JVMCI may use an incorrect classloader to resolve a callee class

[Tianxiao Gu]

Hi All,

JVMCI may use a wrong classloader to resolve a callee class when the caller
frame (obtained by frame caller_frame =
thread->last_frame().sender(&cbl_map);) is a compiled inlined method (see
CompilerRuntime::resolve_klass_helper at
http://hg.openjdk.java.net/jdk/jdk/file/1afe0cb93482/src/hotspot/share/jvmci/compilerRuntime.cpp#l60
).

In an inlined method, the actual, direct caller of an unresolved callee may
not be the root of the inline tree. The actual caller and the root of the
inline tree may even have different classloaders. This should be a bug and
can be reproduced with the attached test case in JDK 11. A patch would use
vframeStream to walk the stack.

The test case is based on AOT and uses custom classloaders. In JDK 11, we
are still able to use AOT with custom classloaders though it is not
type-safe. (See bug report https://bugs.openjdk.java.net/browse/JDK-8206963).
Custom classloaders have been disabled in AOT in
http://hg.openjdk.java.net/jdk/jdk/rev/ccfa71bacd6f. That means this bug
will not be able to be reproduced in the latest JDK with the attached test
case.

Environment:

$ uname -a

Darwin US-204496-MP.local 18.6.0 Darwin Kernel Version 18.6.0: Thu Apr 25
23:16:27 PDT 2019; root:xnu-4903.261.4~2/RELEASE_X86_64 x86_64

$ java -version

java version "11.0.2" 2019-01-15 LTS

Java(TM) SE Runtime Environment 18.9 (build 11.0.2+9-LTS)

Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.2+9-LTS, mixed mode)

$ jaotc --version

jaotc 11.0.2+9-LTS



Reproducing Steps:
1. Unzip the attached test case and run script run.sh.
2. In AOT mode, we will see a message "Should not load me!", which
indicates that a wrong classloader is used.
3. In interpreter mode, we will not see the message.

Best regards,
Tianxiao
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