Re: [PATCH v3 22/28] userfaultfd: wp: enabled write protection in userfaultfd API

[Mike Rapoport]

On Wed, Mar 20, 2019 at 10:06:36AM +0800, Peter Xu wrote:
> From: Shaohua Li <shli@xxxxxx>
> 
> Now it's safe to enable write protection in userfaultfd API
> 
> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
> Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
> Cc: Rik van Riel <riel@xxxxxxxxxx>
> Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
> Cc: Mel Gorman <mgorman@xxxxxxx>
> Cc: Hugh Dickins <hughd@xxxxxxxxxx>
> Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
> Signed-off-by: Shaohua Li <shli@xxxxxx>
> Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
> Reviewed-by: Jerome Glisse <jglisse@xxxxxxxxxx>
> Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>

Reviewed-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>

> ---
>  include/uapi/linux/userfaultfd.h | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h
> index 95c4a160e5f8..e7e98bde221f 100644
> --- a/include/uapi/linux/userfaultfd.h
> +++ b/include/uapi/linux/userfaultfd.h
> @@ -19,7 +19,8 @@
>   * means the userland is reading).
>   */
>  #define UFFD_API ((__u64)0xAA)
> -#define UFFD_API_FEATURES (UFFD_FEATURE_EVENT_FORK |		\
> +#define UFFD_API_FEATURES (UFFD_FEATURE_PAGEFAULT_FLAG_WP |	\
> +			   UFFD_FEATURE_EVENT_FORK |		\
>  			   UFFD_FEATURE_EVENT_REMAP |		\
>  			   UFFD_FEATURE_EVENT_REMOVE |	\
>  			   UFFD_FEATURE_EVENT_UNMAP |		\
> @@ -34,7 +35,8 @@
>  #define UFFD_API_RANGE_IOCTLS			\
>  	((__u64)1 << _UFFDIO_WAKE |		\
>  	 (__u64)1 << _UFFDIO_COPY |		\
> -	 (__u64)1 << _UFFDIO_ZEROPAGE)
> +	 (__u64)1 << _UFFDIO_ZEROPAGE |		\
> +	 (__u64)1 << _UFFDIO_WRITEPROTECT)
>  #define UFFD_API_RANGE_IOCTLS_BASIC		\
>  	((__u64)1 << _UFFDIO_WAKE |		\
>  	 (__u64)1 << _UFFDIO_COPY)
> -- 
> 2.17.1
> 

-- 
Sincerely yours,
Mike.