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IJ15120: CRASH IN JIT COMPILED CODE DUE TO LACK OF RANGE CHECK

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APAR status

  • Closed as program error.

Error description

  • Error Message: Segmentation Error
.
Stack Trace: The crash location will be in code generated into
memory by the Java JIT compiler - the location will vary but the
faulting instruction will be near a conditional branch.
.

Local fix

  • The problem can be avoided by using -Xjit:disableInlining. Using
this option globally will have a large negative impact on
performance.
To limit the performance impact it is recommended you apply the
disableInlining option to the failing method(s) only by using
the following syntax:
-Xjit:{*class.method*}(disableInlining)
Using disableInlining on a single method is unlikely to result
in a noticeable impact on performance.

Problem summary

  • When a method is inlined by the JIT compiler, the generated code
needs to have a safety check to ensure that the method inlined
at compile-time is the correct method to run when the code is
actually running. This check involves reading an entry at a
fixed offset from the class's virtual function table. The
compiler did not range check the offset against the size of the
lookup table which could lead to a crash reading invalid memory
in certain rare circumstances.

Problem conclusion

  • A range check has been added to the inline method check to
ensure we do not read invalid memory.
.
This APAR will be fixed in the following Java Releases:
   8    SR5 FP31  (8.0.5.31)
.
Contact your IBM Product's Service Team for these Service
Refreshes and Fix Packs.
For those running stand-alone, information about the available
Service Refreshes and Fix Packs can be found at:
           https://www.ibm.com/developerworks/java/jdk/

Temporary fix

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    IJ15120
    • 

  • Reported component name
    JIT
    • 

  • Reported component ID
    620700124
    • 

  • Reported release
    130
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt / Xsystem
    • 

  • Submitted date
    2019-03-29
    • 

  • Closed date
    2019-03-29
    • 

  • Last modified date
    2019-03-29
    • 





    

  • 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


    








      
              
                            

              

              [{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSC9HBA","label":"Just In Time (JIT) Compiler"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"130","Edition":"","Line of Business":{"code":"","label":""}}]
              

                          

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            29 March 2019
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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