[PATCH 1/3] rtc: ds1374: fix possible race condition

[PATCH 1/3] rtc: ds1374: fix possible race condition

[Alexandre Belloni]

The RTC IRQ is requested before the struct rtc_device is allocated,
this may lead to a NULL pointer dereference in the IRQ handler.

To fix this issue, allocating the rtc_device struct before requesting
the RTC IRQ using devm_rtc_allocate_device, and use rtc_register_device
to register the RTC device.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-ds1374.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/rtc/rtc-ds1374.c b/drivers/rtc/rtc-ds1374.c
index 6e9ddcd03992..cb18a11a3c76 100644
--- a/drivers/rtc/rtc-ds1374.c
+++ b/drivers/rtc/rtc-ds1374.c
@@ -620,6 +620,10 @@ static int ds1374_probe(struct i2c_client *client,
 	if (!ds1374)
 		return -ENOMEM;
 
+	ds1374->rtc = devm_rtc_allocate_device(&client->dev);
+	if (IS_ERR(ds1374->rtc))
+		return PTR_ERR(ds1374->rtc);
+
 	ds1374->client = client;
 	i2c_set_clientdata(client, ds1374);
 
@@ -641,12 +645,11 @@ static int ds1374_probe(struct i2c_client *client,
 		device_set_wakeup_capable(&client->dev, 1);
 	}
 
-	ds1374->rtc = devm_rtc_device_register(&client->dev, client->name,
-						&ds1374_rtc_ops, THIS_MODULE);
-	if (IS_ERR(ds1374->rtc)) {
-		dev_err(&client->dev, "unable to register the class device\n");
-		return PTR_ERR(ds1374->rtc);
-	}
+	ds1374->rtc->ops = &ds1374_rtc_ops;
+
+	ret = rtc_register_device(ds1374->rtc);
+	if (ret)
+		return ret;
 
 #ifdef CONFIG_RTC_DRV_DS1374_WDT
 	save_client = client;
-- 
2.24.1

[PATCH 2/3] rtc: ds1374: set range

[Alexandre Belloni]

The ds1374 is a 32bit seconds counter.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-ds1374.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/rtc/rtc-ds1374.c b/drivers/rtc/rtc-ds1374.c
index cb18a11a3c76..843fcbf5e940 100644
--- a/drivers/rtc/rtc-ds1374.c
+++ b/drivers/rtc/rtc-ds1374.c
@@ -646,6 +646,7 @@ static int ds1374_probe(struct i2c_client *client,
 	}
 
 	ds1374->rtc->ops = &ds1374_rtc_ops;
+	ds1374->rtc->range_max = U32_MAX;
 
 	ret = rtc_register_device(ds1374->rtc);
 	if (ret)
-- 
2.24.1

[PATCH 3/3] rtc: ds1374: switch to rtc_time64_to_tm/rtc_tm_to_time64

[Alexandre Belloni]

Call the 64bit versions of rtc_tm time conversion.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-ds1374.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/rtc/rtc-ds1374.c b/drivers/rtc/rtc-ds1374.c
index 843fcbf5e940..9c51a12cf70f 100644
--- a/drivers/rtc/rtc-ds1374.c
+++ b/drivers/rtc/rtc-ds1374.c
@@ -164,7 +164,7 @@ static int ds1374_read_time(struct device *dev, struct rtc_time *time)
 
 	ret = ds1374_read_rtc(client, &itime, DS1374_REG_TOD0, 4);
 	if (!ret)
-		rtc_time_to_tm(itime, time);
+		rtc_time64_to_tm(itime, time);
 
 	return ret;
 }
@@ -172,9 +172,8 @@ static int ds1374_read_time(struct device *dev, struct rtc_time *time)
 static int ds1374_set_time(struct device *dev, struct rtc_time *time)
 {
 	struct i2c_client *client = to_i2c_client(dev);
-	unsigned long itime;
+	unsigned long itime = rtc_tm_to_time64(time);
 
-	rtc_tm_to_time(time, &itime);
 	return ds1374_write_rtc(client, itime, DS1374_REG_TOD0, 4);
 }
 
@@ -212,7 +211,7 @@ static int ds1374_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 	if (ret)
 		goto out;
 
-	rtc_time_to_tm(now + cur_alarm, &alarm->time);
+	rtc_time64_to_tm(now + cur_alarm, &alarm->time);
 	alarm->enabled = !!(cr & DS1374_REG_CR_WACE);
 	alarm->pending = !!(sr & DS1374_REG_SR_AF);
 
@@ -237,8 +236,8 @@ static int ds1374_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 	if (ret < 0)
 		return ret;
 
-	rtc_tm_to_time(&alarm->time, &new_alarm);
-	rtc_tm_to_time(&now, &itime);
+	new_alarm = rtc_tm_to_time64(&alarm->time);
+	itime = rtc_tm_to_time64(&now);
 
 	/* This can happen due to races, in addition to dates that are
 	 * truly in the past.  To avoid requiring the caller to check for
-- 
2.24.1