JPH06131204A - System call function restriction system - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a system call function restriction system, and an object thereof is to provide a system call function restriction system in which the system does not go down due to an incorrect system call access. [Configuration] A system 4 including a plurality of tasks 3 is connected to an operating system 1, and the task 3
A system call entry table 10 that manages a set of usable system calls for each task in the system 4 in a system configured to access any system call 2 in the operating system 1 as needed. Configure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system call function restriction system.

[0002]

When an arbitrary system utilizes an operating system (OS), the OS provides the system with a set of system calls. FIG. 4 is an explanatory diagram of a conventional system call access method. In the figure, 1 is an operating system, 2 is a plurality of system calls stored in the operating system 1, and in the figure, three types A to C are shown.
It can be considered that these system calls 2 are a sequence necessary for each task to perform its processing function and are grouped for each function and are made into a subroutine.

Reference numeral 3 denotes a plurality of tasks, which are provided in a certain system 4. Although two types of task A and task B are shown in the figure, the number of types is not limited to two. In the conventional system of this type, each task 3 can freely access the system call 2 in the OS.

[0004]

The system call 2 described above includes a system call set used by a task for controlling or managing the system 4 and a system call set used by a general task. Examples of the former task include, for example, a restart processing and failure processing task, and examples of the latter task include, for example, a call processing task.

In this case, if a general task carelessly accesses the former system call set, normal system control or management may not be performed, and in the worst case, the system may be down, which may result in reliability. There was a problem that was blocked. The present invention has been made in view of the above problems, and an object of the present invention is to provide a system call function restriction system that does not bring down a system due to an erroneous system call access.

[0006]

FIG. 1 is a block diagram showing the principle of the present invention. The same parts as those in FIG. 4 are designated by the same reference numerals. In the system shown in the figure, a system 4 including a plurality of tasks 3 is connected to an operating system 1, and the task 3 is configured to access an arbitrary system call 2 in the operating system 1 as needed. Configure the system. Reference numeral 10 denotes a system call entry table provided in the system 4 for managing a usable system call set for each task.

[0007]

Each task 3 has the system entry table 10
The OS 1 can be accessed through the system entry table 10. Only system calls that each task may access are registered in the system entry table 10. Therefore, each task 3 cannot access a system call that is not registered in the system call entry table 10.

FIG. 2 is an explanatory view of the operation of the present invention. From each task 3, the system call 2 of the access route shown by the solid line
Only the system call 2 of the access route shown by the broken line cannot be accessed. Therefore, according to the present invention, it is possible to provide a system call function restriction system in which the system does not go down due to an incorrect system call access.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 3 is a configuration block diagram showing an embodiment of the present invention. The same parts as those in FIG. 1 are designated by the same reference numerals. In the figure, reference numeral 4 is a system in which a plurality of tasks 3 and an entry table pointer 3a associated therewith are provided. Reference numeral 10 is a system call entry table characterizing the present invention, and a plurality of system call entry tables are provided. In the illustrated example, table A and table B are shown as the system call entry table 10, but the present invention is not limited to this, and an arbitrary number of system call entry tables 10 can be provided. Further, the number of tasks provided in the system 4 is not limited to three, as shown in the figure, from # 1 to # 3, and any number of tasks can be provided.

This system call entry table 10
Can be provided for each task, but as shown in the figure, can also be provided corresponding to a task set of the same type.
For example, in the embodiment shown in the figure, the entry table A corresponds to the task # 1, and the entry table B corresponds to the tasks # 2 and # 3. The operation of the system configured as described above will be described below.

Now, assume that task # 1 is executed. The entry pointer table 3a accesses the system call entry table A. Then, when the task is executed, each system call 2 in the OS 1 is accessed via this system call entry table A.

As described above, the system call entry table 10 contains only the system calls necessary for executing the corresponding task. That is, in the system call entry table 10, only the necessary system call 2 out of all the n system calls included in the OS 1 is registered, and therefore, the unused system calls are in a so-called missing form. Has become. In this way, when executing the task # 1, only the system call 2 registered in the system call entry table A is accessed. Therefore, by mistake, another system call 2
There is no danger of being accessed.

For example, the system call entry table 10 is divided into a set of system calls used by a task for controlling or managing the system and a set of system calls used by another general task and registered. In this case, for example, there is no possibility that a call processing task, which is a general task, will access the system call for the restart processing task for system control / management.

[0014]

As described above in detail, according to the present invention, it is possible to provide a system call function restriction system in which the system does not go down due to an incorrect system call access.

[Brief description of drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is an explanatory view of the operation of the present invention.

FIG. 3 is a configuration block diagram showing an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a conventional system call access method.

[Explanation of symbols]

 1 Operating system 2 System call 3 Task 4 System 10 System call entry table

Claims (3)

[Claims] 1. A system (4) comprising a plurality of tasks (3) is connected to an operating system (1), and the task (3) executes an arbitrary system call (2) in the operating system (1). In a system configured to be accessed as needed, a system call entry table (10) for managing a set of usable system calls for each task is provided in the system (4). Function limitation system. 2. The types of system calls that can be used by the task (3) are limited to those registered in a specific system call entry table (10), so that a system call set of another type is mistakenly accessed. The system call function restriction system according to claim 1, wherein the system call function restriction system is disabled. 3. The system call function limiting system according to claim 1, wherein the system call entry table (10) is provided for a task in a certain unit.