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 DA8A9C282C2 for ; Thu, 7 Feb 2019 20:53:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD14C2084D for ; Thu, 7 Feb 2019 20:53:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727638AbfBGUxx (ORCPT ); Thu, 7 Feb 2019 15:53:53 -0500 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:49059 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727501AbfBGUxx (ORCPT ); Thu, 7 Feb 2019 15:53:53 -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 relay1-d.mail.gandi.net (Postfix) with ESMTPSA id A05DB240009; Thu, 7 Feb 2019 20:53:50 +0000 (UTC) Date: Thu, 7 Feb 2019 21:53:50 +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: pm8xxx: fix unintended sign extension Message-ID: <20190207205350.GM4719@piout.net> References: <20190206103102.19345-1-colin.king@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190206103102.19345-1-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 10:31:02+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#1309693 ("Unintended sign extension") > > Fixes: 9a9a54ad7aa2 ("drivers/rtc: add support for Qualcomm PMIC8xxx RTC") > Signed-off-by: Colin Ian King > --- > drivers/rtc/rtc-pm8xxx.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > Applied, thanks. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com