RFR: 8251152: ARM32: jtreg c2 Test8202414 test crash

[Filipp Zhinkin]

Hi,

updated webrev:
http://cr.openjdk.java.net/~bulasevich/fzhinkin/8251152/webrev.2/ (I've
updated years in the copyright).

IIRC it's enough to have only one reviewer for such a small change, right?

Thanks,
Filipp.


On Wed, 2 Sep 2020 at 21:53, Igor Ignatyev <igor.ignatyev at oracle.com> wrote:

>
>
> On Sep 2, 2020, at 1:06 AM, Filipp Zhinkin <filipp.zhinkin at gmail.com>
> wrote:
>
> Hi,
>
> updated webrev:
> http://cr.openjdk.java.net/~bulasevich/fzhinkin/8251152/webrev.1/
>
> Tests are throwing SkippedException now, as Igor suggested.
>
> thanks, LGTM.
>
> Seems like I should also update a year in
> JdkInternalMiscUnsafeUnalignedAccess' copyright, but I'm not sure if there
> should be a line designating Oracle as intellectual property owner along
> with SAP. Should I add it too?
>
> IANAL, but unless the file was modified by Oracle, it doesn't have to have
> Oracle copyright notice.
>
> Thanks,
> -- Igor
>
>
> Thanks,
> Filipp.
>
> On Tue, 1 Sep 2020 at 22:48, Filipp Zhinkin <filipp.zhinkin at gmail.com>
> wrote:
>
>> Hi Igor,
>>
>> On Tue, 1 Sep 2020 at 19:46, Igor Ignatyev <igor.ignatyev at oracle.com>
>> wrote:
>>
>>> Hi Filipp,
>>>
>>> 1st of all, welcome back!
>>>
>>
>> thanks!
>>
>>
>>>
>>> it would be better to throw jtreg.SkippedException at L#46 so jtreg will
>>> reported the test as skipped (as opposed to just passed).
>>
>> Thanks, I'll update Test8202414 as well
>> as compiler/unsafe/JdkInternalMiscUnsafeUnalignedAccess (which also skips
>> execution the same way).
>>
>>
>>> alternative, you could use '@requires vm.simpleArch != "arm"' to exclude
>>> the test from arm32 execution.
>>>
>>
>> I was thinking about adding something like vm.unalignedAccess.enabled,
>> but it seems to be too complicated solution for two tests (Test8202414
>> and compiler/unsafe/JdkInternalMiscUnsafeUnalignedAccess).
>> I don't want to use 'simpleArch', because if some new platform missing
>> unaligned access support will be added in the future then someone will have
>> to spend time to find out why a test crashes.
>>
>> Thanks,
>> Filipp.
>>
>>
>>>
>>> Thanks,
>>> -- Igor
>>>
>>>
>>> > On Sep 1, 2020, at 8:29 AM, Filipp Zhinkin <filipp.zhinkin at gmail.com>
>>> wrote:
>>> >
>>> > Hi,
>>> >
>>> > Test8202414 crashes on ARM32 while writing to memory using an unaligned
>>> > address.
>>> > ARM32 supports unaligned memory accesses for some load/store
>>> instructions
>>> > under certain conditions, but LDRD (which is used when we're calling
>>> > Unsafe::putLong) is always causing alignment fault when called with an
>>> > unaligned address [1].
>>> >
>>> > The fix is simply skipping the test execution if a platform does not
>>> > support unaligned memory accesses.
>>> >
>>> > Bug: https://bugs.openjdk.java.net/browse/JDK-8251152
>>> > Webrev:
>>> http://cr.openjdk.java.net/~bulasevich/fzhinkin/8251152/webrev.0/
>>> >
>>> > [1] ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition,
>>> §A3.2.1
>>> > Unaligned data access
>>> https://developer.arm.com/documentation/ddi0406/cd
>>> <https://urldefense.com/v3/__https://developer.arm.com/documentation/ddi0406/cd__;!!GqivPVa7Brio!LmT9wbXnxT5H1XrOZaO8lKj3bT1acuEZPfqS39n-zC99pnrihbCQokSh2J1jqf-MSEE$>
>>> >
>>> > Thanks,
>>> > Filipp.
>>>
>>>
>