I've found a very interesting link after some more investigations and web research : http://www-128.ibm.com/developerwork...ux.html#N10083

There are unfortunately some issues left :
  1. For some reasons (possibly to allow it to make use of shared components), this custom destructor is called before libraries unloading so segfaults still occurs unless I call abort() which is IMHO quite bad, even though harmless...
  2. Using the "standard" _fini() entry point seems to work better since the segfault disappears but any debug output placed in it (via printf, qDebug, whatever...) does not show up and I suppose that in this case libraries are not unloaded at all because this entry point is AFAIK, just like new/delete operators, a substitution to existing symbols available in C/C++ runtime...
  3. How portable is this solution???