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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14A35C433F5 for ; Thu, 7 Apr 2022 01:23:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238557AbiDGBZv (ORCPT ); Wed, 6 Apr 2022 21:25:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239516AbiDGBTT (ORCPT ); Wed, 6 Apr 2022 21:19:19 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D8DF1A8FF0; Wed, 6 Apr 2022 18:14:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 41A8561DB0; Thu, 7 Apr 2022 01:14:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A916C385A3; Thu, 7 Apr 2022 01:14:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649294076; bh=rmjlrZ3jRBAG1u+k/uE6IQjsP8+3rNHHrRvB1TBMCIc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S9ftank2rUUH02RET8lUiYj5EiyHfsflHDl8bcdO9Iv1N/dTSkE8CT/JP5BwVsOhd 8r+hZ7t9FbpvszynBkNJrPfzCTmB6lw9ZFTmdEbpguI29ARB1O3+t/yjlHCUWq16sG s2jDxHWvXmc9wB+yrBVNyEBoQxrhatt7IHOh4hRi9FoGO0JhHJPYFKktdyA+Rjery3 HSxKos3jCRz9U1BRiS9H+SzrgmKKpdFk38zkF5EqkQbMSYaJ4ClwqiNDb+TbOpqqrE Of6DWPd0TUVNaeiBfvBQSJsYxEyJ+SAXRGAlooVG9uA3RJvwMmcOI0r/QCucN1iNXb 8dfiEI+NTFNBQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Andre Przywara , Jernej Skrabec , Alexandre Belloni , Sasha Levin , a.zummo@towertech.it, wens@csie.org, samuel@sholland.org, linux-rtc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev Subject: [PATCH AUTOSEL 5.10 10/25] rtc: sun6i: Fix time overflow handling Date: Wed, 6 Apr 2022 21:13:58 -0400 Message-Id: <20220407011413.114662-10-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220407011413.114662-1-sashal@kernel.org> References: <20220407011413.114662-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andre Przywara [ Upstream commit 9f6cd82eca7e91a0d0311242a87c6aa3c2737968 ] Using "unsigned long" for UNIX timestamps is never a good idea, and comparing the value of such a variable against U32_MAX does not do anything useful on 32-bit systems. Use the proper time64_t type when dealing with timestamps, and avoid cutting down the time range unnecessarily. This also fixes the flawed check for the alarm time being too far into the future. The check for this condition is actually somewhat theoretical, as the RTC counts till 2033 only anyways, and 2^32 seconds from now is not before the year 2157 - at which point I hope nobody will be using this hardware anymore. Signed-off-by: Andre Przywara Reviewed-by: Jernej Skrabec Signed-off-by: Alexandre Belloni Link: https://lore.kernel.org/r/20220211122643.1343315-4-andre.przywara@arm.com Signed-off-by: Sasha Levin --- drivers/rtc/rtc-sun6i.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c index f2818cdd11d8..52b36b7c6129 100644 --- a/drivers/rtc/rtc-sun6i.c +++ b/drivers/rtc/rtc-sun6i.c @@ -138,7 +138,7 @@ struct sun6i_rtc_dev { const struct sun6i_rtc_clk_data *data; void __iomem *base; int irq; - unsigned long alarm; + time64_t alarm; struct clk_hw hw; struct clk_hw *int_osc; @@ -510,10 +510,8 @@ static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm) struct sun6i_rtc_dev *chip = dev_get_drvdata(dev); struct rtc_time *alrm_tm = &wkalrm->time; struct rtc_time tm_now; - unsigned long time_now = 0; - unsigned long time_set = 0; - unsigned long time_gap = 0; - int ret = 0; + time64_t time_now, time_set; + int ret; ret = sun6i_rtc_gettime(dev, &tm_now); if (ret < 0) { @@ -528,9 +526,7 @@ static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm) return -EINVAL; } - time_gap = time_set - time_now; - - if (time_gap > U32_MAX) { + if ((time_set - time_now) > U32_MAX) { dev_err(dev, "Date too far in the future\n"); return -EINVAL; } @@ -539,7 +535,7 @@ static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm) writel(0, chip->base + SUN6I_ALRM_COUNTER); usleep_range(100, 300); - writel(time_gap, chip->base + SUN6I_ALRM_COUNTER); + writel(time_set - time_now, chip->base + SUN6I_ALRM_COUNTER); chip->alarm = time_set; sun6i_rtc_setaie(wkalrm->enabled, chip); -- 2.35.1