Received: by 10.223.185.116 with SMTP id b49csp4089182wrg; Tue, 13 Feb 2018 12:33:38 -0800 (PST) X-Google-Smtp-Source: AH8x225ycbm4nFzq8Aozq7bDmcoY3pjsan4WMybzKO+yLOTMZuM1KGyAxajyItdPHXpJulyEfwZh X-Received: by 10.99.154.73 with SMTP id e9mr1898018pgo.26.1518554018608; Tue, 13 Feb 2018 12:33:38 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1518554018; cv=none; d=google.com; s=arc-20160816; b=jL5lu4yArOcs9o3JsguRl4Tb/BDs2aI+s3nA6/tMx3HZ8U+U6cJ26pubVpiAFDd7gY SpVWE/atkKDaTyrDN7+udpbXqSKlKKgEn1l1v+IRSRGoQ3SuNkpkE+kFHrR1ES50BH7K yYbYaaBYYpApWe6kZRVO/wWdOrDryjGuCtjSQCqtgBHZOp7UmRwLyydVl08YFCVzdphZ 3FKRBaKciTp97AZoWII4pNmznzbsIogGnSZsuZTHSQSZTt6W2Wh7FlwwEkWUvkslFdjR Iw6aVLkFSXCa4se3YXNL5O9OG8NY0D/pmV3tlRnPRUb1Lqgyj04aOuVFwQWDWjm8k8E/ HhjQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:arc-authentication-results; bh=YDUmBW2/C8WkgFUTdhv4EuM3q4wuott4Ee0oaVlyGeU=; b=rDaqNTljw/Hpy0RkMvpGQLth0Ao2cPhjP6m/4JpquxjVIZMfZUUkQpF35cqrAwzHwQ ncmyYWGrhTjI9CUdSj5UtOhWKUAcLIz980ELMD6dQWhx6jtNUZjSSuDodDizzXlFmJNF O0FeTbgqTqnEre8mZK7bevTOcVcrecjgXQOFrTWTsEp9VwZAgyFtxxI/ujB0CLWe7lMs hHWeB03ULHZxiB1pWLD1YsW+DAOMQT+/+c9SmDXoDUiHdvDfdyncX5wXUiUvIf2Ijs7d BXGHEkQit625x9T9App+9RWxA62ZKErIawOjYLyvQuy46EwrXc5+0pCTQHhBzpxoMGRO wuGQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id l91-v6si179895plb.345.2018.02.13.12.33.23; Tue, 13 Feb 2018 12:33:38 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965761AbeBMUc3 (ORCPT + 99 others); Tue, 13 Feb 2018 15:32:29 -0500 Received: from mail.free-electrons.com ([62.4.15.54]:36909 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965611AbeBMUc2 (ORCPT ); Tue, 13 Feb 2018 15:32:28 -0500 Received: by mail.free-electrons.com (Postfix, from userid 110) id 9CABE207FE; Tue, 13 Feb 2018 21:32:26 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on mail.free-electrons.com X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,SHORTCIRCUIT, URIBL_BLOCKED shortcircuit=ham autolearn=disabled version=3.4.0 Received: from localhost (unknown [88.191.26.124]) by mail.free-electrons.com (Postfix) with ESMTPSA id 65283203A0; Tue, 13 Feb 2018 21:32:16 +0100 (CET) Date: Tue, 13 Feb 2018 21:32:16 +0100 From: Alexandre Belloni To: Baolin Wang Cc: a.zummo@towertech.it, arnd@arndb.de, broonie@kernel.org, linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RESEND PATCH] rtc: Fix overflow when converting time64_t to rtc_time Message-ID: <20180213203216.GC30929@piout.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.3 (2018-01-21) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 26/01/2018 at 13:06:01 +0800, Baolin Wang wrote: > If we convert one large time values to rtc_time, in the original formula > 'days * 86400' can be overflowed in 'unsigned int' type to make the formula > get one incorrect remain seconds value. Thus we can use div_s64_rem() > function to avoid this situation. > > Signed-off-by: Baolin Wang > --- > drivers/rtc/rtc-lib.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > Applied, thanks. -- Alexandre Belloni, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering http://bootlin.com