Oracle America, Inc.

Apple Inc.

Hewlett-packard Development Company, L.p.

Sun Microsystems, Inc.

Oracle America, Inc. Formerly Known As Sun Microsystems, Inc.

Yin Zin Mark Lam

Dean R E Long

Filip J Pizlo

Michael Lawrence Saboff

Antonios Printezis

Bernard Joseph Semeria

Christopher Jordan Plummer

Frank N Yellin

Ivan Krstić

Jacques Fortier

Jiangli Zhou

Saam J Barati

Yusuke Suzuki

Jean-Francois Bastien

Embodiments described herein provide for virtual machine (VM) based exploit mitigation techniques that can be used to harden web content frameworks and JavaScript Engines. Some embodiments described herein are also generally applicable to other system frameworks, libraries, and program code that executes on a processor that is vulnerable to an attack using a security exploit. Program code that implements the techniques described herein can prevent the use of security exploit attacks to bypass security properties within the program code.

Security concepts for web frameworks

In an embodiment, dynamically-generated code may be supported in the system by ensuring that the code either remains executing within a predefined region of memory or exits to one of a set of valid exit addresses. Software embodiments are described in which the dynamically-generated code is scanned prior to permitting execution of the dynamically-generated code to ensure that various criteria are met including exclusion of certain disallowed instructions and control of branch target addresses. Hardware embodiments are described in which the dynamically-generated code is permitted to executed but is monitored to ensure that the execution criteria are met.

Software verification of dynamically generated code

One embodiment of the present invention provides a system that profiles software code to dynamically tune a virtual machine for responsiveness and/or throughput. First, the system profiles software code to track a need for a higher level of responsiveness and/or throughput. The system then gathers statistics for system behavior through the profiling techniques while executing the profiled software code, and uses these statistics to dynamically tune a virtual machine.

Using method-profiling to dynamically tune a virtual machine for responsiveness

A method and computer readable medium are disclosed for predictive caching of web pages for display through a screen of a mobile computing device. A load request is received at a mobile computing device, where the load request includes a current timestamp and an address. The address points to a remote server storing a current copy of the address content. The mobile computing device determines whether there is an existing copy of the address content is pre-cached on the mobile computing device. The mobile computing device determines whether a difference between the current timestamp and a pre-cache timestamp is greater than a heuristic timeliness value. If it is, the mobile computing device pre-caches the current copy of the address content from the remove server at the address on the mobile computing device. The mobile computing device then provides the current copy of the address content for display on its screen.

Heuristic browser predictive pre-caching

One embodiment of the present invention provides a system that uses observed object patterns to dynamically tune a virtual machine for responsiveness and/or throughput. The system first analyzes a memory region containing a set of objects to identify objects in the memory region that indicate the need for responsiveness and/or throughput. The system gathers statistics based on the identified and unidentified objects in the set of objects, and then uses these statistics to dynamically tune a virtual machine.

Using observed object patterns to dynamically tune a virtual machine for responsiveness

One embodiment of the present invention provides a system that uses observed thread activity to dynamically tune a virtual machine for responsiveness and/or throughput. During operation, the system observes the activity of a thread to determine whether the thread needs responsiveness and/or throughput. Next, the system gathers statistics for the thread based on these observations of thread activity, and then uses these statistics to dynamically tune a virtual machine upon which the thread will execute.

Using observed thread activity to dynamically tune a virtual machine for responsiveness

A mechanism is disclosed for implementing fast synchronization of simple synchronized methods in a virtual machine. The mechanism provides for determining, during runtime, whether a set of instructions can be fully executed in lieu of invoking a synchronized method, which requires locking of a particular object. The set of instructions provides equivalent functionality to the synchronized method but with less locking overhead. In response to a determination that the set of instructions can be fully executed, the set of instructions is fully executed to achieve equivalent functionality to the synchronized method in lieu of invoking the synchronized method. In response to a determination that the set of instructions cannot be fully executed, the synchronized method is invoked. With this mechanism, simple synchronized methods can be executed with less locking overhead.

Fast synchronization of simple synchronized methods

A mechanism is disclosed for implementing fast locking in a multi-threaded system. This mechanism enables fast locking to be performed even on an operating system platform that does not allow one thread to assign ownership of a lock on a mutex to another thread. In addition, the mechanism performs locking in a manner that ensures priority correctness and is low-memory safe. In one implementation, the priority correctness is achieved by using operating system mutexes to implement locking, and the low-memory safe aspect is achieved by pre-allocating a memory section to each thread. This pre-allocated memory section ensures that a thread will have sufficient memory to obtain a lock, even when a system is in a low-memory state. With this mechanism, it is possible to implement locking in a safe and efficient manner.

Mechanism for implementing thread synchronization in a priority-correct, low-memory safe manner

A Java virtual machine includes a just in time (JIT) Java compiler. The JIT compiler includes at least one optimizer. Each of the at least one optimizer includes logic for recognizing a pattern in a received Java byte code, logic for optimizing the recognized pattern to produce optimized native code and logic for outputting optimized native code. A method of producing optimized native code is also provided.

Growing community of inventors

Milpitas, CA, United States of America

Yin Zin Mark Lam