Received: by 2002:ad5:474a:0:0:0:0:0 with SMTP id i10csp2663561imu; Fri, 23 Nov 2018 12:43:24 -0800 (PST) X-Google-Smtp-Source: AJdET5euiMfUdvfCUUH3DtMIoZvOI6KtYBofNE4yQPb7yXNVOLj2z/YZ76YbRY3jatz7QotRTnZ7 X-Received: by 2002:a62:9683:: with SMTP id s3mr17456104pfk.60.1543005804748; Fri, 23 Nov 2018 12:43:24 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1543005804; cv=none; d=google.com; s=arc-20160816; b=MLO1GOkXk3uJ/Ey/OF00GzVGlWe/tfmz3Sun+yBmbi8vsIOmcyjjC26viiGb5nuCYG +Ez3heUscHh7PKdqxLWJ8vxuqQAA4YZrwNaBvzY67ES+F73/+CAIJdOd2GJAU7opbfax vo2hQFl0vHW5fZx1omXnWPJBrd7jwoMDedpGFun9C4gh1K52QDpqhMENQdiGwncng+q3 b08RAteDsC9100bm3P1RZJh9smMcNB35A/fsCBxDYUCmkeYqVSnnjQRXOLdFNH0hLMl7 UxW7ZwC/nTdFalbyIwqje0aql/bo4m0ROj8VHBgKBlDRACKEBbemSSSVN4t4imOAokLV Xsig== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=PoyIfLAhXnLVnJGpfoUkuvmfCGB+PltV/UXJnBIIVBM=; b=c2XEZM1+vZSnYYeRS0zyT2Icc0H/s5plOFDodrABPJIJ47rRCF4qLIJnrOhlxa8Utc neJy9cOt3IU8+QR7VOMbXADcM9KNqkgRLKrPct4Lf0rS253cAGY6L9Iq5PjCaRlIuRWK bTIncB5i+LOt699L0Ui0Da9uCLELXuSBIqOynA6rsfvMFbQRpPhqewinRefQKe9UBbyu ZOsaOEh1rBoBiFDsG0Sa/7fm5T+2b1olzMTX8xWG14JqBTk2ZOQe8xfNAi3Qh1vvxrAp ClvkL6KfmmhKo+OOcVwa2BVjMFO4BLBcSR8LfhMR6hLs5MafiQHw9ybajcVEayu7ldfK ghAg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id d14si54580267pgn.390.2018.11.23.12.43.10; Fri, 23 Nov 2018 12:43:24 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437471AbeKWBQc (ORCPT + 99 others); Thu, 22 Nov 2018 20:16:32 -0500 Received: from 216-12-86-13.cv.mvl.ntelos.net ([216.12.86.13]:58344 "EHLO brightrain.aerifal.cx" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2395565AbeKWBQb (ORCPT ); Thu, 22 Nov 2018 20:16:31 -0500 Received: from dalias by brightrain.aerifal.cx with local (Exim 3.15 #2) id 1gPq5L-0004ig-00; Thu, 22 Nov 2018 14:36:03 +0000 Date: Thu, 22 Nov 2018 09:36:03 -0500 From: Rich Felker To: Mathieu Desnoyers Cc: Carlos O'Donell , Florian Weimer , Joseph Myers , Szabolcs Nagy , libc-alpha@sourceware.org, Thomas Gleixner , Ben Maurer , Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , Will Deacon , Dave Watson , Paul Turner , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org Subject: Re: [RFC PATCH v4 1/5] glibc: Perform rseq(2) registration at nptl init and thread creation Message-ID: <20181122143603.GD23599@brightrain.aerifal.cx> References: <20181121183936.8176-1-mathieu.desnoyers@efficios.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181121183936.8176-1-mathieu.desnoyers@efficios.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 21, 2018 at 01:39:32PM -0500, Mathieu Desnoyers wrote: > Register rseq(2) TLS for each thread (including main), and unregister > for each thread (excluding main). "rseq" stands for Restartable > Sequences. Maybe I'm missing something obvious, but "unregister" does not seem to be a meaningful operation. Can you clarify what it's for? Rich