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=-3.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 3EAC5C43461 for ; Fri, 11 Sep 2020 10:52:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3E32221EE for ; Fri, 11 Sep 2020 10:52:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="lTWOLJJU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725768AbgIKKwX (ORCPT ); Fri, 11 Sep 2020 06:52:23 -0400 Received: from mout.gmx.net ([212.227.17.22]:44027 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725710AbgIKKwV (ORCPT ); Fri, 11 Sep 2020 06:52:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1599821537; bh=4mRT3yUpUdwMrkefLslPaenmtqLYGk/SPbvq8bTP6pM=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To:References; b=lTWOLJJUeQcmQsVHzt4tBOgFyaEIedr17BnMxGXiIJglxtG0Y5WHEB1PTwQyVtYeN o26Mlfzu+IzDYI8iC3oUTLVfC3BWqGVJCgBjotgKccJo6DJk5aXcRr7LU8bvgslOP1 NWQvR7iy3Fgd/X/qvA7lst09hZUuPYnTti5l5AB4= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from waterstation.localnet ([217.83.97.121]) by mail.gmx.com (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MwQTF-1kZAxA2Bi1-00sPfr; Fri, 11 Sep 2020 12:52:17 +0200 From: Florian Evers To: linux-gpio@vger.kernel.org Cc: Kent Gibson , Bartosz Golaszewski Subject: Re: [libgpiod] Integer overflow in C++ binding on 32bit systems causes wrong event timestamps Date: Fri, 11 Sep 2020 12:52:11 +0200 Message-ID: <4594456.31r3eYUQgx@waterstation> Organization: http://www.florian-evers.de In-Reply-To: References: <2572959.mvXUDI8C0e@waterstation> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart4265285.LvFx2qVVIh"; micalg="pgp-sha512"; protocol="application/pgp-signature" X-Provags-ID: V03:K1:SekJqeECkfy3WpbklyPVwPzSrBW6wFSFp7hnWJ9LtVBCG0GaZtm xsu7NIiW84YFg8F0+XTsQqALspLabX+r3gbSKIPQriuNybsjmY0Vzg5cEl6qWIoCdpd8lnD O4o1pZI+f1hv1nH7ai/DK9Vh4WNBlJaS24SpI/ZuQOffL4+sXka/iLLRF14sT5PcRw0sQEd 587pfVtpNVAd9GM4qelUQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:WRGfSozXDVM=:9Ker8Pp0oe4kMvhW83AVov QqDjPf5M1o1o6c2Her5b39iby7GFrqM+utQStb++6ldwFDf66OxcspBd2ge7NXrXLuv//cT22 argBab7eAL9DAf49rpcF0H/w+I2T3SK8+77Kkhq26Pg/x4NS1r4C9wv+RgSCetKQoqe/loY4Z pOqHHp/OsOkrjPbeacXGwUg6ug7YgmNRWjReGccyObpK1Ff5Wtz+ql6iYp62GULRz+zET20Cr McwfQ25wtY+i0jQbOIBuwVr/KLQF/Kxxo2MoVOqs9Q4UKEM4b/HTTONvehkywS76B5GXZUx0E lRK35UDFPYv4KhfmZCOYhqTbN0HH9fiWs8q/sMSy65mrUrWkNdRH1zHYRMg6QZPDExloV1aP9 gnoKk3wrY0uJFUAjPWT3wbD7RP+EDphnuilq42dia8G/vY7Y0XhBayiJ9OCVvVs+vyHcrAvVl 44MYgawm/OU+jLTkLjfOy4YjBpVvLTK4BvO//nwqSL47ELwiWZ+yK/HSmPaIfhHPcR36cwlE4 HNR50wPaYsDKc9v9SR3P67+VdkaGHySYAwknFhrSsCjHZ+OLRgte7PF/aXjZP21wNY6HmUdvL X9F1LXtAdd1xIsCaI7pgIRkt8WvChzRawxE1sshjrs1z4rC7mMIVO5a4SKH1PyPZshLnGb1Vr I020d2YQTqeeYMvWaeKM5mdzUSdnJPmu7nYIy2rFTrjrVjITts4LGewp0Ci5G3rsCPeFFto74 nkhhWtrv6Qh0W/OBDb0oeYV9qtDX17/kcDmVSRGyqTzTfvl0S3EDjHz6x62gbsc6kRo+SUVim orMYzrTXMzy1DPyX+OSoFnaKlbrwbY1G/wxx+9bNvIcwtDVs87bzsnUh7y2f9YmecCLxnsQJH xZsKQOxmWXEW0R2l2PmImSVKlczL8mG5m1KA9cnibQK0C2bcHxa99lRw9CL7f/fx9XJHVXlau LLlqXjrD7LafrVY2veIndfoRMlltPOcs36nkyeI7kTYCROGMJvZ9gDD8aQf7qzSp+t+adRLPs 840PLqo1xCVaFkfdOcbBb3Jq+g+cfJ9EHCXx0jqnmyz4WOz8MrY2CgHASXUOj+us6XcUoKDLN g+AsyOYHy2cC4vJkH1SNF20DhjRzwpwqHVy+5ZP+yeT2do5KwXWIkgqDHnnLNKJVhWvSaKFJ6 1hOgrpIGvz/zoZ6NGycnKRoofG4AEAcYgtphYiw/sc8coGxcXYnM84BgpaahyJ5/yZHL33wlV +tsbLRYfQDfkVCW9Xa/llEZP8jaWRv8xgzcAEoA== Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org --nextPart4265285.LvFx2qVVIh Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="UTF-8"; protected-headers="v1" From: Florian Evers To: linux-gpio@vger.kernel.org Cc: Kent Gibson , Bartosz Golaszewski Subject: Re: [libgpiod] Integer overflow in C++ binding on 32bit systems causes wrong event timestamps Date: Fri, 11 Sep 2020 12:52:11 +0200 Message-ID: <4594456.31r3eYUQgx@waterstation> Organization: http://www.florian-evers.de In-Reply-To: References: <2572959.mvXUDI8C0e@waterstation> Hi, thank you very much for the patch. Your approach to use std::chrono direct= ly is far better than my proposal to use a simple cast! I tested it on my platform and the use of std::chrono does not cause the overflow anymore. G= reat! Regards, Florian Am Mittwoch, 9. September 2020, 10:05:14 CEST schrieb Bartosz Golaszewski: > On Sun, Sep 6, 2020 at 6:52 PM Florian Evers wrot= e: > > Hello, > > > > I found a bug in the c++ bindings of libgpiod that affects 32bit syste= ms. > > > > Observation: > > > > Only the c++ bindings lib is affected. For input events, the time stam= p > > delivered in the event object is wrong. Instead of providing a complet= e > > "system time", it delivers time stamps of of a range "-2.1"...+2.1 sec= onds > > (which relates to the time stamp range of a signed 32bit value, in > > nanoseconds). > > > > Cause: > > > > The bug is in line 219 of file "/tree/bindings/cxx/line.cpp": > > > > event.ts.tv_nsec + (event.ts.tv_sec * 1000000000)); > > > > "event.ts.tv_sec" is of type signed long, which is 32 bit on my device= . > > Thus, that multiplication to convert total seconds of a system time to > > nanoseconds causes an overflow. > > > > Fix: > > > > There should be a cast to uint64_t before the multiplication. > > > > Thank you for fixing this! > > > > Regards, > > Florian > > Hi Florian, > > thanks for the report! I see Kent already sent a fix - could you test > it on your setup? > > Thanks in advance, > Bartosz Golaszewski --nextPart4265285.LvFx2qVVIh Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. Content-Transfer-Encoding: 7Bit -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEhKFNjXl3cTz1YyjaJLtLMH/ftD8FAl9bVtsACgkQJLtLMH/f tD9p8BAAj5xVDpGBnaNlUxLuAruEl6p4VXnLzal6HyOHZ3ytIZ7YQ5HYCCqRCcI7 U9QXtbVwdkzfjQNdM+1d5KcdoQ5zo0Cy6Sz4oE94sLhHaD83G/QxO03y0PSyBq7g yvxB7EwJcXiR46UnT0pr7bBaEY2fzu0Ll5+/nn32q+8S0kVRgAu3HYty5QCdq7Wn UJ3pv0c0zGZdvQHW01Nw4zYsTH3bknddC/v9/7cnjNlA+0zgW5wY78PjK9AMCZli 2D61ulKpjBLWA+2RpNfgE1dpDaZxZEI/fO7eJLWBcMTkHbUSdBfqIp5dTAN8HPSD WnCKIl9n0bcUZ93Tz1BpJ/UqbQzgNDzxmHqp+X62DDbI9+101CPbOKIMj5yj86Re glWuixDm3hM5hx2BHI08Bwtgghjl87tfVMAcIbNYok+l8+U4IaZotSX/lFa0AH1r hW9r4HNoQWV67mAFCwVjzX+WC1FQrpaS47L/HzedHHGNBN72E9/IE43rv+ZORr/R LD2WDIQ1GxH+4y2ToatAVy+ELqzyDXzaUSboI11CqLlN8qBG5AekYfD2oNKhpMTh 6whxfHA2gd9E72toY5QUPDhISlyzjqYJHA2kG11r8YMLvmWUqBpKeKf3ivaWoZmk USwHOft9VnCFKSh5aJQFDxZ3s3fSzwPh0UxEfYD1JRvSkE+Tuz4= =ZyJB -----END PGP SIGNATURE----- --nextPart4265285.LvFx2qVVIh--