8325074: ZGC fails assert(index == 0 || is_power_of_2(index)) failed: Incorrect load shift: 11

[xmas92]

ZBarrierSet::clone_obj_array incorrectly treats the payload of an ObjArray as [base, obj + size[. With non standard object alignment (ObjectAlignmentInBytes) there may be padding words at the end.

Change ZBarrierSet::clone_obj_array to instead use [base, base + length[ as the payload.

---

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Issue

• JDK-8325074: ZGC fails assert(index == 0 || is_power_of_2(index)) failed: Incorrect load shift: 11 (Bug - P2)

Reviewers

• Erik Österlund (@fisk - Reviewer)
• Stefan Karlsson (@stefank - Reviewer)
• Roberto Castañeda Lozano (@robcasloz - Reviewer)

Reviewing

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[bridgekeeper]

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[openjdk]

@xmas92 The following label will be automatically applied to this pull request:

• hotspot-gc

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[mlbridge]

Webrevs

• 00: Full (29ba6727)

[fisk]

Looks good.

[openjdk]

@xmas92 This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

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

8325074: ZGC fails assert(index == 0 || is_power_of_2(index)) failed: Incorrect load shift: 11

Reviewed-by: eosterlund, stefank, rcastanedalo

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 13 new commits pushed to the master branch:

• 1aae980: 8323994: gtest runner repeats test name for every single gtest assertion
• 810daf8: 8325910: Rename jnihelper.h
• 22e8181: 8325682: Rename nsk_strace.h
• b823fa4: 8325574: Shenandoah: Simplify and enhance reporting of requested GCs
• 09d4936: 8252136: Several methods in hotspot are missing "static"
• f6e2851: 8316340: (bf) Missing {@inheritdoc} for exception in MappedByteBuffer::compact
• 53878ee: 8325643: G1: Refactor G1FlushHumongousCandidateRemSets
• 130f429: 8325403: Add SystemGC JMH benchmarks
• 9c852df: 8318966: Some methods make promises about Java array element alignment that are too strong
• 737b4c5: 8323883: JFR AssertionError: Missing object ID 15101
• ... and 3 more: https://git.openjdk.org/jdk/compare/0c2def0e3eaa4925746158294f798d37d42c50f3...master

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.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[robcasloz]

The fix looks good. How did you confirm that it solves the issue (given the failure is intermittent with low frequency)? Would it be possible to complement the failing test case with another test that reproduces the issue more reliably?

[xmas92]

The fix looks good. How did you confirm that it solves the issue (given the failure is intermittent with low frequency)? Would it be possible to complement the failing test case with another test that reproduces the issue more reliably?

Running with #17864 reproduces this deterministically. As that change might require some more input (a more general change to heap invariant checking) we decided to split it out to an RFE and not as part of this bug fix.

[robcasloz]

Running with #17864 reproduces this deterministically. As that change might require some more input (a more general change to heap invariant checking) we decided to split it out to an RFE and not as part of this bug fix.

I see, great, thanks!

[xmas92]

Thanks for the reviews.
/integrate

[openjdk]

Going to push as commit 2705ed0.
Since your change was applied there have been 30 commits pushed to the master branch:

• 3d85103: 8316813: NMT: Using WhiteBox API, virtual memory tracking should also be stressed in JMH tests
• ba8db1f: 8325876: crashes in docker container tests on Linuxppc64le Power8 machines
• 18cea82: 8319801: Recursive lightweight locking: aarch64 implementation
• 9029bf6: 8316451: 6 java/lang/instrument/PremainClass tests ignore VM flags
• 99c9ae1: 8323664: java/awt/font/JNICheck/FreeTypeScalerJNICheck.java still fails with JNI warning on some Windows configurations
• 0fdfdf7: 8325983: Build failure after JDK-8324580
• 3b1062d: 8322239: [macos] a11y : java.lang.NullPointerException is thrown when focus is moved on the JTabbedPane
• 5a988a5: 8322750: Test "api/java_awt/interactive/SystemTrayTests.html" failed because A blue ball icon is added outside of the system tray
• a231706: 8324580: SIGFPE on THP initialization on kernels < 4.10
• 2564f0f: 8325906: Problemlist vmTestbase/vm/mlvm/meth/stress/compiler/deoptimize/Test.java#id1 until JDK-8320865 is fixed
• ... and 20 more: https://git.openjdk.org/jdk/compare/0c2def0e3eaa4925746158294f798d37d42c50f3...master

Your commit was automatically rebased without conflicts.

[openjdk]

@xmas92 Pushed as commit 2705ed0.

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