[lworld] Integrated: 8313667: [lworld] XBarrierSetC2::clone_at_expansion() uses wrong array copy stub for cloning flat primitive type arrays

[Christian Hagedorn]

On Tue, 5 Sep 2023 14:01:09 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

> The singlegen ZGC version of `XBarrierSetC2::clone_at_expansion()` uses the wrong array copy stub for flat primitive type arrays when expanding an `ArrayCopyNode` for cloning. It wrongly treats a flat array of primitive types as flat array of oop pointers. This leads to intermittent wrong executions and crashes in ZGC because we are interpreting primitive values as oops.
> 
> The fix is straight forward to special case flat arrays in `XBarrierSetC2::clone_at_expansion()` similar to what we already do in `ZBarrierSetC2::clone_at_expansion()`:
> https://github.com/openjdk/valhalla/blob/3b4cc5fdb038a7363e5ac8a704adacd70701c1ff/src/hotspot/share/gc/z/c2/zBarrierSetC2.cpp#L457-L465
> 
> Thanks,
> Christian

This pull request has now been integrated.

Changeset: 261a0457
Author:    Christian Hagedorn <chagedorn at openjdk.org>
Committer: Tobias Hartmann <thartmann at openjdk.org>
URL:       https://git.openjdk.org/valhalla/commit/261a0457ec4dbb39427ad9b9e5e12138e4eb7e2b
Stats:     98 lines in 3 files changed: 96 ins; 0 del; 2 mod

8313667: [lworld] XBarrierSetC2::clone_at_expansion() uses wrong array copy stub for cloning flat primitive type arrays

Reviewed-by: thartmann

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PR: https://git.openjdk.org/valhalla/pull/924