8348384: RISC-V: Disable auto-enable Vector on buggy kernels

[robehn]

Hi please consider!

Linux kernels pre-6.9 can copy a dirty v-state during signal return path:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/riscv/kernel/signal.c?h=v6.13-rc1&id=c27fa53b858b4ee6552a719aa599c250cf98a586

We should not auto-enable vector with such kernel, as we must be able to receive signals during the execution of vector code.

Manual tested pre and post 6.9 as expected.

Thanks, Robbin

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Issue

• JDK-8348384: RISC-V: Disable auto-enable Vector on buggy kernels (Bug - P4)

Reviewers

• Hamlin Li (@Hamlin-Li - Reviewer) Review applies to d5d486a1
• Ludovic Henry (@luhenry - Committer) Review applies to d5d486a1
• Fei Yang (@RealFYang - Reviewer)

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8348384: RISC-V: Disable auto-enable Vector on buggy kernels

Reviewed-by: fyang, mli, luhenry

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• 70eec90: 8338303: Linux ppc64le with toolchain clang - detection failure in early JVM startup

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• 02: Full - Incremental (0b2e26c0)
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[Hamlin-Li]

Looks good.
Just a minor comment.

[robehn]

Looks good. Just a minor comment.

Thank you!

[robehn]

Thanks @luhenry !

[robehn]

I'll merge with #23291 and check for 6.8.5.

[robehn]

Merged and updated, using kernel_compare and 6.8.5.

[RealFYang]

Thanks for the update.

[robehn]

/integrate

[openjdk]

Going to push as commit 2537a05.
Since your change was applied there have been 16 commits pushed to the master branch:

• 46f48e4: 8348515: Add docs for -XX:AOT* options in java man pages
• 1916a77: 8346923: MetaspaceShared base calculation may cause overflow in align_up
• 21feef3: 8348239: SA does not know about DeoptimizeObjectsALotThread
• 8cc1304: 8287788: Implement a better allocator for downcalls
• 039e73f: 8346736: Java Security Standard Algorithm Names spec should include key algorithm names
• aba60a9: 8189441: Define algorithm names for keys derived from KeyAgreement
• 03106eb: 8344119: CUPSPrinter does not respect PostScript printer definition specification in case of reading ImageableArea values from PPD files
• ad01dfb: 8346920: Serial: Support allocation in old generation when heap is almost full
• 1d8ccb8: 8342465: Improve API documentation for java.lang.classfile
• 7d6055a: 8348429: Update cross-compilation devkits to Fedora 41/gcc 13.2
• ... and 6 more: https://git.openjdk.org/jdk/compare/a1fd5f4e88f52125eef4feea91a60641981177c1...master

Your commit was automatically rebased without conflicts.

[openjdk]

@robehn Pushed as commit 2537a05.

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