8385572: [PPC64] frame alignment assertion after JDK-6960970

[TheRealMDoerr]

The assertion should also permit deoptimized frames like interpreted frames. They also reach the assertion since JDK-6960970. (See stack trace in JBS issue.)
I've also implemented the missing ppc64 code from that issue. The serviceability/jvmti tests have passed.

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Issue

• JDK-8385572: [PPC64] frame alignment assertion after JDK-6960970 (Bug - P4)

Reviewers

• Amit Kumar (@offamitkumar - Committer)
• Matthias Baesken (@MBaesken - Reviewer)

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8385572: [PPC64] frame alignment assertion after JDK-6960970

Reviewed-by: amitkumar, mbaesken

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At the time when this comment was updated there had been 14 new commits pushed to the master branch:

• 163ab37: 8385628: Typo in jdk.attach comments
• 0a5221d: 8385627: Typo in JMXServiceURL.java: misssing
• 9ed5af9: 8385557: Shenandoah: Runtime calls from C2 stubs need to be relocatable
• ... and 11 more: https://git.openjdk.org/jdk/compare/2b618b4231c14ceee4d0affa39f90cdf6ed40e61...master

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[TheRealMDoerr]

@offamitkumar: This code should probably also be implemented for s390.

[TheRealMDoerr]

Thanks for the reviews!
/integrate

[openjdk]

Going to push as commit f823e3f.
Since your change was applied there have been 14 commits pushed to the master branch:

• 163ab37: 8385628: Typo in jdk.attach comments
• 0a5221d: 8385627: Typo in JMXServiceURL.java: misssing
• 9ed5af9: 8385557: Shenandoah: Runtime calls from C2 stubs need to be relocatable
• ... and 11 more: https://git.openjdk.org/jdk/compare/2b618b4231c14ceee4d0affa39f90cdf6ed40e61...master

Your commit was automatically rebased without conflicts.

[openjdk]

@TheRealMDoerr Pushed as commit f823e3f.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

[dean-long]

Is there a description somewhere on what JDK-6960970 changed that affects the alignment? If a compiled frame starts out as aligned, I don't see how deoptimization could change that alignment. Documenting the root cause somewhere would be helpful for future reference.

[dean-long]

I suspect the real root cause is that this is a heap frame, but frame::patch_pc() is creating a temporary copy w/o preserving if it is a heap frame or not:

jdk/src/hotspot/cpu/ppc/frame_ppc.cpp

Line 322 in 0eeacb5

frame f(this->sp(), pc, this->unextended_sp());

[TheRealMDoerr]

I suspect the real root cause is that this is a heap frame, but frame::patch_pc() is creating a temporary copy w/o preserving if it is a heap frame or not:

jdk/src/hotspot/cpu/ppc/frame_ppc.cpp

Line 322 in 0eeacb5

frame f(this->sp(), pc, this->unextended_sp());

Thanks for looking into it! Right, I have proposed a better fix, also for x86 which uses similar code, but doesn't have the alignment assertion: #31330