RFR: 8369506: Bytecode rewriting causes Java heap corruption on AArch64 [v3]

[Aleksey Shipilev]

On Wed, 15 Oct 2025 14:54:36 GMT, Justin King <jcking at openjdk.org> wrote:

>> Fix JDK-8369506 by adding `STLR` when updating the bytecode. Additionally I added a quick debug only check which verifies the field offset we get from `ResolvedFieldEntry` in `TemplateTable::fast_*` will not clobber the header or Klass pointer. The added `STLR`, a long with the already existing `DMB ISHLD` in `InterpreterMacroAssembler::load_field_entry`, guarantees that the fully filled out `ResolvedFieldEntry` is observable if the patched bytecode is observable. We do not need to add `LDAR` for bytecode loading or `LDAR` in `TemplateTable::fast_*` for that reason. If another observer happens to observe a `0` field offset, its guaranteed then that they will also observe the non-patched bytecode which will ultimately end up doing the resolution again, which is okay.
>
> Justin King has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains five additional commits since the last revision:
> 
>  - Merge branch 'openjdk:master' into aarch64-rewrite-bytecodes
>  - Suggestions from shipilev
>    
>    Signed-off-by: Justin King <jcking at google.com>
>  - Remove trailing whitespace added by Github
>    
>    Signed-off-by: Justin King <jcking at google.com>
>  - Update src/hotspot/cpu/aarch64/templateTable_aarch64.cpp
>    
>    Co-authored-by: Andrew Haley <aph-open at littlepinkcloud.com>
>  - JDK-8369506: Bytecode rewriting causes Java heap corruption on AArch64
>    
>    Signed-off-by: Justin King <jcking at google.com>

Marked as reviewed by shade (Reviewer).

Linux AArch64 server fastdebug, `make test TEST=all` has no new problems here.

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PR Review: https://git.openjdk.org/jdk/pull/27748#pullrequestreview-3341755373
PR Comment: https://git.openjdk.org/jdk/pull/27748#issuecomment-3407744620