On Fri, 29 Aug 2025 22:48:06 GMT, Evgeny Astigeevich <eastigeev...@openjdk.org> wrote:
>> There is a race between `JvmtiClassFileReconstituter::copy_bytecodes` and >> `InstanceKlass::link_class_impl`. `InstanceKlass::link_class_impl` can be >> rewriting bytecodes. `JvmtiClassFileReconstituter::copy_bytecodes` will not >> restore them to the original ones because the flag `rewritten` is `false`. >> This will result in invalid bytecode. >> >> This PR adds linking a class before the `copy_bytecodes` method is called. >> The PR also adds a regression test. >> >> Tested fastdebug and release builds: Linux x86_64 and arm64 >> - The reproducer from JDK-8277444 passed. >> - The regression test passed. >> - Tier1 - tier3 passed. > > Evgeny Astigeevich has updated the pull request with a new target base due to > a merge or a rebase. The incremental webrev excludes the unrelated changes > brought in by the merge/rebase. The pull request contains five additional > commits since the last revision: > > - Merge branch 'master' into JDK-8277444 > - Link classes before copy_bytecodes; Add regression test > - Symplify comments; Get JavaThread::current in variable > - Add missing include runtime/synchronizer.hpp > - 8277444: Race condition on Instrumentation.retransformClasses() and class > linking > The virtual thread test that is failing in this PR's GitHub actions job is > `java/lang/Thread/virtual/stress/GetStackTraceALotWhenBlocking#id0` > It looks like it's taking long to complete and that's causing the test > timeout. I recollect that this test failure was addressed some time back, so > this appears to be a new occurrence. In any case, this failure doesn't look > related to the changes in this PR because I see some other PRs having failed > with this same issue. I'll check and file an issue later today/tomorrow > (unless anyone else gets to it first). I've filed https://bugs.openjdk.org/browse/JDK-8366669 to track this failure. ------------- PR Comment: https://git.openjdk.org/jdk/pull/26863#issuecomment-3244555487
