From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 58643 invoked by alias); 5 Mar 2020 11:54:16 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 58634 invoked by uid 89); 5 Mar 2020 11:54:14 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-10.0 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.1 spammy= X-HELO: mx0a-001b2d01.pphosted.com Subject: Re: [PATCH] S390: Remove backchain-based fallback and use generic backtrace.c. To: Florian Weimer Cc: libc-alpha@sourceware.org References: <20200304150330.3054553-1-stli@linux.ibm.com> <87tv343zyt.fsf@oldenburg2.str.redhat.com> From: Stefan Liebler Date: Thu, 05 Mar 2020 11:54:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <87tv343zyt.fsf@oldenburg2.str.redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit x-cbid: 20030511-0020-0000-0000-000003B0BB95 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20030511-0021-0000-0000-00002208F6C0 Message-Id: <3ed89cad-b841-4004-2586-ebd8620ba417@linux.ibm.com> X-SW-Source: 2020-03/txt/msg00106.txt On 3/4/20 4:24 PM, Florian Weimer wrote: > * Stefan Liebler: > >> After recent discussions: >> - "[PATCH] s390: Remove backchain-based fallback from backtrace" >> https://www.sourceware.org/ml/libc-alpha/2020-02/msg00287.html >> >> - "Re: [PATCH 07/11] s390: Implement backtrace on top of " >> https://www.sourceware.org/ml/libc-alpha/2020-02/msg00637.html >> >> We've checked and decided to remove the backchain: >> We don't know of any environments without libgcc. Thus the backchain >> unwinder is not used. If somebody builds with -mbackchain and without >> fasynchronous-unwind-tables and has libgcc installed, then the >> libgcc unwinder is called but not the backchain-based fallback. >> >> This step allows to get rid of the s390x specific backtrace.c files at all. >> Furthermore the now used debug/backtrace.c version has some more >> advantages: >> - Free all resources if necessary. (libc_freeres_fn) >> - Remove NULL address above _start. >> - Check whether we make any progress while getting addresses. > > Looks good to me. Thanks for doing this. > > Florian > Committed. Thanks, Stefan