RFR: 8373110: jstack --mixed frames are broken on macOS after JDK-8371194

[Yasumasa Suenaga]

On Mon, 8 Dec 2025 20:37:04 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

>> [JDK-8371194](https://bugs.openjdk.org/browse/JDK-8371194) (PR #28284) has broken PStack (jstack --mixed) behavior on macOS. It affects both AMD64 and AArch64. See JBS for details.
>> 
>> This PR fixes it to implement `CFrame::toFrame`.
>
> macosx-aarch64 looks fine, but it looks like there is still an issue on macosx-x64. Stack traces are empty:
> 
> ```----------------- 29955 -----------------
> "Reference Handler" #15 daemon prio=10 tid=0x00007f94c0820010 nid=29955 waiting on condition [0x000070000e080000]
>    java.lang.Thread.State: RUNNABLE
>    JavaThread state: _thread_blocked
> 0x00007ff803c3b6f6		????????
> 
> Before this change you at least got a partial stack followed by the UnsupportedPlatformException.

@plummercj 

>  there is still an issue on macosx-x64. Stack traces are empty

Does it happen always? or intermittently?

> Before this change you at least got a partial stack followed by the UnsupportedPlatformException.

I'm not sure, but I guess jstack could not unwind frame at some point(s) due to unwind info like DWARF on Linux - jstack might not handle call frame because the symbol could not be resolved.

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PR Comment: https://git.openjdk.org/jdk/pull/28686#issuecomment-3629519426