Method and apparatus for run-time in-memory patching of code from a service processor

• US 20080083030A1
• Filed: 09/29/2006
• Published: 04/03/2008
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: Nuovo Pignone Holding SPA (Baker Hughes Company), Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Khosravi, Hormuzd M., Schluessler, Travis, Durham, David M., Savagaonkar, Uday R., Sahita, Ravi
• Granted Patent: US 8,286,238 B2
• Time in Patent Office: Days
• US Class Current: 726/22
• CPC Class Codes: G06F 8/656 while running

Abstract

Methods and apparatuses enable in-memory patching of a program loaded in volatile memory. A service processor identifies a program to be patched and an associated patch for the program. The patch is loaded into memory, including applying relocation fix-ups to the patch. The service processor directs the program to the patch in place of the segment of the program to be patched. The program implements the patch while maintaining program state, and without suspending execution of the program.

Claims

1. A method for patching a program, comprising:

identifying an item loaded in memory to be patched, the item associated with a program loaded in memory;

storing a patch for the item in volatile memory;

directing the program to the patch to cause the program to implement the patch while maintaining state for the program and without suspending execution of the program.

2. The method of claim 1, wherein identifying the item comprises:

identifying a segment of program code.

3. The method of claim 1, wherein identifying the item comprises:

identifying a locatable data element.

4. The method of claim 1, wherein storing the patch in the volatile memory further comprises:

applying relocation fix-ups to the patch.

5. The method of claim 1, wherein storing the patch in the volatile memory further comprises:

modifying a symbol lookup table.

6. The method of claim 1, wherein directing the program to the patch further comprises:

locking the item associated with the program to prevent access to the item;

directing the program to the patch while the item is locked; and

removing the lock condition on the item.

7. The method of claim 6, wherein locking the item comprises:

marking a memory page containing the item as not present in the volatile memory;

directing the program to the patch; and

marking the memory page as present in the volatile memory after directing the program to the patch.

8. The method of claim 1, further comprising:

determining whether memory pages containing the program are loaded in volatile memory; and

if not, loading the memory pages into volatile memory prior to directing the program to the patch.

9. The method of claim 1, wherein the item comprises a named function of the program, and wherein directing the program to the patch comprises:

replacing symbol references of the program from referencing the item to referencing the patch.

10. The method of claim 1, further comprising:

reporting an outcome of patching the program to a remote administrator over a network connection inaccessible to software executing on a host processor that executes the program.

11. An article of manufacture comprising a machine-readable medium having content stored thereon to provide instructions to result in a device performing operations including:

receiving a patch from a patch source to apply to a program loaded in volatile memory;

replacing inline an instruction of the program with a jump to the patch.

12. The article of manufacture of claim 11, wherein receiving the patch from the patch source comprises:

receiving the patch from platform hardware.

13. The article of manufacture of claim 12, wherein receiving the patch from platform hardware comprises:

receiving the patch from a service processor.

14. The article of manufacture of claim 11, wherein receiving the patch from the patch source comprises:

receiving the patch from a remote management console.

15. The article of manufacture of claim 11, wherein receiving the patch from the patch source comprises:

receiving the patch from a virtual machine executing on the platform hardware.

16. The article of manufacture of claim 15, wherein receiving the patch from the patch source comprises:

receiving the patch from a software component of the operating environment of the program.

17. The article of manufacture of claim 11, the content to further provide instructions for:

applying fix-ups to the patch.

18. A service processor comprising:

a receiver to receive an indication of a program to patch, identify a segment of the program in virtual memory to be patched, and identify a patch for the segment of the program;

a patch application module coupled to the receiver to apply relocation fix-ups to the patch, load the patch into volatile memory, and direct the program to the patch in place of the segment of the program to apply the patch in-memory without reloading the program into volatile memory.

19. The service processor of claim 18, wherein the patch application module to direct the program to the patch comprises the patch application module to further:

replace an instruction in a sequence of instructions of the segment of the program with a control flow transfer instruction to the patch to redirect the sequence of instructions to the patch;

copy the replaced instruction into the patch; and

insert a control flow transfer instruction at an end of the instructions of the patch to direct the sequence of instructions to return to the program.

20. The service processor of claim 19, wherein the patch application module to insert the control flow transfer instruction at the end of the instructions of the patch to direct the sequence of instructions to return to the program comprises the patch application module to further:

insert the control flow transfer instruction to direct the sequence of instructions to return to the program at a location in the program that avoids executing one or more instructions of the sequence of instructions of the program.

21. The service processor of claim 18, further comprising:

a registration module to register the program prior to receiving the indication of the program to patch.

22. A system comprising:

a patch agent having a receiver to receive an indication of a program to patch, identify a segment of the program in virtual memory to be patched, and identify a patch for the segment of the program;

a registration module to register the program prior to receiving the indication of the program to patch; and

a patch application module coupled to the receiver to apply relocation fix-ups to the patch, load the patch into volatile memory, and direct the program to the patch in place of the segment of the program to apply the patch in-memory without reloading the program into volatile memory.

a flash storage coupled to the patch agent to store the registration information for the program.

23. The system of claim 22, the patch agent further comprising:

a memory scanner to scan the program for malware; and

if malware is detected, to initiate a patch to avoid the malware code in the program.

24. The system of claim 22, wherein the receiver to receive the indication of the program to patch comprises the receiver to receive an indication of an update or patch available for the registered program.