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

[Antony Pavlov <antonynpavlov@gmail.com>]

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
> >>>
> >>>
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> >>>
> >>
> >> -- 
> >> Pengutronix e.K.                           |                             |
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> > 
> > 
> 


-- 
-- 
Best regards,
  Antony Pavlov

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