This is a note to let you know that I've just added the patch titled
rtc: sun6i: Fix time overflow handling
to the 5.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rtc-sun6i-fix-time-overflow-handling.patch
and it can be found in the queue-5.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6e0ede398a412570d63274e03c5a0c30ead16c58
Author: Andre Przywara <andre.przywara@xxxxxxx>
Date: Fri Feb 11 12:26:28 2022 +0000
rtc: sun6i: Fix time overflow handling
[ 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 <andre.przywara@xxxxxxx>
Reviewed-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220211122643.1343315-4-andre.przywara@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index 711832c758ae..bcc0c2ce4b4e 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);
