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Subject[PATCH] cris: fix locking in pcf8563.c
Date
The ioctl function was incorrectly converted to unlocked_ioctl,
this fixes the locking.

Reported-by: Michael Brumlow <mbrumlow@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
On Wednesday 09 March 2011, Michael Brumlow wrote:

> I was looking through some code and found an issue in the driver you
> wrote. The problem can be found in
> "arch/cris/arch-v10/drivers/pcf8563.c" function
> "pcf8563_unlocked_ioctl". The function locks a mutex and returns, when
> it should be locking the locking the mutex, storing the return from
> the function called and then unlocking the mutex and finally returning
> the stored value of the function called.
>
> # in its current state.
> 343 static long pcf8563_unlocked_ioctl(struct file *filp, unsigned
> int cmd, unsigned long arg)
> 344 {
> 345 int ret;
> 346
> 347 mutex_lock(&pcf8563_mutex);
> 348 return pcf8563_ioctl(filp, cmd, arg);
> 349 mutex_unlock(&pcf8563_mutex);
> 350
> 351 return ret;
> 352 }
>
> # what is suggested.
> 343 static long pcf8563_unlocked_ioctl(struct file *filp, unsigned
> int cmd, unsigned long arg)
> 344 {
> 345 int ret;
> 346
> 347 mutex_lock(&pcf8563_mutex);
> 348 ret = pcf8563_ioctl(filp, cmd, arg);
> 349 mutex_unlock(&pcf8563_mutex);
> 350
> 351 return ret;
> 352 }

You are right. This problem exists in both arch/cris/arch-v10/drivers/pcf8563.c
and arch/cris/arch-v32/drivers/pcf8563.c, and apparently both are my fault.

Arnd
---
diff --git a/arch/cris/arch-v10/drivers/pcf8563.c b/arch/cris/arch-v10/drivers/pcf8563.c
index ea69fab..1391b73 100644
--- a/arch/cris/arch-v10/drivers/pcf8563.c
+++ b/arch/cris/arch-v10/drivers/pcf8563.c
@@ -345,7 +345,7 @@ static long pcf8563_unlocked_ioctl(struct file *filp, unsigned int cmd, unsigned
int ret;

mutex_lock(&pcf8563_mutex);
- return pcf8563_ioctl(filp, cmd, arg);
+ ret = pcf8563_ioctl(filp, cmd, arg);
mutex_unlock(&pcf8563_mutex);

return ret;
diff --git a/arch/cris/arch-v32/drivers/pcf8563.c b/arch/cris/arch-v32/drivers/pcf8563.c
index b6e4fc0..208594f 100644
--- a/arch/cris/arch-v32/drivers/pcf8563.c
+++ b/arch/cris/arch-v32/drivers/pcf8563.c
@@ -341,7 +341,7 @@ static long pcf8563_unlocked_ioctl(struct file *filp, unsigned int cmd, unsigned
int ret;

mutex_lock(&pcf8563_mutex);
- return pcf8563_ioctl(filp, cmd, arg);
+ ret = pcf8563_ioctl(filp, cmd, arg);
mutex_unlock(&pcf8563_mutex);

return ret;

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