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,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 02AFAC43441 for ; Fri, 23 Nov 2018 17:39:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE0A620866 for ; Fri, 23 Nov 2018 17:39:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CE0A620866 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.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 S2440949AbeKXEYb (ORCPT ); Fri, 23 Nov 2018 23:24:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57728 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732362AbeKXEYb (ORCPT ); Fri, 23 Nov 2018 23:24:31 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 530C33084033; Fri, 23 Nov 2018 17:39:18 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-117-155.ams2.redhat.com [10.36.117.155]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 14B515D760; Fri, 23 Nov 2018 17:39:11 +0000 (UTC) From: Florian Weimer To: Rich Felker Cc: Mathieu Desnoyers , carlos , Joseph Myers , Szabolcs Nagy , libc-alpha , Thomas Gleixner , Ben Maurer , Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , Will Deacon , Dave Watson , Paul Turner , linux-kernel , linux-api Subject: Re: [RFC PATCH v4 1/5] glibc: Perform rseq(2) registration at nptl init and thread creation References: <20181121183936.8176-1-mathieu.desnoyers@efficios.com> <686626451.10113.1542901620250.JavaMail.zimbra@efficios.com> <87wop5xeit.fsf@oldenburg.str.redhat.com> <1045257294.10291.1542905262086.JavaMail.zimbra@efficios.com> <87k1l5xd33.fsf@oldenburg.str.redhat.com> <20181122171010.GH23599@brightrain.aerifal.cx> <871s7cvt1l.fsf@oldenburg.str.redhat.com> <20181123142843.GJ23599@brightrain.aerifal.cx> <1150466925.11664.1542992720871.JavaMail.zimbra@efficios.com> <20181123173019.GK23599@brightrain.aerifal.cx> Date: Fri, 23 Nov 2018 18:39:04 +0100 In-Reply-To: <20181123173019.GK23599@brightrain.aerifal.cx> (Rich Felker's message of "Fri, 23 Nov 2018 12:30:19 -0500") Message-ID: <87zhtzsngn.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Fri, 23 Nov 2018 17:39:18 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Rich Felker: > On Fri, Nov 23, 2018 at 12:05:20PM -0500, Mathieu Desnoyers wrote: >> There has been presumptions about signals being blocked when the thread >> exits throughout this email thread. Out of curiosity, what code is >> responsible for disabling signals in this situation ? Related to this, >> is it valid to access a IE model TLS variable from a signal handler at >> _any_ point where the signal handler nests over thread's execution ? >> This includes early start and just before invoking the exit system call. > > It should be valid to access *any* TLS object like this, but the > standards don't cover it well. C++ makes it undefined: Thanks, Florian