Added test for real self-modifying code

2016-08-14 23:21:38 -07:00
parent 97b10da133
commit 42949408ca
3 changed files with 88 additions and 0 deletions
--- a/tests/regress/x86_self_modifying.s
+++ b/tests/regress/x86_self_modifying.s
@@ -0,0 +1,51 @@
+.intel_syntax noprefix
+
+.global _start
+_start:
+    mov ebp, esp
+    sub ebp, 0x4000
+    mov edx, ebp
+
+    lea esi, [self_modifying]
+    mov edi, ebp
+    mov ecx, 0x2d
+    call memcpy
+    add ebp, 0x2d
+    xor ebx, ebx
+    call edx
+
+    mov eax, 1
+    int 0x80
+
+memcpy:
+    cmp ecx, 0
+    je _end
+    dec ecx
+    mov al, byte ptr [esi+ecx]
+    mov byte ptr [edi+ecx], al
+    jmp memcpy
+
+_end:
+    ret
+
+self_modifying:
+    inc ebx
+    call $+5
+    pop esi
+    dec byte ptr [esi+11]
+    xor edx, edx
+    sub esi, 6
+_loop_start:
+    cmp edx, 5
+    jz _loop_end
+
+    mov edi, ebp
+    mov ecx, 0x2d
+    lea eax, [memcpy]
+    call eax
+    inc edx
+    add ebp, 0x2d
+    mov byte ptr [ebp], 0xc3
+    jmp _loop_start
+
+_loop_end: