From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 2338 invoked by alias); 20 May 2010 14:41:29 -0000 Received: (qmail 2316 invoked by uid 22791); 20 May 2010 14:41:27 -0000 X-SWARE-Spam-Status: No, hits=-2.1 required=5.0 tests=AWL,BAYES_00,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from sibelius.xs4all.nl (HELO glazunov.sibelius.xs4all.nl) (83.163.83.176) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 20 May 2010 14:41:19 +0000 Received: from glazunov.sibelius.xs4all.nl (kettenis@localhost [127.0.0.1]) by glazunov.sibelius.xs4all.nl (8.14.3/8.14.3) with ESMTP id o4KEdVxi027120; Thu, 20 May 2010 16:39:31 +0200 (CEST) Received: (from kettenis@localhost) by glazunov.sibelius.xs4all.nl (8.14.3/8.14.3/Submit) id o4KEdTqF031135; Thu, 20 May 2010 16:39:29 +0200 (CEST) Date: Thu, 20 May 2010 14:44:00 -0000 Message-Id: <201005201439.o4KEdTqF031135@glazunov.sibelius.xs4all.nl> From: Mark Kettenis To: dan@codesourcery.com CC: teawater@gmail.com, gdb-patches@sourceware.org, dje@google.com, msnyder@vmware.com, eliz@gnu.org In-reply-to: <20100520125437.GU8410@caradoc.them.org> (message from Daniel Jacobowitz on Thu, 20 May 2010 08:54:37 -0400) Subject: Re: [RFA] i386 segment base support References: <201005200819.o4K8JseL023478@glazunov.sibelius.xs4all.nl> <20100520125437.GU8410@caradoc.them.org> Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2010-05/txt/msg00415.txt.bz2 > Date: Thu, 20 May 2010 08:54:37 -0400 > From: Daniel Jacobowitz > > 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.