zyantific · widberg · Dec 6, 2024 · Dec 7, 2024 · Dec 7, 2024
diff --git a/include/Zydis/FormatterBuffer.h b/include/Zydis/FormatterBuffer.h
@@ -182,6 +182,18 @@ typedef struct ZydisFormatterBuffer_
     ZyanString string;
 } ZydisFormatterBuffer;
 
+/**
+ * Defines the `ZydisFormatterBufferState` struct.
+ *
+ * All fields in this struct should be considered as "private". Any changes may
+ * lead to unexpected behavior.
+ */
+typedef struct ZydisFormatterBufferState_
+{
+    ZyanUPointer data;
+    ZyanUSize size;
+} ZydisFormatterBufferState;
+
 /* ---------------------------------------------------------------------------------------------- */
 
 /* ============================================================================================== */
@@ -276,7 +288,7 @@ ZYDIS_EXPORT ZyanStatus ZydisFormatterBufferAppend(ZydisFormatterBuffer* buffer,
  * as the buffer gets overwritten or destroyed.
  */
 ZYDIS_EXPORT ZyanStatus ZydisFormatterBufferRemember(const ZydisFormatterBuffer* buffer,
-    ZyanUPointer* state);
+    ZydisFormatterBufferState* state);
 
 /**
  * Restores a previously saved buffer-state.
@@ -293,7 +305,7 @@ ZYDIS_EXPORT ZyanStatus ZydisFormatterBufferRemember(const ZydisFormatterBuffer*
  * automatically be updated by calling this function.
  */
 ZYDIS_EXPORT ZyanStatus ZydisFormatterBufferRestore(ZydisFormatterBuffer* buffer,
-    ZyanUPointer state);
+    ZydisFormatterBufferState* state);
 
 /* ---------------------------------------------------------------------------------------------- */
 

diff --git a/include/Zydis/Internal/FormatterBase.h b/include/Zydis/Internal/FormatterBase.h
@@ -138,13 +138,11 @@ extern "C" {
  * performance for non-tokenizing passes.
  */
 #define ZYDIS_BUFFER_REMEMBER(buffer, state) \
-    if ((buffer)->is_token_list) \
-    { \
-        (state) = (ZyanUPointer)(buffer)->string.vector.data; \
-    } else \
+    do \
     { \
-        (state) = (ZyanUPointer)(buffer)->string.vector.size; \
-    }
+        (state).data = (ZyanUPointer)(buffer)->string.vector.data; \
+        (state).size = (buffer)->string.vector.size; \
+    } while (0)
 
 /**
  * Appends a string (`STR_`-prefix) or a predefined token-list (`TOK_`-prefix).

diff --git a/include/Zydis/Internal/FormatterIntel.h b/include/Zydis/Internal/FormatterIntel.h
@@ -76,6 +76,15 @@ ZyanStatus ZydisFormatterIntelFormatInstructionMASM(const ZydisFormatter* format
 ZyanStatus ZydisFormatterIntelPrintAddressMASM(const ZydisFormatter* formatter,
     ZydisFormatterBuffer* buffer, ZydisFormatterContext* context);
 
+ZyanStatus ZydisFormatterIntelFormatOperandREGMASM(const ZydisFormatter* formatter,
+    ZydisFormatterBuffer* buffer, ZydisFormatterContext* context);
+
+ZyanStatus ZydisFormatterIntelPrintMnemonicMASM(const ZydisFormatter* formatter,
+    ZydisFormatterBuffer* buffer, ZydisFormatterContext* context);
+
+ZyanStatus ZydisFormatterIntelPrintRegisterMASM(const ZydisFormatter* formatter,
+    ZydisFormatterBuffer* buffer, ZydisFormatterContext* context, ZydisRegister reg);
+
 /* ---------------------------------------------------------------------------------------------- */
 
 /* ============================================================================================== */
@@ -244,12 +253,12 @@ static const ZydisFormatter FORMATTER_INTEL_MASM =
     /* func_format_instruction  */ &ZydisFormatterIntelFormatInstructionMASM,
     /* func_pre_operand         */ ZYAN_NULL,
     /* func_post_operand        */ ZYAN_NULL,
-    /* func_format_operand_reg  */ &ZydisFormatterBaseFormatOperandREG,
+    /* func_format_operand_reg  */ &ZydisFormatterIntelFormatOperandREGMASM,
     /* func_format_operand_mem  */ &ZydisFormatterIntelFormatOperandMEM,
     /* func_format_operand_ptr  */ &ZydisFormatterBaseFormatOperandPTR,
     /* func_format_operand_imm  */ &ZydisFormatterBaseFormatOperandIMM,
-    /* func_print_mnemonic      */ &ZydisFormatterIntelPrintMnemonic,
-    /* func_print_register      */ &ZydisFormatterIntelPrintRegister,
+    /* func_print_mnemonic      */ &ZydisFormatterIntelPrintMnemonicMASM,
+    /* func_print_register      */ &ZydisFormatterIntelPrintRegisterMASM,
     /* func_print_address_abs   */ &ZydisFormatterIntelPrintAddressMASM,
     /* func_print_address_rel   */ &ZydisFormatterIntelPrintAddressMASM,
     /* func_print_disp          */ &ZydisFormatterIntelPrintDISP,

diff --git a/src/FormatterATT.c b/src/FormatterATT.c
@@ -52,7 +52,7 @@ ZyanStatus ZydisFormatterATTFormatInstruction(const ZydisFormatter* formatter,
     ZYAN_CHECK(formatter->func_print_prefixes(formatter, buffer, context));
     ZYAN_CHECK(formatter->func_print_mnemonic(formatter, buffer, context));
 
-    ZyanUPointer state_mnemonic;
+    ZydisFormatterBufferState state_mnemonic;
     ZYDIS_BUFFER_REMEMBER(buffer, state_mnemonic);
 
     const ZyanI8 c = (ZyanI8)context->instruction->operand_count_visible - 1;
@@ -67,10 +67,11 @@ ZyanStatus ZydisFormatterATTFormatInstruction(const ZydisFormatter* formatter,
             continue;
         }
 
-        ZyanUPointer buffer_state;
+        ZydisFormatterBufferState buffer_state;
         ZYDIS_BUFFER_REMEMBER(buffer, buffer_state);
 
-        if (buffer_state != state_mnemonic)
+        if ((buffer_state.data != state_mnemonic.data) ||
+            (buffer_state.size != state_mnemonic.size))
         {
             ZYDIS_BUFFER_APPEND(buffer, DELIM_OPERAND);
         } else
@@ -87,7 +88,7 @@ ZyanStatus ZydisFormatterATTFormatInstruction(const ZydisFormatter* formatter,
             status = formatter->func_pre_operand(formatter, buffer, context);
             if (status == ZYDIS_STATUS_SKIP_TOKEN)
             {
-                ZYAN_CHECK(ZydisFormatterBufferRestore(buffer, buffer_state));
+                ZYAN_CHECK(ZydisFormatterBufferRestore(buffer, &buffer_state));
                 continue;
             }
             if (!ZYAN_SUCCESS(status))
@@ -115,7 +116,7 @@ ZyanStatus ZydisFormatterATTFormatInstruction(const ZydisFormatter* formatter,
         }
         if (status == ZYDIS_STATUS_SKIP_TOKEN)
         {
-            ZYAN_CHECK(ZydisFormatterBufferRestore(buffer, buffer_state));
+            ZYAN_CHECK(ZydisFormatterBufferRestore(buffer, &buffer_state));
             continue;
         }
         if (!ZYAN_SUCCESS(status))
@@ -128,10 +129,10 @@ ZyanStatus ZydisFormatterATTFormatInstruction(const ZydisFormatter* formatter,
             status = formatter->func_post_operand(formatter, buffer, context);
             if (status == ZYDIS_STATUS_SKIP_TOKEN)
             {
-                ZYAN_CHECK(ZydisFormatterBufferRestore(buffer, buffer_state));
+                ZYAN_CHECK(ZydisFormatterBufferRestore(buffer, &buffer_state));
                 continue;
             }
-            if (ZYAN_SUCCESS(status))
+            if (!ZYAN_SUCCESS(status))
             {
                 return status;
             }

diff --git a/src/FormatterBuffer.c b/src/FormatterBuffer.c
@@ -144,25 +144,22 @@ ZyanStatus ZydisFormatterBufferAppend(ZydisFormatterBuffer* buffer, ZydisTokenTy
     return ZYAN_STATUS_SUCCESS;
 }
 
-ZyanStatus ZydisFormatterBufferRemember(const ZydisFormatterBuffer* buffer, ZyanUPointer* state)
+ZyanStatus ZydisFormatterBufferRemember(const ZydisFormatterBuffer* buffer,
+    ZydisFormatterBufferState* state)
 {
     if (!buffer || !state)
     {
         return ZYAN_STATUS_INVALID_ARGUMENT;
     }
 
-    if (buffer->is_token_list)
-    {
-        *state = (ZyanUPointer)buffer->string.vector.data;
-    } else
-    {
-        *state = (ZyanUPointer)buffer->string.vector.size;
-    }
+    state->data = (ZyanUPointer)buffer->string.vector.data;
+    state->size = buffer->string.vector.size;
 
     return ZYAN_STATUS_SUCCESS;
 }
 
-ZyanStatus ZydisFormatterBufferRestore(ZydisFormatterBuffer* buffer, ZyanUPointer state)
+ZyanStatus ZydisFormatterBufferRestore(ZydisFormatterBuffer* buffer,
+    ZydisFormatterBufferState* state)
 {
     if (!buffer)
     {
@@ -171,18 +168,15 @@ ZyanStatus ZydisFormatterBufferRestore(ZydisFormatterBuffer* buffer, ZyanUPointe
 
     if (buffer->is_token_list)
     {
-        const ZyanUSize delta = (ZyanUPointer)buffer->string.vector.data - state;
+        const ZyanUSize delta = (ZyanUPointer)buffer->string.vector.data - state->data;
         buffer->capacity += delta;
-        buffer->string.vector.data = (void*)state;
-        buffer->string.vector.size = 1; // TODO: Restore size?
+        buffer->string.vector.data = (void*)state->data;
         buffer->string.vector.capacity = ZYAN_MIN(buffer->capacity, 255);
-        *(char*)buffer->string.vector.data = '\0';
-    } else
-    {
-        buffer->string.vector.size = (ZyanUSize)state;
-        ZYDIS_STRING_NULLTERMINATE(&buffer->string);
     }
 
+    buffer->string.vector.size = state->size;
+    ZYDIS_STRING_NULLTERMINATE(&buffer->string);
+
     return ZYAN_STATUS_SUCCESS;
 }
 

diff --git a/src/FormatterIntel.c b/src/FormatterIntel.c
@@ -54,7 +54,7 @@ ZyanStatus ZydisFormatterIntelFormatInstruction(const ZydisFormatter* formatter,
     ZYAN_CHECK(formatter->func_print_prefixes(formatter, buffer, context));
     ZYAN_CHECK(formatter->func_print_mnemonic(formatter, buffer, context));
 
-    ZyanUPointer state_mnemonic;
+    ZydisFormatterBufferState state_mnemonic;
     ZYDIS_BUFFER_REMEMBER(buffer, state_mnemonic);
     for (ZyanU8 i = 0; i < context->instruction->operand_count_visible; ++i)
     {
@@ -67,10 +67,11 @@ ZyanStatus ZydisFormatterIntelFormatInstruction(const ZydisFormatter* formatter,
             continue;
         }
 
-        ZyanUPointer buffer_state;
+        ZydisFormatterBufferState buffer_state;
         ZYDIS_BUFFER_REMEMBER(buffer, buffer_state);
 
-        if (buffer_state != state_mnemonic)
+        if ((buffer_state.data != state_mnemonic.data) ||
+            (buffer_state.size != state_mnemonic.size))
         {
             ZYDIS_BUFFER_APPEND(buffer, DELIM_OPERAND);
         } else
@@ -87,7 +88,7 @@ ZyanStatus ZydisFormatterIntelFormatInstruction(const ZydisFormatter* formatter,
             status = formatter->func_pre_operand(formatter, buffer, context);
             if (status == ZYDIS_STATUS_SKIP_TOKEN)
             {
-                ZYAN_CHECK(ZydisFormatterBufferRestore(buffer, buffer_state));
+                ZYAN_CHECK(ZydisFormatterBufferRestore(buffer, &buffer_state));
                 continue;
             }
             if (!ZYAN_SUCCESS(status))
@@ -115,7 +116,7 @@ ZyanStatus ZydisFormatterIntelFormatInstruction(const ZydisFormatter* formatter,
         }
         if (status == ZYDIS_STATUS_SKIP_TOKEN)
         {
-            ZYAN_CHECK(ZydisFormatterBufferRestore(buffer, buffer_state));
+            ZYAN_CHECK(ZydisFormatterBufferRestore(buffer, &buffer_state));
             continue;
         }
         if (!ZYAN_SUCCESS(status))
@@ -128,10 +129,10 @@ ZyanStatus ZydisFormatterIntelFormatInstruction(const ZydisFormatter* formatter,
             status = formatter->func_post_operand(formatter, buffer, context);
             if (status == ZYDIS_STATUS_SKIP_TOKEN)
             {
-                ZYAN_CHECK(ZydisFormatterBufferRestore(buffer, buffer_state));
+                ZYAN_CHECK(ZydisFormatterBufferRestore(buffer, &buffer_state));
                 continue;
             }
-            if (ZYAN_SUCCESS(status))
+            if (!ZYAN_SUCCESS(status))
             {
                 return status;
             }
@@ -408,6 +409,26 @@ ZyanStatus ZydisFormatterIntelFormatInstructionMASM(const ZydisFormatter* format
     // memory operands
     context->runtime_address = 0;
 
+    if (context->instruction->mnemonic == ZYDIS_MNEMONIC_INT3)
+    {
+        ZydisFormatterContext context_copy = *context;
+        ZydisDecodedInstruction instruction;
+        ZydisDecodedOperand operands[1];
+        instruction = *context->instruction;
+        instruction.mnemonic = ZYDIS_MNEMONIC_INT;
+        instruction.operand_count = 1;
+        instruction.operand_count_visible = 1;
+        context_copy.instruction = &instruction;
+        operands[0].type = ZYDIS_OPERAND_TYPE_IMMEDIATE;
+        operands[0].visibility = ZYDIS_OPERAND_VISIBILITY_IMPLICIT;
+        operands[0].imm.is_relative = ZYAN_FALSE;
+        operands[0].imm.is_signed = ZYAN_FALSE;
+        operands[0].imm.value.u = 3;
+        operands[0].imm.size = 8;
+        context_copy.operands = operands;
+        return ZydisFormatterIntelFormatInstruction(formatter, buffer, &context_copy);
+    }
+
     return ZydisFormatterIntelFormatInstruction(formatter, buffer, context);
 }
 
@@ -451,6 +472,58 @@ ZyanStatus ZydisFormatterIntelPrintAddressMASM(const ZydisFormatter* formatter,
     return ZYAN_STATUS_SUCCESS;
 }
 
+ZyanStatus ZydisFormatterIntelFormatOperandREGMASM(const ZydisFormatter* formatter,
+    ZydisFormatterBuffer* buffer, ZydisFormatterContext* context)
+{
+    ZYAN_ASSERT(formatter);
+    ZYAN_ASSERT(buffer);
+    ZYAN_ASSERT(context);
+
+    if ((context->instruction->mnemonic == ZYDIS_MNEMONIC_FUCOMP) && (context->operand->id == 0))
+    {
+        return ZYDIS_STATUS_SKIP_TOKEN;
+    }
+
+    return ZydisFormatterBaseFormatOperandREG(formatter, buffer, context);
+}
+
+ZyanStatus ZydisFormatterIntelPrintMnemonicMASM(const ZydisFormatter* formatter,
+    ZydisFormatterBuffer* buffer, ZydisFormatterContext* context)
+{
+    ZYAN_ASSERT(formatter);
+    ZYAN_ASSERT(buffer);
+    ZYAN_ASSERT(context);
+
+    if (context->instruction->mnemonic == ZYDIS_MNEMONIC_INT1)
+    {
+        ZYDIS_BUFFER_APPEND_CASE(buffer, INVALID_MNEMONIC, formatter->case_mnemonic);
+        return ZYAN_STATUS_SUCCESS;
+    }
+
+    return ZydisFormatterIntelPrintMnemonic(formatter, buffer, context);
+}
+
+ZyanStatus ZydisFormatterIntelPrintRegisterMASM(const ZydisFormatter* formatter,
+    ZydisFormatterBuffer* buffer, ZydisFormatterContext* context, ZydisRegister reg)
+{
+    ZYAN_ASSERT(formatter);
+    ZYAN_ASSERT(buffer);
+    ZYAN_ASSERT(context);
+
+    if ((reg >= ZYDIS_REGISTER_ST0) && (reg <= ZYDIS_REGISTER_ST7))
+    {
+        static const ZydisShortString STR_ST_PREFIX = ZYDIS_MAKE_SHORTSTRING("st(");
+        static const ZyanStringView STR_ST_SUFFIX = ZYAN_DEFINE_STRING_VIEW(")");
+        ZYDIS_BUFFER_APPEND_TOKEN(buffer, ZYDIS_TOKEN_REGISTER);
+        ZYAN_CHECK(ZydisStringAppendShortCase(&buffer->string, &STR_ST_PREFIX,
+            formatter->case_registers));
+        return ZydisStringAppendDecU(&buffer->string, reg - ZYDIS_REGISTER_ST0, 0, ZYAN_NULL,
+            &STR_ST_SUFFIX);
+    }
+
+    return ZydisFormatterIntelPrintRegister(formatter, buffer, context, reg);
+}
+
 /* ---------------------------------------------------------------------------------------------- */
 
 /* ============================================================================================== */
diff --git a/tests/cases/3dnow_000.out b/tests/cases/3dnow_000.out
@@ -1,4 +1,4 @@
-== [    BASIC ] ============================================================================================
+== [      BASIC ] ==========================================================================================
    MNEMONIC: pfsqrt [ENC: 3DNOW, MAP: 0F0F, OPC: 0x97]
      LENGTH:  4
         SSZ: 64
@@ -11,7 +11,7 @@
  ATTRIBUTES: HAS_MODRM ACCEPTS_SEGMENT 
   OPTIMIZED: 0F 0F 37 97 
 
-== [ OPERANDS ] ============================================================================================
+== [   OPERANDS ] ==========================================================================================
 ##       TYPE  VISIBILITY  ACTION      ENCODING   SIZE  NELEM  ELEMSZ  ELEMTYPE                        VALUE
 --  ---------  ----------  ------  ------------   ----  -----  ------  --------  ---------------------------
  0   REGISTER    EXPLICIT      RW     MODRM_REG     64      1      64       INT                          mm6
@@ -23,15 +23,19 @@
                                                                                  DISP  =  0x0000000000000000
 --  ---------  ----------  ------  ------------   ----  -----  ------  --------  ---------------------------
 
-== [      ATT ] ============================================================================================
+== [        ATT ] ==========================================================================================
    ABSOLUTE: pfsqrt (%rdi), %mm6
    RELATIVE: pfsqrt (%rdi), %mm6
 
-== [    INTEL ] ============================================================================================
+== [      INTEL ] ==========================================================================================
    ABSOLUTE: pfsqrt mm6, qword ptr ds:[rdi]
    RELATIVE: pfsqrt mm6, qword ptr ds:[rdi]
 
-== [ SEGMENTS ] ============================================================================================
+== [ INTEL_MASM ] ==========================================================================================
+   ABSOLUTE: pfsqrt mm6, qword ptr ds:[rdi]
+   RELATIVE: pfsqrt mm6, qword ptr ds:[rdi]
+
+== [   SEGMENTS ] ==========================================================================================
 0F 0F 37 97 
 :     :  :..OPCODE
 :     :..MODRM