RFR: 8296469: Instrument VMError::report with reentrant iteration step for register and stack printing [v9]

[Erik Österlund]

On Mon, 20 Feb 2023 07:15:23 GMT, Axel Boldt-Christmas <aboldtch at openjdk.org> wrote:

>> Add reentrant step logic to VMError::report with an inner loop which enable the logic to recover at every step of the iteration.
>> 
>> Before this change, if printing one register/stack position crashes then no more registers/stack positions will be printed.
>> 
>> After this change even if the VM is unstable and some registers print_location crashes the hs_err printing will recover and keep attempting to print the rest of the registers or stack values.
>> 
>> Enables the following
>> ```C++
>> REENTRANT_STEP_IF("printing register info", _verbose && _context && _thread && Universe::is_fully_initialized())
>>   os::print_register_info_header(st, _context);
>> 
>>   REENTRANT_LOOP_START(os::print_nth_register_info_max_index())
>>     // decode register contents if possible
>>     ResourceMark rm(_thread);
>>     os::print_nth_register_info(st, REENTRANT_ITERATION_STEP, _context);
>>   REENTRANT_LOOP_END
>> 
>>   st->cr();
>> 
>> 
>> Testing: tier 1 and compiled Linux-x64/aarch64, MacOS-x64/aarch64, Windows x64 and cross-compiled Linux-x86/riscv/arm/ppc/s390x (GHA and some local)
>
> Axel Boldt-Christmas has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 15 commits:
> 
>  - Merge remote-tracking branch 'upstream_jdk/master' into vmerror_report_register_stack_reentrant
>  - Add test
>  - Fix and strengthen print_stack_location
>  - Missed variable rename
>  - Copyright
>  - Rework logic and use continuation state for reattempts
>  - Merge remote-tracking branch 'upstream_jdk/master' into vmerror_report_register_stack_reentrant
>  - Restructure os::print_register_info interface
>  - Code syle and line length
>  - Merge Fix
>  - ... and 5 more: https://git.openjdk.org/jdk/compare/2009dc2b...2e12b4a5

Just a naming nit, otherwise it looks good.

src/hotspot/share/utilities/vmError.cpp line 175:

> 173: static bool check_stack_headroom(Thread* thread,
> 174:                                  size_t headroom) {
> 175:   static const address stack_top    = thread != nullptr

We typically call "stack_top "stack_base", and "stack_bottom" we call "stack_end".

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

Marked as reviewed by eosterlund (Reviewer).

PR: https://git.openjdk.org/jdk/pull/11017