> > > > This patch implements the .note.GNU-property section I proposed. It
> > > > works on Linux/ia32 and Linux/ia64.
> > > 
> > > I would prefer holding off applying this patch until we have a use for
> > > it.  Otherwise it would just bit rot away over time.
> > > 
> > 
> > As you may know, the current gcc violates the ia64 psABI by not
> > preserving gp across function calls. The relocatable file created by
> > the current gcc may not be binary compatible with the relocatable
> > file generated by other ia64 psABI conforming compilers. The result
> > is we may get random run-time failure. We'd like to have a way to
> > detect such a condition. Here is one way to do that using the
> > .note.GNU-property section.
> 
> On the other side, IA-64 does not need PT_GNU_STACK handling, since
> its trampolines don't need executable stack.
> 

It is trivial to overwrite gflags and psflags for a backend. You just
define elf_backend_[copy|merge|print]_[target_]property. One more
benefit of my .note.GNU-property proposal.


H.J.