Method for altering execution of a program, debugger, and computer-readable medium

Patent metadata

Field	Value
Publication number	US-9639343-B2
Application number	US-201414528451-A
Country	US
Kind code	B2
Filing date	Oct 30, 2014
Priority date	Aug 29, 2014
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A method for altering execution of a program on a computer. The program resides in a memory unit that has a logical address space assigned thereto. The method comprises: operating the computer to start executing the program; operating the computer to suspend execution of the program; selecting a patch insertion address within a logical address range of the program, saving the original code residing at the patch insertion address; generating a patch routine; writing a jump instruction to the patch insertion address, thus overwriting said original code, wherein the jump instruction is arranged to instruct the computer to jump to a start address of the patch routine; and operating the computer to resume execution of the program. The patch routine is arranged to prompt the computer to: save a current context of the program; execute a user code; restore the saved context of the program; and execute a surrogate code.

First claim

The invention claimed is:

1. A method for altering execution of a program on a computer, wherein the program resides in a memory unit that has a logical address space assigned to it, and wherein the method comprises:
operating the computer to start executing the program;
operating the computer to suspend execution of the program;
selecting a patch insertion address within a logical address range of the program,
saving original code residing at the patch insertion address;
generating a patch routine comprising user-defined code for modifying a function of the program;
writing a jump instruction to the patch insertion address, thus overwriting said original code, wherein the jump instruction is arranged to instruct the computer to jump to a start address of the patch routine;
compiling only the patch routine without recompiling the entire program; and
operating the computer to resume execution of the program;
wherein the patch routine is arranged to prompt the computer to:
save a current context of the program;
execute the user-defined code;
restore the saved current context of the program; and
execute a surrogate code which is equivalent to said original code, and
wherein the patch insertion address is selected such that said action of operating the computer to resume execution of the program prompts the computer to reach the patch insertion address and, accordingly, to execute the patch routine.

2. The method of claim 1 , wherein generating the patch routine comprises: compiling the patch routine on the basis of the following: a source code of the user-defined code and said original code.

3. The method of claim 1 , comprising: generating the user-defined code by compiling a source code of the user-defined code.

4. The method of claim 1 , comprising: storing the patch routine in pre-allocated program memory.

5. The method of claim 1 , wherein the method comprises:
enabling a user to select the patch insertion address.

6. The method of claim 1 , wherein the method comprises:
enabling a user to define the user-defined code.

7. The method of claim 1 , further comprising:
restoring the original code at the patch insertion address.

8. The method of claim 1 , further comprising providing a user interface for prompting a computer to execute the method in dependence of user input received from a user via the user interface.

9. The method of claim 8 , wherein the user interface comprises a graphical user interface.

10. The method of claim 8 , further comprising storing executable instructions for performing the method on a non-transitory computer-readable medium.

Assignees

• Nistor Mihail-Marian
• Madan Teodor
• Miloiu Dragos
• Nxp Usa Inc

Inventors

• Nistor Mihail-Marian
• Madan Teodor
• Miloiu Dragos

Classifications

• G06F11/3644 Primary

  by instrumenting at runtime · CPC title

• G06F8/68

  Physics · mapped topic

• G06F8/65 Primary

  Updates (security arrangements therefor G06F21/57) · CPC title

• G06F9/48

  Program initiating; Program switching, e.g. by interrupt · CPC title

• G06F9/461

  Saving or restoring of program or task context · CPC title