/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "instrumentation.h"
#include <sys/uio.h>
#include "atomic_integer.h"
#include "base/unix_file/fd_file.h"
#include "class_linker.h"
#include "debugger.h"
#include "dex_file-inl.h"
#include "mirror/art_method-inl.h"
#include "mirror/class-inl.h"
#include "mirror/dex_cache.h"
#include "mirror/object_array-inl.h"
#include "mirror/object-inl.h"
#include "nth_caller_visitor.h"
#if !defined(ART_USE_PORTABLE_COMPILER)
#include "entrypoints/quick/quick_entrypoints.h"
#endif
#include "object_utils.h"
#include "os.h"
#include "scoped_thread_state_change.h"
#include "thread.h"
#include "thread_list.h"
namespace art {
namespace instrumentation {
static bool InstallStubsClassVisitor(mirror::Class* klass, void* arg)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
Instrumentation* instrumentation = reinterpret_cast<Instrumentation*>(arg);
return instrumentation->InstallStubsForClass(klass);
}
bool Instrumentation::InstallStubsForClass(mirror::Class* klass) {
bool uninstall = !entry_exit_stubs_installed_ && !interpreter_stubs_installed_;
ClassLinker* class_linker = NULL;
if (uninstall) {
class_linker = Runtime::Current()->GetClassLinker();
}
bool is_initialized = klass->IsInitialized();
for (size_t i = 0; i < klass->NumDirectMethods(); i++) {
mirror::ArtMethod* method = klass->GetDirectMethod(i);
if (!method->IsAbstract() && !method->IsProxyMethod()) {
const void* new_code;
if (uninstall) {
if (forced_interpret_only_ && !method->IsNative()) {
new_code = GetCompiledCodeToInterpreterBridge();
} else if (is_initialized || !method->IsStatic() || method->IsConstructor()) {
new_code = class_linker->GetOatCodeFor(method);
} else {
new_code = GetResolutionTrampoline(class_linker);
}
} else { // !uninstall
if (!interpreter_stubs_installed_ || method->IsNative()) {
new_code = GetQuickInstrumentationEntryPoint();
} else {
new_code = GetCompiledCodeToInterpreterBridge();
}
}
method->SetEntryPointFromCompiledCode(new_code);
}
}
for (size_t i = 0; i < klass->NumVirtualMethods(); i++) {
mirror::ArtMethod* method = klass->GetVirtualMethod(i);
if (!method->IsAbstract() && !method->IsProxyMethod()) {
const void* new_code;
if (uninstall) {
if (forced_interpret_only_ && !method->IsNative()) {
new_code = GetCompiledCodeToInterpreterBridge();
} else {
new_code = class_linker->GetOatCodeFor(method);
}
} else { // !uninstall
if (!interpreter_stubs_installed_ || method->IsNative()) {
new_code = GetQuickInstrumentationEntryPoint();
} else {
new_code = GetCompiledCodeToInterpreterBridge();
}
}
method->SetEntryPointFromCompiledCode(new_code);
}
}
return true;
}
// Places the instrumentation exit pc as the return PC for every quick frame. This also allows
// deoptimization of quick frames to interpreter frames.
static void InstrumentationInstallStack(Thread* thread, void* arg)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
struct InstallStackVisitor : public StackVisitor {
InstallStackVisitor(Thread* thread, Context* context, uintptr_t instrumentation_exit_pc)
: StackVisitor(thread, context), instrumentation_stack_(thread->GetInstrumentationStack()),
instrumentation_exit_pc_(instrumentation_exit_pc), last_return_pc_(0) {}
virtual bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
mirror::ArtMethod* m = GetMethod();
if (GetCurrentQuickFrame() == NULL) {
if (kVerboseInstrumentation) {
LOG(INFO) << " Ignoring a shadow frame. Frame " << GetFrameId()
<< " Method=" << PrettyMethod(m);
}
return true; // Ignore shadow frames.
}
if (m == NULL) {
if (kVerboseInstrumentation) {
LOG(INFO) << " Skipping upcall. Frame " << GetFrameId();
}
last_return_pc_ = 0;
return true; // Ignore upcalls.
}
if (m->IsRuntimeMethod()) {
if (kVerboseInstrumentation) {
LOG(INFO) << " Skipping runtime method. Frame " << GetFrameId();
}
last_return_pc_ = GetReturnPc();
return true; // Ignore unresolved methods since they will be instrumented after resolution.
}
if (kVerboseInstrumentation) {
LOG(INFO) << " Installing exit stub in " << DescribeLocation();
}
uintptr_t return_pc = GetReturnPc();
CHECK_NE(return_pc, instrumentation_exit_pc_);
CHECK_NE(return_pc, 0U);
InstrumentationStackFrame instrumentation_frame(GetThisObject(), m, return_pc, GetFrameId(),
false);
if (kVerboseInstrumentation) {
LOG(INFO) << "Pushing frame " << instrumentation_frame.Dump();
}
instrumentation_stack_->push_back(instrumentation_frame);
dex_pcs_.push_back(m->ToDexPc(last_return_pc_));
SetReturnPc(instrumentation_exit_pc_);
last_return_pc_ = return_pc;
return true; // Continue.
}
std::deque<InstrumentationStackFrame>* const instrumentation_stack_;
std::vector<uint32_t> dex_pcs_;
const uintptr_t instrumentation_exit_pc_;
uintptr_t last_return_pc_;
};
if (kVerboseInstrumentation) {
std::string thread_name;
thread->GetThreadName(thread_name);
LOG(INFO) << "Installing exit stubs in " << thread_name;
}
UniquePtr<Context> context(Context::Create());
uintptr_t instrumentation_exit_pc = GetQuickInstrumentationExitPc();
InstallStackVisitor visitor(thread, context.get(), instrumentation_exit_pc);
visitor.WalkStack(true);
// Create method enter events for all methods current on the thread's stack.
Instrumentation* instrumentation = reinterpret_cast<Instrumentation*>(arg);
typedef std::deque<InstrumentationStackFrame>::const_reverse_iterator It;
for (It it = thread->GetInstrumentationStack()->rbegin(),
end = thread->GetInstrumentationStack()->rend(); it != end; ++it) {
mirror::Object* this_object = (*it).this_object_;
mirror::ArtMethod* method = (*it).method_;
uint32_t dex_pc = visitor.dex_pcs_.back();
visitor.dex_pcs_.pop_back();
instrumentation->MethodEnterEvent(thread, this_object, method, dex_pc);
}
thread->VerifyStack();
}
// Removes the instrumentation exit pc as the return PC for every quick frame.
static void InstrumentationRestoreStack(Thread* thread, void* arg)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
struct RestoreStackVisitor : public StackVisitor {
RestoreStackVisitor(Thread* thread, uintptr_t instrumentation_exit_pc,
Instrumentation* instrumentation)
: StackVisitor(thread, NULL), thread_(thread),
instrumentation_exit_pc_(instrumentation_exit_pc),
instrumentation_(instrumentation),
instrumentation_stack_(thread->GetInstrumentationStack()),
frames_removed_(0) {}
virtual bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
if (instrumentation_stack_->size() == 0) {
return false; // Stop.
}
mirror::ArtMethod* m = GetMethod();
if (GetCurrentQuickFrame() == NULL) {
if (kVerboseInstrumentation) {
LOG(INFO) << " Ignoring a shadow frame. Frame " << GetFrameId() << " Method=" << PrettyMethod(m);
}
return true; // Ignore shadow frames.
}
if (m == NULL) {
if (kVerboseInstrumentation) {
LOG(INFO) << " Skipping upcall. Frame " << GetFrameId();
}
return true; // Ignore upcalls.
}
bool removed_stub = false;
// TODO: make this search more efficient?
for (InstrumentationStackFrame instrumentation_frame : *instrumentation_stack_) {
if (instrumentation_frame.frame_id_ == GetFrameId()) {
if (kVerboseInstrumentation) {
LOG(INFO) << " Removing exit stub in " << DescribeLocation();
}
if (instrumentation_frame.interpreter_entry_) {
CHECK(m == Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsAndArgs));
} else {
CHECK(m == instrumentation_frame.method_) << PrettyMethod(m);
}
SetReturnPc(instrumentation_frame.return_pc_);
// Create the method exit events. As the methods didn't really exit the result is 0.
instrumentation_->MethodExitEvent(thread_, instrumentation_frame.this_object_, m,
GetDexPc(), JValue());
frames_removed_++;
removed_stub = true;
break;
}
}
if (!removed_stub) {
if (kVerboseInstrumentation) {
LOG(INFO) << " No exit stub in " << DescribeLocation();
}
}
return true; // Continue.
}
Thread* const thread_;
const uintptr_t instrumentation_exit_pc_;
Instrumentation* const instrumentation_;
std::deque<instrumentation::InstrumentationStackFrame>* const instrumentation_stack_;
size_t frames_removed_;
};
if (kVerboseInstrumentation) {
std::string thread_name;
thread->GetThreadName(thread_name);
LOG(INFO) << "Removing exit stubs in " << thread_name;
}
std::deque<instrumentation::InstrumentationStackFrame>* stack = thread->GetInstrumentationStack();
if (stack->size() > 0) {
Instrumentation* instrumentation = reinterpret_cast<Instrumentation*>(arg);
uintptr_t instrumentation_exit_pc = GetQuickInstrumentationExitPc();
RestoreStackVisitor visitor(thread, instrumentation_exit_pc, instrumentation);
visitor.WalkStack(true);
CHECK_EQ(visitor.frames_removed_, stack->size());
while (stack->size() > 0) {
stack->pop_front();
}
}
}
void Instrumentation::AddListener(InstrumentationListener* listener, uint32_t events) {
Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
bool require_entry_exit_stubs = false;
bool require_interpreter = false;
if ((events & kMethodEntered) != 0) {
method_entry_listeners_.push_back(listener);
require_entry_exit_stubs = true;
have_method_entry_listeners_ = true;
}
if ((events & kMethodExited) != 0) {
method_exit_listeners_.push_back(listener);
require_entry_exit_stubs = true;
have_method_exit_listeners_ = true;
}
if ((events & kMethodUnwind) != 0) {
method_unwind_listeners_.push_back(listener);
have_method_unwind_listeners_ = true;
}
if ((events & kDexPcMoved) != 0) {
dex_pc_listeners_.push_back(listener);
require_interpreter = true;
have_dex_pc_listeners_ = true;
}
if ((events & kExceptionCaught) != 0) {
exception_caught_listeners_.push_back(listener);
have_exception_caught_listeners_ = true;
}
ConfigureStubs(require_entry_exit_stubs, require_interpreter);
}
void Instrumentation::RemoveListener(InstrumentationListener* listener, uint32_t events) {
Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
bool require_entry_exit_stubs = false;
bool require_interpreter = false;
if ((events & kMethodEntered) != 0) {
bool contains = std::find(method_entry_listeners_.begin(), method_entry_listeners_.end(),
listener) != method_entry_listeners_.end();
if (contains) {
method_entry_listeners_.remove(listener);
}
have_method_entry_listeners_ = method_entry_listeners_.size() > 0;
require_entry_exit_stubs |= have_method_entry_listeners_;
}
if ((events & kMethodExited) != 0) {
bool contains = std::find(method_exit_listeners_.begin(), method_exit_listeners_.end(),
listener) != method_exit_listeners_.end();
if (contains) {
method_exit_listeners_.remove(listener);
}
have_method_exit_listeners_ = method_exit_listeners_.size() > 0;
require_entry_exit_stubs |= have_method_exit_listeners_;
}
if ((events & kMethodUnwind) != 0) {
method_unwind_listeners_.remove(listener);
}
if ((events & kDexPcMoved) != 0) {
bool contains = std::find(dex_pc_listeners_.begin(), dex_pc_listeners_.end(),
listener) != dex_pc_listeners_.end();
if (contains) {
dex_pc_listeners_.remove(listener);
}
have_dex_pc_listeners_ = dex_pc_listeners_.size() > 0;
require_interpreter |= have_dex_pc_listeners_;
}
if ((events & kExceptionCaught) != 0) {
exception_caught_listeners_.remove(listener);
have_exception_caught_listeners_ = exception_caught_listeners_.size() > 0;
}
ConfigureStubs(require_entry_exit_stubs, require_interpreter);
}
void Instrumentation::ConfigureStubs(bool require_entry_exit_stubs, bool require_interpreter) {
interpret_only_ = require_interpreter || forced_interpret_only_;
// Compute what level of instrumentation is required and compare to current.
int desired_level, current_level;
if (require_interpreter) {
desired_level = 2;
} else if (require_entry_exit_stubs) {
desired_level = 1;
} else {
desired_level = 0;
}
if (interpreter_stubs_installed_) {
current_level = 2;
} else if (entry_exit_stubs_installed_) {
current_level = 1;
} else {
current_level = 0;
}
if (desired_level == current_level) {
// We're already set.
return;
}
Thread* self = Thread::Current();
Runtime* runtime = Runtime::Current();
Locks::thread_list_lock_->AssertNotHeld(self);
if (desired_level > 0) {
if (require_interpreter) {
interpreter_stubs_installed_ = true;
} else {
CHECK(require_entry_exit_stubs);
entry_exit_stubs_installed_ = true;
}
runtime->GetClassLinker()->VisitClasses(InstallStubsClassVisitor, this);
instrumentation_stubs_installed_ = true;
MutexLock mu(Thread::Current(), *Locks::thread_list_lock_);
runtime->GetThreadList()->ForEach(InstrumentationInstallStack, this);
} else {
interpreter_stubs_installed_ = false;
entry_exit_stubs_installed_ = false;
runtime->GetClassLinker()->VisitClasses(InstallStubsClassVisitor, this);
instrumentation_stubs_installed_ = false;
MutexLock mu(self, *Locks::thread_list_lock_);
Runtime::Current()->GetThreadList()->ForEach(InstrumentationRestoreStack, this);
}
}
void Instrumentation::UpdateMethodsCode(mirror::ArtMethod* method, const void* code) const {
if (LIKELY(!instrumentation_stubs_installed_)) {
method->SetEntryPointFromCompiledCode(code);
} else {
if (!interpreter_stubs_installed_ || method->IsNative()) {
method->SetEntryPointFromCompiledCode(GetQuickInstrumentationEntryPoint());
} else {
method->SetEntryPointFromCompiledCode(GetCompiledCodeToInterpreterBridge());
}
}
}
const void* Instrumentation::GetQuickCodeFor(const mirror::ArtMethod* method) const {
Runtime* runtime = Runtime::Current();
if (LIKELY(!instrumentation_stubs_installed_)) {
const void* code = method->GetEntryPointFromCompiledCode();
DCHECK(code != NULL);
if (LIKELY(code != GetQuickResolutionTrampoline(runtime->GetClassLinker()) &&
code != GetQuickToInterpreterBridge())) {
return code;
}
}
return runtime->GetClassLinker()->GetOatCodeFor(method);
}
void Instrumentation::MethodEnterEventImpl(Thread* thread, mirror::Object* this_object,
const mirror::ArtMethod* method,
uint32_t dex_pc) const {
auto it = method_entry_listeners_.begin();
bool is_end = (it == method_entry_listeners_.end());
// Implemented this way to prevent problems caused by modification of the list while iterating.
while (!is_end) {
InstrumentationListener* cur = *it;
++it;
is_end = (it == method_entry_listeners_.end());
cur->MethodEntered(thread, this_object, method, dex_pc);
}
}
void Instrumentation::MethodExitEventImpl(Thread* thread, mirror::Object* this_object,
const mirror::ArtMethod* method,
uint32_t dex_pc, const JValue& return_value) const {
auto it = method_exit_listeners_.begin();
bool is_end = (it == method_exit_listeners_.end());
// Implemented this way to prevent problems caused by modification of the list while iterating.
while (!is_end) {
InstrumentationListener* cur = *it;
++it;
is_end = (it == method_exit_listeners_.end());
cur->MethodExited(thread, this_object, method, dex_pc, return_value);
}
}
void Instrumentation::MethodUnwindEvent(Thread* thread, mirror::Object* this_object,
const mirror::ArtMethod* method,
uint32_t dex_pc) const {
if (have_method_unwind_listeners_) {
for (InstrumentationListener* listener : method_unwind_listeners_) {
listener->MethodUnwind(thread, method, dex_pc);
}
}
}
void Instrumentation::DexPcMovedEventImpl(Thread* thread, mirror::Object* this_object,
const mirror::ArtMethod* method,
uint32_t dex_pc) const {
// TODO: STL copy-on-write collection? The copy below is due to the debug listener having an
// action where it can remove itself as a listener and break the iterator. The copy only works
// around the problem and in general we may have to move to something like reference counting to
// ensure listeners are deleted correctly.
std::list<InstrumentationListener*> copy(dex_pc_listeners_);
for (InstrumentationListener* listener : copy) {
listener->DexPcMoved(thread, this_object, method, dex_pc);
}
}
void Instrumentation::ExceptionCaughtEvent(Thread* thread, const ThrowLocation& throw_location,
mirror::ArtMethod* catch_method,
uint32_t catch_dex_pc,
mirror::Throwable* exception_object) {
if (have_exception_caught_listeners_) {
DCHECK_EQ(thread->GetException(NULL), exception_object);
thread->ClearException();
for (InstrumentationListener* listener : exception_caught_listeners_) {
listener->ExceptionCaught(thread, throw_location, catch_method, catch_dex_pc, exception_object);
}
thread->SetException(throw_location, exception_object);
}
}
static void CheckStackDepth(Thread* self, const InstrumentationStackFrame& instrumentation_frame,
int delta)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
size_t frame_id = StackVisitor::ComputeNumFrames(self) + delta;
if (frame_id != instrumentation_frame.frame_id_) {
LOG(ERROR) << "Expected frame_id=" << frame_id << " but found "
<< instrumentation_frame.frame_id_;
StackVisitor::DescribeStack(self);
CHECK_EQ(frame_id, instrumentation_frame.frame_id_);
}
}
void Instrumentation::PushInstrumentationStackFrame(Thread* self, mirror::Object* this_object,
mirror::ArtMethod* method,
uintptr_t lr, bool interpreter_entry) {
// We have a callee-save frame meaning this value is guaranteed to never be 0.
size_t frame_id = StackVisitor::ComputeNumFrames(self);
std::deque<instrumentation::InstrumentationStackFrame>* stack = self->GetInstrumentationStack();
if (kVerboseInstrumentation) {
LOG(INFO) << "Entering " << PrettyMethod(method) << " from PC " << reinterpret_cast<void*>(lr);
}
instrumentation::InstrumentationStackFrame instrumentation_frame(this_object, method, lr,
frame_id, interpreter_entry);
stack->push_front(instrumentation_frame);
MethodEnterEvent(self, this_object, method, 0);
}
uint64_t Instrumentation::PopInstrumentationStackFrame(Thread* self, uintptr_t* return_pc,
uint64_t gpr_result, uint64_t fpr_result) {
// Do the pop.
std::deque<instrumentation::InstrumentationStackFrame>* stack = self->GetInstrumentationStack();
CHECK_GT(stack->size(), 0U);
InstrumentationStackFrame instrumentation_frame = stack->front();
stack->pop_front();
// Set return PC and check the sanity of the stack.
*return_pc = instrumentation_frame.return_pc_;
CheckStackDepth(self, instrumentation_frame, 0);
mirror::ArtMethod* method = instrumentation_frame.method_;
char return_shorty = MethodHelper(method).GetShorty()[0];
JValue return_value;
if (return_shorty == 'V') {
return_value.SetJ(0);
} else if (return_shorty == 'F' || return_shorty == 'D') {
return_value.SetJ(fpr_result);
} else {
return_value.SetJ(gpr_result);
}
// TODO: improve the dex pc information here, requires knowledge of current PC as opposed to
// return_pc.
uint32_t dex_pc = DexFile::kDexNoIndex;
mirror::Object* this_object = instrumentation_frame.this_object_;
MethodExitEvent(self, this_object, instrumentation_frame.method_, dex_pc, return_value);
bool deoptimize = false;
if (interpreter_stubs_installed_) {
// Deoptimize unless we're returning to an upcall.
NthCallerVisitor visitor(self, 1, true);
visitor.WalkStack(true);
deoptimize = visitor.caller != NULL;
if (deoptimize && kVerboseInstrumentation) {
LOG(INFO) << "Deoptimizing into " << PrettyMethod(visitor.caller);
}
}
if (deoptimize) {
if (kVerboseInstrumentation) {
LOG(INFO) << "Deoptimizing from " << PrettyMethod(method)
<< " result is " << std::hex << return_value.GetJ();
}
self->SetDeoptimizationReturnValue(return_value);
return static_cast<uint64_t>(GetQuickDeoptimizationEntryPoint()) |
(static_cast<uint64_t>(*return_pc) << 32);
} else {
if (kVerboseInstrumentation) {
LOG(INFO) << "Returning from " << PrettyMethod(method)
<< " to PC " << reinterpret_cast<void*>(*return_pc);
}
return *return_pc;
}
}
void Instrumentation::PopMethodForUnwind(Thread* self, bool is_deoptimization) const {
// Do the pop.
std::deque<instrumentation::InstrumentationStackFrame>* stack = self->GetInstrumentationStack();
CHECK_GT(stack->size(), 0U);
InstrumentationStackFrame instrumentation_frame = stack->front();
// TODO: bring back CheckStackDepth(self, instrumentation_frame, 2);
stack->pop_front();
mirror::ArtMethod* method = instrumentation_frame.method_;
if (is_deoptimization) {
if (kVerboseInstrumentation) {
LOG(INFO) << "Popping for deoptimization " << PrettyMethod(method);
}
} else {
if (kVerboseInstrumentation) {
LOG(INFO) << "Popping for unwind " << PrettyMethod(method);
}
// Notify listeners of method unwind.
// TODO: improve the dex pc information here, requires knowledge of current PC as opposed to
// return_pc.
uint32_t dex_pc = DexFile::kDexNoIndex;
MethodUnwindEvent(self, instrumentation_frame.this_object_, method, dex_pc);
}
}
std::string InstrumentationStackFrame::Dump() const {
std::ostringstream os;
os << "Frame " << frame_id_ << " " << PrettyMethod(method_) << ":"
<< reinterpret_cast<void*>(return_pc_) << " this=" << reinterpret_cast<void*>(this_object_);
return os.str();
}
} // namespace instrumentation
} // namespace art