pinctrl: renesas: rzg2l: Fix double unlock in rzg2l_dt_subnode_to_map()

  If rzg2l_map_add_config() fails then the error handling calls
mutex_unlock(&pctrl->mutex) but we're not holding that mutex.  Move
the unlocks to before the gotos to avoid this situation.

Fixes: d3aaa7203a17 ("pinctrl: renesas: rzg2l: Add pin configuration support for pinmux groups")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
(Not tested).

 drivers/pinctrl/renesas/pinctrl-rzg2l.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
  

Hi, Dan,

Thanks for your patch!

On 10.01.2024 20:41, Dan Carpenter wrote:
> If rzg2l_map_add_config() fails then the error handling calls
> mutex_unlock(&pctrl->mutex) but we're not holding that mutex.  Move
> the unlocks to before the gotos to avoid this situation.
> 
> Fixes: d3aaa7203a17 ("pinctrl: renesas: rzg2l: Add pin configuration support for pinmux groups")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
> (Not tested).

I've tested it on RZ/G3S SoC and all is good.

However, I think, to keep the locking scheme unchanged and simpler (FMPOV),
commit d3aaa7203a17 ("pinctrl: renesas: rzg2l: Add pin configuration
support for pinmux groups") should have been call rzg2l_map_add_config()
just before the mutex is locked. That would be the following diff:

--- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
+++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
@@ -447,6 +447,16 @@ static int rzg2l_dt_subnode_to_map(struct pinctrl_dev
*pctldev,
 		name = np->name;
 	}

+	if (num_configs) {
+		ret = rzg2l_map_add_config(&maps[idx], name,
+					   PIN_MAP_TYPE_CONFIGS_GROUP,
+					   configs, num_configs);
+		if (ret < 0)
+			goto done;
+
+		idx++;
+	}
+
 	mutex_lock(&pctrl->mutex);

 	/* Register a single pin group listing all the pins we read from DT */
@@ -474,16 +484,6 @@ static int rzg2l_dt_subnode_to_map(struct pinctrl_dev
*pctldev,
 	maps[idx].data.mux.function = name;
 	idx++;

-	if (num_configs) {
-		ret = rzg2l_map_add_config(&maps[idx], name,
-					   PIN_MAP_TYPE_CONFIGS_GROUP,
-					   configs, num_configs);
-		if (ret < 0)
-			goto remove_group;
-
-		idx++;
-	}
-
 	dev_dbg(pctrl->dev, "Parsed %pOF with %d pins\n", np, num_pinmux);
 	ret = 0;
 	goto done;

Would you mind doing it like this?

Please, let me know if you want me to handle it.

Thank you,
Claudiu Beznea

> 
>  drivers/pinctrl/renesas/pinctrl-rzg2l.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pinctrl/renesas/pinctrl-rzg2l.c b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> index 80fb5011c7bb..8bbfb0530538 100644
> --- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> @@ -453,7 +453,8 @@ static int rzg2l_dt_subnode_to_map(struct pinctrl_dev *pctldev,
>  	gsel = pinctrl_generic_add_group(pctldev, name, pins, num_pinmux, NULL);
>  	if (gsel < 0) {
>  		ret = gsel;
> -		goto unlock;
> +		mutex_unlock(&pctrl->mutex);
> +		goto done;
>  	}
>  
>  	/*
> @@ -464,6 +465,7 @@ static int rzg2l_dt_subnode_to_map(struct pinctrl_dev *pctldev,
>  	fsel = pinmux_generic_add_function(pctldev, name, pin_fn, 1, psel_val);
>  	if (fsel < 0) {
>  		ret = fsel;
> +		mutex_unlock(&pctrl->mutex);
>  		goto remove_group;
>  	}
>  
> @@ -490,8 +492,6 @@ static int rzg2l_dt_subnode_to_map(struct pinctrl_dev *pctldev,
>  
>  remove_group:
>  	pinctrl_generic_remove_group(pctldev, gsel);
> -unlock:
> -	mutex_unlock(&pctrl->mutex);
>  done:
>  	*index = idx;
>  	kfree(configs);
  

On Fri, Jan 12, 2024 at 10:55:40AM +0200, claudiu beznea wrote:
> Hi, Dan,
> 
> Thanks for your patch!
> 
> On 10.01.2024 20:41, Dan Carpenter wrote:
> > If rzg2l_map_add_config() fails then the error handling calls
> > mutex_unlock(&pctrl->mutex) but we're not holding that mutex.  Move
> > the unlocks to before the gotos to avoid this situation.
> > 
> > Fixes: d3aaa7203a17 ("pinctrl: renesas: rzg2l: Add pin configuration support for pinmux groups")
> > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> > ---
> > (Not tested).
> 
> I've tested it on RZ/G3S SoC and all is good.
> 
> However, I think, to keep the locking scheme unchanged and simpler (FMPOV),
> commit d3aaa7203a17 ("pinctrl: renesas: rzg2l: Add pin configuration
> support for pinmux groups") should have been call rzg2l_map_add_config()
> just before the mutex is locked. That would be the following diff:
> 
> --- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> @@ -447,6 +447,16 @@ static int rzg2l_dt_subnode_to_map(struct pinctrl_dev
> *pctldev,
>  		name = np->name;
>  	}
> 
> +	if (num_configs) {
> +		ret = rzg2l_map_add_config(&maps[idx], name,
> +					   PIN_MAP_TYPE_CONFIGS_GROUP,
> +					   configs, num_configs);
> +		if (ret < 0)
> +			goto done;
> +
> +		idx++;
> +	}
> +
>  	mutex_lock(&pctrl->mutex);
> 
>  	/* Register a single pin group listing all the pins we read from DT */
> @@ -474,16 +484,6 @@ static int rzg2l_dt_subnode_to_map(struct pinctrl_dev
> *pctldev,
>  	maps[idx].data.mux.function = name;
>  	idx++;
        ^^^^^

> 
> -	if (num_configs) {
> -		ret = rzg2l_map_add_config(&maps[idx], name,
> -					   PIN_MAP_TYPE_CONFIGS_GROUP,
> -					   configs, num_configs);
> -		if (ret < 0)
> -			goto remove_group;
> -
> -		idx++;
> -	}

Does the ordering of the maps[] not matter?

> -
>  	dev_dbg(pctrl->dev, "Parsed %pOF with %d pins\n", np, num_pinmux);
>  	ret = 0;
>  	goto done;
> 
> Would you mind doing it like this?
> 
> Please, let me know if you want me to handle it.

Either way is fine.  Whatever is easiest.

regards,
dan carpenter
  

On 12.01.2024 11:53, Dan Carpenter wrote:
> On Fri, Jan 12, 2024 at 10:55:40AM +0200, claudiu beznea wrote:
>> Hi, Dan,
>>
>> Thanks for your patch!
>>
>> On 10.01.2024 20:41, Dan Carpenter wrote:
>>> If rzg2l_map_add_config() fails then the error handling calls
>>> mutex_unlock(&pctrl->mutex) but we're not holding that mutex.  Move
>>> the unlocks to before the gotos to avoid this situation.
>>>
>>> Fixes: d3aaa7203a17 ("pinctrl: renesas: rzg2l: Add pin configuration support for pinmux groups")
>>> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
>>> ---
>>> (Not tested).
>>
>> I've tested it on RZ/G3S SoC and all is good.
>>
>> However, I think, to keep the locking scheme unchanged and simpler (FMPOV),
>> commit d3aaa7203a17 ("pinctrl: renesas: rzg2l: Add pin configuration
>> support for pinmux groups") should have been call rzg2l_map_add_config()
>> just before the mutex is locked. That would be the following diff:
>>
>> --- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
>> +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
>> @@ -447,6 +447,16 @@ static int rzg2l_dt_subnode_to_map(struct pinctrl_dev
>> *pctldev,
>>  		name = np->name;
>>  	}
>>
>> +	if (num_configs) {
>> +		ret = rzg2l_map_add_config(&maps[idx], name,
>> +					   PIN_MAP_TYPE_CONFIGS_GROUP,
>> +					   configs, num_configs);
>> +		if (ret < 0)
>> +			goto done;
>> +
>> +		idx++;
>> +	}
>> +
>>  	mutex_lock(&pctrl->mutex);
>>
>>  	/* Register a single pin group listing all the pins we read from DT */
>> @@ -474,16 +484,6 @@ static int rzg2l_dt_subnode_to_map(struct pinctrl_dev
>> *pctldev,
>>  	maps[idx].data.mux.function = name;
>>  	idx++;
>         ^^^^^

This needs to be here for subsequent calls of rzg2l_dt_subnode_to_map() to
know which entry in maps[] to be populated next time.

> 
>>
>> -	if (num_configs) {
>> -		ret = rzg2l_map_add_config(&maps[idx], name,
>> -					   PIN_MAP_TYPE_CONFIGS_GROUP,
>> -					   configs, num_configs);
>> -		if (ret < 0)
>> -			goto remove_group;
>> -
>> -		idx++;
>> -	}
> 
> Does the ordering of the maps[] not matter?

It doesn't matter, AFAIKT. The core code checks for map type (e.g.
PIN_MAP_TYPE_CONFIGS_GROUP) when processes the data from maps[].

> 
>> -
>>  	dev_dbg(pctrl->dev, "Parsed %pOF with %d pins\n", np, num_pinmux);
>>  	ret = 0;
>>  	goto done;
>>
>> Would you mind doing it like this?
>>
>> Please, let me know if you want me to handle it.
> 
> Either way is fine.  Whatever is easiest.

Ok, I'll prepare a patch as I already tested it on my side on multiple
platforms.

Thank you,
Claudiu Beznea

> 
> regards,
> dan carpenter
>
  

On Fri, Jan 12, 2024 at 02:05:17PM +0200, claudiu beznea wrote:
> 
> Ok, I'll prepare a patch as I already tested it on my side on multiple
> platforms.

Awesome.  Thanks!

regards,
dan carpenter