US 2006/0242402 A1 · Recovering device drivers

Abstract

A solution to the problem of maintaining application integrity when device drivers fail. This solution employs a new mechanism, the shadow driver, which is an operating system (OS) kernel agent that monitors communication between the OS kernel and the device driver it “shadows.” When a device driver error occurs, the shadow driver acts in place of the failed device driver, intercepting and responding to calls from the OS kernel and the device driver during cleanup, unloading, reloading, and re-initialization of the failed device driver. Applications and the OS kernel are thus isolated from the failure. An initial embodiment was developed for use with the Linux™ OS and was tested with a dozen device drivers. Results demonstrate that shadow drivers successfully mask device driver failures from applications, impose minimal performance overhead, require no changes to existing applications and device drivers, and can be implemented with relatively little code.

Claims27

Dependent claims

A method for recovering from a failure of a component executing on a computing device, comprising the steps of:

(a) monitoring communications between the component and an extensible system on the computing device;
(b) storing data for the component that were derived from the communications;
(c) detecting a failure of the component;
(d) responsive to detecting the failure, temporarily halting interaction of the component with the extensible system;
and
(e) re-initializing the component using the data that were stored, so that the component is restored to full functionality and is enabled to again interact with the extensible system.

3 more elements

A system that is able to recover from a failure of a device driver that is executed on the system, comprising:

(a) a memory in which machine instructions are stored, the machine instructions being used to implement an operating system (OS) kernel, a device driver, and a shadow driver;
and
(b) a processor coupled in communication with the memory, the processor executing the machine instructions to implement a plurality of functions, including:
(i) running the OS kernel, the device driver, and the shadow driver, by executing the machine instructions provided for each;
(ii) employing the shadow driver for monitoring communications between the device driver and the OS kernel, to determine a state of the device driver;
(iii) storing the state of the device driver in the memory;
(iv) detecting when a failure of the device driver has occurred;
(v) in response to a failure of the device driver being detected, temporarily interrupting communications between the device driver and the OS kernel, and employing the shadow driver to successively unload the device driver, reload the device driver, and re-initialize the device driver to the state that was stored in the memory;
and
(vi) restoring communications between the device driver that has been re-initialized and the OS kernel, so that the device driver is recovered from the failure.

7 more elements

Dependencies are inferred from the claim text.

Recovering device drivers

Life of this patent

Recovering device drivers

Life of this patent

Abstract

Claims27