Bug ID: JDK-8167372 Add code to check for getting oops while thread is in native

Type: Enhancement
Component: hotspot
Sub-Component: runtime
Affected Version: 9

Priority: P3
Status: Resolved
Resolution: Fixed

Submitted: 2016-10-07
Updated: 2018-03-27
Resolved: 2017-12-15

JDK 11
11 b01Fixed

Some recent errors in the code have gotten oops, while the thread_in_native which is essentially a naked oop.  Add a check to JNIHandles::make_global/local to make sure thread_in_vm.   See linked bug for details.

I've just noticed that this broke SPARC on old machines (see JDK-8200290).

27-03-2018

Potential fix for this issue once blocking bug JDK-8191227is fixed: diff --git a/src/hotspot/share/runtime/jniHandles.cpp b/src/hotspot/share/runtime/jniHandles.cpp --- a/src/hotspot/share/runtime/jniHandles.cpp +++ b/src/hotspot/share/runtime/jniHandles.cpp @@ -47,6 +47,7 @@ } else { Thread* thread = Thread::current(); assert(Universe::heap()->is_in_reserved(obj), "sanity check"); + assert(!current_thread_in_native(), "must not be in native"); return thread->active_handles()->allocate_handle(obj); } } @@ -59,6 +60,8 @@ return NULL; // ignore null handles } else { assert(Universe::heap()->is_in_reserved(obj), "sanity check"); + assert(thread->is_Java_thread(), "not a Java thread"); + assert(!current_thread_in_native(), "must not be in native"); return thread->active_handles()->allocate_handle(obj); } } @@ -70,6 +73,7 @@ } else { JavaThread* thread = JavaThread::thread_from_jni_environment(env); assert(Universe::heap()->is_in_reserved(obj), "sanity check"); + assert(!current_thread_in_native(), "must not be in native"); return thread->active_handles()->allocate_handle(obj); } } @@ -77,6 +81,7 @@ jobject JNIHandles::make_global(Handle obj) { assert(!Universe::heap()->is_gc_active(), "can't extend the root set during GC"); + assert(!current_thread_in_native(), "must not be in native"); jobject res = NULL; if (!obj.is_null()) { // ignore null handles @@ -93,6 +98,7 @@ jobject JNIHandles::make_weak_global(Handle obj) { assert(!Universe::heap()->is_gc_active(), "can't extend the root set during GC"); + assert(!current_thread_in_native(), "must not be in native"); jobject res = NULL; if (!obj.is_null()) { // ignore null handles @@ -265,6 +271,13 @@ weak_oops_do(&verify_handle); } +// This method is implemented here to avoid circular includes between +// jniHandles.hpp and thread.hpp. +bool JNIHandles::current_thread_in_native() { + Thread* thread = Thread::current(); + return (thread->is_Java_thread() && + JavaThread::current()->thread_state() == _thread_in_native); +} void jni_handles_init() { diff --git a/src/hotspot/share/runtime/jniHandles.hpp b/src/hotspot/share/runtime/jniHandles.hpp --- a/src/hotspot/share/runtime/jniHandles.hpp +++ b/src/hotspot/share/runtime/jniHandles.hpp @@ -48,6 +48,10 @@ template<bool external_guard> inline static oop resolve_impl(jobject handle); template<bool external_guard> static oop resolve_jweak(jweak handle); + // This method is not inlined in order to avoid circular includes between + // this header file and thread.hpp. + static bool current_thread_in_native(); + public: // Low tag bit in jobject used to distinguish a jweak. jweak is // type equivalent to jobject, but there are places where we need to @@ -231,6 +235,7 @@ template<bool external_guard> inline oop JNIHandles::resolve_impl(jobject handle) { assert(handle != NULL, "precondition"); + assert(!current_thread_in_native(), "must not be in native"); oop result; if (is_jweak(handle)) { // Unlikely result = resolve_jweak<external_guard>(handle);

28-11-2017

Proposed fix: diff --git a/src/share/vm/runtime/jniHandles.cpp b/src/share/vm/runtime/jniHandles.cpp --- a/src/share/vm/runtime/jniHandles.cpp +++ b/src/share/vm/runtime/jniHandles.cpp @@ -46,6 +46,7 @@ } else { Thread* thread = Thread::current(); assert(Universe::heap()->is_in_reserved(obj), "sanity check"); + assert(JavaThread::current()->thread_state() != _thread_in_native, "must not be in native"); return thread->active_handles()->allocate_handle(obj); } } @@ -58,6 +59,8 @@ return NULL; // ignore null handles } else { assert(Universe::heap()->is_in_reserved(obj), "sanity check"); + assert(thread->is_Java_thread(), "not a Java thread"); + assert(((JavaThread *)thread)->thread_state() != _thread_in_native, "must not be in native"); return thread->active_handles()->allocate_handle(obj); } } @@ -69,6 +72,7 @@ } else { JavaThread* thread = JavaThread::thread_from_jni_environment(env); assert(Universe::heap()->is_in_reserved(obj), "sanity check"); + assert(thread->thread_state() != _thread_in_native, "must not be in native"); return thread->active_handles()->allocate_handle(obj); } } @@ -76,6 +80,7 @@ jobject JNIHandles::make_global(Handle obj) { assert(!Universe::heap()->is_gc_active(), "can't extend the root set during GC"); + assert(JavaThread::current()->thread_state() != _thread_in_native, "must not be in native"); jobject res = NULL; if (!obj.is_null()) { // ignore null handles @@ -92,6 +97,7 @@ jobject JNIHandles::make_weak_global(Handle obj) { assert(!Universe::heap()->is_gc_active(), "can't extend the root set during GC"); + assert(JavaThread::current()->thread_state() != _thread_in_native, "must not be in native"); jobject res = NULL; if (!obj.is_null()) { // ignore null handles

01-06-2017

Blocks :	JDK-8191227 - Unsafe handle resolution in ConstantOopWriteValue::write_on() / print_on() and LIR_Assembler::jobject2reg()
Relates :	JDK-8193699 - AArch64: Fails to build after 8167372
Relates :	JDK-8200290 - Scratch buffer creation fails with "assert(!current_thread_in_native()) failed: must not be in native" on SPARC
Relates :	JDK-8162766 - Unsafe_DefineClass0 accesses raw oops while in _thread_in_native