From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gdb-patches-return-79451-listarch-gdb-patches=sources.redhat.com@sourceware.org>
Received: (qmail 32368 invoked by alias); 8 Mar 2011 19:39:48 -0000
Received: (qmail 32360 invoked by uid 22791); 8 Mar 2011 19:39:48 -0000
X-SWARE-Spam-Status: No, hits=-1.9 required=5.0	tests=AWL,BAYES_00,T_RP_MATCHES_RCVD
X-Spam-Check-By: sourceware.org
Received: from mail.codesourcery.com (HELO mail.codesourcery.com) (38.113.113.100)    by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 08 Mar 2011 19:39:42 +0000
Received: (qmail 21343 invoked from network); 8 Mar 2011 19:39:40 -0000
Received: from unknown (HELO scottsdale.localnet) (pedro@127.0.0.2)  by mail.codesourcery.com with ESMTPA; 8 Mar 2011 19:39:40 -0000
From: Pedro Alves <pedro@codesourcery.com>
To: Mark Kettenis <mark.kettenis@xs4all.nl>
Subject: Re: [RFA] i386-tdep.c, check target_read_memory for error.
Date: Tue, 08 Mar 2011 19:50:00 -0000
User-Agent: KMail/1.13.5 (Linux/2.6.35-27-generic; KDE/4.6.1; x86_64; ; )
Cc: gdb-patches@sourceware.org, msnyder@vmware.com, jan.kratochvil@redhat.com
References: <4D715BB0.8030506@vmware.com> <201103081858.43441.pedro@codesourcery.com> <201103081925.p28JPKb4008277@glazunov.sibelius.xs4all.nl>
In-Reply-To: <201103081925.p28JPKb4008277@glazunov.sibelius.xs4all.nl>
MIME-Version: 1.0
Content-Type: Text/Plain;  charset="iso-8859-15"
Content-Transfer-Encoding: 7bit
Message-Id: <201103081939.38165.pedro@codesourcery.com>
X-IsSubscribed: yes
Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm
Precedence: bulk
List-Id: <gdb-patches.sourceware.org>
List-Subscribe: <mailto:gdb-patches-subscribe@sourceware.org>
List-Archive: <http://sourceware.org/ml/gdb-patches/>
List-Post: <mailto:gdb-patches@sourceware.org>
List-Help: <mailto:gdb-patches-help@sourceware.org>, <http://sourceware.org/ml/#faqs>
Sender: gdb-patches-owner@sourceware.org
X-SW-Source: 2011-03/txt/msg00564.txt.bz2

On Tuesday 08 March 2011 19:25:20, Mark Kettenis wrote:
> > From: Pedro Alves <pedro@codesourcery.com>
> > Date: Tue, 8 Mar 2011 18:58:43 +0000
> > 
> > On Tuesday 08 March 2011 18:37:55, Michael Snyder wrote:
> > > @@ -1221,7 +1231,8 @@ i386_skip_noop (CORE_ADDR pc)
> > >        if (op == 0x90) 
> > >         {
> > >           pc += 1;
> > > -         target_read_memory (pc, &op, 1);
> > > +         if (target_read_memory (pc, &op, 1))
> > > +           return pc;
> > 
> > I think you're meant to return PC as it was at function
> > start.  Note the pc += 1 above.  There are other instances
> > in the patch.
> 
> Those are actually fine.  Skipping nop instructions is harmless, even
> if we get stuck somewhere in the middle.

You're right, missed that.

BTW, I noticed a bunch of read_memory_unsigned_integer/read_memory_integer
calls in these skippers/sniffers.  These functions call read_memory, which
throws.

-- 
Pedro Alves