Microsoft Technology Licensing, LLC

Mihai-Dan Budiu

Martin Abadi

Ulfar Erlingsson

Jay A Ligatti

Andrew William Fitzgibbon

Mark James Finocchio

Jamie Shotton

Duncan Paul Robertson

Richard E Moore

A computerized decision tree training system may include a distributed control processing unit configured to receive input of training data for training a decision tree. The system may further include a plurality of data batch processing units, each data batch processing unit being configured to evaluate each of a plurality of split functions of a decision tree for respective data batch of the training data, to thereby compute a partial histogram for each split function, for each datum in the data batch. The system may further include a plurality of node batch processing units configured to aggregate the associated partial histograms for each split function to form an aggregated histogram for each split function for each of a subset of frontier tree nodes and to determine a selected split function for each frontier tree node by computing the split function that produces highest information gain for the frontier tree node.

Distributed decision tree training

Instruction set architecture (ISA) extension support is described for control-flow integrity (CFI) and for XFI memory protection. ISA replaces CFI guard code with single instructions. ISA support is provided for XFI in the form of bounds-check instructions. Compared to software guards, hardware support for CFI and XFI increases the efficiency and simplicity of enforcement. In addition, the semantics for CFI instructions allows more precise static control-flow graph encodings than were possible with a prior software CFI implementation.

Architectural support for software-based protection

Software control flow integrity is provided by embedding identifying bit patterns at computed control flow instruction sources and destinations. The sources and destinations of computed control flow instructions are determined with reference to a control flow graph. The identifying bit patterns are compared during software execution, and a match between a source and a respective destination ensures control flow consistent with the control flow graph. Security measures are implemented when the comparison results in a mismatch, indicating that control flow has deviated from the anticipated course.

Software security based on control flow integrity

Software memory access control is provided by associating instruction areas with memory areas such that instruction areas are not permitted to access memory areas with which they are not associated. Checks may be inserted in the instruction areas to ensure that data provided by a memory group is provided by an associated memory area. Additionally, control flow integrity for the instruction areas may be provided by embedding identifying bit patterns within computed control flow instructions contained in the instruction groups. In this way, control flow of the instruction areas may be provided, thus preventing diversion of control flow and minimizing required checks.

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Mihai-Dan Budiu