JP2000099372A - Computer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtains a computer system which surely performs core dump even if such a situation where even an OS performs runaway occurs. SOLUTION: When an application program 22 detects abnormality and accesses a system-down function, a system program 21 sets a flag 41 and activates a boot program 31. When a user recognizes the abnormality and instructs reset from a front panel 51, a PUI 50 issues an interrupt signal, a system program 21 sets value to a general purpose register 61, and the boot program 31 is activated by subsequent reset by the PUI 50. The boot program 31 detects jump to a zero address from a stack 11, also detects continuous reset from a debug board 70 to set the flag 41, also examines the flag 41 and the register 61, activates a core dump program 32 if a core dump request exists to write contents of a RAM 40 in an HDD 20 and also compresses them to store them in the HDD 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer system and, more particularly, to write the contents of a main storage device to a large-capacity storage device such as a hard disk (hereinafter referred to as HDD) when a hang-up or abnormality occurs in the system. It relates to core dump processing.

[0002]

2. Description of the Related Art In a computer system such as a workstation, when a system hang-up is detected or an application terminates abnormally for some reason, data stored in a main storage device at the time of occurrence of the abnormality is detected. Is transferred to a larger capacity external storage device such as an HDD. Such processing is generally called core dump processing. These core dumps are used to rescue the system from an unusual condition, and if the remedies fail,
The core dumped data will be used in the subsequent analysis performed to determine the cause.

[0003]

By the way, in a conventional computer system, a core dump process is performed immediately when an abnormality occurs. That is, when the OS (operating system) detects an abnormality by itself, such as detecting a hang-up with a monitoring timer, or receives a report of an abnormality from an application or hardware, the OS
Performs core dump processing as part of the abnormal processing. After that, the OS reboots (restarts) the system when all the abnormal processes including the core dump process are completed.

As described above, in the conventional computer system, the core dump process is performed on the assumption that the OS is operating normally. However, in a situation where an abnormality occurs, it is sometimes impossible to predict what is happening in the system, and in some cases, even the OS may run out of control. In particular,
When a computer system is used for an embedded device or the like, it is often necessary to operate the system under a severe environment, and there is a high possibility that the OS may not operate normally.

As described above, if the conventional method is employed, it cannot be guaranteed that the core dump processing can always be performed reliably, and the remedy performed based on the result of the core dump processing and investigation of the cause are effective. There is a problem that can not be performed. The present invention has been made in view of the above points, and an object of the present invention is to ensure that core dump processing is performed and contents of core dumped contents are reliably performed even in a critical situation where even the OS runs out of control. An object of the present invention is to provide a computer system capable of improving reliability.

[0006]

In order to solve the above-mentioned problems, according to the present invention, a core dump for writing the contents of a main memory of a system to an external storage device when an abnormality occurs in the system is provided. In the computer system to be performed, holding means for holding request data indicating presence / absence of the request for core dump, and request data indicating the request for core dump are set in the holding means when an event indicating occurrence of the abnormality is detected. Setting means, and a core dump for performing the core dump on condition that the request data indicates the core dump request after the reboot process of the system started in response to the occurrence of the abnormality is completed. Means. According to a second aspect of the present invention, in the first aspect of the present invention, the holding means includes a flag provided at a predetermined position on the main memory.
According to a third aspect of the present invention, in the first or second aspect, the holding means includes a non-volatile medium whose contents are not affected by hardware reset of the system.

[0007] The invention according to claim 4 is based on claims 1 to
3. The invention according to claim 3, further comprising storage means for storing a jump destination address when a jump occurs in a program running on the system, wherein the setting means comprises:
The present invention is characterized in that it detects that the jump destination address is an address where the program should not run, and sets the request data in the holding means. According to a fifth aspect of the present invention, in the first aspect of the present invention, the core dump unit writes the contents of the main storage to a fixed area on the external storage device. And a storage unit for storing the contents of the main memory written in the fixed area in a storage area on the external storage device. According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the storage means is incorporated in an application program running on the system, and compresses the contents of the main memory before the external storage. It is characterized in that it is stored in the device.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, the outline of the present invention will be described. Considering the problems in the conventional technology, it can be understood that the program for realizing the core dump function needs to operate normally regardless of the previous system state, and can operate without the intervention of the OS. There must be. For that purpose, it is necessary to perform the core dump process in a state where the OS has not yet started up, for example, immediately after the power is turned on, that is, in the initialization phase at the time of booting the system.

In view of the above, according to the present invention, a core dump process is performed at the time of rebooting, instead of performing a core dump immediately upon occurrence of an abnormality as in the related art. here,
Requests for core dumps can occur in various states of the system. Therefore, in the present invention, the information for the core dump request is left on the system using various methods, the boot program is started, and the core dump program is started after the system is normally started by the reboot operation by the program. And doing a core dump.

[0010] By the way, instead of having the core dump function on the boot program side, O which runs on the system
It is conceivable that all programs including S have a core dump function. However, various application programs run on the system, such as a general application program that the user normally runs, a service program for performing initial settings and status confirmation of the system, and an inspection program used for inspecting the system during production. I do. Incorporating the core dump function in all of these programs in a redundant manner not only wastes the main storage area but also increases the burden on developing the application. In this regard, if the core dump function is integrated as a single core dump program, the main memory will not be wasted, but it is necessary to link the core dump program to all the applications, which again imposes a burden on application development. Therefore, it is best to incorporate the core dump function into the boot program.

FIG. 1 is a block diagram showing the configuration of the computer system according to the present embodiment. In FIG. 1, a CPU (Central Processing Unit) 10 includes a ROM 3
By executing various programs stored in the RAM 40 and the RAM 40, the operation of each unit in the system is generally controlled. This C
The PU 10 includes a program counter and registers as well as a general microprocessor and the like, and also includes a stack 11. The CPU 10 is configured to set a jump destination address in the stack 11 every time a jump instruction is executed.

The HDD 20 stores a system program 21 and an application program 22 loaded on a RAM 40 (described later) in advance. Among these, the system program 21 corresponds to the OS. The application program 22 performs a normal operation as an application, and has a function of performing compression processing on collected core dump data and storing the data on the HDD 20 after the core dump processing is completed.
At that time, when the boot program 31 starts the core dump program 32 and performs the core dump process, the system program 21 is notified of the fact,
The system program 21 records in the RAM 40 whether or not a core dump has been performed based on the notification as a record. The application program 22 can know whether or not a core dump has been performed by referring to the contents of this record. The reason why such a storage function is incorporated into the application program 22 instead of the boot program 31 is that a large-size process called a compression process is included. Due to the difficulty in resident in the city. Therefore, if the program size is reduced by omitting the compression process,
It is also possible to provide the boot program with a storage function.

In addition, the HDD 20 is provided with a fixed area 23 and a storage area 24 as shown in FIG. The fixed area 23 is an area to which part or all of the contents of the RAM 40 is transferred by the core dump process, and the storage location of the fixed area 23 on the HDD is predetermined. Therefore, when the core dump process is performed, the fixed area 2
3 will be rewritten each time. on the other hand,
The storage area 24 is a fixed area 2 updated every time a core dump is performed.
3 is an area for sequentially accumulating the contents of 3 and is constituted by a file system under the control of the application program 22. The main reason for providing the storage area 24 is to store all the core dumps collected when an abnormal state occurs many times, and perform a cause analysis by integrating them.

Next, a ROM (read only memory) 3
0 is a boot program 31 for booting the system and a core dump program 32 for performing core dump processing.
I remember. In the present embodiment, it is assumed that the start address of the boot program 31 is 0x “a00000000” (0x is a notation indicating a hexadecimal number). Here, in the computer system according to the present embodiment, the address 0x “a00000000” and the address “0” are equivalent. That is, logically, a 32-bit value can be specified as an instruction address.
Is such that the upper 4 bits of the instruction address are always regarded as "0", and the address x "a00000000" is "0".
Address is treated as equal. However, if the address "0" is specified as the jump destination when jumping to the boot program 31, it is impossible to distinguish the case where the program jumps to the address "0" due to a bug in the program. Therefore, in the present embodiment, when the system program 21 or the like intentionally jumps to the boot program 31, 0x “a00
The program is created to jump to the address "00000".

Next, a RAM (random access memory)
Reference numeral 40 stores the system program 21 and the application program 22 that the boot program 31 loads from the HDD 20, and also stores variables used by these programs. In addition, the RAM 40 stores a 1-byte flag 41 (details will be described later) at a predetermined position. Next, a PUI (panel user interface) 50 is an interface circuit that receives operation contents when the user operates the front panel 51 from the front panel 51 and transmits the operation contents to the CPU 10. For example, the PUI 50 knows that a reset button (not shown) on the front panel 51 has been pressed, and sends an NMI signal (Non-Maskable-I
nterrupt; non-maskable interrupt request).
Similar to a general microprocessor, in the present embodiment, there are a maskable interrupt (so-called IRQ) and a non-maskable interrupt as an interrupt to the CPU. The NMI signal is the interrupt request with the highest priority. The PUI 50 also has a function of sending a reset signal to each part of the system after a certain period of time has passed since sending the NMI signal to the CPU 10.

Next, an RTC (real-time clock) 6
Reference numeral 0 denotes a calendar integrated circuit that operates under the control of the CPU 10 and has a general calendar function and a general-purpose register 61 that can be used for general purposes. The contents of the general-purpose register 61 are readable and writable by the CPU 10, and the general-purpose register 61 is backed up by a battery so that the content is retained even after a hardware reset. In the present embodiment, it is assumed that the general-purpose register 61 is composed of 4 bits. Next, the debug board 70 is a circuit dedicated to debugging that is connected only at the development stage of the system.

Although a core dump request can occur in various system states as described above, in the present embodiment, a core dump request is made in response to an event described below. [Opportunity] Reboot request with core dump by program When the system program 21 or the application program 22 detects a software abnormality while the program is running, a function prepared in advance in the system program 21 (hereinafter referred to as a SystemDown function) Call. This SystemDown function writes a predetermined value to the flag 41 on the RAM 40, thereby setting a core dump request. This predetermined value may be any value, but in the present embodiment, it is assumed that “0” is set when there is no core dump request, and when the core dump request is set, any fixed value other than “0” is set. Is written as 0x “AA”. Also, Syste
After the mDown function stores a predetermined value in the flag 41, the start address of the boot program 31 (that is, 0x “a00
00000 ") to start the reboot process.

When the user recognizes that the operation of the system is abnormal, the user presses a reset button provided on the front panel 51 and issues a hardware reset to the system. Perform a wear reset instruction. As described above, when the reset button is pressed, the PUI 50 generates an NMI signal, and this NMI signal triggers a core dump request to the system program 21 which is responsible for interrupt processing.

[Trigger] Consecutive 2 from debug board
Reset Instructions As described above, at the development stage of the system, the debug board 70 is connected for operation confirmation. Therefore, in order to intentionally reproduce a situation in which a core dump is to be performed from the debug board 70 (that is, a situation corresponding to the occurrence of an abnormality), a case in which a hardware reset instruction is issued twice consecutively from the debug boat 70 This is considered a core dump request. It should be noted that whether the reset instruction is given twice consecutively from the debug board 70 is determined by the boot program 31.
Judge. That is, the boot program 31
A counter is provided on the counter 40. The counter value is incremented by "1" every time it is started, and the counter value is set to "2" immediately before the core dump processing performed thereafter.
, And a process of generating a core dump request and a process of initializing a counter value to “0” are sequentially performed. The reason that the condition of two consecutive executions is given is that the debug board 70 may issue a hardware reset even when the core dump is not performed.

[Opportunity] Jump to address "0" As long as the application or the OS is correctly programmed, it is not usually considered that the program jumps to the address "0". However, if a bug exists in the application or the like, a situation may occur in which the program jumps to the address “0”. For example, when performing a function call, the start address of the function to be called is specified as a pointer. In this case, if a correct value is not set in the pointer due to a bug in the program, "0" set by default is set in the pointer, and as a result, "0" is set.
The address jumps (that is, the start address of the boot program 31). For this reason, if the boot program 31 detects that it has been started by jumping from the address "0", it determines that this is a core dump request.

Next, means for realizing a core dump after a reboot will be described. [Implementation Means] This implementation means is based on the assumption that at least the OS is operating normally, and corresponds to the above-mentioned opportunity. In the realization means, SystemDown
Referring to the flag 41 set by the function, the content is x "A
If A ", it is determined that a core dump request exists. As described above, the SystemDown function finally returns 0.
x The program branches to address "a00000000" to activate the reboot process by software. In other words, since the above-mentioned trigger does not involve a hardware reset, the contents stored in the RAM 40 can be trusted. Therefore, there is no problem even if the flag 41 is provided on the RAM 40, the value is set in the flag 41 when an abnormality occurs, and it is determined whether the core dump process is necessary or not according to the contents of the area after the reboot. Further, this realizing means has an advantage that various data at the time of an error other than the flag 41 can be left in the RAM 40 together.

[Implementation means] This implementation means is used when it is necessary to perform a hardware reset and then reboot, such as when the system is hung up or when the OS is running out of control. It is. In other words, this realization means is for the above-mentioned opportunity or opportunity (although it can also be used in the case of an opportunity, etc.). As described above, when the hardware reset is performed, the reset operation and the instruction execution operation may overlap with each other and the RAM 40 may be unexpectedly rewritten, and the contents thereof are unreliable. Therefore,
In such a case, the realizing means using the flag 41 on the RAM 40 cannot be used.

From the above, according to the present realization means, RT
The general-purpose register 61 provided in the C60 is used. For example, when the user presses the reset button on the front panel 51, the system program 21
In the process of interrupt processing by the I signal, the general-purpose register 61
For example, x “a” is written as a fixed value. Thereafter, the PUI 50 performs a hardware reset on each part of the system after a certain time from the NMI signal. In this case as well, the contents of the general-purpose register 61 remain unchanged. Therefore, the boot program 3 started after the hardware reset
If the content of the general-purpose register 61 is 0x “a”, it is considered that a core dump request exists. In addition, after performing the core dump process, the boot program 31 initializes the content of the general-purpose register 61 to “0”, in preparation for a case where the next core dump request is set.

In the actual operation process, the boot program 31 always checks both the flag 41 and the general-purpose register 61 irrespective of whether the boot program 31 is started by software or by hardware. That is,
General-purpose register 6 if activated by hardware
1 indicates that a core dump request has been set, and if activated by software, there is no core dump request in the general-purpose register 61 and a core dump request is set only in the flag 41. In addition, by adopting a configuration having storage means backed up by a battery such as a nonvolatile memory,
Such storage means can be used in place of the general-purpose register 61.

[Implementation Means] This implementation means is used when the boot program 31 is started as a result of jumping to the address "0", and is an implementation means corresponding to the above-mentioned trigger. In this realizing means, the boot program 31 refers to the jump destination address held in the stack 11, and if the content is “0”, the boot program 31 reads “0”.
The jump from the address is considered, and the core dump program 32 is activated to perform the core dump processing.

Next, a core dump process performed in the computer system having the above configuration will be described. In addition,
In the following, it is assumed that the system program 21 and the application program 22 have already been read into the RAM 40, and the OS and the application are running and in a situation.

First, the case where the above-mentioned trigger occurs will be described. If any abnormality is detected during execution of the application program 22, the application program 22 executes SystemDow in the system program 21.
Call the n function. As a result, the system program 21 writes 0x “AA” in the flag 41 to set a core dump request, and then jumps to the start address of the boot program 31. The boot program 31 performs an initialization process and the like which are required at least to normally start up the system by executing an existing boot process. next,
The boot program 31 checks the contents of the flag 41 and the general-purpose register 61, and sets the flag 41 to 0x “A
A "is set, the core dump request is recognized, the core dump program 32 is activated, and the contents of the RAM 40 are sequentially written to the fixed area 23 on the HDD 20.

After the core dump processing, the boot program 31 clears the flag 41 and the general-purpose register 61 and sets data in the RAM 40 for notifying the system program 21 that the core dump has been performed. Next, the boot program 31 loads the system program 21 from the HDD 20 onto the RAM 40, delegates processing to the system program 21, and starts up the OS. Thereafter, the system program 21 sets a record indicating that a core dump has been performed, reads the application program 22 from the HDD 20, and activates it. The application program 22 knows that a core dump has been performed from the above record before performing the original processing of the application, reads out the core dump data collected on the fixed area 23, performs compression processing on the core dump data, and then stores the data in the storage area 24. A new file is created above, and the compressed core dump data is written to the file. For example, first, the core dump data is stored in the file F1 as shown in FIG. 2, and thereafter, each time the core dump processing is performed, the files are sequentially created as a file F2, a file F3,. It accumulates.

Next, a case where the above-described trigger occurs will be described. The system hangs,
When the user notices that there is no response even if the user gives an instruction to the system from the front panel 51, the user presses a reset button on the front panel 51. As a result, the PUI 50 sends an NMI signal to the CPU 10. The CPU 10 activates an interrupt process on the system program 21 in response to the NMI signal, and in the interrupt process, stores the fixed value 0x “a” in the general-purpose register 61.
To set a core dump request. After this, PU
The I50 sends a reset signal to each part in the system after a fixed time from sending the NMI request to perform a hardware reset. By this hardware reset, each unit in the system returns to a normal state, and the boot program 31 runs from the head address of the ROM 30. The boot program 31 checks the contents of the flag 41 and the general-purpose register 61 after performing the existing boot processing in the same manner as in the case of the trigger.
Therefore, the core dump program 32 is caused to perform a core dump process. Thereafter, the OS and the application start up sequentially, and the application program 22 performs a core dump data accumulation process.

Next, the case where the above-mentioned trigger occurs will be described. When the boot program 31 is activated by the debug boat 70 giving the first hardware reset instruction, the boot program 31 increases the value of the counter on the RAM 40 by "1" and checks whether the value is "2". . In this case, since the value of the counter is “1”, the boot program 31 subsequently executes the existing boot processing. If there is a second hardware reset instruction from the debug board 70 during this boot processing, the boot program 31 is started again after the reset operation corresponding to the instruction. As a result, the boot program 31 adds “1” to the value of the counter on the RAM 40, and detects that the reset value is “2”, which indicates that it is a continuous reset instruction from the debug board 70, After writing 0x “AA” to the flag 41 to set a core dump request, the counter value is initialized to “0”. Next, the boot program 31 performs an existing boot process as in the case of the first hardware reset. When this boot processing is completed, the boot program 3
1 is an opportunity or a flag 41 as in the case of the opportunity.
Then, the general-purpose register 61 is checked, a core dump request is detected from the contents of the flag 41, and the core dump program 32 performs a core dump. Thereafter, the OS and the application start up sequentially, and the application program 2
2 performs core dump data accumulation processing.

Next, a case where the above-described trigger occurs will be described. It is assumed that a bug exists in the application program 22 and the program jumps to the address “0” during the processing. Upon execution of this jump instruction, “0” is set in the stack 11. Since the address “0” is also the head address of the boot program 31 as described above, the processing of the CPU 10 shifts to the boot program 31. The boot program 31 refers to the contents of the stack 11 and detects that the contents are “0”, and knows that the boot program 31 itself has been started in a normally impossible sequence of jumping to the address “0”. So, boot program 3
1 writes 0x “AA” in the flag 41 to set a core dump request. Thereafter, the boot program 31 performs the existing boot processing, and then sets the core dump request in the flag 41.
2 is started and core dump processing is performed. Thereafter, the OS and the application sequentially start up, and the application program 22 performs a core dump data accumulation process.

As described above, the core dump function is activated by the boot program 31.
In this way, the area on the RAM 40 is not wasted and the boot program 31 is basically used.
Since it is only necessary to develop a program relating to the core dump function for only, the burden on program development can be reduced.

Further, as described above, the trigger of the core dump is not always found when the application program is executed. In other words, since the trigger occurs asynchronously with the running of the application program, the application cannot recognize the trigger and can detect the trigger only when the boot program 31 is executed. Further, the trigger is known only when the boot program 31 is started by jumping to the address “0”.
Therefore, in the present embodiment, the presence of a core dump request is left in the flag 41 or the general-purpose register 61, and
When the boot program 31 is started, a core dump request is detected from these pieces of information and core dump processing is performed. Therefore, the core dump function can be centrally managed on the boot program 31 side.

[0034]

As described above, according to the present invention, when an event indicating the occurrence of an abnormality is detected, request data indicating a request for a core dump is set, and the reboot process started upon occurrence of the abnormality is performed. After the completion, the request data is checked, and if a core dump is requested, the core dump is performed. As a result, the core dump is performed in a state where the system has started up normally in the reboot process, so that even in a critical situation where even the OS runs out of control, the core dump process can be reliably performed. Further, since core dump requests generated in various states of the system are once set as request data and the core dump request is determined at the time of reboot, the core dump function can be centrally managed by a boot program or the like.

According to the second aspect of the present invention, the core dump request is set by a flag provided at a predetermined position in the main memory, so that an abnormality that does not require the intervention of a hardware reset occurs. In the above, the core dump after the reboot can be realized without providing special hardware. According to the third aspect of the present invention, since a core dump request is set using a non-volatile medium whose contents are not affected by a hardware reset, a situation in which a hardware reset is required due to a hang-up or the like is caused. Even in such a case, a core dump can be reliably performed at the time of a subsequent reboot.

According to the fourth aspect of the present invention, a jump destination address when a jump occurs in the program is stored, and when the jump destination address is an address where the program cannot run, a core dump request is issued. Is set. As a result, a core dump can be performed by catching an event such as a jump to the address “0” that often occurs due to a bug in the program. According to the fifth aspect of the invention, a core dump is performed in a fixed area on the external storage device, and the contents of the main memory written to the fixed area are stored in the storage area on the external storage device. As a result, when an abnormal state occurs many times, the collected core dump can be comprehensively applied to the cause investigation. In the invention according to claim 6, the function of the storage means is incorporated in the application program, and the collected core dump is subjected to compression processing before being stored. As a result, it is possible to reduce the storage area required for accumulating the core dump while addressing the problem that it is difficult to incorporate the compression processing into the boot program.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a computer system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an area allocation on an HDD 20 in the embodiment.

[Explanation of symbols]

10 CPU, 11 Stack, 20 HDD
21 ... system program, 22 ... application program, 23 ... fixed area, 24 ... storage area,
30 ROM, 31 Boot program, 32
Core dump program, 40 RAM, 41 Flag, 50 PUI, 51 Front panel, 60
... RTC, 61 ... General purpose register, 70 ... Debug board.

Claims (6)

[Claims] 1. A computer system for performing a core dump for writing the contents of a main memory of the system to an external storage device when an abnormality occurs in the system, comprising: holding means for holding request data indicating whether or not there is a request for the core dump; Setting means for setting request data indicating a request for the core dump in the holding means at a point in time when an event indicating the occurrence of the abnormality is detected; and rebooting of a system started in response to the occurrence of the abnormality is completed. And a core dump unit for performing the core dump on condition that the request data indicates the core dump request. 2. The computer system according to claim 1, wherein said holding means includes a flag provided at a predetermined position on said main memory. 3. The computer system according to claim 1, wherein the holding unit includes a nonvolatile medium whose contents are not affected by a hardware reset of the system. 4. A storage means for storing a jump destination address when a jump occurs in a program running on the system, wherein the setting means is such that the jump destination address is an address at which the program should not run. 4. The computer system according to claim 1, wherein said request data is detected and said request data is set in said holding means. 5. The core dump unit writes contents of the main storage to a fixed area on the external storage device, and writes contents of the main storage written to the fixed area on the external storage device. The computer system according to claim 1, further comprising a storage unit that stores the data in the storage area. 6. The storage unit according to claim 1, wherein the storage unit is incorporated in an application program running on the system, compresses the contents of the main storage, and stores the compressed content in the external storage device. 6. The computer system according to claim 5.