Systems and methods for replicating virtual memory on a host computer and debugging using replicated memory

• US 7,360,115 B2
• Filed: 03/08/2006
• Issued: 04/15/2008
• Est. Priority Date: 09/22/2000
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Hogdal, Gregory, Eldridge, John R.
• Primary Examiner(s): MCCARTHY, CHRISTOPHER S
• Application Number:
  US11/276,644
• Publication Number:
  US 20060139316A1
• Time in Patent Office: 769 Days
• Field of Search: 714/25, 714/27, 714/9, 714/5, 714/38, 711/6, 711/203, 711205-207, 717/124, 717/127
• US Class Current: 714/27
• CPC Class Codes: G06F 11/3636 by tracing the execution of the program
• CPC Class Codes: G06F 11/366 using diagnostics G06F11/0703 takes precedence
• CPC Class Codes: G06F 12/10 Address translation
• CPC Class Codes: G06F 12/1027 using associative or pseudo-associative address translation means, e.g. translation look-aside buffer [TLB]
• CPC Class Codes: G06F 12/145 the protection being virtual, e.g. for virtual blocks or segments before a translation mechanism

Abstract

Systems and methods are described for replicating virtual memory translation from a target computer on a host computer, and debugging a fault that occurred on the target computer on the host computer. The described techniques are utilized on a target computer having a processor that has halted execution. Virtual to physical address translation data from the target computer is transferred to the host computer. The host computer utilizes the virtual to physical address translation data to access data pointed by virtual memory addresses that were used by the target computer, and then debugs a fault by accessing the data by reading the physical memory address on the host computer. After the virtual to physical memory address translation data have been acquired, they can be cached at the host computer.

Claims

1. A method, comprising:

accessing address tables from physical memory of a target computer system;

replicating the address tables on a computing system; and

using data contained in the address tables to derive virtual memory data that was used on the target computer system;

wherein a kernel of the target computer system uses physical memory data of the target computer system for debugging and adds mapping of the address tables into a physical address;

wherein the virtual memory data on the computing system is not identical to virtual memory data on the target computer system.

2. The method as recited in claim 1, further comprising storing the address tables in memory on the computing system.

3. The method as recited in claim 1, further comprising caching the virtual memory data on the computing system.

4. The method as recited in claim 1, further comprising determining if memory management of the target computer system processor is enabled.

5. The method as recited in claim 1, further comprising performing the method only if memory management of the target computer system processor is enabled.

6. The method as recited in claim 1, wherein the accessing further comprises:

locating the address tables in physical memory of the target computer; and

reading the address tables from the target computer.

7. The method as recited in claim 1, further comprising validating the virtual memory data to ensure it is identical to the virtual memory data stored on the target computer.

8. The method as recited in claim 1, further comprising debugging a fault that occurred on the target computer by analyzing the virtual memory data on the computing system.

9. A computer-readable storage medium containing processor-executable instructions that, when executed on a processor, perform the method of claim 1.

10. A computing system, comprising:

a processor;

memory coupled to the processor, wherein the processor is configured for;

accessing address tables from physical memory of a target computer system;

replicating the address tables on a computing system; and

using data contained in the address tables to derive virtual memory data that was used on the target computer system;

wherein a kernel of the target computer system uses physical memory data of the target computer system for debugging and adds mapping of the address tables into a physical address;

wherein the virtual memory data on the computing system is not identical to virtual memory data on the target computer system.