Method and system for executing applications using native code modules

Some embodiments provide a system that executes a web application. During operation, the system loads the web application in a web browser and loads a native code module associated with the web application into a secure runtime environment. Next, the system provides input data associated with the web application to the native code module and processes the input data using the native code module to obtain output data. Finally, the system provides the output data to the web application for use by the web application.

BACKGROUND

The present embodiments relate to techniques for executing applications on computer systems. More specifically, the present embodiments relate to a method and system for executing web applications using native code modules.

2. Related Art

Computer systems may include a number of native applications that require significant processing resources to execute. Such applications may perform tasks such as image processing, audio and video decoding and mixing, mathematical modeling, and/or simulation. To run efficiently, these applications are often written in a combination of general purpose programming languages such as C or C++ and low-level languages such as assembly language. Consequently, the applications may be restricted to specific platforms, involve a lengthy installation process, and may pose a security risk to the computer systems on which the applications are installed.

On the other hand, web applications, which have become more prevalent in recent years, are typically written in scripting languages that are more secure and require no installation. However, web applications may lack the performance capabilities of native applications. In particular, a web application may run one or two orders of magnitude slower or more than a native application. As a result, web applications are currently unable to implement computationally intensive features that are available in native applications.

SUMMARY

Some embodiments provide a system that executes a web application. During operation, the system loads the web application in a web browser and loads a native code module associated with the web application into a secure runtime environment. Next, the system provides input data associated with the web application to the native code module and processes the input data using the native code module to obtain output data. Finally, the system provides the output data to the web application for use by the web application.

In some embodiments, the system also validates the native code module prior to loading the native code module into the secure runtime environment.

In some embodiments, the output data is provided to a trusted plugin associated with the web browser for use by the trusted plugin.

In some embodiments, the output data is used by the trusted plugin to render graphics for the web application.

In some embodiments, the native code module provides at least one of simulation, signal processing, artificial intelligence, modeling, and analysis for the web application.

In some embodiments, the secure runtime environment is implemented by a plugin associated with the web browser.

In some embodiments, the web application and the native code module are platform independent.

In some embodiments, the input data is provided to the native code module using a first inter-module communication (IMC) buffer, and the output data is provided to the web application using a second IMC buffer.

In some embodiments, processing the input data involves performing a series of mathematical calculations using the input data.

DETAILED DESCRIPTION

Embodiments of the system provide a method and system for executing a web application. The web application may be loaded in a web browser and executed on a computing system such as a personal computer (PC), a mobile phone, a personal digital assistant (PDA), a graphing calculator, a portable media player, a global positioning system (GPS) receiver, and/or another electronic computing device. The web application may be obtained by the computing system from a server using a network connection with the server. For example, the web application may be downloaded over the Internet from a website.

More specifically, embodiments of the technique provide a method and system for executing the web application using a native code module. The native code module may contain native code that is executed within a secure runtime environment. In addition, the native code module may be used to process data for the web application to provide functionality associated with computationally intensive tasks such as simulation, signal processing, artificial intelligence, and/or modeling. As a result, embodiments of the system may provide a framework for combining the portability and security of web applications with the native performance of binary code.

FIG. 1shows a schematic of a system. The system includes a computing system102and a set of servers (e.g., server1104, server x106). Computing system102includes a web application116running within a web browser110and a plugin108. Each of these components is described in further detail below.

Computing system102may correspond to an electronic device that provides one or more services or functions to a user. For example, computing system102may operate as a mobile phone, personal computer (PC), global positioning system (GPS) receiver, portable media player, personal digital assistant (PDA), and/or graphing calculator. In addition, computing system102may include an operating system (not shown) that coordinates the use of hardware and software resources on computing system102, as well as one or more applications (e.g., web browser110, web application116) that perform specialized tasks for the user. For example, computing system102may include applications such as an email client, address book, document editor, web browser110, and/or media player. To perform tasks for the user, applications may obtain the use of hardware resources (e.g., processor, memory, I/O components, wireless transmitter, etc.) on computing system102from the operating system, as well as interact with the user through a hardware and/or software framework provided by the operating system, as described below.

Those skilled in the art will appreciate that computing system102may include functionality to execute both native applications and non-native applications. In other words, computing system102may include native applications, such as web browser110, that are locally installed on computing system102and specific to the operating system and/or one or more hardware devices on computing system102. Such applications may be compiled into native (e.g., machine) code that executes directly on one or more central processing units (CPUs) of computing system102. Code execution in the applications may further be optimized by writing the applications in a combination of general-purpose programming languages (e.g., C, C++, etc.) and assembly language, as well as utilizing libraries that provide hardware acceleration (e.g., graphics hardware acceleration) to the applications. However, the installation of native applications may compromise computing system102and private data stored on computing system102.

Computing system102may also include functionality to execute platform independent, non-native applications. In particular, computing system102may obtain web application116from one or more servers (e.g., server1104, server x106) using a network connection with the server(s) and load web application116in web browser110. For example, web application116may be downloaded from an application server over the Internet by web browser110.

Once loaded, web application116may provide features and user interactivity comparable to that of native applications on computing system102. For example, web application116may function as an email client, document editor, media player, computer-aided design (CAD) system, and/or computer game. Web application116may also include dynamic user interface elements such as menus, buttons, windows, sub-windows, icons, animations, and/or other graphical objects that emulate analogous user interface elements in native applications. In other words, web application116may correspond to a rich Internet application (RIA).

Furthermore, web application116may execute on computing system102regardless of the type of platform (e.g., operating system, drivers, etc.) associated with computing system102. Though platform independent applications such as web application116may be more portable and secure than native applications, such cross-platform applications may lack certain performance capabilities of native applications.

More specifically, non-native applications such as web application116may be written using scripting languages that are interpreted rather than compiled, such as Javascript (Javascript™ is a registered trademark of Sun Microsystems, Inc.). The interpretive nature of web application116and/or other non-native applications may result in significantly slower execution times for the non-native applications than those of compiled native applications. Non-native applications may also be unable to utilize low-level libraries and/or application programming interfaces (API) that are available for use by native applications. Consequently, non-native applications may provide limited functionality in certain tasks.

In particular, web application116may be unable to provide computationally intensive features that are available in native applications. These features may include, but are not limited to:Simulation: computational fluid dynamics (CFD), rigid body dynamics, collision detection, molecular dynamics, three-dimensional (3D) animation, etc.Signal Processing: audio encoding and decoding, video encoding and decoding, image processing, speech signal processing, etc.Artificial Intelligence (AI): data mining, machine learning, game AIs, pattern recognition, etc.Modeling: financial modeling, mathematical modeling, scientific modeling, 3D modeling, etc.Analysis: numerical analysis, financial analysis, engineering analysis, cryptanalysis, statistical data analysis, etc.
In a broad sense, web application116may be unable to efficiently implement features that require the execution of complex mathematical operations, such as floating point operations. For example, web application116may execute too slowly to perform fast Fourier transforms (FFTs), Monte Carlo methods, matrix operations, conjugate gradient methods, and/or regression techniques on input data of a substantial size.

To provide computationally intensive features to the user, a native code module118associated with web application116may be used to execute computationally intensive code on behalf of web application116. Like web application116, native code module118may be obtained from one or more servers (e.g., server1104, server x106) by web browser110. For example, web application116may provide a hyperlink to native code module118on the Internet. Web browser110may then download native code module118from the Uniform Resource Locator (URL) specified in the hyperlink. Alternatively, native code module118may be specified by the user or by an external source, such as another web application and/or a native application.

More specifically, native code module118may correspond to a software module containing native code that runs directly on hardware provided by computing system102, such as a CPU. As a result, native code module118may be used to perform tasks that require substantial access to CPU resources on computing system102. In particular, native code module118may provide one or more of the computationally intensive features listed above to a user of web application116by processing input data associated with web application116. The input data may be processed by performing a series of mathematical calculations using the input data, such as the mathematical operations described above.

Output data obtained from the processed input data may be provided to web application116for use by web application116. For example, the output data may be provided to the user by web application116or used by web application116to perform additional tasks for the user. The output data may also be provided as input data to other components associated with web application116, such as a native application, a trusted plugin, and/or one or more servers (e.g., server1104, server x106).

For example, web application116may provide audio or video encoding and/or decoding capabilities to the user of computing system102. First, the user may specify an audio or video file to decode and/or an audio or video stream to encode. Next, web application116may obtain a native code module (e.g., native code module118) containing a codec for the file or stream from a server (e.g., server1104, server x106). The native code module may then execute on a CPU of computing system102to provide the codec's encoding and/or decoding capabilities to the user.

Similarly, web application116and native code module118may be used by computing system102to perform computationally intensive operations for a distributed computing cluster. More specifically, native code module118may be obtained by web application116and executed by plugin108to create a node in the distributed computing cluster on computing system102. The computationally intensive operations may be performed by native code module118during periods of CPU underutilization on computing system102. Output from native code module118may be sent to a server (e.g., server1104, server x106) to aid in the analysis of complex problems such as protein folding, unsolved mathematics problems, detection of gravitational waves, and/or stock forecasting.

In one or more embodiments, plugin108includes a variety of mechanisms to ensure the safe execution of native code module118. In particular, native code module118may be validated by a validator112provided by plugin108prior to execution. Native code module validation is described in a co-pending non-provisional application by inventors J. Bradley Chen, Matthew T. Harren, Matthew Papakipos, David C. Sehr, and Bennet S. Yee, and filed on the same day as the instant application entitled, “Method for Validating an Untrusted Native Code Module,” having Ser. No. 12/117,634and filing date 8 May 2008, which is incorporated herein by reference.

Once native code module118is validated, native code module118may be loaded into a secure runtime environment114provided by plugin108. Native code execution in a secure runtime environment is described in a co-pending non-provisional application by inventors J. Bradley Chen, Matthew T. Harren, Matthew Papakipos, David C. Sehr, Bennet S. Yee, and Gregory Dardyk and filed on the same day as the instant application, entitled, “Method for Safely Executing an Untrusted Native Code Module on a Computing Device,” having Ser. No. 12/117,650, and filing date 8 May 2008, which is incorporated herein by reference.

While isolating native code modules from all other software and hardware components preserves security, software modules typically do not execute in isolation, and need to communicate results to a client application and/or access system resources. Embodiments of the present invention enable limited communication between the native code module and other system components using a secure runtime environment.

In one embodiment of the present invention, the secure runtime environment:provides the ability to load and launch native code modules;provides an execution environment for native client modules that includes communications, threads, memory management, and debugging support;moderates access to system resources using a simple access policy that ensures that native code modules do not violate system protection and privacy constraints;supports multiple native code modules isolated from each other; andcan be implemented in a small amount of code that can be both easily audited as well as ported to multiple operating systems that run on the same hardware architecture.

The secure runtime environment moderates both which resources can be accessed (and communicated with) by the native code module, as well as how such resources are accessed, thereby ensuring that the native code module relies entirely on the secure runtime environment to access system services and cannot perform sensitive operations without explicit mediation. For instance, a native code module cannot read or change file system state, initiate network (or inter module and/or inter-process) communications, or launch computations outside of an isolated “sandbox,” and instead must rely on the secure runtime environment to perform such interactions (if allowed) on its behalf.

One embodiment of the present invention provides a system that safely executes a native code module on a computing device. During operation, the system receives the native code module, which is comprised of untrusted native program code expressed using native instructions in the instruction set architecture associated with the computing device. The system then loads the native code module into a secure runtime environment, and proceeds to execute a set of instructions from the native code module in the secure runtime environment. The secure runtime environment enforces code integrity, control-flow integrity, and data integrity for the native code module. Furthermore, the secure runtime environment moderates which resources can be accessed by the native code module on the computing device and/or how these resources can be accessed. By executing the native code module in the secure runtime environment, the system facilitates achieving native code performance for untrusted program code without a significant risk of unwanted side effects.

In some embodiments, the system enforces data integrity by using sandboxing techniques that manage and/or limit the memory segments that the native code module can access, thereby ensuring that the untrusted program code in the native code module cannot perform unauthorized data reads or writes. In some embodiments, these techniques leverage hardware support for segmented memory to enforce data integrity.

In one embodiment of the present invention, creating a system-compliant native code module involves following a set of restrictions and/or policies that preserve the integrity and security of code, control flow, and data. Preserving code integrity involves ensuring that only “safe” instructions can be executed by the native code module, and that no unsafe instructions can be inserted at runtime via dynamic code generation or self-modifying code. Restricting the instruction set which is available to the native code module also can help to make decoding the native code module (during validation) more reliable. Preserving control flow integrity involves ensuring that control flow instructions in the native code module cannot violate security by calling instructions outside of the native code module. Preserving data integrity involves ensuring that a native code module cannot perform “wild reads” or “wild writes” (e.g., reads or writes outside of a specified data region associated with the native code module).

In one embodiment of the present invention, the validator helps to achieve code, control-flow, and data integrity for an x86 native code module in part by ensuring that a set of “unsafe” instructions from the x86 ISA (instruction set architecture) are not included in a native code module. For instance, the validator may disallow the use of the following instructions and/or features in a native code module:the syscall (system call) and int (interrupt) instructions, which attempt to directly invoke the operating system;all instructions that modify x86 segment state (including LDS, far calls, etc.), because these instructions interfere with the memory segments that are used to enforce data integrity (see the segmented memory description below);the rdtsc (read time stamp counter) and rdmsr (read from model specific register) instructions, as well as other hardware performance instructions and/or features which may be used by a native code module to mount side-channel attacks (e.g., by covertly leaking sensitive information);various complex addressing modes that complicate the verification of control flow integrity;the ret (return) instruction, which determines a return address from a stack location, and is replaced with a sequence of instructions that use a register-specified destination instead (and hence is not vulnerable to a race condition that allows the stack location to be used as a destination by a first thread to be overwritten maliciously (or erroneously) by a second thread just prior to the execution of the return instruction); andsome aspects of exception and signal functionality—for instance, while the system may support C++ exceptions (as defined in the C++ language specification), the system may not support hardware exceptions (such as divide-by-zero or invalid memory reference exceptions) due to operating system limitations, and may terminate execution of an untrusted native code module when faced with such a hardware exception.

Furthermore, to provide effective code discovery and control integrity, the system also restricts a set of control transfer instructions. Specifically, unmodified indirect control flow instructions that can transfer execution to arbitrary locations in memory need to be modified to guarantee that all indirect control flow targets are in memory regions that are valid for the native code module. One embodiment of the present invention limits indirect control flow instructions by: (1) not allowing return, far call, and far jump instructions, (2) ensuring that call and jump (imp) instructions only use relative addressing and are encoded in a sequence of instructions such that the control flow remains within the native code module; (3) ensuring that register indirect call and jump instructions are encoded in a sequence of instructions such that the control flow remains within the native code module and targets valid instruction addresses within the module; and (4) not allowing other indirect calls and jumps.

Furthermore, because native code module118may include binary code that runs directly on hardware, native code module118may be platform independent with respect to the operating system of computing system102, web browser110, and/or other software components on computing system102. As described in the above-referenced applications, plugin108and/or native code module118may also include mechanisms for executing on a variety of instruction set architectures, including the use of “fat binaries” and binary translators.

FIG. 2shows the use of inter-module communication (IMC) buffers by a native code module. In particular,FIG. 2shows the flow of data through native code module118. As shown inFIG. 2, input data208is obtained by native code module118from a first inter-module communication (IMC) buffer204. As described above, input data208may be specified by web application116, a user, and/or a native application. Input data208may also be obtained from a variety of sources for placement in IMC buffer204, including a host on a network, a disk, an input device (e.g., camera, microphone, etc.), and/or a hardware device (e.g., sound card, video card, etc.).

Native code module118may process input data208to obtain output data210, which is placed into a second IMC buffer206. More specifically, native code module118may obtain output data210by performing a series of mathematical calculations using input data208. For example, native code module202may perform a series of matrix operations, mathematical transforms and/or inverse transforms, and/or other floating point operations using input data208. Output data210may then be obtained from IMC buffer206for use by web application116and/or a trusted plugin202associated with web application116. In particular, web application116and/or trusted plugin202may use output data210to perform additional tasks for a user of web application116or an entity associated with web application116. For example, output data210may be stored in a file that is provided to the user, plotted in a chart or graph, uploaded to a database for a distributed computing cluster, and/or used to modify the execution of other applications. Output data210may also be used to animate a 3D graphics model, as discussed below with respect toFIG. 3.

In one or more embodiments, IMC buffers204-206correspond to shared memory buffers that are used to facilitate data-intensive collaboration between native code module118and external components such as web application116and/or trusted plugin202. Furthermore, sharing of data via IMC buffers204-204may be managed by an IMC runtime, as described in the above-referenced applications.

FIG. 3shows a system for executing a web-based 3D application302. 3D application302may correspond to a web application that executes in a web browser300. In addition, 3D application302may provide 3D graphics rendering and animation capabilities to a user of 3D application. For example, 3D application302may be a 3D computer game, CAD system, and/or a scientific modeling and/or simulation application. Furthermore, 3D application302may be written in a web-based scripting language such as Javascript. As a result, 3D application302may be unable to meet the demands of real-time 3D graphics rendering and animation. Instead, 3D application302may offload graphics rendering to a graphics plugin306and animation to a plugin304.

As shown inFIG. 3, plugin304includes a physics engine310that executes on a CPU318. In one or more embodiments, physics engine310corresponds to a native code module that is executed within a secure runtime environment provided by plugin304. Physics engine310may be provided by 3D application302(e.g., downloaded over the Internet) and validated prior to execution in plugin304. Moreover, physics engine310may include native code that executes directly on CPU318within the constraints set by the secure runtime environment. The execution of physics engine310on CPU318may thus provide 3D application302with real-time animation of objects within 3D application302.

Similarly, graphics plugin304includes a rendering engine312that communicates with a graphics-processing unit (GPU)320. In one or more embodiments, graphics plugin304corresponds to a trusted plugin, such as trusted plugin202ofFIG. 2. In other words, graphics plugin306may be downloaded from a trusted source by web browser300and installed by web browser300to render graphics for 3D application302. Furthermore, rendering engine312may provide graphics hardware acceleration by performing calculations related to graphics rendering using GPU320. Graphics plugin306and rendering engine312are described in a co-pending non-provisional application by inventors Vangelis Kokkevis, Matthew Papakipos, and Robin Green and filed on the same day as the instant application entitled, “WEB-BASED GRAPHICS RENDERING SYSTEM,” having Ser. No. 12/174,586, and filing date filing date Jul. 16, 2008.

In one or more embodiments, 3D application302coordinates the joint execution of physics engine310and rendering engine312. More specifically, 3D application302may make method calls to both plugin304and graphics plugin306for loading a graphics model into rendering engine312and a corresponding physics model into physics engine310. 3D application302may also facilitate the passing of data between plugin304and graphics plugin306using shared memory308, as described below. On the other hand, plugin304and graphics plugin306may interface directly with one another to synchronize the animation and rendering of the graphics model.

In particular, 3D application302may provide an input file that describes a graphics model to graphics plugin306. Alternatively, 3D application302may make a set of method calls that describe the graphics model to graphics plugin306. The graphics model may then be loaded into the internal memory of graphics plugin306. Next, 3D application302may request the allocation of one or more IMC buffers314-316in a region of shared memory308by an IMC runtime provided by plugin304and/or graphics plugin306. Graphics plugin306may then load data relevant to physics simulation into IMC buffers314-316. For example, graphics plugin306may copy vertex positions, normals, triangle indices, and/or transformation matrices into IMC buffers314-316.

To animate the graphics model, physics engine310may read from IMC buffers314-316to create a physics model corresponding to the graphics model in graphics plugin306. Additional information related to the physics model, such as parameters, may be obtained from 3D application302by plugin304. Next, physics engine310may perform a series of physics simulation calculations that update the physics model. For example, physics engine310may calculate vertex positions and velocities based on a set of forces acting on objects in the physics model. Plugin304may then update IMC buffers314-316with new vertex positions, velocities, and/or other data. Finally, the new data is read from IMC buffers314-316by graphics plugin306and used to update the graphics model. Rendering engine312may then pass the updated graphics model to GPU320for rendering.

Graphics rendering and animation may continue to be provided by rendering engine312and physics engine310during execution of 3D application302. For example, physics engine310may continue to update the graphics model as long as forces are felt by objects in the graphics model. Additional objects and/or forces may also be introduced into the graphics model and/or physics model by 3D application302. Similarly, rendering engine312may render the graphics model at a frame rate specified by 3D application302and/or supported by GPU320. As a result, physics engine310and rendering engine312may run at different frequencies. For example, physics engine310may run four times faster than rendering engine312. As a result, the graphics model may be rendered once by rendering engine312for every four updates to the graphics model made by physics engine310.

FIG. 4shows a flowchart illustrating the process of executing a web application. In one or more embodiments, one or more of the steps may be omitted, repeated, and/or performed in a different order. Accordingly, the specific arrangement of steps shown inFIG. 4should not be construed as limiting the scope of the technique.

Initially, a web application is loaded into a web browser (operation402). The web application may be obtained from a server by the web browser. Furthermore, the web application may be used to provide computationally intensive features, such as financial modeling, computational math or science, and/or AI, to a user. To implement such features in a practical manner, a native code module associated with the web application may be obtained (operation404). For example, the native code module may be downloaded from a source specified by the web application. The native code module may also be validated (operation406) prior to executing the native code module. If the native code module is not validated, the native code module is not executed and discarded.

If the native code module is validated, the native code module is loaded into a secure runtime environment (operation408). The secure runtime environment may be provided by a plugin associated with the web browser. Next, input data associated with the web application is provided to the native code module (operation410). The input data may be provided to the native code module using an IMC buffer.

The input data is then processed by the native code module (operation412) to obtain output data (operation414). The output data is then provided to the web application (operation416) for use by the web application. As with the input data, the output data may be provided to the web application using an IMC buffer. For example, the application may use the output data for simulation, signal processing, artificial intelligence, modeling, and/or analysis. In addition, the output data may optionally be provided to a trusted plugin (operation418) associated with the web application for use by the trusted plugin. For example, the output data may be used by the trusted plugin to render graphics for the web application.

The foregoing descriptions of embodiments of the system have been presented only for purposes of illustration and description. They are not intended to be exhaustive or to limit the system to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the system. The scope of the present system is defined by the appended claims.