IBM Support

JR37433: TIGHT LOOP DUE TO STACK OVERFLOW CONDITION

A fix is available

Communications Server for Windows, Version 6.4 -- Latest Fixpack

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APAR status

  • Closed as program error.

Error description

  • CS/Linux becomes unavailable.  The system appears to be
in a tight loop, consuming 99% of CPU. Diagnostics show a
stack_overflow_condition that results in a program check.

Local fix

  • 



Problem summary


    

  • USERS AFFECTED:
All users of the TN3270 Server feature.

PROBLEM SUMMARY:
A TN3270E client has issued a large number of SYSREQ keystrokes,
hundreds of them, while in receive state waiting on data from
the host application. When data is received, the TN3270 Server
attempts to process all of those SYSREQs and exceeds the
available stack space.

    



Problem conclusion


    

  • Internal processing has been modified to generate only one
LUSTAT request to the host (which maps to a negative
response to report the loss of the presentation space
integrity) when the SYSREQ key is pressed multiple times on
the tn3270 client.

    



Temporary fix


    

  • efix is now available. Contact Level/2 support for download
instructions.

    



Comments


    

  • 



APAR Information




    

  • APAR number
    JR37433
    • 

  • Reported component name
    COMM SERV NT 6.
    • 

  • Reported component ID
    5639F2503
    • 

  • Reported release
    640
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt
    • 

  • Submitted date
    2010-08-06
    • 

  • Closed date
    2010-08-06
    • 

  • Last modified date
    2010-08-06
    • 





    

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

    
LI75282
    

    • 

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

    • 



Fix information


    

  • Fixed component name
    COMM SERV NT 6.
    • 

  • Fixed component ID
    5639F2503
    • 



Applicable component levels


    

  • R640  PSY  
       
    • 








      
              
                            

              

              [{"Line of Business":{"code":"LOB35","label":"Mainframe SW"},"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSHQNF","label":"Communications Server for Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"640"}]
              

                          

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            07 October 2021
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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