Re: [RFA] i386 segment base support

Mark Kettenis
2010-05-20T14:41:29Z

> Date: Thu, 20 May 2010 08:54:37 -0400
> From: Daniel Jacobowitz <dan@codesourcery.com>
>
> On Thu, May 20, 2010 at 10:19:54AM +0200, Mark Kettenis wrote:
> > Sorry, but we still need to discuss what programming model you intend
> > to support before I will consider looking at diffs.
> >
> > Currently, on i386, GDB supports a fully flat 32-bit model, with one
> > small exception on platforms that support thread-local-storage. In
> > that model you can assume that all the segment bases are 0 except for
> > %gs. If that's all that people are interested in, I don't think we
> > should bother with segment bases for %cs, %ds, %es, %fs and %ss.
> >
> > If people want to support fully segmented memory in GDB, then what you
> > propose is probably not enough, at least not for 32-bit mode.
>
> This position confuses me. Isn't "very limited support for segmented
> memory" better than "no support for segmented memory"?

I'm not taking a position here. I'm trying to figure out what people
want out of this. If it is only about supporting TLS for Linux
userland binaries we can have a radically simpler solution than when
people want full fledged kernel-style segment register manipulating
code to work as well.