How to strip seemingly unnecessary zeroes generated by gas?


I'm trying to make a truly minimal shared "library" that has the least possible size it can be:


.globl test
        movb $1, %al
        movb $1, %dil
        movabs $message, %rsi
        movb $7, %dl
        .ascii "hello"

compiling with: gcc -o -fPIC -shared -m64 -nostdlib -s -O3 test.s

And the output is still relatively huge: 4.8KB!! When I look into the binary with radare I can see that after the .text section there are LOTS AND LOTS of seemingly unnecessary code caves produced my gas.

     ;-- section_end..rela.dyn:
            ;-- section..text:
            ;-- test:
/ (fcn) entry0 20
|   entry0 ();
|           0x00000268      b001           mov al, 1                   ; [6] va=0x00000268 pa=0x00000268 sz=25 vsz=25 rwx=--r-x .text
|           0x0000026a      40b701         mov dil, 1
|           0x0000026d      48be7c020000.  movabs rsi, 0x27c           ; "hello"  ; RELOC 64 
|           0x00000277      b207           mov dl, 7
|           0x00000279      0f05           syscall
\           0x0000027b      c3             ret
            ; DATA XREF from 0x0000026d (entry0)
            0x0000027c      68656c6c6f     push 0x6f6c6c65
            ;-- section_end..text:
            0x00000281      0000           add byte [rax], al
            0x00000283      0000           add byte [rax], al
            0x00000285      0000           add byte [rax], al
            ;-- section..eh_frame:
            ;-- section_end..eh_frame:
            ;-- section_end.LOAD0:
            0x00000287  ~   0000           add byte [rax], al
            0x00000289      0000           add byte [rax], al
            0x0000028b      0000           add byte [rax], al
            0x0000028d      0000           add byte [rax], al
            0x0000028f      0000           add byte [rax], al
            0x00000291      0000           add byte [rax], al
            ............ and so on, wasting lots of kilobytes......

What are these for, and how can I get rid of them (If I can/shall)?


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