From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13964 invoked by alias); 2 Sep 2013 14:09:18 -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 13949 invoked by uid 89); 2 Sep 2013 14:09:17 -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 14:09:17 +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-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r82E9BqQ017770 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 2 Sep 2013 10:09:11 -0400 Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r82E9A4c013773; Mon, 2 Sep 2013 10:09:11 -0400 Message-ID: <52249C06.1020100@redhat.com> Date: Mon, 02 Sep 2013 14:09:00 -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] gdbserver/win32-low.c: Check Read/WriteProcessMemory return value (followup to [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> <52249053.6050103@redhat.com> <522494dc.297a420a.6ab0.6047SMTPIN_ADDED_BROKEN@mx.google.com> <522497AF.8080800@redhat.com> <52249a22.42bd420a.28f1.722cSMTPIN_ADDED_BROKEN@mx.google.com> In-Reply-To: <52249a22.42bd420a.28f1.722cSMTPIN_ADDED_BROKEN@mx.google.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-SW-Source: 2013-09/txt/msg00026.txt.bz2 On 09/02/2013 03:00 PM, Pierre Muller wrote: >>> What about this patch, >>> it still does not allow to really return the number of bytes read or >>> written, >>> but at least it checks correctly if the API calls succeeded. >> >> No, as long as the read_memory/write_memory interfaces do not >> support partial transfers, we should only return true if the >> all of LEN was transferred. Otherwise, things like: >> >> static int >> gdb_read_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len) >> { >> ... >> { >> res = read_inferior_memory (memaddr, myaddr, len); >> done_accessing_memory (); >> >> return res == 0 ? len : -1; >> } >> } >> >> will behave incorrectly in the ERROR_PARTIAL_COPY scenario... > > This is still done in win32_{read/write}_inferior_memory which are the two > only callers of the static child_xfer_memory function in win32-low.c > Thus the aim was to narrow the behavior gap between > windows-nat.c windows_xfer_memory function > and the win32-low.c child_xfer_memory function, > without (for now) changing anything to the beghavior of gdbserver, > as guaranteed by the > static int > win32_write_inferior_memory (CORE_ADDR memaddr, const unsigned char *myaddr, > int len) > { > return child_xfer_memory (memaddr, (char *) myaddr, len, 1, 0) != len; > } > > code... > > The only thing I changed is that child_xfer_memory returns the correct > amount of read/written memory or -1 if an error, other than > ERRO_PARTIAL_COPY, occurred. > Thus I think that your answer is missing the intermediate > win32_{read/write}_inferior_memory level. > Ah, indeed. Why the different styles in gdb's and gdbserver patches, though? gdb: > + if (!success && lasterror == ERROR_PARTIAL_COPY && done > 0) > + return done; > + else > + return success ? done : TARGET_XFER_E_IO; gdbserver: > + if (success) > + return done; > + else > + { > + if (lasterror == ERROR_PARTIAL_COPY && done > 0) > + return done; > + else > + return -1; > } We should be able to compare the functions and see at a glance they are almost duplicates. With the different styles, it's not immediately obvious. Can you make the gdbserver code look like gdb's? Thanks, -- Pedro Alves