From: Shaohua Li <shli@xxxxxx> Subject: userfaultfd: wp: enabled write protection in userfaultfd API Now it's safe to enable write protection in userfaultfd API Link: http://lkml.kernel.org/r/20200220163112.11409-15-peterx@xxxxxxxxxx Signed-off-by: Shaohua Li <shli@xxxxxx> Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> Reviewed-by: Jerome Glisse <jglisse@xxxxxxxxxx> Reviewed-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> 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> Cc: Bobby Powers <bobbypowers@xxxxxxxxx> Cc: Brian Geffon <bgeffon@xxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Denis Plotnikov <dplotnikov@xxxxxxxxxxxxx> Cc: "Dr . David Alan Gilbert" <dgilbert@xxxxxxxxxx> Cc: Martin Cracauer <cracauer@xxxxxxxx> Cc: Marty McFadden <mcfadden8@xxxxxxxx> Cc: Maya Gokhale <gokhale2@xxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Pavel Emelyanov <xemul@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/uapi/linux/userfaultfd.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/include/uapi/linux/userfaultfd.h~userfaultfd-wp-enabled-write-protection-in-userfaultfd-api +++ a/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) _