JPH03132845A - Preventing system for breakage of memory cell in shared memory pool - Google Patents

Abstract

PURPOSE:To prevent the breakage of contents of a memory cell by comparing the access right of a memory cell with the access right of a program when an access is given to the memory cell and producing an address fault to inhibit the access to the memory cell when no access right is recognized. CONSTITUTION:A memory cell control mechanism 7 controls a shared memory pool 1 for each memory cell 2 to segment and return the cells 2 and at the same time retrieves an address conversion table 5 to store the access keys 4 and 8 of the cell 2 at the position of an access key table 3 pointed by a pointer at segmentation of the cell 2. When an access request is received to the cell 2, the keys 4 and 8 showing the access right of the cell 2 are compared with the program keys 9 and 12 showing the access rights of the programs 10 and 11 of an access requester. Then an address fault is produced when no access right is confirmed. Thus it is possible to such a case where the contents of the cell 2 are broken with the illegal use of the cell 2 via a program having no access right.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for preventing memory cell destruction in a shared memory pool, and in particular, a method for dividing the shared memory pool into memory cells and managing the shared memory in a computer system. A method for preventing memory cell destruction in a shared memory pool when it is desired to prevent the contents of memory cells from being destroyed due to unauthorized use of memory cells in a shared memory management method that extracts and returns shared memory for each program to be used on a memory cell basis [Conventional method] [Technology] Conventionally, in a shared memory management method in which a shared memory pool in a computer system is divided into memory cells and managed, and the program that uses the shared memory allocates and returns the shared memory in units of memory cells, it is not possible to even have an address. Any program could access the memory cells in the shared memory pool.

[Problem to be solved by the invention]

In the conventional shared memory management method described above, any program can access memory cells in the shared memory pool as long as it has an address, so if a bug in a program destroys the contents of a memory cell, Another drawback is that other programs that were using the memory cell whose contents have been destroyed may run out of control, and the cause of the trouble cannot be determined because it is often impossible to identify the program that destroyed the contents of the memory cell.

In view of the above-mentioned points, an object of the present invention is to make it possible to divide a shared memory pool into memory cells and manage them, and define access rights for each memory cell when cutting out a program in each memory cell. When an access request is made, the access key indicating the access right to the memory cell is compared with the program key indicating the access right held by the accessing program, and if the access right is not granted, an address fault is generated to determine the access right. To provide a method for preventing destruction of memory cells in a shared memory pool, which prevents the contents of memory cells from being destroyed due to unauthorized use of the memory cells by a program with no program.

[Means to solve the problem]

The method for preventing memory cell destruction in a shared memory pool of the present invention is a shared memory management method in which a shared memory pool placed in a virtual space is divided into memory cells and managed in a computer system that employs a virtual memory method. , an access key table storing access keys indicating access rights to memory cells of the shared memory pool corresponding to memory cells of the shared memory pool, and an access key table for converting addresses from virtual space addresses to real space addresses. An address translation table that stores address translation information and a pointer to the access key of the access key table, and manages the shared memory pool in units of memory cells to extract and return memory cells, and extracts and returns memory cells. a memory cell management mechanism that searches the address conversion table and stores the access key of the memory cell at the location of the access key table indicated by the pointer; Address conversion is performed from a virtual space address to a real space address using an address conversion table, and the access key is referenced in the access key table by following the pointer, and the access right is compared with the program key indicating the access right of the program. It has an address translation mechanism that generates an address fault when it is not recognized.

[Effect]

In the method for preventing memory cell destruction in a shared memory pool of the present invention, an access key table stores access keys indicating access rights to memory cells in the shared memory pool corresponding to memory cells in the shared memory pool, and an address conversion table stores access keys indicating access rights to memory cells in the shared memory pool. stores address conversion information for converting addresses from virtual space addresses to real space addresses, and stores pointers to access keys in the access key table, and the memory cell management mechanism manages the shared memory pool in units of memory cells. At the same time, when the memory cell is extracted, the address conversion table is searched and the access key of the memory cell is stored in the access key table position indicated by the pointer, and the address conversion mechanism is used for shared use by the program. A program key that converts an address from a virtual space address to a real space address using an address conversion table when requesting access to a memory cell in a memory pool, and also refers to the access key in the access key table by following the pointer and indicating the access right of the program. An address fault occurs when the access right is not granted.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a method for preventing memory cell destruction in a shared memory pool according to an embodiment of the present invention. A shared memory pool 1 is placed on top of the main memory and is managed by being divided into a plurality of memory cells 2, an access key table 3 stores access keys 4 corresponding to the plurality of memory cells 2, and a virtual An address conversion table 5 that stores address conversion information for converting a space address to a real space address and also includes a pointer to the access key 4 of the access key table 3 corresponding to the virtual space address, and an address conversion table when accessing memory. 5, an address translation mechanism 6 realized by hardware that performs address translation from a virtual space address to a real space address and manages access rights, and a shared memory pool 1 divided into a plurality of memory cells 2. A memory cell management mechanism 7 realized by software that manages and allocates and returns memory cells 2 according to memory reservation/release requests, and access defined for memory cells 2 to be allocated and provided by a program AIO that requests memory reservation. key 8, program key 9 of program B11 that accesses memory cell 2, program AIO that requests memory reservation, program Bll that accesses memory cell 2, and program key 12 of program AIO that requests memory reservation. It consists of

Note that the length of memory cell 2 is determined by access key table 3.
The ratio does not need to be 1:l as long as the length is a multiple of the length of the access key 4 managed by .

Furthermore, access key 8 and program keys 9 and 12 have the same bit length, and the bit position where the value is "1" in the bit string of access key 8 is the same bit in the bit string of program keys 9 and 12. If the position has the value "1", it is determined that access is possible. Program keys 9 and 12 are stored in a program key register (not shown) when the corresponding program keys I and A10 are running. Note that in the memory cell management mechanism 7, all values in the focus row of its program key (not shown) are "1", and all the memory cells 2 can be accessed.

Furthermore, the access key table 3 is created corresponding to the conversion unit (for example, page) when performing address conversion,
Moreover, it is not necessary to create a conversion unit for a conversion unit that does not require control using the access key 4.

Next, the operation of the memory cell destruction prevention method in the shared memory pool of this embodiment configured as described above will be explained with reference to FIG.

(11) For example, the program AIO requests the memory cell management mechanism 7 to secure memory by specifying the access key 8 "010010". The value "110011" of the program key 12 of the program AIO is arbitrarily selected and used so that the access right is not denied.

That is, the value of the bit string of access key 8 is “1”.
” Program key 12 for the bit position
If the same bit position of the bit string has the value "1", access is possible, so the value of the access key 8 that satisfies this is selected.

(2) The memory cell management mechanism 7 extracts and secures a vacant memory cell 2 from the shared memory pool 1, searches the address translation table 5 from the virtual space address of the secured memory cell 2, and performs a corresponding operation. The specified access key 8 "010010" is stored as the access key 4 in the corresponding position in the access key table 3 indicated by the pointer.

(3) The memory cell management mechanism 7 returns the secured virtual space address of the memory cell 2 to the program AIO.

(4) Next, when the program AIO executes an instruction to update the same memory cell 2, the address translation mechanism 6 converts the virtual space address of the memory cell 2 into a real space address using the address translation table 5, and , program AI in the program key register (not shown)
The access key 4 in the access key table 3 pointed to by the pointer corresponding to the program key 12 "110011" of O and the virtual space address of the address conversion table 5
010010”.

(5) As a result of key comparison, access key 4 “010”
Since all the bit positions of the value "1" in the program key 12 "110011" have the value "1'", the address translation mechanism 6 allows the program AIO to access the memory cell 2 and converts the memory By executing the instruction to update cell 2, memory cell 2 is updated normally.

(6) Next, when another program Bll executes an instruction to update the same memory cell 2, the address translation mechanism 6 converts the virtual space address of the memory cell 2 into a real space address using the address translation table 5. At the same time, the access key 4 "01001" in the access key table 3 pointed to by the pointer corresponding to the program key 9 "011000" of the program Bll in the program key register and the virtual space address of the address conversion table 5
0”.

(7) As a result of key comparison, access key 4 “01001”
All bit positions with value “0” and value “1” are program key 9
Since "011000" does not have the value '1', the address translation mechanism 6 abnormally terminates the instruction to update the memory cell 2 by the program Bll due to an address fault.

Note that the program key 9 of the program Bll is “011”.
Needless to say, if the value is other than 000'', access to the memory cell 2 may be permitted.

Furthermore, in the explanation of the operation of the above embodiment, if there is no access right, the instruction is terminated abnormally due to an address fault, but in the case of a reference instruction, access to memory cell 2 is allowed even if there is no access right. You can also do this.

(Effects of the Invention) As explained above, the present invention divides and manages a shared memory pool into memory cells in a computer system, and extracts and returns the shared memory to a program that uses the shared memory in units of memory cells. In the shared memory management method, access rights can be defined for memory cells, and when accessing a memory cell, an address conversion mechanism compares the access rights of the memory cell and the access rights held by the program, and the access rights are recognized. By generating an address fault so that the memory cell cannot be accessed when the memory cell cannot be accessed, it is possible to effectively prevent the contents of the memory cell from being destroyed by a program that does not have access rights.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a method for preventing memory cell destruction in a shared memory pool according to an embodiment of the present invention, and FIG. 2 shows the operation of the method for preventing memory cell destruction in a shared memory pool of this embodiment. It is a figure for explaining. In the figure, 1... shared memory pool, 2... memory cell, 3... access key table, 4... access key 5... address translation table, 6... address translation mechanism, 7. ...Memory cell management mechanism, 8...Access key 9...Program key 10...Program A. 11...Program B1 12...Program key.

Claims (1)

[Scope of Claims] In a shared memory management method in which a shared memory pool placed in a virtual space is divided into memory cells and managed in a computer system that adopts a virtual memory method, the memory cells of the shared memory pool include: an access key table that stores access keys indicating access rights to memory cells of the shared memory pool; and an access key table that stores address conversion information for converting addresses from virtual space addresses to real space addresses; An address translation table that stores a pointer to an access key of a key table, and manages the shared memory pool in units of memory cells to extract and return memory cells, and searches the address translation table when extracting a memory cell. a memory cell management mechanism that stores an access key of a memory cell at a location in the access key table indicated by a pointer; An address that converts the address into a real space address, traces the pointer, refers to the access key in the access key table, compares it with the program key indicating the access right of the program, and generates an address fault if the access right is not recognized. 1. A method for preventing memory cell destruction in a shared memory pool, characterized by having a response conversion mechanism.