From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 114422 invoked by alias); 3 Apr 2017 21:23:32 -0000 Mailing-List: contact elfutils-devel-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Post: List-Help: List-Subscribe: Sender: elfutils-devel-owner@sourceware.org Received: (qmail 114388 invoked by uid 89); 3 Apr 2017 21:23:29 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Checked: by ClamAV 0.99.2 on sourceware.org X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.9 required=5.0 tests=BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=no version=3.3.2 spammy=his, paper X-Spam-Status: No, score=-0.9 required=5.0 tests=BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=no version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on sourceware.org X-Spam-Level: X-HELO: mx1.redhat.com DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 29771EEF3C Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=jan.kratochvil@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 29771EEF3C Date: Mon, 03 Apr 2017 21:23:00 -0000 From: Jan Kratochvil To: Milian Wolff Cc: elfutils-devel@sourceware.org, Mark Wielaard , Ulf Hermann Subject: Re: frame unwinding patches Message-ID: <20170403212325.GA21599@host1.jankratochvil.net> References: <1487201610-8381-1-git-send-email-mark@klomp.org> <3915502.JGE1jdPxOT@milian-kdab2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3915502.JGE1jdPxOT@milian-kdab2> User-Agent: Mutt/1.8.0 (2017-02-23) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 03 Apr 2017 21:23:29 +0000 (UTC) X-SW-Source: 2017-q2/txt/msg00005.txt.bz2 On Mon, 03 Apr 2017 11:00:03 +0200, Milian Wolff wrote: > I just got a report from a colleague. As-is, elfutils would fail to unwind > from the following location in his application: > > 0x1137ca4 > > With the x86_64 patch applied, he got a proper backtrace: S/he has something wrong with the compiler. With -fasynchronous-unwind-tables frame pointer unwinding is never needed and gcc defaults to -fasynchronous-unwind-tables on x86_64. This is why I haven't implemented it originally as it only paper overs the real problem and it leads to unreliable backtraces in longterm. Jan