Re: [PATCH] fs/userfaultfd.c: simplify the calculation of new_flags

Wei Yang
2019-09-12T02:54:47Z

Ping~

On Tue, Aug 06, 2019 at 01:38:59PM +0800, Wei Yang wrote:
>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@linux.intel.com>
>---
> 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

--
Wei Yang
Help you, Help me