From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 9CFB71F5AE for ; Wed, 29 Jul 2020 21:18:05 +0000 (UTC) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 987B23857C5D; Wed, 29 Jul 2020 21:18:04 +0000 (GMT) Received: from esa2.mentor.iphmx.com (esa2.mentor.iphmx.com [68.232.141.98]) by sourceware.org (Postfix) with ESMTPS id 4DAD53857C42 for ; Wed, 29 Jul 2020 21:18:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 4DAD53857C42 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=joseph_myers@mentor.com IronPort-SDR: oug7GsRT2wGdSVM2LxVWU6h1Wm6leeQXzW90nUSGwc2FWmZmyuIMaLd1FXBDH9YFkCWPC096pz VEsg/4vWcjjxCo+9P0X6EKApTHkCeLwiTC5HQHNU7IV8grM206oNJR3IgPy3CGQlUs8+peC8ss +2uZHTXtcDmU524HhUobz1R9tqozpV/xdSE9EsvLAlKF7cC1j8jl0VB/mooBFRY4uBtkVfxoXM twKvpSoU5FWpoZ3JnCGP8YDfVdsQe7dUaEG5MMY6zK5eyxHtw73Y6b9bmVb0g31tNZrAZWYF9M h2M= X-IronPort-AV: E=Sophos;i="5.75,411,1589270400"; d="scan'208";a="51434492" Received: from orw-gwy-01-in.mentorg.com ([192.94.38.165]) by esa2.mentor.iphmx.com with ESMTP; 29 Jul 2020 13:18:00 -0800 IronPort-SDR: PjJLLy38dunfr0h6/VA7FUfndfwFB3rrgid9uCEbtn0VFyVMKDb2GC3DY7g0cYBI1EScNBWxgF 2LBj1l6b8IKWYkOxtBax7wb/23usSFnT1eEhz82Cf3MSX+X6yfM7IQL56kxWXxgz7fsEGtqCU5 FZVm6IsGSVy7B0qXUboRc5ZiExdyd/LVnBcuhDx0GSea20qfY7v5aRpOwa8WuXIaL55OSv1jW1 Sf7RK3g+pwwzUADJSU8phMVkAhLxTcNicThxgcsCvxaOlysdrGMdMqesXNGkkCAU93y0RkrMHb Etk= Date: Wed, 29 Jul 2020 21:17:54 +0000 From: Joseph Myers X-X-Sender: jsm28@digraph.polyomino.org.uk To: Adhemerval Zanella Subject: Re: [PATCH 3/5] login: Add 64-bit time support In-Reply-To: <20200729205117.2925113-3-adhemerval.zanella@linaro.org> Message-ID: References: <20200729205117.2925113-1-adhemerval.zanella@linaro.org> <20200729205117.2925113-3-adhemerval.zanella@linaro.org> 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) X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alistair Francis , libc-alpha@sourceware.org Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" On Wed, 29 Jul 2020, Adhemerval Zanella via Libc-alpha wrote: > New symbols for getutent, getutent_r, getutid, getutid_r, getutline, > getutline_r, getutmp, getutmpx, getutxent, getutxid. getutxline, > pututline, pututxline, updwtmp, updwtmpx, and login are added to > all architecture but s390-32 (which already added 64-bit time support > on 32-bit ABI on glibc 2.9). I thought those structures appeared in external files (/var/run/utmp, /var/log/wtmp, /var/log/lastlog), which means changing them is problematic even with symbol versioning. Do the files keep their existing formats with the new versions of the functions translating to and from the 64-bit format when reading / writing those files? Do they get new formats with the old versions of the functions instead being the ones that translate (if so, what is the process distributions are expected to use to convert existing files on upgrade / enable old wtmp files in the old format to continue to be read by new code)? I think a detailed description of the overall strategy for maintaining compatibility with existing data in files is needed, both in the patch / patch series description and in the NEWS file describing anything required to be done on upgrade to avoid losing or corrupting data. -- Joseph S. Myers joseph@codesourcery.com