From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8009 invoked by alias); 2 Sep 2013 13:19:23 -0000 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 Received: (qmail 7995 invoked by uid 89); 2 Sep 2013 13:19:23 -0000 Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 02 Sep 2013 13:19:23 +0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-5.8 required=5.0 tests=AWL,BAYES_00,KHOP_THREADED,RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r82DJHcp028269 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 2 Sep 2013 09:19:17 -0400 Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r82DJG8E029289; Mon, 2 Sep 2013 09:19:17 -0400 Message-ID: <52249053.6050103@redhat.com> Date: Mon, 02 Sep 2013 13:19:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Pierre Muller CC: gdb-patches@sourceware.org Subject: Re: [RFA] windows-nat.c: Handle ERROR_PARTIAL_COPY in windows_xfer_memory function References: <5223bb46.c6c0420a.5a41.008dSMTPIN_ADDED_BROKEN@mx.google.com> <52248978.90500@redhat.com> <000301cea7dd$17bc4af0$4734e0d0$@muller@ics-cnrs.unistra.fr> In-Reply-To: <000301cea7dd$17bc4af0$4734e0d0$@muller@ics-cnrs.unistra.fr> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-SW-Source: 2013-09/txt/msg00019.txt.bz2 On 09/02/2013 02:05 PM, Pierre Muller wrote: >>> This is not compatible with returning information that only part of the >>> request length >>> was read/written. >> >> Well, we could just change that interface to make it possible... >> >> The thing I don't like with doing this only on the native >> side, is that we're trying to get to a point where we >> can share the target backends between GDB and gdbserver: > > Well, when you look at the code inside child_xfer_memory, > you can notice that the return value of ReadProcessMemory or > WriteProcessMemory > is discarded, which means that it does behave more or less like the > new windows-nat.c code (at least in case of ERROR_PARTIAL_COPY) > for other errors, it might also return garbage... > anyhow, the calling code compares the returned value to the requested length > (LEN value) That's brittle... > so that the risk of generating a successful read_memory despite a failure > of ReadProcessMemory function is small... (the uninitialized variable done > would need to return the value LEN..) > It could of course still happen theoretically... This is really no argument for not fixing gdbserver... In fact, it's an argument _for_ fixing it. -- Pedro Alves