From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19292 invoked by alias); 6 Jul 2006 21:37:05 -0000 Received: (qmail 19274 invoked by uid 22791); 6 Jul 2006 21:37:03 -0000 X-Spam-Check-By: sourceware.org Received: from nevyn.them.org (HELO nevyn.them.org) (66.93.172.17) by sourceware.org (qpsmtpd/0.31.1) with ESMTP; Thu, 06 Jul 2006 21:37:02 +0000 Received: from drow by nevyn.them.org with local (Exim 4.54) id 1FybWt-0000Gi-4N; Thu, 06 Jul 2006 17:36:59 -0400 Date: Thu, 06 Jul 2006 21:37:00 -0000 From: Daniel Jacobowitz To: Eli Zaretskii Cc: Wu Zhou , gdb-patches@sourceware.org Subject: Re: [ppc-linux-nat]: set access flag for h/w watchpoint even if it is only read or write Message-ID: <20060706213659.GA985@nevyn.them.org> Mail-Followup-To: Eli Zaretskii , Wu Zhou , gdb-patches@sourceware.org References: <20060706132020.GB18827@nevyn.them.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.11+cvs20060403 X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2006-07/txt/msg00046.txt.bz2 On Thu, Jul 06, 2006 at 11:58:58PM +0300, Eli Zaretskii wrote: > Yes, this problem is known on x86 and elsewhere. The problem is > extremely rare, as reading and writing to the same address in the same > instruction is a hard-to-accomplish treat. Wu, could you show a > real-life example of where this matters? I thought, though I may be misremembering, that it was actually a different problem. Something like this: - We set a read watchpoint. It does not trigger on writes. - An instruction writes to the location. - GDB stops, sees that it stopped at a watchpoint at the given address, tries to determine what sort of watchpoint it was, determines that the value had changed, and ignores the read watchpoint - the value has changed since we last checked so this "must" have been a write watchpoint. Is that plausible or nonsensical? -- Daniel Jacobowitz CodeSourcery