[PATCH 1/3] rtc: sa1100: fix possible race condition

[PATCH 1/3] rtc: sa1100: fix possible race condition

[Alexandre Belloni]

Both RTC IRQs are 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 IRQs 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-sa1100.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/rtc/rtc-sa1100.c b/drivers/rtc/rtc-sa1100.c
index d37893f6eaee..97c352594033 100644
--- a/drivers/rtc/rtc-sa1100.c
+++ b/drivers/rtc/rtc-sa1100.c
@@ -182,7 +182,6 @@ static const struct rtc_class_ops sa1100_rtc_ops = {
 
 int sa1100_rtc_init(struct platform_device *pdev, struct sa1100_rtc *info)
 {
-	struct rtc_device *rtc;
 	int ret;
 
 	spin_lock_init(&info->lock);
@@ -211,15 +210,14 @@ int sa1100_rtc_init(struct platform_device *pdev, struct sa1100_rtc *info)
 		writel_relaxed(0, info->rcnr);
 	}
 
-	rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &sa1100_rtc_ops,
-					THIS_MODULE);
-	if (IS_ERR(rtc)) {
+	info->rtc->ops = &sa1100_rtc_ops;
+	info->rtc->max_user_freq = RTC_FREQ;
+
+	ret = rtc_register_device(info->rtc);
+	if (ret) {
 		clk_disable_unprepare(info->clk);
-		return PTR_ERR(rtc);
+		return ret;
 	}
-	info->rtc = rtc;
-
-	rtc->max_user_freq = RTC_FREQ;
 
 	/* Fix for a nasty initialization problem the in SA11xx RTSR register.
 	 * See also the comments in sa1100_rtc_interrupt().
@@ -267,6 +265,10 @@ static int sa1100_rtc_probe(struct platform_device *pdev)
 	info->irq_1hz = irq_1hz;
 	info->irq_alarm = irq_alarm;
 
+	info->rtc = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(info->rtc))
+		return PTR_ERR(info->rtc);
+
 	ret = devm_request_irq(&pdev->dev, irq_1hz, sa1100_rtc_interrupt, 0,
 			       "rtc 1Hz", &pdev->dev);
 	if (ret) {
-- 
2.24.1

[PATCH 2/3] rtc: sa1100: set range

[Alexandre Belloni]

The SA1100 RTC is a 32bit seconds counter.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-sa1100.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/rtc/rtc-sa1100.c b/drivers/rtc/rtc-sa1100.c
index 97c352594033..82a9d4ab368f 100644
--- a/drivers/rtc/rtc-sa1100.c
+++ b/drivers/rtc/rtc-sa1100.c
@@ -212,6 +212,7 @@ int sa1100_rtc_init(struct platform_device *pdev, struct sa1100_rtc *info)
 
 	info->rtc->ops = &sa1100_rtc_ops;
 	info->rtc->max_user_freq = RTC_FREQ;
+	info->rtc->range_max = U32_MAX;
 
 	ret = rtc_register_device(info->rtc);
 	if (ret) {
-- 
2.24.1

[PATCH 3/3] rtc: sa1100: 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-sa1100.c | 21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/drivers/rtc/rtc-sa1100.c b/drivers/rtc/rtc-sa1100.c
index 82a9d4ab368f..9ccc97cf5e09 100644
--- a/drivers/rtc/rtc-sa1100.c
+++ b/drivers/rtc/rtc-sa1100.c
@@ -111,20 +111,17 @@ static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	struct sa1100_rtc *info = dev_get_drvdata(dev);
 
-	rtc_time_to_tm(readl_relaxed(info->rcnr), tm);
+	rtc_time64_to_tm(readl_relaxed(info->rcnr), tm);
 	return 0;
 }
 
 static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	struct sa1100_rtc *info = dev_get_drvdata(dev);
-	unsigned long time;
-	int ret;
 
-	ret = rtc_tm_to_time(tm, &time);
-	if (ret == 0)
-		writel_relaxed(time, info->rcnr);
-	return ret;
+	writel_relaxed(rtc_tm_to_time64(tm), info->rcnr);
+
+	return 0;
 }
 
 static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
@@ -141,24 +138,18 @@ static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct sa1100_rtc *info = dev_get_drvdata(dev);
-	unsigned long time;
-	int ret;
 
 	spin_lock_irq(&info->lock);
-	ret = rtc_tm_to_time(&alrm->time, &time);
-	if (ret != 0)
-		goto out;
 	writel_relaxed(readl_relaxed(info->rtsr) &
 		(RTSR_HZE | RTSR_ALE | RTSR_AL), info->rtsr);
-	writel_relaxed(time, info->rtar);
+	writel_relaxed(rtc_tm_to_time64(&alrm->time), info->rtar);
 	if (alrm->enabled)
 		writel_relaxed(readl_relaxed(info->rtsr) | RTSR_ALE, info->rtsr);
 	else
 		writel_relaxed(readl_relaxed(info->rtsr) & ~RTSR_ALE, info->rtsr);
-out:
 	spin_unlock_irq(&info->lock);
 
-	return ret;
+	return 0;
 }
 
 static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
-- 
2.24.1