Corrupted object in OpenJDK #1378
Description
First seen in https://github.com/mmtk/mmtk-core/actions/runs/17287383210/job/49067075231?pr=1372. It should be unrelated with the PR. It is likely a regression from #1364 or related with reference processing in enabled in the tests in #1360.
/home/runner/work/mmtk-core/mmtk-core/mmtk-openjdk/.github/scripts/../../repos/openjdk/build/linux-x86_64-normal-server-fastdebug/jdk/bin/java -XX:+UseThirdPartyHeap -server -XX:MetaspaceSize=100M -Xms32M -Xmx32M -jar /home/runner/work/mmtk-core/mmtk-core/mmtk-openjdk/.github/scripts/../../dacapo/dacapo-2006-10-MR2.jar lusearch
[2025-08-28T06:35:47Z INFO mmtk::memory_manager] Initialized MMTk with GenCopy (FixedHeapSize(33554432))
===== DaCapo lusearch starting =====
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8207/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8207/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8223/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8239/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8239/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8223/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8223/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8255/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::plan::generational::global] Nursery GC
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8239/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8239/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8344/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8378/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8378/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8394/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8362/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8410/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8426/8192 pages)
[2025-08-28T06:35:48Z INFO mmtk::util::heap::gc_trigger] [POLL] nursery: Triggering collection (8442/8192 pages)
#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x00007efd366dbc58, pid=54101, tid=54110
#
# JRE version: OpenJDK Runtime Environment (11.0.19) (fastdebug build 11.0.19-internal+0-adhoc.runner.openjdk)
# Java VM: OpenJDK 64-Bit Server VM (fastdebug 11.0.19-internal+0-adhoc.runner.openjdk, mixed mode, tiered, compressed oops, third-party gc, linux-amd64)
# Problematic frame:
# C [libmmtk_openjdk.so+0x2dbc58] mmtk_openjdk::abi::OopDesc::size::haa91206576c0646a+0x18
#
# Core dump will be written. Default location: Core dumps may be processed with "/lib/systemd/systemd-coredump %P %u %g %s %t 9223372036854775808 %h %d" (or dumping to /home/runner/work/mmtk-core/mmtk-core/mmtk-openjdk/core.54101)
#
# An error report file with more information is saved as:
# /home/runner/work/mmtk-core/mmtk-core/mmtk-openjdk/hs_err_pid54101.log
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#
Current thread is 54110
Dumping core ...