> I think usually system calls return errno and stuff their real return
> value into a pointer.  Is that what you're doing?  

Yep, you're right, this is the problem.

> It's not clear from your earlier message.

It was not clear in my mind ;o)

-- 
Emmanuel Dreyfus.
"Le 80x86 n'est pas si complexe - il n'a simplement pas de sens"
(Mike Johnson, responsable de la conception x86 chez AMD) 
p99dreyf@criens.u-psud.fr