Method and System for Stealing Interrupt Vectors

• US 20080301402A1
• Filed: 06/04/2007
• Published: 12/04/2008
• Est. Priority Date: 06/04/2007
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Herold, Brad Lee, Kapoor, Shakti, Alapati, Sangram, Patrascu, Alexandru Adrian
• Granted Patent: US 8,145,819 B2
• Time in Patent Office: Days
• US Class Current: 712/7
• CPC Class Codes: G06F 9/4812 by interrupt, e.g. masked

Abstract

A system for stealing interrupt vectors from an operating system. Custom interrupt handler extensions are copied into an allocated block of memory from a kernel module. Also, operating system interrupt handlers are copied into a reserved space in the allocated block of memory from an interrupt vector memory location. In response to copying the operating system interrupt handlers into the reserved space in the allocated block of memory, custom interrupt handlers from the kernel module are copied over the operating system interrupt handlers in the interrupt vector memory location. The custom interrupt handlers after being copied into the interrupt vector memory location handle all interrupts received by the operating system.

Claims

1. A computer implemented method for stealing interrupt vectors from an operating system, the computer implemented method comprising:

copying custom interrupt handler extensions into an allocated block of memory from a kernel module;

copying operating system interrupt handlers into a reserved space in the allocated block of memory from an interrupt vector memory location;

responsive to copying the operating system interrupt handlers into the reserved space in the allocated block of memory, copying custom interrupt handlers from the kernel module over the operating system interrupt handlers in the interrupt vector memory location, wherein the custom interrupt handlers after being copied into the interrupt vector memory location handle all interrupts received by the operating system.

2. The computer implemented method of claim 1, further comprising:

responsive to the operating system receiving an interrupt, branching to one of the custom interrupt handler extensions from one of the custom interrupt handlers that is associated with the interrupt, wherein the one of the custom interrupt handler extensions corresponds with the one of the custom interrupt handlers;

determining if special processing is required by the one of the custom interrupt handler extensions;

responsive to determining that special processing is required by the one of the custom interrupt handler extensions, continuing to custom interrupt code; and

returning from the interrupt.

3. The computer implemented method of claim 2, further comprising:

responsive to determining that special processing is not required by the one of the custom interrupt handler extensions, restoring registers to a state at a time of the interrupt, wherein the registers are in one or more processing units.

4. The computer implemented method of claim 3, further comprising:

generating a kernel thread for each of the one or more processing units to form a generated kernel thread for each of the one or more processing units, wherein the generated kernel thread of a master processing unit copies the custom interrupt handlers over the operating system interrupt handlers in the interrupt vector memory location.

5. The computer implemented method of claim 4, further comprising:

disabling external interrupts in each generated kernel thread;

determining if the master processing unit is finished copying the custom interrupt handlers over the operating system interrupt handlers; and

responsive to determining that the master processing unit is finished copying the custom interrupt handlers over the operating system interrupt handlers, restoring the external interrupts.

6. The computer implemented method of claim 1, wherein the allocated block of memory is large enough to store the custom interrupt handler extensions and the operating system interrupt handlers.

7. The computer implemented method of claim 1, wherein the reserved space is located directly after each of the custom interrupt handler extensions in the allocated block of memory.

8. The computer implemented method of claim 1, wherein the allocated block of memory is contained within a real memory device, and wherein the real memory device is a volatile memory device.

9. The computer implemented method of claim 1, wherein the allocated block of memory is a contiguous block of memory.

10. The computer implemented method of claim 1, wherein each of the operating system interrupt handlers are associated with a custom interrupt handler extension.

11. The computer implemented method of claim 1, wherein the custom interrupt code executes a test program to test system resources, and wherein the custom interrupt code includes hooks to access a lowest level of system resources.

12. The computer implemented method of claim 5, wherein the copying, generating, disabling, determining if the master processing unit is finished copying, and restoring steps are performed by a kernel module.

13. The computer implemented method of claim 12, wherein the kernel module includes operating system interrupt vector stealing code.

14. The computer implemented method of claim 2, wherein the branching, determining if special processing is required, continuing, and returning steps are performed by a custom interrupt handler.

15. The computer implemented method of claim 11, wherein a superuser installs the kernel module on the operating system.

16. The computer implemented method of claim 1, wherein the operating system is an advanced interactive executive operating system.

17. A data processing system for stealing interrupt vectors from an operating system, comprising:

a bus system;

a storage device connected to the bus system, wherein the storage device includes a set of instructions; and

a processing unit connected to the bus system, wherein the processing unit executes the set of instructions to copy custom interrupt handler extensions into an allocated block of memory from a kernel module;

copy operating system interrupt handlers into a reserved space in the allocated block of memory from an interrupt vector memory location;

copy custom interrupt handlers from the kernel module over the operating system interrupt handlers in the interrupt vector memory location in response to copying the operating system interrupt handlers into the reserved space in the allocated block of memory, wherein the custom interrupt handlers after being copied into the interrupt vector memory location handle all interrupts received by the operating system.

18. A computer program product for stealing interrupt vectors from an operating system, the computer program product comprising:

a computer usable medium having computer usable program code embodied therein, the computer usable medium comprising;

computer usable program code configured to copy custom interrupt handler extensions into an allocated block of memory from a kernel module;

computer usable program code configured to copy operating system interrupt handlers into a reserved space in the allocated block of memory from an interrupt vector memory location;

computer usable program code configured to copy custom interrupt handlers from the kernel module over the operating system interrupt handlers in the interrupt vector memory location in response to copying the operating system interrupt handlers into the reserved space in the allocated block of memory, wherein the custom interrupt handlers after being copied into the interrupt vector memory location handle all interrupts received by the operating system.

19. The computer program product of claim 18, further comprising:

computer usable program code configured to branch to one of the custom interrupt handler extensions from one of the custom interrupt handlers that is associated with an interrupt in response to the operating system receiving the interrupt, wherein the one of the custom interrupt handler extensions corresponds with the one of the custom interrupt handlers;

computer usable program code configured to determine if special processing is required by the one of the custom interrupt handler extensions;

computer usable program code configured to continue to custom interrupt code in response to determining that special processing is required by the one of the custom interrupt handler extensions; and

computer usable program code configured to return from the interrupt.

20. The computer program product of claim 19, further comprising:

computer usable program code configured to restore registers to a state at a time of the interrupt in response to determining that special processing is not required by the one of the custom interrupt handler extensions, wherein the registers are in one or more processing units.