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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 C0B86C432BE for ; Mon, 2 Aug 2021 06:30:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A4B7F60EEA for ; Mon, 2 Aug 2021 06:30:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232220AbhHBGbE (ORCPT ); Mon, 2 Aug 2021 02:31:04 -0400 Received: from smtpbg604.qq.com ([59.36.128.82]:51875 "EHLO smtpbg604.qq.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229792AbhHBGbC (ORCPT ); Mon, 2 Aug 2021 02:31:02 -0400 X-Greylist: delayed 496 seconds by postgrey-1.27 at vger.kernel.org; Mon, 02 Aug 2021 02:31:01 EDT X-QQ-mid: bizesmtp41t1627885344tq5561ka Received: from localhost.localdomain (unknown [113.89.245.207]) by esmtp6.qq.com (ESMTP) with id ; Mon, 02 Aug 2021 14:22:18 +0800 (CST) X-QQ-SSF: 01100000002000206000B00A0000000 X-QQ-FEAT: +I1LNsReFTRaBe0n8cyJfpYfsGxVjZPD3N/FdcxwlrxZwKc7m/2gsZPIGovsH XjkzYmg6tgcfos6kuz/rLPqQu/zHumGHTOeq+BU/G4OboZbFCvcMQNqoyqZ8Bb7wInD/etJ iw7pmwaY/snfXSfqOVtrhOrBeoWQ2XC8bMAEhsQ8/OpL5eO3ZROyKgtIqIoIayYtdwr8+65 ghx3SMe3z/FTTrunvHG4xUlLGaOiMylfJjtftyBBskVahc2Ver3TEDEyeU8hnjPB3T0P+03 8tzJCi79USCGw1pjOn7JPWMhc60dgiPhdh6O7zcEwdvjxXQUcXCbzbea980DiYc1oSFHlgg n/oPRQehSASnB8yK94= X-QQ-GoodBg: 0 From: Icenowy Zheng To: Rob Herring , Maxime Ripard , Chen-Yu Tsai , Jernej Skrabec , Ulf Hansson , Linus Walleij , Alexandre Belloni , Andre Przywara , Samuel Holland Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 01/17] rtc: sun6i: Fix time overflow handling Date: Mon, 2 Aug 2021 14:21:56 +0800 Message-Id: <20210802062212.73220-2-icenowy@sipeed.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210802062212.73220-1-icenowy@sipeed.com> References: <20210802062212.73220-1-icenowy@sipeed.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-QQ-SENDSIZE: 520 Feedback-ID: bizesmtp:sipeed.com:qybgspam:qybgspam4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andre Przywara 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 --- 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 adec1b14a8de..c551ebf0ac00 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); -- 2.30.2