From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29152 invoked by alias); 19 Feb 2015 13:52:32 -0000 Mailing-List: contact binutils-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: binutils-owner@sourceware.org Received: (qmail 28955 invoked by uid 89); 19 Feb 2015 13:52:30 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=2.7 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,KAM_FROM_URIBL_PCCC,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=no version=3.3.2 X-Spam-User: qpsmtpd, 2 recipients X-HELO: mail-ob0-f180.google.com Received: from mail-ob0-f180.google.com (HELO mail-ob0-f180.google.com) (209.85.214.180) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Thu, 19 Feb 2015 13:52:28 +0000 Received: by mail-ob0-f180.google.com with SMTP id vb8so14305506obc.11; Thu, 19 Feb 2015 05:52:26 -0800 (PST) MIME-Version: 1.0 X-Received: by 10.202.191.194 with SMTP id p185mr2820328oif.128.1424353946471; Thu, 19 Feb 2015 05:52:26 -0800 (PST) Received: by 10.76.134.102 with HTTP; Thu, 19 Feb 2015 05:52:26 -0800 (PST) In-Reply-To: <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> <20150219071735.GA2484@blokker.redhat.com> Date: Thu, 19 Feb 2015 13:52:00 -0000 Message-ID: Subject: Re: ping #3: [RFA] Add --with-libz-prefix option in config/zlib.m4 From: "H.J. Lu" To: Mark Wielaard Cc: Joel Brobecker , GCC Patches , Binutils , GDB Content-Type: text/plain; charset=UTF-8 X-IsSubscribed: yes X-SW-Source: 2015-02/txt/msg00270.txt.bz2 On Wed, Feb 18, 2015 at 11:17 PM, Mark Wielaard wrote: > 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). As I said before, I don't think it will happen any time soon. > 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 Please stop spreading your FUD about kernel modules. If you find a problem with kernel modules, please open a binutils bug report. > .zdebug sections (and/or relocations against them) in ET_REL files > like elfutils, systemtap, debugedit, dwz, etc. I opened a bug against elfutils: https://bugzilla.redhat.com/show_bug.cgi?id=807053 It shouldn't be be too hard to fix. We fixed it in readelf. -- H.J.