From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20951 invoked by alias); 6 Sep 2013 02:03:06 -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 20938 invoked by uid 89); 6 Sep 2013 02:03:05 -0000 Received: from relay1.mentorg.com (HELO relay1.mentorg.com) (192.94.38.131) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 06 Sep 2013 02:03:05 +0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL,BAYES_00,FROM_12LTRDOM,RDNS_NONE,SPF_HELO_FAIL autolearn=no version=3.3.2 X-HELO: relay1.mentorg.com Received: from svr-orw-fem-01.mgc.mentorg.com ([147.34.98.93]) by relay1.mentorg.com with esmtp id 1VHlO0-0006m9-RL from Yao_Qi@mentor.com for gdb-patches@sourceware.org; Thu, 05 Sep 2013 19:03:00 -0700 Received: from SVR-ORW-FEM-03.mgc.mentorg.com ([147.34.97.39]) by svr-orw-fem-01.mgc.mentorg.com over TLS secured channel with Microsoft SMTPSVC(6.0.3790.4675); Thu, 5 Sep 2013 19:03:00 -0700 Received: from qiyao.dyndns.org.dyndns.org (147.34.91.1) by svr-orw-fem-03.mgc.mentorg.com (147.34.97.39) with Microsoft SMTP Server id 14.2.247.3; Thu, 5 Sep 2013 19:02:59 -0700 From: Yao Qi To: Subject: [PATCH 0/3] Trust readonly sections if target has memory protection Date: Fri, 06 Sep 2013 02:03:00 -0000 Message-ID: <1378432920-7731-1-git-send-email-yao@codesourcery.com> MIME-Version: 1.0 Content-Type: text/plain X-IsSubscribed: yes X-SW-Source: 2013-09/txt/msg00193.txt.bz2 Hi, When option "trust-readonly-sections" was introduced in this patch http://www.sourceware.org/ml/gdb-patches/2002-01/msg00711.html, there was the discussion to turn it on in default. However, we didn't do that because we have a concern that bad or buggy program may modify the code on the non-memory protected system. On the other hand, it is highly recommended to turn this on in remote debugging. I am wondering if we can teach GDB to trust read-only sections if it knows the target system has memory protection. For some targets, such as linux, we know they do have memory protection. This is what this patch series tries to do. This change improves GDB's out-of-box performance. I wrote a micro-benchmark to disassemble GDB in GDB in remote debugging (native-gdbserver) on x86-linux, and collect the time usage and the number of 'm' packets, /wo patch /w patch time usage : 0.44s 0.10 number of 'm' : 43157 4 As we can see, the number of RSP 'm' packet is reduced dramatically, and the time usage is reduced to some extent. In my experiment, GDBserver is running natively, so connection speed is quite fast. In some slow connections, the improvement will be more. This patch series only teach GDB to trust readonly sections on GNU/Linux targets. Some ancient Windows targets don't have memory protection, so we can't let GDB to rust readoly sections on mingw and cygwin target. *** BLURB HERE *** Yao Qi (3): set trust-readonly-sections off in test cases Trust readonly sections if target has memory protection Linux has memory protection. gdb/NEWS | 4 ++++ gdb/arch-utils.c | 7 +++++++ gdb/arch-utils.h | 2 ++ gdb/doc/gdb.texinfo | 11 +++++++++-- gdb/gdbarch.c | 24 ++++++++++++++++++++++++ gdb/gdbarch.h | 6 ++++++ gdb/gdbarch.sh | 3 +++ gdb/linux-tdep.c | 10 ++++++++++ gdb/target.c | 28 ++++++++++++++++++++-------- gdb/testsuite/gdb.base/break-always.exp | 4 ++++ gdb/testsuite/gdb.mi/mi-fill-memory.exp | 5 +++++ 11 files changed, 94 insertions(+), 10 deletions(-) -- 1.7.7.6