Need reviewers for changes in JVM initialization code (added check for -XX:StackShadowPages option)

[Paul Hohensee]

  Leave them as intx, imo.  Their high bound value isn't anywhere near 
maxint,
and if you change them to uintx you'll have to cast them to intx for the
calls to verify_min_value.  Plus there's some places where their values are
assigned to ints that would have to be changed.

Also, pls use INTX_FORMAT instead of UINTX_FORMAT in verify_min_value.

Paul

On 8/17/10 3:50 PM, Tom Rodriguez wrote:
> On Aug 6, 2010, at 7:05 AM, Pavel Tisnovsky wrote:
>
>> Tom Rodriguez wrote:
>>> I think you could put this check into arguments.cpp since I all platforms would require a positive number for the StackShadowPages.  The same should be true of StackRedPages and StackYellowPages.  Actually they all should be required to greater than 0 I think.  Other than that I don't see other obvious constraints on the values.  That bug report doesn't really show other problematic values, though I'm not sure I follow the point of the guarantee that's failing either.  What does the min stack size have to do with the number of guard pages?  I would expect it to be checking against ThreadStackSize and returning an error if it was too small like the other places that check against TheadStackSize.
>>>
>>> tom
>> Hi Tom,
>>
>> I've added check for all Stack*Pages parameters to arguments.cpp. Can
>> you please review the changes?
>>
>> http://cr.openjdk.java.net/~ptisnovs/StackXXXPagesCheck/
>>
>> Is there any reason why Stack*Pages parameters are of type int and not
>> unsigned int? I'm able to change its types (these variables are
>> generated by macro which accepts type as one of its parameter) but I'm
>> not sure if it would be correct in all cases.
> Would someone from runtime want to comment on this?  It seems ok to me.  Changing to uintx would also be ok but it might require other uses to be converted to unsigned as well.  I'd probably just leave it alone myself.
>
> tom
>
>
>> Cheers
>> Pavel
>>
>>> On Jul 27, 2010, at 8:15 AM, Pavel Tisnovsky wrote:
>>>
>>>> Hi all,
>>>>
>>>> can anybody please review two quite simple changes in JVM initialization code? Webrev is available at:
>>>> http://cr.openjdk.java.net/~ptisnovs/StackShadowPagesCheck/
>>>>
>>>> When -XX:StackShadowPages is set to negative integer or zero value, JVM segfaulted on Linux and, according to http://bugs.sun.com/view_bug.do?bug_id=6885308, hangs up on Solaris (although I only check this issue on Linux)
>>>>
>>>> I also would like to add more check for -XX:StackRedPages, -XX:StackShadowPages and -XX:StackYellowPages options to avoid issue described in the bug report mentioned above (http://bugs.sun.com/view_bug.do?bug_id=6885308) but I'm unable to find relevant information about proper conditions (it may depends on page sizes, VM stack size etc.). Any ideas?
>>>>
>>>> Cheers
>>>> Pavel Tisnovsky
>>>>