RFR: 8369505: jhsdb jstack --mixed cannot handle continuation stub on Linux [v5]

[Yasumasa Suenaga]

> I tried to get mixed thread dump of the application which runs virtual threads (see [Test.java on JBS](https://bugs.openjdk.org/secure/attachment/116453/Test.java)) via `jhsdb jstack --mixed`, then I got following message:
> 
> 
> sun.jvm.hotspot.utilities.AssertionFailure: must have non-zero frame size
>         at jdk.hotspot.agent/sun.jvm.hotspot.utilities.Assert.that(Assert.java:32)
>         at jdk.hotspot.agent/sun.jvm.hotspot.runtime.x86.X86Frame.senderForCompiledFrame(X86Frame.java:374)
>         at jdk.hotspot.agent/sun.jvm.hotspot.runtime.x86.X86Frame.sender(X86Frame.java:273)
>         at jdk.hotspot.agent/sun.jvm.hotspot.runtime.Frame.sender(Frame.java:225)
>         at jdk.hotspot.agent/sun.jvm.hotspot.runtime.Frame.realSender(Frame.java:230)
>         at jdk.hotspot.agent/sun.jvm.hotspot.runtime.VFrame.sender(VFrame.java:120)
>         at jdk.hotspot.agent/sun.jvm.hotspot.runtime.VFrame.javaSender(VFrame.java:150)
>         at jdk.hotspot.agent/sun.jvm.hotspot.tools.PStack.initJFrameCache(PStack.java:224)
>         at jdk.hotspot.agent/sun.jvm.hotspot.tools.PStack.run(PStack.java:73)
>         at jdk.hotspot.agent/sun.jvm.hotspot.tools.PStack.run(PStack.java:65)
>         at jdk.hotspot.agent/sun.jvm.hotspot.tools.PStack.run(PStack.java:60)
>         at jdk.hotspot.agent/sun.jvm.hotspot.tools.JStack.run(JStack.java:67)
>         at jdk.hotspot.agent/sun.jvm.hotspot.tools.Tool.startInternal(Tool.java:278)
>         at jdk.hotspot.agent/sun.jvm.hotspot.tools.Tool.start(Tool.java:241)
>         at jdk.hotspot.agent/sun.jvm.hotspot.tools.Tool.execute(Tool.java:134)
>         at jdk.hotspot.agent/sun.jvm.hotspot.tools.JStack.runWithArgs(JStack.java:90)
>         at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.runJSTACK(SALauncher.java:306)
>         at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.main(SALauncher.java:507)
> 
> 
> And also I got following (strange) stacks which causes `AssersionFailure` in above:
> 
> 
> ----------------- 70094 -----------------
> "ForkJoinPool-1-worker-4" #32 daemon prio=5 tid=0x00007f8f5c371660 nid=70094 runnable [0x00007f8f406d9000]
>    java.lang.Thread.State: RUNNABLE
>    JavaThread state: _thread_in_native
> 0x00007f8f64658462 __syscall_cancel_arch + 0x32
> 0x00007f8f6464c75c __internal_syscall_cancel + 0x5c
> 0x00007f8f646a8c37 __GI___nanosleep + 0x17
> 0x00007f8f646bb14e __sleep + 0x3e
> 0x00007f8f4b3a8e1e <nep_invoker_blob>
> 0x00007f8f4b33fe48 * java.lang.invoke.LambdaForm$MH+0x000000000c047000.invoke(java.lang.Object, long, int) bci:10 (Interpreted frame)
> 0x00007f8f4b33fe48...

Yasumasa Suenaga has updated the pull request incrementally with one additional commit since the last revision:

  Apply changes to RISC-V code

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/27728/files
  - new: https://git.openjdk.org/jdk/pull/27728/files/915fca8d..57294d7c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27728&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27728&range=03-04

  Stats: 18 lines in 2 files changed: 16 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/27728.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27728/head:pull/27728

PR: https://git.openjdk.org/jdk/pull/27728