Intel Corporation

Deepak K Gupta

Ravi L Sahita

Vedvyas Shanbhogue

Barry E Huntley

Jason W Brandt

Baiju V Patel

David M Durham

Michael Lemay

Gilbert A Neiger

Joseph Frank Cihula

Andrew V Anderson

Joseph Nuzman

David A Koufaty

Asit K Mallick

Arumugam Thiyagarajah

Jacob Doweck

Mingwei Zhang

H Peter Anvin

Lihu Rappoport

Robert S Chappell

Sergiu D Ghetie

Rodrigo Branco

Jared Warner Stark, Iv

Scott P Bobholz

Wojciech S Powiertowski

Sagar V Dalvi

Ariel Sabba

David Hansen

Enrico Perla

Scott J Cape

Willem Pinckaers

Yair Berger

Gilad Holzstein

Hisham Shafi

Yogesh Bijlani

This disclosure is directed to a system for address mapping and translation protection. In one embodiment, processing circuitry may include a virtual machine manager (VMM) to control specific guest linear address (GLA) translations. Control may be implemented in a performance sensitive and secure manner, and may be capable of improving performance for critical linear address page walks over legacy operation by removing some or all of the cost of page walking extended page tables (EPTs) for critical mappings. Alone or in combination with the above, certain portions of a page table structure may be selectively made immutable by a VMM or early boot process using a sub-page policy (SPP). For example, SPP may enable non-volatile kernel and/or user space code and data virtual-to-physical memory mappings to be made immutable (e.g., non-writable) while allowing for modifications to non-protected portions of the OS paging structures and particularly the user space.

System for address mapping and translation protection

Methods and apparatuses relating to mitigations for speculative execution side channels are described. Speculative execution hardware and environments that utilize the mitigations are also described. For example, three indirect branch control mechanisms and their associated hardware are discussed herein: (i) indirect branch restricted speculation (IBRS) to restrict speculation of indirect branches, (ii) single thread indirect branch predictors (STIBP) to prevent indirect branch predictions from being controlled by a sibling thread, and (iii) indirect branch predictor barrier (IBPB) to prevent indirect branch predictions after the barrier from being controlled by software executed before the barrier.

Apparatuses and methods for speculative execution side channel mitigation

A processor implementing techniques for processor extensions to protect stacks during ring transitions is provided. In one embodiment, the processor includes a plurality of registers and a processor core, operatively coupled to the plurality of registers. The plurality of registers is used to store data used in privilege level transitions. Each register of the plurality of registers is associated with a privilege level. An indicator to change a first privilege level of a currently active application to a second privilege level is received. In view of the second privilege level, a shadow stack pointer (SSP) stored in a register of the plurality of registers is selected. The register is associated with the second privilege level. By using the SSP, a shadow stack for use by the processor at the second privilege level is identified.

Processor extensions to protect stacks during ring transitions

Methods and apparatuses relating to switching of a shadow stack pointer are described. In one embodiment, a hardware processor includes a hardware decode unit to decode an instruction, and a hardware execution unit to execute the instruction to: pop a token for a thread from a shadow stack, wherein the token includes a shadow stack pointer for the thread with at least one least significant bit (LSB) of the shadow stack pointer overwritten with a bit value of an operating mode of the hardware processor for the thread, remove the bit value in the at least one LSB from the token to generate the shadow stack pointer, and set a current shadow stack pointer to the shadow stack pointer from the token when the operating mode from the token matches a current operating mode of the hardware processor.

Hardware apparatuses and methods to switch shadow stack pointers

Systems, methods, and apparatuses relating to circuitry to implement individually revocable capabilities for enforcing temporal memory safety are described. In one embodiment, a hardware processor comprises an execution unit to execute an instruction to request access to a block of memory through a pointer to the block of memory, and a memory controller circuit to allow access to the block of memory when an allocated object tag in the pointer is validated with an allocated object tag in an entry of a capability table in memory that is indexed by an index value in the pointer, wherein the memory controller circuit is to clear the allocated object tag in the capability table when a corresponding object is deallocated.

Hardware apparatuses, methods, and systems for individually revocable capabilities for enforcing temporal memory safety

An apparatus and method for efficient process-based compartmentalization. For example, one embodiment of a processor comprises: execution circuitry to execute instructions and process data; memory management circuitry coupled to the execution circuitry, the memory management circuitry to manage access to a system memory by a plurality of related processes using one or more process-specific translation structures and one or more shared translation structures to be shared by the related processes; and one or more control registers to store a process-specific base address pointer associated with a first process of the plurality of related processes and to store a shared base address pointer to identify the shared translation structures; wherein the memory management circuitry is to use the process-specific base address pointer in combination with a first linear address provided by the first process to walk the process-specific translation structures to identify any permissions and/or physical address associated with the first linear address, wherein if permissions are identified, the memory management circuitry is to use the permissions in place of any permissions specified in the shared translation structures.

Apparatus and method for efficient process-based compartmentalization

An apparatus and method for efficiently managing shadow stacks. For example, one embodiment of a processor comprises: a plurality of registers to store a plurality of shadow stack pointers (SSPs); event processing circuitry to select a first SSP of the plurality of SSPs from a first register of the plurality of registers responsive to receipt of a first event associated with a first event priority level, the first SSP usable to identify a top of a first shadow stack; verification and utilization checking circuitry to determine whether the first SSP has been previously verified, wherein if the first SSP has not been previously verified then initiating a set of atomic operations to verify the first SSP and confirm that the first SSP is not in use, the set of atomic operations using a locking operation to lock data until the set of atomic operations are complete.

Shadow stack ISA extensions to support fast return and event delivery (FRED) architecture

Systems, methods, and apparatuses relating to instructions to compartmentalize memory accesses and execution (e.g., non-speculative and speculative) are described. In one embodiment, a compartment manager circuit is to determine, when a compartment control register of a hardware processor core is set to an enable value, that a first subset of code requested for execution on the hardware processor core in user privilege is within a first compartment of memory, load a first compartment descriptor for the first compartment into one or more registers of the hardware processor core from the memory, check if the first compartment is marked in the first compartment descriptor, within the one or more registers of the hardware processor core, as a management compartment, and, when the first compartment is marked in the first compartment descriptor as the management compartment, allowing the first subset of the code within the first compartment to load a second compartment descriptor for a second compartment of the memory into the one or more registers of the hardware processor core from the memory, switching execution from the first subset of code within the first compartment to a second subset of code in user privilege within the second compartment, allowing speculative memory accesses for the second subset of code only within the second compartment, and preventing a memory access outside of the second compartment for the second subset of code as indicated by the second compartment descriptor stored within the one or more registers of the hardware processor core.

Apparatuses, methods, and systems for instructions to compartmentalize code

An apparatus and method for memory management using compartmentalization. For example, one embodiment of a processor comprises: execution circuitry to execute instructions and process data, at least one instruction to generate a system memory access request using a first linear address; and address translation circuitry to perform a first walk operation through a set of one or more address translation tables to translate the first linear address to a first physical address, the address translation circuitry to concurrently perform a second walk operation through a set of one or more linear address metadata tables to identify metadata associated with the linear address, and to use one or more portions of the metadata to validate access by the at least one instruction to the first physical address.

Memory management apparatus and method for compartmentalization using linear address metadata

An apparatus and method for efficiently managing shadow stacks. For example, one embodiment of a processor comprises: a plurality of registers to store a plurality of shadow stack pointers (SSPs), each SSP associated with a different event priority; event processing circuitry to select a first SSP of the plurality of SSPs from a first register of the plurality of registers responsive to receipt of a first event associated with a first event priority level, the first SSP usable to identify a top of a first shadow stack; verification and utilization checking circuitry to determine whether the first SSP has been previously verified, wherein if the first SSP has not been previously verified then initiating a set of atomic operations to verify the first SSP and confirm that the first SSP is not in use, the set of atomic operations using a locking operation to lock data until the set of atomic operations are complete, and wherein if the first SSP has been previously verified, then re-verifying the first SSP and confirming that the first SSP is not in use without using the locking operation.

Growing community of inventors

Hillsboro, OR, United States of America

Deepak K Gupta