System and method for supporting non-standard procedure calls

• US 7,512,956 B1
• Filed: 08/14/2003
• Issued: 03/31/2009
• Est. Priority Date: 08/14/2003
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Miller, Sam Arthur, Nicholes, Martin O.
• Primary Examiner(s): Nguyen; Van H
• Application Number:
  US10/640,765
• Time in Patent Office: 2,056 Days
• Field of Search: 719/328, 719/318, 719/322, 719/323, 719/327, 719/310, 719/330, 713/100, 703/23, 703/26, 703/27, 712/226, 711/200, 711/202, 711/203, 345530-574, 709/217, 709/218, 709/219, 709/250
• US Class Current: 719/328
• CPC Class Codes: G06F 9/455 Emulation; Interpretation; Software simulation, e.g. virtualisation or emulation of application or operating system execution engines

Abstract

According to at least one embodiment of the present invention, a system comprises a standard interface for at least one standard procedure. The system further comprises a non-standard interface for at least one non-standard procedure that is not natively supported by the standard interface. The system also comprises an interposer for intercepting procedure calls made to the standard interface and determining whether an intercepted procedure call is for invoking one of the at least one standard procedure or for invoking one of the at least one non-standard procedure. If the intercepted procedure call is for invoking one of the at least one standard procedure the interposer directs the intercepted procedure call to the standard interface, and if the intercepted procedure call is for invoking one of the at least one non-standard procedure the interposer directs the intercepted procedure call to the non-standard interface.

Claims

1. A system comprising:

at least processor;

a standard interface for at least one standard procedure;

a non-standard interface for at least one non-standard procedure that is not natively supported by said standard interface;

an interposer for intercepting procedure calls made to said standard interface and determining whether an intercepted procedure call is for invoking one of said at least one standard procedure or for invoking one of said at least one non-standard procedure, wherein if said intercepted procedure call is for invoking one of said at least one standard procedure said interposer directs said intercepted procedure call to said standard interface and wherein if said intercepted procedure call is for invoking one of said at least one non-standard procedure said interposer directs said intercepted procedure call to said non-standard interface;

an index, comprising less bits when identifying said one of said at least one standard procedure than when identifying said one of said at least one non-standard procedure, included in said intercepted procedure call to identify a procedure to be invoked; and

wherein said interposer determines from said index whether said index identifies said one of said at least one standard procedure or said one of said at least one non-standard procedure.

2. The system of claim 1 wherein said standard interface is a Processor Abstraction Layer (PAL) interface.

3. The system of claim 1 wherein said at least one standard procedure is a standard procedure for an INTEL Architecture (IA)-64 processor.

4. The system of claim 1 wherein said interposer is assigned a vector used for accessing said standard interface for intercepting said procedure calls made to said standard interface.

5. A computer-implemented method comprising:

intercepting a procedure call intended for a first interface that supports standard procedures;

determining from said intercepted procedure call whether said intercepted procedure call is for invoking one of said standard procedures or whether said intercepted procedure call is for invoking a non-standard procedure that is not supported by said first interface;

if determined that said intercepted procedure call is for invoking one of said standard procedures, directing said intercepted procedure call to said first interface; and

if determined that said intercepted procedure call is for invoking said non-standard procedure, directing said intercepted procedure call to a second interface that supports said non-standard procedures; and

analyzing an index value, comprising less bits when identifying said one of said standard procedures than when identifying said non-standard procedure, included in said intercepted procedure call to determine whether said index value identifies said one of said standard procedures or whether said index value identifies said non-standard procedure.

6. The method of claim 5 wherein said intercepting is transparent to a caller initiating said procedure call.

7. The method of claim 5 wherein said first interface comprises a Processor Abstraction Layer (PAL) interface for an INTEL Architecture (IA)-64 processor.

8. The method of claim 5 further comprising:

if determined that said intercepted procedure call is for invoking said non-standard procedure, determining whether said second interface is implemented for supporting said non-standard procedure; and

performing said directing of said intercepted procedure call to said second interface if determined that said second interface is implemented.

9. The method of claim 8 further comprising:

if determined that said intercepted procedure call is for invoking said non-standard procedure and determined that said second interface is not implemented, returning a response to a caller that initiated said intercepted procedure call, said response consistent with a response from said first interface to said intercepted procedure call.

10. A computer-implemented method of obscuring procedure calls, said method comprising:

predefining at least one special index that identifies a non-standard procedure that is not supported by a standard interface, wherein said at least one special index is different than standard indices that identify standard procedures supported by said standard interface;

including an index in a procedure call intended for said standard interface, wherein said index identifies a procedure to be invoked;

intercepting procedure calls intended for said standard interface;

determining whether a special index is included in an intercepted procedure call; and

if determined that said special index is included in said intercepted procedure call, directing said intercepted procedure call to a non-standard interface that supports said non-standard procedure identified by said special index included in said intercepted procedure call; and

wherein said at least one special index comprises more bits than bits included in said standard indices.

11. The method of claim 10 wherein said at least one special index is larger in value than said standard indices.

12. The method of claim 10 further comprising:

if determined that a special index is not included in said intercepted procedure call, directing said intercepted procedure call to said standard interface.

13. A computer-implemented method of obscuring procedure calls, said method comprising:

predefining at least one special index that identifies a non-standard procedure that is not supported by a standard interface, wherein said at least one special index is different than standard indices that identify standard procedures supported by said standard interface;

including an index in a procedure call intended for said standard interface, wherein said index identifies a procedure to be invoked;

intercepting procedure calls intended for said standard interface;

determining whether a special index is included in an intercepted procedure call;

if determined that said special index is included in said intercepted procedure call, directing said intercepted procedure call to a non-standard interface that supports said non-standard procedure identified by said special index included in said intercepted procedure call;

selecting a pseudo-random base number generated by a random number generator;

assigning an offset value for each non-standard procedure for which support is desired; and

including in a procedure call an index equal to a sum of said pseudo-random base number plus a corresponding offset assigned to a desired non-standard procedure for invoking said desired non-standard procedure.

14. A system comprising:

at least one processor;

Processor Abstraction Layer (PAL) interface for supporting standard PAL procedures;

a non-standard interface for accessing at least one non-standard procedure that is not natively supported by said PAL interface; and

an interposer for intercepting procedure calls made to said PAL interface and determining whether an intercepted procedure call is for invoking one of said standard PAL procedures or for invoking one of said at least one non-standard procedure, wherein if said intercepted procedure call is for invoking one of said standard PAL procedures said interposer directs said intercepted procedure call to said PAL interface and wherein if said intercepted procedure call is for invoking one of said at least one non-standard procedure said interposer directs said intercepted procedure call to said non-standard interface;

an index, comprising less bits when identifying said one of said standard PAL procedures than when identifying said one of said at least one non-standard procedure, included in said intercepted procedure call to identify a procedure to be invoked; and

wherein said interposer determines from said index whether said index identifies said one of said standard PAL procedures or said one of said at least one non-standard procedure.

15. The system of claim 14 wherein said standard PAL procedures include at least one procedure for accessing a first cache, and wherein said at least one non-standard procedure includes a procedure for accessing an additional cache that is not supported by said PAL interface.