Software-Initiated Dumps
Generally, a software error occurs when a sequence of instructions
executed by a processor results in a condition that is incompatible
with the design of the software system. Software errors have a variety
of symptoms. Some typical symptoms are
- Symptom
- Software Error
- Loop
- A sequence of instructions is executed over and over again, infinitely.
- Wait
- The software system cannot find work to do, or it encounters a condition that cannot be resolved.
- Lockout
- A user ID has become disabled, nondispatchable, or has no work-tasks to be run.
- Storage overlay
- A program has stored data in the wrong location in real storage.
- Invalid data
- A system control block or data area contains data that is inconsistent or erroneous.
- Invalid address
- A control block or data area contains an address that is outside the storage areas to which the program has access; or, a control block or data area points to a nonexistent control block. Because some addresses are generated by programs from data in control blocks, an invalid address can be generated if the data is in error.
- Invalid instructions
- An instruction is found that does not conform to the system architecture, possibly because it has been modified in main storage.
Invalid addresses and instructions result in program checks. The other kinds of software errors are usually detected by CP as abnormal conditions. Both result in abnormal termination of CP and a dump being taken.