RFR: 8282191: Implementation of Foreign Function & Memory API (Preview) [v37]

[Maurizio Cimadamore]

On Wed, 4 May 2022 23:29:53 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

>> Good points. Regarding `ClassLoader` being null, I think we can still return something using the `BootLoader`'s `NativeLibraries` object - that would allow this method to be called internally. @mlchung Can you please confirm?
>> 
>> As for the caller sensitive having no real caller (e.g. because method is called directly from native code), I think we should add a check in `Reflection::ensureNativeAccess`. Few weeks ago I verified that adding such a check does not compromise upcall stub created via the Linker interface (e.g. a Java upcall might require to perform restricted operations - but those operation always happen inside the upcall MH, which is always associated with some class).
>
> Another option would be to treat calls to `ensureNativeAccess` with `null` caller class as coming from unnamed module.

Looking deeper, `System::loadLibrary` seems to search the boot loader libraries when invoked with a `null` caller class, so replicating that behavior should be safe.

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PR: https://git.openjdk.java.net/jdk/pull/7888