8279664: riscv: JFR crashes at 0x0

[zhengxiaolinX]

Hi team,

This is a preview fix for the JFR-related crash - maybe the comment in this patch should be polished.
TIL that complex problems often result from seemingly negligible changes :-)
I need to cautiously test this change, though it seems no harm, to guarantee that it is safe and to ensure the problem is gone so please stay a little tuned.

---

Update:

1. Overnight JFR testing reveals no error, seems fixed.
2. test/hotspot/jtreg on the board reveals no error until now - still testing, but I think it is safe.

---

Thanks,
Xiaolin

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed

Issue

• JDK-8279664: riscv: JFR crashes at 0x0

Reviewers

• Yadong Wang (@yadongw - Committer) ⚠️ Review applies to 7c7a142
• Fei Yang (@RealFYang - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/riscv-port pull/49/head:pull/49
$ git checkout pull/49

Update a local copy of the PR:
$ git checkout pull/49
$ git pull https://git.openjdk.java.net/riscv-port pull/49/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 49

View PR using the GUI difftool:
$ git pr show -t 49

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/riscv-port/pull/49.diff

[bridgekeeper]

👋 Welcome back xlinzheng! A progress list of the required criteria for merging this PR into riscv-port will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[mlbridge]

Webrevs

• 02: Full - Incremental (dd8b495e)
• 01: Full - Incremental (9ae33721)
• 00: Full (7c7a1426)

[yadongw]

@zhengxiaolinX Nice catch. In fact, we fixed a similar bug before, and unfortunately missed here.

[RealFYang]

Great catch. This aligns with function "enter()" which creates stack frames. Looks good.

[RealFYang]

I see JFR works quite stable with some non-trivial benchmark workload. So good to go. Thanks.

[openjdk]

@zhengxiaolinX 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:

8279664: riscv: JFR crashes at 0x0

Reviewed-by: yadongwang, fyang

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 16 new commits pushed to the riscv-port branch:

• 414c580: Merge branch 'master' into riscv-port
• 35ee0f3: 8258814: Compilation logging crashes for thread suspension / debugging tests
• 293fb46: 8280413: ProblemList jdk/jfr/event/oldobject/TestLargeRootSet.java on all X64 platforms
• 2426d58: 8278472: Invalid value set to CANDIDATEFORM structure
• 02390c7: 8279282: [vectorapi] Matcher::supports_vector_comparison_unsigned is not needed on x86
• 3419ff7: 8277535: Remove redundant Stream.distinct()/sorted() steps
• d48279b: 8279009: CDS crashes when the source of an InstanceKlass is NULL
• 9636502: 8279008: G1: Calculate BOT threshold on-the-fly during Object Copy phase
• 0ea2b39: 8280363: Minor correction of ALPN specification in SSLParameters
• ec8b6ac: 8234682: The order of @param in the generated docs should match the method signature
• ... and 6 more: https://git.openjdk.java.net/riscv-port/compare/3f82c394ed968c914a26b6ba12268da86ddc6869...riscv-port

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.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change. Possible candidates are the reviewers of this PR (@yadongw, @RealFYang) but any other Committer may sponsor as well.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[zhengxiaolinX]

Thanks for the fast reviews, team!

/integrate

[RealFYang]

/sponsor

[openjdk]

@zhengxiaolinX
Your change (at version dd8b495) is now ready to be sponsored by a Committer.

[openjdk]

Going to push as commit 29384f9.
Since your change was applied there have been 16 commits pushed to the riscv-port branch:

• 414c580: Merge branch 'master' into riscv-port
• 35ee0f3: 8258814: Compilation logging crashes for thread suspension / debugging tests
• 293fb46: 8280413: ProblemList jdk/jfr/event/oldobject/TestLargeRootSet.java on all X64 platforms
• 2426d58: 8278472: Invalid value set to CANDIDATEFORM structure
• 02390c7: 8279282: [vectorapi] Matcher::supports_vector_comparison_unsigned is not needed on x86
• 3419ff7: 8277535: Remove redundant Stream.distinct()/sorted() steps
• d48279b: 8279009: CDS crashes when the source of an InstanceKlass is NULL
• 9636502: 8279008: G1: Calculate BOT threshold on-the-fly during Object Copy phase
• 0ea2b39: 8280363: Minor correction of ALPN specification in SSLParameters
• ec8b6ac: 8234682: The order of @param in the generated docs should match the method signature
• ... and 6 more: https://git.openjdk.java.net/riscv-port/compare/3f82c394ed968c914a26b6ba12268da86ddc6869...riscv-port

Your commit was automatically rebased without conflicts.

[openjdk]

@RealFYang @zhengxiaolinX Pushed as commit 29384f9.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.