2020-05-02 20:34:56

by Qiushi Wu

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

From: Qiushi Wu <[email protected]>

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. To fix this problem, we
need to call mc13xxx_lock() again in this error path.

Signed-off-by: Qiushi Wu <[email protected]>
---
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

2020-05-03 12:08:39

by Markus Elfring

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

> … To fix this problem,
> we need to call mc13xxx_lock() again in this error path.

How do you think about a wording variant like the following?

Change description:
…
Thus add a call of the function “mc13xxx_lock” in an if branch
for the completion of the exception handling.


Would you like to add the tag “Fixes”?

Regards,
Markus