From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by sourceware.org (Postfix) with ESMTP id A77E43894C05 for ; Tue, 27 Apr 2021 15:09:18 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A77E43894C05 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-449-6yZ9aTJ6PqeOSXsV9BT8lQ-1; Tue, 27 Apr 2021 11:09:16 -0400 X-MC-Unique: 6yZ9aTJ6PqeOSXsV9BT8lQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4D0B61008061; Tue, 27 Apr 2021 15:09:14 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-113-20.ams2.redhat.com [10.36.113.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id ED58E19714; Tue, 27 Apr 2021 15:09:12 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella via Libc-alpha Cc: Tulio Magno Quites Machado Filho , Paul E Murphy , Adhemerval Zanella Subject: Re: [PATCH] powerpc: Remove backtrace implementation References: <20210212170941.1786380-1-adhemerval.zanella@linaro.org> <878s7ti4m0.fsf@oldenburg.str.redhat.com> <90d1d0e5-a31e-fbac-ead0-7f76f2645cd9@linaro.org> <87sg5n3g04.fsf@linux.ibm.com> <87blcbx91u.fsf@oldenburg.str.redhat.com> <20210226173909.nikuk5bohko2clqj@work-tp> <57f96ee4-7586-de09-2234-ad09c347be84@linux.ibm.com> <87y2djzk1a.fsf@linux.ibm.com> <12ac2270-c3af-a364-ad12-367220991d06@linaro.org> Date: Tue, 27 Apr 2021 17:09:40 +0200 In-Reply-To: <12ac2270-c3af-a364-ad12-367220991d06@linaro.org> (Adhemerval Zanella via Libc-alpha's message of "Thu, 15 Apr 2021 17:44:18 -0300") Message-ID: <87eeevn4qz.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-6.6 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Apr 2021 15:09:29 -0000 * Adhemerval Zanella via Libc-alpha: > On 15/04/2021 11:42, Tulio Magno Quites Machado Filho wrote: >> Paul E Murphy via Libc-alpha writes: >> >>> Ping? This seems like a beneficial change. Using the unwind >>> information makes for a much more robust backtrace with other languages >>> which support C bindings but do not use the same ABI (specifically >>> calling to and from go code in C). >>> >>> Should we instead turn the existing ppc backtrace into a compat symbol? >>> This seems like it would address Tulio's issue with older binaries. >> >> If we do this, we'll never be able to remove the old implementation, which was >> Adhemerval's goal. >> I particularly agree that duplicated code should be removed and I believe it >> would be helpful if libgcc had the fallback code. >> > > As before, I don't think this is a ABI breaker and making powerpc > align with other architecture simplifies the code and align the > expectation. > > And afaik all projects that do require fast unwinder do it themselves > (libsanitizer for instance) instead. I criticized this change before, but I'm now neutral, or maybe even slightly in favor. Please ignore what I said/wrote before. Thanks, Florian