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/* Copyright (C) 2017 The Android Open Source Project
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This file implements interfaces from the file jvmti.h. This implementation
* is licensed under the same terms as the file jvmti.h. The
* copyright and license information for the file jvmti.h follows.
*
* Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
#include <sstream>
#include <unistd.h>
#include "ti_search.h"
#include "jni.h"
#include "art_field-inl.h"
#include "art_jvmti.h"
#include "base/enums.h"
#include "base/macros.h"
#include "base/memfd.h"
#include "base/os.h"
#include "base/unix_file/fd_file.h"
#include "class_linker.h"
#include "dex/art_dex_file_loader.h"
#include "dex/dex_file.h"
#include "dex/dex_file_loader.h"
#include "jni/jni_internal.h"
#include "mirror/class-inl.h"
#include "mirror/object.h"
#include "mirror/string.h"
#include "nativehelper/scoped_local_ref.h"
#include "obj_ptr-inl.h"
#include "runtime.h"
#include "runtime_callbacks.h"
#include "scoped_thread_state_change-inl.h"
#include "thread-current-inl.h"
#include "thread_list.h"
#include "ti_logging.h"
#include "ti_phase.h"
#include "well_known_classes.h"
namespace openjdkjvmti {
static std::vector<std::string> gSystemOnloadSegments;
static art::ObjPtr<art::mirror::Object> GetSystemProperties(art::Thread* self,
art::ClassLinker* class_linker)
REQUIRES_SHARED(art::Locks::mutator_lock_) {
art::ObjPtr<art::mirror::Class> system_class =
class_linker->LookupClass(self, "Ljava/lang/System;", nullptr);
DCHECK(system_class != nullptr);
DCHECK(system_class->IsInitialized());
art::ArtField* props_field =
system_class->FindDeclaredStaticField("props", "Ljava/util/Properties;");
DCHECK(props_field != nullptr);
art::ObjPtr<art::mirror::Object> props_obj = props_field->GetObject(system_class);
DCHECK(props_obj != nullptr);
return props_obj;
}
static void Update() REQUIRES_SHARED(art::Locks::mutator_lock_) {
if (gSystemOnloadSegments.empty()) {
return;
}
// In the on-load phase we have to modify java.class.path to influence the system classloader.
// As this is an unmodifiable system property, we have to access the "defaults" field.
art::ClassLinker* class_linker = art::Runtime::Current()->GetClassLinker();
DCHECK(class_linker != nullptr);
art::Thread* self = art::Thread::Current();
// Prepare: collect classes, fields and methods.
art::ObjPtr<art::mirror::Class> properties_class =
class_linker->LookupClass(self, "Ljava/util/Properties;", nullptr);
DCHECK(properties_class != nullptr);
ScopedLocalRef<jobject> defaults_jobj(self->GetJniEnv(), nullptr);
{
art::ObjPtr<art::mirror::Object> props_obj = GetSystemProperties(self, class_linker);
art::ArtField* defaults_field =
properties_class->FindDeclaredInstanceField("defaults", "Ljava/util/Properties;");
DCHECK(defaults_field != nullptr);
art::ObjPtr<art::mirror::Object> defaults_obj = defaults_field->GetObject(props_obj);
DCHECK(defaults_obj != nullptr);
defaults_jobj.reset(self->GetJniEnv()->AddLocalReference<jobject>(defaults_obj));
}
art::ArtMethod* get_property =
properties_class->FindClassMethod(
"getProperty",
"(Ljava/lang/String;)Ljava/lang/String;",
art::kRuntimePointerSize);
DCHECK(get_property != nullptr);
DCHECK(!get_property->IsDirect());
DCHECK(get_property->GetDeclaringClass() == properties_class);
art::ArtMethod* set_property =
properties_class->FindClassMethod(
"setProperty",
"(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Object;",
art::kRuntimePointerSize);
DCHECK(set_property != nullptr);
DCHECK(!set_property->IsDirect());
DCHECK(set_property->GetDeclaringClass() == properties_class);
// This is an allocation. Do this late to avoid the need for handles.
ScopedLocalRef<jobject> cp_jobj(self->GetJniEnv(), nullptr);
{
art::ObjPtr<art::mirror::Object> cp_key =
art::mirror::String::AllocFromModifiedUtf8(self, "java.class.path");
if (cp_key == nullptr) {
self->AssertPendingOOMException();
self->ClearException();
return;
}
cp_jobj.reset(self->GetJniEnv()->AddLocalReference<jobject>(cp_key));
}
// OK, now get the current value.
std::string str_value;
{
ScopedLocalRef<jobject> old_value(self->GetJniEnv(),
self->GetJniEnv()->CallObjectMethod(
defaults_jobj.get(),
art::jni::EncodeArtMethod(get_property),
cp_jobj.get()));
DCHECK(old_value.get() != nullptr);
str_value = self->DecodeJObject(old_value.get())->AsString()->ToModifiedUtf8();
self->GetJniEnv()->DeleteLocalRef(old_value.release());
}
// Update the value by appending the new segments.
for (const std::string& segment : gSystemOnloadSegments) {
if (!str_value.empty()) {
str_value += ":";
}
str_value += segment;
}
gSystemOnloadSegments.clear();
// Create the new value object.
ScopedLocalRef<jobject> new_val_jobj(self->GetJniEnv(), nullptr);
{
art::ObjPtr<art::mirror::Object> new_value =
art::mirror::String::AllocFromModifiedUtf8(self, str_value.c_str());
if (new_value == nullptr) {
self->AssertPendingOOMException();
self->ClearException();
return;
}
new_val_jobj.reset(self->GetJniEnv()->AddLocalReference<jobject>(new_value));
}
// Write to the defaults.
ScopedLocalRef<jobject> res_obj(self->GetJniEnv(),
self->GetJniEnv()->CallObjectMethod(defaults_jobj.get(),
art::jni::EncodeArtMethod(set_property),
cp_jobj.get(),
new_val_jobj.get()));
if (self->IsExceptionPending()) {
self->ClearException();
return;
}
}
struct SearchCallback : public art::RuntimePhaseCallback {
void NextRuntimePhase(RuntimePhase phase) override REQUIRES_SHARED(art::Locks::mutator_lock_) {
if (phase == RuntimePhase::kStart) {
// It's time to update the system properties.
Update();
}
}
};
static SearchCallback gSearchCallback;
void SearchUtil::Register() {
art::Runtime* runtime = art::Runtime::Current();
art::ScopedThreadStateChange stsc(art::Thread::Current(),
art::ThreadState::kWaitingForDebuggerToAttach);
art::ScopedSuspendAll ssa("Add search callback");
runtime->GetRuntimeCallbacks()->AddRuntimePhaseCallback(&gSearchCallback);
}
void SearchUtil::Unregister() {
art::ScopedThreadStateChange stsc(art::Thread::Current(),
art::ThreadState::kWaitingForDebuggerToAttach);
art::ScopedSuspendAll ssa("Remove search callback");
art::Runtime* runtime = art::Runtime::Current();
runtime->GetRuntimeCallbacks()->RemoveRuntimePhaseCallback(&gSearchCallback);
}
jvmtiError SearchUtil::AddToBootstrapClassLoaderSearch(jvmtiEnv* env,
const char* segment) {
art::Runtime* current = art::Runtime::Current();
if (current == nullptr) {
return ERR(WRONG_PHASE);
}
if (current->GetClassLinker() == nullptr) {
return ERR(WRONG_PHASE);
}
if (segment == nullptr) {
return ERR(NULL_POINTER);
}
std::string error_msg;
std::vector<std::unique_ptr<const art::DexFile>> dex_files;
const art::ArtDexFileLoader dex_file_loader;
if (!dex_file_loader.Open(segment,
segment,
/* verify= */ true,
/* verify_checksum= */ true,
&error_msg,
&dex_files)) {
JVMTI_LOG(WARNING, env) << "Could not open " << segment << " for boot classpath extension: "
<< error_msg;
return ERR(ILLEGAL_ARGUMENT);
}
art::ScopedObjectAccess soa(art::Thread::Current());
for (std::unique_ptr<const art::DexFile>& dex_file : dex_files) {
current->GetClassLinker()->AppendToBootClassPath(art::Thread::Current(), *dex_file.release());
}
return ERR(NONE);
}
jvmtiError SearchUtil::AddToDexClassLoaderInMemory(jvmtiEnv* jvmti_env,
jobject classloader,
const char* dex_bytes,
jint dex_bytes_length) {
if (jvmti_env == nullptr) {
return ERR(INVALID_ENVIRONMENT);
} else if (art::Thread::Current() == nullptr) {
return ERR(UNATTACHED_THREAD);
} else if (classloader == nullptr) {
return ERR(NULL_POINTER);
} else if (dex_bytes == nullptr) {
return ERR(NULL_POINTER);
} else if (dex_bytes_length <= 0) {
return ERR(ILLEGAL_ARGUMENT);
}
jvmtiPhase phase = PhaseUtil::GetPhaseUnchecked();
// TODO We really should try to support doing this during the ON_LOAD phase.
if (phase != jvmtiPhase::JVMTI_PHASE_LIVE) {
JVMTI_LOG(INFO, jvmti_env) << "Cannot add buffers to classpath during ON_LOAD phase to "
<< "prevent file-descriptor leaking.";
return ERR(WRONG_PHASE);
}
// We have java APIs for adding files to the classpath, we might as well use them. It simplifies a
// lot of code as well.
// Create a memfd
art::File file(art::memfd_create("JVMTI InMemory Added dex file", 0), /*check-usage*/true);
if (file.Fd() < 0) {
char* reason = strerror(errno);
JVMTI_LOG(ERROR, jvmti_env) << "Unable to create memfd due to " << reason;
return ERR(INTERNAL);
}
// Fill it with the buffer.
if (!file.WriteFully(dex_bytes, dex_bytes_length) || file.Flush() != 0) {
JVMTI_LOG(ERROR, jvmti_env) << "Failed to write to memfd!";
return ERR(INTERNAL);
}
// Get the filename in procfs.
std::ostringstream oss;
oss << "/proc/self/fd/" << file.Fd();
std::string seg(oss.str());
// Use common code.
jvmtiError result = AddToDexClassLoader(jvmti_env, classloader, seg.c_str());
// We have either loaded the dex file and have a new MemMap pointing to the same pages or loading
// has failed and the memory isn't needed anymore. Either way we can close the memfd we created
// and return.
if (file.Close() != 0) {
JVMTI_LOG(WARNING, jvmti_env) << "Failed to close memfd!";
}
return result;
}
jvmtiError SearchUtil::AddToDexClassLoader(jvmtiEnv* jvmti_env,
jobject classloader,
const char* segment) {
if (jvmti_env == nullptr) {
return ERR(INVALID_ENVIRONMENT);
} else if (art::Thread::Current() == nullptr) {
return ERR(UNATTACHED_THREAD);
} else if (classloader == nullptr) {
return ERR(NULL_POINTER);
} else if (segment == nullptr) {
return ERR(NULL_POINTER);
}
jvmtiPhase phase = PhaseUtil::GetPhaseUnchecked();
// TODO We really should try to support doing this during the ON_LOAD phase.
if (phase != jvmtiPhase::JVMTI_PHASE_LIVE) {
JVMTI_LOG(INFO, jvmti_env) << "Cannot add to classpath of arbitrary classloaders during "
<< "ON_LOAD phase.";
return ERR(WRONG_PHASE);
}
// We'll use BaseDexClassLoader.addDexPath, as it takes care of array resizing etc. As a downside,
// exceptions are swallowed.
art::Thread* self = art::Thread::Current();
JNIEnv* env = self->GetJniEnv();
if (!env->IsInstanceOf(classloader, art::WellKnownClasses::dalvik_system_BaseDexClassLoader)) {
JVMTI_LOG(ERROR, jvmti_env) << "Unable to add " << segment << " to non BaseDexClassLoader!";
return ERR(CLASS_LOADER_UNSUPPORTED);
}
jmethodID add_dex_path_id = env->GetMethodID(
art::WellKnownClasses::dalvik_system_BaseDexClassLoader,
"addDexPath",
"(Ljava/lang/String;)V");
if (add_dex_path_id == nullptr) {
return ERR(INTERNAL);
}
ScopedLocalRef<jstring> dex_path(env, env->NewStringUTF(segment));
if (dex_path.get() == nullptr) {
return ERR(INTERNAL);
}
env->CallVoidMethod(classloader, add_dex_path_id, dex_path.get());
if (env->ExceptionCheck()) {
{
art::ScopedObjectAccess soa(self);
JVMTI_LOG(ERROR, jvmti_env) << "Failed to add " << segment << " to classloader. Error was "
<< self->GetException()->Dump();
}
env->ExceptionClear();
return ERR(ILLEGAL_ARGUMENT);
}
return OK;
}
jvmtiError SearchUtil::AddToSystemClassLoaderSearch(jvmtiEnv* jvmti_env, const char* segment) {
if (segment == nullptr) {
return ERR(NULL_POINTER);
}
jvmtiPhase phase = PhaseUtil::GetPhaseUnchecked();
if (phase == jvmtiPhase::JVMTI_PHASE_ONLOAD) {
// We could try and see whether it is a valid path. We could also try to allocate Java
// objects to avoid later OOME.
gSystemOnloadSegments.push_back(segment);
return ERR(NONE);
} else if (phase != jvmtiPhase::JVMTI_PHASE_LIVE) {
return ERR(WRONG_PHASE);
}
jobject loader = art::Runtime::Current()->GetSystemClassLoader();
if (loader == nullptr) {
return ERR(INTERNAL);
}
art::Thread* self = art::Thread::Current();
JNIEnv* env = self->GetJniEnv();
if (!env->IsInstanceOf(loader, art::WellKnownClasses::dalvik_system_BaseDexClassLoader)) {
return ERR(INTERNAL);
}
return AddToDexClassLoader(jvmti_env, loader, segment);
}
} // namespace openjdkjvmti