[Bug] A new bug with the option -XX:-UnrollLimitCheck

[feixiangdejiahao]

Description
Run arbitrary program with -XX:-UnrollLimitCheck, Dragonwell8 crashes

Steps to Reproduce

$ java -Xcomp -XX:+UnlockDiagnosticVMOptions -XX:-UnrollLimitCheck -version
#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007faaa4fcd211, pid=755, tid=0x00007faa484d7700
#
# JRE version: OpenJDK Runtime Environment (8.0_322) (build 1.8.0_322-internal-user_2022_03_21_20_47-b00)
# Java VM: OpenJDK 64-Bit Server VM (25.322-b00 compiled mode linux-amd64 compressed oops)
# Problematic frame:
# V  [libjvm.so+0x87b211]  PhaseIdealLoop::build_loop_late_post(Node*)+0x111
#
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#

Expected behavior
openjdk version "1.8.0_322-internal"
OpenJDK Runtime Environment (Alibaba Dragonwell 8.10.11) (build 1.8.0_322-internal-user_2022_03_21_20_47-b00)
OpenJDK 64-Bit Server VM (Alibaba Dragonwell 8.10.11) (build 25.322-b00, mixed mode)

JDK version
openjdk version "1.8.0_322-internal"
OpenJDK Runtime Environment (Alibaba Dragonwell 8.10.11) (build 1.8.0_322-internal-user_2022_03_21_20_47-b00)
OpenJDK 64-Bit Server VM (Alibaba Dragonwell 8.10.11) (build 25.322-b00, mixed mode)

Execution environment

• OS and version: Ubuntu 18.04
• CPU model: Intel(R) Xeon(R) Gold 6240

[y1yang0]

This is possibly a known issue, see JDK-8072422 for more details. You are not supposed to run with this flag switched off. It is more a develop flag then diagnostic used during feature development. We would evaluate if it's reasonable to backport the fix patch to dragonwell 8.

[feixiangdejiahao]

Thanks for your patient help! I thought that since users should not turn the flag off at the run time and the flag is enabled in default, it might be reasonable to remove the option or move it to the debug version rather than simply requiring users not to use it in this way.