From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753281Ab3A2P4o (ORCPT ); Tue, 29 Jan 2013 10:56:44 -0500 Received: from lennier.cc.vt.edu ([198.82.162.213]:39207 "EHLO lennier.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751894Ab3A2P4l (ORCPT ); Tue, 29 Jan 2013 10:56:41 -0500 X-Mailer: exmh version 2.8.0 04/21/2012 with nmh-1.4-dev To: Dan Carpenter Cc: Joe Perches , Greg Kroah-Hartman , Jiri Slaby , Paul Fulghum , David Howells , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [patch] TTY: synclink, small cleanup in dtr_rts() In-Reply-To: Your message of "Sun, 27 Jan 2013 23:19:47 +0300." <20130127201947.GO16282@mwanda> From: Valdis.Kletnieks@vt.edu References: <20130127194039.GA18787@elgon.mountain> <1359317078.14406.12.camel@joe-AO722> <20130127201947.GO16282@mwanda> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1359474915_2191P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Tue, 29 Jan 2013 10:55:16 -0500 Message-ID: <9561.1359474916@turing-police.cc.vt.edu> X-Mirapoint-Received-SPF: 198.82.161.152 auth3.smtp.vt.edu Valdis.Kletnieks@vt.edu 2 pass X-Junkmail-Status: score=10/50, host=zidane.cc.vt.edu X-Junkmail-Signature-Raw: score=unknown, refid=str=0001.0A02020A.5107F0E7.0039,ss=1,re=0.000,fgs=0, ip=0.0.0.0, so=2011-07-25 19:15:43, dmn=2011-05-27 18:58:46, mode=single engine X-Junkmail-IWF: false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --==_Exmh_1359474915_2191P Content-Type: text/plain; charset="us-ascii" Content-Id: <9446.1359474907.1@turing-police.cc.vt.edu> On Sun, 27 Jan 2013 23:19:47 +0300, Dan Carpenter said: > Yeah. I think it would be, but adding bitflags together instead of > doing bitwise ORs is very common as well. The fact it's common doesn't mean it's good programming practice, or even correct. Consider: #define F_FOO 0x01 #define F_BAR 0x02 #define F_BAZ 0x04 unsigned int flags = F_FOO; ... flags |= F_BAR; Now some time later, another code path does this: flags += F_FOO; If it was another |, it would be a no harm no foul class of bug. But how long is it going to take you to figure out who set F_BAZ? I wonder if there's a way to write a coccinelle patch to find places where we do arithmetic operations on bitmasks.... --==_Exmh_1359474915_2191P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iQIVAwUBUQfw4wdmEQWDXROgAQLg3g/8DWhxyP0rsFHav/81uCMSTkGKsyac8wI6 T9E/WBDECTwJBqanOukJyieIEs2yTz5h2Yk6MEh8jCiXBykIIi9hvbS6dZu1Citf XgYCnkyr0wEQqC1DOLrh/hTm246R3CO5Hbbx8s8te1eGstINkS8ka4rES7Z6R6b2 Ya1avL0zKC4tFYCek5mNsDIT+HKIIboB9mu+K4HfhJZHX/PVSizujfYLETHP3ZhY O70RCu6kxs5ROfLwjkLbQGnWCM/GzvZNqRAi/GHM8QX5NMogN7/CtT9F9EmOV1WR h+hGX2j9aNwaWVw2WHJNQcp2jauqfcAtMqHEiGTXTjfTJMfeaUIsgz0nUvl20D5y 9Y7bsPM/JmYbq4E7y00/iNR7Gz9WOWc/gb2LEvvPzT/P0SNTLSiHXV5fHR2H7QDo q+q9rMeuoisPsMN0t6+CO4ObdjvRNZW1TUfl+MBPbRDSk7c/BWNLOrk8EHPFjD88 Qqd3oxYn9Sy9toHHjfxBmHc+ep17tLHafaFQO9J9iCbgYwWW2rIddcq/skcGolRM fYIPT6gil6tm1zt5jXxNOhK/jLBm4tCOkbiZdlsrPtvEBOHiarHRHfx7r63FbmOk W+AznoCeemburE4FaS7hqGMxeOtWP97MR4CHYoMWi66iTSe36t+X/7UmZunZqDqc 3gXq1O7jWpI= =hJOs -----END PGP SIGNATURE----- --==_Exmh_1359474915_2191P--