RFR(S): 8158260: PPC64: unaligned Unsafe.getInt can lead to the generation of illegal instructions

[Volker Simonis]

I've just pushed the fix to jdk8u-dev:

http://hg.openjdk.java.net/jdk8u/jdk8u-dev/hotspot/rev/6021c95f5944

Regards,
Volker


On Wed, Jun 22, 2016 at 11:38 AM, Volker Simonis
<volker.simonis at gmail.com> wrote:
> Sure. I've just send out the request for approval:
>
> http://mail.openjdk.java.net/pipermail/jdk8u-dev/2016-June/005626.html
>
> Should be there in a few days.
>
> Regards,
> Volker
>
> On Tue, Jun 21, 2016 at 6:34 PM, Tiago Daitx <tiago.daitx at canonical.com> wrote:
>> Hi,
>>
>> I have seen this fix being applied to OpenJDK 9. As Gustavo said, it
>> applies cleanly to jdk8u as well and would be great to have that fix
>> there. Is there any plan to backport it?
>>
>> Regards,
>> Tiago
>>
>>
>> On Thu, Jun 16, 2016 at 12:02 PM, Lindenmaier, Goetz
>> <goetz.lindenmaier at sap.com> wrote:
>>> Hi Volker,
>>>
>>> I've looked at the change, it's fine.  Thanks for fixing this.
>>>
>>> Best regards,
>>>   Goetz.
>>>
>>>> -----Original Message-----
>>>> From: ppc-aix-port-dev [mailto:ppc-aix-port-dev-
>>>> bounces at openjdk.java.net] On Behalf Of Volker Simonis
>>>> Sent: Dienstag, 14. Juni 2016 20:12
>>>> To: hotspot compiler <hotspot-compiler-dev at openjdk.java.net>; ppc-aix-
>>>> port-dev at openjdk.java.net; aarch64-port-dev at openjdk.java.net
>>>> Cc: Hiroshi H Horii <HORII at jp.ibm.com>; Gustavo Romero
>>>> <gromero at linux.vnet.ibm.com>
>>>> Subject: RFR(S): 8158260: PPC64: unaligned Unsafe.getInt can lead to the
>>>> generation of illegal instructions
>>>>
>>>> Hi,
>>>>
>>>> can I please get a review for this small change which fixes a code
>>>> generation problem on ppc64:
>>>>
>>>> http://cr.openjdk.java.net/~simonis/webrevs/2016/8158260/
>>>> https://bugs.openjdk.java.net/browse/JDK-8158260
>>>>
>>>> In the case where we access an unaligned address trough Unsafe, we
>>>> could generate an illegal instruction because we didn't correctly
>>>> specify the memory operand of some match rules. The fix is trivial.
>>>>
>>>> Although this change is ppc64-specific I think I need a sponsor
>>>> because the change contains a new regression test which is supposed to
>>>> run on all platforms.
>>>>
>>>> On platforms where Unsafe.unalignedAccess() will return false (e.g.
>>>> Solaris/SPARC) this test will return immediately (and I've verified
>>>> that it works).
>>>>
>>>> I've also added aarch64 to the list of recipients because on aarch64
>>>> Unsafe.unalignedAccess() is apparently supported and it would be nice
>>>> if somebody could check that the new regression test is indeed working
>>>> there.
>>>>
>>>> @Hiroshi, Gustavo: could you please verify that this change is enough
>>>> to fix the initial problems you've observed when running Cassandra on
>>>> Linux/ppc64? The changes from ppc64.ad should easily apply to the
>>>> 8u-dev repository. Once we've got this into jdk9 I'll trigger a
>>>> downport request to get the fix into jdk8 as well.
>>>>
>>>> Thank you and best regards,
>>>> Volker
>>
>>
>>
>> --
>> Tiago Stürmer Daitx
>> Software Engineer
>> tiago.daitx at canonical.com
>>
>> PGP Key: 4096R/F5B213BE (hkp://keyserver.ubuntu.com)
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