Re: [Qemu-devel] [PATCH 1/4] mm: madvise MADV_USERFAULT

[Andrew Jones <drjones@redhat.com>]

On Mon, May 06, 2013 at 09:56:58PM +0200, Andrea Arcangeli wrote:
> +++ b/mm/madvise.c
> @@ -93,6 +93,21 @@ static long madvise_behavior(struct vm_area_struct * vma,
>  		if (error)
>  			goto out;
>  		break;
> +	case MADV_USERFAULT:
> +		if (vma->vm_ops) {
> +			error = -EINVAL;
> +			goto out;
> +		}
> +		new_flags |= VM_USERFAULT;
> +		break;
> +	case MADV_NOUSERFAULT:
> +		if (vma->vm_ops) {
> +			WARN_ON(new_flags & VM_USERFAULT);
> +			error = -EINVAL;
> +			goto out;
> +		}
> +		new_flags &= ~VM_USERFAULT;
> +		break;
>  	}
>  
>  	if (new_flags == vma->vm_flags) {
> @@ -405,6 +420,7 @@ madvise_behavior_valid(int behavior)
>  	case MADV_HUGEPAGE:
>  	case MADV_NOHUGEPAGE:
>  #endif
> +	case MADV_USERFAULT:

Missing MADV_NOUSERFAULT: here

>  	case MADV_DONTDUMP:
>  	case MADV_DODUMP:
>  		return 1;