RFR 8191278: MappedByteBuffer bulk access memory failures are not handled gracefully

[Jamsheed]

Hi Tobias,

Please find the revised webrev.

http://cr.openjdk.java.net/~jcm/8191278/webrev.02/

1) checks were made in StubRoutines unaligned arraycopy code range.

2) tried to implement fastexit for x64(mac,linux,windows,solaris). 
others continue with old implementation.

3) implementation like arm has auto increment mode for from and to 
addresses,  even aligning is done this way. this may make to proceed 
with unaligned addresses.

Best regards,

Jamsheed


On 15/03/19 1:14 PM, Tobias Hartmann wrote:
> Hi Jamsheed,
>
> okay, that looks reasonable to me!
>
> Best regards,
> Tobias
>
> On 15.03.19 01:07, Jamsheed wrote:
>> Hi Tobias,
>>
>> as a fix, for handling  the bugs in hand written assembly stubs, i will put checks like.[1]  instead
>> of StubRoutines::contains(pc).
>>
>> Best regards,
>>
>> Jamsheed
>>
>> [1]
>>
>> bool StubRoutines::is_unsafe_copy(address pc) {
>>      if ((pc > StubRoutines::_jbyte_disjoint_arraycopy && pc <
>> StubRoutines::_arrayof_jbyte_disjoint_arraycopy) ||
>>          (pc > StubRoutines::_jshort_disjoint_arraycopy && pc <
>> StubRoutines::_arrayof_jshort_disjoint_arraycopy) ||
>>          (pc > StubRoutines::_jint_disjoint_arraycopy && pc <
>> StubRoutines::_arrayof_oop_disjoint_arraycopy)) {
>>        return true;
>>      }
>>      return false;
>>    }
>>
>> PS: these code ranges are shared by others too.
>>
>> On 14/03/19 8:46 PM, Jamsheed wrote:
>>> Hi Tobias,
>>>
>>> On 14/03/19 1:58 PM, Tobias Hartmann wrote:
>>>> Hi Jamsheed,
>>>>
>>>> On 14.03.19 02:29, Jamsheed wrote:
>>>>> i will try to limit my checks to array copy stubs. will make changes and send it for review.
>>>> Okay, if there's a simple way to do that. Otherwise, I'm fine with the current version of the fix.
>>> either i should have separate code generated for unsafe copy. or setting/resetting
>>> doing_unsafe_access before after unsafe_copy should do.
>>>
>>> Best regards,
>>>
>>> Jamsheed
>>>> Best regards,
>>>> Tobias