From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5708 invoked by alias); 21 Oct 2010 20:43:19 -0000 Received: (qmail 5696 invoked by uid 22791); 21 Oct 2010 20:43:19 -0000 X-SWARE-Spam-Status: No, hits=-2.1 required=5.0 tests=AWL,BAYES_00,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mail.codesourcery.com (HELO mail.codesourcery.com) (38.113.113.100) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 21 Oct 2010 20:43:11 +0000 Received: (qmail 5476 invoked from network); 21 Oct 2010 20:43:09 -0000 Received: from unknown (HELO caradoc.them.org) (dan@127.0.0.2) by mail.codesourcery.com with ESMTPA; 21 Oct 2010 20:43:09 -0000 Date: Thu, 21 Oct 2010 20:43:00 -0000 From: Daniel Jacobowitz To: Ulrich Weigand Cc: gdb-patches@sourceware.org, rearnsha@arm.com, matthew.gretton-dann@arm.com Subject: Re: [rfc/rfa] Use ARM exception tables as GDB unwinder Message-ID: <20101021204306.GU8337@caradoc.them.org> References: <20101021184229.GR8337@caradoc.them.org> <201010212029.o9LKTWpN013394@d12av02.megacenter.de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201010212029.o9LKTWpN013394@d12av02.megacenter.de.ibm.com> User-Agent: Mutt/1.5.20 (2009-06-14) 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 X-SW-Source: 2010-10/txt/msg00341.txt.bz2 On Thu, Oct 21, 2010 at 10:29:32PM +0200, Ulrich Weigand wrote: > Right, for C code there should be no problem. The problems I've been > seeing all come from *assembler* source files using the DO_CALL macro. > This gets CFI correct, but doesn't create any unwind records ... Oh.... yes, we could move that out of line for ARM too. I don't like the solution much though, because it lengthens all syscall backtraces unnecessarily. We're getting into the point where backtraces using the ARM unwinder are not useful for GDB because they're flow-insensitive. But if all the callers of DO_CALL don't contain any other calls, we have the option to record the ip = r7 save as if the syscall is the only possible 'call site'. -- Daniel Jacobowitz CodeSourcery