diff mbox

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

Message ID 1437125570-28623-8-git-send-email-mpa@pengutronix.de (mailing list archive)
State New, archived
Headers show

Commit Message

Markus Pargmann July 17, 2015, 9:32 a.m. UTC 
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
---
 drivers/gpio/gpiolib-sysfs.c | 41 ++++++++++++++++++++++++++++-------------
 1 file changed, 28 insertions(+), 13 deletions(-)

Comments

Johan Hovold July 28, 2015, 9:50 a.m. UTC | #1 
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?

> +
> +		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
Markus Pargmann July 29, 2015, 6:57 a.m. UTC | #2 
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
>
Johan Hovold July 31, 2015, 8:44 a.m. UTC | #3 
On Wed, Jul 29, 2015 at 08:57:36AM +0200, Markus Pargmann wrote:
> 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:

> > > +		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.
>
> > > +
> > > +		desc = gpio_name_to_desc(strim(gpio_name));

Ah, I missed that strim.

Johan
diff mbox

Patch

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);
+
+		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);
+
+		desc = gpio_name_to_desc(strim(gpio_name));
+		kfree(gpio_name);
+	}
+
 
-	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;
 	}
 
@@ -509,7 +524,7 @@  static ssize_t unexport_store(struct class *class,
 		status = 0;
 		gpiod_free(desc);
 	}
-done:
+
 	if (status)
 		pr_debug("%s: status %d\n", __func__, status);
 	return status ? : len;