[PATCH] led: try to get LED's label from the 'label' property

[PATCH] led: try to get LED's label from the 'label' property

[Antony Pavlov]

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
---
 drivers/led/led-gpio.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/led/led-gpio.c b/drivers/led/led-gpio.c
index 7bb3b49..cddac08 100644
--- a/drivers/led/led-gpio.c
+++ b/drivers/led/led-gpio.c
@@ -212,7 +212,9 @@ static int led_gpio_of_probe(struct device_d *dev)
 			continue;
 
 		gled = xzalloc(sizeof(*gled));
-		gled->led.name = xstrdup(child->name);
+		gled->led.name = xstrdup(of_get_property(child, "label", NULL));
+		if (!gled->led.name)
+			gled->led.name = xstrdup(child->name);
 		gled->gpio = gpio;
 		gled->active_low = (flags & OF_GPIO_ACTIVE_LOW) ? 1 : 0;
 
-- 
2.0.1


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Re: [PATCH] led: try to get LED's label from the 'label' property

[Sascha Hauer]

On Sun, Jul 27, 2014 at 12:35:52PM +0400, Antony Pavlov wrote:
> Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
> ---
>  drivers/led/led-gpio.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/led/led-gpio.c b/drivers/led/led-gpio.c
> index 7bb3b49..cddac08 100644
> --- a/drivers/led/led-gpio.c
> +++ b/drivers/led/led-gpio.c
> @@ -212,7 +212,9 @@ static int led_gpio_of_probe(struct device_d *dev)
>  			continue;
>  
>  		gled = xzalloc(sizeof(*gled));
> -		gled->led.name = xstrdup(child->name);
> +		gled->led.name = xstrdup(of_get_property(child, "label", NULL));

When the property doesn't exist you pass NULL to xstrdup. This will
crash. You'll have to add a check or make xstrdup tolerate NULL
pointers.

Sascha

> +		if (!gled->led.name)
> +			gled->led.name = xstrdup(child->name);
>  		gled->gpio = gpio;
>  		gled->active_low = (flags & OF_GPIO_ACTIVE_LOW) ? 1 : 0;
>  
> -- 
> 2.0.1
> 
> 
> _______________________________________________
> barebox mailing list
> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox
> 

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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Re: [PATCH] led: try to get LED's label from the 'label' property

[Antony Pavlov]

On Mon, 28 Jul 2014 07:49:17 +0200
Sascha Hauer <s.hauer@pengutronix.de> wrote:

> On Sun, Jul 27, 2014 at 12:35:52PM +0400, Antony Pavlov wrote:
> > Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
> > ---
> >  drivers/led/led-gpio.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/led/led-gpio.c b/drivers/led/led-gpio.c
> > index 7bb3b49..cddac08 100644
> > --- a/drivers/led/led-gpio.c
> > +++ b/drivers/led/led-gpio.c
> > @@ -212,7 +212,9 @@ static int led_gpio_of_probe(struct device_d *dev)
> >  			continue;
> >  
> >  		gled = xzalloc(sizeof(*gled));
> > -		gled->led.name = xstrdup(child->name);
> > +		gled->led.name = xstrdup(of_get_property(child, "label", NULL));
> 
> When the property doesn't exist you pass NULL to xstrdup. This will
> crash.

My bad. I have seen barebox strdup() realization but missed xstrdup() realization.

Barebox' strdup() can handle NULL argument:

char * strdup(const char *s)
{
        char *new;

        if ((s == NULL) ||
            ((new = malloc (strlen(s) + 1)) == NULL) ) {                         
                return NULL;                                                     
        }

        strcpy (new, s);
        return new;
}

But xstrdup() can't do so:

char *xstrdup(const char *s)
{
        char *p = strdup(s);

        if (!p)
                panic("ERROR: out of memory\n");
        return p;
}               

Can I just change first xstrdup() to strdup() in my patch?

E.g.

-               gled->led.name = xstrdup(of_get_property(child, "label", NULL));
+               gled->led.name = strdup(of_get_property(child, "label", NULL));
                if (!gled->led.name)
                        gled->led.name = xstrdup(child->name);

> You'll have to add a check or make xstrdup tolerate NULL
> pointers.
> 
> Sascha
> 
> > +		if (!gled->led.name)
> > +			gled->led.name = xstrdup(child->name);
> >  		gled->gpio = gpio;
> >  		gled->active_low = (flags & OF_GPIO_ACTIVE_LOW) ? 1 : 0;
> >  
> > -- 
> > 2.0.1
> > 
> > 
> > _______________________________________________
> > barebox mailing list
> > barebox@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/barebox
> > 
> 
> -- 
> Pengutronix e.K.                           |                             |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |


-- 
-- 
Best regards,
  Antony Pavlov

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Re: [PATCH] led: try to get LED's label from the 'label' property

[Sascha Hauer]

On Mon, Jul 28, 2014 at 10:22:43AM +0400, Antony Pavlov wrote:
> On Mon, 28 Jul 2014 07:49:17 +0200
> Sascha Hauer <s.hauer@pengutronix.de> wrote:
> 
> > On Sun, Jul 27, 2014 at 12:35:52PM +0400, Antony Pavlov wrote:
> > > Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
> > > ---
> > >  drivers/led/led-gpio.c | 4 +++-
> > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/led/led-gpio.c b/drivers/led/led-gpio.c
> > > index 7bb3b49..cddac08 100644
> > > --- a/drivers/led/led-gpio.c
> > > +++ b/drivers/led/led-gpio.c
> > > @@ -212,7 +212,9 @@ static int led_gpio_of_probe(struct device_d *dev)
> > >  			continue;
> > >  
> > >  		gled = xzalloc(sizeof(*gled));
> > > -		gled->led.name = xstrdup(child->name);
> > > +		gled->led.name = xstrdup(of_get_property(child, "label", NULL));
> > 
> > When the property doesn't exist you pass NULL to xstrdup. This will
> > crash.
> 
> My bad. I have seen barebox strdup() realization but missed xstrdup() realization.
> 
> Barebox' strdup() can handle NULL argument:
> 
> char * strdup(const char *s)
> {
>         char *new;
> 
>         if ((s == NULL) ||
>             ((new = malloc (strlen(s) + 1)) == NULL) ) {                         
>                 return NULL;                                                     
>         }
> 
>         strcpy (new, s);
>         return new;
> }
> 
> But xstrdup() can't do so:
> 
> char *xstrdup(const char *s)
> {
>         char *p = strdup(s);
> 
>         if (!p)
>                 panic("ERROR: out of memory\n");
>         return p;
> }               
> 
> Can I just change first xstrdup() to strdup() in my patch?

Why not add a NULL pointer check to xstrdup?

> 
> E.g.
> 
> -               gled->led.name = xstrdup(of_get_property(child, "label", NULL));
> +               gled->led.name = strdup(of_get_property(child, "label", NULL));
>                 if (!gled->led.name)
>                         gled->led.name = xstrdup(child->name);

I think this code will raise questions. When reading this code one could
easily ask why stdrup is used in the first place and xstrdup in the
second. A year ahead even we may not know the answer without thinking
about it ;)

Sascha


-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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Re: [PATCH] led: try to get LED's label from the 'label' property

[Sebastian Hesselbarth]

On 07/28/2014 08:22 AM, Antony Pavlov wrote:
> On Mon, 28 Jul 2014 07:49:17 +0200
> Sascha Hauer <s.hauer@pengutronix.de> wrote:
> 
>> On Sun, Jul 27, 2014 at 12:35:52PM +0400, Antony Pavlov wrote:
>>> Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
>>> ---
>>>  drivers/led/led-gpio.c | 4 +++-
>>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/led/led-gpio.c b/drivers/led/led-gpio.c
>>> index 7bb3b49..cddac08 100644
>>> --- a/drivers/led/led-gpio.c
>>> +++ b/drivers/led/led-gpio.c
>>> @@ -212,7 +212,9 @@ static int led_gpio_of_probe(struct device_d *dev)
>>>  			continue;
>>>  
>>>  		gled = xzalloc(sizeof(*gled));
>>> -		gled->led.name = xstrdup(child->name);
>>> +		gled->led.name = xstrdup(of_get_property(child, "label", NULL));
>>
>> When the property doesn't exist you pass NULL to xstrdup. This will
>> crash.
> 
> My bad. I have seen barebox strdup() realization but missed xstrdup() realization.
> 
> Barebox' strdup() can handle NULL argument:
> 
> char * strdup(const char *s)
> {
>         char *new;
> 
>         if ((s == NULL) ||
>             ((new = malloc (strlen(s) + 1)) == NULL) ) {                         
>                 return NULL;                                                     
>         }
> 
>         strcpy (new, s);
>         return new;
> }
> 
> But xstrdup() can't do so:
> 
> char *xstrdup(const char *s)
> {
>         char *p = strdup(s);
> 
>         if (!p)
>                 panic("ERROR: out of memory\n");
>         return p;
> }               
> 
> Can I just change first xstrdup() to strdup() in my patch?
> 
> E.g.
> 
> -               gled->led.name = xstrdup(of_get_property(child, "label", NULL));
> +               gled->led.name = strdup(of_get_property(child, "label", NULL));
>                 if (!gled->led.name)
>                         gled->led.name = xstrdup(child->name);
> 
>> You'll have to add a check or make xstrdup tolerate NULL
>> pointers.
>>

Correct code sequence would probably be:

const char *label;

if (of_property_read_string(child, "label", &label))
	gled->led.name = xstrdup(label);
else
	gled->led.name = xstrdup(child->name);

or

const char *label = child->name;

of_property_read_string(child, "label", &label);
gled->led.name = xstrdup(label);

Sebastian

>>> +		if (!gled->led.name)
>>> +			gled->led.name = xstrdup(child->name);
>>>  		gled->gpio = gpio;
>>>  		gled->active_low = (flags & OF_GPIO_ACTIVE_LOW) ? 1 : 0;
>>>  
>>> -- 
>>> 2.0.1
>>>
>>>
>>> _______________________________________________
>>> barebox mailing list
>>> barebox@lists.infradead.org
>>> http://lists.infradead.org/mailman/listinfo/barebox
>>>
>>
>> -- 
>> Pengutronix e.K.                           |                             |
>> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
>> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
>> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
> 
> 


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Re: [PATCH] led: try to get LED's label from the 'label' property

[Antony Pavlov]

On Mon, 28 Jul 2014 08:29:13 +0200
Sascha Hauer <s.hauer@pengutronix.de> wrote:

> On Mon, Jul 28, 2014 at 10:22:43AM +0400, Antony Pavlov wrote:
> > On Mon, 28 Jul 2014 07:49:17 +0200
> > Sascha Hauer <s.hauer@pengutronix.de> wrote:
> > 
> > > On Sun, Jul 27, 2014 at 12:35:52PM +0400, Antony Pavlov wrote:
> > > > Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
> > > > ---
> > > >  drivers/led/led-gpio.c | 4 +++-
> > > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > > > 
> > > > diff --git a/drivers/led/led-gpio.c b/drivers/led/led-gpio.c
> > > > index 7bb3b49..cddac08 100644
> > > > --- a/drivers/led/led-gpio.c
> > > > +++ b/drivers/led/led-gpio.c
> > > > @@ -212,7 +212,9 @@ static int led_gpio_of_probe(struct device_d *dev)
> > > >  			continue;
> > > >  
> > > >  		gled = xzalloc(sizeof(*gled));
> > > > -		gled->led.name = xstrdup(child->name);
> > > > +		gled->led.name = xstrdup(of_get_property(child, "label", NULL));
> > > 
> > > When the property doesn't exist you pass NULL to xstrdup. This will
> > > crash.
> > 
> > My bad. I have seen barebox strdup() realization but missed xstrdup() realization.
> > 
> > Barebox' strdup() can handle NULL argument:
> > 
> > char * strdup(const char *s)
> > {
> >         char *new;
> > 
> >         if ((s == NULL) ||
> >             ((new = malloc (strlen(s) + 1)) == NULL) ) {                         
> >                 return NULL;                                                     
> >         }
> > 
> >         strcpy (new, s);
> >         return new;
> > }
> > 
> > But xstrdup() can't do so:
> > 
> > char *xstrdup(const char *s)
> > {
> >         char *p = strdup(s);
> > 
> >         if (!p)
> >                 panic("ERROR: out of memory\n");
> >         return p;
> > }               
> > 
> > Can I just change first xstrdup() to strdup() in my patch?
> 
> Why not add a NULL pointer check to xstrdup?

This will be duplication of code. strdup() inside xstrdup() check it too.

> > 
> > E.g.
> > 
> > -               gled->led.name = xstrdup(of_get_property(child, "label", NULL));
> > +               gled->led.name = strdup(of_get_property(child, "label", NULL));
> >                 if (!gled->led.name)
> >                         gled->led.name = xstrdup(child->name);
> 
> I think this code will raise questions. When reading this code one could
> easily ask why stdrup is used in the first place and xstrdup in the
> second. A year ahead even we may not know the answer without thinking
> about it ;)
> 
> Sascha
> 
> 
> -- 
> Pengutronix e.K.                           |                             |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |


-- 
-- 
Best regards,
  Antony Pavlov

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Re: [PATCH] led: try to get LED's label from the 'label' property

[Antony Pavlov]

On Mon, 28 Jul 2014 08:34:43 +0200
Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> wrote:

> On 07/28/2014 08:22 AM, Antony Pavlov wrote:
> > On Mon, 28 Jul 2014 07:49:17 +0200
> > Sascha Hauer <s.hauer@pengutronix.de> wrote:
> > 
> >> On Sun, Jul 27, 2014 at 12:35:52PM +0400, Antony Pavlov wrote:
> >>> Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
> >>> ---

> >>>  drivers/led/led-gpio.c | 4 +++-
> >>>  1 file changed, 3 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/drivers/led/led-gpio.c b/drivers/led/led-gpio.c
> >>> index 7bb3b49..cddac08 100644
> >>> --- a/drivers/led/led-gpio.c
> >>> +++ b/drivers/led/led-gpio.c
> >>> @@ -212,7 +212,9 @@ static int led_gpio_of_probe(struct device_d *dev)
> >>>  			continue;
> >>>  
> >>>  		gled = xzalloc(sizeof(*gled));
> >>> -		gled->led.name = xstrdup(child->name);
> >>> +		gled->led.name = xstrdup(of_get_property(child, "label", NULL));
> >>
> >> When the property doesn't exist you pass NULL to xstrdup. This will
> >> crash.
> > 
> > My bad. I have seen barebox strdup() realization but missed xstrdup() realization.
> > 
> > Barebox' strdup() can handle NULL argument:
> > 
> > char * strdup(const char *s)
> > {
> >         char *new;
> > 
> >         if ((s == NULL) ||
> >             ((new = malloc (strlen(s) + 1)) == NULL) ) {                         
> >                 return NULL;                                                     
> >         }
> > 
> >         strcpy (new, s);
> >         return new;
> > }
> > 
> > But xstrdup() can't do so:
> > 
> > char *xstrdup(const char *s)
> > {
> >         char *p = strdup(s);
> > 
> >         if (!p)
> >                 panic("ERROR: out of memory\n");
> >         return p;
> > }               
> > 
> > Can I just change first xstrdup() to strdup() in my patch?
> > 
> > E.g.
> > 
> > -               gled->led.name = xstrdup(of_get_property(child, "label", NULL));
> > +               gled->led.name = strdup(of_get_property(child, "label", NULL));
> >                 if (!gled->led.name)
> >                         gled->led.name = xstrdup(child->name);
> > 
> >> You'll have to add a check or make xstrdup tolerate NULL
> >> pointers.
> >>
> 
> Correct code sequence would probably be:
> 
> const char *label;
> 
> if (of_property_read_string(child, "label", &label))
> 	gled->led.name = xstrdup(label);
> else
> 	gled->led.name = xstrdup(child->name);

Hmm. of_property_read_string() returns 0 on success...

> 
> or
> 
> const char *label = child->name;
> 
> of_property_read_string(child, "label", &label);
> gled->led.name = xstrdup(label);
> 
> Sebastian
> 
> >>> +		if (!gled->led.name)
> >>> +			gled->led.name = xstrdup(child->name);
> >>>  		gled->gpio = gpio;
> >>>  		gled->active_low = (flags & OF_GPIO_ACTIVE_LOW) ? 1 : 0;
> >>>  
> >>> -- 
> >>> 2.0.1
> >>>
> >>>
> >>> _______________________________________________
> >>> barebox mailing list
> >>> barebox@lists.infradead.org
> >>> http://lists.infradead.org/mailman/listinfo/barebox
> >>>
> >>
> >> -- 
> >> Pengutronix e.K.                           |                             |
> >> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> >> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> >> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
> > 
> > 
> 


-- 
-- 
Best regards,
  Antony Pavlov

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