--- a/src/os/bsd/vm/os_bsd.cpp	Tue Apr 30 10:53:58 2013 +0200
+++ b/src/os/bsd/vm/os_bsd.cpp	Tue Apr 30 02:28:42 2013 -0700
@@ -2080,9 +2080,10 @@
     flags |= MAP_FIXED;
   }
 
-  // Map uncommitted pages PROT_READ and PROT_WRITE, change access
-  // to PROT_EXEC if executable when we commit the page.
-  addr = (char*)::mmap(requested_addr, bytes, PROT_READ|PROT_WRITE,
+  // Map reserved/uncommitted pages PROT_NONE so we fail early if we
+  // touch an uncommitted page. Otherwise, the read/write might
+  // succeed if we have enough swap space to back the physical page.
+  addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
                        flags, -1, 0);
 
   if (addr != MAP_FAILED) {

--- a/src/os/linux/vm/os_linux.cpp	Tue Apr 30 10:53:58 2013 +0200
+++ b/src/os/linux/vm/os_linux.cpp	Tue Apr 30 02:28:42 2013 -0700
@@ -2906,9 +2906,10 @@
     flags |= MAP_FIXED;
   }
 
-  // Map uncommitted pages PROT_READ and PROT_WRITE, change access
-  // to PROT_EXEC if executable when we commit the page.
-  addr = (char*)::mmap(requested_addr, bytes, PROT_READ|PROT_WRITE,
+  // Map reserved/uncommitted pages PROT_NONE so we fail early if we
+  // touch an uncommitted page. Otherwise, the read/write might
+  // succeed if we have enough swap space to back the physical page.
+  addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
                        flags, -1, 0);
 
   if (addr != MAP_FAILED) {

--- a/src/share/vm/classfile/classFileParser.cpp	Tue Apr 30 10:53:58 2013 +0200
+++ b/src/share/vm/classfile/classFileParser.cpp	Tue Apr 30 02:28:42 2013 -0700
@@ -2027,7 +2027,6 @@
   u2 method_parameters_length = 0;
   u1* method_parameters_data = NULL;
   bool method_parameters_seen = false;
-  bool method_parameters_four_byte_flags;
   bool parsed_code_attribute = false;
   bool parsed_checked_exceptions_attribute = false;
   bool parsed_stackmap_attribute = false;
@@ -2241,26 +2240,14 @@
       }
       method_parameters_seen = true;
       method_parameters_length = cfs->get_u1_fast();
-      // Track the actual size (note: this is written for clarity; a
-      // decent compiler will CSE and constant-fold this into a single
-      // expression)
-      // Use the attribute length to figure out the size of flags
-      if (method_attribute_length == (method_parameters_length * 6u) + 1u) {
-        method_parameters_four_byte_flags = true;
-      } else if (method_attribute_length == (method_parameters_length * 4u) + 1u) {
-        method_parameters_four_byte_flags = false;
-      } else {
+      if (method_attribute_length != (method_parameters_length * 4u) + 1u) {
         classfile_parse_error(
           "Invalid MethodParameters method attribute length %u in class file",
           method_attribute_length, CHECK_(nullHandle));
       }
       method_parameters_data = cfs->get_u1_buffer();
       cfs->skip_u2_fast(method_parameters_length);
-      if (method_parameters_four_byte_flags) {
-        cfs->skip_u4_fast(method_parameters_length);
-      } else {
-        cfs->skip_u2_fast(method_parameters_length);
-      }
+      cfs->skip_u2_fast(method_parameters_length);
       // ignore this attribute if it cannot be reflected
       if (!SystemDictionary::Parameter_klass_loaded())
         method_parameters_length = 0;
@@ -2423,13 +2410,8 @@
     for (int i = 0; i < method_parameters_length; i++) {
       elem[i].name_cp_index = Bytes::get_Java_u2(method_parameters_data);
       method_parameters_data += 2;
-      if (method_parameters_four_byte_flags) {
-        elem[i].flags = Bytes::get_Java_u4(method_parameters_data);
-        method_parameters_data += 4;
-      } else {
-        elem[i].flags = Bytes::get_Java_u2(method_parameters_data);
-        method_parameters_data += 2;
-      }
+      elem[i].flags = Bytes::get_Java_u2(method_parameters_data);
+      method_parameters_data += 2;
     }
   }
 

--- a/src/share/vm/classfile/javaClasses.cpp	Tue Apr 30 10:53:58 2013 +0200
+++ b/src/share/vm/classfile/javaClasses.cpp	Tue Apr 30 02:28:42 2013 -0700
@@ -315,14 +315,18 @@
   return string;
 }
 
-jchar* java_lang_String::as_unicode_string(oop java_string, int& length) {
+jchar* java_lang_String::as_unicode_string(oop java_string, int& length, TRAPS) {
   typeArrayOop value  = java_lang_String::value(java_string);
   int          offset = java_lang_String::offset(java_string);
                length = java_lang_String::length(java_string);
 
-  jchar* result = NEW_RESOURCE_ARRAY(jchar, length);
-  for (int index = 0; index < length; index++) {
-    result[index] = value->char_at(index + offset);
+  jchar* result = NEW_RESOURCE_ARRAY_RETURN_NULL(jchar, length);
+  if (result != NULL) {
+    for (int index = 0; index < length; index++) {
+      result[index] = value->char_at(index + offset);
+    }
+  } else {
+    THROW_MSG_0(vmSymbols::java_lang_OutOfMemoryError(), "could not allocate Unicode string");
   }
   return result;
 }

--- a/src/share/vm/classfile/javaClasses.hpp	Tue Apr 30 10:53:58 2013 +0200
+++ b/src/share/vm/classfile/javaClasses.hpp	Tue Apr 30 02:28:42 2013 -0700
@@ -153,7 +153,7 @@
   static char*  as_utf8_string(oop java_string, char* buf, int buflen);
   static char*  as_utf8_string(oop java_string, int start, int len);
   static char*  as_platform_dependent_str(Handle java_string, TRAPS);
-  static jchar* as_unicode_string(oop java_string, int& length);
+  static jchar* as_unicode_string(oop java_string, int& length, TRAPS);
   // produce an ascii string with all other values quoted using \u####
   static char*  as_quoted_ascii(oop java_string);
 

--- a/src/share/vm/classfile/symbolTable.cpp	Tue Apr 30 10:53:58 2013 +0200
+++ b/src/share/vm/classfile/symbolTable.cpp	Tue Apr 30 02:28:42 2013 -0700
@@ -735,7 +735,7 @@
   ResourceMark rm(THREAD);
   int length;
   Handle h_string (THREAD, string);
-  jchar* chars = java_lang_String::as_unicode_string(string, length);
+  jchar* chars = java_lang_String::as_unicode_string(string, length, CHECK_NULL);
   oop result = intern(h_string, chars, length, CHECK_NULL);
   return result;
 }

--- a/src/share/vm/memory/allocation.hpp	Tue Apr 30 10:53:58 2013 +0200
+++ b/src/share/vm/memory/allocation.hpp	Tue Apr 30 02:28:42 2013 -0700
@@ -539,6 +539,9 @@
 #define NEW_RESOURCE_ARRAY(type, size)\
   (type*) resource_allocate_bytes((size) * sizeof(type))
 
+#define NEW_RESOURCE_ARRAY_RETURN_NULL(type, size)\
+  (type*) resource_allocate_bytes((size) * sizeof(type), AllocFailStrategy::RETURN_NULL)
+
 #define NEW_RESOURCE_ARRAY_IN_THREAD(thread, type, size)\
   (type*) resource_allocate_bytes(thread, (size) * sizeof(type))
 

--- a/src/share/vm/oops/oop.cpp	Tue Apr 30 10:53:58 2013 +0200
+++ b/src/share/vm/oops/oop.cpp	Tue Apr 30 02:28:42 2013 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2013, 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
@@ -103,11 +103,17 @@
 
 // When String table needs to rehash
 unsigned int oopDesc::new_hash(jint seed) {
+  EXCEPTION_MARK;
   ResourceMark rm;
   int length;
-  jchar* chars = java_lang_String::as_unicode_string(this, length);
-  // Use alternate hashing algorithm on the string
-  return AltHashing::murmur3_32(seed, chars, length);
+  jchar* chars = java_lang_String::as_unicode_string(this, length, THREAD);
+  if (chars != NULL) {
+    // Use alternate hashing algorithm on the string
+    return AltHashing::murmur3_32(seed, chars, length);
+  } else {
+    vm_exit_out_of_memory(length, "unable to create Unicode strings for String table rehash");
+    return 0;
+  }
 }
 
 VerifyOopClosure VerifyOopClosure::verify_oop;

--- a/src/share/vm/prims/whitebox.cpp	Tue Apr 30 10:53:58 2013 +0200
+++ b/src/share/vm/prims/whitebox.cpp	Tue Apr 30 02:28:42 2013 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2013, 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
@@ -310,12 +310,8 @@
 WB_ENTRY(jboolean, WB_IsInStringTable(JNIEnv* env, jobject o, jstring javaString))
   ResourceMark rm(THREAD);
   int len;
-  jchar* name = java_lang_String::as_unicode_string(JNIHandles::resolve(javaString), len);
-  oop found_string = StringTable::the_table()->lookup(name, len);
-  if (found_string == NULL) {
-        return false;
-  }
-  return true;
+  jchar* name = java_lang_String::as_unicode_string(JNIHandles::resolve(javaString), len, CHECK_false);
+  return (StringTable::lookup(name, len) != NULL);
 WB_END
 
 
@@ -324,6 +320,11 @@
   Universe::heap()->collect(GCCause::_last_ditch_collection);
 WB_END
 
+
+WB_ENTRY(jlong, WB_ReserveMemory(JNIEnv* env, jobject o, jlong size))
+  return (jlong)os::reserve_memory(size, NULL, 0);
+WB_END
+
 //Some convenience methods to deal with objects from java
 int WhiteBox::offset_for_field(const char* field_name, oop object,
     Symbol* signature_symbol) {
@@ -425,6 +426,8 @@
       CC"(Ljava/lang/reflect/Executable;)V",          (void*)&WB_ClearMethodState},
   {CC"isInStringTable",   CC"(Ljava/lang/String;)Z",  (void*)&WB_IsInStringTable  },
   {CC"fullGC",   CC"()V",                             (void*)&WB_FullGC },
+
+  {CC"reserveMemory", CC"(J)J", (void*)&WB_ReserveMemory },
 };
 
 #undef CC

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/runtime/memory/ReserveMemory.java	Tue Apr 30 02:28:42 2013 -0700
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2013, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @key regression
+ * @bug 8012015
+ * @summary Make sure reserved (but uncommitted) memory is not accessible
+ * @library /testlibrary /testlibrary/whitebox
+ * @build ReserveMemory
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main ReserveMemory
+ */
+
+import com.oracle.java.testlibrary.*;
+
+import java.lang.reflect.Field;
+import sun.hotspot.WhiteBox;
+import sun.misc.Unsafe;
+
+public class ReserveMemory {
+  private static Unsafe getUnsafe() throws Exception {
+    Field f = Unsafe.class.getDeclaredField("theUnsafe");
+    f.setAccessible(true);
+    return (Unsafe)f.get(null);
+  }
+
+  private static boolean isWindows() {
+    return System.getProperty("os.name").toLowerCase().startsWith("win");
+  }
+
+  public static void main(String args[]) throws Exception {
+    if (args.length > 0) {
+      long address = WhiteBox.getWhiteBox().reserveMemory(4096);
+
+      System.out.println("Reserved memory at address: 0x" + Long.toHexString(address));
+      System.out.println("Will now read from the address, expecting a crash!");
+
+      int x = getUnsafe().getInt(address);
+
+      throw new Exception("Read of reserved/uncommitted memory unexpectedly succeeded, expected crash!");
+    }
+
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+          "-Xbootclasspath/a:.",
+          "-XX:+UnlockDiagnosticVMOptions",
+          "-XX:+WhiteBoxAPI",
+          "ReserveMemory",
+          "test");
+
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+    if (isWindows()) {
+      output.shouldContain("EXCEPTION_ACCESS_VIOLATION");
+    } else {
+      output.shouldContain("SIGSEGV");
+    }
+  }
+}

--- a/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java	Tue Apr 30 10:53:58 2013 +0200
+++ b/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java	Tue Apr 30 02:28:42 2013 -0700
@@ -111,6 +111,9 @@
   // Intered strings
   public native boolean isInStringTable(String str);
 
+  // Memory
+  public native long reserveMemory(long size);
+
   // force Full GC
   public native void fullGC();
 }