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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 CFB2DECE564 for ; Wed, 19 Sep 2018 16:37:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 843F42150B for ; Wed, 19 Sep 2018 16:37:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 843F42150B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732641AbeISWQX (ORCPT ); Wed, 19 Sep 2018 18:16:23 -0400 Received: from relay1.mentorg.com ([192.94.38.131]:49215 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727675AbeISWQX (ORCPT ); Wed, 19 Sep 2018 18:16:23 -0400 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 1g2fTr-0003g7-HT from joseph_myers@mentor.com ; Wed, 19 Sep 2018 09:37:35 -0700 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, 19 Sep 2018 17:37:32 +0100 Received: from jsm28 (helo=localhost) by digraph.polyomino.org.uk with local-esmtp (Exim 4.90_1) (envelope-from ) id 1g2fTn-0007qw-G1; Wed, 19 Sep 2018 16:37:31 +0000 Date: Wed, 19 Sep 2018 16:37:31 +0000 From: Joseph Myers X-X-Sender: jsm28@digraph.polyomino.org.uk To: Mathieu Desnoyers CC: Carlos O'Donell , Florian Weimer , Thomas Gleixner , Ben Maurer , Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , Will Deacon , Dave Watson , Paul Turner , , , Subject: Re: [RFC PATCH] glibc: Perform rseq(2) registration at nptl init and thread creation In-Reply-To: <20180919144438.1066-1-mathieu.desnoyers@efficios.com> Message-ID: References: <20180919144438.1066-1-mathieu.desnoyers@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-01.mgc.mentorg.com (139.181.222.1) 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, 19 Sep 2018, Mathieu Desnoyers wrote: > Here is a rough prototype registering rseq(2) TLS for each thread > (including main), and unregistering for each thread (excluding > main). "rseq" stands for Restartable Sequences. A final patch would need to add documentation and tests and a NEWS entry and fix various coding style issues. > diff --git a/nptl/Versions b/nptl/Versions > index e7f691da7a..7316c2815d 100644 > --- a/nptl/Versions > +++ b/nptl/Versions > @@ -275,6 +275,7 @@ libpthread { > mtx_init; mtx_lock; mtx_timedlock; mtx_trylock; mtx_unlock; mtx_destroy; > call_once; cnd_broadcast; cnd_destroy; cnd_init; cnd_signal; > cnd_timedwait; cnd_wait; tss_create; tss_delete; tss_get; tss_set; > + __rseq_abi; __rseq_refcount; That's the GLIBC_2.28 section, but 2.28 is already out. New symbols would need to go in GLIBC_2.29 or later (and the ABI test baselines would all need updating). > diff --git a/sysdeps/unix/sysv/linux/rseq.h b/sysdeps/unix/sysv/linux/rseq.h This looks like it's coming from the Linux kernel. Can't the relevant uapi header just be used directly without copying into glibc (with due care to ensure that glibc still builds if the kernel headers used for the build are too old - you need such conditionals anyway if they don't define the relevant syscall number)? -- Joseph S. Myers joseph@codesourcery.com From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joseph Myers Subject: Re: [RFC PATCH] glibc: Perform rseq(2) registration at nptl init and thread creation Date: Wed, 19 Sep 2018 16:37:31 +0000 Message-ID: References: <20180919144438.1066-1-mathieu.desnoyers@efficios.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Return-path: In-Reply-To: <20180919144438.1066-1-mathieu.desnoyers@efficios.com> Sender: linux-kernel-owner@vger.kernel.org To: Mathieu Desnoyers Cc: Carlos O'Donell , Florian Weimer , Thomas Gleixner , Ben Maurer , Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , Will Deacon , Dave Watson , Paul Turner , libc-alpha@sourceware.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org List-Id: linux-api@vger.kernel.org On Wed, 19 Sep 2018, Mathieu Desnoyers wrote: > Here is a rough prototype registering rseq(2) TLS for each thread > (including main), and unregistering for each thread (excluding > main). "rseq" stands for Restartable Sequences. A final patch would need to add documentation and tests and a NEWS entry and fix various coding style issues. > diff --git a/nptl/Versions b/nptl/Versions > index e7f691da7a..7316c2815d 100644 > --- a/nptl/Versions > +++ b/nptl/Versions > @@ -275,6 +275,7 @@ libpthread { > mtx_init; mtx_lock; mtx_timedlock; mtx_trylock; mtx_unlock; mtx_destroy; > call_once; cnd_broadcast; cnd_destroy; cnd_init; cnd_signal; > cnd_timedwait; cnd_wait; tss_create; tss_delete; tss_get; tss_set; > + __rseq_abi; __rseq_refcount; That's the GLIBC_2.28 section, but 2.28 is already out. New symbols would need to go in GLIBC_2.29 or later (and the ABI test baselines would all need updating). > diff --git a/sysdeps/unix/sysv/linux/rseq.h b/sysdeps/unix/sysv/linux/rseq.h This looks like it's coming from the Linux kernel. Can't the relevant uapi header just be used directly without copying into glibc (with due care to ensure that glibc still builds if the kernel headers used for the build are too old - you need such conditionals anyway if they don't define the relevant syscall number)? -- Joseph S. Myers joseph@codesourcery.com