Execution of Subset of Driver Code in Separate Protection Domain

• US 20180314651A1
• Filed: 01/09/2018
• Published: 11/01/2018
• Est. Priority Date: 04/30/2017
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: VARMA, Shyamal, RAJEEV, Kumar, WIELAND, Peter William
• Granted Patent: US 10,445,257 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 11/0715 in a system implementing multitasking multitasking per se G06F9/46
• CPC Class Codes: G06F 13/102 where the programme performs an interfacing function, e.g. device driver G06F13/105 takes precedence; scheduling within device drivers G06F9/52; contention policies within device drivers G06F9/4881
• CPC Class Codes: G06F 21/53 by executing in a restricted environment, e.g. sandbox or secure virtual machine
• CPC Class Codes: G06F 21/57 Certifying or maintaining trusted computer platforms, e.g. secure boots or power-downs, version controls, system software checks, secure updates or assessing vulnerabilities
• CPC Class Codes: G06F 9/526 Mutual exclusion algorithms
• CPC Class Codes: G06F 9/545 where tasks reside in different layers, e.g. user- and kernel-space
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

Described herein is a system for driver execution. A driver is loaded in a first domain with the driver controlling an associated device. In response to a request from the driver, the driver companion is loaded in a second domain different than the first domain, the second domain comprising a secure environment. The driver companion communicates with the associated device. Communications between the driver and the driver companion are managed (e.g., by an operating system framework). In response to a request from the driver, the driver companion is unloaded.

Claims

1. A system for driver execution, comprising:

a computer comprising a processor and a memory having computer-executable instructions stored thereupon which, when executed by the processor, cause the computing device to;

load the driver in a first domain, wherein the driver controls an associated device;

in response to a request from the driver, load the driver companion in a second domain different than the first domain, the second domain comprising a secure environment, the driver companion communicates with the associated device;

manage communications between the driver and the driver companion; and

in response to a request from the driver, unload the driver companion.

2. The system of claim 1, wherein the driver executes in a kernel mode and the driver companion executes in a user mode.

3. The system of claim 1, wherein the driver executes in a first virtual trust level and the driver companion executes in a second higher virtual trust level.

4. The system of claim 1, wherein the driver executes in a first address space and the driver companion executes in a second different address space.

5. The system of claim 1, wherein the driver companion securely stores biometric information about a user of the computer.

6. The system of claim 1, wherein the driver companion securely stores at least one of an encryption key or a decryption key.

7. The system of claim 1, wherein the driver companion securely executes at least one of a sensitive input transaction or a sensitive output transaction.

8. The system of claim 1, wherein a task queue facilitates communications between the driver and the driver companion.

9. The system of claim 1, wherein a framework manages a lifetime associated with the driver companion.

10. The system of claim 1, wherein the driver manages a plug and play (PnP) state and a power state of a device associated with the driver.

11. A method of executing a driver and an associated driver companion, comprising:

loading the driver in a first domain, wherein the driver controls an associated device;

in response to a request from the driver, loading the driver companion in a second domain different than the first domain, the second domain comprising a secure environment, the driver companion communicating with the associated device;

managing communications between the driver and the driver companion; and

in response to a request from the driver, unloading the driver companion.

12. The method of claim 11, wherein the first domain is kernel mode and the second domain is user mode.

13. The method of claim 11, wherein the driver manages the associated device using the driver companion.

14. The method of claim 11, wherein the driver executes in a first address space and the driver companion executes in a second different address space.

15. The method of claim 11, wherein the driver companion securely stores information about a user of the computer.

16. A computer storage media storing computer-readable instructions that when executed cause a computing device to:

load a driver in a first domain, the driver controls an associated device;

in response to a request from the driver, load a driver companion in a second domain different than the first domain, the second domain comprising a secure environment, the driver companion communicates with the associated device;

manage communications between the driver and the driver companion; and

in response to a request from the driver, unload the driver companion.

17. The computer storage media of claim 16, wherein the first domain is kernel mode and the second domain is user mode.

18. The computer storage media of claim 16, wherein the first domain is a first virtual trust level and the second domain is a second higher virtual trust level.

19. The computer storage media of claim 16, wherein the driver executes in a first address space and the driver companion executes in a second different address space.

20. The computer storage media of claim 16, wherein the driver companion securely stores information about a user of the computer.