Sys V and Mac OS X ABI

From: David Bélanger (dbelan2_at_cs.mcgill.ca)
Date: 08/23/03 

Date: 22 Aug 2003 18:50:33 -0700

>From the documentation, Mac OS X ABI has a red zone, a zone below the
stack pointer that is safe to write up to 224 bytes.

The Sys V convention (use by Linux) does not mention this red zone.
So I guess, space below the stack pointer cannot be used. Could
someone confirm this?

Also, if I were to use space below the stack pointer, could this lead
to some problem? For example, if the OS does a task switch or if the
process receive a signal? Or does these use a separate stack and it
would still be safe?

David