8254874: ZGC: JNIHandleBlock verification failure in stack watermark processing

[stefank]

The cm03t001 test creates a local JNI handle in the prepare function. It later uses that handle from a callback function, from another thread. When the callback runs, ZGC applies a load barrier to that handle and self-heals it in the other threads stack. Later when that thread verifies its stack, during the start of its stack processing, it finds that the oop is unexpectedly not "bad".

It's invalid to send a local JNI handle over to another thread:
https://docs.oracle.com/en/java/javase/15/docs/specs/jni/design.html#global-and-local-references

So, my proposed fix is to convert the local handle to a global handle.

I've tested this with the reproducer in the bug report.

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Progress

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Testing

	Linux x64	Windows x64	macOS x64
Build	✔️ (5/5 passed)	✔️ (2/2 passed)	✔️ (2/2 passed)
Test (tier1)	✔️ (9/9 passed)	✔️ (9/9 passed)	✔️ (9/9 passed)

Issue

• JDK-8254874: ZGC: JNIHandleBlock verification failure in stack watermark processing

Reviewers

• Thomas Schatzl (@tschatzl - Reviewer)
• Chris Plummer (@plummercj - Reviewer)
• Serguei Spitsyn (@sspitsyn - Reviewer)
• Per Liden (@pliden - Reviewer)

Download

$ git fetch https://git.openjdk.java.net/jdk pull/701/head:pull/701
$ git checkout pull/701

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Webrevs

• 00: Full (91eefd1)

[stefank]

/label add hotspot-gc

[openjdk]

@stefank
The hotspot-gc label was successfully added.

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@stefank This change now passes all automated pre-integration checks.

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After integration, the commit message for the final commit will be:

8254874: ZGC: JNIHandleBlock verification failure in stack watermark processing

Reviewed-by: tschatzl, cjplummer, sspitsyn, pliden

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At the time when this comment was updated there had been 6 new commits pushed to the master branch:

• 0b3e6c5: 8194126: Regression automated Test '/open/test/jdk/javax/swing/JColorChooser/Test7194184.java' fails
• ce1aac1: 8028707: javax/swing/JComboBox/6236162/bug6236162.java fails on azure
• 83ea863: 8253559: The INDEX page should link to Serialized Form and Constant Values pages
• e66c6bb: 8254349: The TestNoScreenMenuBar test should be updated
• 402d01a: 8254795: Remove obsolete template files
• 07ec35e: 8254623: gc/g1/TestHumongousConcurrentStartUndo.java still fails sometimes

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

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[plummercj]

The changes look good. It is confusing however that klass is also a local variable in a few functions, hiding the static version from scope, but this is a pre-existing problem.

[sspitsyn]

Hi Stefan,
The fix looks good.
Thank you for catching this.
The test has 4 more static variables which are not used in the events handlers.
Thanks,
Serguei

[stefank]

Thanks for reviewing!

[stefank]

/integrate

[openjdk]

@stefank Since your change was applied there have been 13 commits pushed to the master branch:

• 98a395a: 8254880: ZGC: Let ZList iterators be alias templates
• 011dd0d: 8254824: SignalHandlerMark have no purpose
• 736e077: 8254178: Remove .hgignore
• 51a865d: 8254085: javax/swing/text/Caret/TestCaretPositionJTextPane.java failed with "RuntimeException: Wrong caret position"
• dd032b7: 8254798: Deprecate for removal an empty finalize() methods in java.desktop module
• 272bb5d: 8253455: Record Classes javax.lang.model changes
• c17d585: 8246774: implement Record Classes as a standard feature in Java
• 0b3e6c5: 8194126: Regression automated Test '/open/test/jdk/javax/swing/JColorChooser/Test7194184.java' fails
• ce1aac1: 8028707: javax/swing/JComboBox/6236162/bug6236162.java fails on azure
• 83ea863: 8253559: The INDEX page should link to Serialized Form and Constant Values pages
• ... and 3 more: https://git.openjdk.java.net/jdk/compare/0570cc10b579580f37b8978f2498459bdd4c870b...master

Your commit was automatically rebased without conflicts.

Pushed as commit 672f566.

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