RFR: 8339307: jhsdb jstack could not trace FFM upcall frame

[Jorn Vernee]

On Fri, 6 Sep 2024 09:31:45 GMT, Yasumasa Suenaga <ysuenaga at openjdk.org> wrote:

> This PR is successor of #20789 . I got some comments in there, then I needed to fix in many pooints. And also I have to fix branch name to kick GHA automatically (#20789 is named with `pr/`, it meets the condition to skip GHA). Hence I've opened another PR for this JBS issue.
> 
> This PR has been updated with about topics since #20789:
> * Use `JavaFrameAnchor` instead of raw frame pointer to unwind frame of `UpcallStub`.
> * The change happens x86 (includes AMD64), aarch64, PPC64, RISC-V 64 only - s390 is out of scope because SA does not have s390 implementation.
>     * Only both AMD64 and aarch64 have tested on GHA.
> * Refactor testcase to meet expected condition certainly.

Looks great! Thanks for implementing the JFA-based stack walking.

Please wait for another review from someone more familiar with SA as well, before integrating.

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/ppc64/PPC64Frame.java line 326:

> 324: 
> 325:     var lastJavaFP = stub.getLastJavaFP(this); // This will be null
> 326:     var lastJavaSP = stub.getLastJavaSP(this);                              var lastJavaPC = stub.getLastJavaPC(this);

Suggestion:

    var lastJavaSP = stub.getLastJavaSP(this);
    var lastJavaPC = stub.getLastJavaPC(this);

test/hotspot/jtreg/serviceability/sa/libupcall.c line 2:

> 1: /*
> 2:  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

Suggestion:

 * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.

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Marked as reviewed by jvernee (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/20885#pullrequestreview-2286531642
PR Review Comment: https://git.openjdk.org/jdk/pull/20885#discussion_r1747290780
PR Review Comment: https://git.openjdk.org/jdk/pull/20885#discussion_r1747295233