build/patch/kernel/archive/sunxi-5.15/patches.armbian/drv-rtc-sun6i-Fix-time-overflow-handling.patch

74 lines
2.4 KiB
Diff

From 8ac06a34de49b9dab7889d9e0693466d3cca10e7 Mon Sep 17 00:00:00 2001
From: Andre Przywara <andre.przywara@arm.com>
Date: Fri, 18 Jun 2021 14:37:56 +0100
Subject: [PATCH 010/101] drv:rtc:sun6i: Fix time overflow handling
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 50de48cf6..f1328ddbf 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -142,7 +142,7 @@ 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;
@@ -514,10 +514,8 @@ 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) {
@@ -532,9 +530,7 @@ 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;
}
@@ -543,7 +539,7 @@ 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);
--
2.31.1