[PATCH RFC 05/24] userfaultfd: wp: add helper for writeprotect check

[Peter Xu]

From: Shaohua Li <s...@fb.com>

add helper for writeprotect check. Will use it later.

Cc: Andrea Arcangeli <aarca...@redhat.com>
Cc: Pavel Emelyanov <xe...@parallels.com>
Cc: Rik van Riel <r...@redhat.com>
Cc: Kirill A. Shutemov <kir...@shutemov.name>
Cc: Mel Gorman <mgor...@suse.de>
Cc: Hugh Dickins <hu...@google.com>
Cc: Johannes Weiner <han...@cmpxchg.org>
Signed-off-by: Shaohua Li <s...@fb.com>
Signed-off-by: Andrea Arcangeli <aarca...@redhat.com>
Signed-off-by: Peter Xu <pet...@redhat.com>
---
 include/linux/userfaultfd_k.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index 37c9eba75c98..38f748e7186e 100644
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -50,6 +50,11 @@ static inline bool userfaultfd_missing(struct vm_area_struct 
*vma)
        return vma->vm_flags & VM_UFFD_MISSING;
 }
 
+static inline bool userfaultfd_wp(struct vm_area_struct *vma)
+{
+       return vma->vm_flags & VM_UFFD_WP;
+}
+
 static inline bool userfaultfd_armed(struct vm_area_struct *vma)
 {
        return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
@@ -94,6 +99,11 @@ static inline bool userfaultfd_missing(struct vm_area_struct 
*vma)
        return false;
 }
 
+static inline bool userfaultfd_wp(struct vm_area_struct *vma)
+{
+       return false;
+}
+
 static inline bool userfaultfd_armed(struct vm_area_struct *vma)
 {
        return false;
-- 
2.17.1