[riscv-port-jdk11u:riscv-port] RFR: 8276799: Implementation of JEP 422: Linux/RISC-V Port [v5]

[Xiaolin Zheng]

On Wed, 20 Sep 2023 12:16:09 GMT, Andreas Schwab <duke at openjdk.org> wrote:

>> kuaiwei has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   8247533: SA stack walking sometimes fails with sun.jvm.hotspot.debugger.DebuggerException: get_thread_regs failed for a lwp
>>   
>>   Reviewed-by: sspitsyn, ysuenaga, dtitov
>
> What is fastdebug?

@andreas-schwab Looks like your latest fastdebug build shows some helpful information.
https://build.opensuse.org/package/live_build_log/home:Andreas_Schwab:riscv:java:test/java-11-openjdk/standard/riscv64


...
...
[16101s]  252	Epilog	===  [[]]   [-2147254162]
[16101s] # pop frame 64
[16101s] 	add  sp, sp, #64
[16101s] 	ld  ra, [sp,#-16]
[16101s] 	ld  fp, [sp,#-8]
[16101s] 	# touch polling page
[16101s] 	li  t0, #0x2aaabcde1000
[16101s] 	ld  zr, [t0] n_size (272), current_offset (632), instr_offset (352)
[16101s] Could not load hsdis-riscv64.so; library not loadable; PrintAssembly is disabled
[16101s]  ------------------- 
[16101s] # To suppress the following error report, specify this argument
[16101s] # after -XX: or in .hotspotrc:  SuppressErrorAt=/output.cpp:1416
[16101s] #
[16101s] # A fatal error has been detected by the Java Runtime Environment:
...
...


It looks very similar to [JDK-8283737](https://bugs.openjdk.org/browse/JDK-8283737), which has been pushed to this PR and shares a similar trace of `li` emissions:

MachEpilogNode::emit
    -> reserved_stack_check()
         -> should_not_reach_here()
              -> stop(const char *msg)

In that case, the second `li()` may not generate a fixed-length instruction size, depending on the current PC address within the code buffer that contains instructions emitted from `MacroAssembler::stop`.

I assume this shall fix the issue in your CI with the latest version of this PR. However, your CI still fails - so I was wondering if you have installed the latest version of this PR? Thanks.

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

PR Comment: https://git.openjdk.org/riscv-port-jdk11u/pull/3#issuecomment-1728716579