[lworld] RFR: 8371604: [lworld] SIGSEGV in InlineKlass::is_payload_marked_as_null [v2]

[Coleen Phillimore]

On Fri, 21 Nov 2025 15:52:48 GMT, Paul Hübner <phubner at openjdk.org> wrote:

>> Hi all,
>> 
>> This patch fixes several `int` overflows relating to flat array element loads/stores. 
>> I've included some gtests that address a subset of these changes.  We should test flat arrays larger than 16GB in size, which is not something we can feasibly do in our tier1 jtreg tests. I've filed [JDK-8372261](https://bugs.openjdk.org/browse/JDK-8372261) as a follow-up RFE to investigate this.
>> 
>> Testing: tiers 1-4, [`LocalityCheck.java`](https://bugs.openjdk.org/secure/attachment/117136/LocalityCheck.java) run locally 100 times.
>
> Paul Hübner has updated the pull request incrementally with one additional commit since the last revision:
> 
>   C1 changes

This looks good. Did you have a jvmci change still?

src/hotspot/share/oops/flatArrayOop.inline.hpp line 42:

> 40: 
> 41:   address addr = (address) base();
> 42:   addr += (index << Klass::layout_helper_log2_element_size(lh));

Because index is an int, this could go negative right?

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Marked as reviewed by coleenp (Committer).

PR Review: https://git.openjdk.org/valhalla/pull/1752#pullrequestreview-3493388550
PR Review Comment: https://git.openjdk.org/valhalla/pull/1752#discussion_r2550229139