add: return NULL; }
context: raw_alloc(unsigned int size, int bin_index){	unsigned int new_heap_ptr;	char *retval;	struct heap_page *page;	addr_t addr;	new_heap_ptr = heap_base_ptr + PAGE_ALIGN(size);	if (new_heap_ptr > heap_base + heap_size)		panic("heap overgrew itself!\n");	for (addr = heap_base_ptr; addr < new_heap_ptr; addr += B_PAGE_SIZE) {		page = &heap_alloc_table[(addr - heap_base) / B_PAGE_SIZE];		page->in_use = 1;		page->cleaning = 0;		page->bin_index = bin_index;		if (bin_index < bin_count && bins[bin_index].element_size < B_PAGE_SIZE)			page->free_count = B_PAGE_SIZE / bins[bin_index].element_size;		else			page->free_count = 1;	}	retval = (char *)heap_base_ptr;	heap_base_ptr = new_heap_ptr;	return retval;}