JPH05204764A - Ring protecting system for memory protect - Google Patents

Abstract

PURPOSE:To improve the processing efficiency of a computer and to improve the performance of the computer by preventing dispatch from being inhibited by providing a register to store the current value in a ring mode. CONSTITUTION:Concerning the ring protecting system for memory protect to execute a program shown by the ring mode of protect information applied to the program and the current value in this ring mode, a control memory 1 is provided to store the current value for each ring mode, general-purpose register 3 to store the ring mode of the current value showing the execution of the program among the ring modes stored in this control memory 1, and means 5 is provided to save the current value stored in the general-purpose register into the control memory when changing the ring mode and to load the current value of the ring mode stored in the control memory to be changed into the general-purpose register.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ring protection system for storage protection which gives a ring mode as protection information to each program, determines the priority of the program by the ring mode, and permits access from the program. Of these, in particular, the present invention relates to a storage protection ring protection system that improves the processing efficiency of a computer by providing a general-purpose register that stores the current value of the changed ring mode when the ring mode is changed.

[0002]

2. Description of the Related Art Generally, there is a ring protection system as a storage protection function for the purpose of improving the reliability of a storage device and preventing the information in the main storage device from being destroyed.

In the above ring protection method, protection information called a ring number is given to a program, the priority of the program is determined based on the size of the ring number, and access from the program is permitted. A computer equipped with the above ring protection method is generally called from a different test context in a routine executed in a kernel mode of a program with a small ring number (hereinafter referred to as a ring mode), so trace information for tracing the execution process of the program Debugging is performed by. When the debug based on the trace information is executed, a large-scale task-shared memory space is required to prevent the control from being transferred and the data from being destroyed. Therefore, it is not easy to prevent the overhead from increasing when the task-shared memory is frequently referenced during execution of the trace.

[0004]

By the way, conventionally, if the memory of the task sharing is frequently referred to and updated during the execution of the trace, the overhead increases and the processing efficiency of the computer is lowered.

Further, when an asynchronous interrupt or the like occurs, the task C is held while the trace information is held in the register.
It has been necessary to give a right to use the PU to prohibit the dispatch of executing the execution unit of the task by the CPU, which causes a problem in the processing of the computer.

The present invention has been made to solve such a conventional problem, and an object thereof is to improve the processing efficiency of a computer by providing a register for storing the current value of the ring mode. The purpose of the present invention is to provide a ring protection method of storage protection that prevents dispatch inhibition and improves computer performance.

[0007]

In order to achieve the above object, the present invention provides a ring protection system of storage protection for executing a ring mode of protection information given to a program and a program indicated by a current value in the ring mode. In, a control memory for storing a current value for each ring mode, a general-purpose register for storing a current value ring mode indicating execution of a program among the ring modes stored in the control memory, and the ring mode are A means for saving the value of the register stored in the general-purpose register when it is changed to the control memory, and loading the value of the changed ring mode register stored in the control memory to the general-purpose register, The summary is that

[0008]

With the above configuration, when the ring mode of the protection information given to the program is changed, the current value stored in the general-purpose register is saved in the control memory for storing the current value for each ring mode. Then, since the changed ring mode current value stored in the control memory is loaded into the general-purpose register, the time for referring to the current value becomes faster, and the processing efficiency of the computer can be improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of a ring protection system for storage protection according to the present invention.

In FIG. 1, a control memory 1 is used as a work area by a firmware 5 which will be described later and stores a ring mode which is protection information of a program. The ring mode is stored from ring 0 to ring n, and the value in each ring is the current value indicating the program that executes the process in the ring.

The general-purpose register 3 stores the current current value, and when the ring mode is changed, it stores the changed current value of the ring mode.

When the ring mode is changed, the firmware 5 saves the current value stored in the general-purpose register 3 in the control memory 1 and loads the changed current value in the ring mode into the general-purpose register 3. For example, when the ring mode is changed from ring 0 to ring 1, the firmware 5 saves the current value stored in the general-purpose register 3 to the control memory by ST (R _x , R ₀ ) and stores it in the control memory 1. LOA the current value in ring 1
The general purpose register 3 is loaded by D (M ₁ , R _x ).

Next, the ring protection system will be described with reference to FIG.

The kernel mode, which is the highest mode, is an operating system (hereinafter referred to as OS),
The current value C points to the fifth program. The current value C of the ring 1 of the management program, which is the next mode of the kernel mode, indicates the fourth program. Current value C of subsystem 2 which is the next mode of ring 1
Indicates the program following program A. The current value C of the user mode of the user program which is the next mode of the ring 1 indicates the program next to the program D.

Although the ring mode, the ring 2 and the user mode program can be accessed from the kernel mode which is the highest mode, the user mode program, on the contrary, can be accessed in the upper ring 2, ring 1 and the kernel mode. Cannot access each program.

Next, the operation of the present embodiment will be described with reference to the diagram for explaining the operation shown in FIG. 3 and the flow chart in FIG.

First, when the ring mode is changed from i to j, the firmware 5 sets the value (current value) in the ring i stored in the general-purpose register 3 to ST (R _x , M
_i ) value in ring i of control memory 1 (current value)
(The arrow 11 in the figure, ST1).

When the firmware 5 saves the value (current value) in the ring i, the firmware 5 loads the value (current value) in the ring j of the control memory 1 into the general-purpose register 3 by LOAD (M _j , R _x ) (see FIG. Middle arrow 13, ST13).

As a result, since the changed value (current value) in the ring mode can be confirmed by referring to the general-purpose register 3, the ring mode can be processed at a higher speed than in the conventional case.

FIG. 5 shows a system configuration diagram in which the ring protection system of the memory protection of the present invention is applied when the trace information of the module is recorded.

First, the modules M1, M2 of the ring i are
At the head of M3, the value stored in the general-purpose register 11 is written in the trace information of ring i. Since the write destination information is stored in the general-purpose register 11, the general-purpose register 1
Increment the value of 1.

When the ring mode is changed from i to j, the firmware 13 saves the value of the ring i stored in the general-purpose register 11 into the control memory 15 and the control memory 15
Load the value in ring j into general register 11.

Next, at the head of the modules M4 and M5 of the ring j, the trace information of the ring j is written from the value of the general register 11, and the information of the write destination is the general register 1.
Since it is stored in 1, the value of the general register 11 is incremented.

When the ring mode is changed from j to i, the firmware 13 saves the value of the ring j stored in the general-purpose register 11 into the control memory 15, and the control memory 15
Load the value in ring i into general register 11.

[0026]

As described above, according to the present invention, since the changed ring mode current value is stored in the general-purpose register, the processing efficiency of the computer is improved and the dispatch inhibition is prevented to improve the performance of the computer. Can be improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a ring protection system for storage protection of the present invention.

FIG. 2 is a diagram showing a ring protection system.

FIG. 3 is a diagram showing an operation of the present invention.

FIG. 4 is a flowchart showing the operation of the present invention.

FIG. 5 is a diagram showing an application example of the present invention.

[Explanation of symbols]

 1,15 Control memory 3,11 General-purpose register 5,13 Firmware

Claims (1)

[Claims] 1. A ring mode of protection information given to a program, and a ring protection system of memory protection for executing a program indicated by a current value in the ring mode, wherein a control memory for storing a current value for each ring mode is provided. Of the ring modes stored in this control memory, a general-purpose register that stores the ring mode of the current value that indicates the execution of the program, and a current value that is stored in the general-purpose register when the ring mode is changed, A ring protection system for storage protection, comprising: means for saving the current value of the changed ring mode stored in the control memory into the general-purpose register, the means being for saving.