Re: [patch 08/13] ptp: Split out PTP_PIN_GETFUNC ioctl code

[Vadim Fedorenko <vadim.fedorenko@linux.dev>]

On 20/06/2025 14:24, Thomas Gleixner wrote:
> Continue the ptp_ioctl() cleanup by splitting out the PTP_PIN_GETFUNC ioctl
> code into a helper function. Convert to lock guard while at it.
> 
> No functional change intended.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
>   drivers/ptp/ptp_chardev.c |   52 ++++++++++++++++++++--------------------------
>   1 file changed, 23 insertions(+), 29 deletions(-)
> 
> --- a/drivers/ptp/ptp_chardev.c
> +++ b/drivers/ptp/ptp_chardev.c
> @@ -396,6 +396,28 @@ static long ptp_sys_offset(struct ptp_cl
>   	return copy_to_user(arg, sysoff, sizeof(*sysoff)) ? -EFAULT : 0;
>   }
>   
> +static long ptp_pin_getfunc(struct ptp_clock *ptp, unsigned int cmd, void __user *arg)
> +{
> +	struct ptp_clock_info *ops = ptp->info;
> +	struct ptp_pin_desc pd;
> +
> +	if (copy_from_user(&pd, arg, sizeof(pd)))
> +		return -EFAULT;
> +
> +	if (cmd == PTP_PIN_GETFUNC2 && !mem_is_zero(pd.rsv, sizeof(pd.rsv)))
> +		return -EINVAL;
> +	else
> +		memset(pd.rsv, 0, sizeof(pd.rsv));
> +
> +	if (pd.index >= ops->n_pins)
> +		return -EINVAL;
> +
> +	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &ptp->pincfg_mux)
> +		pd = ops->pin_config[array_index_nospec(pd.index, ops->n_pins)];
> +
> +	return copy_to_user(arg, &pd, sizeof(pd)) ? -EFAULT : 0;
> +}
> +
>   long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
>   	       unsigned long arg)
>   {
> @@ -451,35 +473,7 @@ long ptp_ioctl(struct posix_clock_contex
>   
>   	case PTP_PIN_GETFUNC:
>   	case PTP_PIN_GETFUNC2:
> -		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
> -			err = -EFAULT;
> -			break;
> -		}
> -		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
> -				|| pd.rsv[3] || pd.rsv[4])
> -			&& cmd == PTP_PIN_GETFUNC2) {
> -			err = -EINVAL;
> -			break;
> -		} else if (cmd == PTP_PIN_GETFUNC) {
> -			pd.rsv[0] = 0;
> -			pd.rsv[1] = 0;
> -			pd.rsv[2] = 0;
> -			pd.rsv[3] = 0;
> -			pd.rsv[4] = 0;
> -		}
> -		pin_index = pd.index;
> -		if (pin_index >= ops->n_pins) {
> -			err = -EINVAL;
> -			break;
> -		}
> -		pin_index = array_index_nospec(pin_index, ops->n_pins);
> -		if (mutex_lock_interruptible(&ptp->pincfg_mux))
> -			return -ERESTARTSYS;
> -		pd = ops->pin_config[pin_index];
> -		mutex_unlock(&ptp->pincfg_mux);
> -		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
> -			err = -EFAULT;
> -		break;
> +		return ptp_pin_getfunc(ptp, cmd, argptr);
>   
>   	case PTP_PIN_SETFUNC:
>   	case PTP_PIN_SETFUNC2:
> 
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>