From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17992 invoked by alias); 8 Feb 2011 18:45:33 -0000 Received: (qmail 17891 invoked by uid 22791); 8 Feb 2011 18:45:28 -0000 X-SWARE-Spam-Status: No, hits=-4.7 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 08 Feb 2011 18:45:22 +0000 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 p18IjKfH000489 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 8 Feb 2011 13:45:20 -0500 Received: from patootie.office.frob.com ([10.3.113.7]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p18IjKGC027546; Tue, 8 Feb 2011 13:45:20 -0500 Received: from magilla.sf.frob.com (magilla.office.frob.com [198.49.250.228]) by patootie.office.frob.com (Postfix) with ESMTP id 7A4AC47B0; Tue, 8 Feb 2011 10:45:19 -0800 (PST) Received: by magilla.sf.frob.com (Postfix, from userid 5281) id D39A21807D1; Tue, 8 Feb 2011 10:45:21 -0800 (PST) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: Roland McGrath To: Mark Wielaard Cc: systemtap@sourceware.org, "K.Prasad" Subject: Re: Failures with exelib.exp testcase (was Re: minutes 2010-08-19) In-Reply-To: Mark Wielaard's message of Tuesday, 8 February 2011 14:13:35 +0100 <1297170815.3956.34.camel@springer.wildebeest.org> References: <20110119120045.GA2431@in.ibm.com> <1898521794.32834.1295479440812.JavaMail.root@zmail01.collab.prod.int.phx2.redhat.com> <20110120011852.1C1041822E9@magilla.sf.frob.com> <1295521862.4118.5.camel@springer.wildebeest.org> <20110120185339.6FF851807D2@magilla.sf.frob.com> <1295651779.3049.15.camel@springer.wildebeest.org> <20110202121440.GB3524@in.ibm.com> <1296651551.4270.34.camel@springer.wildebeest.org> <20110203050358.GA2488@in.ibm.com> <1296728173.3341.7.camel@springer.wildebeest.org> <20110203123353.GC2488@in.ibm.com> <1296737077.3341.22.camel@springer.wildebeest.org> <20110203185926.19226180954@magilla.sf.frob.com> <1297170815.3956.34.camel@springer.wildebeest.org> Message-Id: <20110208184521.D39A21807D1@magilla.sf.frob.com> Date: Tue, 08 Feb 2011 18:45:00 -0000 X-IsSubscribed: yes Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2011-q1/txt/msg00219.txt.bz2 > I see your point, but do we really need a runtime test? Can't we just > have a check when reading in the elf file symbols, that just looks > whether or not there is an .odp section? To clarify, "runtime" means "runtime of the translator". So you are not suggesting doing a check in a different phase than what I said, just using a different method of analyzing the user binary in question. Why is it that you would prefer looking for an .odp section to looking at the machine the binary is built for? In general, ELF sections are not supposed to be a primary mechanism for anything after final-link time. It's a general rule in ELF that any time you are basing something on a section name, you are doing it wrong. It's also always kosher for the link to have used a linker script that combined several sections together, etc. The section name ".opd" is not part of the ppc64 ABI. What is formally said in the ABI is that the symbol name for a function (which I read to mean any STT_FUNC symbol) that does not begin with a dot is the address of the function descriptor. Anyway, it is far simpler to check the header for .e_machine == EM_PPC64 than to look for a particular section name. Thanks, Roland