IJ57689: JVM CRASHES ON WINDOWS WITH INTEL AMX ENABLED

APAR status

• Closed as program error.

Error description

• Error Message: Intermittent and unpredictable crashes. Multiple
  symptoms are possible including but not limited to asserts, GPFs
  and out of memory errors. Perhaps the most common group of
  outcomes relate to failures during stack walking, since the
  stack header is vulnerable to being overwritten.
  .
  Stack Trace: N/A
  .
  The problem only occurs when running on newer generation
  processors that support Intel AMX using a version of Windows
  that enables AMX by default. At time of writing this has been
  reported on Windows Server 2022 and 2025.
  

Local fix

• The problem can be avoided by setting the Java command line
  option
  -Xjit:disableTraps
  If there is already a -Xjit option being used, combine
  disableTraps with existing sub-options using a comma separator
  (e.g., -Xjit:existingOption,disableTraps).
  

Problem summary

• On Windows versions that enable AMX support, the AMX registers
  are written to the stack during signal handling. This increases
  the required space by slightly more than 8k which can overflow
  the available storage and corrupt the contents of adjacent
  memory. The variability in what was stored in the corrupted
  memory leads to a large number of possible outcomes and
  symptoms.
  

Problem conclusion

• The amount of space allocated to allow for register storage
  during signal handling has been increased.
  .
  This APAR will be fixed in the following Releases:
  .
  IBM Semeru Runtimes
  25              25.0.3.0
  21              21.0.11.0
  17              17.0.19.0
  11              11.0.31.0
  IBM SDK, Java Technology Edition
  8    SR8 FP65  (8.0.8.65)
  .
  Downloads and supplementary documentation can be found at the
  following locations:
  - For non z/OS operating systems:
  - IBM Semeru Runtimes, Version 11 and later
   https://www.ibm.com/semeru-runtimes/downloads/
  - IBM SDK, Java Technology Edition, Version 8
   https://www.ibm.com/support/pages/java-sdk-downloads/
  - For the z/OS operating system:
  - Java SDK Products on z/OS
   https://www.ibm.com/support/pages/java-sdk-products-zos
  

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

  JIT

• Fixed component ID

  620700124

Applicable component levels