From 9d4678eb170c4c632174d1fec8ecee31c2f314f9 Mon Sep 17 00:00:00 2001 From: Andrea Arcangeli Date: Sat, 30 Nov 2019 17:57:58 -0800 Subject: [PATCH] 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 Reported-by: Wei Yang Reviewed-by: Wei Yang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/userfaultfd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index f9fd186..d90c4c5 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -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), -- 2.7.4