RFR: 8195690: JNI GetObjectRefType doesn't handle NULL

[David Holmes]

Hi Kim,

As a general rule JNI does not do argument checking. You pass crud then 
you may crash:

"The programmer must not pass illegal pointers or arguments of the wrong 
type to JNI functions. Doing so could result in arbitrary consequences, 
including a corrupted system state or VM crash."

https://docs.oracle.com/javase/9/docs/specs/jni/design.html#reporting-programming-errors

David
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On 23/01/2018 8:24 AM, Kim Barrett wrote:
> Please review this fix of GetObjectRefType when applied to a NULL
> handle argument.  It should return JNIInvalidRefType, but was instead
> asserting in debug builds, and maybe worse things in release builds.
> 
> In addition to making GetObjectRefType handle NULL properly, various
> functions in JNIHandles and OopStorage now have non-NULL handle argument
> preconditions and corresponding assertions.
> 
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8195690
> 
> Webrev:
> http://cr.openjdk.java.net/~kbarrett/8195690/open.00/
> 
> Testing:
> Mach5 {hs,jdk}-tier{1,2,3}
> Locally ran JCK vm/jni tests
> Locally ran tonga vm.runtime tests for jni tests
>