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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 24D00C432C3 for ; Fri, 15 Nov 2019 22:43:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 03C182072A for ; Fri, 15 Nov 2019 22:43:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727186AbfKOWn6 (ORCPT ); Fri, 15 Nov 2019 17:43:58 -0500 Received: from correo.us.es ([193.147.175.20]:49878 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726995AbfKOWn5 (ORCPT ); Fri, 15 Nov 2019 17:43:57 -0500 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id CB9BEFB454 for ; Fri, 15 Nov 2019 23:43:53 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id BE1ADDA801 for ; Fri, 15 Nov 2019 23:43:53 +0100 (CET) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id AF6DCB8005; Fri, 15 Nov 2019 23:43:53 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id AF1B9DA3A9; Fri, 15 Nov 2019 23:43:51 +0100 (CET) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Fri, 15 Nov 2019 23:43:51 +0100 (CET) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from us.es (sys.soleta.eu [212.170.55.40]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: 1984lsi) by entrada.int (Postfix) with ESMTPSA id 7B755426CCBA; Fri, 15 Nov 2019 23:43:51 +0100 (CET) Date: Fri, 15 Nov 2019 23:43:53 +0100 X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: Arnd Bergmann Cc: y2038@lists.linaro.org, Jozsef Kadlecsik , Florian Westphal , "David S. Miller" , linux-kernel@vger.kernel.org, Eric Dumazet , netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org Subject: Re: [PATCH 5/8] netfilter: xt_time: use time64_t Message-ID: <20191115224353.hpoyzvwvawu3fq3c@salvia> References: <20191108203435.112759-1-arnd@arndb.de> <20191108203435.112759-6-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191108203435.112759-6-arnd@arndb.de> User-Agent: NeoMutt/20170113 (1.7.2) X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 08, 2019 at 09:34:28PM +0100, Arnd Bergmann wrote: > The current xt_time driver suffers from the y2038 overflow on 32-bit > architectures, when the time of day calculations break. > > Also, on both 32-bit and 64-bit architectures, there is a problem with > info->date_start/stop, which is part of the user ABI and overflows in > in 2106. > > Fix the first issue by using time64_t and explicit calls to div_u64() > and div_u64_rem(), and document the seconds issue. > > The explicit 64-bit division is unfortunately slower on 32-bit > architectures, but doing it as unsigned lets us use the optimized > division-through-multiplication path in most configurations. This should > be fine, as the code already does not allow any negative time of day > values. > > Using u32 seconds values consistently would probably also work and > be a little more efficient, but that doesn't feel right as it would > propagate the y2106 overflow to more place rather than fewer. Applied, thanks.