re: net: rfkill: gpio: convert to descriptor-based GPIO interface

re: net: rfkill: gpio: convert to descriptor-based GPIO interface

[Dan Carpenter]

Hello Heikki Krogerus,

This is a semi-automatic email about new static checker warnings.

The patch 2111cad655e3: "net: rfkill: gpio: convert to
descriptor-based GPIO interface" from Nov 26, 2013, leads to the
following Smatch complaint:

net/rfkill/rfkill-gpio.c:144 rfkill_gpio_probe()
	 warn: variable dereferenced before check 'rfkill->name' (see line 144)

net/rfkill/rfkill-gpio.c
   111          len = strlen(rfkill->name);
                             ^^^^^^^^^^^^
Dereference.

   112          rfkill->reset_name = devm_kzalloc(&pdev->dev, len + 7, GFP_KERNEL);
   113          if (!rfkill->reset_name)
   114                  return -ENOMEM;
   115  
   116          rfkill->shutdown_name = devm_kzalloc(&pdev->dev, len + 10, GFP_KERNEL);
   117          if (!rfkill->shutdown_name)
   118                  return -ENOMEM;
   119  
   120          snprintf(rfkill->reset_name, len + 6 , "%s_reset", rfkill->name);
   121          snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", rfkill->name);
   122  
   123          rfkill->clk = devm_clk_get(&pdev->dev, clk_name);
   124  
   125          gpio = devm_gpiod_get_index(&pdev->dev, rfkill->reset_name, 0);
   126          if (!IS_ERR(gpio)) {
   127                  ret = gpiod_direction_output(gpio, 0);
   128                  if (ret)
   129                          return ret;
   130                  rfkill->reset_gpio = gpio;
   131          }
   132  
   133          gpio = devm_gpiod_get_index(&pdev->dev, rfkill->shutdown_name, 1);
   134          if (!IS_ERR(gpio)) {
   135                  ret = gpiod_direction_output(gpio, 0);
   136                  if (ret)
   137                          return ret;
   138                  rfkill->shutdown_gpio = gpio;
   139          }
   140  
   141          /* Make sure at-least one of the GPIO is defined and that
   142           * a name is specified for this instance
   143		 */
   144		if ((!rfkill->reset_gpio && !rfkill->shutdown_gpio) || !rfkill->name) {
                                                                        ^^^^^^^^^^^^
The check was originally before the dereference, but the patch moves it
after the dereference.

   145			dev_err(&pdev->dev, "invalid platform data\n");
   146			return -EINVAL;

regards,
dan carpenter

Re: net: rfkill: gpio: convert to descriptor-based GPIO interface

[Heikki Krogerus]

Hi,

On Wed, Jan 08, 2014 at 06:28:38PM +0300, Dan Carpenter wrote:
> Hello Heikki Krogerus,
> 
> This is a semi-automatic email about new static checker warnings.
> 
> The patch 2111cad655e3: "net: rfkill: gpio: convert to
> descriptor-based GPIO interface" from Nov 26, 2013, leads to the
> following Smatch complaint:
> 
> net/rfkill/rfkill-gpio.c:144 rfkill_gpio_probe()
> 	 warn: variable dereferenced before check 'rfkill->name' (see line 144)
> 
> net/rfkill/rfkill-gpio.c
>    111          len = strlen(rfkill->name);
>                              ^^^^^^^^^^^^
> Dereference.
> 
>    112          rfkill->reset_name = devm_kzalloc(&pdev->dev, len + 7, GFP_KERNEL);
>    113          if (!rfkill->reset_name)
>    114                  return -ENOMEM;
>    115  
>    116          rfkill->shutdown_name = devm_kzalloc(&pdev->dev, len + 10, GFP_KERNEL);
>    117          if (!rfkill->shutdown_name)
>    118                  return -ENOMEM;
>    119  
>    120          snprintf(rfkill->reset_name, len + 6 , "%s_reset", rfkill->name);
>    121          snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", rfkill->name);
>    122  
>    123          rfkill->clk = devm_clk_get(&pdev->dev, clk_name);
>    124  
>    125          gpio = devm_gpiod_get_index(&pdev->dev, rfkill->reset_name, 0);
>    126          if (!IS_ERR(gpio)) {
>    127                  ret = gpiod_direction_output(gpio, 0);
>    128                  if (ret)
>    129                          return ret;
>    130                  rfkill->reset_gpio = gpio;
>    131          }
>    132  
>    133          gpio = devm_gpiod_get_index(&pdev->dev, rfkill->shutdown_name, 1);
>    134          if (!IS_ERR(gpio)) {
>    135                  ret = gpiod_direction_output(gpio, 0);
>    136                  if (ret)
>    137                          return ret;
>    138                  rfkill->shutdown_gpio = gpio;
>    139          }
>    140  
>    141          /* Make sure at-least one of the GPIO is defined and that
>    142           * a name is specified for this instance
>    143		 */
>    144		if ((!rfkill->reset_gpio && !rfkill->shutdown_gpio) || !rfkill->name) {
>                                                                         ^^^^^^^^^^^^
> The check was originally before the dereference, but the patch moves it
> after the dereference.
> 
>    145			dev_err(&pdev->dev, "invalid platform data\n");
>    146			return -EINVAL;

OK, this needs to be fixed.

Thanks!

-- 
heikki