From patchwork Fri Feb 11 12:26:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andre Przywara X-Patchwork-Id: 12743339 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 80DF6C433F5 for ; Fri, 11 Feb 2022 12:28:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=PHEAGctsH/trvaYpGdwfcsMxagZvH8C9Pzk1QEvS8Zk=; b=b7Zg8J/ZQoa3c5 B/Sk7sTW2mtF0I58+0YO4ZcdxyAMokKg2HL2at04wsE7S+2FszmSTIIz8jJK8J1SMgphS+KN/H/n0 qac5p9yQRst9mkmWBoYXhiPgjl4KW659exh2ZfgTmgh5hsJ/Ef9ObCIQoqcmUXK10amlhzXCQcUMC hKaXOdkG3DlRDwSqGO3p1GtYZyJ0GxJdGX70KUEathyCS3/nccVVnm4+nJltOs+uX/x4iGYV8B1Fs OG7hd7ptwVySY/hdF+MIob72j7LdoBn6slPQtPUDDcX3rKTRM3ho366ZUmgyGNlQCb1ZJq/ZUO+zo kmY+h4ccBd5PbxOvexVQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nIV1K-0075zT-SE; Fri, 11 Feb 2022 12:27:27 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nIV0p-0075ni-Tf for linux-arm-kernel@lists.infradead.org; Fri, 11 Feb 2022 12:26:57 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5F5E01042; Fri, 11 Feb 2022 04:26:55 -0800 (PST) Received: from donnerap.arm.com (donnerap.cambridge.arm.com [10.1.196.172]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A02483F70D; Fri, 11 Feb 2022 04:26:53 -0800 (PST) From: Andre Przywara To: Maxime Ripard , Chen-Yu Tsai , Jernej Skrabec Cc: Rob Herring , Ondrej Jirman , Icenowy Zheng , Samuel Holland , linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, Alessandro Zummo , Alexandre Belloni , linux-rtc@vger.kernel.org Subject: [PATCH v10 03/18] rtc: sun6i: Fix time overflow handling Date: Fri, 11 Feb 2022 12:26:28 +0000 Message-Id: <20220211122643.1343315-4-andre.przywara@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220211122643.1343315-1-andre.przywara@arm.com> References: <20220211122643.1343315-1-andre.przywara@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220211_042656_024789_CDD51EA4 X-CRM114-Status: GOOD ( 16.36 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 35b34d14a1db..dc3ae851841c 100644 --- a/drivers/rtc/rtc-sun6i.c +++ b/drivers/rtc/rtc-sun6i.c @@ -139,7 +139,7 @@ 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; @@ -511,10 +511,8 @@ 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) { @@ -529,9 +527,7 @@ 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; } @@ -540,7 +536,7 @@ 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);