107 lines
1.4 KiB
NASM
107 lines
1.4 KiB
NASM
.intel_syntax
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push eax
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mov eax,[esp+0x04]
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push ebx
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pushfd
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mov eax,[eax] # get a byte after the call this procedure to analyze what register holds cr ptr
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jmptbl:
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cmp al,0x81
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jz regC
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cmp al,0x82
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jz regD
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cmp al,0x83
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jz regB
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cmp al,0x85
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jz regBP
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cmp al,0x86
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jz regESI
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cmp al,0x87
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jz regEDI
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cmp al,0x88
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jz regA
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cmp al,0x8A
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jz regD
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cmp al,0x8B
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jz regB
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cmp al,0x8D
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jz regBP
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cmp al,0x8E
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jz regESI
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cmp al,0x8F
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jz regEDI
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cmp al,0x90
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jz regA
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cmp al,0x91
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jz regC
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cmp al,0x93
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jz regB
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cmp al,0x95
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jz regBP
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cmp al,0x96
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jz regESI
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cmp al,0x97
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jz regEDI
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jmp fail
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regA:
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mov eax, [esp+0x8]
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mov eax, [eax+0x8c]
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jmp compare
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regC:
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mov eax, [ecx+0x8c]
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jmp compare
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regB:
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mov eax, [ebx+0x8c]
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jmp compare
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regD:
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mov eax, [edx+0x8c]
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jmp compare
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regBP:
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mov eax, [ebp+0x8c]
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jmp compare
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regESI:
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mov eax, [esi+0x8c]
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jmp compare
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regEDI:
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mov eax, [edi+0x8c]
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#jmp compare
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compare:
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push ecx
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mark_racepointer:
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mov ebx,0xDEADBEEF #write a pointer to the list of allowed races
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mark_racecount:
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mov ecx,0xDEADBEEF #write a number of allowed races
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loop1:
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cmp word[ebx+ecx*2],ax
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jz endok
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dec ecx
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cmp ecx ,-1
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jnz loop1
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pop ecx
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popfd
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jmp fail
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endok:
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pop ecx
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popfd
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cmp eax,eax
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jmp endfinal
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fail:
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xor ebx,ebx
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xor eax,eax
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inc eax
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cmp eax,ebx
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endfinal:
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pop ebx
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pop eax
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mark_safeloc1:
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mov [0xDEADBEEF],eax #write a pointer to safe location (usually after this)
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pop eax
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pushfd
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inc eax #skip one instruction
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popfd
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push eax
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mark_safeloc2:
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mov eax,[0xDEADBEEF] #write a pointer to safe location (same as above)
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ret
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