fixed divine bug amb657, having a misaligned stack would crash on SSE instructions

--HG--
extra : convert_revision : svn%3A39bc706e-5318-0410-9160-8a85361fbb7c/trunk%401172

sourcepawn/jit/x86/jit_x86.cpp

@@ -1608,6 +1608,16 @@ inline void WriteOp_Sysreq_N(JitWriter *jit)
 	//push edx
 	IA32_Push_Reg(jit, AMX_REG_ALT);
 
+	/* Align the stack to 16 bytes */
+	//push ebx
+	//mov ebx, esp
+	//and esp, 0xFFFFFF0
+	//sub esp, 4
+	IA32_Push_Reg(jit, REG_EBX);
+	IA32_Mov_Reg_Rm(jit, REG_EBX, REG_ESP, MOD_REG);
+	IA32_And_Rm_Imm8(jit, REG_ESP, MOD_REG, -16);
+	IA32_Sub_Rm_Imm8(jit, REG_ESP, 4, MOD_REG);
+
 	/* push some callback stuff */
 	//push edi		; stack
 	//push <native>	; native index
@@ -1656,10 +1666,12 @@ inline void WriteOp_Sysreq_N(JitWriter *jit)
 	IA32_Jump_Cond_Imm32_Abs(jit, CC_NZ, data->jit_extern_error);
 
 	/* restore what we damaged */
-	//add esp, 4*3
+	//mov esp, ebx
+	//pop ebx
 	//add edi, ebp
 	//pop edx
-	IA32_Add_Rm_Imm8(jit, REG_ESP, 4*3, MOD_REG);
+	IA32_Mov_Reg_Rm(jit, REG_ESP, REG_EBX, MOD_REG);
+	IA32_Pop_Reg(jit, REG_EBX);
 	IA32_Add_Reg_Rm(jit, AMX_REG_STK, AMX_REG_DAT, MOD_REG);
 	IA32_Pop_Reg(jit, AMX_REG_ALT);
 
@@ -2551,18 +2563,42 @@ SPVM_NATIVE_FUNC JITX86::CreateFakeNative(SPVM_FAKENATIVE_FUNC callback, void *p
 
 	/* First pass, calculate size */
 rewind:
+	/* Align the stack to 16 bytes */
+	//push ebx
+	//push edi
+	//push esi
+	//mov edi, [esp+16]	;store ctx
+	//mov esi, [esp+20]	;store params
+	//mov ebx, esp
+	//and esp, 0xFFFFFF0
+	//sub esp, 4
+	IA32_Push_Reg(jit, REG_EBX);
+	IA32_Push_Reg(jit, REG_EDI);
+	IA32_Push_Reg(jit, REG_ESI);
+	IA32_Mov_Reg_Esp_Disp8(jit, REG_EDI, 16);
+	IA32_Mov_Reg_Esp_Disp8(jit, REG_ESI, 20);
+	IA32_Mov_Reg_Rm(jit, REG_EBX, REG_ESP, MOD_REG);
+	IA32_And_Rm_Imm8(jit, REG_ESP, MOD_REG, -16);
+	IA32_Sub_Rm_Imm8(jit, REG_ESP, 4, MOD_REG);
+
 	//push pData		;push pData
-	//push [esp+12]		;push params
+	//push esi			;push params
-	//push [esp+12]		;push ctx
+	//push edi			;push ctx
 	//call [callback]	;invoke the meta-callback
-	//add esp, 12		;restore the stack
+	//mov esp, ebx		;restore the stack
+	//pop esi			;restore esi
+	//pop edi			;restore edi
+	//pop ebx			;restore ebx
 	//ret				;return
 	IA32_Push_Imm32(jit, (jit_int32_t)pData);
-	IA32_Push_Rm_Disp8_ESP(jit, 12);
+	IA32_Push_Reg(jit, REG_ESI);
-	IA32_Push_Rm_Disp8_ESP(jit, 12);
+	IA32_Push_Reg(jit, REG_EDI);
 	uint32_t call = IA32_Call_Imm32(jit, 0);
 	IA32_Write_Jump32_Abs(jit, call, (void *)callback);
-	IA32_Add_Rm_Imm8(jit, REG_ESP, 12, MOD_REG);
+	IA32_Mov_Reg_Rm(jit, REG_ESP, REG_EBX, MOD_REG);
+	IA32_Pop_Reg(jit, REG_ESI);
+	IA32_Pop_Reg(jit, REG_EDI);
+	IA32_Pop_Reg(jit, REG_EBX);
 	IA32_Return(jit);
 
 	if (jw.outbase == NULL)

sourcepawn/jit/x86/opcode_helpers.cpp

@@ -152,6 +152,7 @@ void Write_BreakDebug(JitWriter *jit)
 	IA32_Cmp_Rm_Disp8_Imm8(jit, AMX_REG_TMP, offsetof(sp_context_t, dbreak), 0);
 	jitoffs_t jmp = IA32_Jump_Cond_Imm8(jit, CC_Z, 0);
 
+	//:TODO: align the stack to 16bytes like in sysreq.x
 	/* NOTE, Hack! PUSHAD pushes EDI last which still has the CIP */
 	//pushad
 	//push [esi+frm]
@@ -414,6 +415,16 @@ void WriteOp_Sysreq_C_Function(JitWriter *jit)
 	//push edx
 	IA32_Push_Reg(jit, AMX_REG_ALT);
 
+	/* Align the stack to 16 bytes */
+	//push ebx
+	//mov ebx, esp
+	//and esp, 0xFFFFFF0
+	//sub esp, 4
+	IA32_Push_Reg(jit, REG_EBX);
+	IA32_Mov_Reg_Rm(jit, REG_EBX, REG_ESP, MOD_REG);
+	IA32_And_Rm_Imm8(jit, REG_ESP, MOD_REG, -16);
+	IA32_Sub_Rm_Imm8(jit, REG_ESP, 4, MOD_REG);
+
 	/* push some callback stuff */
 	//push edi		; stack
 	//push ecx		; native index
@@ -457,10 +468,12 @@ void WriteOp_Sysreq_C_Function(JitWriter *jit)
 	IA32_Jump_Cond_Imm32_Abs(jit, CC_NZ, data->jit_extern_error);
 
 	/* restore what we damaged */
-	//add esp, 4*3
+	//mov esp, ebx
+	//pop ebx
 	//add edi, ebp
 	//pop edx
-	IA32_Add_Rm_Imm8(jit, REG_ESP, 4*3, MOD_REG);
+	IA32_Mov_Reg_Rm(jit, REG_ESP, REG_EBX, MOD_REG);
+	IA32_Pop_Reg(jit, REG_EBX);
 	IA32_Add_Reg_Rm(jit, AMX_REG_STK, AMX_REG_DAT, MOD_REG);
 	IA32_Pop_Reg(jit, AMX_REG_ALT);
 
@@ -641,6 +654,16 @@ void WriteOp_Sysreq_N_Function(JitWriter *jit)
 	IA32_Push_Reg(jit, REG_EAX);
 	IA32_Push_Reg(jit, AMX_REG_ALT);
 
+	/* Align the stack to 16 bytes */
+	//push ebx
+	//mov ebx, esp
+	//and esp, 0xFFFFFF0
+	//sub esp, 4
+	IA32_Push_Reg(jit, REG_EBX);
+	IA32_Mov_Reg_Rm(jit, REG_EBX, REG_ESP, MOD_REG);
+	IA32_And_Rm_Imm8(jit, REG_ESP, MOD_REG, -16);
+	IA32_Sub_Rm_Imm8(jit, REG_ESP, 4, MOD_REG);
+
 	/* push some callback stuff */
 	//push edi		; stack
 	//push ecx		; native index
@@ -684,11 +707,13 @@ void WriteOp_Sysreq_N_Function(JitWriter *jit)
 	IA32_Jump_Cond_Imm32_Abs(jit, CC_NZ, data->jit_extern_error);
 
 	/* restore what we damaged */
-	//add esp, 4*3
+	//mov esp, ebx
+	//pop ebx
 	//add edi, ebp
 	//pop edx
 	//pop ecx	; num_params
-	IA32_Add_Rm_Imm8(jit, REG_ESP, 4*3, MOD_REG);
+	IA32_Mov_Reg_Rm(jit, REG_ESP, REG_EBX, MOD_REG);
+	IA32_Pop_Reg(jit, REG_EBX);
 	IA32_Add_Reg_Rm(jit, AMX_REG_STK, AMX_REG_DAT, MOD_REG);
 	IA32_Pop_Reg(jit, AMX_REG_ALT);
 	IA32_Pop_Reg(jit, REG_ECX);