[PATCH] firmware: stratix10-svc: Fix some error handling paths in 'stratix10_svc_drv_probe()'

[PATCH] firmware: stratix10-svc: Fix some error handling paths in 'stratix10_svc_drv_probe()'

[Christophe JAILLET]

If an error occurs after calling 'kfifo_alloc()', the allocated memory
should be freed with 'kfifo_free()', as already done in the remove
function.

Fixes: b5dc75c915cd ("firmware: stratix10-svc: extend svc to support new RSU features")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/firmware/stratix10-svc.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-svc.c
index d5f0769f3761..cc9df9589195 100644
--- a/drivers/firmware/stratix10-svc.c
+++ b/drivers/firmware/stratix10-svc.c
@@ -1043,24 +1043,31 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
 
 	/* add svc client device(s) */
 	svc = devm_kzalloc(dev, sizeof(*svc), GFP_KERNEL);
-	if (!svc)
-		return -ENOMEM;
+	if (!svc) {
+		ret = -ENOMEM;
+		goto err_free_kfifo;
+	}
 
 	svc->stratix10_svc_rsu = platform_device_alloc(STRATIX10_RSU, 0);
 	if (!svc->stratix10_svc_rsu) {
 		dev_err(dev, "failed to allocate %s device\n", STRATIX10_RSU);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto err_free_kfifo;
 	}
 
 	ret = platform_device_add(svc->stratix10_svc_rsu);
 	if (ret) {
 		platform_device_put(svc->stratix10_svc_rsu);
-		return ret;
+		goto err_free_kfifo;
 	}
 	dev_set_drvdata(dev, svc);
 
 	pr_info("Intel Service Layer Driver Initialized\n");
 
+	return 0;
+
+err_free_kfifo:
+	kfifo_free(&controller->svc_fifo);
 	return ret;
 }
 
-- 
2.25.1

Re: [PATCH] firmware: stratix10-svc: Fix some error handling paths in 'stratix10_svc_drv_probe()'

[Markus Elfring]

> If an error occurs after calling 'kfifo_alloc()', the allocated memory
> should be freed with 'kfifo_free()', as already done in the remove
> function.

I suggest to reconsider software development consequences around
another implementation detail for such exception handling.


…
> +++ b/drivers/firmware/stratix10-svc.c
> @@ -1043,24 +1043,31 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
…
>  	svc = devm_kzalloc(dev, sizeof(*svc), GFP_KERNEL);
…
> +	if (!svc) {
> +		ret = -ENOMEM;
> +		goto err_free_kfifo;
> +	}

Would you like to take the possibility into account to avoid
the duplicate specification of this error code assignment
by adding another jump target?

-		return -ENOMEM;
+		goto e_nomem;


>+	return 0;
>+

+e_nomem:
+	ret = -ENOMEM;

>+err_free_kfifo:
>+	kfifo_free(&controller->svc_fifo);
> 	return ret;
>  }


By the way:
How do you think about to omit the error message “failed to allocate FIFO”
for a failed call of the function “kfifo_alloc”?

Regards,
Markus

Re: [PATCH] firmware: stratix10-svc: Fix some error handling paths in 'stratix10_svc_drv_probe()'

[Dan Carpenter]

On Sun, Apr 26, 2020 at 09:03:07PM +0200, Christophe JAILLET wrote:
> If an error occurs after calling 'kfifo_alloc()', the allocated memory
> should be freed with 'kfifo_free()', as already done in the remove
> function.
> 
> Fixes: b5dc75c915cd ("firmware: stratix10-svc: extend svc to support new RSU features")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
>  drivers/firmware/stratix10-svc.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-svc.c
> index d5f0769f3761..cc9df9589195 100644
> --- a/drivers/firmware/stratix10-svc.c
> +++ b/drivers/firmware/stratix10-svc.c
> @@ -1043,24 +1043,31 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
>  
>  	/* add svc client device(s) */
>  	svc = devm_kzalloc(dev, sizeof(*svc), GFP_KERNEL);
> -	if (!svc)
> -		return -ENOMEM;
> +	if (!svc) {
> +		ret = -ENOMEM;
> +		goto err_free_kfifo;
> +	}
>  
>  	svc->stratix10_svc_rsu = platform_device_alloc(STRATIX10_RSU, 0);
>  	if (!svc->stratix10_svc_rsu) {
>  		dev_err(dev, "failed to allocate %s device\n", STRATIX10_RSU);
> -		return -ENOMEM;
> +		ret = -ENOMEM;
> +		goto err_free_kfifo;
>  	}
>  
>  	ret = platform_device_add(svc->stratix10_svc_rsu);
>  	if (ret) {
>  		platform_device_put(svc->stratix10_svc_rsu);

Why not move this to the unwind code as well and do "goto put_platform;"?

regards,
dan carpenter

> -		return ret;
> +		goto err_free_kfifo;
>  	}
>  	dev_set_drvdata(dev, svc);
>  
>  	pr_info("Intel Service Layer Driver Initialized\n");
>  
> +	return 0;
> +
> +err_free_kfifo:
> +	kfifo_free(&controller->svc_fifo);
>  	return ret;
>  }

Re: [PATCH] firmware: stratix10-svc: Fix some error handling paths in 'stratix10_svc_drv_probe()'

[Christophe JAILLET]

Le 28/04/2020 à 13:55, Dan Carpenter a écrit :
> On Sun, Apr 26, 2020 at 09:03:07PM +0200, Christophe JAILLET wrote:
>> If an error occurs after calling 'kfifo_alloc()', the allocated memory
>> should be freed with 'kfifo_free()', as already done in the remove
>> function.
>>
>> Fixes: b5dc75c915cd ("firmware: stratix10-svc: extend svc to support new RSU features")
>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>> ---
>>   drivers/firmware/stratix10-svc.c | 15 +++++++++++----
>>   1 file changed, 11 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-svc.c
>> index d5f0769f3761..cc9df9589195 100644
>> --- a/drivers/firmware/stratix10-svc.c
>> +++ b/drivers/firmware/stratix10-svc.c
>> @@ -1043,24 +1043,31 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev)
>>   
>>   	/* add svc client device(s) */
>>   	svc = devm_kzalloc(dev, sizeof(*svc), GFP_KERNEL);
>> -	if (!svc)
>> -		return -ENOMEM;
>> +	if (!svc) {
>> +		ret = -ENOMEM;
>> +		goto err_free_kfifo;
>> +	}
>>   
>>   	svc->stratix10_svc_rsu = platform_device_alloc(STRATIX10_RSU, 0);
>>   	if (!svc->stratix10_svc_rsu) {
>>   		dev_err(dev, "failed to allocate %s device\n", STRATIX10_RSU);
>> -		return -ENOMEM;
>> +		ret = -ENOMEM;
>> +		goto err_free_kfifo;
>>   	}
>>   
>>   	ret = platform_device_add(svc->stratix10_svc_rsu);
>>   	if (ret) {
>>   		platform_device_put(svc->stratix10_svc_rsu);
> Why not move this to the unwind code as well and do "goto put_platform;"?

Sure, I'll send a V2.

CJ


> regards,
> dan carpenter
>
>> -		return ret;
>> +		goto err_free_kfifo;
>>   	}
>>   	dev_set_drvdata(dev, svc);
>>   
>>   	pr_info("Intel Service Layer Driver Initialized\n");
>>   
>> +	return 0;
>> +
>> +err_free_kfifo:
>> +	kfifo_free(&controller->svc_fifo);
>>   	return ret;
>>   }
>