From owner-svn-src-head@freebsd.org Mon Apr 3 09:47:41 2017 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A1F21D2A728; Mon, 3 Apr 2017 09:47:41 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4916F786; Mon, 3 Apr 2017 09:47:41 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id v339lYab078473 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 3 Apr 2017 12:47:34 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua v339lYab078473 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id v339lXCK078472; Mon, 3 Apr 2017 12:47:33 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Mon, 3 Apr 2017 12:47:33 +0300 From: Konstantin Belousov To: Chagin Dmitry Cc: Bruce Evans , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r316393 - head/sys/compat/linux Message-ID: <20170403094733.GM43712@kib.kiev.ua> References: <201704020746.v327kDSN042840@repo.freebsd.org> <20170402133651.GJ43712@kib.kiev.ua> <20170402163306.GA44865@mordor.heemeyer.club> <20170403035157.X3216@besplex.bde.org> <20170402182341.GA50190@mordor.heemeyer.club> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170402182341.GA50190@mordor.heemeyer.club> User-Agent: Mutt/1.8.0 (2017-02-23) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on tom.home X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Apr 2017 09:47:41 -0000 On Sun, Apr 02, 2017 at 09:23:41PM +0300, Chagin Dmitry wrote: > On Mon, Apr 03, 2017 at 03:57:29AM +1000, Bruce Evans wrote: > > On Sun, 2 Apr 2017, Chagin Dmitry wrote: > > > > > On Sun, Apr 02, 2017 at 04:36:51PM +0300, Konstantin Belousov wrote: > > >> On Sun, Apr 02, 2017 at 07:46:13AM +0000, Dmitry Chagin wrote: > > >>> Author: dchagin > > >>> Date: Sun Apr 2 07:46:13 2017 > > >>> New Revision: 316393 > > >>> URL: https://svnweb.freebsd.org/changeset/base/316393 > > >>> > > >>> Log: > > >>> As noted by bde@ negative tv_sec values are not checked for overflow, > > >>> so overflow can still occur. Fix that. Also remove the extra check for > > >>> tv_sec size as under COMPAT_LINUX32 it is always true. > > >>> > > >>> Pointed out by: bde@ > > >>> > > >>> MFC after: 1 week > > >>> > > >>> Modified: > > >>> head/sys/compat/linux/linux_time.c > > >>> > > >>> Modified: head/sys/compat/linux/linux_time.c > > >>> ============================================================================== > > >>> --- head/sys/compat/linux/linux_time.c Sun Apr 2 07:11:15 2017 (r316392) > > >>> +++ head/sys/compat/linux/linux_time.c Sun Apr 2 07:46:13 2017 (r316393) > > >>> @@ -125,8 +125,7 @@ native_to_linux_timespec(struct l_timesp > > >>> > > >>> LIN_SDT_PROBE2(time, native_to_linux_timespec, entry, ltp, ntp); > > >>> #ifdef COMPAT_LINUX32 > > >>> - if (ntp->tv_sec > INT_MAX && > > >>> - sizeof(ltp->tv_sec) != sizeof(ntp->tv_sec)) > > >>> + if (ntp->tv_sec > INT_MAX || ntp->tv_sec < INT_MIN) > > >> This line reads as only tv_sec == INT_MAX case results in non-EOVERFLOW > > >> condition. > > >> > > > > > > should I rewrite it like: > > > > > > if (ntp->tv_sec < INT_MIN || ntp->tv_sec > INT_MAX) > > > ? > > > > I don't see the problem. Do you mean that the compiler might remove > > this code because the check is tautologically false on 32-bit natives, > > but warn too? > > I mean kib@ sentence that line 'reads like', as I'm sure that the code > is correct. > This code does not compile on 32-bit as it under COMPAT_LINUX32. I indeed mis-read the context where the checks are done, I thought that the members checked are ints. Please ignore me. > > > > > > The sizeof() comparison is even easier to evaluate at compile time. > > Perhaps it acted a hint to the compiler to not warn. > > > > Bruce > > --