When running on linux aarch64 with ubsan-enabled binaries, test
gc/logging/TestUnifiedLoggingSwitchStress.java
showed this issue :

/priv/jenkins/client-home/workspace/openjdk-jdk-weekly-linux_aarch64-opt/jdk/src/hotspot/share/gc/g1/g1CollectionSetCandidates.cpp:69:66: runtime error: division by zero
    #0 0xffffa4bc9f64 in G1CSetCandidateGroup::liveness() const src/hotspot/share/gc/g1/g1CollectionSetCandidates.cpp:69
    #1 0xffffa4be2868 in G1PrintRegionLivenessInfoClosure::log_cset_candidate_group_add_total(G1CSetCandidateGroup*, char const*) src/hotspot/share/gc/g1/g1ConcurrentMark.cpp:3113
    #2 0xffffa4be2e9c in G1PrintRegionLivenessInfoClosure::log_cset_candidate_groups() src/hotspot/share/gc/g1/g1ConcurrentMark.cpp:3163
    #3 0xffffa4be3430 in G1PrintRegionLivenessInfoClosure::~G1PrintRegionLivenessInfoClosure() src/hotspot/share/gc/g1/g1ConcurrentMark.cpp:3092
    #4 0xffffa4be3430 in G1PrintRegionLivenessInfoClosure::~G1PrintRegionLivenessInfoClosure() src/hotspot/share/gc/g1/g1ConcurrentMark.cpp:3082
    #5 0xffffa4cf84ac in G1Policy::record_concurrent_mark_cleanup_end(bool) src/hotspot/share/gc/g1/g1Policy.cpp:1317
    #6 0xffffa4be6d70 in G1ConcurrentMark::cleanup() src/hotspot/share/gc/g1/g1ConcurrentMark.cpp:1541
    #7 0xffffa4d48768 in VM_G1PauseConcurrent::doit() src/hotspot/share/gc/g1/g1VMOperations.cpp:154
    #8 0xffffa6266504 in VM_Operation::evaluate() src/hotspot/share/runtime/vmOperations.cpp:74
    #9 0xffffa62707f0 in VMThread::evaluate_operation(VM_Operation*) src/hotspot/share/runtime/vmThread.cpp:284
    #10 0xffffa6272550 in VMThread::inner_execute(VM_Operation*) src/hotspot/share/runtime/vmThread.cpp:421
    #11 0xffffa6272c70 in VMThread::loop() src/hotspot/share/runtime/vmThread.cpp:487
    #12 0xffffa6272d74 in VMThread::run() src/hotspot/share/runtime/vmThread.cpp:177
    #13 0xffffa60dbf20 in Thread::call_run() src/hotspot/share/runtime/thread.cpp:243
    #14 0xffffa597dc74 in thread_native_entry src/hotspot/os/linux/os_linux.cpp:868
    #15 0xffffa90d2b3c in start_thread (/lib64/libc.so.6+0x80b3c)
    #16 0xffffa913d158 in thread_start (/lib64/libc.so.6+0xeb158)

Seems this happens in the division
   return (size_t) ceil(((capacity - _reclaimable_bytes) * 100.0) / capacity);
at the end of G1CSetCandidateGroup::liveness() .