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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C05C9EB64DD for ; Thu, 17 Aug 2023 11:38:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350217AbjHQLhk convert rfc822-to-8bit (ORCPT ); Thu, 17 Aug 2023 07:37:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350320AbjHQLhd (ORCPT ); Thu, 17 Aug 2023 07:37:33 -0400 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BF27E4F for ; Thu, 17 Aug 2023 04:37:31 -0700 (PDT) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with both STARTTLS and AUTH (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-208-gwuNGtgYP1ytLiWlQdQCzA-1; Thu, 17 Aug 2023 12:37:29 +0100 X-MC-Unique: gwuNGtgYP1ytLiWlQdQCzA-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Thu, 17 Aug 2023 12:37:25 +0100 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Thu, 17 Aug 2023 12:37:25 +0100 From: David Laight To: "'Jiri Slaby (SUSE)'" , "gregkh@linuxfoundation.org" CC: "linux-serial@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "Nathan Chancellor" , kernel test robot Subject: RE: [PATCH] tty: gdm724x: use min_t() for size_t varable and a constant Thread-Topic: [PATCH] tty: gdm724x: use min_t() for size_t varable and a constant Thread-Index: AQHZ0B87nDgSkZkjFECy+iNTKj/JmK/uXXfg Date: Thu, 17 Aug 2023 11:37:25 +0000 Message-ID: References: <20230816085322.22065-1-jirislaby@kernel.org> In-Reply-To: <20230816085322.22065-1-jirislaby@kernel.org> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: Jiri Slaby (SUSE) > Sent: Wednesday, August 16, 2023 9:53 AM > > My thinking was that ulong is the same as size_t everywhere. No, size_t > is uint on 32bit. So the below commit introduced a build warning on > 32bit: > .../gdm724x/gdm_tty.c:165:24: warning: comparison of distinct pointer types ('typeof (2048UL) *' (aka > 'unsigned long *') and 'typeof (remain) *' (aka 'unsigned int *')) > > To fix this, partially revert the commit (remove constants' suffixes) > and switch to min_t() in this case instead. > .... > - size_t sending_len = min(MUX_TX_MAX_SIZE, remain); > + size_t sending_len = min_t(size_t, MUX_TX_MAX_SIZE, remain); It would be slightly safer to use: min(remain, (size_t)MAX_TX_MAX_SIZE); since that maintains the type check. (It is also nicer to put the constant second.) David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)