Re: [PATCH 4/4] pinctrl/abx500: destroy mutex if returning earlydue to error

From: Stephen Warren
Date: Thu Jan 31 2013 - 12:28:38 EST


On 01/31/2013 01:01 AM, Lee Jones wrote:
> On Wed, 30 Jan 2013, Stephen Warren wrote:
>
>> On 01/30/2013 12:40 PM, Linus Walleij wrote:
>>> From: Lee Jones <lee.jones@xxxxxxxxxx>
>>>
>>> Current failure path neglects to mutex_destroy() before returning
>>> an error due to an invalid parameter or an error received from
>>> gpiochip_add(). This patch aims to remedy that behaviour.
>>
>>> diff --git a/drivers/pinctrl/pinctrl-abx500.c b/drivers/pinctrl/pinctrl-abx500.c
>>
>>> @@ -1155,11 +1155,13 @@ static int abx500_gpio_probe(struct platform_device *pdev)
>>> default:
>>> dev_err(&pdev->dev, "Unsupported pinctrl sub driver (%d)\n",
>>> (int) platid->driver_data);
>>> + mutex_destroy(&pct->lock);
>>> return -EINVAL;
>>
>> Especially given there's already a label out_free which performs this
>> mutex_destroy(), those last two lines would be better as:
>>
>> ret = -EINVAL;
>> goto out_free;
>
> Yes, that's one way of doing it. I figured it was 6 of one and half a
> dozen of the other to be honest.
>
> Either I:
>
> + mutex_destroy(&pct->lock);
>
> Or:
>
> + ret = -EINVAL;
> + goto out_free;
> - return -EINVAL;
>
> I figured the smallest diff would be best. To be honest, I'm not
> bothered either way. If it offends you, I can do it the other way, no
> problem. Just let me know quick, so I can get the fixed up patch to
> Linus.
>
> NB: There is no 'out_free:' at this point, it has already been
> removed.

Where has it been removed? Both the latest linux-next and LinusW's
pinctrl tree on git.kernel.org still contain it...

The style in that code is clearly "goto foo" for error-handling, and
makes for smaller simpler code, so I don't see why the label would be
removed.

Still, this review is just a suggestion; this driver isn't anything I
have any ownership of, so I guess feel free to go either way.
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