PM17787: CRASH IN JIT_MEM_ALLOC

APAR status

• Closed as program error.

Error description

• Error Message: Crash with SEGFAULT. Customer reports that this
  problem occurs when a particular method gets JIT compiled.
  .
  Stack Trace: 705C8A66  at  jitc.dll  _jit_mem_alloc + 0056
  705C958F  at  jitc.dll  _jit_code_mem_alloc + 001F
  705FA544  at  jitc.dll  _create_sp_offset_info + 00F4
  705CCFC8  at  jitc.dll  _JITGenNativeCode_state + 07C3
  70499A0F  at  jitc.dll  _JITGenNativeCode + 10EF
  704722B1  at  jitc.dll  _jit_compiler_entry + 0C51
  704735EC  at  jitc.dll  __jit_fast_compile + 026C
  706400EB  at  jitc.dll  __gate_code + 004B
  .
  NA
  

Local fix

• NA
  

Problem summary

• Crash with SEGFAULT. Customer reports that this problem occurs
  when a particular method gets JIT compiled.
  

Problem conclusion

• This defect will be fixed in:
  1.4.2 SR13 FP6
  .
  The crash occured in the code generation phase of the JIT
  compilation of the customer's method, which has quite many
  number of StringBuffer's constructor and append methods inlined
  into it. The codegen is a dual pass routine, in the first pass,
  compiler runs through the optimized bytecode and estimates the
  size of the native code buffer to be allocated, and in the
  second pass, actual code is generated into the code buffer which
  is allocated based on the size information obtained from pass 1.
  Due to an error in the size computation logic, the generated
  code size becomes more than the estimated size, and overflows
  into the memory allocation structures. Next time when an
  allocation request was issued, the corrupted data structures
  caused the crash. The issue is fixed in latest SDK.(SR13 FP6)
  .
  To obtain the fix:
  Install build 20100909 or later
  

Temporary fix

Comments

APAR Information

• 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

  JAVA(1.3/1.4 CO

• Fixed component ID

  5648C9800

Applicable component levels

• R42A PSN

     UP

• R42L PSN

     UP

• R42W PSN

     UP

• R420 PSN

     UP