diff mbox

extcon: palmas: Fail gracefully if invalid configuration

Message ID 1481112734-19536-1-git-send-email-rogerq@ti.com
State New
Headers show

Commit Message

Roger Quadros Dec. 7, 2016, 12:12 p.m. UTC
extcon-palmas must be child of palmas and expects parent's
drvdata to be valid. Check for non NULL parent drvdata and
fail if it is NULL. Not doing so will result in a NULL
pointer dereference later in the probe() parent drvdata
is NULL (e.g. misplaced extcon-palmas node in device tree).

Signed-off-by: Roger Quadros <rogerq@ti.com>

---
 drivers/extcon/extcon-palmas.c | 5 +++++
 1 file changed, 5 insertions(+)

-- 
2.7.4

Comments

Chanwoo Choi Dec. 7, 2016, 12:46 p.m. UTC | #1
Hi Roger,

Looks good to me.
But I have some comment.

How about changing the subject as following?

- old : Fail gracefully if invalid configuration
- new : Check the parent instance to prevent the NULL pointer error

On 2016년 12월 07일 21:12, Roger Quadros wrote:
> extcon-palmas must be child of palmas and expects parent's

> drvdata to be valid. Check for non NULL parent drvdata and

> fail if it is NULL. Not doing so will result in a NULL

> pointer dereference later in the probe() parent drvdata

> is NULL (e.g. misplaced extcon-palmas node in device tree).

> 

> Signed-off-by: Roger Quadros <rogerq@ti.com>

> ---

>  drivers/extcon/extcon-palmas.c | 5 +++++

>  1 file changed, 5 insertions(+)

> 

> diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c

> index 634ba70..ec987ab 100644

> --- a/drivers/extcon/extcon-palmas.c

> +++ b/drivers/extcon/extcon-palmas.c

> @@ -190,6 +190,11 @@ static int palmas_usb_probe(struct platform_device *pdev)

>  	struct palmas_usb *palmas_usb;

>  	int status;

>  

> +	if (!palmas) {

> +		dev_err(&pdev->dev, "device has invalid parent\n");


How about changing the error message as following?
because the extcon-palmas used the 'failed to ..' style for error message.
- "failed to get valid parent"

> +		return -EINVAL;

> +	}

> +

>  	palmas_usb = devm_kzalloc(&pdev->dev, sizeof(*palmas_usb), GFP_KERNEL);

>  	if (!palmas_usb)

>  		return -ENOMEM;

> 



Best Regards,
Chanwoo Choi
Roger Quadros Dec. 8, 2016, 8:26 a.m. UTC | #2
Hi Chanwoo,

On 07/12/16 14:46, Chanwoo Choi wrote:
> Hi Roger,

> 

> Looks good to me.

> But I have some comment.

> 

> How about changing the subject as following?

> 

> - old : Fail gracefully if invalid configuration

> - new : Check the parent instance to prevent the NULL pointer error


I'm OK with this.

> 

> On 2016년 12월 07일 21:12, Roger Quadros wrote:

>> extcon-palmas must be child of palmas and expects parent's

>> drvdata to be valid. Check for non NULL parent drvdata and

>> fail if it is NULL. Not doing so will result in a NULL

>> pointer dereference later in the probe() parent drvdata

>> is NULL (e.g. misplaced extcon-palmas node in device tree).

>>

>> Signed-off-by: Roger Quadros <rogerq@ti.com>

>> ---

>>  drivers/extcon/extcon-palmas.c | 5 +++++

>>  1 file changed, 5 insertions(+)

>>

>> diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c

>> index 634ba70..ec987ab 100644

>> --- a/drivers/extcon/extcon-palmas.c

>> +++ b/drivers/extcon/extcon-palmas.c

>> @@ -190,6 +190,11 @@ static int palmas_usb_probe(struct platform_device *pdev)

>>  	struct palmas_usb *palmas_usb;

>>  	int status;

>>  

>> +	if (!palmas) {

>> +		dev_err(&pdev->dev, "device has invalid parent\n");

> 

> How about changing the error message as following?

> because the extcon-palmas used the 'failed to ..' style for error message.

> - "failed to get valid parent"


This is also fine.

I'll send a v2.

> 

>> +		return -EINVAL;

>> +	}

>> +

>>  	palmas_usb = devm_kzalloc(&pdev->dev, sizeof(*palmas_usb), GFP_KERNEL);

>>  	if (!palmas_usb)

>>  		return -ENOMEM;

>>

> 

> 


--
cheers,
-roger
diff mbox

Patch

diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
index 634ba70..ec987ab 100644
--- a/drivers/extcon/extcon-palmas.c
+++ b/drivers/extcon/extcon-palmas.c
@@ -190,6 +190,11 @@  static int palmas_usb_probe(struct platform_device *pdev)
 	struct palmas_usb *palmas_usb;
 	int status;
 
+	if (!palmas) {
+		dev_err(&pdev->dev, "device has invalid parent\n");
+		return -EINVAL;
+	}
+
 	palmas_usb = devm_kzalloc(&pdev->dev, sizeof(*palmas_usb), GFP_KERNEL);
 	if (!palmas_usb)
 		return -ENOMEM;