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

[Richard Reingruber]

On Wed, 16 Dec 2020 09:53:46 GMT, Martin Doerr <mdoerr 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.

Thanks again for the reviews @TheRealMDoerr, @RealLucy!

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