Process identifier transition monitoring and assessment

Abstract

A process identifier transition monitor captures and assesses activities associated with a microprocessor or a microcontroller. Monitoring and assessment is performed by detection of process identifier transitions, which may be driven by an occurrence of one or more activities, such as execution of application software, system hardware mechanisms, or processor-internal mechanisms. Process identifier transitions are assessed to determine whether such transitions were expected. If a detected process identifier transition was not expected, then a system alert may be transmitted or some other appropriate response taken within the system.

What is claimed is: 
     
         1 . A data processing system comprising:
 a processor;   a process identifier unit configured to track process identifier values associated with activities occurring within the processor; and   a process identifier transition monitor configured to determine when a transition of the tracked process identifier values from a first value to a second value is illegitimate.   
     
     
         2 . The data processing system as recited in  claim 1 , further comprising the process identifier transition monitor configured to output a signal as a function of a determination that the transition of the tracked process identifier values is illegitimate. 
     
     
         3 . The data processing system as recited in  claim 1 , wherein the illegitimate transition of the tracked process identifier values represents an occurrence of a certain activity within the data processing system. 
     
     
         4 . The data processing system as recited in  claim 1 , wherein the illegitimate transition of the tracked process identifier values represents an error in an execution of application software in the processor or an occurrence of a cyberattack received within the data processing system. 
     
     
         5 . The data processing system as recited in  claim 1 , wherein the illegitimate transition of the tracked process identifier values represents an unexpected execution in the processor of a certain first thread after execution of a certain second thread. 
     
     
         6 . The data processing system as recited in  claim 1 , wherein the process identifier transition monitor includes a lookup table configured to contain entries that indicate which transitions of tracked process identifier values are legitimate and which transitions of tracked process identifier values are illegitimate. 
     
     
         7 . The data processing system as recited in  claim 6 , wherein the process identifier transition monitor is configured to capture the first and second values of the tracked process identifier and perform a lookup of the transition in the lookup table to determine whether the transition has been predetermined to be legitimate or illegitimate. 
     
     
         8 . The data processing system as recited in  claim 2 , wherein the process identifier transition monitor is configured to select a predetermined response associated with the illegitimate transition, wherein the signal is delivered to a portion of the data processing system as a function of the selected predetermined response. 
     
     
         9 . The data processing system as recited in  claim 2 , wherein the signal is configured to cause a vehicle to shut down its drive train or a warning to be transmitted to a driver or passenger of the vehicle. 
     
     
         10 . The data processing system as recited in  claim 6 , wherein a legitimate transition of process identifier values represents an expected or acceptable activity occurring within the processor, and wherein an illegitimate transition of process identifier values represents an unexpected, unacceptable, undesirable, unwanted, or erroneous activity occurring within the processor. 
     
     
         11 . A method comprising:
 monitoring a transition of process identifier values tracked within a data processing system; and   determining when the transition of process identifier values represents an illegitimate transition of the process identifier values.   
     
     
         12 . The method as recited in  claim 11 , wherein the monitoring of the transition of process identifier values further comprises:
 capturing a first process identifier value from a process identifier unit associated with a processor; and   capturing a second process identifier value from the process identifier unit,   wherein the determining when the transition of process identifier values represents the illegitimate transition of the process identifier values further comprises using the first and second captured process identifier values to perform a lookup in a lookup table, resulting in the determination that the transition of process identifier values represents the illegitimate transition.   
     
     
         13 . The method as recited in  claim 11 , further comprising triggering a predetermined response as a function of the determining of the illegitimate transition of the process identifier values. 
     
     
         14 . The method as recited in  claim 13 , wherein the predetermined response is a reset of the processor to a predetermined known state. 
     
     
         15 . The method as recited in  claim 13 , wherein the predetermined response is a signal sent to a vehicle system controller that is configured to perform a specified function in response to the signal. 
     
     
         16 . The method as recited in  claim 11 , wherein the illegitimate transition represents an occurrence of a certain activity within a processor within the data processing system. 
     
     
         17 . The method as recited in  claim 16 , wherein the certain activity is selected from the group consisting of an execution of unexpected software code by the processor, an occurrence of a cyberattack received within the data processing system, a failure of a hardware mechanism external to the processor in the data processing system, and a failure or error occurring in the processor. 
     
     
         18 . A data processing system comprising:
 a processor;   a process identifier unit configured to track process identifier values associated with activities occurring within the processor; and   a process identifier transition monitor configured to determine whether a transition of the tracked process identifier values from a first value to a second value is legitimate or illegitimate, wherein the process identifier transition monitor further comprises:
 circuitry for capturing the first process identifier value from the process identifier unit; 
 circuitry for capturing the second process identifier value from the process identifier unit; 
 circuitry for performing a lookup in a permission matrix configured to contain entries that indicate which transitions of tracked process identifier values are legitimate and which transitions of tracked process identifier values are illegitimate; 
 circuitry for determining from the entries in the permission matrix that the transition of the tracked process identifier values from the first value to the second value represents an illegitimate transition of process identifier values; and 
 circuitry for triggering a predetermined response to the determination that the transition of the tracked process identifier values from the first value to the second value represents an illegitimate transition of process identifier values. 
   
     
     
         19 . The data processing system as recited in  claim 18 , wherein the illegitimate transition of the tracked process identifier values represents the processor entering an unknown or unexpected state of operation. 
     
     
         20 . The data processing system as recited in  claim 19 , wherein the predetermined response is selected from the group consisting of resetting the processor to a known state of operation, rebooting the processor, and deactivating the data processing system.