Re: [PATCH 7/9] gpiolib-sysfs: Add gpio name parsing for sysfs export

[Markus Pargmann <mpa@pengutronix.de>]

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On Tue, Jul 28, 2015 at 11:50:04AM +0200, Johan Hovold wrote:
> On Fri, Jul 17, 2015 at 11:32:48AM +0200, Markus Pargmann wrote:
> > Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
> > ---
> >  drivers/gpio/gpiolib-sysfs.c | 41 ++++++++++++++++++++++++++++-------------
> >  1 file changed, 28 insertions(+), 13 deletions(-)
> > 
> > diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
> > index b57ed8e55ab5..c3b74440ca67 100644
> > --- a/drivers/gpio/gpiolib-sysfs.c
> > +++ b/drivers/gpio/gpiolib-sysfs.c
> > @@ -443,18 +443,25 @@ static ssize_t export_store(struct class *class,
> >  				const char *buf, size_t len)
> >  {
> >  	long			gpio;
> > -	struct gpio_desc	*desc;
> > +	struct gpio_desc	*desc = NULL;
> >  	int			status;
> >  
> >  	status = kstrtol(buf, 0, &gpio);
> > -	if (status < 0)
> > -		goto done;
> > +	if (!status)
> > +		desc = gpio_to_desc(gpio);
> >  
> > -	desc = gpio_to_desc(gpio);
> > -	/* reject invalid GPIOs */
> > +	/* Fall back on detection by name */
> >  	if (!desc) {
> > -		pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
> > -		return -EINVAL;
> > +		char *gpio_name = kstrdup(buf, GFP_KERNEL);
> 
> Must check for allocation failures, but why use kstrdup at all?

Yes have to check that.
strim() may modify the buf variable which is constant.

Best regards,

Markus

> 
> > +
> > +		desc = gpio_name_to_desc(strim(gpio_name));
> > +		kfree(gpio_name);
> > +
> > +		/* reject invalid GPIOs */
> > +		if (!desc) {
> > +			pr_warn("%s: invalid GPIO %s\n", __func__, buf);
> > +			return -EINVAL;
> > +		}
> >  	}
> >  
> >  	/* No extra locking here; FLAG_SYSFS just signifies that the
> > @@ -485,17 +492,25 @@ static ssize_t unexport_store(struct class *class,
> >  				const char *buf, size_t len)
> >  {
> >  	long			gpio;
> > -	struct gpio_desc	*desc;
> > +	struct gpio_desc	*desc = NULL;
> >  	int			status;
> >  
> >  	status = kstrtol(buf, 0, &gpio);
> > -	if (status < 0)
> > -		goto done;
> > +	if (!status)
> > +		desc = gpio_to_desc(gpio);
> > +
> > +	/* Fall back on detection by name */
> > +	if (!desc) {
> > +		char *gpio_name = kstrdup(buf, GFP_KERNEL);
> 
> Same here.
> 
> > +
> > +		desc = gpio_name_to_desc(strim(gpio_name));
> > +		kfree(gpio_name);
> > +	}
> > +
> 
> Random whitespace change.
> 
> >  
> > -	desc = gpio_to_desc(gpio);
> >  	/* reject bogus commands (gpio_unexport ignores them) */
> >  	if (!desc) {
> > -		pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
> > +		pr_warn("%s: invalid GPIO %s\n", __func__, buf);
> >  		return -EINVAL;
> >  	}
> 
> Johan
> 

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