University of Washington

Compaq Computer Corporation, Inc.

Google Inc.

Digital Equipment Corporation

Henry M Levy

Steven Gribble

Susan Jane Eggers

Alexander Moshchuk

Tanya Bragin

Alastair Wolman

Joel S Emer

Robert H Halstead, Jr

George Z Chrysos

Tadayoshi Kohno

Brian N Bershad

Theodore H Romer

Geoffrey Michael Voelker

Dennis Chua Lee

John Bradley Chen

Wayne Anthony Wong

Dean Tullsen

Jack Lo

Dean M Tullsen

Rebecca Stamm

Trggve Fossum

Roxana Geambasu

Amin Vahdat

Chandramohan Amyangot Thekkath

David E Culler

William Eugene Morgan

Hassan Mohamed Gamal Hassan Wassel

Anna R Karlin

Richard S Cox

Michael J Feeley

Vivek R Narasayya

Ashutosh Tiwary

Jacob Gorm Hansen

Minlan Yu

Yang Zhou

Aspects of the disclosure are directed to a low-latency, low-overhead fault tolerant remote memory framework, which packs similar-size in-memory objects into individual page-aligned spans and applies erasure coding on these spans. The framework fully utilizes efficient one-sided remote memory accesses (RMAs) to swap spans in and out using minimal network input/outputs (I/Os), with compaction techniques that reduce remote memory fragmentation. The framework can achieve lower tail latency and higher application performance compared to other fault tolerance solutions, at the cost of potentially more memory usage.

Fault tolerant disaggregated memory

A system analyzes content accessed at a network site to determine whether it is malicious. The system employs a tool able to identify spyware that is piggy-backed on executable files (such as software downloads) and is able to detect 'drive-by download' attacks that install software on the victim's computer when a page is rendered by a browser program. The tool uses a virtual machine (VM) to sandbox and analyze potentially malicious content. By installing and running executable files within a clean VM environment, commercial anti-spyware tools can be employed to determine whether a specific executable contains piggy-backed spyware. By visiting a Web page with an unmodified browser inside a clean VM environment, predefined 'triggers,' such as the installation of a new library, or the creation of a new process, can be used to determine whether the page mounts a drive-by download attack.

Detection of spyware threats within virtual machines

Systems and methods for providing an auditing file system for theft-prone devices are disclosed. The auditing file system supports fine-grained file auditing: a user may obtain reliable, explicit evidence that no files have been accessed after a device's loss. A user may also disable future file access after a device's loss, even in the absence of device network connectivity. In one embodiment, files are encrypted locally but the encryption keys are stored remotely, so that an audit server is queried for encryption keys to access protected files. By configuring the audit server to refuse to return a particular file's key, the user can prevent new accesses after the device is lost.

Systems and methods for file access auditing

Detection of spyware threats within virtual machine

A configuration for encapsulating data that is unreadable after a predetermined timeout. To encapsulate data a random data key is generated and split into shares. A threshold number of shares are needed to reconstruct the key. The shares are stored at random locations within one or more networks. Each location is configured to delete the stored data after a predetermined time period. Encapsulated data is created by creating a vanishing data object (VDO) comprising the encrypted data, and data sufficient to locate at least a threshold number of key shares from their stored locations. The VDO becomes inaccessible after enough shares of the data are deleted such that the data key cannot be restored. However, if prior to timeout a sufficient number of data key shares are located and retrieved the data key can be reconstructed. The reconstructed data key is then used to decrypt the original data.

Encapsulation and decapsulation for data disintegration

A Web browsing system using a browser operating system (BOS), which provides a trusted software layer on which Web browsers execute. The BOS runs the client-side component of each Web application (e.g., on-line banking, and Web mail) in its own virtual machine, which provides strong isolation between Web services and the user's local resources. Web publishers can thus limit the scope of their Web applications by specifying the URLs and other resources that their browsers are allowed to access, which limits the harm that can be caused by a compromised browser. Web applications are treated as first-class objects that users explicitly install and manage, giving them explicit knowledge about and control over downloaded content and code. An initial embodiment implemented using Linux and the Xen virtual machine monitor has been shown to prevent or contain about 87% of the vulnerabilities that have been identified in a conventional web browser environment.

Web browser operating system

A multi-threaded processor comprising a pipeline including a number of stages processing instructions belonging to a plurality of threads. A buffer stores instructions from different ones of the threads. Count logic stores count information relating to each of the threads to indicate the number of instructions in each of the corresponding threads that have a particular attribute. A selection logic circuit has an output coupled to the buffer to determine which instruction is to be read from the buffer based on the count information stored by the count logic. The count information may, for example, provide information relating to a likelihood that one or more instructions belonging to each of the threads will be cancelled; relating to a count of unresolved branch instructions; or relating to a count of outstanding data cache misses. In operation, a thread may be selected for execution based on a selected attribute to enhance processing performance.

Pipelined multi-thread processor selecting thread instruction in inter-stage buffer based on count information

A system and a method is described for freeing renaming registers that have been allocated to architectural registers prior to another instruction redefining the architectural register. Renaming registers are used by a processor to dynamically execute instructions out-of-order. The present invention may be employed by any single or multi-threaded processor that executes instructions out-of-order. A mechanism is described for freeing renaming registers that consists of a set of instructions, used by a compiler, to indicate to the processor when it can free the physical (renaming) register that is allocated to a particular architectural register. This mechanism permits the renaming register to be reassigned or reallocated to store another value as soon as the renaming register is no longer needed for allocation to the architectural register. There are at least three ways to enable the processor with an instruction that identifies the renaming register to be freed from allocation: (1) a user may explicitly provide the instruction to the processor that refers to a particular renaming register; (2) an operating system may provide the instruction when a thread is idle that refers to a set of registers associated with the thread; and (3) a compiler may include the instruction with the plurality of instructions presented to the processor. There are at least five embodiments of the instruction provided to the processor for freeing renaming registers allocated to architectural registers: (1) Free Register Bit; (2) Free Register; (3) Free Mask; (4) Free Opcode; and (5) Free Opcode/Mask. The Free Register Bit instruction provides the largest speedup for an out-of-order processor and the Free Register instruction provides the smallest speedup.

Mechanism for freeing registers on processors that perform dynamic out-of-order execution of instructions using renaming registers

A system and method for managing memory in a network. In a computer network in which multiple computers (nodes) are interconnected by a network, the primary memory on one node may be used to store memory data (pages)from other nodes. The transfer of a data page over the network from the memory of a node holding it to the memory of another node requesting that data gives improved performance when compared to the transfer of the same data from disk, either local or remote, to the requesting node. Global information about the disposition of the nodes and their memories in the network is used to determine the nodes in the network that should best be used to hold data pages for other nodes at a particular time. This information is exchanged by the nodes periodically under command of a coordinating node. The system includes distributed data structures that permit one node to locate data pages stored in another node's memory, procedures to determine when global information should be recomputed and redistributed, and procedures to avoid overburdening nodes with remote page traffic.

Using global memory information to manage memory in a computer network

A system and a method is disclosed for analyzing, benchmarking and tuning an object oriented database (OODB) and applications with a trace based technique. Code associated with the application is augmented with a plurality of instructions that define the production of an application execution trace and a database layout trace during execution of the application with a database. A precompiler or manual or automatic techniques are used to augment source code associated with the application. Alternatively, an instrumentor can be employed to augment object code associated with the application. A simulator employs the database layout trace and the application execution trace to simulate the execution of the application with an OODB selected by the user. The simulator may be ported to different OODBs or platforms. The simulator produces results associated with the simulation for input to a data analyzer. The data analyzer includes a user interface that enables a user to modify the simulation and can display the analysis of the simulation in real time. In another preferred embodiment, the present invention is employed with a distributed object oriented system that is implemented on multiple computers communicating by a network.

Trace based method for the analysis, benchmarking and tuning of object

A method and organization for implementing the registers required in a computer system supporting multithreading and dynamic out-of-order execution. Multithreaded computer systems are those in which the processor supports multiple contexts (threads), and either rapid context switching from thread to thread or scheduling of instructions from different threads within a single cycle. An important component of processors for such systems is the register file; the processor needs a large register file or resource to provide the registers used for the threads. One form of the invention maintains a set of private architecturally specified registers, and a set of private renaming register for each different thread. In the other three embodiments, sharing of renaming registers between different threads is permitted, to enable a reduction in the total number of registers required. One of these three embodiments enables any of the architecturally specified registers that are private to a thread but are not in use, to be employed as renaming registers. Another of the embodiments treats all registers as sharable and enables any register from the register file or resource to be used as a renaming register for any thread.

Shared register storage mechanisms for multithreaded computer systems

A technique is provided for selecting a preferred thread from a plurality of threads executing within a simultaneous multithreaded, out-of-order execution computer system, the preferred thread possessing those instructions which, while in flight within the pipeline of the computer system provide, in contrast to those instructions belonging to other threads, a more beneficial performance of the central processing unit of the computer system. To determine the preferred thread, a technique is provided to evaluate attributes of each thread which indicate whether the thread includes a number of instructions which are likely to be cancelled while in flight or whether a thread includes instructions which will remain in the instruction queue for a number of cycles, unable to execute, thus stalling the execution of the thread to which the instruction belongs.

Thread properties attribute vector based thread selection in

A computer software tool used for automatically identifying code portions and data portions of a binary executable software program in which the code portions include machine instructions that are of arbitrary length. Software products are typically distributed as binary, executable files, which comprise a string of binary values. In general, an executable file has no structure or meaning, except as determined by its behavior when dynamically executed, one instruction at a time, by a digital computer. The software tool determines a set of addresses for any known code and data portions. The tool is then used to disassemble machine instructions, beginning at a starting address for each known code portion, to identify the target addresses of other code portions and other data portions. Other sections of the binary executable software program that could be either code or data are then analyzed to identify additionAL code and data portions. As new portions are identified, the steps are repeated, until no further code or data portions are identifiable. The binary executable software program may include a plurality of executable modules. The entry addresses for each executable module and any addresses for code portions and data portions referenced and identified by any debug address, any export address, and any relocation address is added to the set of addresses. The binary executable software program is then executed to dynamically identify other executable modules so that the set of addresses can be further extended.

Discovering code and data in a binary executable program

A method and procedure for modifying modules comprising a binary executable software program in such a way that, despite the transformations performed and the creation of new versions of the modules, the transformed program appears (to that program, including all of its components) as if it is running in the identical environment as the original program. The environment includes environment variables, the name of the program, the names of all of the dynamically loaded library (DLL) files that the program references, the directory in which the program resides, and the current directory at the time the program started execution. When the program has been transformed, e.g., for the purposes of monitoring or measurement, the environment also includes the effective addresses of data and instruction references made by the program. By employing the present invention, a modified software program will have the same behavior as the original unmodified program from which it is derived, even though it and many of its environment characteristics have been changed.

Environment manipulation for executing modified executable and

Growing community of inventors

Seattle, WA, United States of America

Henry M Levy