RFR(S) 8226406: JVM fails to detect mismatched or corrupt CDS archive

[Ioi Lam]

Hi Calvin,

These changes look good to me.

Thanks
- Ioi

On 7/3/19 5:59 PM, Calvin Cheung wrote:
> bug: https://bugs.openjdk.java.net/browse/JDK-8226406
>
> webrev: http://cr.openjdk.java.net/~ccheung/8226406/webrev.00/
>
> This bug was found during a bootcycle build when a shared archive 
> built by a 64-bit JDK version is used by a 32-bit JDK version. It is 
> due to some of the important header fields such as the _jvm_ident was 
> not checked prior to accessinng other fields such as the 
> _paths_misc_info_size.
>
> This fix involves checking most the fields in CDSFileMapHeaderBase 
> before accessing other fields.
>
> Testing: tiers 1-3.
>
> thanks,
>
> Calvin
>