[PATCH 4.9 096/111] rtc: bq4802: add error handling for devm_ioremap

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Zhouyang Jia <jiazhouyang09@xxxxxxxxx>

[ Upstream commit 7874b919866ba91bac253fa219d3d4c82bb944df ]

When devm_ioremap fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling devm_ioremap.

Signed-off-by: Zhouyang Jia <jiazhouyang09@xxxxxxxxx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/rtc/rtc-bq4802.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/rtc/rtc-bq4802.c
+++ b/drivers/rtc/rtc-bq4802.c
@@ -164,6 +164,10 @@ static int bq4802_probe(struct platform_
 	} else if (p->r->flags & IORESOURCE_MEM) {
 		p->regs = devm_ioremap(&pdev->dev, p->r->start,
 					resource_size(p->r));
+		if (!p->regs){
+			err = -ENOMEM;
+			goto out;
+		}
 		p->read = bq4802_read_mem;
 		p->write = bq4802_write_mem;
 	} else {