--- a/test/hotspot/jtreg/vmTestbase/vm/mlvm/indy/func/jvmti/share/IndyRedefineClass.c	Tue Aug 28 17:03:16 2018 +0200
+++ b/test/hotspot/jtreg/vmTestbase/vm/mlvm/indy/func/jvmti/share/IndyRedefineClass.c	Wed Aug 22 09:33:18 2018 -0700
@@ -165,8 +165,14 @@
         char * locStr;
     gIsSingleStepWorking = JNI_TRUE;
     locStr = locationToString(jvmti_env, method, location);
-    NSK_DISPLAY1("Single step event: %s\n", locStr);
-    free(locStr);
+
+    if (locStr == NULL) {
+        NSK_DISPLAY0("Error in Single step event: locationToString failed\n");
+        gIsErrorOccured = JNI_TRUE;
+    } else {
+        NSK_DISPLAY1("Single step event: %s\n", locStr);
+        free(locStr);
+    }
 
     popFrameLogic(jvmti_env, thread);
 }

--- a/test/hotspot/jtreg/vmTestbase/vm/mlvm/indy/func/jvmti/stepBreakPopReturn/stepBreakPopReturn.c	Tue Aug 28 17:03:16 2018 +0200
+++ b/test/hotspot/jtreg/vmTestbase/vm/mlvm/indy/func/jvmti/stepBreakPopReturn/stepBreakPopReturn.c	Wed Aug 22 09:33:18 2018 -0700
@@ -37,6 +37,7 @@
 static jboolean gIsMethodEntryWorking = JNI_FALSE;
 static jboolean gIsSingleStepWorking = JNI_FALSE;
 static jboolean gIsBreakpointWorking = JNI_FALSE;
+static jboolean gErrorHappened = JNI_FALSE;
 
 static jboolean gIsBreakpointSet = JNI_FALSE;
 static jboolean gIsFirstCall = JNI_TRUE;
@@ -63,7 +64,8 @@
     if ( ! gIsDebuggerCompatible )
         NSK_DISPLAY1("Breakpoint event fired? %i\n", gIsBreakpointWorking);
 
-    return gIsMethodEntryWorking && gIsSingleStepWorking && (gIsBreakpointWorking || gIsDebuggerCompatible);
+    return gIsMethodEntryWorking && !gErrorHappened && gIsSingleStepWorking
+        && (gIsBreakpointWorking || gIsDebuggerCompatible);
 }
 
 static void JNICALL
@@ -103,8 +105,14 @@
     gIsSingleStepWorking = JNI_TRUE;
 
     locStr = locationToString(jvmti_env, method, location);
-    NSK_DISPLAY1("Single step event: %s\n", locStr);
-    free(locStr);
+
+    if (locStr == NULL) {
+        NSK_DISPLAY0("Error: Single step event has no location\n");
+        gErrorHappened = JNI_TRUE;
+    } else {
+        NSK_DISPLAY1("Single step event: %s\n", locStr);
+        free(locStr);
+    }
 
     NSK_JVMTI_VERIFY(NSK_CPP_STUB4(SetEventNotificationMode, gJvmtiEnv, JVMTI_DISABLE, JVMTI_EVENT_SINGLE_STEP, NULL));
 
@@ -140,8 +148,13 @@
     gIsBreakpointWorking = JNI_TRUE;
 
     locStr = locationToString(jvmti_env, method, location);
-    NSK_DISPLAY1("Breakpoint event at: %s\n", locStr);
-    free(locStr);
+    if (locStr == NULL) {
+        NSK_DISPLAY0("Error: Breakpoint event has no location\n");
+        gErrorHappened = JNI_TRUE;
+    } else {
+        NSK_DISPLAY1("Breakpoint event at: %s\n", locStr);
+        free(locStr);
+    }
 
     NSK_JVMTI_VERIFY(NSK_CPP_STUB3(ClearBreakpoint, jvmti_env, method, location));
     NSK_JVMTI_VERIFY(NSK_CPP_STUB4(SetEventNotificationMode, gJvmtiEnv, JVMTI_DISABLE, JVMTI_EVENT_BREAKPOINT, NULL));

--- a/test/hotspot/jtreg/vmTestbase/vm/mlvm/share/mlvmJvmtiUtils.c	Tue Aug 28 17:03:16 2018 +0200
+++ b/test/hotspot/jtreg/vmTestbase/vm/mlvm/share/mlvmJvmtiUtils.c	Wed Aug 22 09:33:18 2018 -0700
@@ -76,18 +76,31 @@
 
 char * locationToString(jvmtiEnv * pJvmtiEnv, jmethodID method, jlocation location) {
     struct MethodName * pMN;
-    // gcc 7.3 claims that snprintf below can output between 6 and 531 bytes. Setting buffer size to 600.
-    char r[600];
+    int len;
+    char * result;
+    const char * const format = "%s .%s :" JLONG_FORMAT;
 
     pMN = getMethodName(pJvmtiEnv, method);
     if ( ! pMN )
         return strdup("NONE");
 
-    snprintf(r, sizeof(r), "%s .%s :%lx", pMN->classSig, pMN->methodName, (long) location);
+    len = snprintf(NULL, 0, format, pMN->classSig, pMN->methodName, location) + 1;
+
+    if (len <= 0) {
+        free(pMN);
+        return NULL;
+    }
+
+    result = malloc(len);
+    if (result == NULL) {
+        free(pMN);
+        return NULL;
+    }
+
+    snprintf(result, len, format, pMN->classSig, pMN->methodName, location);
 
     free(pMN);
-
-    return strdup(r);
+    return result;
 }
 
 void * getTLS(jvmtiEnv * pJvmtiEnv, jthread thread, jsize sizeToAllocate) {