When running jtreg test jdk/jfr/startupargs/TestStartDuration.java
with ubsan-enabled binaries, the following issue has been observed on
linuxaarch64 :

 stderr: [/priv/jenkins/client-home/workspace/openjdk-jdk-weekly-linux_aarch64-opt/jdk/src/hotspot/share/jfr/support/jfrThreadLocal.hpp:348:12: runtime error: load of value 108, which is not a valid value for type 'bool'
    #0 0xffff89a2b2a4 in JfrThreadLocal::in_sampling_critical_section() const src/hotspot/share/jfr/support/jfrThreadLocal.hpp:348
    #1 0xffff89a2b2a4 in build_from_context src/hotspot/share/jfr/periodic/sampling/jfrSampleRequest.cpp:237
    #2 0xffff89a2b2a4 in JfrSampleRequestBuilder::build_java_sample_request(void const*, JfrThreadLocal*, JavaThread*) src/hotspot/share/jfr/periodic/sampling/jfrSampleRequest.cpp:302
    #3 0xffff89a66080 in OSThreadSampler::do_task(SuspendedThreadTaskContext const&) src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:290
    #4 0xffff8a8800e8 in SuspendedThreadTask::internal_do_task() src/hotspot/os/posix/signals_posix.cpp:1848
    #5 0xffff89a642b8 in SuspendedThreadTask::run() src/hotspot/share/runtime/suspendedThreadTask.hpp:48
    #6 0xffff89a642b8 in OSThreadSampler::request_sample() src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:281
    #7 0xffff89a642b8 in JfrSamplerThread::sample_java_thread(JavaThread*) src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:304
    #8 0xffff89a64e34 in JfrSamplerThread::sample_java_thread(JavaThread*) src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:222
    #9 0xffff89a64e34 in JfrSamplerThread::task_stacktrace(JfrSampleRequestType, JavaThread**) src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:253
    #10 0xffff89a64e34 in JfrSamplerThread::run() src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:195
    #11 0xffff8aa9b260 in Thread::call_run() src/hotspot/share/runtime/thread.cpp:243
    #12 0xffff8a33e854 in thread_native_entry src/hotspot/os/linux/os_linux.cpp:868
    #13 0xffff8dcc2694 in start_thread (/lib64/libc.so.6+0x80694)
    #14 0xffff8dd2cbd8 in thread_start (/lib64/libc.so.6+0xeabd8)

Seems this is rather new, might be related to JDK-8352251 ?