8360942: [ubsan] aotCache tests trigger runtime error: applying non-zero offset 16 to null pointer in CodeBlob::relocation_end()

[vnkozlov]

CodeBlob::relocation_size() is calculated as (_mutable_data + _relocation_size - _mutable_data). CodeBlob::relocation_size() is called during AOT code loading before we allocate space for mutable data (the size is used to find how big space should be allocated). The expression at that point is (NULL + _relocation_size - NULL) which returns correct result. But we should just return _relocation_size which is recorded anyway in AOT data.

Added missing _mutable_data = blob_end(); initialization when we restore AOT code blob.

Fixed embarrassing typo in asserts.

Tested: tier1-6,8,10,xcomp,stress

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Issue

• JDK-8360942: [ubsan] aotCache tests trigger runtime error: applying non-zero offset 16 to null pointer in CodeBlob::relocation_end() (Bug - P4)

Reviewers

• Andrew Dinn (@adinn - Reviewer)
• Matthias Baesken (@MBaesken - Reviewer)

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

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8360942: [ubsan] aotCache tests trigger runtime error: applying non-zero offset 16 to null pointer in CodeBlob::relocation_end()

Reviewed-by: adinn, mbaesken

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At the time when this comment was updated there had been 9 new commits pushed to the master branch:

• 0bd2f9c: 8361445: javac crashes on unresolvable constant in @SuppressWarnings
• 27e6a4d: 8344548: Incorrect StartAggressiveSweepingAt doc for segmented code cache
• 1934bd8: 8361481: Flexible Constructor Bodies generates a compilation error when compiling a user supplied java.lang.Object class
• ... and 6 more: https://git.openjdk.org/jdk/compare/197fde5363e314de7cd6090ecd77521f3a90c56d...master

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[mlbridge]

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• 00: Full (b32d6176)

[vnkozlov]

@MBaesken, please verify that is passing ubsan testing now.

[adinn]

Looks good.

[MBaesken]

please verify that is passing ubsan testing now.

Hi Vladimir, I do not see the mentioned ubsan error (codeBlob.hpp:235:97: runtime error: applying non-zero offset 16 to null pointer) after your patch was added!