8361536: [s390x] Saving return_pc at wrong offset

[offamitkumar]

Fixes the bug where return pc was stored at a wrong offset, which causes issue with java abi.

Issue appeared in #26004, see the comment: #26004 (comment).

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8361536: [s390x] Saving return_pc at wrong offset (Enhancement - P3)

Reviewers

• Lutz Schmidt (@RealLucy - Reviewer) 🔄 Re-review required (review applies to e945e046)
• Martin Doerr (@TheRealMDoerr - Reviewer) 🔄 Re-review required (review applies to e945e046)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/26209/head:pull/26209
$ git checkout pull/26209

Update a local copy of the PR:
$ git checkout pull/26209
$ git pull https://git.openjdk.org/jdk.git pull/26209/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 26209

View PR using the GUI difftool:
$ git pr show -t 26209

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/26209.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back amitkumar! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

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• hotspot-compiler

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[RealLucy]

LGTM.
Thanks for fixing.

[offamitkumar]

Fast debug build was fine, but release build crashed with this error:

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x000003fffd16b19e, pid=281849, tid=281855
#
# JRE version: OpenJDK Runtime Environment (26.0) (build 26-internal-adhoc.amit.jdk)
# Java VM: OpenJDK 64-Bit Server VM (26-internal-adhoc.amit.jdk, mixed mode, tiered, compressed oops, compressed class ptrs, g1 gc, linux-s390x)
# Problematic frame:
# V  [libjvm.so+0x66b19e]  HandleMark::~HandleMark()+0x1e
#
# Core dump will be written. Default location: Core dumps may be processed with "/usr/share/apport/apport -p%p -s%s -c%c -d%d -P%P -u%u -g%g -F%F -- %E" (or dumping to /home/amit/jdk/core.281849)
#
# If you would like to submit a bug report, please visit:
#   https://bugreport.java.com/bugreport/crash.jsp
#

stack trace:

Stack: [0x000003fffc900000,0x000003fffca00000],  sp=0x000003fffc9fca40,  free space=1010k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x66b19e]  HandleMark::~HandleMark()+0x1e  (handles.inline.hpp:88)
V  [libjvm.so+0xc1a038]  Threads::create_vm(JavaVMInitArgs*, bool*)+0x528  (threads.cpp:905)
V  [libjvm.so+0x799e9a]  JNI_CreateJavaVM+0x7a  (jni.cpp:3589)
C  [libjli.so+0x40e0]  JavaMain+0xa0  (java.c:1506)
C  [libjli.so+0x8170]  ThreadJavaMain+0x20  (java_md.c:646)

This commit (e945e04) seems to be faulty.

[TheRealMDoerr]

We're not really saving space. We just use less of the caller allocated stack space which is still as large as before.
But the change looks good and should make the stack walking code happy, because it can find the return_pc where it is expected, now.

[mlbridge]

Webrevs

• 00: Full (f01c0e4f)

[offamitkumar]

@TheRealMDoerr I need reapproval. Can you provide one ? Thanks.