What sections are necessary in a minimal dynamically-linked ELF program?

Question

I assembled a simple "Hello, world" program and linked it using TCC, after which I got 4196 bytes of an executable.

The program has 31 sections: ['', '.text', '.data', '.bss', '.symtab', '.strtab', '.rel.text', '.rodata', '.rodata.cst4', '.note.GNU-stack', '.init', '.rel.init', '.gnu.linkonce.t.__x86.get_pc_thunk.bx', '.fini', '.rel.fini', '.text.unlikely', '.text.__x86.get_pc_thunk.bx', '.eh_frame', '.rel.eh_frame', '.preinit_array', '.init_array', '.fini_array', '.interp', '.dynsym', '.dynstr', '.hash', '.dynamic', '.got', '.plt', '.rel.got', '.shstrtab']. I feel that's a real lot for such a simple binary - which ones are actually necessary here for my program to run?

Here's the source code and the way I compiled it:

        extern printf
        global main

        section .data
msg:    db "Hello World!", 0

        section .text
main:
        ;;  puts (msg)
        push msg
        call printf
        add esp, 4

        ;;  return 0
        mov eax, 0
        ret

nasm main.asm -f elf32 && tcc main.o -o main

Tested on 32bit/ubuntu:16.04 Docker image.

Note: this question is different from this one in that I'm not looking for a tensy Linux ELF, but one that allows me to call dynamic symbols. I believe that due to the nature of dynamic linking, I need some extra sections.

Answer 1

I believe that due to the nature of dynamic linking, I need some extra sections.

Your belief is mistaken. No section is necessary at runtime, only segments matter.

A runnable dynamically-linked ELF binary will have at least one PT_LOAD segment, a PT_INTERP segment, and PT_DYNAMIC segment.