The Linux kernel currently does not clear the direction flag before
calling a signal handler, whereas the x86/x86-64 ABI requires that.

Linux had this behavior/bug forever, but this becomes a real problem
with gcc version 4.3, which assumes that the direction flag is
correctly cleared at the entry of a function.

This patches changes the setup_frame() functions to clear the
direction before entering the signal handler.
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NH. Peter Anvin <hpa@zytor.com>