From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29563 invoked by alias); 11 Feb 2008 11:03:57 -0000 Received: (qmail 29552 invoked by uid 22791); 11 Feb 2008 11:03:55 -0000 X-Spam-Check-By: sourceware.org Received: from mx-1.enea.se (HELO mx-1.enea.se) (192.36.1.70) by sourceware.org (qpsmtpd/0.31) with ESMTP; Mon, 11 Feb 2008 11:03:29 +0000 Received: from mx-2.enea.se ([172.21.1.82]) by mx-1.enea.se with Microsoft SMTPSVC(6.0.3790.1830); Mon, 11 Feb 2008 12:03:26 +0100 Received: from [127.0.0.1] ([172.16.140.117]) by mx-2.enea.se over TLS secured channel with Microsoft SMTPSVC(6.0.3790.3959); Mon, 11 Feb 2008 12:03:26 +0100 Message-ID: <47B02B7D.40204@enea.se> Date: Mon, 11 Feb 2008 11:03:00 -0000 From: Stefan Bylund User-Agent: Mozilla Thunderbird 1.0.7 (Windows/20050923) MIME-Version: 1.0 To: gdb@sourceware.org Subject: Does GDB 6.7.1 for PowerPC require the framepointer register for backtracing? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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: 2008-02/txt/msg00056.txt.bz2 Hi, We recently upgraded from GDB 6.3 to GDB 6.7.1 and noticed that for PowerPC we can longer get a backtrace in certain cases. The problem is that when we initially attach to an existing process on a remote target, only the PC and SP registers are available. This worked fine with GDB 6.3 when doing a backtrace. However, GDB 6.7.1 fails when doing a backtrace in this case, and it seems that it tries to use the framepointer register (R31) for doing the backtrace and since this register is not available (i.e. it has value 0 in GDB's perspective), the backtrace fails. Does GDB 6.7.1 requires the framepoint register (R31) for doing a backtrace? I have also noticed that if I don't install the dwarf2_frame_sniffer() and rs6000_adjust_frame_regnum() functions in rs6000_gdbarch_init() in rs6000-tdep.c, the backtrace works again even if the framepointer register is not available. However, I'm not sure exactly why... Is it safe to omit these two functions? Regards, Stefan -- --------------------------------- Stefan Bylund Senior Software Engineer Enea Skalholtsgatan 9, Box 1033, SE-164 21 Kista, Sweden Direct: +46 8 50 71 43 25 Mobile: +46 709 71 43 25 stefan.bylund@enea.com www.enea.com --------------------------------- Enea - Embedded for Leaders ---------------------------------