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* [V1] mtd: devices: docg3:- Handle return value of devm_ioremap.
@ 2016-12-11 18:01 Arvind Yadav
  2016-12-11 19:15 ` Marek Vasut
  0 siblings, 1 reply; 4+ messages in thread
From: Arvind Yadav @ 2016-12-11 18:01 UTC (permalink / raw)
  To: robert.jarzmik, dwmw2, computersforpeace, boris.brezillon,
	marek.vasut, richard, cyrille.pitchen
  Cc: linux-mtd, linux-kernel

Here, If devm_ioremap will fail. It will return NULL.
Kernel can run into a NULL-pointer dereference.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
---
 drivers/mtd/devices/docg3.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
index b833e6c..013b5b9 100644
--- a/drivers/mtd/devices/docg3.c
+++ b/drivers/mtd/devices/docg3.c
@@ -2083,9 +2083,12 @@ static int __init docg3_probe(struct platform_device *pdev)
 		dev_err(dev, "No I/O memory resource defined\n");
 		return ret;
 	}
-	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
 
 	ret = -ENOMEM;
+	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
+	if (!base)
+		return ret;
+
 	cascade = devm_kzalloc(dev, sizeof(*cascade) * DOC_MAX_NBFLOORS,
 			       GFP_KERNEL);
 	if (!cascade)
-- 
2.7.4

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [V1] mtd: devices: docg3:- Handle return value of devm_ioremap.
  2016-12-11 18:01 [V1] mtd: devices: docg3:- Handle return value of devm_ioremap Arvind Yadav
@ 2016-12-11 19:15 ` Marek Vasut
  2016-12-12  2:59   ` arvind Yadav
  2016-12-12 18:19   ` Fabio Estevam
  0 siblings, 2 replies; 4+ messages in thread
From: Marek Vasut @ 2016-12-11 19:15 UTC (permalink / raw)
  To: Arvind Yadav, robert.jarzmik, dwmw2, computersforpeace,
	boris.brezillon, richard, cyrille.pitchen
  Cc: linux-mtd, linux-kernel

On 12/11/2016 07:01 PM, Arvind Yadav wrote:
> Here, If devm_ioremap will fail. It will return NULL.
> Kernel can run into a NULL-pointer dereference.
> 
> Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
> ---
>  drivers/mtd/devices/docg3.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
> index b833e6c..013b5b9 100644
> --- a/drivers/mtd/devices/docg3.c
> +++ b/drivers/mtd/devices/docg3.c
> @@ -2083,9 +2083,12 @@ static int __init docg3_probe(struct platform_device *pdev)
>  		dev_err(dev, "No I/O memory resource defined\n");
>  		return ret;
>  	}
> -	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
>  
>  	ret = -ENOMEM;
> +	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
> +	if (!base)
> +		return ret;

I think return -ENOMEM right away won't hurt here. Also, dev_err()
explaining the failure would be nice to add.

Thanks!

>  	cascade = devm_kzalloc(dev, sizeof(*cascade) * DOC_MAX_NBFLOORS,
>  			       GFP_KERNEL);
>  	if (!cascade)
> 


-- 
Best regards,
Marek Vasut

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [V1] mtd: devices: docg3:- Handle return value of devm_ioremap.
  2016-12-11 19:15 ` Marek Vasut
@ 2016-12-12  2:59   ` arvind Yadav
  2016-12-12 18:19   ` Fabio Estevam
  1 sibling, 0 replies; 4+ messages in thread
From: arvind Yadav @ 2016-12-12  2:59 UTC (permalink / raw)
  To: Marek Vasut, robert.jarzmik, dwmw2, computersforpeace,
	boris.brezillon, richard, cyrille.pitchen
  Cc: linux-mtd, linux-kernel

Yes, We are returning -ENOMEM, ret is initialized to -ENOMEM.
As per your concern, I have added dev_err failure message.

Thanks
-Arvind

On Monday 12 December 2016 12:45 AM, Marek Vasut wrote:
> On 12/11/2016 07:01 PM, Arvind Yadav wrote:
>> Here, If devm_ioremap will fail. It will return NULL.
>> Kernel can run into a NULL-pointer dereference.
>>
>> Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
>> ---
>>   drivers/mtd/devices/docg3.c | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
>> index b833e6c..013b5b9 100644
>> --- a/drivers/mtd/devices/docg3.c
>> +++ b/drivers/mtd/devices/docg3.c
>> @@ -2083,9 +2083,12 @@ static int __init docg3_probe(struct platform_device *pdev)
>>   		dev_err(dev, "No I/O memory resource defined\n");
>>   		return ret;
>>   	}
>> -	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
>>   
>>   	ret = -ENOMEM;
>> +	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
>> +	if (!base)
>> +		return ret;
> I think return -ENOMEM right away won't hurt here. Also, dev_err()
> explaining the failure would be nice to add.
>
> Thanks!
>
>>   	cascade = devm_kzalloc(dev, sizeof(*cascade) * DOC_MAX_NBFLOORS,
>>   			       GFP_KERNEL);
>>   	if (!cascade)
>>
>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [V1] mtd: devices: docg3:- Handle return value of devm_ioremap.
  2016-12-11 19:15 ` Marek Vasut
  2016-12-12  2:59   ` arvind Yadav
@ 2016-12-12 18:19   ` Fabio Estevam
  1 sibling, 0 replies; 4+ messages in thread
From: Fabio Estevam @ 2016-12-12 18:19 UTC (permalink / raw)
  To: Marek Vasut
  Cc: Arvind Yadav, Robert Jarzmik, David Woodhouse, Brian Norris,
	Boris Brezillon, Richard Weinberger, Cyrille Pitchen, linux-mtd,
	linux-kernel

On Sun, Dec 11, 2016 at 5:15 PM, Marek Vasut <marek.vasut@gmail.com> wrote:

>>       ret = -ENOMEM;
>> +     base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
>> +     if (!base)
>> +             return ret;
>
> I think return -ENOMEM right away won't hurt here. Also, dev_err()
> explaining the failure would be nice to add.

There is no need to add dev_err() message as the mm core will complain
loudly if devm_ioremap() fails.

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2016-12-12 18:19 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2016-12-11 18:01 [V1] mtd: devices: docg3:- Handle return value of devm_ioremap Arvind Yadav
2016-12-11 19:15 ` Marek Vasut
2016-12-12  2:59   ` arvind Yadav
2016-12-12 18:19   ` Fabio Estevam

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