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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 75D97C282C4 for ; Thu, 7 Feb 2019 20:53:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 483792146E for ; Thu, 7 Feb 2019 20:53:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727476AbfBGUxi (ORCPT ); Thu, 7 Feb 2019 15:53:38 -0500 Received: from relay3-d.mail.gandi.net ([217.70.183.195]:40159 "EHLO relay3-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727035AbfBGUxi (ORCPT ); Thu, 7 Feb 2019 15:53:38 -0500 X-Originating-IP: 86.202.231.219 Received: from localhost (lfbn-lyo-1-149-219.w86-202.abo.wanadoo.fr [86.202.231.219]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay3-d.mail.gandi.net (Postfix) with ESMTPSA id 7310D60003; Thu, 7 Feb 2019 20:53:36 +0000 (UTC) Date: Thu, 7 Feb 2019 21:53:36 +0100 From: Alexandre Belloni To: Colin King Cc: Alessandro Zummo , linux-rtc@vger.kernel.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] rtc: 88pm80x: fix unintended sign extension Message-ID: <20190207205336.GL4719@piout.net> References: <20190206100811.13315-1-colin.king@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190206100811.13315-1-colin.king@canonical.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org On 06/02/2019 10:08:11+0000, Colin King wrote: > From: Colin Ian King > > Shifting a u8 by 24 will cause the value to be promoted to an integer. If > the top bit of the u8 is set then the following conversion to an unsigned > long will sign extend the value causing the upper 32 bits to be set in > the result. > > Fix this by casting the u8 value to an unsigned long before the shift. > > Detected by CoverityScan, CID#714646-714649 ("Unintended sign extension") > > Fixes: 2985c29c1964 ("rtc: Add rtc support to 88PM80X PMIC") > Signed-off-by: Colin Ian King > --- > drivers/rtc/rtc-88pm80x.c | 21 ++++++++++++++------- > 1 file changed, 14 insertions(+), 7 deletions(-) > Applied, thanks. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com