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=-4.1 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 1647F1F462 for ; Fri, 14 Jun 2019 13:47:20 +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:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-type :content-transfer-encoding; q=dns; s=default; b=LgpHJI3ogt0lXTjb 3mXAnW8tJ67IeRgIt793raRPepsg5gWnPfdD70a67IJ3i78/gK+CkhyrDLQwJmS+ PsLwZ76ei4hp0LyQu/Y7Ga6hRKtZN1jsLY8yQa/8op4blHpaHd2/pVelnnjQO2a1 HfSpa16o6OCKTn0apZcizvcCw2k= 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:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-type :content-transfer-encoding; s=default; bh=IPs3puzbM2TsJZtCsJAzTJ ESXdQ=; b=AFaaUmN8fzM/gnGNzbgzqUXDRdWCwpHHUmG0MkSnfwrms6zJoQDON3 avc+qSrEEgw0lltK6lffOkEUB2/adbUDsiVFpo0oXBL4S/I2cnOlI4hNwAM++kV6 8gC5ZBwb7fXeD0PrLxcBXKYjefEonv1JmgHIJjuHqpgw8rFCyQly8= Received: (qmail 102905 invoked by alias); 14 Jun 2019 13:47:17 -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 102895 invoked by uid 89); 14 Jun 2019 13:47:17 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mail.efficios.com DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com 19F7F2517DB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=default; t=1560520034; bh=81EpfFNjP6SvW3w5jVIET8nZSw4QEAdPUWyGh9rrrk0=; h=Date:From:To:Message-ID:MIME-Version; b=WP5wmVF8o+loCPX8mYQM0wAdEPJvADvYrEjChO39wLC+vtYpIZxQuRACD3Kgpe7Zq yhLb+4GcQ7C1oJH+sDD40TqSWG3P42Q+5Pcc8M28ejSkaIRm0sg+t465+rlB++q6Gn m1uywQpEaIDmT3u+1QZqmeKgaI5D30aIo2kFFsg+8ey0ccxACsRsz2ozANcftu/sUn jB+oiHAEw5jFqmOTTOXQk/CMPgmyamBGMz5xOaH7UYn8J7FY2v6qHyeh+fBLZo3JK2 MXBEtnwG5IJbvsUUqMouiENJR5j9pJ68XHzbGN8JAzxgrFje6wyjfArbPkO+mMVa/W UdJlAmp2tJ4nw== Date: Fri, 14 Jun 2019 09:47:13 -0400 (EDT) From: Mathieu Desnoyers To: Florian Weimer Cc: carlos , Joseph Myers , Szabolcs Nagy , libc-alpha , Thomas Gleixner , Ben Maurer , Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , Will Deacon , Dave Watson , Paul Turner , Rich Felker , linux-kernel , linux-api Message-ID: <26171199.3391.1560520033825.JavaMail.zimbra@efficios.com> In-Reply-To: <87imt8tha5.fsf@oldenburg2.str.redhat.com> References: <20190503184219.19266-1-mathieu.desnoyers@efficios.com> <1190407525.3131.1560516910936.JavaMail.zimbra@efficios.com> <1085273942.3137.1560517301721.JavaMail.zimbra@efficios.com> <87d0jguxdk.fsf@oldenburg2.str.redhat.com> <1779359826.3226.1560518318701.JavaMail.zimbra@efficios.com> <87wohoti47.fsf@oldenburg2.str.redhat.com> <189377747.3315.1560519247118.JavaMail.zimbra@efficios.com> <87imt8tha5.fsf@oldenburg2.str.redhat.com> Subject: Re: [PATCH 1/5] glibc: Perform rseq(2) registration at C startup and thread creation (v10) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit ----- On Jun 14, 2019, at 3:42 PM, Florian Weimer fweimer@redhat.com wrote: > * Mathieu Desnoyers: > >> + /* Publicize rseq registration ownership. This must be performed >> + after rtld re-relocation, before invoking constructors of >> + preloaded libraries. */ >> + rseq_init (); > > Please add a comment that IFUNC resolvers do not see the initialized > value. I think this is okay because we currently do not support access > to extern variables in IFUNC resolvers. Do IFUNC resolvers happen to observe the __rseq_handled address that was internal to ld.so ? If so, we could simply initialize __rseq_handled twice: early before calling IFUNC resolvers, and after ld.so re-relocation. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com