8296684: Improve String platform support

Reviewed-by: mbalao
Backport-of: 9ae682726873de27cef4d3bd5523713f4ff98266

src/jdk.attach/aix/classes/sun/tools/attach/VirtualMachineImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2023, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2015, 2019 SAP SE. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -143,6 +143,7 @@ public void detach() throws IOException {
      */
     InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOException {
         assert args.length <= 3;                // includes null
+        checkNulls(args);
 
         // did we detach?
         synchronized (this) {

src/jdk.attach/linux/classes/sun/tools/attach/VirtualMachineImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -148,6 +148,7 @@ public void detach() throws IOException {
      */
     InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOException {
         assert args.length <= 3;                // includes null
+        checkNulls(args);
 
         // did we detach?
         synchronized (this) {

src/jdk.attach/macosx/classes/sun/tools/attach/VirtualMachineImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -143,6 +143,7 @@ public void detach() throws IOException {
      */
     InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOException {
         assert args.length <= 3;                // includes null
+        checkNulls(args);
 
         // did we detach?
         synchronized (this) {

src/jdk.attach/share/classes/sun/tools/attach/HotSpotVirtualMachine.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -393,4 +393,14 @@ long attachTimeout() {
         }
         return attachTimeout;
     }
+
+    protected static void checkNulls(Object... args) {
+        for (Object arg : args) {
+            if (arg instanceof String s) {
+                if (s.indexOf(0) >= 0) {
+                    throw new IllegalArgumentException("illegal null character in command");
+                }
+            }
+        }
+    }
 }

src/jdk.attach/windows/classes/sun/tools/attach/VirtualMachineImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -78,6 +78,7 @@ InputStream execute(String cmd, Object ... args)
         throws AgentLoadException, IOException
     {
         assert args.length <= 3;        // includes null
+        checkNulls(args);
 
         // create a pipe using a random name
         Random rnd = new Random();