Re: [rfa] Attach vsyscall support for GNU/Linux

Mark Kettenis
2004-11-01T22:13:04Z

Date: Mon, 25 Oct 2004 18:44:37 -0400
From: Andrew Cagney <cagney@gnu.org>

Thos funny little diagrams are UML isn't it?

It needs to be changed so more like:

SYMBOL
/|\
|
FRAME <>----- FUNCTION <>------ UNWINDER

and have the FUNCTION provide:

- signal trampoline?

I think this is wrong. It's probably true that functions that are
used as signal trampolines in traditional UNIX systems are only usable
as such, this is not true for interrupt handlers. On i386 systems you
can write interrupt handlers that are also usable as trap handlers.
Where interrupt handlers are sigtramp-like, trap handlers are musch
more normal. This kind of attributes depend more on the context and
thereforeit is more logical to put them in the frame. I think the
same is true for the unwinder.

That said, it is perfectly reasonable to let the frame inherit some of
these attributes from the function.

Mark