The first buffer in the list can be obtained by passing a null pointer in the parameter data. To get the next data buffer the previously returned value must be passed in the data parameter. If there are no more buffer left in the list a null pointer is returned.
If the data parameter is not a null pointer it must be a descriptor for a buffer associated with the section scn . If this is not the case a null pointer is returned. To facilitate error handling elf_getdata also returns a null pointer if the scn parameter is a null pointer.