From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 934B6C282D7 for ; Wed, 30 Jan 2019 21:10:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4529D218AF for ; Wed, 30 Jan 2019 21:10:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732687AbfA3VKQ (ORCPT ); Wed, 30 Jan 2019 16:10:16 -0500 Received: from relay1.mentorg.com ([192.94.38.131]:43979 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727068AbfA3VKP (ORCPT ); Wed, 30 Jan 2019 16:10:15 -0500 Received: from nat-ies.mentorg.com ([192.94.31.2] helo=svr-ies-mbx-01.mgc.mentorg.com) by relay1.mentorg.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-SHA384:256) id 1gox7b-0003bh-AT from joseph_myers@mentor.com ; Wed, 30 Jan 2019 13:10:11 -0800 Received: from digraph.polyomino.org.uk (137.202.0.90) by svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) with Microsoft SMTP Server (TLS) id 15.0.1320.4; Wed, 30 Jan 2019 21:10:08 +0000 Received: from jsm28 (helo=localhost) by digraph.polyomino.org.uk with local-esmtp (Exim 4.90_1) (envelope-from ) id 1gox7X-0004yy-Fg; Wed, 30 Jan 2019 21:10:07 +0000 Date: Wed, 30 Jan 2019 21:10:07 +0000 From: Joseph Myers X-X-Sender: jsm28@digraph.polyomino.org.uk To: Mathieu Desnoyers CC: carlos , Florian Weimer , 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 Subject: Re: [RFC PATCH glibc 1/4] glibc: Perform rseq(2) registration at C startup and thread creation (v6) In-Reply-To: <1832200535.4162.1548871426959.JavaMail.zimbra@efficios.com> Message-ID: References: <20190121213530.23803-1-mathieu.desnoyers@efficios.com> <632671842.3079.1548781059601.JavaMail.zimbra@efficios.com> <596949707.3888.1548812359874.JavaMail.zimbra@efficios.com> <1832200535.4162.1548871426959.JavaMail.zimbra@efficios.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: SVR-IES-MBX-08.mgc.mentorg.com (139.181.222.8) To svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 30 Jan 2019, Mathieu Desnoyers wrote: > #if defined (__NR_rseq) && !defined (RSEQ_SIG) > # error "UAPI headers support rseq system call, but glibc does not define RSEQ_SIG." > #endif > > Would that take care of your concerns ? That would of course need appropriate conditionals based on the most recent kernel version for which a given glibc version has been updated, so that using new kernel headers with an existing glibc release does not make the build fail (cf. the test of syscall-names.list). And being able to write such a test only solves one half of the problem - it needs to be easy to determine what value to put in that header in glibc for an architecture that's newly gained support in the kernel, *without* needing any architecture expertise. -- Joseph S. Myers joseph@codesourcery.com