A fix is available
APAR status
Closed as program error.
Error description
V11 PTF UI18946 PTF has made the size of the DSN3EPX load module grow to x'AF18' bytes which exposed a problem with the page protection code for protecting the early code modules. Small key 7 E/CSA storage requests can be allocated in the residual 232 bytes of the page that was protected, resulting in S0C4-04 abends attempting to update the storage. Additional symptoms: ABEND0C4-04 in DSN3AMI2 ABEND0C4-04 in DSN3CL0X ABEND0C4-04 in DSN3AMI2 ABEND0C4-04 in DSN3AC0X ABEND0C4-04 in DSN9SCNE ABEND0C4-04 in DSN3RS0X ABEND0C4-04 in DSN9SCNM ABEND0C4-04 in DSN3UR00 ABEND0C4-04 in DXRRL050
Local fix
Set DSN6SPRM PROTOFF=YES in all DB2 ZPARMs that run with V11 early code.
Problem summary
**************************************************************** * USERS AFFECTED: All users of DB2 for zOS. * **************************************************************** * PROBLEM DESCRIPTION: ABEND0C4-04 attempting to store into * * storage allocated from a key 7 SP241 * * page that has been invalidly page * * protected. Most likely the abends * * will occur in DB2 or IRLM modules. * **************************************************************** * RECOMMENDATION: * **************************************************************** If the DSN6SPRM PROTOFF=NO DSNZPARM option is set (or is set to NO by default), DB2 will page protect the complete 4K pages of the DB2 Early code to prevent code overlays. The end of the DSN3EPX load module was not being calculated correctly by DSN3UR00. This did not cause a problem until all the DB2 Version 11 Early Code PTFs up to and including UI18946 were applied. This caused the size of the DSN3EPX load module to become x'AF18' bytes in length. Since the module is loaded into storage allocated on a page boundary, the module then extended into the last x'100' bytes of the last 4K page. This exposed a base code problem calculating the ending address of the load module. DB2 then incorrectly page protected the last page which contained 232 bytes of available space in the key 7, SP241 page. If another storage request allocated storage in this page, any update to the storage would abend with S0C4-04 as the page is page protected. There is no problem with the code change in PTF UI18946, but it was decided to flag the PTF as PE so users would not be exposed to this base code problem.
Problem conclusion
The incorrect ending address of the DSN3EPX load module stored in the EEPL control block has been corrected in DSN3UR00.
Temporary fix
********* * HIPER * *********
Comments
APAR Information
APAR number
PI21701
Reported component name
DB2 ZOS SUBSYS
Reported component ID
5740XYR01
Reported release
B10
Status
CLOSED PER
PE
YesPE
HIPER
YesHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2014-07-09
Closed date
2014-07-23
Last modified date
2014-09-03
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI19902 UI19903
Modules/Macros
DSNAPRHX DSN3UR00
Fix information
Fixed component name
DB2 ZOS SUBSYS
Fixed component ID
5740XYR01
Applicable component levels
Fix is available
Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.
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Document Information
Modified date:
04 March 2021