IBM Support

PM39036: ABEND 4C5 2A00 IN TMIAP_TERMINATE

A fix is available

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • An abend can occur when a pointer is incorrectly assumed to
    be null following a lock obtain failure.  This can prevent
    a hashtab reference count from being decremented.  When the
    dispatchable unit of work exits the TCP/IP code path the
    DUCB destroy process detects the residual hashtab reference
    and issues the S4C5 abend with reason code xxxx2A00.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All users of the IBM Communications Server   *
    *                 for z/OS Version 1 Release(s) 11, 12, and    *
    *                 13 IP:  NETMONITOR TCPCONNSERVICE Network    *
    *                 Management Interface (NMI)                   *
    ****************************************************************
    * PROBLEM DESCRIPTION: AbendS4C5 rsnxxxx2A00 in the Real-time  *
    *                      TCP/IP Network Monitoring Interface     *
    *                      (NMI) when NETMONITOR ON TCPCONNSERVICE *
    *                      is specified in the profile at TCP/IP   *
    *                      start up or activated via OBEYFILE.     *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    AbendS4C5 rsnxxxx2A00 in the Real-time TCP/IP Network Monitor
    Interface (NMI) when NETMONITOR ON TCPCONNSERVICE is specified
    in the profile at TCP/IP start up or activated via OBEYFILE.
    
    The specification of NETMONITOR ON TCPCONNSERVICE causes the
    Real-time TCP/IP Network Monitoring NMI SYSTCPCN interface
    task to be attached.  The task initialization logic scans the
    TCP connection table and sets an flag in each active TCB to
    indicate a notification should be delivered to the NMI when
    the connection terminates.  A timing window exists where a
    connection is being closed at the same time NMI initialization
    is attempting to obtain the TCB lock to serialize setting the
    flag.  When this occurs the lock obtain fails but the NMI code
    tries to incorrectly release the lock again, resulting in an
    abendS4C5 rsnxxxx2102.  The NMI task recovers from the abend
    and continues to process without performing cleanup on the
    connection table reference.  Later when the NMI task is
    terminated either from a stop of TCP/IP or an OBEYFILE to set
    NETMONITOR OFF the abendS4C5 rsnxxxx2A00 occurs when the
    residual TCP connection table reference is detected.
    +-------------------------------------------------------------+
    + Please check our Communications Server for OS/390 homepages +
    + for common networking tips and fixes.  The URL for these    +
    + homepages can be found in Informational APAR II11334.       +
    +-------------------------------------------------------------+
    

Problem conclusion

  • EZBCTTMI has been amended to process the TCB lock correctly and
    thus avoid the original abends4C5 rsnxxxx2102 that caused the
    residual TCP connection table reference.
    
    * Cross Reference between External and Internal Names
    

Temporary fix

Comments

APAR Information

  • APAR number

    PM39036

  • Reported component name

    TCP/IP V3 MVS

  • Reported component ID

    5655HAL00

  • Reported release

    1B0

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2011-05-12

  • Closed date

    2011-06-13

  • Last modified date

    2011-08-01

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    UK68727 UK68726 UK68728

Modules/Macros

  • EZBCTTMI
    

Fix information

  • Fixed component name

    TCP/IP V3 MVS

  • Fixed component ID

    5655HAL00

Applicable component levels

  • R1B0 PSY UK68726

       UP11/07/12 P F107

  • R1C0 PSY UK68727

       UP11/07/12 P F107

  • R1D0 PSY UK68728

       UP11/07/12 P F107

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.

[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG19M","label":"APARs - z\/OS environment"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"1B0","Edition":"","Line of Business":{"code":"","label":""}},{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSCY4DZ","label":"DO NOT USE"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"1B0","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
01 August 2011