Review Request: JDK-8157464: StackWalker.getCallerClass() should not filter out non-invoker frames

[Daniel Fuchs]

Hi Mandy,

I wonder whether intermediate frames should be skipped always, whether
the method is @CS or not. Indeed StackWalker::getCallerClass() is
intented to be called from methods that are not @CS.

If so the code in stackwalk.cpp could probably be simplified to simply
look at method->is_ignored_by_security_stack_walk() when the
JVM_STACKWALK_GET_CALLER_CLASS is set, and the @CS flag
could be ignored.

(I'm comparing with what I see in jvm.cpp:JVM_GetCallerClass)

what do you think?

best regards,

-- daniel

On 13/07/16 12:01, Mandy Chung wrote:
> Webrev:
>   http://cr.openjdk.java.net/~mchung/jdk9/webrevs/8157464/webrev.00/index.html
>
> StackWalker::getCallerClass() is specified to return the invoker of the MethodHandle and java.lang.reflect.Method for the method calling StackWalker::getCallerClass().
>
> StackWalker::getCallerClass() is not used by any @CallerSensitive method.  Instead one intended usage of StackWalker::getCallerClass() is to be called by library code acting as an agent that calls @CallerSensitive method on behalf of the true caller and typically it will call an appropriate method with the appropriate parameter (e.g. ResourceBundle.getBundle(String, ClassLoader).
>
> MethodHandle for @CS method behaves as if the caller is the lookup class.  The actual caller class may not be the lookup class which is left as implementation details.  This patch adjusts the stack walker to return the same caller as jdk.internal.reflect.Reflection::getCallerClass.
>
> Mandy
>
>
>