Patent classifications
G06F8/434
METHODS AND APPARATUS TO PROTECT MEMORY FROM BUFFER OVERFLOW AND/OR UNDERFLOW
A disclosed example to protect memory from buffer overflow or underflow includes defining an implicit bound pointer based on an implicit bound pointer definition in a configuration file for a memory region; instrumenting object code with an implicit buffer bound check based on the implicit bound pointer; and generating hardened executable object code based on the object code, the implicit buffer bound check, and the implicit bound pointer, the implicit bound pointer located in the hardened executable object code during a compilation phase to facilitate loading the implicit bound pointer in a global bounds table during runtime for access by the implicit buffer bound check.
Predicting a table of contents pointer value responsive to branching to a subroutine
Predicting a Table of Contents (TOC) pointer value responsive to branching to a subroutine. A subroutine is called from a calling module executing on a processor. Based on calling the subroutine, a value of a pointer to a reference data structure, such as a TOC, is predicted. The predicting is performed prior to executing a sequence of one or more instructions in the subroutine to compute the value. The value that is predicted is used to access the reference data structure to obtain a variable value for a variable of the subroutine.
Compiling optimized entry points for local-use-only function pointers
Embodiments relate to using a local entry point with an indirect call function. A compiler is provided to determine and indicate in the program code that the function pointer value resulting from a non-call reference of a function symbol is solely used to perform indirect calls in the same module, e.g. local-use-only. The compiler loads an address of a function through use of a symbolic reference. When the compiler determines that the value employed by the symbolic reference is used exclusively to perform an indirect function call, the compiler proceeds to resolve a local entry point address of the function, thereby reducing a quantity of operations to be executed.
PREDICTING A TABLE OF CONTENTS POINTER VALUE RESPONSIVE TO BRANCHING TO A SUBROUTINE
Predicting a Table of Contents (TOC) pointer value responsive to branching to a subroutine. A subroutine is called from a calling module executing on a processor. Based on calling the subroutine, a value of a pointer to a reference data structure, such as a TOC, is predicted. The predicting is performed prior to executing a sequence of one or more instructions in the subroutine to compute the value. The value that is predicted is used to access the reference data structure to obtain a variable value for a variable of the subroutine.
Dynamic memory allocation methods and systems
In a dynamic memory allocator, a method of allocating memory to a process, the method comprising executing on a processor the steps of: creating one or more arenas within the memory, each arena comprising one or more memory blocks and each arena having an n-byte aligned arena address; upon receiving a memory request from the process, returning a pointer to the process, the pointer having as its value an address of a memory block selected from one of the arenas; upon determining that the memory block is no longer needed by the process, retrieving the address of said memory block from the pointer and releasing the memory block; and, upon a new arena being created, shifting forward the n-byte aligned address of said new arena according to a stored variable such that each memory block of said new arena is also shifted by the stored variable, the stored variable having n bytes and the stored variable having a random value.
SOFTWARE CODE VERIFICATION USING CALL GRAPHS FOR AUTONOMOUS SYSTEMS AND APPLICATIONS
In various examples, techniques for performing software code verification are described. Systems and methods are disclosed for generating, using intermediate code and user input, a call graph that represents source code for software. For instance, the call graph represents at least functions (e.g., internal functions, external functions, etc.) associated with the software, calls (e.g., direct calls, call pointers, etc.) between the functions, and register information associated with the functions (e.g., variables used by the functions, assembly code used by the functions, etc.). The systems and methods may further use the call graph to perform software code verification by verifying rules from design specifications for the software and/or rules from various certification standards.
Processor that includes a special store instruction used in regions of a computer program where memory aliasing may occur
Processor hardware detects when memory aliasing occurs, and assures proper operation of the code even in the presence of memory aliasing. The processor defines a special store instruction that is different from a regular store instruction. The special store instruction is used in regions of the computer program where memory aliasing may occur. Because the hardware can detect and correct for memory aliasing, this allows a compiler to make optimizations such as register promotion even in regions of the code where memory aliasing may occur.
PROCESSOR THAT INCLUDES A SPECIAL STORE INSTRUCTION USED IN REGIONS OF A COMPUTER PROGRAM WHERE MEMORY ALIASING MAY OCCUR
Processor hardware detects when memory aliasing occurs, and assures proper operation of the code even in the presence of memory aliasing. The processor defines a special store instruction that is different from a regular store instruction. The special store instruction is used in regions of the computer program where memory aliasing may occur. Because the hardware can detect and correct for memory aliasing, this allows a compiler to make optimizations such as register promotion even in regions of the code where memory aliasing may occur.
Flow control for language-embedded programming in general purpose computing on graphics processing units
The present invention discloses a method of flow control in a computing device, for processing of flow control statements to adapt a data structure of a program running on the computing device and a computer program product storing the method. The invention thereby allows the integration of the kernels into the main program when compiling. The whole parsing of the CPU program parts and the kernels is done by 10 one single standard compiler. The actual compiler for the device can be linked as a library and does not need to do any parsing. The invention further allows loops and if-clauses to be used in language-embedded GPGPU programming, enabling full general-purpose programming of the device in a way that is fully embedded in an ordinary programming language. The device can be a highly parallel computing 15 device, such as a video card, or some other computing device.
Multi-version asynchronous dynamic software update system and method for applications with multiple threads
A method and system for using multiple versions of a software component, includes storing, in memory, a first function table that points to executable code in the memory for functions from a first version of the software component, and storing, in the memory, a second function table that points to executable code in the memory for functions from a second version of the software component, referencing the first function table, when running a first application thread, to execute the functions from the first version of the software component; and referencing the second function table, when running a second application thread that is active concurrently with the first application thread, to execute the functions from the second version of the software component.