On Mon, Apr 20, 2015 at 01:57:39PM +0800, Baolin Wang wrote:

> @@ -911,18 +907,14 @@ retry:
>               return -EINVAL;
>
>       kc = clockid_to_kclock(timr->it_clock);
> -     if (WARN_ON_ONCE(!kc || (!kc->timer_set && !kc->timer_set64))) {
> +     if (WARN_ON_ONCE(!kc || !kc->timer_set64)) {
>               error = -EINVAL;
>       } else {
> -             if (kc->timer_set64) {
> -                     new_spec64 = itimerspec_to_itimerspec64(new_spec);
> -                     error = kc->timer_set64(timr, flags, &new_spec64,
> -                                             &old_spec64);
> -                     if (old_setting)
> -                             old_spec = itimerspec64_to_itimerspec(old_spec64);
> -             } else {
> -                     error = kc->timer_set(timr, flags, &new_spec, rtn);
> -             }
> +             new_spec64 = itimerspec_to_itimerspec64(new_spec);
> +             error = kc->timer_set64(timr, flags, &new_spec64,
> +                                     &old_spec64);

This statement can fit on one line.

> +             if (old_setting)
> +                     old_spec = itimerspec64_to_itimerspec(old_spec64);
>       }
>
>       unlock_timer(timr, flag);

> @@ -1057,14 +1045,13 @@ SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
>       if (!kc)
>               return -EINVAL;
>
> -     if (kc->clock_get64) {
> -             error = kc->clock_get64(which_clock, &kernel_tp64);
> -             kernel_tp = timespec64_to_timespec(kernel_tp64);
> -     } else {
> -             error = kc->clock_get(which_clock, &kernel_tp);
> -     }
> +     error = kc->clock_get64(which_clock, &kernel_tp64);
> +     if (!error)
> +             return error;

Wrong test, should be: if (error) ...

> +
> +     kernel_tp = timespec64_to_timespec(kernel_tp64);
>
> -     if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))

The (!error && ...) was correct here!

> +     if (copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
>               error = -EFAULT;
>
>       return error;

You can simplify this like so:

        return copy_to_user(tp, &kernel_tp, sizeof(kernel_tp)) ? -EFAULT : 0;

> @@ -1104,14 +1091,13 @@ SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
>       if (!kc)
>               return -EINVAL;
>
> -     if (kc->clock_getres64) {
> -             error = kc->clock_getres64(which_clock, &rtn_tp64);
> -             rtn_tp = timespec64_to_timespec(rtn_tp64);
> -     } else {
> -             error = kc->clock_getres(which_clock, &rtn_tp);
> -     }
> +     error = kc->clock_getres64(which_clock, &rtn_tp64);
> +     if (!error)
> +             return error;

Also wrong.

> +
> +     rtn_tp = timespec64_to_timespec(rtn_tp64);
>
> -     if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp)))
> +     if (tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp)))
>               error = -EFAULT;
>
>       return error;
> --
> 1.7.9.5
>

Thanks,
Richard