RFR(XS) 8008750 [partfait] Null pointer deference in hotspot/src/share/vm/oops/instanceKlass.hpp

[Coleen Phillimore]

Hi Morris,

This looks better.  The indentation came out weird in the webrev, so 
please fix it if it's wrong (I don't need to see the indentation changes 
if you have to make them).

thanks,
Coleen

On 03/05/2013 07:46 PM, Morris Meyer wrote:
> Thanks for the review Coleen and Vladimir.  Here's the updated webrev.
>
>         --mm
>
> WEBREV - http://cr.openjdk.java.net/~morris/8008750.02
>
> On 3/5/13 6:16 PM, Vladimir Kozlov wrote:
>> On 3/5/13 2:39 PM, Coleen Phillimore wrote:
>>>
>>> Oh, I see.  Can you still use assert rather then ShouldNotReachHere()?
>>> The former will vanish in product but the latter is added in product.
>>
>> Yes, I think we can remove "else { ShouldNotReachHere();" in header 
>> file instanceKlass.hpp and add assert. Method set_host_klass() has 
>> the assert already, we need to add assert to set_implementor().
>>
>> Also in instanceKlass.cpp, Morris, could you reverse check 
>> InstanceKlass::clean_implementors_list()?
>>
>> Thanks,
>> Vladimir
>>
>>>
>>> Coleen
>>>
>>> On 03/05/2013 05:17 PM, Vladimir Kozlov wrote:
>>>> We want to fix cases where Parfait gives "false" positives. That is
>>>> why we need real != NULL check, assert does not help.
>>>>
>>>> Vladimir
>>>>
>>>> On 3/5/13 1:50 PM, Coleen Phillimore wrote:
>>>>> I can't see the parfait link in the bug.
>>>>>
>>>>> What does this change do but check for null in the cases where host
>>>>> class and adr_implementers can't be null?
>>>>>
>>>>> In instanceKlass.hpp ShouldNotReachHere() is enabled in product so 
>>>>> these
>>>>> should be
>>>>> assert(host != NULL, "not null");
>>>>> *adr = host;
>>>>>
>>>>> I don't understand the motivation for this change and would rather 
>>>>> not
>>>>> enable these ShouldNotReachHere() in product mode, ie use asserts
>>>>> instead.
>>>>>
>>>>> Coleen
>>>>>
>>>>> On 03/05/2013 03:51 PM, Vladimir Kozlov wrote:
>>>>>> Looks good. CC to runtime group.
>>>>>>
>>>>>> Vladimir
>>>>>>
>>>>>> On 3/5/13 12:37 PM, Morris Meyer wrote:
>>>>>>> Folks,
>>>>>>>
>>>>>>> Could I get a review for this parfait issue? This has been through
>>>>>>> JPRT.
>>>>>>>
>>>>>>> Thanks much,
>>>>>>>
>>>>>>>          --mm
>>>>>>>
>>>>>>> WEBREV - http://cr.openjdk.java.net/~morris/8008750.01
>>>>>>> BUG - https://jbs.oracle.com/bugs/browse/JDK-8008750
>>>>>
>>>
>