mirror of
				https://github.com/c64scene-ar/llvm-6502.git
				synced 2025-10-31 08:16:47 +00:00 
			
		
		
		
	git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166945 91177308-0d34-0410-b5e6-96231b3b80d8
		
			
				
	
	
		
			1664 lines
		
	
	
		
			50 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			1664 lines
		
	
	
		
			50 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*===-- X86DisassemblerDecoder.c - Disassembler decoder ------------*- C -*-===*
 | |
|  *
 | |
|  *                     The LLVM Compiler Infrastructure
 | |
|  *
 | |
|  * This file is distributed under the University of Illinois Open Source
 | |
|  * License. See LICENSE.TXT for details.
 | |
|  *
 | |
|  *===----------------------------------------------------------------------===*
 | |
|  *
 | |
|  * This file is part of the X86 Disassembler.
 | |
|  * It contains the implementation of the instruction decoder.
 | |
|  * Documentation for the disassembler can be found in X86Disassembler.h.
 | |
|  *
 | |
|  *===----------------------------------------------------------------------===*/
 | |
| 
 | |
| #include <stdarg.h>   /* for va_*()       */
 | |
| #include <stdio.h>    /* for vsnprintf()  */
 | |
| #include <stdlib.h>   /* for exit()       */
 | |
| #include <string.h>   /* for memset()     */
 | |
| 
 | |
| #include "X86DisassemblerDecoder.h"
 | |
| 
 | |
| #include "X86GenDisassemblerTables.inc"
 | |
| 
 | |
| #define TRUE  1
 | |
| #define FALSE 0
 | |
| 
 | |
| typedef int8_t bool;
 | |
| 
 | |
| #ifndef NDEBUG
 | |
| #define debug(s) do { x86DisassemblerDebug(__FILE__, __LINE__, s); } while (0)
 | |
| #else
 | |
| #define debug(s) do { } while (0)
 | |
| #endif
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * contextForAttrs - Client for the instruction context table.  Takes a set of
 | |
|  *   attributes and returns the appropriate decode context.
 | |
|  *
 | |
|  * @param attrMask  - Attributes, from the enumeration attributeBits.
 | |
|  * @return          - The InstructionContext to use when looking up an
 | |
|  *                    an instruction with these attributes.
 | |
|  */
 | |
| static InstructionContext contextForAttrs(uint8_t attrMask) {
 | |
|   return CONTEXTS_SYM[attrMask];
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * modRMRequired - Reads the appropriate instruction table to determine whether
 | |
|  *   the ModR/M byte is required to decode a particular instruction.
 | |
|  *
 | |
|  * @param type        - The opcode type (i.e., how many bytes it has).
 | |
|  * @param insnContext - The context for the instruction, as returned by
 | |
|  *                      contextForAttrs.
 | |
|  * @param opcode      - The last byte of the instruction's opcode, not counting
 | |
|  *                      ModR/M extensions and escapes.
 | |
|  * @return            - TRUE if the ModR/M byte is required, FALSE otherwise.
 | |
|  */
 | |
| static int modRMRequired(OpcodeType type,
 | |
|                          InstructionContext insnContext,
 | |
|                          uint8_t opcode) {
 | |
|   const struct ContextDecision* decision = 0;
 | |
|   
 | |
|   switch (type) {
 | |
|   case ONEBYTE:
 | |
|     decision = &ONEBYTE_SYM;
 | |
|     break;
 | |
|   case TWOBYTE:
 | |
|     decision = &TWOBYTE_SYM;
 | |
|     break;
 | |
|   case THREEBYTE_38:
 | |
|     decision = &THREEBYTE38_SYM;
 | |
|     break;
 | |
|   case THREEBYTE_3A:
 | |
|     decision = &THREEBYTE3A_SYM;
 | |
|     break;
 | |
|   case THREEBYTE_A6:
 | |
|     decision = &THREEBYTEA6_SYM;
 | |
|     break;
 | |
|   case THREEBYTE_A7:
 | |
|     decision = &THREEBYTEA7_SYM;
 | |
|     break;
 | |
|   }
 | |
| 
 | |
|   return decision->opcodeDecisions[insnContext].modRMDecisions[opcode].
 | |
|     modrm_type != MODRM_ONEENTRY;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * decode - Reads the appropriate instruction table to obtain the unique ID of
 | |
|  *   an instruction.
 | |
|  *
 | |
|  * @param type        - See modRMRequired().
 | |
|  * @param insnContext - See modRMRequired().
 | |
|  * @param opcode      - See modRMRequired().
 | |
|  * @param modRM       - The ModR/M byte if required, or any value if not.
 | |
|  * @return            - The UID of the instruction, or 0 on failure.
 | |
|  */
 | |
| static InstrUID decode(OpcodeType type,
 | |
|                        InstructionContext insnContext,
 | |
|                        uint8_t opcode,
 | |
|                        uint8_t modRM) {
 | |
|   const struct ModRMDecision* dec = 0;
 | |
|   
 | |
|   switch (type) {
 | |
|   case ONEBYTE:
 | |
|     dec = &ONEBYTE_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
 | |
|     break;
 | |
|   case TWOBYTE:
 | |
|     dec = &TWOBYTE_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
 | |
|     break;
 | |
|   case THREEBYTE_38:
 | |
|     dec = &THREEBYTE38_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
 | |
|     break;
 | |
|   case THREEBYTE_3A:
 | |
|     dec = &THREEBYTE3A_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
 | |
|     break;
 | |
|   case THREEBYTE_A6:
 | |
|     dec = &THREEBYTEA6_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
 | |
|     break;
 | |
|   case THREEBYTE_A7:
 | |
|     dec = &THREEBYTEA7_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
 | |
|     break;
 | |
|   }
 | |
|   
 | |
|   switch (dec->modrm_type) {
 | |
|   default:
 | |
|     debug("Corrupt table!  Unknown modrm_type");
 | |
|     return 0;
 | |
|   case MODRM_ONEENTRY:
 | |
|     return modRMTable[dec->instructionIDs];
 | |
|   case MODRM_SPLITRM:
 | |
|     if (modFromModRM(modRM) == 0x3)
 | |
|       return modRMTable[dec->instructionIDs+1];
 | |
|     return modRMTable[dec->instructionIDs];
 | |
|   case MODRM_SPLITREG:
 | |
|     if (modFromModRM(modRM) == 0x3)
 | |
|       return modRMTable[dec->instructionIDs+((modRM & 0x38) >> 3)+8];
 | |
|     return modRMTable[dec->instructionIDs+((modRM & 0x38) >> 3)];
 | |
|   case MODRM_SPLITMISC:
 | |
|     if (modFromModRM(modRM) == 0x3)
 | |
|       return modRMTable[dec->instructionIDs+(modRM & 0x3f)+8];
 | |
|     return modRMTable[dec->instructionIDs+((modRM & 0x38) >> 3)];
 | |
|   case MODRM_FULL:
 | |
|     return modRMTable[dec->instructionIDs+modRM];
 | |
|   }
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * specifierForUID - Given a UID, returns the name and operand specification for
 | |
|  *   that instruction.
 | |
|  *
 | |
|  * @param uid - The unique ID for the instruction.  This should be returned by
 | |
|  *              decode(); specifierForUID will not check bounds.
 | |
|  * @return    - A pointer to the specification for that instruction.
 | |
|  */
 | |
| static const struct InstructionSpecifier *specifierForUID(InstrUID uid) {
 | |
|   return &INSTRUCTIONS_SYM[uid];
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * consumeByte - Uses the reader function provided by the user to consume one
 | |
|  *   byte from the instruction's memory and advance the cursor.
 | |
|  *
 | |
|  * @param insn  - The instruction with the reader function to use.  The cursor
 | |
|  *                for this instruction is advanced.
 | |
|  * @param byte  - A pointer to a pre-allocated memory buffer to be populated
 | |
|  *                with the data read.
 | |
|  * @return      - 0 if the read was successful; nonzero otherwise.
 | |
|  */
 | |
| static int consumeByte(struct InternalInstruction* insn, uint8_t* byte) {
 | |
|   int ret = insn->reader(insn->readerArg, byte, insn->readerCursor);
 | |
|   
 | |
|   if (!ret)
 | |
|     ++(insn->readerCursor);
 | |
|   
 | |
|   return ret;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * lookAtByte - Like consumeByte, but does not advance the cursor.
 | |
|  *
 | |
|  * @param insn  - See consumeByte().
 | |
|  * @param byte  - See consumeByte().
 | |
|  * @return      - See consumeByte().
 | |
|  */
 | |
| static int lookAtByte(struct InternalInstruction* insn, uint8_t* byte) {
 | |
|   return insn->reader(insn->readerArg, byte, insn->readerCursor);
 | |
| }
 | |
| 
 | |
| static void unconsumeByte(struct InternalInstruction* insn) {
 | |
|   insn->readerCursor--;
 | |
| }
 | |
| 
 | |
| #define CONSUME_FUNC(name, type)                                  \
 | |
|   static int name(struct InternalInstruction* insn, type* ptr) {  \
 | |
|     type combined = 0;                                            \
 | |
|     unsigned offset;                                              \
 | |
|     for (offset = 0; offset < sizeof(type); ++offset) {           \
 | |
|       uint8_t byte;                                               \
 | |
|       int ret = insn->reader(insn->readerArg,                     \
 | |
|                              &byte,                               \
 | |
|                              insn->readerCursor + offset);        \
 | |
|       if (ret)                                                    \
 | |
|         return ret;                                               \
 | |
|       combined = combined | ((uint64_t)byte << (offset * 8));     \
 | |
|     }                                                             \
 | |
|     *ptr = combined;                                              \
 | |
|     insn->readerCursor += sizeof(type);                           \
 | |
|     return 0;                                                     \
 | |
|   }
 | |
| 
 | |
| /*
 | |
|  * consume* - Use the reader function provided by the user to consume data
 | |
|  *   values of various sizes from the instruction's memory and advance the
 | |
|  *   cursor appropriately.  These readers perform endian conversion.
 | |
|  *
 | |
|  * @param insn    - See consumeByte().
 | |
|  * @param ptr     - A pointer to a pre-allocated memory of appropriate size to
 | |
|  *                  be populated with the data read.
 | |
|  * @return        - See consumeByte().
 | |
|  */
 | |
| CONSUME_FUNC(consumeInt8, int8_t)
 | |
| CONSUME_FUNC(consumeInt16, int16_t)
 | |
| CONSUME_FUNC(consumeInt32, int32_t)
 | |
| CONSUME_FUNC(consumeUInt16, uint16_t)
 | |
| CONSUME_FUNC(consumeUInt32, uint32_t)
 | |
| CONSUME_FUNC(consumeUInt64, uint64_t)
 | |
| 
 | |
| /*
 | |
|  * dbgprintf - Uses the logging function provided by the user to log a single
 | |
|  *   message, typically without a carriage-return.
 | |
|  *
 | |
|  * @param insn    - The instruction containing the logging function.
 | |
|  * @param format  - See printf().
 | |
|  * @param ...     - See printf().
 | |
|  */
 | |
| static void dbgprintf(struct InternalInstruction* insn,
 | |
|                       const char* format,
 | |
|                       ...) {  
 | |
|   char buffer[256];
 | |
|   va_list ap;
 | |
|   
 | |
|   if (!insn->dlog)
 | |
|     return;
 | |
|     
 | |
|   va_start(ap, format);
 | |
|   (void)vsnprintf(buffer, sizeof(buffer), format, ap);
 | |
|   va_end(ap);
 | |
|   
 | |
|   insn->dlog(insn->dlogArg, buffer);
 | |
|   
 | |
|   return;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * setPrefixPresent - Marks that a particular prefix is present at a particular
 | |
|  *   location.
 | |
|  *
 | |
|  * @param insn      - The instruction to be marked as having the prefix.
 | |
|  * @param prefix    - The prefix that is present.
 | |
|  * @param location  - The location where the prefix is located (in the address
 | |
|  *                    space of the instruction's reader).
 | |
|  */
 | |
| static void setPrefixPresent(struct InternalInstruction* insn,
 | |
|                                     uint8_t prefix,
 | |
|                                     uint64_t location)
 | |
| {
 | |
|   insn->prefixPresent[prefix] = 1;
 | |
|   insn->prefixLocations[prefix] = location;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * isPrefixAtLocation - Queries an instruction to determine whether a prefix is
 | |
|  *   present at a given location.
 | |
|  *
 | |
|  * @param insn      - The instruction to be queried.
 | |
|  * @param prefix    - The prefix.
 | |
|  * @param location  - The location to query.
 | |
|  * @return          - Whether the prefix is at that location.
 | |
|  */
 | |
| static BOOL isPrefixAtLocation(struct InternalInstruction* insn,
 | |
|                                uint8_t prefix,
 | |
|                                uint64_t location)
 | |
| {
 | |
|   if (insn->prefixPresent[prefix] == 1 &&
 | |
|      insn->prefixLocations[prefix] == location)
 | |
|     return TRUE;
 | |
|   else
 | |
|     return FALSE;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * readPrefixes - Consumes all of an instruction's prefix bytes, and marks the
 | |
|  *   instruction as having them.  Also sets the instruction's default operand,
 | |
|  *   address, and other relevant data sizes to report operands correctly.
 | |
|  *
 | |
|  * @param insn  - The instruction whose prefixes are to be read.
 | |
|  * @return      - 0 if the instruction could be read until the end of the prefix
 | |
|  *                bytes, and no prefixes conflicted; nonzero otherwise.
 | |
|  */
 | |
| static int readPrefixes(struct InternalInstruction* insn) {
 | |
|   BOOL isPrefix = TRUE;
 | |
|   BOOL prefixGroups[4] = { FALSE };
 | |
|   uint64_t prefixLocation;
 | |
|   uint8_t byte = 0;
 | |
|   
 | |
|   BOOL hasAdSize = FALSE;
 | |
|   BOOL hasOpSize = FALSE;
 | |
|   
 | |
|   dbgprintf(insn, "readPrefixes()");
 | |
|     
 | |
|   while (isPrefix) {
 | |
|     prefixLocation = insn->readerCursor;
 | |
|     
 | |
|     if (consumeByte(insn, &byte))
 | |
|       return -1;
 | |
| 
 | |
|     /*
 | |
|      * If the first byte is a LOCK prefix break and let it be disassembled
 | |
|      * as a lock "instruction", by creating an <MCInst #xxxx LOCK_PREFIX>.
 | |
|      * FIXME there is currently no way to get the disassembler to print the
 | |
|      * lock prefix if it is not the first byte.
 | |
|      */
 | |
|     if (insn->readerCursor - 1 == insn->startLocation && byte == 0xf0)
 | |
|       break;
 | |
|     
 | |
|     switch (byte) {
 | |
|     case 0xf0:  /* LOCK */
 | |
|     case 0xf2:  /* REPNE/REPNZ */
 | |
|     case 0xf3:  /* REP or REPE/REPZ */
 | |
|       if (prefixGroups[0])
 | |
|         dbgprintf(insn, "Redundant Group 1 prefix");
 | |
|       prefixGroups[0] = TRUE;
 | |
|       setPrefixPresent(insn, byte, prefixLocation);
 | |
|       break;
 | |
|     case 0x2e:  /* CS segment override -OR- Branch not taken */
 | |
|     case 0x36:  /* SS segment override -OR- Branch taken */
 | |
|     case 0x3e:  /* DS segment override */
 | |
|     case 0x26:  /* ES segment override */
 | |
|     case 0x64:  /* FS segment override */
 | |
|     case 0x65:  /* GS segment override */
 | |
|       switch (byte) {
 | |
|       case 0x2e:
 | |
|         insn->segmentOverride = SEG_OVERRIDE_CS;
 | |
|         break;
 | |
|       case 0x36:
 | |
|         insn->segmentOverride = SEG_OVERRIDE_SS;
 | |
|         break;
 | |
|       case 0x3e:
 | |
|         insn->segmentOverride = SEG_OVERRIDE_DS;
 | |
|         break;
 | |
|       case 0x26:
 | |
|         insn->segmentOverride = SEG_OVERRIDE_ES;
 | |
|         break;
 | |
|       case 0x64:
 | |
|         insn->segmentOverride = SEG_OVERRIDE_FS;
 | |
|         break;
 | |
|       case 0x65:
 | |
|         insn->segmentOverride = SEG_OVERRIDE_GS;
 | |
|         break;
 | |
|       default:
 | |
|         debug("Unhandled override");
 | |
|         return -1;
 | |
|       }
 | |
|       if (prefixGroups[1])
 | |
|         dbgprintf(insn, "Redundant Group 2 prefix");
 | |
|       prefixGroups[1] = TRUE;
 | |
|       setPrefixPresent(insn, byte, prefixLocation);
 | |
|       break;
 | |
|     case 0x66:  /* Operand-size override */
 | |
|       if (prefixGroups[2])
 | |
|         dbgprintf(insn, "Redundant Group 3 prefix");
 | |
|       prefixGroups[2] = TRUE;
 | |
|       hasOpSize = TRUE;
 | |
|       setPrefixPresent(insn, byte, prefixLocation);
 | |
|       break;
 | |
|     case 0x67:  /* Address-size override */
 | |
|       if (prefixGroups[3])
 | |
|         dbgprintf(insn, "Redundant Group 4 prefix");
 | |
|       prefixGroups[3] = TRUE;
 | |
|       hasAdSize = TRUE;
 | |
|       setPrefixPresent(insn, byte, prefixLocation);
 | |
|       break;
 | |
|     default:    /* Not a prefix byte */
 | |
|       isPrefix = FALSE;
 | |
|       break;
 | |
|     }
 | |
|     
 | |
|     if (isPrefix)
 | |
|       dbgprintf(insn, "Found prefix 0x%hhx", byte);
 | |
|   }
 | |
|     
 | |
|   insn->vexSize = 0;
 | |
|   
 | |
|   if (byte == 0xc4) {
 | |
|     uint8_t byte1;
 | |
|       
 | |
|     if (lookAtByte(insn, &byte1)) {
 | |
|       dbgprintf(insn, "Couldn't read second byte of VEX");
 | |
|       return -1;
 | |
|     }
 | |
|     
 | |
|     if (insn->mode == MODE_64BIT || (byte1 & 0xc0) == 0xc0) {
 | |
|       insn->vexSize = 3;
 | |
|       insn->necessaryPrefixLocation = insn->readerCursor - 1;
 | |
|     }
 | |
|     else {
 | |
|       unconsumeByte(insn);
 | |
|       insn->necessaryPrefixLocation = insn->readerCursor - 1;
 | |
|     }
 | |
|     
 | |
|     if (insn->vexSize == 3) {
 | |
|       insn->vexPrefix[0] = byte;
 | |
|       consumeByte(insn, &insn->vexPrefix[1]);
 | |
|       consumeByte(insn, &insn->vexPrefix[2]);
 | |
| 
 | |
|       /* We simulate the REX prefix for simplicity's sake */
 | |
|    
 | |
|       if (insn->mode == MODE_64BIT) {
 | |
|         insn->rexPrefix = 0x40 
 | |
|                         | (wFromVEX3of3(insn->vexPrefix[2]) << 3)
 | |
|                         | (rFromVEX2of3(insn->vexPrefix[1]) << 2)
 | |
|                         | (xFromVEX2of3(insn->vexPrefix[1]) << 1)
 | |
|                         | (bFromVEX2of3(insn->vexPrefix[1]) << 0);
 | |
|       }
 | |
|     
 | |
|       switch (ppFromVEX3of3(insn->vexPrefix[2]))
 | |
|       {
 | |
|       default:
 | |
|         break;
 | |
|       case VEX_PREFIX_66:
 | |
|         hasOpSize = TRUE;      
 | |
|         break;
 | |
|       }
 | |
|     
 | |
|       dbgprintf(insn, "Found VEX prefix 0x%hhx 0x%hhx 0x%hhx", insn->vexPrefix[0], insn->vexPrefix[1], insn->vexPrefix[2]);
 | |
|     }
 | |
|   }
 | |
|   else if (byte == 0xc5) {
 | |
|     uint8_t byte1;
 | |
|     
 | |
|     if (lookAtByte(insn, &byte1)) {
 | |
|       dbgprintf(insn, "Couldn't read second byte of VEX");
 | |
|       return -1;
 | |
|     }
 | |
|       
 | |
|     if (insn->mode == MODE_64BIT || (byte1 & 0xc0) == 0xc0) {
 | |
|       insn->vexSize = 2;
 | |
|     }
 | |
|     else {
 | |
|       unconsumeByte(insn);
 | |
|     }
 | |
|     
 | |
|     if (insn->vexSize == 2) {
 | |
|       insn->vexPrefix[0] = byte;
 | |
|       consumeByte(insn, &insn->vexPrefix[1]);
 | |
|         
 | |
|       if (insn->mode == MODE_64BIT) {
 | |
|         insn->rexPrefix = 0x40 
 | |
|                         | (rFromVEX2of2(insn->vexPrefix[1]) << 2);
 | |
|       }
 | |
|         
 | |
|       switch (ppFromVEX2of2(insn->vexPrefix[1]))
 | |
|       {
 | |
|       default:
 | |
|         break;
 | |
|       case VEX_PREFIX_66:
 | |
|         hasOpSize = TRUE;      
 | |
|         break;
 | |
|       }
 | |
|          
 | |
|       dbgprintf(insn, "Found VEX prefix 0x%hhx 0x%hhx", insn->vexPrefix[0], insn->vexPrefix[1]);
 | |
|     }
 | |
|   }
 | |
|   else {
 | |
|     if (insn->mode == MODE_64BIT) {
 | |
|       if ((byte & 0xf0) == 0x40) {
 | |
|         uint8_t opcodeByte;
 | |
|           
 | |
|         if (lookAtByte(insn, &opcodeByte) || ((opcodeByte & 0xf0) == 0x40)) {
 | |
|           dbgprintf(insn, "Redundant REX prefix");
 | |
|           return -1;
 | |
|         }
 | |
|           
 | |
|         insn->rexPrefix = byte;
 | |
|         insn->necessaryPrefixLocation = insn->readerCursor - 2;
 | |
|           
 | |
|         dbgprintf(insn, "Found REX prefix 0x%hhx", byte);
 | |
|       } else {                
 | |
|         unconsumeByte(insn);
 | |
|         insn->necessaryPrefixLocation = insn->readerCursor - 1;
 | |
|       }
 | |
|     } else {
 | |
|       unconsumeByte(insn);
 | |
|       insn->necessaryPrefixLocation = insn->readerCursor - 1;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   if (insn->mode == MODE_16BIT) {
 | |
|     insn->registerSize       = (hasOpSize ? 4 : 2);
 | |
|     insn->addressSize        = (hasAdSize ? 4 : 2);
 | |
|     insn->displacementSize   = (hasAdSize ? 4 : 2);
 | |
|     insn->immediateSize      = (hasOpSize ? 4 : 2);
 | |
|   } else if (insn->mode == MODE_32BIT) {
 | |
|     insn->registerSize       = (hasOpSize ? 2 : 4);
 | |
|     insn->addressSize        = (hasAdSize ? 2 : 4);
 | |
|     insn->displacementSize   = (hasAdSize ? 2 : 4);
 | |
|     insn->immediateSize      = (hasOpSize ? 2 : 4);
 | |
|   } else if (insn->mode == MODE_64BIT) {
 | |
|     if (insn->rexPrefix && wFromREX(insn->rexPrefix)) {
 | |
|       insn->registerSize       = 8;
 | |
|       insn->addressSize        = (hasAdSize ? 4 : 8);
 | |
|       insn->displacementSize   = 4;
 | |
|       insn->immediateSize      = 4;
 | |
|     } else if (insn->rexPrefix) {
 | |
|       insn->registerSize       = (hasOpSize ? 2 : 4);
 | |
|       insn->addressSize        = (hasAdSize ? 4 : 8);
 | |
|       insn->displacementSize   = (hasOpSize ? 2 : 4);
 | |
|       insn->immediateSize      = (hasOpSize ? 2 : 4);
 | |
|     } else {
 | |
|       insn->registerSize       = (hasOpSize ? 2 : 4);
 | |
|       insn->addressSize        = (hasAdSize ? 4 : 8);
 | |
|       insn->displacementSize   = (hasOpSize ? 2 : 4);
 | |
|       insn->immediateSize      = (hasOpSize ? 2 : 4);
 | |
|     }
 | |
|   }
 | |
|   
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * readOpcode - Reads the opcode (excepting the ModR/M byte in the case of
 | |
|  *   extended or escape opcodes).
 | |
|  *
 | |
|  * @param insn  - The instruction whose opcode is to be read.
 | |
|  * @return      - 0 if the opcode could be read successfully; nonzero otherwise.
 | |
|  */
 | |
| static int readOpcode(struct InternalInstruction* insn) {  
 | |
|   /* Determine the length of the primary opcode */
 | |
|   
 | |
|   uint8_t current;
 | |
|   
 | |
|   dbgprintf(insn, "readOpcode()");
 | |
|   
 | |
|   insn->opcodeType = ONEBYTE;
 | |
|     
 | |
|   if (insn->vexSize == 3)
 | |
|   {
 | |
|     switch (mmmmmFromVEX2of3(insn->vexPrefix[1]))
 | |
|     {
 | |
|     default:
 | |
|       dbgprintf(insn, "Unhandled m-mmmm field for instruction (0x%hhx)", mmmmmFromVEX2of3(insn->vexPrefix[1]));
 | |
|       return -1;      
 | |
|     case 0:
 | |
|       break;
 | |
|     case VEX_LOB_0F:
 | |
|       insn->twoByteEscape = 0x0f;
 | |
|       insn->opcodeType = TWOBYTE;
 | |
|       return consumeByte(insn, &insn->opcode);
 | |
|     case VEX_LOB_0F38:
 | |
|       insn->twoByteEscape = 0x0f;
 | |
|       insn->threeByteEscape = 0x38;
 | |
|       insn->opcodeType = THREEBYTE_38;
 | |
|       return consumeByte(insn, &insn->opcode);
 | |
|     case VEX_LOB_0F3A:    
 | |
|       insn->twoByteEscape = 0x0f;
 | |
|       insn->threeByteEscape = 0x3a;
 | |
|       insn->opcodeType = THREEBYTE_3A;
 | |
|       return consumeByte(insn, &insn->opcode);
 | |
|     }
 | |
|   }
 | |
|   else if (insn->vexSize == 2)
 | |
|   {
 | |
|     insn->twoByteEscape = 0x0f;
 | |
|     insn->opcodeType = TWOBYTE;
 | |
|     return consumeByte(insn, &insn->opcode);
 | |
|   }
 | |
|     
 | |
|   if (consumeByte(insn, ¤t))
 | |
|     return -1;
 | |
|   
 | |
|   if (current == 0x0f) {
 | |
|     dbgprintf(insn, "Found a two-byte escape prefix (0x%hhx)", current);
 | |
|     
 | |
|     insn->twoByteEscape = current;
 | |
|     
 | |
|     if (consumeByte(insn, ¤t))
 | |
|       return -1;
 | |
|     
 | |
|     if (current == 0x38) {
 | |
|       dbgprintf(insn, "Found a three-byte escape prefix (0x%hhx)", current);
 | |
|       
 | |
|       insn->threeByteEscape = current;
 | |
|       
 | |
|       if (consumeByte(insn, ¤t))
 | |
|         return -1;
 | |
|       
 | |
|       insn->opcodeType = THREEBYTE_38;
 | |
|     } else if (current == 0x3a) {
 | |
|       dbgprintf(insn, "Found a three-byte escape prefix (0x%hhx)", current);
 | |
|       
 | |
|       insn->threeByteEscape = current;
 | |
|       
 | |
|       if (consumeByte(insn, ¤t))
 | |
|         return -1;
 | |
|       
 | |
|       insn->opcodeType = THREEBYTE_3A;
 | |
|     } else if (current == 0xa6) {
 | |
|       dbgprintf(insn, "Found a three-byte escape prefix (0x%hhx)", current);
 | |
|       
 | |
|       insn->threeByteEscape = current;
 | |
|       
 | |
|       if (consumeByte(insn, ¤t))
 | |
|         return -1;
 | |
|       
 | |
|       insn->opcodeType = THREEBYTE_A6;
 | |
|     } else if (current == 0xa7) {
 | |
|       dbgprintf(insn, "Found a three-byte escape prefix (0x%hhx)", current);
 | |
|       
 | |
|       insn->threeByteEscape = current;
 | |
|       
 | |
|       if (consumeByte(insn, ¤t))
 | |
|         return -1;
 | |
|       
 | |
|       insn->opcodeType = THREEBYTE_A7;
 | |
|     } else {
 | |
|       dbgprintf(insn, "Didn't find a three-byte escape prefix");
 | |
|       
 | |
|       insn->opcodeType = TWOBYTE;
 | |
|     }
 | |
|   }
 | |
|   
 | |
|   /*
 | |
|    * At this point we have consumed the full opcode.
 | |
|    * Anything we consume from here on must be unconsumed.
 | |
|    */
 | |
|   
 | |
|   insn->opcode = current;
 | |
|   
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| static int readModRM(struct InternalInstruction* insn);
 | |
| 
 | |
| /*
 | |
|  * getIDWithAttrMask - Determines the ID of an instruction, consuming
 | |
|  *   the ModR/M byte as appropriate for extended and escape opcodes,
 | |
|  *   and using a supplied attribute mask.
 | |
|  *
 | |
|  * @param instructionID - A pointer whose target is filled in with the ID of the
 | |
|  *                        instruction.
 | |
|  * @param insn          - The instruction whose ID is to be determined.
 | |
|  * @param attrMask      - The attribute mask to search.
 | |
|  * @return              - 0 if the ModR/M could be read when needed or was not
 | |
|  *                        needed; nonzero otherwise.
 | |
|  */
 | |
| static int getIDWithAttrMask(uint16_t* instructionID,
 | |
|                              struct InternalInstruction* insn,
 | |
|                              uint8_t attrMask) {
 | |
|   BOOL hasModRMExtension;
 | |
|   
 | |
|   uint8_t instructionClass;
 | |
| 
 | |
|   instructionClass = contextForAttrs(attrMask);
 | |
|   
 | |
|   hasModRMExtension = modRMRequired(insn->opcodeType,
 | |
|                                     instructionClass,
 | |
|                                     insn->opcode);
 | |
|   
 | |
|   if (hasModRMExtension) {
 | |
|     if (readModRM(insn))
 | |
|       return -1;
 | |
|     
 | |
|     *instructionID = decode(insn->opcodeType,
 | |
|                             instructionClass,
 | |
|                             insn->opcode,
 | |
|                             insn->modRM);
 | |
|   } else {
 | |
|     *instructionID = decode(insn->opcodeType,
 | |
|                             instructionClass,
 | |
|                             insn->opcode,
 | |
|                             0);
 | |
|   }
 | |
|       
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * is16BitEquivalent - Determines whether two instruction names refer to
 | |
|  * equivalent instructions but one is 16-bit whereas the other is not.
 | |
|  *
 | |
|  * @param orig  - The instruction that is not 16-bit
 | |
|  * @param equiv - The instruction that is 16-bit
 | |
|  */
 | |
| static BOOL is16BitEquivalent(const char* orig, const char* equiv) {
 | |
|   off_t i;
 | |
|   
 | |
|   for (i = 0;; i++) {
 | |
|     if (orig[i] == '\0' && equiv[i] == '\0')
 | |
|       return TRUE;
 | |
|     if (orig[i] == '\0' || equiv[i] == '\0')
 | |
|       return FALSE;
 | |
|     if (orig[i] != equiv[i]) {
 | |
|       if ((orig[i] == 'Q' || orig[i] == 'L') && equiv[i] == 'W')
 | |
|         continue;
 | |
|       if ((orig[i] == '6' || orig[i] == '3') && equiv[i] == '1')
 | |
|         continue;
 | |
|       if ((orig[i] == '4' || orig[i] == '2') && equiv[i] == '6')
 | |
|         continue;
 | |
|       return FALSE;
 | |
|     }
 | |
|   }
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * getID - Determines the ID of an instruction, consuming the ModR/M byte as 
 | |
|  *   appropriate for extended and escape opcodes.  Determines the attributes and 
 | |
|  *   context for the instruction before doing so.
 | |
|  *
 | |
|  * @param insn  - The instruction whose ID is to be determined.
 | |
|  * @return      - 0 if the ModR/M could be read when needed or was not needed;
 | |
|  *                nonzero otherwise.
 | |
|  */
 | |
| static int getID(struct InternalInstruction* insn, const void *miiArg) {
 | |
|   uint8_t attrMask;
 | |
|   uint16_t instructionID;
 | |
|   
 | |
|   dbgprintf(insn, "getID()");
 | |
|     
 | |
|   attrMask = ATTR_NONE;
 | |
| 
 | |
|   if (insn->mode == MODE_64BIT)
 | |
|     attrMask |= ATTR_64BIT;
 | |
|     
 | |
|   if (insn->vexSize) {
 | |
|     attrMask |= ATTR_VEX;
 | |
| 
 | |
|     if (insn->vexSize == 3) {
 | |
|       switch (ppFromVEX3of3(insn->vexPrefix[2])) {
 | |
|       case VEX_PREFIX_66:
 | |
|         attrMask |= ATTR_OPSIZE;    
 | |
|         break;
 | |
|       case VEX_PREFIX_F3:
 | |
|         attrMask |= ATTR_XS;
 | |
|         break;
 | |
|       case VEX_PREFIX_F2:
 | |
|         attrMask |= ATTR_XD;
 | |
|         break;
 | |
|       }
 | |
|     
 | |
|       if (lFromVEX3of3(insn->vexPrefix[2]))
 | |
|         attrMask |= ATTR_VEXL;
 | |
|     }
 | |
|     else if (insn->vexSize == 2) {
 | |
|       switch (ppFromVEX2of2(insn->vexPrefix[1])) {
 | |
|       case VEX_PREFIX_66:
 | |
|         attrMask |= ATTR_OPSIZE;    
 | |
|         break;
 | |
|       case VEX_PREFIX_F3:
 | |
|         attrMask |= ATTR_XS;
 | |
|         break;
 | |
|       case VEX_PREFIX_F2:
 | |
|         attrMask |= ATTR_XD;
 | |
|         break;
 | |
|       }
 | |
|     
 | |
|       if (lFromVEX2of2(insn->vexPrefix[1]))
 | |
|         attrMask |= ATTR_VEXL;
 | |
|     }
 | |
|     else {
 | |
|       return -1;
 | |
|     }
 | |
|   }
 | |
|   else {
 | |
|     if (isPrefixAtLocation(insn, 0x66, insn->necessaryPrefixLocation))
 | |
|       attrMask |= ATTR_OPSIZE;
 | |
|     else if (isPrefixAtLocation(insn, 0x67, insn->necessaryPrefixLocation))
 | |
|       attrMask |= ATTR_ADSIZE;
 | |
|     else if (isPrefixAtLocation(insn, 0xf3, insn->necessaryPrefixLocation))
 | |
|       attrMask |= ATTR_XS;
 | |
|     else if (isPrefixAtLocation(insn, 0xf2, insn->necessaryPrefixLocation))
 | |
|       attrMask |= ATTR_XD;
 | |
|   }
 | |
| 
 | |
|   if (insn->rexPrefix & 0x08)
 | |
|     attrMask |= ATTR_REXW;
 | |
| 
 | |
|   if (getIDWithAttrMask(&instructionID, insn, attrMask))
 | |
|     return -1;
 | |
| 
 | |
|   /* The following clauses compensate for limitations of the tables. */
 | |
| 
 | |
|   if ((attrMask & ATTR_VEXL) && (attrMask & ATTR_REXW) &&
 | |
|       !(attrMask & ATTR_OPSIZE)) {
 | |
|     /*
 | |
|      * Some VEX instructions ignore the L-bit, but use the W-bit. Normally L-bit
 | |
|      * has precedence since there are no L-bit with W-bit entries in the tables.
 | |
|      * So if the L-bit isn't significant we should use the W-bit instead.
 | |
|      * We only need to do this if the instruction doesn't specify OpSize since
 | |
|      * there is a VEX_L_W_OPSIZE table.
 | |
|      */
 | |
| 
 | |
|     const struct InstructionSpecifier *spec;
 | |
|     uint16_t instructionIDWithWBit;
 | |
|     const struct InstructionSpecifier *specWithWBit;
 | |
| 
 | |
|     spec = specifierForUID(instructionID);
 | |
| 
 | |
|     if (getIDWithAttrMask(&instructionIDWithWBit,
 | |
|                           insn,
 | |
|                           (attrMask & (~ATTR_VEXL)) | ATTR_REXW)) {
 | |
|       insn->instructionID = instructionID;
 | |
|       insn->spec = spec;
 | |
|       return 0;
 | |
|     }
 | |
| 
 | |
|     specWithWBit = specifierForUID(instructionIDWithWBit);
 | |
| 
 | |
|     if (instructionID != instructionIDWithWBit) {
 | |
|       insn->instructionID = instructionIDWithWBit;
 | |
|       insn->spec = specWithWBit;
 | |
|     } else {
 | |
|       insn->instructionID = instructionID;
 | |
|       insn->spec = spec;
 | |
|     }
 | |
|     return 0;
 | |
|   }
 | |
| 
 | |
|   if (insn->prefixPresent[0x66] && !(attrMask & ATTR_OPSIZE)) {
 | |
|     /*
 | |
|      * The instruction tables make no distinction between instructions that
 | |
|      * allow OpSize anywhere (i.e., 16-bit operations) and that need it in a
 | |
|      * particular spot (i.e., many MMX operations).  In general we're
 | |
|      * conservative, but in the specific case where OpSize is present but not
 | |
|      * in the right place we check if there's a 16-bit operation.
 | |
|      */
 | |
|     
 | |
|     const struct InstructionSpecifier *spec;
 | |
|     uint16_t instructionIDWithOpsize;
 | |
|     const char *specName, *specWithOpSizeName;
 | |
|     
 | |
|     spec = specifierForUID(instructionID);
 | |
|     
 | |
|     if (getIDWithAttrMask(&instructionIDWithOpsize,
 | |
|                           insn,
 | |
|                           attrMask | ATTR_OPSIZE)) {
 | |
|       /* 
 | |
|        * ModRM required with OpSize but not present; give up and return version
 | |
|        * without OpSize set
 | |
|        */
 | |
|       
 | |
|       insn->instructionID = instructionID;
 | |
|       insn->spec = spec;
 | |
|       return 0;
 | |
|     }
 | |
|     
 | |
|     specName = x86DisassemblerGetInstrName(instructionID, miiArg);
 | |
|     specWithOpSizeName =
 | |
|       x86DisassemblerGetInstrName(instructionIDWithOpsize, miiArg);
 | |
| 
 | |
|     if (is16BitEquivalent(specName, specWithOpSizeName)) {
 | |
|       insn->instructionID = instructionIDWithOpsize;
 | |
|       insn->spec = specifierForUID(instructionIDWithOpsize);
 | |
|     } else {
 | |
|       insn->instructionID = instructionID;
 | |
|       insn->spec = spec;
 | |
|     }
 | |
|     return 0;
 | |
|   }
 | |
| 
 | |
|   if (insn->opcodeType == ONEBYTE && insn->opcode == 0x90 &&
 | |
|       insn->rexPrefix & 0x01) {
 | |
|     /*
 | |
|      * NOOP shouldn't decode as NOOP if REX.b is set. Instead
 | |
|      * it should decode as XCHG %r8, %eax.
 | |
|      */
 | |
| 
 | |
|     const struct InstructionSpecifier *spec;
 | |
|     uint16_t instructionIDWithNewOpcode;
 | |
|     const struct InstructionSpecifier *specWithNewOpcode;
 | |
| 
 | |
|     spec = specifierForUID(instructionID);
 | |
|     
 | |
|     /* Borrow opcode from one of the other XCHGar opcodes */
 | |
|     insn->opcode = 0x91;
 | |
|    
 | |
|     if (getIDWithAttrMask(&instructionIDWithNewOpcode,
 | |
|                           insn,
 | |
|                           attrMask)) {
 | |
|       insn->opcode = 0x90;
 | |
| 
 | |
|       insn->instructionID = instructionID;
 | |
|       insn->spec = spec;
 | |
|       return 0;
 | |
|     }
 | |
| 
 | |
|     specWithNewOpcode = specifierForUID(instructionIDWithNewOpcode);
 | |
| 
 | |
|     /* Change back */
 | |
|     insn->opcode = 0x90;
 | |
| 
 | |
|     insn->instructionID = instructionIDWithNewOpcode;
 | |
|     insn->spec = specWithNewOpcode;
 | |
| 
 | |
|     return 0;
 | |
|   }
 | |
|   
 | |
|   insn->instructionID = instructionID;
 | |
|   insn->spec = specifierForUID(insn->instructionID);
 | |
|   
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * readSIB - Consumes the SIB byte to determine addressing information for an
 | |
|  *   instruction.
 | |
|  *
 | |
|  * @param insn  - The instruction whose SIB byte is to be read.
 | |
|  * @return      - 0 if the SIB byte was successfully read; nonzero otherwise.
 | |
|  */
 | |
| static int readSIB(struct InternalInstruction* insn) {
 | |
|   SIBIndex sibIndexBase = 0;
 | |
|   SIBBase sibBaseBase = 0;
 | |
|   uint8_t index, base;
 | |
|   
 | |
|   dbgprintf(insn, "readSIB()");
 | |
|   
 | |
|   if (insn->consumedSIB)
 | |
|     return 0;
 | |
|   
 | |
|   insn->consumedSIB = TRUE;
 | |
|   
 | |
|   switch (insn->addressSize) {
 | |
|   case 2:
 | |
|     dbgprintf(insn, "SIB-based addressing doesn't work in 16-bit mode");
 | |
|     return -1;
 | |
|     break;
 | |
|   case 4:
 | |
|     sibIndexBase = SIB_INDEX_EAX;
 | |
|     sibBaseBase = SIB_BASE_EAX;
 | |
|     break;
 | |
|   case 8:
 | |
|     sibIndexBase = SIB_INDEX_RAX;
 | |
|     sibBaseBase = SIB_BASE_RAX;
 | |
|     break;
 | |
|   }
 | |
| 
 | |
|   if (consumeByte(insn, &insn->sib))
 | |
|     return -1;
 | |
|   
 | |
|   index = indexFromSIB(insn->sib) | (xFromREX(insn->rexPrefix) << 3);
 | |
|   
 | |
|   switch (index) {
 | |
|   case 0x4:
 | |
|     insn->sibIndex = SIB_INDEX_NONE;
 | |
|     break;
 | |
|   default:
 | |
|     insn->sibIndex = (SIBIndex)(sibIndexBase + index);
 | |
|     if (insn->sibIndex == SIB_INDEX_sib ||
 | |
|         insn->sibIndex == SIB_INDEX_sib64)
 | |
|       insn->sibIndex = SIB_INDEX_NONE;
 | |
|     break;
 | |
|   }
 | |
|   
 | |
|   switch (scaleFromSIB(insn->sib)) {
 | |
|   case 0:
 | |
|     insn->sibScale = 1;
 | |
|     break;
 | |
|   case 1:
 | |
|     insn->sibScale = 2;
 | |
|     break;
 | |
|   case 2:
 | |
|     insn->sibScale = 4;
 | |
|     break;
 | |
|   case 3:
 | |
|     insn->sibScale = 8;
 | |
|     break;
 | |
|   }
 | |
|   
 | |
|   base = baseFromSIB(insn->sib) | (bFromREX(insn->rexPrefix) << 3);
 | |
|   
 | |
|   switch (base) {
 | |
|   case 0x5:
 | |
|     switch (modFromModRM(insn->modRM)) {
 | |
|     case 0x0:
 | |
|       insn->eaDisplacement = EA_DISP_32;
 | |
|       insn->sibBase = SIB_BASE_NONE;
 | |
|       break;
 | |
|     case 0x1:
 | |
|       insn->eaDisplacement = EA_DISP_8;
 | |
|       insn->sibBase = (insn->addressSize == 4 ? 
 | |
|                        SIB_BASE_EBP : SIB_BASE_RBP);
 | |
|       break;
 | |
|     case 0x2:
 | |
|       insn->eaDisplacement = EA_DISP_32;
 | |
|       insn->sibBase = (insn->addressSize == 4 ? 
 | |
|                        SIB_BASE_EBP : SIB_BASE_RBP);
 | |
|       break;
 | |
|     case 0x3:
 | |
|       debug("Cannot have Mod = 0b11 and a SIB byte");
 | |
|       return -1;
 | |
|     }
 | |
|     break;
 | |
|   default:
 | |
|     insn->sibBase = (SIBBase)(sibBaseBase + base);
 | |
|     break;
 | |
|   }
 | |
|   
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * readDisplacement - Consumes the displacement of an instruction.
 | |
|  *
 | |
|  * @param insn  - The instruction whose displacement is to be read.
 | |
|  * @return      - 0 if the displacement byte was successfully read; nonzero 
 | |
|  *                otherwise.
 | |
|  */
 | |
| static int readDisplacement(struct InternalInstruction* insn) {  
 | |
|   int8_t d8;
 | |
|   int16_t d16;
 | |
|   int32_t d32;
 | |
|   
 | |
|   dbgprintf(insn, "readDisplacement()");
 | |
|   
 | |
|   if (insn->consumedDisplacement)
 | |
|     return 0;
 | |
|   
 | |
|   insn->consumedDisplacement = TRUE;
 | |
|   insn->displacementOffset = insn->readerCursor - insn->startLocation;
 | |
|   
 | |
|   switch (insn->eaDisplacement) {
 | |
|   case EA_DISP_NONE:
 | |
|     insn->consumedDisplacement = FALSE;
 | |
|     break;
 | |
|   case EA_DISP_8:
 | |
|     if (consumeInt8(insn, &d8))
 | |
|       return -1;
 | |
|     insn->displacement = d8;
 | |
|     break;
 | |
|   case EA_DISP_16:
 | |
|     if (consumeInt16(insn, &d16))
 | |
|       return -1;
 | |
|     insn->displacement = d16;
 | |
|     break;
 | |
|   case EA_DISP_32:
 | |
|     if (consumeInt32(insn, &d32))
 | |
|       return -1;
 | |
|     insn->displacement = d32;
 | |
|     break;
 | |
|   }
 | |
|   
 | |
|   insn->consumedDisplacement = TRUE;
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * readModRM - Consumes all addressing information (ModR/M byte, SIB byte, and
 | |
|  *   displacement) for an instruction and interprets it.
 | |
|  *
 | |
|  * @param insn  - The instruction whose addressing information is to be read.
 | |
|  * @return      - 0 if the information was successfully read; nonzero otherwise.
 | |
|  */
 | |
| static int readModRM(struct InternalInstruction* insn) {  
 | |
|   uint8_t mod, rm, reg;
 | |
|   
 | |
|   dbgprintf(insn, "readModRM()");
 | |
|   
 | |
|   if (insn->consumedModRM)
 | |
|     return 0;
 | |
|   
 | |
|   if (consumeByte(insn, &insn->modRM))
 | |
|     return -1;
 | |
|   insn->consumedModRM = TRUE;
 | |
|   
 | |
|   mod     = modFromModRM(insn->modRM);
 | |
|   rm      = rmFromModRM(insn->modRM);
 | |
|   reg     = regFromModRM(insn->modRM);
 | |
|   
 | |
|   /*
 | |
|    * This goes by insn->registerSize to pick the correct register, which messes
 | |
|    * up if we're using (say) XMM or 8-bit register operands.  That gets fixed in
 | |
|    * fixupReg().
 | |
|    */
 | |
|   switch (insn->registerSize) {
 | |
|   case 2:
 | |
|     insn->regBase = MODRM_REG_AX;
 | |
|     insn->eaRegBase = EA_REG_AX;
 | |
|     break;
 | |
|   case 4:
 | |
|     insn->regBase = MODRM_REG_EAX;
 | |
|     insn->eaRegBase = EA_REG_EAX;
 | |
|     break;
 | |
|   case 8:
 | |
|     insn->regBase = MODRM_REG_RAX;
 | |
|     insn->eaRegBase = EA_REG_RAX;
 | |
|     break;
 | |
|   }
 | |
|   
 | |
|   reg |= rFromREX(insn->rexPrefix) << 3;
 | |
|   rm  |= bFromREX(insn->rexPrefix) << 3;
 | |
|   
 | |
|   insn->reg = (Reg)(insn->regBase + reg);
 | |
|   
 | |
|   switch (insn->addressSize) {
 | |
|   case 2:
 | |
|     insn->eaBaseBase = EA_BASE_BX_SI;
 | |
|      
 | |
|     switch (mod) {
 | |
|     case 0x0:
 | |
|       if (rm == 0x6) {
 | |
|         insn->eaBase = EA_BASE_NONE;
 | |
|         insn->eaDisplacement = EA_DISP_16;
 | |
|         if (readDisplacement(insn))
 | |
|           return -1;
 | |
|       } else {
 | |
|         insn->eaBase = (EABase)(insn->eaBaseBase + rm);
 | |
|         insn->eaDisplacement = EA_DISP_NONE;
 | |
|       }
 | |
|       break;
 | |
|     case 0x1:
 | |
|       insn->eaBase = (EABase)(insn->eaBaseBase + rm);
 | |
|       insn->eaDisplacement = EA_DISP_8;
 | |
|       if (readDisplacement(insn))
 | |
|         return -1;
 | |
|       break;
 | |
|     case 0x2:
 | |
|       insn->eaBase = (EABase)(insn->eaBaseBase + rm);
 | |
|       insn->eaDisplacement = EA_DISP_16;
 | |
|       if (readDisplacement(insn))
 | |
|         return -1;
 | |
|       break;
 | |
|     case 0x3:
 | |
|       insn->eaBase = (EABase)(insn->eaRegBase + rm);
 | |
|       if (readDisplacement(insn))
 | |
|         return -1;
 | |
|       break;
 | |
|     }
 | |
|     break;
 | |
|   case 4:
 | |
|   case 8:
 | |
|     insn->eaBaseBase = (insn->addressSize == 4 ? EA_BASE_EAX : EA_BASE_RAX);
 | |
|     
 | |
|     switch (mod) {
 | |
|     case 0x0:
 | |
|       insn->eaDisplacement = EA_DISP_NONE; /* readSIB may override this */
 | |
|       switch (rm) {
 | |
|       case 0x4:
 | |
|       case 0xc:   /* in case REXW.b is set */
 | |
|         insn->eaBase = (insn->addressSize == 4 ? 
 | |
|                         EA_BASE_sib : EA_BASE_sib64);
 | |
|         readSIB(insn);
 | |
|         if (readDisplacement(insn))
 | |
|           return -1;
 | |
|         break;
 | |
|       case 0x5:
 | |
|         insn->eaBase = EA_BASE_NONE;
 | |
|         insn->eaDisplacement = EA_DISP_32;
 | |
|         if (readDisplacement(insn))
 | |
|           return -1;
 | |
|         break;
 | |
|       default:
 | |
|         insn->eaBase = (EABase)(insn->eaBaseBase + rm);
 | |
|         break;
 | |
|       }
 | |
|       break;
 | |
|     case 0x1:
 | |
|     case 0x2:
 | |
|       insn->eaDisplacement = (mod == 0x1 ? EA_DISP_8 : EA_DISP_32);
 | |
|       switch (rm) {
 | |
|       case 0x4:
 | |
|       case 0xc:   /* in case REXW.b is set */
 | |
|         insn->eaBase = EA_BASE_sib;
 | |
|         readSIB(insn);
 | |
|         if (readDisplacement(insn))
 | |
|           return -1;
 | |
|         break;
 | |
|       default:
 | |
|         insn->eaBase = (EABase)(insn->eaBaseBase + rm);
 | |
|         if (readDisplacement(insn))
 | |
|           return -1;
 | |
|         break;
 | |
|       }
 | |
|       break;
 | |
|     case 0x3:
 | |
|       insn->eaDisplacement = EA_DISP_NONE;
 | |
|       insn->eaBase = (EABase)(insn->eaRegBase + rm);
 | |
|       break;
 | |
|     }
 | |
|     break;
 | |
|   } /* switch (insn->addressSize) */
 | |
|   
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| #define GENERIC_FIXUP_FUNC(name, base, prefix)            \
 | |
|   static uint8_t name(struct InternalInstruction *insn,   \
 | |
|                       OperandType type,                   \
 | |
|                       uint8_t index,                      \
 | |
|                       uint8_t *valid) {                   \
 | |
|     *valid = 1;                                           \
 | |
|     switch (type) {                                       \
 | |
|     default:                                              \
 | |
|       debug("Unhandled register type");                   \
 | |
|       *valid = 0;                                         \
 | |
|       return 0;                                           \
 | |
|     case TYPE_Rv:                                         \
 | |
|       return base + index;                                \
 | |
|     case TYPE_R8:                                         \
 | |
|       if (insn->rexPrefix &&                              \
 | |
|          index >= 4 && index <= 7) {                      \
 | |
|         return prefix##_SPL + (index - 4);                \
 | |
|       } else {                                            \
 | |
|         return prefix##_AL + index;                       \
 | |
|       }                                                   \
 | |
|     case TYPE_R16:                                        \
 | |
|       return prefix##_AX + index;                         \
 | |
|     case TYPE_R32:                                        \
 | |
|       return prefix##_EAX + index;                        \
 | |
|     case TYPE_R64:                                        \
 | |
|       return prefix##_RAX + index;                        \
 | |
|     case TYPE_XMM256:                                     \
 | |
|       return prefix##_YMM0 + index;                       \
 | |
|     case TYPE_XMM128:                                     \
 | |
|     case TYPE_XMM64:                                      \
 | |
|     case TYPE_XMM32:                                      \
 | |
|     case TYPE_XMM:                                        \
 | |
|       return prefix##_XMM0 + index;                       \
 | |
|     case TYPE_MM64:                                       \
 | |
|     case TYPE_MM32:                                       \
 | |
|     case TYPE_MM:                                         \
 | |
|       if (index > 7)                                      \
 | |
|         *valid = 0;                                       \
 | |
|       return prefix##_MM0 + index;                        \
 | |
|     case TYPE_SEGMENTREG:                                 \
 | |
|       if (index > 5)                                      \
 | |
|         *valid = 0;                                       \
 | |
|       return prefix##_ES + index;                         \
 | |
|     case TYPE_DEBUGREG:                                   \
 | |
|       if (index > 7)                                      \
 | |
|         *valid = 0;                                       \
 | |
|       return prefix##_DR0 + index;                        \
 | |
|     case TYPE_CONTROLREG:                                 \
 | |
|       if (index > 8)                                      \
 | |
|         *valid = 0;                                       \
 | |
|       return prefix##_CR0 + index;                        \
 | |
|     }                                                     \
 | |
|   }
 | |
| 
 | |
| /*
 | |
|  * fixup*Value - Consults an operand type to determine the meaning of the
 | |
|  *   reg or R/M field.  If the operand is an XMM operand, for example, an
 | |
|  *   operand would be XMM0 instead of AX, which readModRM() would otherwise
 | |
|  *   misinterpret it as.
 | |
|  *
 | |
|  * @param insn  - The instruction containing the operand.
 | |
|  * @param type  - The operand type.
 | |
|  * @param index - The existing value of the field as reported by readModRM().
 | |
|  * @param valid - The address of a uint8_t.  The target is set to 1 if the
 | |
|  *                field is valid for the register class; 0 if not.
 | |
|  * @return      - The proper value.
 | |
|  */
 | |
| GENERIC_FIXUP_FUNC(fixupRegValue, insn->regBase,    MODRM_REG)
 | |
| GENERIC_FIXUP_FUNC(fixupRMValue,  insn->eaRegBase,  EA_REG)
 | |
| 
 | |
| /*
 | |
|  * fixupReg - Consults an operand specifier to determine which of the
 | |
|  *   fixup*Value functions to use in correcting readModRM()'ss interpretation.
 | |
|  *
 | |
|  * @param insn  - See fixup*Value().
 | |
|  * @param op    - The operand specifier.
 | |
|  * @return      - 0 if fixup was successful; -1 if the register returned was
 | |
|  *                invalid for its class.
 | |
|  */
 | |
| static int fixupReg(struct InternalInstruction *insn, 
 | |
|                     const struct OperandSpecifier *op) {
 | |
|   uint8_t valid;
 | |
|   
 | |
|   dbgprintf(insn, "fixupReg()");
 | |
|   
 | |
|   switch ((OperandEncoding)op->encoding) {
 | |
|   default:
 | |
|     debug("Expected a REG or R/M encoding in fixupReg");
 | |
|     return -1;
 | |
|   case ENCODING_VVVV:
 | |
|     insn->vvvv = (Reg)fixupRegValue(insn,
 | |
|                                     (OperandType)op->type,
 | |
|                                     insn->vvvv,
 | |
|                                     &valid);
 | |
|     if (!valid)
 | |
|       return -1;
 | |
|     break;
 | |
|   case ENCODING_REG:
 | |
|     insn->reg = (Reg)fixupRegValue(insn,
 | |
|                                    (OperandType)op->type,
 | |
|                                    insn->reg - insn->regBase,
 | |
|                                    &valid);
 | |
|     if (!valid)
 | |
|       return -1;
 | |
|     break;
 | |
|   case ENCODING_RM:
 | |
|     if (insn->eaBase >= insn->eaRegBase) {
 | |
|       insn->eaBase = (EABase)fixupRMValue(insn,
 | |
|                                           (OperandType)op->type,
 | |
|                                           insn->eaBase - insn->eaRegBase,
 | |
|                                           &valid);
 | |
|       if (!valid)
 | |
|         return -1;
 | |
|     }
 | |
|     break;
 | |
|   }
 | |
|   
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * readOpcodeModifier - Reads an operand from the opcode field of an 
 | |
|  *   instruction.  Handles AddRegFrm instructions.
 | |
|  *
 | |
|  * @param insn    - The instruction whose opcode field is to be read.
 | |
|  * @param inModRM - Indicates that the opcode field is to be read from the
 | |
|  *                  ModR/M extension; useful for escape opcodes
 | |
|  * @return        - 0 on success; nonzero otherwise.
 | |
|  */
 | |
| static int readOpcodeModifier(struct InternalInstruction* insn) {
 | |
|   dbgprintf(insn, "readOpcodeModifier()");
 | |
|   
 | |
|   if (insn->consumedOpcodeModifier)
 | |
|     return 0;
 | |
|   
 | |
|   insn->consumedOpcodeModifier = TRUE;
 | |
|   
 | |
|   switch (insn->spec->modifierType) {
 | |
|   default:
 | |
|     debug("Unknown modifier type.");
 | |
|     return -1;
 | |
|   case MODIFIER_NONE:
 | |
|     debug("No modifier but an operand expects one.");
 | |
|     return -1;
 | |
|   case MODIFIER_OPCODE:
 | |
|     insn->opcodeModifier = insn->opcode - insn->spec->modifierBase;
 | |
|     return 0;
 | |
|   case MODIFIER_MODRM:
 | |
|     insn->opcodeModifier = insn->modRM - insn->spec->modifierBase;
 | |
|     return 0;
 | |
|   }  
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * readOpcodeRegister - Reads an operand from the opcode field of an 
 | |
|  *   instruction and interprets it appropriately given the operand width.
 | |
|  *   Handles AddRegFrm instructions.
 | |
|  *
 | |
|  * @param insn  - See readOpcodeModifier().
 | |
|  * @param size  - The width (in bytes) of the register being specified.
 | |
|  *                1 means AL and friends, 2 means AX, 4 means EAX, and 8 means
 | |
|  *                RAX.
 | |
|  * @return      - 0 on success; nonzero otherwise.
 | |
|  */
 | |
| static int readOpcodeRegister(struct InternalInstruction* insn, uint8_t size) {
 | |
|   dbgprintf(insn, "readOpcodeRegister()");
 | |
| 
 | |
|   if (readOpcodeModifier(insn))
 | |
|     return -1;
 | |
|   
 | |
|   if (size == 0)
 | |
|     size = insn->registerSize;
 | |
|   
 | |
|   switch (size) {
 | |
|   case 1:
 | |
|     insn->opcodeRegister = (Reg)(MODRM_REG_AL + ((bFromREX(insn->rexPrefix) << 3) 
 | |
|                                                   | insn->opcodeModifier));
 | |
|     if (insn->rexPrefix && 
 | |
|         insn->opcodeRegister >= MODRM_REG_AL + 0x4 &&
 | |
|         insn->opcodeRegister < MODRM_REG_AL + 0x8) {
 | |
|       insn->opcodeRegister = (Reg)(MODRM_REG_SPL
 | |
|                                    + (insn->opcodeRegister - MODRM_REG_AL - 4));
 | |
|     }
 | |
|       
 | |
|     break;
 | |
|   case 2:
 | |
|     insn->opcodeRegister = (Reg)(MODRM_REG_AX
 | |
|                                  + ((bFromREX(insn->rexPrefix) << 3) 
 | |
|                                     | insn->opcodeModifier));
 | |
|     break;
 | |
|   case 4:
 | |
|     insn->opcodeRegister = (Reg)(MODRM_REG_EAX
 | |
|                                  + ((bFromREX(insn->rexPrefix) << 3) 
 | |
|                                     | insn->opcodeModifier));
 | |
|     break;
 | |
|   case 8:
 | |
|     insn->opcodeRegister = (Reg)(MODRM_REG_RAX 
 | |
|                                  + ((bFromREX(insn->rexPrefix) << 3) 
 | |
|                                     | insn->opcodeModifier));
 | |
|     break;
 | |
|   }
 | |
|   
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * readImmediate - Consumes an immediate operand from an instruction, given the
 | |
|  *   desired operand size.
 | |
|  *
 | |
|  * @param insn  - The instruction whose operand is to be read.
 | |
|  * @param size  - The width (in bytes) of the operand.
 | |
|  * @return      - 0 if the immediate was successfully consumed; nonzero
 | |
|  *                otherwise.
 | |
|  */
 | |
| static int readImmediate(struct InternalInstruction* insn, uint8_t size) {
 | |
|   uint8_t imm8;
 | |
|   uint16_t imm16;
 | |
|   uint32_t imm32;
 | |
|   uint64_t imm64;
 | |
|   
 | |
|   dbgprintf(insn, "readImmediate()");
 | |
|   
 | |
|   if (insn->numImmediatesConsumed == 2) {
 | |
|     debug("Already consumed two immediates");
 | |
|     return -1;
 | |
|   }
 | |
|   
 | |
|   if (size == 0)
 | |
|     size = insn->immediateSize;
 | |
|   else
 | |
|     insn->immediateSize = size;
 | |
|   insn->immediateOffset = insn->readerCursor - insn->startLocation;
 | |
|   
 | |
|   switch (size) {
 | |
|   case 1:
 | |
|     if (consumeByte(insn, &imm8))
 | |
|       return -1;
 | |
|     insn->immediates[insn->numImmediatesConsumed] = imm8;
 | |
|     break;
 | |
|   case 2:
 | |
|     if (consumeUInt16(insn, &imm16))
 | |
|       return -1;
 | |
|     insn->immediates[insn->numImmediatesConsumed] = imm16;
 | |
|     break;
 | |
|   case 4:
 | |
|     if (consumeUInt32(insn, &imm32))
 | |
|       return -1;
 | |
|     insn->immediates[insn->numImmediatesConsumed] = imm32;
 | |
|     break;
 | |
|   case 8:
 | |
|     if (consumeUInt64(insn, &imm64))
 | |
|       return -1;
 | |
|     insn->immediates[insn->numImmediatesConsumed] = imm64;
 | |
|     break;
 | |
|   }
 | |
|   
 | |
|   insn->numImmediatesConsumed++;
 | |
|   
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * readVVVV - Consumes vvvv from an instruction if it has a VEX prefix.
 | |
|  *
 | |
|  * @param insn  - The instruction whose operand is to be read.
 | |
|  * @return      - 0 if the vvvv was successfully consumed; nonzero
 | |
|  *                otherwise.
 | |
|  */
 | |
| static int readVVVV(struct InternalInstruction* insn) {
 | |
|   dbgprintf(insn, "readVVVV()");
 | |
|         
 | |
|   if (insn->vexSize == 3)
 | |
|     insn->vvvv = vvvvFromVEX3of3(insn->vexPrefix[2]);
 | |
|   else if (insn->vexSize == 2)
 | |
|     insn->vvvv = vvvvFromVEX2of2(insn->vexPrefix[1]);
 | |
|   else
 | |
|     return -1;
 | |
| 
 | |
|   if (insn->mode != MODE_64BIT)
 | |
|     insn->vvvv &= 0x7;
 | |
| 
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * readOperands - Consults the specifier for an instruction and consumes all
 | |
|  *   operands for that instruction, interpreting them as it goes.
 | |
|  *
 | |
|  * @param insn  - The instruction whose operands are to be read and interpreted.
 | |
|  * @return      - 0 if all operands could be read; nonzero otherwise.
 | |
|  */
 | |
| static int readOperands(struct InternalInstruction* insn) {
 | |
|   int index;
 | |
|   int hasVVVV, needVVVV;
 | |
|   int sawRegImm = 0;
 | |
|   
 | |
|   dbgprintf(insn, "readOperands()");
 | |
| 
 | |
|   /* If non-zero vvvv specified, need to make sure one of the operands
 | |
|      uses it. */
 | |
|   hasVVVV = !readVVVV(insn);
 | |
|   needVVVV = hasVVVV && (insn->vvvv != 0);
 | |
|   
 | |
|   for (index = 0; index < X86_MAX_OPERANDS; ++index) {
 | |
|     switch (x86OperandSets[insn->spec->operands][index].encoding) {
 | |
|     case ENCODING_NONE:
 | |
|       break;
 | |
|     case ENCODING_REG:
 | |
|     case ENCODING_RM:
 | |
|       if (readModRM(insn))
 | |
|         return -1;
 | |
|       if (fixupReg(insn, &x86OperandSets[insn->spec->operands][index]))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_CB:
 | |
|     case ENCODING_CW:
 | |
|     case ENCODING_CD:
 | |
|     case ENCODING_CP:
 | |
|     case ENCODING_CO:
 | |
|     case ENCODING_CT:
 | |
|       dbgprintf(insn, "We currently don't hande code-offset encodings");
 | |
|       return -1;
 | |
|     case ENCODING_IB:
 | |
|       if (sawRegImm) {
 | |
|         /* Saw a register immediate so don't read again and instead split the
 | |
|            previous immediate.  FIXME: This is a hack. */
 | |
|         insn->immediates[insn->numImmediatesConsumed] =
 | |
|           insn->immediates[insn->numImmediatesConsumed - 1] & 0xf;
 | |
|         ++insn->numImmediatesConsumed;
 | |
|         break;
 | |
|       }
 | |
|       if (readImmediate(insn, 1))
 | |
|         return -1;
 | |
|       if (x86OperandSets[insn->spec->operands][index].type == TYPE_IMM3 &&
 | |
|           insn->immediates[insn->numImmediatesConsumed - 1] > 7)
 | |
|         return -1;
 | |
|       if (x86OperandSets[insn->spec->operands][index].type == TYPE_IMM5 &&
 | |
|           insn->immediates[insn->numImmediatesConsumed - 1] > 31)
 | |
|         return -1;
 | |
|       if (x86OperandSets[insn->spec->operands][index].type == TYPE_XMM128 ||
 | |
|           x86OperandSets[insn->spec->operands][index].type == TYPE_XMM256)
 | |
|         sawRegImm = 1;
 | |
|       break;
 | |
|     case ENCODING_IW:
 | |
|       if (readImmediate(insn, 2))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_ID:
 | |
|       if (readImmediate(insn, 4))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_IO:
 | |
|       if (readImmediate(insn, 8))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_Iv:
 | |
|       if (readImmediate(insn, insn->immediateSize))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_Ia:
 | |
|       if (readImmediate(insn, insn->addressSize))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_RB:
 | |
|       if (readOpcodeRegister(insn, 1))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_RW:
 | |
|       if (readOpcodeRegister(insn, 2))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_RD:
 | |
|       if (readOpcodeRegister(insn, 4))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_RO:
 | |
|       if (readOpcodeRegister(insn, 8))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_Rv:
 | |
|       if (readOpcodeRegister(insn, 0))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_I:
 | |
|       if (readOpcodeModifier(insn))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_VVVV:
 | |
|       needVVVV = 0; /* Mark that we have found a VVVV operand. */
 | |
|       if (!hasVVVV)
 | |
|         return -1;
 | |
|       if (fixupReg(insn, &x86OperandSets[insn->spec->operands][index]))
 | |
|         return -1;
 | |
|       break;
 | |
|     case ENCODING_DUP:
 | |
|       break;
 | |
|     default:
 | |
|       dbgprintf(insn, "Encountered an operand with an unknown encoding.");
 | |
|       return -1;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   /* If we didn't find ENCODING_VVVV operand, but non-zero vvvv present, fail */
 | |
|   if (needVVVV) return -1;
 | |
|   
 | |
|   return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * decodeInstruction - Reads and interprets a full instruction provided by the
 | |
|  *   user.
 | |
|  *
 | |
|  * @param insn      - A pointer to the instruction to be populated.  Must be 
 | |
|  *                    pre-allocated.
 | |
|  * @param reader    - The function to be used to read the instruction's bytes.
 | |
|  * @param readerArg - A generic argument to be passed to the reader to store
 | |
|  *                    any internal state.
 | |
|  * @param logger    - If non-NULL, the function to be used to write log messages
 | |
|  *                    and warnings.
 | |
|  * @param loggerArg - A generic argument to be passed to the logger to store
 | |
|  *                    any internal state.
 | |
|  * @param startLoc  - The address (in the reader's address space) of the first
 | |
|  *                    byte in the instruction.
 | |
|  * @param mode      - The mode (real mode, IA-32e, or IA-32e in 64-bit mode) to
 | |
|  *                    decode the instruction in.
 | |
|  * @return          - 0 if the instruction's memory could be read; nonzero if
 | |
|  *                    not.
 | |
|  */
 | |
| int decodeInstruction(struct InternalInstruction* insn,
 | |
|                       byteReader_t reader,
 | |
|                       const void* readerArg,
 | |
|                       dlog_t logger,
 | |
|                       void* loggerArg,
 | |
|                       const void* miiArg,
 | |
|                       uint64_t startLoc,
 | |
|                       DisassemblerMode mode) {
 | |
|   memset(insn, 0, sizeof(struct InternalInstruction));
 | |
|     
 | |
|   insn->reader = reader;
 | |
|   insn->readerArg = readerArg;
 | |
|   insn->dlog = logger;
 | |
|   insn->dlogArg = loggerArg;
 | |
|   insn->startLocation = startLoc;
 | |
|   insn->readerCursor = startLoc;
 | |
|   insn->mode = mode;
 | |
|   insn->numImmediatesConsumed = 0;
 | |
|   
 | |
|   if (readPrefixes(insn)       ||
 | |
|       readOpcode(insn)         ||
 | |
|       getID(insn, miiArg)      ||
 | |
|       insn->instructionID == 0 ||
 | |
|       readOperands(insn))
 | |
|     return -1;
 | |
| 
 | |
|   insn->operands = &x86OperandSets[insn->spec->operands][0];
 | |
|   
 | |
|   insn->length = insn->readerCursor - insn->startLocation;
 | |
|   
 | |
|   dbgprintf(insn, "Read from 0x%llx to 0x%llx: length %zu",
 | |
|             startLoc, insn->readerCursor, insn->length);
 | |
|     
 | |
|   if (insn->length > 15)
 | |
|     dbgprintf(insn, "Instruction exceeds 15-byte limit");
 | |
|   
 | |
|   return 0;
 | |
| }
 |