From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23838 invoked by alias); 19 Feb 2015 07:17:49 -0000 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 Received: (qmail 23776 invoked by uid 89); 19 Feb 2015 07:17:49 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.3 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=unavailable version=3.3.2 X-Spam-User: qpsmtpd, 2 recipients X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Thu, 19 Feb 2015 07:17:47 +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 t1J7HcxZ009535 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 19 Feb 2015 02:17:38 -0500 Received: from blokker.wildebeest.org (ovpn-116-21.ams2.redhat.com [10.36.116.21]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t1J7HaDg013754 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 19 Feb 2015 02:17:37 -0500 Received: by blokker.wildebeest.org (Postfix, from userid 1000) id D7BA1204AE; Thu, 19 Feb 2015 08:17:35 +0100 (CET) Date: Thu, 19 Feb 2015 07:17:00 -0000 From: Mark Wielaard To: "H.J. Lu" Cc: Joel Brobecker , GCC Patches , Binutils , GDB Subject: Re: ping #3: [RFA] Add --with-libz-prefix option in config/zlib.m4 Message-ID: <20150219071735.GA2484@blokker.redhat.com> References: <20150218120841.GD23529@adacore.com> <20150218165457.GU544@vapier> <20150218194443.GW544@vapier> <1424291541.23458.28.camel@bordewijk.wildebeest.org> <1424295643.23458.30.camel@bordewijk.wildebeest.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-SW-Source: 2015-02/txt/msg00516.txt.bz2 On Wed, Feb 18, 2015 at 01:54:17PM -0800, H.J. Lu wrote: > On Wed, Feb 18, 2015 at 1:40 PM, Mark Wielaard wrote: > > On Wed, 2015-02-18 at 12:53 -0800, H.J. Lu wrote: > >> On Wed, Feb 18, 2015 at 12:32 PM, Mark Wielaard wrote: > >> > That doesn't seem like a smart default. And why is is Linux/x86 only? > >> > Shouldn't that be something that is done explicitly by a distro > >> > configuring binutils after making sure it actually is beneficial > >> > (debuginfo is often compressed in a different way, on the package/file > >> > level or with dwz). And after making sure all tools actually work with > >> > it? There are various tools that don't handle the .zdebug format like > >> > valgrind. And at least elfutils has trouble with it for ET_REL files, > >> > like kernel modules, because relocations don't actually apply anymore to > >> > the section data as is (but only after the decompression). > >> > >> Now it becomes a monthly topic: > >> > >> https://sourceware.org/ml/binutils/2015-01/msg00089.html > > > > Thanks, I hadn't seen that before. Alan Modra makes some good points in > > that thread why it is not a good change: > > https://sourceware.org/ml/binutils/2015-01/msg00135.html > > Do people agree with that? And/Or can the change be reverted for now > > till there is agreement it is a desirable default? > > > > It may not be a good idea for all targets. If you find an issue > on Linux/x86, please file a bug binutils report. The issue is that this is not something that is target architecture specific. As others have pointed out this isn't something that is target architecture-dependent. So please first get agreement on whether or not to default for the OS (or for all ELF targets or the GNU targets). Otherwise distros will have to revert on a target by target basis to get something consistent. Secondly the bug is not directly in binutils (but there might be an issue between versions compiled with/without zlib support). If .zdebug sections are left in on disk ET_REL files, like kernel modules, there is a problem for programs that don't deal with .zdebug sections (and/or relocations against them) in ET_REL files like elfutils, systemtap, debugedit, dwz, etc. Thanks, Mark