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IV58136: INACCESSABLE ADDRESS WHEN RUNNING UNDER HCR MODE ON X86 PLATFORM S

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • Error Message: Segmentation fault where inaccessible address is
the same value as the instruction pointer.
.
Stack Trace: N/A
.

Local fix

  • This issue can be worked around by using the
-Xjit:disableVirtualGuardNOPing.  This avoids the particular
code patching that causes the bad branch to be inserted into the
compiled method.

Problem summary

  • The problem is caused when two or more HCR guards are placed on
the same instruction, and that instruction has an assumption
registered to it.

Problem conclusion

  • This APAR will be fixed in the following Java Releases:
   6 R1 SR8 FP20  (6.1.8.20)
   7 SR9 FP30   (7.0.9.30)
   7 R1 SR1       (7.1.1.0)
.
The HCR guards will properly insert padding to avoid writing
over the instruction with the assumption registered to it.  This
prevents the bad branch from ever materializing.

Update: Fix has been added to Java 7.0 for the Q1 2016 release.

Temporary fix

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    IV58136
    • 

  • Reported component name
    JIT
    • 

  • Reported component ID
    620700124
    • 

  • Reported release
    130
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt / Xsystem
    • 

  • Submitted date
    2014-03-28
    • 

  • Closed date
    2014-04-08
    • 

  • Last modified date
    2016-01-13
    • 





    

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

    • 

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

    • 



Fix information


    

  • Fixed component name
    JIT
    • 

  • Fixed component ID
    620700124
    • 



Applicable component levels


    

  • R130  PSY
       UP
    • 








      
              
                            

              

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Document Information


            

            


                        

            Modified date:
            

            13 January 2016
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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