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=-0.8 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 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 1305AC4338F for ; Sun, 15 Aug 2021 17:12:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA8A46120F for ; Sun, 15 Aug 2021 17:12:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229493AbhHORNU (ORCPT ); Sun, 15 Aug 2021 13:13:20 -0400 Received: from mout.gmx.net ([212.227.17.21]:55349 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229453AbhHORNT (ORCPT ); Sun, 15 Aug 2021 13:13:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1629047531; bh=iVY2eT07p6wla7PUQvqOvAgRk8cL7jO3dFPhVSTv32Y=; h=X-UI-Sender-Class:Date:From:To:Cc:Subject:References:In-Reply-To; b=ULsZwXn/Km4z4/IV8PQqn/1JHQIzOohQJvC8pJkgZKz4KP5bsjbghnWfHsoPDv+8l 3Vi6Zf7Qmpw5VCDbqN2WI8rfK3jT9wjIEyW8I33UoKIcDo1HdfRF7Q9qeN9m9ClHPz /2l8zkbFzkdSo55Prjco/q2S43rX/2vIW0R3BEBs= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from titan ([79.150.72.99]) by mail.gmx.net (mrgmx105 [212.227.17.174]) with ESMTPSA (Nemesis) id 1M2f5T-1mEUCK09vT-00496y; Sun, 15 Aug 2021 19:12:11 +0200 Date: Sun, 15 Aug 2021 19:12:00 +0200 From: Len Baker To: Joe Perches Cc: Len Baker , Andy Shevchenko , Jonathan Cameron , Lars-Peter Clausen , David Laight , Kees Cook , linux-hardening@vger.kernel.org, linux-iio , Linux Kernel Mailing List Subject: Re: [PATCH v4] drivers/iio: Remove all strcpy() uses Message-ID: <20210815171200.GA103145@titan> References: <20210814135509.4500-1-len.baker@gmx.com> <20210815163639.GA97260@titan> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: X-Provags-ID: V03:K1:gQFUIsQgrrC4I0WSXEMkVtHibykSSrGVjvYOe9QxTuW1Lr82xhG nqCQtZBFia5AoGL6lAVWawASZpG51q2/UuMX/IfvjnsjHZpj1mev4QcpEccISZWQCmhcryR 7t6gqq6eC8Di9Rq0q/G6uKxvdxuDWXAQQn0o3+1SfvGgdLQQa6q1eQLekTSlixoAvU4actf vmy2+T18/07/aeC8ygpTg== X-UI-Out-Filterresults: notjunk:1;V03:K0:jCFit4HvshU=:/vU2goQu7BJanTeNIsXBy+ qR6QcjB5wzk3z8Drfaiuc2ruij/U0+9217RjNeHF27GfDkcnlll6uszYEcdZyZ1heO/09NIAz VLjjQemp7Hrgqf+bfinPbyMdlFWH3VH3iZSIv09km9JAuz/38cs8rNFxtKjT+aT2LXnDYYUC4 rnkL3Tvw7oPUAQ464vd3btbE6bZhx+p1YmAg7ZlDpAEaOTxO8lFMDb78qfCjEgQzACjJxlUft LdveSdSz3/NzfsslNpHA0n0EznUxwDGn2ULlri7EXdjQ2iJhnR6lfQbpe87uJXv2eNLCs83AR oK3b3GNhSD47/ybGQkSyEBb4YvHCq1vyyzNVgDO8fQ3IOcRlxtNPMnfpiC92OO+DOkqqJ6pO/ t3hoTKE5Jw7EzDwMiwTbK9lmlE7NthmsJYm2jaR5ZQSrHOcv/DMzEba0BLTnZMckdh5C05K/r IxyJtybHj6Ja9KudsblSZzthVMooiesSwvWDdMyFLB5/PtTBlmuvB/OkXN1Zau6dtLX8CaRYa WzOnyRHvo5l2FU8GZfDKUmyE30C9/xI1r7HOyxqWdMtz27bcqsSL0+NJt1WVaqblTGX7LAi7m BBug7swAYEwhfiSZoclCepWu2XyiJ/8pqYbejk2UiVnXE20HRx6OJG1tVTAnd2OY48tkItdfA 7XqlfSv/hAN7ZAdcmvymwQJtvNZzv7DNhvA+X5MMuVnoQ70SDJVTTNVMBM1Wjwy+g4hO/5UPc 4ov+6rTEtROGORcqHG6bjHkJRPw/PQ0VoNThszNGrogO/uChjWg07H7+H7GTJz4vaImsX9c4l oqBjayUPrBGVpzaP3RiojLol5TbPU8u+vWRJ9WklFyfq+vE1KwgLqS+fi/OuAu4zczTKv7rj/ m75q8LJYhxql0ofN7BULiMzY0w5XEN9eYGtjO8R087EwQMddWHlwta7dGDb13CYt3i1I+E9Af Jms9vlIwPUkeanS6EPnCDLOwXPTfpnbtckS6FLpg4zt1zVAiouxmUhzo02BL5+CNobCHK2gvI dg2kVWEqj5Ga2v/5gP4BTOsYVSRyO2m9mkAlkxY9WE9t0YUhE5lhHibBAnu6QToGvs5f1YGE5 j6tVefUoudILKx3qFX1pPLKRzdPoWIhzDeBsNpQqbEri1A+rJROJ1uWCA== Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org Hi, On Sun, Aug 15, 2021 at 09:58:02AM -0700, Joe Perches wrote: > On Sun, 2021-08-15 at 18:36 +0200, Len Baker wrote: > > Hi Joe, > > Hello Len. > > Don't take this advice too seriously, it's just bikeshedding > but it seems to me an unexpected use of a strcmp equivalent > in a non performance sensitive path. > > > On Sun, Aug 15, 2021 at 08:06:45AM -0700, Joe Perches wrote: > [] > > > bikeshed: > > > > > > I think this change is less intelligible than the original strcmp. > > > > So, if I understand correctly you suggest to change the above line for= : > > =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0else if (strcmp(orient, "0") =3D=3D 0) > > Yes. > > In kernel sources it's about 2:1 in favor of '!strcmp()' over 'strcmp() = =3D=3D 0' > > $ git grep -P '\!\s*strcmp\b' | wc -l > 3457 > $ git grep -P '\bstrcmp\s*\([^\)]+\)\s*=3D=3D\s*0\b' | wc -l > 1719 > > And it's your choice to use one or the other or just your V4 patch. I will increase the !strcmp() statistics ;) > > btw, according to godbolt: > > gcc -O2 doesn't call strcmp and produces the same object code as your > byte comparisons. clang 11 calls strcmp regardless of optimization leve= l. > > Thanks for the feedback, Len