From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5988 invoked by alias); 26 Apr 2011 21:42:01 -0000 Received: (qmail 5971 invoked by uid 22791); 26 Apr 2011 21:42:00 -0000 X-SWARE-Spam-Status: No, hits=-1.9 required=5.0 tests=BAYES_00,MSGID_FROM_MTA_HEADER,RCVD_IN_DNSWL_NONE X-Spam-Check-By: sourceware.org Received: from blu0-omc1-s30.blu0.hotmail.com (HELO blu0-omc1-s30.blu0.hotmail.com) (65.55.116.41) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 26 Apr 2011 21:41:44 +0000 Received: from BLU0-SMTP16 ([65.55.116.9]) by blu0-omc1-s30.blu0.hotmail.com with Microsoft SMTPSVC(6.0.3790.4675); Tue, 26 Apr 2011 14:41:43 -0700 Message-ID: Received: from krystal.dyndns.org ([174.91.200.164]) by BLU0-SMTP16.phx.gbl over TLS secured channel with Microsoft SMTPSVC(6.0.3790.4675); Tue, 26 Apr 2011 14:41:42 -0700 Received: from localhost (localhost [127.0.0.1]) (uid 1000) by krystal.dyndns.org with local; Tue, 26 Apr 2011 17:41:41 -0400 id 001B6595.4DB73C15.000052C5 Date: Tue, 26 Apr 2011 21:42:00 -0000 From: Mathieu Desnoyers To: Tom Tromey CC: "Cui, Dexuan" , "'ltt-dev@lists.casi.polymtl.ca'" , "'gdb@sourceware.org'" , systemtap@sources.redhat.com, Josh Stone Subject: Re: [ltt-dev] gdb-7.2 can't build with lttng-ust-0.12 References: <1865303E0DED764181A9D882DEF65FB6931C75A5AA@shsmsx502.ccr.corp.intel.com> <1865303E0DED764181A9D882DEF65FB6931C75A5AE@shsmsx502.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: X-Editor: vi User-Agent: Mutt/1.5.18 (2008-05-17) Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2011-04/txt/msg00151.txt.bz2 * Tom Tromey (tromey@redhat.com) wrote: > >>>>> "Dexuan" == Cui, Dexuan writes: > > Mathieu> Also, we should reopen the discussion on the way the UST Markers > Mathieu> collect the registers for GDB, because the current way involves a > Mathieu> _lot_ of ugly assembly code. It should be possible to only use a > Mathieu> volatile inline asm to specify input constraints on the target marker > Mathieu> parameters, and keep the instruction pointer address that corresponds > Mathieu> to this inline asm in a section known by gdb (so gdb could use the > Mathieu> drawf info to fetch data from registers/memory). If you can ensure > Mathieu> that this would fit gdb's requirements, I could clean up the marker > Mathieu> code and we could resync the APIs together. We could also provide > Mathieu> this for UST Tracepoints in the same go, with pretty much the same > Mathieu> interface as we'd use for UST Markers. I am aware that this would > Mathieu> require change on the GDB side, but I think it's better to > Mathieu> synchronise our effort rather than to shoot at different targets. > > I am not totally clear on the proposal here. > > If this means reusing the stuff, then there are gdb patches > already submitted to fully support that; and updating the existing code > to also use it should not be very difficult. See gdb-patches from the > last month or two. Yes, the goal is to rely on sdt.h as soon as it supports a e.g. STAP_PROBEV (with variable number of args). The Josh Stone found a neat trick to do it, and I think he is preparing an updated version. The only concern here is the packaging: if we depend on sdt.h, we have to either ship it with UST, or have one more dependency on a package available for all architectures that only contain this header. Thoughts ? It's good to hear that GDB is already planning on supporting that. Thanks, Mathieu > > If instead you mean something else, it would be useful to have more > information. From your description it sounds like this may be a > different design from SDT v3; but note that SDT v2 tried to use DWARF to > access the parameters and ran into various problems. I can get details > on the failure modes if this is what you intend. > > Dexuan> Unluckily I'm pretty new to gdb and know few about this now. > Dexuan> Let me Cc the gdb mailing list for more thoughts(hope this cross-posting > Dexuan> wouldn't bother people). > > Cross-posting in cases like this is fine, even preferable. > > I don't know anything about the gdbserver bits here. It seems to me > that it would be reasonable to have gdbserver compile against various > versions of UST. > > Tom > -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com