Re: Possible incorrect usage of STACKALIGN in kern_exec

[Martin Husemann <martin%duskware.de@localhost>]

On Tue, Jan 24, 2012 at 08:21:42PM +0100, Paul Fleischer wrote:
> Is the usage of STACKALIGN indeed incorrect in this situation, or am I
> missing the big picture?

I stumbled across this when revamping execve1 for posix_spawn recently.

The intention seems to be to align the stack on a 8 byte boundary
(where arm usualy only requires 4 byte alignment). I did not dig in the
ARM ABI docs deep enough to see why this would be needed.

However, the current implementation seems to be broken - the macro works
on the stack pointer but not on a length variable, as you noted.

Can anyone explain why arm would need 8 byte alignment?

Martin