FEX/unittests/32Bit_ASM/Primary/Primary_E9_2.asm
Ryan Houdek e817f5d98c unittests: Adds 32-bit tests for signed displacement wraparound
A bit meta since it needs to JIT some minor code but easy enough.
Ensures something like #1517 won't happen again.
2022-01-23 18:38:44 -08:00

49 lines
880 B
NASM

%ifdef CONFIG
{
"RegData": {
"RAX": "0x41424344"
},
"Mode": "32BIT"
}
%endif
; Tests for 32-bit signed displacement wrapping
; Testing for overflow specifically
; Will crash or hit the code we emit to memory
; We map ten pages to 0xe000'0000
; Generate a jmp 0x11000 over there
; 0xe9'fb'0f'01'20 : jmp 0x11000
; 0xf4: hlt - Just in case
mov ebx, 0xe0000000
mov al, 0xe9
mov byte [ebx], al
mov eax, 0x20010ffb
mov dword [ebx + 1], eax
mov al, 0xf4
mov byte [ebx + 5], al
; Do a jump dance to stop multiblock from trying to optimize
; Otherwise it will JIT code from 0xe000'0000 before written
lea ebx, [rel next]
jmp ebx
next:
; Move temp to eax to overwrite
mov eax, 0
; This is dependent on where it is in the code!
jmp -0x20000000
; Definitely wrong if we hit here
mov eax, -1
hlt
; This is where the JIT code will land
align 0x1000
mov eax, 0x41424344
hlt