encorporate rt_target - unique identifier for instructions we will be looking for

genc.py

@@ -19,6 +19,16 @@ class InstructionType(Enum):
         elif self == InstructionType.EVEX: return 2
 
 class Instruction:
+    RT_TARGETS = {
+        "90"    : 1,
+        "C3"    : 2,
+        "C2 iw" : 3,
+        "CC"    : 4,
+        "CD ib" : 5,
+        "0F 34" : 6,
+        "0F 05" : 7,
+    }
+
     def __init__(self, ins):
         self._opc = ins.find("opc").text
         self.x32m = ins.attrib["x32m"]
@@ -48,6 +58,9 @@ class Instruction:
     def has_opreg(self):
         return False
 
+    def encode_rt_target(self):
+        return Instruction.RT_TARGETS.get(self._opc, 0)
+
     def __str__(self):
         return f"<{self.get_type()}> {self.mnemonic} bytes {self.bytes} rex {self.has_rex()} digit {self.has_digit()} modrm {self.has_modrm()} imm {self.has_imm()} value {self.has_value()} opreg {self.has_opreg()}"
 
@@ -283,7 +296,7 @@ def generate_table(groups):
                     int(i.w)
                 ), end = '')
 
-            print(" .opcode_len = {}, .opcode = {{ {} }}  }},".format(opcode_len, opcode))
+            print(" .rt_target = {}, .opcode_len = {}, .opcode = {{ {} }}  }},".format(i.encode_rt_target(), opcode_len, opcode))
             table_len += 1
     # footer
     print("}};\n\nconst unsigned rtdisasm_table_len = {};".format(table_len))

include/rtdisasm_table.h

@@ -24,6 +24,16 @@
 #define VALUE_O                 4
 #define VALUE_T                 5
 
+// these are target instructions that rtdisasm will look for
+#define RT_TARGET_NO_MEANING    0
+#define RT_TARGET_NOP           1   // 90
+#define RT_TARGET_RET           2   // C3
+#define RT_TARGET_RET_N         3   // C2 iw
+#define RT_TARGET_INT3          4   // CC
+#define RT_TARGET_INT_N         5   // CD ib
+#define RT_TARGET_SYSENTER      6   // 0F 34
+#define RT_TARGET_SYSCALL       7   // 0F 05
+
 #define MAX_OPCODE_LEN          4
 
 typedef struct {
@@ -62,6 +72,8 @@ typedef struct {
         } evex;
     };
 
+    uint16_t rt_target;
+    
     uint16_t opcode_len;
     uint8_t opcode[MAX_OPCODE_LEN];
 } instruction_t;

src/rtdisasm_test_data.s

@@ -3,7 +3,7 @@
 .globl test_1_end
 
 test_1:
-    push %rbp
+    push (%rbp)
 
     nop # target that rtdisasm must reach
 test_1_end: