linux - Any data within segment boundaries however out of section

Question

Two perspectives used in ELF format: segments and sections.

Is it guaranteed for segments perspective to see file's all data when using this perspective?

Is it guaranteed for sections perspective to see file's all data when using this perspective?

In other words:

Can valid ELF format file/image include data located within boundaries of that file certain section however out of boundaries of that file all segments (to belong to no segment of that file)?

Can valid ELF format file/image include data located within boundaries of that file certain segment however out of boundaries of that file all sections (to belong to no section of that file)?

Please fade out in your considerations ELF header, programs header table and sections header table.

Answer 1

Can valid ELF format file/image include data located within boundaries of that file certain section however out of boundaries of that file all segments (to belong to no segment of that file)?

Yes. This is very common: there is no reason to put non-allocatable sections into any segments. Any file with .debug_line, .debug_info, etc. will have these sections not mapped into any of the segments.

Can valid ELF format file/image include data located within boundaries of that file certain segment however out of boundaries of that file all sections (to belong to no section of that file)?

Yes. The final linked file is not required to have any sections at all (only segments matter at runtime), and you can strip all sections with strip. In such a stripped file, none of the data in any of its segments will belong to any section (as there are no sections to begin with).