RFR: 8374482: SA does not handle signal handler frame in mixed jstack [v2]

[Yasumasa Suenaga]

On Fri, 9 Jan 2026 20:07:41 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

>> Yasumasa Suenaga has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
>> 
>>  - Merge remote-tracking branch 'origin/master' into jhsdb-jstack-sighandler
>>  - Fix
>>  - 8374482: SA does not handle signal handler frame in mixed jstack
>
> src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/amd64/LinuxAMD64CFrame.java line 217:
> 
>> 215: 
>> 216:      var sym = closestSymbolToPC();
>> 217:      if (sym != null && sym.getName().equals("<signal handler called>")) {
> 
> You are using "<signal handler called>" in both C and java code. I think this should at least be called out in comments at each location so the readers knows they have to be kept in sync.

I added comments in both LinuxAMD64CFrame.java and symtab.c .

> src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/linux/amd64/LinuxAMD64ThreadContext.java line 49:
> 
>> 47: 
>> 48:   public static Address getRegFromSignalTrampoline(Address sp, int index) {
>> 49:     // ucontext_t locates at top of stack.
> 
> Did you mean "is located"?

Thank you! Fixed.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/29023#discussion_r2678162496
PR Review Comment: https://git.openjdk.org/jdk/pull/29023#discussion_r2678162808