Memory protection unit, memory protection method, and computer-readable record medium in which memory protection program is recorded
First Claim
1. A memory protection unit, comprising:
- a memory which includes at least one memory area that is used by at least one subroutine, and in which a writing attribute is set for every memory area, the writing attribute representing a writing permission or a writing prohibition;
a subroutine choosing means for accepting a processing request, and choosing a subroutine which executes the processing request;
a memory-area specifying means for specifying a memory area which is used by the subroutine that is chosen by the subroutine choosing means; and
a subroutine calling means for setting, to the writing permission, the writing attribute of the memory area which is specified by the memory-area specifying means, thereafter calling and executing the subroutine that is chosen by the subroutine choosing means, and setting, to the writing prohibition, the writing attribute of the memory area which is set to the writing permission after completing the execution of the subroutine.
1 Assignment
0 Petitions
Accused Products
Abstract
A memory protection unit, a memory protection method and a computer-readable record medium in which a memory protection program is recorded is provided which are capable of preventing a memory from being improperly rewritten by a malfunction in a subroutine. This memory protection unit includes: a memory which has at least one memory area that is used by at least one subroutine, and in which a writing attribute that shows a writing permission or a writing prohibition can be set for every memory area; a subroutine choice section which chooses a subroutine that executes a processing request; a memory-area specification section which specifies a memory area that is used by the subroutine; and a subroutine calling section which sets, to the writing permission, the writing attribute of the specified memory area, calls the chosen subroutine, and sets, to the writing prohibition, the writing attribute of the memory area after completing the execution of the subroutine.
-
Citations
11 Claims
-
1. A memory protection unit, comprising:
-
a memory which includes at least one memory area that is used by at least one subroutine, and in which a writing attribute is set for every memory area, the writing attribute representing a writing permission or a writing prohibition;
a subroutine choosing means for accepting a processing request, and choosing a subroutine which executes the processing request;
a memory-area specifying means for specifying a memory area which is used by the subroutine that is chosen by the subroutine choosing means; and
a subroutine calling means for setting, to the writing permission, the writing attribute of the memory area which is specified by the memory-area specifying means, thereafter calling and executing the subroutine that is chosen by the subroutine choosing means, and setting, to the writing prohibition, the writing attribute of the memory area which is set to the writing permission after completing the execution of the subroutine. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A memory protection method for managing writing in a memory including at least one memory area that is used by at least one subroutine by allowing the memory area to be settable with a writing attribute representing a writing permission or a writing prohibition, comprising:
-
a subroutine choosing step for accepting a processing request, and choosing a subroutine which executes the processing request;
a memory-area specifying step for specifying a memory area which is used by the subroutine that is chosen in the subroutine choosing step; and
a subroutine calling step for setting, to the writing permission, the writing attribute of the memory area which is specified in the memory-area specifying step, thereafter calling and executing the subroutine that is chosen in the subroutine choosing step, and setting, to the writing prohibition, the writing attribute of the memory area which is set to the writing permission after completing the execution of the subroutine.
-
-
11. A computer-readable record medium recorded with a memory protection program for managing writing in a memory including at least one memory area that is used by at least one subroutine by allowing the memory area to be settable with a writing attribute representing a writing permission or a writing prohibition;
- the memory protection program allowing a computer to function as;
a subroutine choosing means for accepting a processing request, and choosing a subroutine which executes the processing request;
a memory-area specifying means for specifying a memory area which is used by the subroutine that is chosen by the subroutine choosing means; and
a subroutine calling means for setting, to the writing permission, the writing attribute of the memory area which is specified by the memory-area specifying means, thereafter calling and executing the subroutine that is chosen by the subroutine choosing means, and setting, to the writing prohibition, the writing attribute of the memory area which is set to the writing permission after completing the execution of the subroutine.
- the memory protection program allowing a computer to function as;
Specification