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=-15.5 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham 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 51FF8C433ED for ; Sat, 8 May 2021 16:12:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2EF7B61261 for ; Sat, 8 May 2021 16:12:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229591AbhEHQNE (ORCPT ); Sat, 8 May 2021 12:13:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:58360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229500AbhEHQNE (ORCPT ); Sat, 8 May 2021 12:13:04 -0400 Received: from jic23-huawei (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DEFEB61260; Sat, 8 May 2021 16:11:59 +0000 (UTC) Date: Sat, 8 May 2021 17:12:58 +0100 From: Jonathan Cameron To: Colin King Cc: Lars-Peter Clausen , Nathan Chancellor , Nick Desaulniers , Jon Brenner , linux-iio@vger.kernel.org, clang-built-linux@googlegroups.com, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] iio: tsl2583: Fix division by a zero lux_val Message-ID: <20210508171258.2ef71a70@jic23-huawei> In-Reply-To: <20210507183041.115864-1-colin.king@canonical.com> References: <20210507183041.115864-1-colin.king@canonical.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kernel-janitors@vger.kernel.org On Fri, 7 May 2021 19:30:41 +0100 Colin King wrote: > From: Colin Ian King > > The lux_val returned from tsl2583_get_lux can potentially be zero, > so check for this to avoid a division by zero and an overflowed > gain_trim_val. > > Fixes clang scan-build warning: > > drivers/iio/light/tsl2583.c:345:40: warning: Either the > condition 'lux_val<0' is redundant or there is division > by zero at line 345. [zerodivcond] > > Fixes: ac4f6eee8fe8 ("staging: iio: TAOS tsl258x: Device driver") > Signed-off-by: Colin Ian King Definitely looks like it could happen so applied to the fixes-togreg branch of iio.git and marked for stable. Thanks, Jonathan > --- > drivers/iio/light/tsl2583.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/iio/light/tsl2583.c b/drivers/iio/light/tsl2583.c > index 0f787bfc88fc..c9d8f07a6fcd 100644 > --- a/drivers/iio/light/tsl2583.c > +++ b/drivers/iio/light/tsl2583.c > @@ -341,6 +341,14 @@ static int tsl2583_als_calibrate(struct iio_dev *indio_dev) > return lux_val; > } > > + /* Avoid division by zero of lux_value later on */ > + if (lux_val == 0) { > + dev_err(&chip->client->dev, > + "%s: lux_val of 0 will produce out of range trim_value\n", > + __func__); > + return -ENODATA; > + } > + > gain_trim_val = (unsigned int)(((chip->als_settings.als_cal_target) > * chip->als_settings.als_gain_trim) / lux_val); > if ((gain_trim_val < 250) || (gain_trim_val > 4000)) {