From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 2726 invoked by alias); 22 Sep 2010 22:06:20 -0000 Mailing-List: contact archer-help@sourceware.org; run by ezmlm Sender: Precedence: bulk List-Post: List-Help: List-Subscribe: List-Id: Received: (qmail 2716 invoked by uid 22791); 22 Sep 2010 22:06:19 -0000 X-SWARE-Spam-Status: No, hits=-5.7 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org To: Oleg Nesterov Cc: archer@sourceware.org, utrace-devel@redhat.com Subject: Re: gdbstub initial code, v11 References: <20100922022226.GA27400@redhat.com> From: fche@redhat.com (Frank Ch. Eigler) Date: Wed, 22 Sep 2010 22:06:00 -0000 In-Reply-To: <20100922022226.GA27400@redhat.com> (Oleg Nesterov's message of "Wed, 22 Sep 2010 04:22:26 +0200") Message-ID: User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SW-Source: 2010-q3/txt/msg00213.txt.bz2 oleg wrote: > [...] Honestly, I don't really know how do the "right thing" here. > Anyway, most probably this code will be changed. Like ptrace, ugdb > uses ->report_syscall_exit() to synthesize a trap. Unlike ptrace, > ugdb_report_signal() doesn't send SIGTRAP to itself but reports > SIGTRAP using siginfo_t we have. In any case, whatever we do, > multiple tracers can confuse each other. (It seems to me that a pure gdb report, without a synthetic self-injected SIGTRAP, should be fine.) > Next: fully implement g/G/p/P, currently I am a bit confused... > But what about features? [...] You could dig out the old "fishing plan". One demonstrated improvement was from simulating (software) watchpoints within the gdb stub, instead of having gdb fall back to issing countless single-steps with memory-fetch inquiries in between. - FChE