Re: Calling export procedure using QZRUCLSP - Problem with parmpass byValue

Lim Hock-Chai wrote:
>              CALL       PGM(QZRUCLSP) PARM( +
>                         'SPPGTR    *LIBL     ' +
>                         &PROC              +
>                         x'00000001'        +
>                         x'00000002'        +
>                         x'00000001'        +
>                         x'00'              +
>                         &SCANJOBCNT        +
>                         &BBCD)

The x'00' is the error-code parameter.  It's only one byte long, but it
should be at least 4 bytes long (technically it should be at least 8
bytes long, but I think that if the first 4 bytes are x'00000000' that
the APIs don't use anything further).

If you pass x'00' as a parameter, the API will see the value x'00404040'
(4210752) as the bytes-provided field of the error-code parameter
(because CL will pad the value with blanks to make a 32-byte value). 
The API will feel free to modify up to 4210752 bytes of the error code
parameter.  The first 32 bytes will be ok, since CL would have allocated
that much for your parameter, but if it modifies anything beyond 32
bytes, you could get unpredictable results due to storage corruption.