RFR: 8293339: vm/jvmti/StopThread/stop001/stop00103 crashes with SIGSEGV in Continuation::is_continuation_mounted

[Serguei Spitsyn]

I was not able to reproduce this issue in thousands of mach5 runs on multiple platforms. However, the root cause seems to be pretty simple. A JvmtiVTMSTransitionDisabler needs to be added to make the JVM TI StopThread function to be VTMS (Virtual Thread Mount state) transition safe.

So the fix is a one-liner:

diff --git a/src/hotspot/share/prims/jvmtiEnv.cpp b/src/hotspot/share/prims/jvmtiEnv.cpp
index a9efe01c92e..f5e9176230a 100644
--- a/src/hotspot/share/prims/jvmtiEnv.cpp
+++ b/src/hotspot/share/prims/jvmtiEnv.cpp
@@ -1182,6 +1182,8 @@ JvmtiEnv::ResumeAllVirtualThreads(jint except_count, const jthread* except_list)
 jvmtiError
 JvmtiEnv::StopThread(jthread thread, jobject exception) {
   JavaThread* current_thread = JavaThread::current();
+
+  JvmtiVTMSTransitionDisabler disabler;
   ThreadsListHandle tlh(current_thread);
   JavaThread* java_thread = NULL;
   oop thread_oop = NULL;

-------------

Commit messages:
 - 8293339: vm/jvmti/StopThread/stop001/stop00103 crashes with SIGSEGV in Continuation::is_continuation_mounted

Changes: https://git.openjdk.org/jdk/pull/10235/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10235&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8293339
  Stats: 2 lines in 1 file changed: 2 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/10235.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10235/head:pull/10235

PR: https://git.openjdk.org/jdk/pull/10235