static void validate_mm(struct mm_struct *mm)
{
	int bug = 0;
	int i = 0;
	unsigned long highest_address = 0;
	struct vm_area_struct *vma = mm->mmap;

	while (vma) {
		struct anon_vma *anon_vma = vma->anon_vma;
		struct anon_vma_chain *avc;

		if (anon_vma) {
			anon_vma_lock_read(anon_vma);
			list_for_each_entry(avc, &vma->anon_vma_chain, same_vma)
				anon_vma_interval_tree_verify(avc);
			anon_vma_unlock_read(anon_vma);
		}

		highest_address = vm_end_gap(vma);
		vma = vma->vm_next;
		i++;
	}
	if (i != mm->map_count) {
		pr_emerg("map_count %d vm_next %d\n", mm->map_count, i);
		bug = 1;
	}
	if (highest_address != mm->highest_vm_end) {
		pr_emerg("mm->highest_vm_end %lx, found %lx\n",
			  mm->highest_vm_end, highest_address);
		bug = 1;
	}
	i = browse_rb(mm);
	if (i != mm->map_count) {
		if (i != -1)
			pr_emerg("map_count %d rb %d\n", mm->map_count, i);
		bug = 1;
	}
	VM_BUG_ON_MM(bug, mm);
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.