Re: [PATCH 1/2] x86/domctl: cleanup

["Jan Beulich" <JBeulich@suse.com>]

 >>> On 01.04.15 at 17:31, <andrew.cooper3@citrix.com> wrote:
>      case XEN_DOMCTL_gettscinfo:
> -    {
> -        xen_guest_tsc_info_t info;
> -
> -        ret = -EINVAL;
> -        if ( d == current->domain ) /* no domain_pause() */
> -            break;
> -
> -        domain_pause(d);
> -        tsc_get_info(d, &info.tsc_mode,
> -                        &info.elapsed_nsec,
> -                        &info.gtsc_khz,
> -                        &info.incarnation);
> -        if ( copy_to_guest(domctl->u.tsc_info.out_info, &info, 1) )
> -            ret = -EFAULT;
> +        if ( d == currd ) /* no domain_pause() */
> +            ret = -EINVAL;
>          else
> -            ret = 0;
> -        domain_unpause(d);
> -    }
> -    break;
> +        {
> +            xen_guest_tsc_info_t info;
> +
> +            domain_pause(d);
> +            tsc_get_info(d, &info.tsc_mode,
> +                         &info.elapsed_nsec,
> +                         &info.gtsc_khz,
> +                         &info.incarnation);
> +            domain_unpause(d);
> +            copyback = 1;

If you want to use "copyback" here, you need to pass pointers into
domctl->u.tsc_info.out_info to tsc_get_info().

Jan