----- Mail original ----- > De: "David Holmes" <david.hol...@oracle.com> > À: "Remi Forax" <fo...@univ-mlv.fr>, "core-libs-dev" > <core-libs-dev@openjdk.java.net> > Envoyé: Lundi 30 Novembre 2020 08:57:37 > Objet: Re: Why having the wrong InnerClasses attribute is an issue for the VM > ?
> On 30/11/2020 5:08 pm, Remi Forax wrote: >> I've forgotten a cast in an invokedynamic, hence a call to wrongTargetType, >> but in order to create the error message, MethodType.toString(), >> getSimpleName() >> is called and it fails because getDeclaringClass() verifies the InnerClasses >> attribute. >> >> For me InnerClasses was just an attribute for javac not something the VM >> should >> take care of, >> it seems that the VM strongly verifies this attribute and i wonder what is >> the >> reason behind that ? > > From the VM code - InstanceKlass::compute_enclosing_class: > > // Throws an exception if outer klass has not declared k as an inner > klass > // We need evidence that each klass knows about the other, or else > // the system could allow a spoof of an inner class to gain access > rights. > Reflection::check_for_inner_class(outer_klass, this, > *inner_is_member, CHECK_NULL); I don't understand how to spoof the InnerClasses attribute to gain access given that the access rights are not based on the InnerClasses attribute. > > David Rémi > >> regards, >> Rémi >> >> Exception in thread "main" java.lang.IncompatibleClassChangeError: >> fr.umlv.transmogrif.ImplMap and >> fr.umlv.transmogrif.ImplMap$Row/0x0000000801007400 disagree on InnerClasses >> attribute >> at java.base/java.lang.Class.getDeclaringClass0(Native Method) >> at java.base/java.lang.Class.isTopLevelClass(Class.java:1970) >> at java.base/java.lang.Class.getSimpleBinaryName(Class.java:1955) >> at java.base/java.lang.Class.getSimpleName0(Class.java:1835) >> at java.base/java.lang.Class.getSimpleName(Class.java:1826) >> at java.base/java.lang.Class.getSimpleName0(Class.java:1833) >> at java.base/java.lang.Class.getSimpleName(Class.java:1826) >> at >> java.base/java.lang.invoke.MethodType.toString(MethodType.java:895) >> at java.base/java.lang.String.valueOf(String.java:3365) >> at java.base/java.lang.StringBuilder.append(StringBuilder.java:169) >> at >> >> java.base/java.lang.invoke.MethodHandle.standardString(MethodHandle.java:1611) >> at >> java.base/java.lang.invoke.MethodHandle.toString(MethodHandle.java:1608) >> at java.base/java.lang.String.valueOf(String.java:3365) >> at >> java.base/java.lang.invoke.CallSite.wrongTargetType(CallSite.java:203) >> at java.base/java.lang.invoke.CallSite.makeSite(CallSite.java:333) >> at >> >> java.base/java.lang.invoke.MethodHandleNatives.linkCallSiteImpl(MethodHandleNatives.java:280) >> at >> >> java.base/java.lang.invoke.MethodHandleNatives.linkCallSite(MethodHandleNatives.java:270) >> at >> fr.umlv.transmogrif.ImplMap/0x0000000801003c00.<init>(ImplMap.java:21) >> at fr.umlv.transmogrif.Main.main(Main.java:7)
