From: Icenowy Zheng <icenowy@sipeed.com> To: Rob Herring <robh+dt@kernel.org>, Maxime Ripard <mripard@kernel.org>, Chen-Yu Tsai <wens@csie.org>, Jernej Skrabec <jernej.skrabec@gmail.com>, Ulf Hansson <ulf.hansson@linaro.org>, Linus Walleij <linus.walleij@linaro.org>, Alexandre Belloni <alexandre.belloni@bootlin.com>, Andre Przywara <andre.przywara@arm.com>, Samuel Holland <samuel@sholland.org> 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 [thread overview] Message-ID: <20210802062212.73220-2-icenowy@sipeed.com> (raw) In-Reply-To: <20210802062212.73220-1-icenowy@sipeed.com> From: Andre Przywara <andre.przywara@arm.com> 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 <andre.przywara@arm.com> Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com> --- 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
WARNING: multiple messages have this Message-ID (diff)
From: Icenowy Zheng <icenowy@sipeed.com> To: Rob Herring <robh+dt@kernel.org>, Maxime Ripard <mripard@kernel.org>, Chen-Yu Tsai <wens@csie.org>, Jernej Skrabec <jernej.skrabec@gmail.com>, Ulf Hansson <ulf.hansson@linaro.org>, Linus Walleij <linus.walleij@linaro.org>, Alexandre Belloni <alexandre.belloni@bootlin.com>, Andre Przywara <andre.przywara@arm.com>, Samuel Holland <samuel@sholland.org> 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 [thread overview] Message-ID: <20210802062212.73220-2-icenowy@sipeed.com> (raw) In-Reply-To: <20210802062212.73220-1-icenowy@sipeed.com> From: Andre Przywara <andre.przywara@arm.com> 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 <andre.przywara@arm.com> Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com> --- 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-08-02 6:24 UTC|newest] Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-02 6:21 [PATCH 00/17] Basical Allwinner R329 support Icenowy Zheng 2021-08-02 6:21 ` Icenowy Zheng 2021-08-02 6:21 ` Icenowy Zheng [this message] 2021-08-02 6:21 ` [PATCH 01/17] rtc: sun6i: Fix time overflow handling Icenowy Zheng 2021-08-02 6:21 ` [PATCH 02/17] rtc: sun6i: Add support for linear day storage Icenowy Zheng 2021-08-02 6:21 ` Icenowy Zheng 2021-08-02 6:21 ` [PATCH 03/17] rtc: sun6i: Add support for broken-down alarm registers Icenowy Zheng 2021-08-02 6:21 ` Icenowy Zheng 2021-08-02 6:21 ` [PATCH 04/17] dt-bindings: rtc: sun6i: add compatible string for R329 RTC Icenowy Zheng 2021-08-02 6:21 ` Icenowy Zheng 2021-08-06 21:39 ` Rob Herring 2021-08-06 21:39 ` Rob Herring 2021-08-02 6:22 ` [PATCH 05/17] rtc: sun6i: add support " Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-02 6:22 ` [PATCH 06/17] dt-bindings: pinctrl: document Allwinner R329 PIO and R-PIO Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-06 21:40 ` Rob Herring 2021-08-06 21:40 ` Rob Herring 2021-08-18 8:48 ` Maxime Ripard 2021-08-18 8:48 ` Maxime Ripard 2021-08-19 2:40 ` Samuel Holland 2021-08-19 2:40 ` Samuel Holland 2021-08-02 6:22 ` [PATCH 07/17] pinctrl: sunxi: add support for R329 CPUX pin controller Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-11 9:23 ` Linus Walleij 2021-08-11 9:23 ` Linus Walleij 2021-08-11 9:23 ` Linus Walleij 2021-08-18 8:48 ` Maxime Ripard 2021-08-18 8:48 ` Maxime Ripard 2021-08-19 3:09 ` Samuel Holland 2021-08-19 3:09 ` Samuel Holland 2021-08-02 6:22 ` [PATCH 08/17] pinctrl: sunxi: add support for R329 R-PIO " Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-18 8:52 ` Maxime Ripard 2021-08-18 8:52 ` Maxime Ripard 2021-08-19 3:22 ` Samuel Holland 2021-08-19 3:22 ` Samuel Holland 2021-08-02 6:22 ` [PATCH 09/17] dt-bindings: clock: sunxi-ng: add compatibles for R329 CCUs Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-06 21:41 ` Rob Herring 2021-08-06 21:41 ` Rob Herring 2021-08-02 6:22 ` [PATCH 10/17] clk: sunxi=ng: add support for R329 R-CCU Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-02 9:03 ` Icenowy Zheng 2021-08-02 9:03 ` Icenowy Zheng 2021-08-02 9:52 ` Icenowy Zheng 2021-08-02 9:52 ` Icenowy Zheng 2021-08-06 21:42 ` Rob Herring 2021-08-06 21:42 ` Rob Herring 2021-08-18 8:50 ` Maxime Ripard 2021-08-18 8:50 ` Maxime Ripard 2021-08-20 0:55 ` Samuel Holland 2021-08-20 0:55 ` Samuel Holland 2021-08-20 4:34 ` Jernej Škrabec 2021-08-20 4:34 ` Jernej Škrabec 2021-08-25 14:50 ` Maxime Ripard 2021-08-25 14:50 ` Maxime Ripard 2021-08-25 15:03 ` Jernej Škrabec 2021-08-25 15:03 ` Jernej Škrabec 2021-08-25 15:37 ` Maxime Ripard 2021-08-25 15:37 ` Maxime Ripard 2021-08-26 0:20 ` Samuel Holland 2021-08-26 0:20 ` Samuel Holland 2021-08-02 6:22 ` [PATCH 11/17] clk: sunxi-ng: add support for Allwinner R329 CCU Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-06 21:42 ` Rob Herring 2021-08-06 21:42 ` Rob Herring 2021-08-20 2:41 ` Samuel Holland 2021-08-20 2:41 ` Samuel Holland 2021-08-20 3:52 ` Icenowy Zheng 2021-08-20 3:52 ` Icenowy Zheng 2021-08-25 14:54 ` Maxime Ripard 2021-08-25 14:54 ` Maxime Ripard 2021-08-02 6:22 ` [PATCH 12/17] dt-bindings: mmc: sunxi-mmc: add R329 MMC compatible string Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-06 21:42 ` Rob Herring 2021-08-06 21:42 ` Rob Herring 2021-08-18 8:47 ` Maxime Ripard 2021-08-18 8:47 ` Maxime Ripard 2021-08-02 6:22 ` [PATCH 13/17] mmc: sunxi: add support for R329 MMC controllers Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-18 8:47 ` Maxime Ripard 2021-08-18 8:47 ` Maxime Ripard 2021-08-20 2:43 ` Samuel Holland 2021-08-20 2:43 ` Samuel Holland 2021-08-02 6:22 ` [PATCH 14/17] dt-bindings: arm: sunxi: add compatible strings for Sipeed MaixSense Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-06 21:43 ` Rob Herring 2021-08-06 21:43 ` Rob Herring 2021-08-18 9:03 ` Maxime Ripard 2021-08-18 9:03 ` Maxime Ripard 2021-08-02 6:22 ` [PATCH 15/17] arm64: allwinner: dts: add DTSI file for R329 SoC Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-18 9:01 ` Maxime Ripard 2021-08-18 9:01 ` Maxime Ripard 2021-08-18 9:15 ` Icenowy Zheng 2021-08-18 9:15 ` Icenowy Zheng 2021-08-19 2:32 ` Samuel Holland 2021-08-19 2:32 ` Samuel Holland 2021-08-20 3:06 ` Samuel Holland 2021-08-20 3:06 ` Samuel Holland 2021-08-25 15:00 ` Maxime Ripard 2021-08-25 15:00 ` Maxime Ripard 2021-08-20 2:59 ` Samuel Holland 2021-08-20 2:59 ` Samuel Holland 2021-08-02 6:22 ` [PATCH 16/17] arm64: allwinner: dts: r329: add DTSI file for Sipeed Maix IIA Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-02 6:22 ` [PATCH 17/17] arm64: allwinner: dts: r329: add support for Sipeed MaixSense Icenowy Zheng 2021-08-02 6:22 ` Icenowy Zheng 2021-08-10 11:04 ` [PATCH 00/17] Basical Allwinner R329 support Ulf Hansson 2021-08-10 11:04 ` Ulf Hansson 2021-08-10 11:04 ` Ulf Hansson
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