[jdk16] RFR: 8256843: [PPC64] test RedefineClasses.java fails with assert: registers not saved on stack

[Martin Doerr]

On Tue, 15 Dec 2020 15:34:33 GMT, Richard Reingruber <rrich at openjdk.org> wrote:

> // Continuation of https://github.com/openjdk/jdk/pull/1724
> // I'm taking over from @TheRealMDoerr who's busy with 11u downports
> 
> Please help review this small PPC64 fix.
> It replaces the call os::current_stack_pointer() in os::current_frame()
> with __builtin_frame_address(0) which is available also with xlC used by the AIX
> build. With this os::current_frame() is agnostic to C++ compiler inlining.
> 
> Furthermore the fix changes os::current_frame() to return the correct
> frame. Without the fix the returned frame is one frame to high which triggered
> the assertion in trace_method_handle_stub().
> This change uncovers an issue with NativeCallStack::NativeCallStack(int toSkip, bool fillStack)
> on PPC64. There the call os::get_native_stack() is not compiled
> to a tail call therefore the frame of the NativeCallStack constructor needs to
> be skipped on PPC64 too as on other platforms.
> 
> Without this
> 
> make run-test TEST=test/hotspot/jtreg/runtime/NMT/CheckForProperDetailStackTrace.java
> 
> fails.
> 
> Furthermore the inline assembler from os::current_stack_pointer() is
> removed. Instead __builtin_frame_address(0) is used again.
> 
> The fix passed our CI testing: JCK and JTREG, also in Xcomp mode, SPECjvm2008, SPECjbb2015, Renaissance Suite,
> SAP specific tests with fastdebug and release builds on all platforms

Thank you for fixing it in jdk16 as discussed in the jdk PR!
Note that PR and JBS title must match, otherwise integration is blocked.

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Marked as reviewed by mdoerr (Reviewer).

PR: https://git.openjdk.java.net/jdk16/pull/24