From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4202 invoked by alias); 6 May 2004 21:38:09 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 4195 invoked from network); 6 May 2004 21:38:08 -0000 Received: from unknown (HELO faui10.informatik.uni-erlangen.de) (131.188.31.10) by sources.redhat.com with SMTP; 6 May 2004 21:38:08 -0000 Received: from faui1d.informatik.uni-erlangen.de (faui1d [131.188.31.34]) by faui10.informatik.uni-erlangen.de (8.9.3p3/8.1.9-FAU) with ESMTP id XAA09131; Thu, 6 May 2004 23:38:03 +0200 (CEST) From: Ulrich Weigand Received: (from weigand@localhost) by faui1d.informatik.uni-erlangen.de (8.9.3p3/8.1.6-FAU) id XAA05769; Thu, 6 May 2004 23:38:03 +0200 (CEST) Message-Id: <200405062138.XAA05769@faui1d.informatik.uni-erlangen.de> Subject: Re: Display of read/access watchpoints when HAVE_NONSTEPPABLE_WATCHPOINT To: pkoning@equallogic.com (Paul Koning) Date: Thu, 06 May 2004 21:38:00 -0000 Cc: weigand@i1.informatik.uni-erlangen.de, orjan.friberg@axis.com, kettenis@chello.nl, gdb-patches@sources.redhat.com, eliz@gnu.org, drow@false.org In-Reply-To: <16536.61374.770000.659411@gargle.gargle.HOWL> from "Paul Koning" at May 05, 2004 09:44:30 AM MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-SW-Source: 2004-05/txt/msg00161.txt.bz2 > My experience was that the old code worked if you had only a > watchpoint active, but it would produce the wrong results if you had > both watchpoints and breakpoints active. The reason was that the scan > for matching break/watch points would conclude that the target break > had happened due to a non-matching watchpoint and would proceed, > rather than break. But this error scenario should only apply to read/access watchpoints, never write watchpoints. A write watchpoint should never be misdetected ... > That doesn't seem like a good idea. Why would it be reasonable to > treat the two differently? Because a write watchpoints can be handled without hardware support to provide the address, while read/access watchpoints fundamentally cannot be. Bye, Ulrich -- Dr. Ulrich Weigand weigand@informatik.uni-erlangen.de