PURPOSE: To reduce the overhead of restoration processing and suppress the infinite loop operation of the system in the patched state of a load module by restoring the system to a state before the patching by utilizing patch data such as address information of the load module.
CONSTITUTION: When various data need to be gathered by patching owing to the occurrence of a fault, etc., an operator sets the necessary patch data 3a on a disk device 1a and indicates the number of the patch data to place a patch program 2b in operation. Consequently, the load module 2a on the disk device 1a is rewritten for the patching. Then the patch program 2b moves the load module 2a to a main storage device 2a for the system and executes it, and gathers the patching position and various data, and a patch removing program 3b restores the patched part of the load module 2a to its original state to put the system back to the state before the patching.
BOKU SHIYOUSEKI
NISHIKAWA SHIGEMI
