Increment counter correctly in FFI Upcall on Z

[dchopra001]

When getArgPointer is invoked while an upcall is performed the gprIndex must be incremented if hidden parameters have to be accounted for. This commit implements the suggested change.

Fixes: #16214

Signed-off-by: Dhruv Chopra Dhruv.C.Chopra@ibm.com

[dchopra001]

Tagging @r30shah for review.

@ChengJin01 FYI

[r30shah]

Looks good to me. We should update comment to reflect that, for the complex return type GPR2 contains address of the return value buffer.

[r30shah]

@dchopra001 I would assume we you have verified the changes with FFI tests, right?
@joransiu Can you please review and merge this change?

[dchopra001]

@dchopra001 I would assume we you have verified the changes with FFI tests, right?

Yes, all the tests in TestUpcallStack.java now pass from my local testing.

@ChengJin01 is there any PR testing we can run to verify the change? Or alternatively did you want to also verify if this fixes the issue on Z?

[ChengJin01]

@ChengJin01 is there any PR testing we can run to verify the change? Or alternatively did you want to also verify if this fixes the issue on Z?

Please make sure the following upcall specific Jtreg test suites at https://github.com/ibmruntimes/openj9-openjdk-jdk19/tree/openj9/test/jdk/java/foreign pass without any issue given the problem here was captured by Jtreg test suites.

https://github.com/ibmruntimes/openj9-openjdk-jdk19/blob/openj9/test/jdk/java/foreign/TestUpcallScope.java
https://github.com/ibmruntimes/openj9-openjdk-jdk19/blob/openj9/test/jdk/java/foreign/TestUpcallAsync.java
https://github.com/ibmruntimes/openj9-openjdk-jdk19/blob/openj9/test/jdk/java/foreign/TestUpcallHighArity.java
https://github.com/ibmruntimes/openj9-openjdk-jdk19/blob/openj9/test/jdk/java/foreign/TestUpcallScope.java
https://github.com/ibmruntimes/openj9-openjdk-jdk19/blob/openj9/test/jdk/java/foreign/TestUpcallStructScope.java

[dchopra001]

Please make sure the following upcall specific Jtreg test suites at https://github.com/ibmruntimes/openj9-openjdk-jdk19/tree/openj9/test/jdk/java/foreign pass without any issue given the problem here was captured by Jtreg test suites.

I ran each of the listed tests twice and saw no failures. So I think we should be good to merge this.

[joransiu]

We should update comment to reflect that, for the complex return type GPR2 contains address of the return value buffer.

@dchopra001 : Do you want to update the comment as per @r30shah's suggestion?

[dchopra001]

@dchopra001 : Do you want to update the comment as per @r30shah's suggestion?

Sorry forgot to address that. The comments should be there now in de300b8

[r30shah]

LGTM, good to merge.

[joransiu]

jenkins test sanity zlinux jdk19