From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 39541 invoked by alias); 6 Dec 2016 17:48:18 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 33281 invoked by uid 89); 6 Dec 2016 17:48:15 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_PASS,URIBL_RED autolearn=ham version=3.3.2 spammy= X-HELO: relay1.mentorg.com Date: Tue, 06 Dec 2016 17:48:00 -0000 From: Joseph Myers To: Szabolcs Nagy CC: Torvald Riegel , , GNU C Library Subject: Re: [RFC][BZ #19329] high level description of pthread_create vs dlopen races In-Reply-To: <5846F3EB.2060003@arm.com> Message-ID: References: <583C7F76.3000601@arm.com> <1480965875.14990.199.camel@redhat.com> <5846F3EB.2060003@arm.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" 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) X-SW-Source: 2016-12/txt/msg00201.txt.bz2 On Tue, 6 Dec 2016, Szabolcs Nagy wrote: > meanwhile the rest of the world needs a way to detect > reentry into an as-safe library call which currently > requires as-safe tls (signal mask is not an option: > syscalls are too slow) and a way to do soft float > correctly (fenv is tls and arithmetics must be as-safe) > or just access errno (which could be made as-safe even > if tls access is not as-safe otherwise, but specifying > that correctly in the standard is more hassle than > requiring all tls access to be as-safe). errno, the powerpc soft-float floating-point environment and the libdfp soft-dfp decimal rounding mode are all initial-exec TLS (and other cases of floating-point environment are hardware registers rather than TLS variables). Does being initial-exec help? -- Joseph S. Myers joseph@codesourcery.com