From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 665991F463 for ; Tue, 17 Sep 2019 13:25:02 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:subject:to:references:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; q=dns; s=default; b=Rj/jCJwu/PM/YyEK Xm3VTzeLfomZt9rlzlKVfJdqYFy5Ey/4pl9Gx6UuKNR3ZMNQ1hWbO1MqM2il4vPK VGdyZTEKaOlJ0SQo/XEZBPbf+3GX6BnlMDTaF5TiohOhL1+kbizFCgKUxeYay47x 661IvgPVDHEc/KlTIxA9zpLNNC8= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:subject:to:references:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; s=default; bh=TLB+3wTZ2WU75sg9VHpx3C mfLdw=; b=drrdeVOyclQV4mPcGZAw5XAF0HjNnEljyZED6JOJFnEv/f/uO5+GMO rPapoj3e3N5M0lu6pl/5XS8JFSvYhmy529FSC81NpncVEkdt0jacYmxg09r6c9VR ctXWKH/vBaSAPDO0BQQSb8Z6QTE7GWix5P4lEqhWwOpBF3S7ZQWvQ= Received: (qmail 114690 invoked by alias); 17 Sep 2019 13:25:00 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 114682 invoked by uid 89); 17 Sep 2019 13:25:00 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mail-qk1-f170.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=subject:to:references:from:openpgp:autocrypt:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=4MuzZvpNPt1y9yWmE1ABmdWXYSpoo2JRy5S9aOy5jsM=; b=K2nyTtBUsWkK5uIHoJs46DJUFf/Euu8h4Rv50O8xxdN9vX8CW1TJ/g80SDFXMmNg0D U8O9fr3SCB/HZ/losQXoqNKAz+nY+5dId11kpi40YzL72xqiiLmYbYo2m9T6pEmF8btp azjYqpKiiTem2dhNnaIwjRa9OsY0P/PW1XkaGODFswaqb7SiJ9zD4Jh3Mz8vw7nYK8AY fL7MpALNiWxDF5a9xR9hhcty149sFQyRYqkFpgqJrnr352La9MfG73hCaJRLs8MNm0KD FqObW2nuRfjAh5YCxvan5ymIOfKW3utAJfLGnSVwIfvhYnbQ33m/+1st0J2mUjpx+9kP y1Tw== Subject: Re: [Question] ifunc odering in ELF To: libc-alpha@sourceware.org References: <1568314984.28076.65.camel@blackberry.com> <87pnjzy75u.fsf@oldenburg2.str.redhat.com> From: Adhemerval Zanella Openpgp: preference=signencrypt Message-ID: <66583af6-6049-7f1d-0a31-a77a228cf603@linaro.org> Date: Tue, 17 Sep 2019 10:24:53 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <87pnjzy75u.fsf@oldenburg2.str.redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit On 16/09/2019 23:43, Florian Weimer wrote: > * Juchan Kim: > >> We have two ifuncs foo1 and foo2 in our library >> >> foo1 has foo1_resolver()  >> foo2 has foo2_resolver() >> >> >> foo1_resolver() { >> ... >> } >> >> foo2_resolver() { >> foo1() >> ... >> } > > IFUNC resolvers must not depend on run-time relocations. If you follow > that rule, this cannot happen. > > binutils ld sorts IFUNC relocations last, which helps, but to cover more > cases (but not all of them), run-time reordering of relocations is > needed. We have some patches for that, but my impression is that the > glibc project does not want them. Instead, we're probably going to > remove all IFUNC resolvers with relocation dependencies from glibc, and > tell others to do so as well. > That's was not my impression, I this we should to go this way iff we can't really make IFUNC reordering work on loader. From your initial work on the two-phase IFUNC relocation, which prevents us to move forward?