Problem about SGI-STL V3.3/stl_alloc.h __default_alloc_template::_S_chunk_alloc

[kagtag]

SGI-STL/SGI-STL V3.3/stl_alloc.h

Lines 450 to 456 in be34aac

	if (__bytes_left > 0) {
	_Obj* __STL_VOLATILE* __my_free_list =
	_S_free_list + _S_freelist_index(__bytes_left);
	((_Obj*)_S_start_free) -> _M_free_list_link = *__my_free_list;
	*__my_free_list = (_Obj*)_S_start_free;
	}

I think this logic is only correct when __bytes_left is a multiple of 8,
otherwise, __bytes_left would be less than the chunk size of the computed slot.
For example, if __bytes_left is 5, the computed slot is 0, with chunk size of 8, if caller function requests 7 bytes of memory, normally allocator returns 8 bytes of memory, but this chunk has only 5, which would be not enough.

[ghost]

You can check the malloc logic. When you malloc size of N , the N has adjust to multiple of 8 before malloc.