8354426: [ubsan] applying non-zero offset 34359738368 to null pointer in CompressedKlassPointers::encoding_range_end

[MBaesken]

When running with ubsan enabled binaries on AIX, the HS jtreg test gc/epsilon/TestClasses (and some other tests too) show the following issue :

/srcdir/jdk/src/hotspot/share/oops/compressedKlass.inline.hpp:98:16: runtime error: applying non-zero offset 34359738368 to null pointer
    #0 0x90000001185d7ec in CompressedKlassPointers::encoding_range_end() make/hotspot/src/hotspot/share/oops/compressedKlass.inline.hpp:98
    #1 0x90000001185d7ec in CompressedKlassPointers::print_mode(outputStream*) make/hotspot/src/hotspot/share/oops/compressedKlass.cpp:299
    #2 0x900000012b6eb90 in Metaspace::global_initialize() make/hotspot/src/hotspot/share/memory/metaspace.cpp:847
    #3 0x900000012b6d7d8 in universe_init() make/hotspot/src/hotspot/share/memory/universe.cpp:887
    #4 0x900000012c3aa58 in init_globals() make/hotspot/src/hotspot/share/runtime/init.cpp:132
    #5 0x900000012c6af7c in Threads::create_vm(JavaVMInitArgs*, bool*) make/hotspot/src/hotspot/share/runtime/threads.cpp:576
    #6 0x900000012cb0548 in JNI_CreateJavaVM_inner(JavaVM_**, void**, void*) make/hotspot/src/hotspot/share/prims/jni.cpp:3587
    #7 0x900000012cb0548 in JNI_CreateJavaVM make/hotspot/src/hotspot/share/prims/jni.cpp:3678

Seems we add to a base (== nullptr) some offset which is reported as undefined behavior.
On other OS the base might be different so we do not see it there.

---

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Issue

• JDK-8354426: [ubsan] applying non-zero offset 34359738368 to null pointer in CompressedKlassPointers::encoding_range_end (Bug - P4)

Reviewers

• Martin Doerr (@TheRealMDoerr - Reviewer)
• Joachim Kern (@JoKern65 - Committer)

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[bridgekeeper]

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

[openjdk]

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

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

8354426: [ubsan] applying non-zero offset 34359738368 to null pointer in CompressedKlassPointers::encoding_range_end

Reviewed-by: mdoerr, jkern

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At the time when this comment was updated there had been 11 new commits pushed to the master branch:

• 44245f3: 8354215: Clean up Loom support after 32-bit x86 removal
• 337dacd: 8354310: JFR: Inconsistent metadata in ZPageAllocation
• 2595c47: 8354231: x86: Purge FPU support from (Macro)Assembler after 32-bit x86 removal
• ... and 8 more: https://git.openjdk.org/jdk/compare/e604bb9e9412310d6d63da0b0f475f9da54ff244...master

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

• hotspot

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[mlbridge]

Webrevs

• 00: Full (0b1f2d42)

[TheRealMDoerr]

LGTM.

[JoKern65]

LGTM too

[MBaesken]

Thanks for the reviews !

/integrate

[openjdk]

Going to push as commit cf27a42.
Since your change was applied there have been 11 commits pushed to the master branch:

• 44245f3: 8354215: Clean up Loom support after 32-bit x86 removal
• 337dacd: 8354310: JFR: Inconsistent metadata in ZPageAllocation
• 2595c47: 8354231: x86: Purge FPU support from (Macro)Assembler after 32-bit x86 removal
• ... and 8 more: https://git.openjdk.org/jdk/compare/e604bb9e9412310d6d63da0b0f475f9da54ff244...master

Your commit was automatically rebased without conflicts.

[openjdk]

@MBaesken Pushed as commit cf27a42.

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