[U-Boot] [PATCH 1/2] pwm: imx: Prevent NULL pointer dereference

[Stefano Babic]

Hi Axel,

On 23/05/2015 09:16, Axel Lin wrote:
> pwm_id_to_reg() can return NULL, so add NULL testing to prevent NULL pointer
> dereference.
> 
> Signed-off-by: Axel Lin <axel.lin at ingics.com>
> ---
>  drivers/pwm/pwm-imx.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
> index 40bf027..47799fc 100644
> --- a/drivers/pwm/pwm-imx.c
> +++ b/drivers/pwm/pwm-imx.c
> @@ -18,6 +18,9 @@ int pwm_init(int pwm_id, int div, int invert)
>  {
>  	struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
>  
> +	if (!pwm)
> +		return -1;
> +
>  	writel(0, &pwm->ir);
>  	return 0;
>  }
> @@ -28,6 +31,9 @@ int pwm_config(int pwm_id, int duty_ns, int period_ns)
>  	unsigned long period_cycles, duty_cycles, prescale;
>  	u32 cr;
>  
> +	if (!pwm)
> +		return -1;
> +
>  	pwm_imx_get_parms(period_ns, duty_ns, &period_cycles, &duty_cycles,
>  			  &prescale);
>  
> @@ -47,6 +53,9 @@ int pwm_enable(int pwm_id)
>  {
>  	struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
>  
> +	if (!pwm)
> +		return -1;
> +
>  	setbits_le32(&pwm->cr, PWMCR_EN);
>  	return 0;
>  }
> @@ -55,5 +64,8 @@ void pwm_disable(int pwm_id)
>  {
>  	struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
>  
> +	if (!pwm)
> +		return;
> +
>  	clrbits_le32(&pwm->cr, PWMCR_EN);
>  }
> 

Right !

Acked-by: Stefano Babic <sbabic at denx.de>

Best regards,
Stefano Babic


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