static void unmap_single_vma(struct mmu_gather *tlb,
		struct vm_area_struct *vma, unsigned long start_addr,
		unsigned long end_addr,
		struct zap_details *details)
{
	unsigned long start = max(vma->vm_start, start_addr);
	unsigned long end;

	if (start >= vma->vm_end)
		return;
	end = min(vma->vm_end, end_addr);
	if (end <= vma->vm_start)
		return;

	if (vma->vm_file)
		uprobe_munmap(vma, start, end);

	if (unlikely(vma->vm_flags & VM_PFNMAP))
		untrack_pfn(vma, 0, 0);

	if (start != end) {
		if (unlikely(is_vm_hugetlb_page(vma))) {
			/*
			 * It is undesirable to test vma->vm_file as it
			 * should be non-null for valid hugetlb area.
			 * However, vm_file will be NULL in the error
			 * cleanup path of do_mmap_pgoff. When
			 * hugetlbfs ->mmap method fails,
			 * do_mmap_pgoff() nullifies vma->vm_file
			 * before calling this function to clean up.
			 * Since no pte has actually been setup, it is
			 * safe to do nothing in this case.
			 */
			if (vma->vm_file) {
				mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
				__unmap_hugepage_range_final(tlb, vma, start, end, NULL);
				mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
			}
		} else
			unmap_page_range(tlb, vma, start, end, details);
	}
}
static void unmap_single_vma(struct mmu_gather *tlb,
		struct vm_area_struct *vma, unsigned long start_addr,
		unsigned long end_addr,
		struct zap_details *details)
{
	unsigned long start = max(vma->vm_start, start_addr);
	unsigned long end;

	if (start >= vma->vm_end)
		return;
	end = min(vma->vm_end, end_addr);
	if (end <= vma->vm_start)
		return;

	if (vma->vm_file)
		uprobe_munmap(vma, start, end);

	if (unlikely(vma->vm_flags & VM_PFNMAP))
		untrack_pfn(vma, 0, 0);

	if (start != end) {
		if (unlikely(is_vm_hugetlb_page(vma))) {
			 
			if (vma->vm_file) {
				mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
				__unmap_hugepage_range_final(tlb, vma, start, end, NULL);
				mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
			}
		} else
			unmap_page_range(tlb, vma, start, end, details);
	}
}