G06F9/4486

Determining caller of a module in real-time

Methods, systems and computer program products for determining a caller of a module in real-time is provided. Each listed target module is located and loaded into system memory. A link is established between each target module and the testing framework, which begins execution of an application that includes the plurality of target modules. In response to one of the plurality of target modules being called by the application, control is passed to the testing framework, which includes the passing to the testing framework original registers from the application and a register containing an entry point of the testing framework. The chain of load modules is inspected by following the linkage data provided in the registers, and the data is recorded. Control is returned from the testing framework to the target module.

Target injection safe method for inlining instance-dependent calls

A method for redirecting indirect calls to direct calls on a per-process basis includes accessing a memory code region of an operating system kernel that has a different mapping for each of one or more user processes running on the operating system kernel. The memory code region stores a first trampoline that refers directly to a second trampoline, which is an inline or outline trampoline that is correlated with a particular user process. Executing the first trampoline invokes the second trampoline, as a result of which the indirect calls are redirected to direct calls.

Secure identification of execution contexts

A virtual-machine-based system that identifies an application or process in a virtual machine in order to locate resources associated with the identified application. Access to the located resources is then controlled based on a context of the identified application. Those applications without the necessary context will have a different view of the resource.

Conditional Branch Frame Barrier
20210124583 · 2021-04-29 · ·

Establishing a conditional branch frame barrier is described. A conditional branch in a function epilogue is used to provide frame-specific control. The conditional branch evaluates a return condition to determine whether to return from a callee function to a calling function, or to execute a slow path instead. The return condition is evaluated based on a thread local value. The thread local value is set such that returns to potentially unsafe frames in a call stack are prohibited. The prohibition to return to a potentially unsafe frame may be referred to as a “frame barrier.” Additionally, the thread local value may be used to establish safepointing and/or thread local handshakes, both after execution of a function body and after execution of a loop body.

HARDWARE SECURE ELEMENT, RELATED PROCESSING SYSTEM, INTEGRATED CIRCUIT, DEVICE AND METHOD

A hardware secure element is described. The hardware secure element includes a microprocessor and a memory, such as a non-volatile memory. The memory stores a plurality of software routines executable by the microprocessor. Each software routine starts at a respective memory start address. The hardware secure element also includes a receiver circuit and a hardware message handler module. The receiver circuit is configured to receive command data that includes a command. The hardware message handler module is configured to determine a software routine to be executed by the microprocessor as a function of the command, and also configured to provide address data to the microprocessor that indicates the software routine to be executed.

Conditional branch frame barrier
10922081 · 2021-02-16 · ·

Establishing a conditional branch frame barrier is described. A conditional branch in a function epilogue is used to provide frame-specific control. The conditional branch evaluates a return condition to determine whether to return from a callee function to a calling function, or to execute a slow path instead. The return condition is evaluated based on a thread local value. The thread local value is set such that returns to potentially unsafe frames in a call stack are prohibited. The prohibition to return to a potentially unsafe frame may be referred to as a frame barrier. Additionally, the thread local value may be used to establish safepointing and/or thread local handshakes, both after execution of a function body and after execution of a loop body.

Target injection safe method for dynamically inlining branch predictions

A method for redirecting an indirect call in an operating system kernel to a direct call is disclosed. The direct calls are contained in trampoline code called an inline jump switch (IJS) or an outline jump switch (OJS). The IJS and OJS can operate in either a use mode, redirecting an indirect call to a direct call, a learning and update mode or fallback mode. In the learning and update mode, target addresses in a trampoline code template are learned and updated by a jump switch worker thread that periodically runs as a kernel process. When building the kernel binary, a plug-in is integrated into the kernel. The plug-in replaces call sites with a trampoline code template containing a direct call so that the template can be later updated by the jump switch worker thread.

TARGET INJECTION SAFE METHOD FOR INLINING INSTANCE-DEPENDENT CALLS
20210011722 · 2021-01-14 ·

A method for redirecting indirect calls to direct calls on a per-process basis includes accessing a memory code region of an operating system kernel that has a different mapping for each of one or more user processes running on the operating system kernel. The memory code region stores a first trampoline that refers directly to a second trampoline, which is an inline or outline trampoline that is correlated with a particular user process. Executing the first trampoline invokes the second trampoline, as a result of which the indirect calls are redirected to direct calls.

TARGET INJECTION SAFE METHOD FOR DYNAMICALLY INLINING BRANCH PREDICTIONS
20210011728 · 2021-01-14 ·

A method for redirecting an indirect call in an operating system kernel to a direct call is disclosed. The direct calls are contained in trampoline code called an inline jump switch (IJS) or an outline jump switch (OJS). The IJS and OJS can operate in either a use mode, redirecting an indirect call to a direct call, a learning and update mode or fallback mode. In the learning and update mode, target addresses in a trampoline code template are learned and updated by a jump switch worker thread that periodically runs as a kernel process. When building the kernel binary, a plug-in is integrated into the kernel. The plug-in replaces call sites with a trampoline code template containing a direct call so that the template can be later updated by the jump switch worker thread.

TARGET INJECTION SAFE METHOD FOR INLINING REGISTRATION CALLS
20210011738 · 2021-01-14 ·

A method of redirecting an indirect call in a callback list associated with a list of functions that are registered, includes the steps of: upon registering the list of functions, determining a list of function pointers, each of which corresponds to an address in an associated callback; for each function pointer in the list of function pointers, adding a direct call instruction to the registration trampoline corresponding to the associated callback of the function pointer; and upon invoking the associated callback of one of the function pointers in the list of function pointers, invoking the corresponding direct call instruction in the registration trampoline.