fs/userfaultfd.c: wp: clear VM_UFFD_MISSING or VM_UFFD_WP during userfaultfd_register()

If the registration is repeated without VM_UFFD_MISSING or VM_UFFD_WP they
need to be cleared.  Currently setting UFFDIO_REGISTER_MODE_WP returns
-EINVAL, so this patch is a noop until the UFFDIO_REGISTER_MODE_WP support
is applied.

Link: http://lkml.kernel.org/r/20191004232834.GP13922@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrea Arcangeli 2019-11-30 17:57:58 -08:00 committed by Linus Torvalds
parent 643aa36ead
commit 9d4678eb17
1 changed files with 2 additions and 1 deletions

View File

@ -1460,7 +1460,8 @@ 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_UFFD_MISSING|VM_UFFD_WP)) | vm_flags;
prev = vma_merge(mm, prev, start, vma_end, new_flags,
vma->anon_vma, vma->vm_file, vma->vm_pgoff,
vma_policy(vma),