APAR status
Closed as program error.
Error description
Error Message: A SIGSEGV is received, but other symptoms are possible depending on how the corrupted memory is used. . Stack Trace: N/A . The problem can only occur when using java bytecodes that are generated by something other then javac. The case that was reported was using bytecodes generated by Groovy. The problem occurs when the java bytecode "multianewarray" is used with the number of dimensions set to 1. This is not something that javac would ever generate since the same thing can be accomplished using "anewarray" in a more compact fashion.
Local fix
The problem can be avoided by using the following java command line option: -Xjit:disableArrayCopyOpts Use of this option will have an effect on performance but in most cases it will be very minor.
Problem summary
The JIT was assuming that the use of "multianewarray" would always result in a 2 or more dimensional array with a reference array that links all the dimension arrays together. When "mulianewarray" is used to create a one dimensional array there is no reference array but the JIT would mark it as being a reference array. If an arraycopy was executed against this array it would multiply the offsets and length by the size of a reference potentially resulting memory corruption.
Problem conclusion
The JIT was modified so that uses of "multianewarray" for one dimensional arrays does not mark the resulting array as a reference array. . This APAR will be fixed in the following Java Releases: 7 SR9 FP50 (7.0.9.50) 6 SR16 FP30 (6.0.16.30) 7 R1 SR3 FP50 (7.1.3.50) 6 R1 SR8 FP30 (6.1.8.30) 8 SR3 FP10 (8.0.3.10) . 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
IV85454
Reported component name
JIT
Reported component ID
620700124
Reported release
260
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2016-06-03
Closed date
2016-06-09
Last modified date
2016-06-27
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
R260 PSY
UP
R600 PSY
UP
R130 PSY
UP
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Document Information
Modified date:
27 June 2016