attach_vma
if (attach_vma(mm, vma)) {
int attach_vma(struct mm_struct *mm, struct vm_area_struct *vma);
ASSERT_FALSE(attach_vma(&mm, vma_left));
ASSERT_FALSE(attach_vma(&mm, vma_right));
ASSERT_FALSE(attach_vma(&mm, init_vma));
ASSERT_FALSE(attach_vma(&mm, vma));
ASSERT_FALSE(attach_vma(&mm, vma));