RFR: 8370176: Mixed mode jhsdb jstack cannot unwind call stack with -Xcomp [v2]

[Fei Yang]

On Fri, 24 Oct 2025 07:08:08 GMT, Yasumasa Suenaga <ysuenaga at openjdk.org> wrote:

>> Hi, I am just wondering if there is a workaround for these platforms. Or can we simply skip this when testing on them? Say, if this depends on the availability of pstack, maybe we can add check for that then. Otherwise, we may introduce test noise for people who use them.
>
> I could reproduce the problem not only Ubuntu 22.04 but also 23.04 . However it did not happen on Ubuntu 24.04 .
> According to your report, the problem would happen on AArch64, it implies the problem is not in DWARF parser only. (DWARF parser is only available on Linux AMD64 so far)
> 
> AFAICS stack unwinding would fail from the function in glibc (on Ubuntu 22.04 and 23.04 at least), so I suspect something wrong in glibc binary and/or behavior and/or compiler options on Ubuntu. but I'm not sure.
> 
> I checked glibc version from `gnu_get_libc_version()`. "2.37" is returned on Ubuntu 23.04, and "2.39" is returned on Ubuntu 24.04 . So I think it can be `gnu_get_libc_version()` with FFM at first of the test, then the test is skipped if it runs on glibc 2.38 or earlier. Is it ok?
> 
> I grep'ed test directory with "mixed", I found another tests (TestJhsdbJstackMixed.java, TestJhsdbJstackPrintVMLocks.java). I will add glibc check to them as another ticket if this solution is ok.

I am not sure about the glibc version as I don't know much about the differences among these distributions.
But it works for me if you want to fix all the affected tests in another PR. Thanks for considering that.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27885#discussion_r2460933106