From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32578 invoked by alias); 14 Jul 2010 18:44:46 -0000 Received: (qmail 32557 invoked by uid 22791); 14 Jul 2010 18:44:45 -0000 X-SWARE-Spam-Status: No, hits=-1.7 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; Wed, 14 Jul 2010 18:44:40 +0000 Received: (qmail 11731 invoked from network); 14 Jul 2010 18:44:38 -0000 Received: from unknown (HELO tp.orcam.me.uk) (macro@127.0.0.2) by mail.codesourcery.com with ESMTPA; 14 Jul 2010 18:44:38 -0000 Date: Wed, 14 Jul 2010 18:44:00 -0000 From: "Maciej W. Rozycki" To: David Daney cc: Thomas Schwinge , binutils@sourceware.org, Jan Kratochvil , Andrew Stubbs , gdb@sourceware.org, Nathan Sidwell Subject: Re: MIPS: 64-bit DWARF In-Reply-To: <4C3DEC14.8090601@caviumnetworks.com> Message-ID: References: <4BE16915.7080501@codesourcery.com> <20100505143213.GA4735@caradoc.them.org> <4BE187D8.4050804@codesourcery.com> <20100507132310.GA6374@host0.dyn.jankratochvil.net> <87sk431a3j.fsf@dirichlet.schwinge.homeip.net> <87fwzxvslw.fsf_-_@dirichlet.schwinge.homeip.net> <87eif6v450.fsf@dirichlet.schwinge.homeip.net> <4C3DEC14.8090601@caviumnetworks.com> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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: 2010-07/txt/msg00044.txt.bz2 On Wed, 14 Jul 2010, David Daney wrote: > > Here is the patch that I tested for (a non-HEAD version of) binutils. > > This makes prelink happy, and there are no regressions in the GDB > > testsuite. (Anything else to test?) I left in the 64-bit stuff for > > TE_IRIX, as I have no idea about it. > > How was it tested? Have you tested mips64-linux-gnu with -mabi=64? GCC switched to emitting 32-bit DWARF records on the MIPS/Linux/n64 platform a couple of years ago. GDB as of 6.8 didn't cope at all with 64-bit DWARF records that were generated for n64 binaries before the switch (for the MIPS platform, that is -- I'd expect it to work for some others, especially ones that have always been 64-bit like the Alpha) -- the usual symptom was a complete exhaustion of the stack space followed by a crash (tested natively only). I am strongly convinced GAS should follow, for consistency if nothing else, and I am rather surprised both tools were not updated at once. TE_IRIX refers to the original 64-bit DWARF stuff invented by SGI that predates DWARF-3 and differs slightly from the latter. This may perhaps be the reason of the GDB crash -- it may have this SGI variant hardcoded for the MIPS target or suchlike. Having noticed the GCC switch I have not investigated it further. The change needs to be properly tested of course to see if it does not uncover an odd bug somewhere, but in principle I consider it the right and necessary move. Maciej