fuzzer/Fuzzer.java

@@ -18,8 +18,16 @@ public class Fuzzer {
             /* We just print one instruction.
                Hint: you might want to make use of the instruction
                grammar which is effectively encoded in Instruction.java */
+            /*pw.println("MOV R1 0");
+            for(int x=0;x<20000;x++){
+                pw.println("LDR R0 R1 " + x);
+            }
+            pw.println("RET R0");
+            */
+            //pw.println("RET R-1");
+            pw.println("MOV R1 1");
+            pw.println("SUB R0 R0 R1");
             pw.println("RET R0");
-            
         }catch (Exception e){
             e.printStackTrace(System.err);
             System.exit(1);

src/machine-vuln4.c

@@ -58,7 +58,7 @@ static void machine_init(void){
   memory = malloc(sizeof(int32_t)*MEMORY_SIZE);
   regs = malloc(sizeof(int32_t)*NUM_REGS);
   memset(memory,0,sizeof(int32_t)*MEMORY_SIZE);
-  memset(regs,0,sizeof(int32_t)*NUM_REGS);
+  memset(regs,512,sizeof(int32_t)*NUM_REGS);
   count = 0;
 }