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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04746C433F5 for ; Tue, 12 Oct 2021 08:05:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D752060F92 for ; Tue, 12 Oct 2021 08:05:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232541AbhJLIHG convert rfc822-to-8bit (ORCPT ); Tue, 12 Oct 2021 04:07:06 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.85.151]:50304 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234729AbhJLIHC (ORCPT ); Tue, 12 Oct 2021 04:07:02 -0400 Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-26-lK0fUTS6Owec_tU20_b4LA-1; Tue, 12 Oct 2021 09:04:59 +0100 X-MC-Unique: lK0fUTS6Owec_tU20_b4LA-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Tue, 12 Oct 2021 09:04:58 +0100 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.023; Tue, 12 Oct 2021 09:04:58 +0100 From: David Laight To: 'Heiko Carstens' CC: Andy Shevchenko , "linux-s390@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Vasily Gorbik , Christian Borntraeger Subject: RE: [PATCH v1 1/1] s390: Use string_upper() instead of open coded variant Thread-Topic: [PATCH v1 1/1] s390: Use string_upper() instead of open coded variant Thread-Index: AQHXuV7g4EMrXsSepEuBh6r8/SzWaKvNfv3AgAANt4CAAX8zwA== Date: Tue, 12 Oct 2021 08:04:58 +0000 Message-ID: <985bbceb3ee046bbbee6199efcf7c90c@AcuMS.aculab.com> References: <20211001130201.72545-1-andriy.shevchenko@linux.intel.com> In-Reply-To: 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 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com 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-kernel@vger.kernel.org From: Heiko Carstens > Sent: 11 October 2021 11:10 > > On Mon, Oct 11, 2021 at 08:21:15AM +0000, David Laight wrote: > > ... > > > > + * This snprintf() call does two things: > > > > + * - makes a NUL-terminated copy of the input string > > > > + * - pads it with spaces > > > > + */ > > > > + snprintf(tmp, sizeof(tmp), "%s ", name); > > > > > > I can't say I like code where I have to count spaces in order to > > > verify if the code is actually correct. > > > > What it wrong with "%-8.8s" ? > > There's nothing wrong with it, except lack of imagination on my side ;) > Andy, care to to send a separate patch just for extmem.c? Are any of the snprintf() versions actually correct at all? The implication of the comment is that the input string might not be NUL terminated - in which case it shouldn't be passed to snprintf(). I don't think you can assume that the format processing doesn't do a strlen() of any %s argument - even if a maximum field width is given. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)