RFR: 8062672: JVM crashes during GC on various asserts which checks that HeapWord ptr is an oop

[Stefan Johansson]

Thanks for the reviews Jon and Bengt,

Stefan

On 2014-12-11 09:12, Bengt Rutisson wrote:
>
> Hi Stefan,
>
> With the changes you propose based on Jon's review this looks good to me.
>
> Thanks,
> Bengt
>
>
> On 12/8/14 3:23 PM, Stefan Johansson wrote:
>> Thanks for looking at this Jon,
>>
>> On 2014-12-05 23:30, Jon Masamitsu wrote:
>>> Stefan,
>>>
>>> Changes look good.
>>>
>>> Would you like to explicitly check the return from
>>> fgets() against NULL?  Your call.
>>>
>> I see that all other while(fgets...) checks for != NULL so I will add 
>> it.
>>> What do you think of an assert after the call to fgets() to
>>> check the length of the returned string.
>>>
>>> assert(strnlen(line, 1023) < 1023, "buffer line[1024] is too small.");
>>>
>>> Too paranoid?
>> I like adding an assert, but using strnlen feels a little paranoid 
>> since fgets promise to add '\0' at the end even if the line is longer 
>> than the buffer. So I plan to add this assert:
>> assert(strlen(line) < sizeof(line) - 1, "buffer line[1024] is too 
>> small.");
>>
>> Thanks,
>> Stefan
>>>
>>> Reviewed.
>>>
>>> Jon
>>>
>>> On 12/5/2014 2:01 AM, Stefan Johansson wrote:
>>>> Hi,
>>>>
>>>> Please review this fix for the linux-sparc issue described in:
>>>> https://bugs.openjdk.java.net/browse/JDK-8062672
>>>>
>>>> Webrev:
>>>> http://cr.openjdk.java.net/~sjohanss/8062672/hotspot.00/
>>>>
>>>> Summary:
>>>> This fix is based on 7u-dev because the most linux-sparc testing is 
>>>> done for that release and also because it's unclear if we have time 
>>>> to move the fix the normal way through 9 and 8u before going into 
>>>> 7u. But the main reason is that it would be good to get testing of 
>>>> the fix in 7u before porting it to 8u and 9.
>>>>
>>>> The fix it self is fairly simple, after JDK-8029190 was backported 
>>>> the condition for disabling UseMemSetInBOT changed from 
>>>> is_niagara() to has_blk_init(). This worked well for solaris-sparc 
>>>> but on linux-sparc we previously only set the niagara feature bits, 
>>>> so this change adds support for detecting blk_init support on 
>>>> linux-sparc.
>>>>
>>>> Testing:
>>>> Crashes/asserts was reproducible without the fix and after the fix 
>>>> none have been observed. Also verified that UseMemSetInBOT now is 
>>>> set to false as it should be.
>>>>
>>>> Thanks,
>>>> Stefan
>>>
>>
>