RFR: 8344935: [ubsan]: javaThread.hpp:1241:52: runtime error: load of value 9831830, which is not a valid value for type 'freeze_result' [v3]

[David Holmes]

On Tue, 26 Nov 2024 13:44:19 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

>> Seems we miss initialization of  _last_freeze_fail_result in the  JavaThread constructor, this should be added.
>> Causes otherwise ubsan issues in the test  java/lang/Thread/virtual/MonitorEnterExit.java#Xcomp-TieredStopAtLevel1-LM_LEGACY 
>> 
>> /priv/jenkins/client-home/workspace/openjdk-jdk-weekly-linux_x86_64-opt/jdk/src/hotspot/share/runtime/javaThread.hpp:1241:52: runtime error: load of value 9831830, which is not a valid value for type 'freeze_result'
>>     #0 0x7f5edef378eb in JavaThread::last_freeze_fail_result() src/hotspot/share/runtime/javaThread.hpp:1241
>>     #1 0x7f5edef378eb in JVM_VirtualThreadPinnedEvent src/hotspot/share/prims/jvm.cpp:3805
>
> Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:
> 
>   remove added state, add assert

Seems reasonable but I'm by no means a freeze/thaw expert. I'd really like @pchilano to review this but he won't be back until Monday 2nd December.

Thanks

src/hotspot/share/runtime/continuationFreezeThaw.cpp line 1684:

> 1682: }
> 1683: 
> 1684: static freeze_result preempt_epilog(JavaThread* thread, ContinuationWrapper& cont, freeze_result res, frame& old_last_frame) {

If `thread` is always the current thread, please name it `current`.

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PR Review: https://git.openjdk.org/jdk/pull/22361#pullrequestreview-2463986936
PR Review Comment: https://git.openjdk.org/jdk/pull/22361#discussion_r1859997608