JPH05189255A - Program runaway detection method - Google Patents

Abstract

PURPOSE:To detect whether or not a program runs away by judging whether or not an address which is executed at present is included in a memory area obtained from the module number of a module which is executed at present and a corresponding table at every prescribed time. CONSTITUTION:In a step S1, the address during execution is read, and the module number during execution is read in a step S2. In a step S3, an execution start address and the size of the module are retrieved from the module size corresponding table. In a step S4, the address during execution is judged to be within a range or not as the retrieval result of size. When the address during execution is within the range as the result of the judgment, a system advances from the YES-side of the step 4 to a step 5 and the system is set to be normal. When the address during execution is not within the range in the step S4, the system advances from the NO-side of the step S4 to a step S6 and the program of a computer system is judged to be abnormal (during runaway).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a program runaway detection method used in a computer system or the like.

[0002]

2. Description of the Related Art A conventional computer system has no mechanism for detecting runaway of a program.

[0003]

Since the above-mentioned conventional computer system does not have a mechanism for detecting a program runaway, it is fatal that the system is stopped due to execution of an abnormal address or the system becomes unresponsive. And the runaway of the program cannot be detected until it falls into the unrecoverable state.

The present invention solves such a conventional problem and is excellent in that it can detect a program runaway and recover the system state before the system falls into a fatal and unrecoverable state. It is to provide a program runaway detection method.

[0005]

In order to achieve the above-mentioned object, the present invention adds a unique module number to each module and stores the module number of the module currently being executed, the module number and the module. Has a correspondence table for searching the correspondence between the start address of the area occupied in the memory and the size of the area, and the address currently being executed is obtained at regular intervals from the module number of the module currently being executed and the above correspondence table. It is determined whether or not it is included in the memory area and whether or not the program is out of control.

[0006]

Therefore, according to the present invention, it is possible to detect whether or not the program is in a runaway state at regular time intervals, so that the failure recovery processing can be performed before the program is in a fatal state. It has the effect of being able to.

[0007]

1 is a block diagram of a computer system applied to a first embodiment of the present invention. In FIG. 2, 21 is a central processing unit (hereinafter referred to as CPU), and 22 is a CP.
U21 is a general-purpose register (hereinafter referred to as R ₁ , R ₂ , R ₃ ), 23 is a program counter in the CPU 21, 24 is a stack area, and 25 is a memory area. Reference numeral 26 is a correspondence table of the module number of the module group 27 included in the memory area 25, the start address of the memory area in which the modules are stored, and the area size.

Reference numeral 12 in FIG. 3 is a diagram showing a specific example of the correspondence in FIG. 2, showing a module number, a module start address, and a module size correspondence table. Reference numeral 13 in FIG. 4 indicates a running module number storage area.

FIG. 5 and FIG. 6 are flow charts of a program in the first embodiment of the present invention. In FIG. 5, reference numeral 31 is a module for determining whether or not a runaway is occurring, and 32 in FIG. 6 is a module for determining whether or not the module 31 is under a runaway.

Next, the operation of the first embodiment will be described. In the first embodiment, FIG. 1 is a flow chart for explaining the operation principle of the first embodiment. First, the address being executed is read in step S1 in FIG. The module number 13 being executed shown in 4 is read out, and step S3
Then, the execution start address and the module size are searched from the module number, module start address, and module size correspondence table 12 shown in FIG.

As a result of this size search, it is determined in step S4 whether or not the address being executed is within the range. If the result of this determination is that the address being executed is within the range, the operation proceeds from the YES side of step S4 to step S5,
Normal. If the address being executed is not within the range in step S4, the NO side of step S4 is followed by step S
Proceeding to step 6, it is determined that the computer system program is abnormal.

Next, the first embodiment will be described more specifically with reference to FIGS. In FIG. 5, step S11
The module called by another module in step S12 stores the module number of the calling source in the running module number storage area in the stack 24, and stores its own module number in the execution module number storage area in step S12.
After that, the original processing is performed in step S13.

In step S14, an interrupt process for detecting runaway is performed at regular intervals throughout the portion where the original process is performed, and after the original process is completed, the module of the calling module saved in the stack. The number is stored in the executing module number storage area, and control is returned to the calling module in step S15.

In the interrupt process for detecting runaway shown in FIG. 6, the address currently being executed is obtained in step S21, read out to the general-purpose register R ₁ , and in step S22, the value of the module number storage area being executed and the above correspondence. The program start address obtained from Table 26 is substituted into the register R _2, and the size of the program area is substituted into R ₃ .

Thereafter, in step S23, if the value obtained by subtracting the value of the register R ₂ from the value of the register R ₁ is a negative value or is greater than or equal to the register R _3, it is determined that the program is out of control, The process branches from the NO side of step S23 to perform the failure recovery process, and otherwise, exits from the YES side of step S23 and ends the interrupt process.
As described above, according to the above-described embodiment, since it is possible to detect that the program is out of control and is executing an illegal address at regular intervals, it is possible to detect the out of control of the program before it falls into a fatal state. Therefore, there is an advantage that the failure recovery processing and the like can be performed.

[0016]

As is apparent from the above embodiment, the present invention is obtained from a correspondence table for searching the correspondence between the module number, the start address of the area occupied by the module in the memory, and the size of the area. In the memory area, it is determined whether or not the address currently being executed is included in the module number of the module currently being executed at regular intervals, and the program is running out of control and executing an abnormal address. Since it is possible to detect such a situation, it is possible to detect runaway of the program before the program falls into a fatal state. Therefore, it is possible to execute the failure recovery processing.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining the operation principle of a program runaway detection method according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a computer system to which the first embodiment of the present invention is applied.

FIG. 3 is an explanatory diagram showing a module number, a module start address, and a module size correspondence table applied to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a module number storage area under execution applied to the first embodiment of the present invention.

FIG. 5 is a flowchart for a runaway determination module for explaining the first embodiment of the present invention.

FIG. 6 is a flow chart for a runaway determination module for explaining the first embodiment of the present invention.

[Explanation of symbols]

11 Runaway Judgment Routine 12 Module Number, Module Start Address, Module Size Correspondence Table 13 Running Module Number Storage Area 21 CPU 22 General-purpose Register 23 Program Counter 24 Stack 25 Memory 26 Module Number, Module Start Address, Module Size Correspondence Diagram 27 Running Module number storage area 28 Module group 31 Flow chart of runaway judgment module 32 Flow chart of runaway judgment module

Claims (1)

[Claims] 1. A start address and an area of an area on the memory occupied by each module corresponding to the module number by adding a module number uniquely determined to each module in the program and storing the module number of the module currently being executed. The size of is stored in the correspondence table, and if the address currently being executed is not within the range of the module number currently being executed and the address obtained from the above correspondence table at regular intervals, the program is running out of control. A program runaway detection method characterized by determining that