Re: [bug report] pinctrl: Add STM32 MCUs support

[Alexandre Torgue <alexandre.torgue@st.com>]

Hi Dan,

On 05/04/2017 08:54 AM, Dan Carpenter wrote:
> Hello Maxime Coquelin,
>
> The patch aceb16dc2da5: "pinctrl: Add STM32 MCUs support" from Jan
> 14, 2016, leads to the following static checker warning:
>
> 	drivers/pinctrl/stm32/pinctrl-stm32.c:801 stm32_pconf_parse_conf()
> 	error: NULL dereference inside function.
>
> drivers/pinctrl/stm32/pinctrl-stm32.c
>    615  static int stm32_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
>    616                          struct pinctrl_gpio_range *range, unsigned gpio,
>    617                          bool input)
>    618  {
>    619          struct stm32_gpio_bank *bank = gpiochip_get_data(range->gc);
>                                                                  ^^^^^^^^^
> This warning only showed up recently because we changed this line to a
> dereference, but it was never valid to pass a NULL range.
>
>    620          int pin = stm32_gpio_pin(gpio);
>    621
>    622          stm32_pmx_set_mode(bank, pin, !input, 0);
>    623
>    624          return 0;
>    625  }
>
> [ snip ]
>
>    768  static int stm32_pconf_parse_conf(struct pinctrl_dev *pctldev,
>    769                  unsigned int pin, enum pin_config_param param,
>    770                  enum pin_config_param arg)
>    771  {
>    772          struct pinctrl_gpio_range *range;
>    773          struct stm32_gpio_bank *bank;
>    774          int offset, ret = 0;
>    775
>    776          range = pinctrl_find_gpio_range_from_pin(pctldev, pin);
>    777          bank = gpiochip_get_data(range->gc);
>    778          offset = stm32_gpio_pin(pin);
>    779
>    780          switch (param) {
>    781          case PIN_CONFIG_DRIVE_PUSH_PULL:
>    782                  stm32_pconf_set_driving(bank, offset, 0);
>    783                  break;
>    784          case PIN_CONFIG_DRIVE_OPEN_DRAIN:
>    785                  stm32_pconf_set_driving(bank, offset, 1);
>    786                  break;
>    787          case PIN_CONFIG_SLEW_RATE:
>    788                  stm32_pconf_set_speed(bank, offset, arg);
>    789                  break;
>    790          case PIN_CONFIG_BIAS_DISABLE:
>    791                  stm32_pconf_set_bias(bank, offset, 0);
>    792                  break;
>    793          case PIN_CONFIG_BIAS_PULL_UP:
>    794                  stm32_pconf_set_bias(bank, offset, 1);
>    795                  break;
>    796          case PIN_CONFIG_BIAS_PULL_DOWN:
>    797                  stm32_pconf_set_bias(bank, offset, 2);
>    798                  break;
>    799          case PIN_CONFIG_OUTPUT:
>    800                  __stm32_gpio_set(bank, offset, arg);
>    801                  ret = stm32_pmx_gpio_set_direction(pctldev, NULL, pin, false);
>                                                                     ^^^^
> A NULL range will Oops.

Yes, I agree. I will send a fix.

regards
Alex

>
>    802                  break;
>    803          default:
>    804                  ret = -EINVAL;
>    805          }
>    806
>    807          return ret;
>    808  }
>
> regards,
> dan carpenter
>