if s.Flags&SHF_COMPRESSED == 0 {
			s.ReaderAt = s.sr
			s.Size = s.FileSize
		} else {
			// Read the compression header.
			switch f.Class {
			case ELFCLASS32:
				var ch Chdr32
				chdata := make([]byte, unsafe.Sizeof(ch))
				if _, err := s.sr.ReadAt(chdata, 0); err != nil {
					return nil, err
				}
				s.compressionType = CompressionType(bo.Uint32(chdata[unsafe.Offsetof(ch.Type):]))