struct vm_struct *area;  size = PAGE_ALIGN(size); if (!size || (size >> PAGE_SHIFT) > num_physpages) return NULL;  area = get_vm_area(size, VM_ALLOC); if (!area) return NULL;  return __vmalloc_area(area, gfp_mask, prot);
return __vmalloc_node(size, gfp_mask, prot, -1);
void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot){	struct vm_struct *area;	size = PAGE_ALIGN(size);	if (!size || (size >> PAGE_SHIFT) > num_physpages)		return NULL;	area = get_vm_area(size, VM_ALLOC);	if (!area)		return NULL;	return __vmalloc_area(area, gfp_mask, prot);}