Howto replicate failure of 8254790?

[Vladimir Kozlov]

Hi Jason,

I added surrounding instructions dump from hs_err file we have so you can reconstruct x86 assembler from it.

If you look on si_addr: 0x00000000e41d2718 which case memory map failure, it looks like R8 =0x00000007e41d2700 is an 
oop: [B with upper 32-bits zeroed. It seems uppers 32-bits of address were cut.

But I don't see it can happens in stringL_indexof_char() sub. You correctly used movptr() and addptr() instructions.

Vladimir K

On 10/15/20 2:10 PM, Tatton, Jason wrote:
> Thanks Vladimir and David, I have access to a new macbook with an Intel i7-9750H (supports AVX2) so I will try on that.
> 
> -----Original Message-----
> From: Vladimir Kozlov <vladimir.kozlov at oracle.com>
> Sent: 15 October 2020 20:25
> To: David Holmes <david.holmes at oracle.com>; Tatton, Jason <jptatton at amazon.com>; hotspot-compiler-dev at openjdk.java.net; core-libs-dev at openjdk.java.net
> Subject: RE: [EXTERNAL] Howto replicate failure of 8254790?
> 
> CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe.
> 
> 
> 
> Note, we have old Mac machines in our testing env:
> cx8, cmov, fxsr, ht, mmx, 3dnowpref, sse, sse2, sse3, ssse3, sse4.1, sse4.2, popcnt, lzcnt, tsc, tscinvbit, avx, avx2, aes, erms, clmul, bmi1, bmi2, rtm, adx, fma, vzeroupper, clflush, clflushopt
> 
> Use -XX:UseAVX=2
> 
> But I was not able reproduce failure on my Skylake Linux machine even with -XX:UseAVX=2. Maybe there are other factors on MacOS.
> 
> Regards,
> Vladimir K
> 
> On 10/14/20 5:48 PM, David Holmes wrote:
>> Hi Jason,
>>
>> On 15/10/2020 10:42 am, Tatton, Jason wrote:
>>> Hi all,
>>>
>>>
>>>
>>> I am trying to replicate the failure of the tier2 test mentioned in
>>> 8254790<https://bugs.openjdk.java.net/browse/JDK-8254790> but I am
>>> only seeing it pass under an x86 linux machine. Are there any specific architectural constraints under which this test should be run in order to make it fail?
>>
>> It failed on a Mac, not Linux.
>>
>> Cheers,
>> David
>>
>>>
>>>
>>> I am running the test via: make test TEST="test/jdk/javax/xml/crypto/dsig/GenerationTests.java"
>>>
>>>
>>>
>>> Note that I am running the test against master without the commit:
>>> "8254792: Disable intrinsic StringLatin1.indexOf until 8254790 is fixed" which disables the intrinsic that is causing the test to fail.
>>>
>>>
>>>
>>> Thanks
>>> --
>>> Jason
>>>