[PATCH v2] rtc: mc13xxx: fix a double-unlock issue

[PATCH v2] rtc: mc13xxx: fix a double-unlock issue

[wu000273]

From: Qiushi Wu <wu000273@umn.edu>

In function mc13xxx_rtc_probe, the mc13xxx_unlock() is called
before rtc_register_device(). But in the error path of
rtc_register_device(), the mc13xxx_unlock() is called again,
which causes a double-unlock problem. Thus add a call of the
function “mc13xxx_lock” in an if branch for the completion
of the exception handling.

Fixes: e4ae7023e182a ("rtc: mc13xxx: set range")
Signed-off-by: Qiushi Wu <wu000273@umn.edu>
---
 drivers/rtc/rtc-mc13xxx.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-mc13xxx.c b/drivers/rtc/rtc-mc13xxx.c
index afce2c0b4bd6..d6802e6191cb 100644
--- a/drivers/rtc/rtc-mc13xxx.c
+++ b/drivers/rtc/rtc-mc13xxx.c
@@ -308,8 +308,10 @@ static int __init mc13xxx_rtc_probe(struct platform_device *pdev)
 	mc13xxx_unlock(mc13xxx);
 
 	ret = rtc_register_device(priv->rtc);
-	if (ret)
+	if (ret) {
+		mc13xxx_lock(mc13xxx);
 		goto err_irq_request;
+	}
 
 	return 0;
 
-- 
2.17.1

Re: [PATCH v2] rtc: mc13xxx: fix a double-unlock issue

[Alexandre Belloni]

On 03/05/2020 13:22:35-0500, wu000273@umn.edu wrote:
> From: Qiushi Wu <wu000273@umn.edu>
> 
> In function mc13xxx_rtc_probe, the mc13xxx_unlock() is called
> before rtc_register_device(). But in the error path of
> rtc_register_device(), the mc13xxx_unlock() is called again,
> which causes a double-unlock problem. Thus add a call of the
> function “mc13xxx_lock” in an if branch for the completion
> of the exception handling.
> 
> Fixes: e4ae7023e182a ("rtc: mc13xxx: set range")
> Signed-off-by: Qiushi Wu <wu000273@umn.edu>
> ---
>  drivers/rtc/rtc-mc13xxx.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
Applied, thanks.

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com