Integrated: 8277444: Data race between JvmtiClassFileReconstituter::copy_bytecodes and class linking

[Evgeny Astigeevich]

On Wed, 20 Aug 2025 15:36:14 GMT, Evgeny Astigeevich <eastigeevich at openjdk.org> wrote:

> There is a race between `JvmtiClassFileReconstituter::copy_bytecodes` and `InstanceKlass::link_class_impl`.  `InstanceKlass::link_class_impl` can be rewriting bytecodes. `JvmtiClassFileReconstituter::copy_bytecodes` will not restore them to the original ones because the flag `rewritten` is `false`. This will result in invalid bytecode.
> 
> This PR adds linking a class before the `copy_bytecodes` method is called.
> The PR also adds a regression test.
> 
> Tested fastdebug and release builds: Linux x86_64 and arm64
> - The reproducer from JDK-8277444 passed.
> - The regression test passed.
> - Tier1 - tier3 passed.

This pull request has now been integrated.

Changeset: 46ae1ee8
Author:    Evgeny Astigeevich <eastigeevich at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/46ae1ee87152742082e6047d0556944d7ae4567d
Stats:     187 lines in 3 files changed: 186 ins; 0 del; 1 mod

8277444: Data race between JvmtiClassFileReconstituter::copy_bytecodes and class linking

Reviewed-by: dholmes, amenkov, coleenp

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PR: https://git.openjdk.org/jdk/pull/26863