Finally new_flags equals old vm_flags *OR* vm_flags. It is not necessary to mask them first. Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx> --- fs/userfaultfd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index ccbdbd62f0d8..653d8f7c453c 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1457,7 +1457,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, start = vma->vm_start; vma_end = min(end, vma->vm_end); - new_flags = (vma->vm_flags & ~vm_flags) | vm_flags; + new_flags = vma->vm_flags | vm_flags; prev = vma_merge(mm, prev, start, vma_end, new_flags, vma->anon_vma, vma->vm_file, vma->vm_pgoff, vma_policy(vma), -- 2.17.1
