RFR: 8277489: Rewrite JAAS UnixLoginModule with FFM [v5]

[Weijun Wang]

On Mon, 12 Jan 2026 11:37:17 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

>>> It's unfortunate that the FFM doesn't provide a good abstraction for passing `uint32_t`. Maybe we should implement an enhancement?
>> 
>> Indeed, the status quo with respect to unsigned values passed to downcalls is a bit suboptimal, esp. in certain ABIs where sign/zero extension is required. This is tracked here:
>> 
>> https://bugs.openjdk.org/browse/JDK-8336664
>> 
>> (apologies -- this link was already shared by @dmlloyd )
>
> Should we use the workaround I have proposed above until a better solution for [JDK-8336664](https://bugs.openjdk.org/browse/JDK-8336664) is available? Or are there other suggestions?

@TheRealMDoerr I haven't used your `calling_convention_requires_int_as_long` flag in my new commit. Can you investigate the approach in a different JBS issue?

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PR Review Comment: https://git.openjdk.org/jdk/pull/28931#discussion_r2688164522