[RFC] ppc64 and calling conventions

[Roland McGrath]

Frankly I don't think we are ready to commit now to saying what is useful.
There is significant work to be done and issues to be decided before glibc
will ever actually call any of your entry points.  I would recommend that
you start by getting a working vDSO in that has no interesting entry
points, just the signal trampoline code (and it doesn't really matter
whether you give that symbols or not, except perhaps to gdb).  We have the
support already there to make the trampoline unwind info available so that
you can start using it and supporting nonexecutable stacks.  

I can't recommend right now that you do anything immediately to provide any
entry points that you might feel compelled to stay compatible with later.
We just haven't ironed out exactly how such things should be tied into
libc, and until we do, all bets are off as to whether anything you choose
now is something you'll want to stick with in the long run.