JPH07152653A - Data processor - Google Patents

Abstract

PURPOSE:To actualize storage protection for a virtual storage area matching a program without requiring any troublesome process when plural kinds of programs run in the same space as to the data processor which protects the virtual storage area by holding storage protection information on the virtual storage area in an entry of an address conversion table. CONSTITUTION:Plural address conversion tables 2 with which the same address converting process is performed are prepared according to the kinds of programs which run in the same space and storage protection information matched with the kinds of the programs is developed in entries of those address conversion tables 2; and the data processor is equipped with a selection part 5 which selects an address conversion table matching the kind of a running program among those prepared address conversion tables 2 as an effective address conversion table 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processing device having a structure for protecting a virtual storage area by holding storage protection information of the virtual storage area in an entry of an address translation table, and more particularly, to a data processing apparatus in the same space. The present invention relates to a data processing device that realizes storage protection of a virtual storage area suitable for a program without requiring complicated processing when different types of programs run.

[0002]

2. Description of the Related Art In a data processing device using a virtual storage control method that uses an address translation table composed of a segment table / page table, usually, a configuration is adopted in which the access right information of the virtual storage area is held in the entry of the page table. By adopting a configuration in which the memory protection of the virtual storage area is realized by inspecting the presence or absence of the access right of the virtual storage area according to the access right information during the address conversion processing by hardware.

When such a storage protection method for a virtual storage area is adopted, it may be desired to change the storage protection mode depending on the type of program. For example, when a user program and a system program run in the same space, access to the system program may be permitted but access to the user program may not be permitted.

In response to such a request, conventionally, a method has been adopted in which the memory protection information in the entry of the page table is replaced with one suitable for the program every time the running program is switched.

[0005]

However, according to such a conventional technique, since the memory protection information in the entry of the page table has to be replaced every time the running program is switched, a complicated process is required. There was a problem of being forced.

The present invention has been made in view of the above circumstances, and exists when a configuration is adopted in which the virtual storage area is protected by holding the storage protection information of the virtual storage area in the entry of the address translation table. An object of the present invention is to provide a new data processing device that realizes storage protection of a virtual storage area suitable for a program without requiring complicated processing when different types of programs run in the same space.

[0007]

FIG. 1 shows the principle configuration of the present invention. In the figure, reference numeral 1 is a data processing apparatus equipped with the present invention.

Reference numeral 2 is an address conversion table, for example, 2 according to the type of program running in the same space.
A plurality of such items are provided, each of which develops storage protection information (access right information) according to the type of program in the entry. These address conversion tables 2 execute the same address conversion process such as converting the same virtual address into the same real address.
These address conversion tables 2 may be configured with a plurality of stages having a common top table.

Reference numeral 3 is a page-divided real memory indicated by the address conversion table 2. An address conversion table management unit 4 executes management of the address conversion table 2.

Reference numeral 5 denotes a selection unit provided in the address conversion table management unit 4, which selects from among a plurality of prepared address conversion tables 2 those which are suitable for the type of running program as valid ones. This selection unit 5
When these address conversion tables 2 are configured in a multi-stage table configuration in which the highest table is common, the effective address conversion table 2 is selected by switching the pointer pointed to by the highest table. To go.

[0011]

According to the present invention, for example, when the user program and the system program run in the same space, the address conversion table 2 for the user program and the address conversion table 2 for the system program that execute the same address conversion process. And prepares the access right information for the user program in the entry of the address conversion table 2 for the user program, and the access for the system program in the entry of the address conversion table 2 for the system program. It develops rights information.

When adopting this configuration, when the type of the running program is switched, the selecting section 5 selects one of the plurality of prepared address conversion tables 2 which is suitable for the type of the running program. Address conversion table 2. According to this selection process,
Access right information suitable for the running program is set.

As described above, according to the present invention, when different types of programs run in the same space, the memory protection of the virtual storage area suitable for the programs is realized without requiring complicated processing. become able to.

[0014]

EXAMPLES The present invention will be described in detail below with reference to examples. FIG. 2 illustrates a mechanism configuration provided for executing the virtual memory control process of the present invention.

In the figure, 4 is an address conversion table management unit also shown in FIG. 1, which manages the address conversion table 2. In order to execute this processing, an address conversion table switching processing module 40 and , A real page allocation processing module 41 and a real page allocation cancellation processing module 42.

A paging controller 6 executes a replacement process for effectively using the real memory 3 divided into pages, and in order to execute this process, a page-in request processing module 60 and a page-in request processing module 60 are provided. , Page-in completion processing module 61, page-out request processing module 62, page-out completion processing module 6
3 and 3.

Reference numeral 7 denotes a real memory management unit, which manages the real memory 3 divided into pages, and a real page acquisition processing module 70 and a real page robbing processing module 71 for executing this processing. Equipped with.

As described with reference to FIG. 1, in the present invention, when different kinds of programs run in the same space, a plurality of address conversion tables 2 for executing the same address conversion process according to the kinds of the programs. Is prepared, and the storage protection information according to the type of program is expanded in the entries of these address conversion tables 2.

For example, when the user program and the system program run in the same space, as shown in FIG. 3, the segment table 21a for the user program pointed to from the starting point table 20 and the segment table 21a are pointed to from this segment table 21a. The user program address conversion table 2 including the user program page table 22a is prepared, and the system program segment table 21b pointed from the starting point table 20 and the system program pointed to by the segment table 21b are prepared. The address translation table 2 for the system program, which is composed of the page table 22b for the same address, is prepared. It converted to the same real address the dress)
Configure to run.

Then, in the entry of the page table 22a for the user program, storage protection information indicating whether or not the user program can access is expanded, and an entry of the page table 22b for the system program is made. The storage protection information indicating whether or not the system program can be accessed is developed therein.

In order for the address conversion table 2 for the user program and the address conversion table 2 for the system program to execute the same address conversion processing, the two page tables 22a and 22b have the same actual addresses. It is necessary to point to a page in memory 3. next,
The pointer setting process for the page tables 22a and 22b will be described with reference to FIG.

At the time of accessing a certain virtual page, a page fault occurs because the real page does not exist, and
When the contents of the target virtual page are not saved in the secondary storage, that is, when a new real page needs to be allocated, as shown in (4) in the figure, the real page acquisition processing module 70 When the control is passed to the step S1, the real page acquisition process is performed as shown in (5) in the figure, and subsequently, the instruction in which the page fault has occurred is re-executed as shown in (8) in the figure.

During this real page acquisition processing, as shown in (6) in the figure, the real page allocation processing module 41
As a result, the real page allocation process is performed on the entry of the page table 22a, 22b corresponding to the target virtual page, as indicated by (7) in the figure. That is, as shown in FIG. 3, for example, the page table 22
The entry β of a and the entry β ′ of the page table 22b are set so as to point to the same newly allocated real page.

On the other hand, when a certain virtual page is accessed, a page fault occurs due to the nonexistence of a real page, and the contents of the target virtual page are saved in the secondary storage. As shown in (9),
After the control is passed to the page-in request processing module 60, as shown in (10) in the figure, the information on the secondary storage is read into the real page, and after the reading process is completed, it is shown in (11) in the figure. As described above, the control is passed to the page-in completion processing module 61.

At this time, as shown by (12) in the figure, control is passed to the real page allocation processing module 41, and the entry in the page tables 22a, 22b corresponding to the virtual page of interest is controlled. As shown in (7) of (3), real page allocation processing is performed. That is, as shown in FIG.
For example, the entry β of the page table 22a and the entry β ′ of the page table 22b are set so as to point to the same real page read from the secondary storage.

Next, the page-in completion processing module 6
The control returns to 1, and the instruction in which the page fault has occurred is re-executed as indicated by (13) in the figure. On the other hand, when the real pages assigned to the page tables 22a and 22b are targeted for page-out by the real-page robbing processing module 71, the page-out request processing module 62 controls as shown in (14) in the figure. From this module, as shown in (15) in the figure, control is passed to the real page deallocation processing module 42 to carry out real page deallocation processing as shown in (16) in the figure. . That is, as shown in FIG. 3, for example, the real memory allocation is released from the entry α of the page table 22a and the entry α ′ of the page table 22b that point to the same real memory.

Then, the control is returned to the page-out request processing module 62, and as shown in (17) in the figure, the information held in the real memory is written to the secondary storage, and after this writing processing is completed. As shown in (18) in the figure, control is passed to the page-out completion processing module 63, and as shown in (19) in the figure, the real page robbing processing module 71
Return control to.

In this way, the address conversion table 2 for the user program, which is composed of the origin table 20 / segment table 21a / page table 22a
Then, the address conversion table 2 for the system program composed of the starting point table 20 / segment table 21b / page table 22b performs the same address conversion process.

Since the page table 22a for the user program and the page table 22b for the system program are separately provided, the user program can access the entry of the page table 22a for the user program. There is a configuration in which access right information indicating whether or not there is an access right information is expanded and the access right information indicating whether or not the system program can be accessed is expanded in the entry of the page table 22b for the system program. Can be taken.

Next, the storage protection processing of the virtual storage area realized by the present invention will be described in detail according to the embodiment shown in FIG. Here, in FIG. 4, 100 is a traveling space,
200 is a user program for traveling in the traveling space 100,
Reference numeral 300 is a system program for traveling in the traveling space 100, and 400 is a dispatcher.

In the embodiment configured as described above, when the user program 200 transfers control to the system program 300 via the dispatcher 400, the address conversion table switching processing module 40 of the address conversion table management unit 4 By receiving the program switching display from the dispatcher 400 and switching the pointer of the starting point table 20, the address conversion table 2 for the system program composed of the starting point table 20 / segment table 21b / page table 22b is selected. As a result, the access right information peculiar to the system program 300 becomes valid, and the storage protection for the virtual storage area is achieved.

On the other hand, when the system program 300 transfers control to the user program 200 via the dispatcher 400, the address translation table switching processing module 40 of the address translation table management unit 4 receives the program switching display from the dispatcher 400. Then, by switching the pointer of the starting point table 20, the address conversion table 2 for the user program, which is composed of the starting point table 20, the segment table 21a, and the page table 22a, is selected. The information becomes valid, and storage protection is achieved for the virtual storage area.

That is, when the dispatcher 400 switches the program, control is passed to the address conversion table switching processing module 40 as shown in (1) of FIG.
As indicated by (2) in FIG. 2, for example, 0 switches the point destination of the starting point table 20 from the segment table 21a to the segment table 21b, thereby executing the switching process of the address conversion table 2, The control is returned to the dispatcher 400 as indicated by (3) in FIG.

[0034]

As described above, according to the present invention,
When different kinds of programs run in the same space, it is possible to realize storage protection of a virtual storage area suitable for the program simply by performing a simple operation such as switching a pointer.

[Brief description of drawings]

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

FIG. 2 is a structural example of a mechanism for realizing the present invention.

FIG. 3 is an example of an address conversion table.

FIG. 4 is an example of the present invention.

[Explanation of symbols]

 1 data processor 2 address conversion table 3 real memory 4 address conversion table management unit 5 selection unit

Claims (2)

[Claims] 1. An address translation table (2) for executing a translation process from a virtual address to a real address is provided, and storage protection information of a virtual storage area is held in an entry of the address translation table (2). In a data processing device that protects a virtual storage area, a plurality of address conversion tables (2) that execute the same address conversion process are prepared according to the type of program running in the same space, and the address conversion table ( In the entry of 2), the structure that expands the memory protection information according to the type of program is adopted, and among the multiple address translation tables (2) prepared, the one that matches the type of running program is effective. A data processing device characterized by comprising a selection unit (5) for selecting as a special address conversion table (2). 2. The data processing device according to claim 1, wherein a plurality of prepared address conversion tables (2) are constituted by a plurality of stages of table configuration having a common topmost table, and a selection unit (5). ) Is a data processing device characterized by performing processing so as to select a valid address conversion table (2) by switching the pointers pointed to by this topmost table.