x86: avoid duplicating registers returned by cs_regs_access(). also a…

…dd *CX registers to regs_read[], regs_write[] for REP* instructions

arch/X86/X86Mapping.c

@@ -2799,6 +2799,28 @@ static bool valid_repe(cs_struct *h, unsigned int opcode)
 	// not found
 	return false;
 }
+
+// add *CX register to regs_read[] & regs_write[]
+static void add_cx(MCInst *MI)
+{
+	if (MI->csh->detail) {
+		x86_reg cx;
+
+		if (MI->csh->mode & CS_MODE_16)
+			cx = X86_REG_CX;
+		else if (MI->csh->mode & CS_MODE_32)
+			cx = X86_REG_ECX;
+		else	// 64-bit
+			cx = X86_REG_RCX;
+
+		MI->flat_insn->detail->regs_read[MI->flat_insn->detail->regs_read_count] = cx;
+		MI->flat_insn->detail->regs_read_count++;
+
+		MI->flat_insn->detail->regs_write[MI->flat_insn->detail->regs_write_count] = cx;
+		MI->flat_insn->detail->regs_write_count++;
+	}
+}
+
 // return true if we patch the mnemonic
 bool X86_lockrep(MCInst *MI, SStream *O)
 {
@@ -2818,6 +2840,7 @@ bool X86_lockrep(MCInst *MI, SStream *O)
 #ifndef CAPSTONE_DIET	// only care about memonic in standard (non-diet) mode
 			if (valid_repne(MI->csh, opcode)) {
 				SStream_concat(O, "repne|");
+				add_cx(MI);
 			} else {
 				// invalid prefix
 				MI->x86_prefix[0] = 0;
@@ -2849,8 +2872,10 @@ bool X86_lockrep(MCInst *MI, SStream *O)
 #ifndef CAPSTONE_DIET	// only care about memonic in standard (non-diet) mode
 			if (valid_rep(MI->csh, opcode)) {
 				SStream_concat(O, "rep|");
+				add_cx(MI);
 			} else if (valid_repe(MI->csh, opcode)) {
 				SStream_concat(O, "repe|");
+				add_cx(MI);
 			} else {
 				// invalid prefix
 				MI->x86_prefix[0] = 0;
@@ -3022,26 +3047,26 @@ void X86_reg_access(const cs_insn *insn,
 		cs_x86_op *op = &(x86->operands[i]);
 		switch((int)op->type) {
 			case X86_OP_REG:
-				if (op->access & CS_AC_READ) {
+				if ((op->access & CS_AC_READ) && !arr_exist(regs_read, read_count, op->reg)) {
 					regs_read[read_count] = op->reg;
 					read_count++;
 				}
-				if (op->access & CS_AC_WRITE) {
+				if ((op->access & CS_AC_WRITE) && !arr_exist(regs_write, write_count, op->reg)) {
 					regs_write[write_count] = op->reg;
 					write_count++;
 				}
 				break;
 			case X86_OP_MEM:
 				// registers appeared in memory references always being read
-				if (op->mem.segment != X86_REG_INVALID) {
+				if ((op->mem.segment != X86_REG_INVALID)) {
 					regs_read[read_count] = op->mem.segment;
 					read_count++;
 				}
-				if (op->mem.base != X86_REG_INVALID) {
+				if ((op->mem.base != X86_REG_INVALID) && !arr_exist(regs_read, read_count, op->mem.base)) {
 					regs_read[read_count] = op->mem.base;
 					read_count++;
 				}
-				if (op->mem.index != X86_REG_INVALID) {
+				if ((op->mem.index != X86_REG_INVALID) && !arr_exist(regs_read, read_count, op->mem.index)) {
 					regs_read[read_count] = op->mem.index;
 					read_count++;
 				}

cs.c

@@ -774,30 +774,6 @@ const char *cs_group_name(csh ud, unsigned int group)
 	return handle->group_name(ud, group);
 }
 
-static bool arr_exist8(unsigned char *arr, unsigned char max, unsigned int id)
-{
-	int i;
-
-	for (i = 0; i < max; i++) {
-		if (arr[i] == id)
-			return true;
-	}
-
-	return false;
-}
-
-static bool arr_exist(uint16_t *arr, unsigned char max, unsigned int id)
-{
-	int i;
-
-	for (i = 0; i < max; i++) {
-		if (arr[i] == id)
-			return true;
-	}
-
-	return false;
-}
-
 CAPSTONE_EXPORT
 bool cs_insn_group(csh ud, const cs_insn *insn, unsigned int group_id)
 {

utils.c

@@ -93,3 +93,28 @@ int cs_snprintf(char *buffer, size_t size, const char *fmt, ...)
 
 	return ret;
 }
+
+bool arr_exist8(unsigned char *arr, unsigned char max, unsigned int id)
+{
+	int i;
+
+	for (i = 0; i < max; i++) {
+		if (arr[i] == id)
+			return true;
+	}
+
+	return false;
+}
+
+bool arr_exist(uint16_t *arr, unsigned char max, unsigned int id)
+{
+	int i;
+
+	for (i = 0; i < max; i++) {
+		if (arr[i] == id)
+			return true;
+	}
+
+	return false;
+}
+

utils.h

@@ -54,5 +54,10 @@ int cs_snprintf(char *buffer, size_t size, const char *fmt, ...);
 
 #define CS_AC_IGNORE (1 << 7)
 
+// check if an id is existent in an array
+bool arr_exist8(unsigned char *arr, unsigned char max, unsigned int id);
+
+bool arr_exist(uint16_t *arr, unsigned char max, unsigned int id);
+
 #endif