blob: fd57b4ae83c122827fc9499a13193c7dac946d0b [file] [log] [blame]
/*
* Copyright (C) 2014 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 "quick_exception_handler.h"
#include <ios>
#include <queue>
#include <sstream>
#include "arch/context.h"
#include "art_method-inl.h"
#include "base/array_ref.h"
#include "base/enums.h"
#include "base/globals.h"
#include "base/logging.h" // For VLOG_IS_ON.
#include "base/systrace.h"
#include "dex/dex_file_types.h"
#include "dex/dex_instruction.h"
#include "entrypoints/entrypoint_utils.h"
#include "entrypoints/quick/quick_entrypoints_enum.h"
#include "entrypoints/runtime_asm_entrypoints.h"
#include "handle_scope-inl.h"
#include "interpreter/shadow_frame-inl.h"
#include "jit/jit.h"
#include "jit/jit_code_cache.h"
#include "mirror/class-inl.h"
#include "mirror/class_loader.h"
#include "mirror/throwable.h"
#include "nterp_helpers.h"
#include "oat_quick_method_header.h"
#include "stack.h"
#include "stack_map.h"
namespace art {
static constexpr bool kDebugExceptionDelivery = false;
static constexpr size_t kInvalidFrameDepth = 0xffffffff;
QuickExceptionHandler::QuickExceptionHandler(Thread* self, bool is_deoptimization)
: self_(self),
context_(self->GetLongJumpContext()),
is_deoptimization_(is_deoptimization),
handler_quick_frame_(nullptr),
handler_quick_frame_pc_(0),
handler_method_header_(nullptr),
handler_quick_arg0_(0),
clear_exception_(false),
handler_frame_depth_(kInvalidFrameDepth),
full_fragment_done_(false) {}
// Finds catch handler.
class CatchBlockStackVisitor final : public StackVisitor {
public:
CatchBlockStackVisitor(Thread* self,
Context* context,
Handle<mirror::Throwable>* exception,
QuickExceptionHandler* exception_handler,
uint32_t skip_frames,
bool skip_top_unwind_callback)
REQUIRES_SHARED(Locks::mutator_lock_)
: StackVisitor(self, context, StackVisitor::StackWalkKind::kIncludeInlinedFrames),
exception_(exception),
exception_handler_(exception_handler),
skip_frames_(skip_frames),
skip_unwind_callback_(skip_top_unwind_callback) {
DCHECK_IMPLIES(skip_unwind_callback_, skip_frames_ == 0);
}
bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod* method = GetMethod();
exception_handler_->SetHandlerFrameDepth(GetFrameDepth());
if (method == nullptr) {
DCHECK_EQ(skip_frames_, 0u)
<< "We tried to skip an upcall! We should have returned to the upcall to finish delivery";
// This is the upcall, we remember the frame and last pc so that we may long jump to them.
exception_handler_->SetHandlerQuickFramePc(GetCurrentQuickFramePc());
exception_handler_->SetHandlerQuickFrame(GetCurrentQuickFrame());
return false; // End stack walk.
}
if (skip_frames_ != 0) {
skip_frames_--;
return true;
}
if (method->IsRuntimeMethod()) {
// Ignore callee save method.
DCHECK(method->IsCalleeSaveMethod());
return true;
}
bool continue_stack_walk = HandleTryItems(method);
// Collect methods for which MethodUnwind callback needs to be invoked. MethodUnwind callback
// can potentially throw, so we want to call these after we find the catch block.
// We stop the stack walk when we find the catch block. If we are ending the stack walk we don't
// have to unwind this method so don't record it.
if (continue_stack_walk && !skip_unwind_callback_) {
// Skip unwind callback is only used when method exit callback has thrown an exception. In
// that case, we should have runtime method (artMethodExitHook) on top of stack and the
// second should be the method for which method exit was called.
DCHECK_IMPLIES(skip_unwind_callback_, GetFrameDepth() == 2);
unwound_methods_.push(method);
}
skip_unwind_callback_ = false;
return continue_stack_walk;
}
std::queue<ArtMethod*>& GetUnwoundMethods() {
return unwound_methods_;
}
private:
bool HandleTryItems(ArtMethod* method)
REQUIRES_SHARED(Locks::mutator_lock_) {
uint32_t dex_pc = dex::kDexNoIndex;
if (!method->IsNative()) {
dex_pc = GetDexPc();
}
if (dex_pc != dex::kDexNoIndex) {
bool clear_exception = false;
StackHandleScope<1> hs(GetThread());
Handle<mirror::Class> to_find(hs.NewHandle((*exception_)->GetClass()));
uint32_t found_dex_pc = method->FindCatchBlock(to_find, dex_pc, &clear_exception);
exception_handler_->SetClearException(clear_exception);
if (found_dex_pc != dex::kDexNoIndex) {
exception_handler_->SetHandlerDexPcList(ComputeDexPcList(found_dex_pc));
uint32_t stack_map_row = -1;
exception_handler_->SetHandlerQuickFramePc(
GetCurrentOatQuickMethodHeader()->ToNativeQuickPcForCatchHandlers(
method, exception_handler_->GetHandlerDexPcList(), &stack_map_row));
exception_handler_->SetCatchStackMapRow(stack_map_row);
exception_handler_->SetHandlerQuickFrame(GetCurrentQuickFrame());
exception_handler_->SetHandlerMethodHeader(GetCurrentOatQuickMethodHeader());
return false; // End stack walk.
} else if (UNLIKELY(GetThread()->HasDebuggerShadowFrames())) {
// We are going to unwind this frame. Did we prepare a shadow frame for debugging?
size_t frame_id = GetFrameId();
ShadowFrame* frame = GetThread()->FindDebuggerShadowFrame(frame_id);
if (frame != nullptr) {
// We will not execute this shadow frame so we can safely deallocate it.
GetThread()->RemoveDebuggerShadowFrameMapping(frame_id);
ShadowFrame::DeleteDeoptimizedFrame(frame);
}
}
}
return true; // Continue stack walk.
}
// The exception we're looking for the catch block of.
Handle<mirror::Throwable>* exception_;
// The quick exception handler we're visiting for.
QuickExceptionHandler* const exception_handler_;
// The number of frames to skip searching for catches in.
uint32_t skip_frames_;
// The list of methods we would skip to reach the catch block. We record these to call
// MethodUnwind callbacks.
std::queue<ArtMethod*> unwound_methods_;
// Specifies if the unwind callback should be ignored for method at the top of the stack.
bool skip_unwind_callback_;
DISALLOW_COPY_AND_ASSIGN(CatchBlockStackVisitor);
};
// Finds the appropriate exception catch after calling all method exit instrumentation functions.
// Note that this might change the exception being thrown. If is_method_exit_exception is true
// skip the method unwind call for the method on top of the stack as the exception was thrown by
// method exit callback.
void QuickExceptionHandler::FindCatch(ObjPtr<mirror::Throwable> exception,
bool is_method_exit_exception) {
DCHECK(!is_deoptimization_);
instrumentation::Instrumentation* instr = Runtime::Current()->GetInstrumentation();
// The number of total frames we have so far popped.
uint32_t already_popped = 0;
bool popped_to_top = true;
StackHandleScope<1> hs(self_);
MutableHandle<mirror::Throwable> exception_ref(hs.NewHandle(exception));
bool skip_top_unwind_callback = is_method_exit_exception;
// Sending the instrumentation events (done by the InstrumentationStackPopper) can cause new
// exceptions to be thrown which will override the current exception. Therefore we need to perform
// the search for a catch in a loop until we have successfully popped all the way to a catch or
// the top of the stack.
do {
if (kDebugExceptionDelivery) {
ObjPtr<mirror::String> msg = exception_ref->GetDetailMessage();
std::string str_msg(msg != nullptr ? msg->ToModifiedUtf8() : "");
self_->DumpStack(LOG_STREAM(INFO) << "Delivering exception: " << exception_ref->PrettyTypeOf()
<< ": " << str_msg << "\n");
}
// Walk the stack to find catch handler.
CatchBlockStackVisitor visitor(self_,
context_,
&exception_ref,
this,
/*skip_frames=*/already_popped,
skip_top_unwind_callback);
visitor.WalkStack(true);
skip_top_unwind_callback = false;
uint32_t new_pop_count = handler_frame_depth_;
DCHECK_GE(new_pop_count, already_popped);
already_popped = new_pop_count;
if (kDebugExceptionDelivery) {
if (*handler_quick_frame_ == nullptr) {
LOG(INFO) << "Handler is upcall";
}
if (GetHandlerMethod() != nullptr) {
const DexFile* dex_file = GetHandlerMethod()->GetDexFile();
DCHECK(handler_dex_pc_list_.has_value());
DCHECK_GE(handler_dex_pc_list_->size(), 1u);
int line_number = annotations::GetLineNumFromPC(
dex_file, GetHandlerMethod(), handler_dex_pc_list_->front());
// We may have an inlined method. If so, we can add some extra logging.
std::stringstream ss;
ArtMethod* maybe_inlined_method = visitor.GetMethod();
if (maybe_inlined_method != GetHandlerMethod()) {
const DexFile* inlined_dex_file = maybe_inlined_method->GetDexFile();
DCHECK_GE(handler_dex_pc_list_->size(), 2u);
int inlined_line_number = annotations::GetLineNumFromPC(
inlined_dex_file, maybe_inlined_method, handler_dex_pc_list_->back());
ss << " which ends up calling inlined method " << maybe_inlined_method->PrettyMethod()
<< " (line: " << inlined_line_number << ")";
}
LOG(INFO) << "Handler: " << GetHandlerMethod()->PrettyMethod() << " (line: "
<< line_number << ")" << ss.str();
}
}
// Exception was cleared as part of delivery.
DCHECK(!self_->IsExceptionPending());
// If the handler is in optimized code, we need to set the catch environment.
if (*handler_quick_frame_ != nullptr &&
handler_method_header_ != nullptr &&
handler_method_header_->IsOptimized()) {
SetCatchEnvironmentForOptimizedHandler(&visitor);
}
popped_to_top = instr->ProcessMethodUnwindCallbacks(self_,
visitor.GetUnwoundMethods(),
exception_ref);
} while (!popped_to_top);
if (!clear_exception_) {
// Put exception back in root set with clear throw location.
self_->SetException(exception_ref.Get());
}
}
static VRegKind ToVRegKind(DexRegisterLocation::Kind kind) {
// Slightly hacky since we cannot map DexRegisterLocationKind and VRegKind
// one to one. However, StackVisitor::GetVRegFromOptimizedCode only needs to
// distinguish between core/FPU registers and low/high bits on 64-bit.
switch (kind) {
case DexRegisterLocation::Kind::kConstant:
case DexRegisterLocation::Kind::kInStack:
// VRegKind is ignored.
return VRegKind::kUndefined;
case DexRegisterLocation::Kind::kInRegister:
// Selects core register. For 64-bit registers, selects low 32 bits.
return VRegKind::kLongLoVReg;
case DexRegisterLocation::Kind::kInRegisterHigh:
// Selects core register. For 64-bit registers, selects high 32 bits.
return VRegKind::kLongHiVReg;
case DexRegisterLocation::Kind::kInFpuRegister:
// Selects FPU register. For 64-bit registers, selects low 32 bits.
return VRegKind::kDoubleLoVReg;
case DexRegisterLocation::Kind::kInFpuRegisterHigh:
// Selects FPU register. For 64-bit registers, selects high 32 bits.
return VRegKind::kDoubleHiVReg;
default:
LOG(FATAL) << "Unexpected vreg location " << kind;
UNREACHABLE();
}
}
void QuickExceptionHandler::SetCatchEnvironmentForOptimizedHandler(StackVisitor* stack_visitor) {
DCHECK(!is_deoptimization_);
DCHECK(*handler_quick_frame_ != nullptr) << "Method should not be called on upcall exceptions";
DCHECK(GetHandlerMethod() != nullptr && handler_method_header_->IsOptimized());
if (kDebugExceptionDelivery) {
self_->DumpStack(LOG_STREAM(INFO) << "Setting catch phis: ");
}
CodeInfo code_info(handler_method_header_);
// Find stack map of the catch block.
ArrayRef<const uint32_t> dex_pc_list = GetHandlerDexPcList();
DCHECK_GE(dex_pc_list.size(), 1u);
StackMap catch_stack_map = code_info.GetStackMapAt(GetCatchStackMapRow());
DCHECK(catch_stack_map.IsValid());
DCHECK_EQ(catch_stack_map.Row(), code_info.GetCatchStackMapForDexPc(dex_pc_list).Row());
const uint32_t catch_depth = dex_pc_list.size() - 1;
const size_t number_of_registers = stack_visitor->GetNumberOfRegisters(&code_info, catch_depth);
DexRegisterMap catch_vreg_map =
code_info.GetDexRegisterMapOf(catch_stack_map, /* first= */ 0, number_of_registers);
if (!catch_vreg_map.HasAnyLiveDexRegisters()) {
return;
}
// Find stack map of the throwing instruction.
StackMap throw_stack_map =
code_info.GetStackMapForNativePcOffset(stack_visitor->GetNativePcOffset());
DCHECK(throw_stack_map.IsValid());
const uint32_t throw_depth = stack_visitor->InlineDepth();
DCHECK_EQ(throw_depth, catch_depth);
DexRegisterMap throw_vreg_map =
code_info.GetDexRegisterMapOf(throw_stack_map, /* first= */ 0, number_of_registers);
DCHECK_EQ(throw_vreg_map.size(), catch_vreg_map.size());
// First vreg that it is part of the catch's environment.
const size_t catch_vreg_start = catch_depth == 0
? 0
: stack_visitor->GetNumberOfRegisters(&code_info, catch_depth - 1);
// We don't need to copy anything in the parent's environment.
for (size_t vreg = 0; vreg < catch_vreg_start; ++vreg) {
DexRegisterLocation::Kind catch_location_kind = catch_vreg_map[vreg].GetKind();
DCHECK(catch_location_kind == DexRegisterLocation::Kind::kNone ||
catch_location_kind == DexRegisterLocation::Kind::kConstant ||
catch_location_kind == DexRegisterLocation::Kind::kInStack)
<< "Unexpected catch_location_kind: " << catch_location_kind;
}
// Copy values between the throw and the catch.
for (size_t vreg = catch_vreg_start; vreg < catch_vreg_map.size(); ++vreg) {
DexRegisterLocation::Kind catch_location_kind = catch_vreg_map[vreg].GetKind();
if (catch_location_kind == DexRegisterLocation::Kind::kNone) {
continue;
}
// Consistency checks.
DCHECK_EQ(catch_location_kind, DexRegisterLocation::Kind::kInStack);
uint32_t vreg_value;
VRegKind vreg_kind = ToVRegKind(throw_vreg_map[vreg].GetKind());
DCHECK_NE(vreg_kind, kReferenceVReg)
<< "The fast path in GetVReg doesn't expect a kReferenceVReg.";
// Get vreg value from its current location.
bool get_vreg_success = stack_visitor->GetVReg(stack_visitor->GetMethod(),
vreg,
vreg_kind,
&vreg_value,
throw_vreg_map[vreg],
/* need_full_register_list= */ true);
CHECK(get_vreg_success) << "VReg " << vreg << " was optimized out ("
<< "method=" << ArtMethod::PrettyMethod(stack_visitor->GetMethod())
<< ", dex_pc=" << stack_visitor->GetDexPc() << ", "
<< "native_pc_offset=" << stack_visitor->GetNativePcOffset() << ")";
// Copy value to the catch phi's stack slot.
int32_t slot_offset = catch_vreg_map[vreg].GetStackOffsetInBytes();
ArtMethod** frame_top = stack_visitor->GetCurrentQuickFrame();
uint8_t* slot_address = reinterpret_cast<uint8_t*>(frame_top) + slot_offset;
uint32_t* slot_ptr = reinterpret_cast<uint32_t*>(slot_address);
*slot_ptr = vreg_value;
}
}
// Prepares deoptimization.
class DeoptimizeStackVisitor final : public StackVisitor {
public:
DeoptimizeStackVisitor(Thread* self,
Context* context,
QuickExceptionHandler* exception_handler,
bool single_frame,
bool skip_method_exit_callbacks) REQUIRES_SHARED(Locks::mutator_lock_)
: StackVisitor(self, context, StackVisitor::StackWalkKind::kIncludeInlinedFrames),
exception_handler_(exception_handler),
prev_shadow_frame_(nullptr),
stacked_shadow_frame_pushed_(false),
single_frame_deopt_(single_frame),
single_frame_done_(false),
single_frame_deopt_method_(nullptr),
single_frame_deopt_quick_method_header_(nullptr),
callee_method_(nullptr),
skip_method_exit_callbacks_(skip_method_exit_callbacks) {}
ArtMethod* GetSingleFrameDeoptMethod() const {
return single_frame_deopt_method_;
}
const OatQuickMethodHeader* GetSingleFrameDeoptQuickMethodHeader() const {
return single_frame_deopt_quick_method_header_;
}
void FinishStackWalk() REQUIRES_SHARED(Locks::mutator_lock_) {
// This is the upcall, or the next full frame in single-frame deopt, or the
// code isn't deoptimizeable. We remember the frame and last pc so that we
// may long jump to them.
exception_handler_->SetHandlerQuickFramePc(GetCurrentQuickFramePc());
exception_handler_->SetHandlerQuickFrame(GetCurrentQuickFrame());
exception_handler_->SetHandlerMethodHeader(GetCurrentOatQuickMethodHeader());
if (!stacked_shadow_frame_pushed_) {
// In case there is no deoptimized shadow frame for this upcall, we still
// need to push a nullptr to the stack since there is always a matching pop after
// the long jump.
GetThread()->PushStackedShadowFrame(nullptr,
StackedShadowFrameType::kDeoptimizationShadowFrame);
stacked_shadow_frame_pushed_ = true;
}
if (GetMethod() == nullptr) {
exception_handler_->SetFullFragmentDone(true);
} else {
CHECK(callee_method_ != nullptr) << GetMethod()->PrettyMethod(false);
exception_handler_->SetHandlerQuickArg0(reinterpret_cast<uintptr_t>(callee_method_));
}
}
bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
exception_handler_->SetHandlerFrameDepth(GetFrameDepth());
ArtMethod* method = GetMethod();
VLOG(deopt) << "Deoptimizing stack: depth: " << GetFrameDepth()
<< " at method " << ArtMethod::PrettyMethod(method);
if (method == nullptr || single_frame_done_) {
FinishStackWalk();
return false; // End stack walk.
} else if (method->IsRuntimeMethod()) {
// Ignore callee save method.
DCHECK(method->IsCalleeSaveMethod());
return true;
} else if (method->IsNative()) {
// If we return from JNI with a pending exception and want to deoptimize, we need to skip
// the native method. The top method is a runtime method, the native method comes next.
// We also deoptimize due to method instrumentation reasons from method entry / exit
// callbacks. In these cases native method is at the top of stack.
CHECK((GetFrameDepth() == 1U) || (GetFrameDepth() == 0U));
callee_method_ = method;
return true;
} else if (!single_frame_deopt_ &&
!Runtime::Current()->IsAsyncDeoptimizeable(GetOuterMethod(),
GetCurrentQuickFramePc())) {
// We hit some code that's not deoptimizeable. However, Single-frame deoptimization triggered
// from compiled code is always allowed since HDeoptimize always saves the full environment.
LOG(WARNING) << "Got request to deoptimize un-deoptimizable method "
<< method->PrettyMethod();
FinishStackWalk();
return false; // End stack walk.
} else {
// Check if a shadow frame already exists for debugger's set-local-value purpose.
const size_t frame_id = GetFrameId();
ShadowFrame* new_frame = GetThread()->FindDebuggerShadowFrame(frame_id);
const bool* updated_vregs;
CodeItemDataAccessor accessor(method->DexInstructionData());
const size_t num_regs = accessor.RegistersSize();
if (new_frame == nullptr) {
new_frame = ShadowFrame::CreateDeoptimizedFrame(num_regs, method, GetDexPc());
updated_vregs = nullptr;
} else {
updated_vregs = GetThread()->GetUpdatedVRegFlags(frame_id);
DCHECK(updated_vregs != nullptr);
}
if (GetCurrentOatQuickMethodHeader()->IsNterpMethodHeader()) {
HandleNterpDeoptimization(method, new_frame, updated_vregs);
} else {
HandleOptimizingDeoptimization(method, new_frame, updated_vregs);
}
// Update if method exit event needs to be reported. We should report exit event only if we
// have reported an entry event. So tell interpreter if/ an entry event was reported.
bool supports_exit_events =
Runtime::Current()->GetInstrumentation()->MethodSupportsExitEvents(
method, GetCurrentOatQuickMethodHeader());
new_frame->SetSkipMethodExitEvents(!supports_exit_events);
// If we are deoptimizing after method exit callback we shouldn't call the method exit
// callbacks again for the top frame. We may have to deopt after the callback if the callback
// either throws or performs other actions that require a deopt.
// We only need to skip for the top frame and the rest of the frames should still run the
// callbacks. So only do this check for the top frame.
if (GetFrameDepth() == 0U && skip_method_exit_callbacks_) {
new_frame->SetSkipMethodExitEvents(true);
// This exception was raised by method exit callbacks and we shouldn't report it to
// listeners for these exceptions.
if (GetThread()->IsExceptionPending()) {
new_frame->SetSkipNextExceptionEvent(true);
}
}
if (updated_vregs != nullptr) {
// Calling Thread::RemoveDebuggerShadowFrameMapping will also delete the updated_vregs
// array so this must come after we processed the frame.
GetThread()->RemoveDebuggerShadowFrameMapping(frame_id);
DCHECK(GetThread()->FindDebuggerShadowFrame(frame_id) == nullptr);
}
if (prev_shadow_frame_ != nullptr) {
prev_shadow_frame_->SetLink(new_frame);
} else {
// Will be popped after the long jump after DeoptimizeStack(),
// right before interpreter::EnterInterpreterFromDeoptimize().
stacked_shadow_frame_pushed_ = true;
GetThread()->PushStackedShadowFrame(
new_frame, StackedShadowFrameType::kDeoptimizationShadowFrame);
}
prev_shadow_frame_ = new_frame;
if (single_frame_deopt_ && !IsInInlinedFrame()) {
// Single-frame deopt ends at the first non-inlined frame and needs to store that method.
single_frame_done_ = true;
single_frame_deopt_method_ = method;
single_frame_deopt_quick_method_header_ = GetCurrentOatQuickMethodHeader();
}
callee_method_ = method;
return true;
}
}
private:
void HandleNterpDeoptimization(ArtMethod* m,
ShadowFrame* new_frame,
const bool* updated_vregs)
REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod** cur_quick_frame = GetCurrentQuickFrame();
StackReference<mirror::Object>* vreg_ref_base =
reinterpret_cast<StackReference<mirror::Object>*>(NterpGetReferenceArray(cur_quick_frame));
int32_t* vreg_int_base =
reinterpret_cast<int32_t*>(NterpGetRegistersArray(cur_quick_frame));
CodeItemDataAccessor accessor(m->DexInstructionData());
const uint16_t num_regs = accessor.RegistersSize();
// An nterp frame has two arrays: a dex register array and a reference array
// that shadows the dex register array but only containing references
// (non-reference dex registers have nulls). See nterp_helpers.cc.
for (size_t reg = 0; reg < num_regs; ++reg) {
if (updated_vregs != nullptr && updated_vregs[reg]) {
// Keep the value set by debugger.
continue;
}
StackReference<mirror::Object>* ref_addr = vreg_ref_base + reg;
mirror::Object* ref = ref_addr->AsMirrorPtr();
if (ref != nullptr) {
new_frame->SetVRegReference(reg, ref);
} else {
new_frame->SetVReg(reg, vreg_int_base[reg]);
}
}
}
void HandleOptimizingDeoptimization(ArtMethod* m,
ShadowFrame* new_frame,
const bool* updated_vregs)
REQUIRES_SHARED(Locks::mutator_lock_) {
const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();
CodeInfo code_info(method_header);
uintptr_t native_pc_offset = method_header->NativeQuickPcOffset(GetCurrentQuickFramePc());
StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset);
CodeItemDataAccessor accessor(m->DexInstructionData());
const size_t number_of_vregs = accessor.RegistersSize();
uint32_t register_mask = code_info.GetRegisterMaskOf(stack_map);
BitMemoryRegion stack_mask = code_info.GetStackMaskOf(stack_map);
DexRegisterMap vreg_map = IsInInlinedFrame()
? code_info.GetInlineDexRegisterMapOf(stack_map, GetCurrentInlinedFrame())
: code_info.GetDexRegisterMapOf(stack_map);
if (kIsDebugBuild || UNLIKELY(Runtime::Current()->IsJavaDebuggable())) {
CHECK_EQ(vreg_map.size(), number_of_vregs) << *Thread::Current()
<< "Deopting: " << m->PrettyMethod()
<< " inlined? "
<< std::boolalpha << IsInInlinedFrame();
}
if (vreg_map.empty()) {
return;
}
for (uint16_t vreg = 0; vreg < number_of_vregs; ++vreg) {
if (updated_vregs != nullptr && updated_vregs[vreg]) {
// Keep the value set by debugger.
continue;
}
DexRegisterLocation::Kind location = vreg_map[vreg].GetKind();
static constexpr uint32_t kDeadValue = 0xEBADDE09;
uint32_t value = kDeadValue;
bool is_reference = false;
switch (location) {
case DexRegisterLocation::Kind::kInStack: {
const int32_t offset = vreg_map[vreg].GetStackOffsetInBytes();
const uint8_t* addr = reinterpret_cast<const uint8_t*>(GetCurrentQuickFrame()) + offset;
value = *reinterpret_cast<const uint32_t*>(addr);
uint32_t bit = (offset >> 2);
if (bit < stack_mask.size_in_bits() && stack_mask.LoadBit(bit)) {
is_reference = true;
}
break;
}
case DexRegisterLocation::Kind::kInRegister:
case DexRegisterLocation::Kind::kInRegisterHigh:
case DexRegisterLocation::Kind::kInFpuRegister:
case DexRegisterLocation::Kind::kInFpuRegisterHigh: {
uint32_t reg = vreg_map[vreg].GetMachineRegister();
bool result = GetRegisterIfAccessible(reg, location, &value);
CHECK(result);
if (location == DexRegisterLocation::Kind::kInRegister) {
if (((1u << reg) & register_mask) != 0) {
is_reference = true;
}
}
break;
}
case DexRegisterLocation::Kind::kConstant: {
value = vreg_map[vreg].GetConstant();
if (value == 0) {
// Make it a reference for extra safety.
is_reference = true;
}
break;
}
case DexRegisterLocation::Kind::kNone: {
break;
}
default: {
LOG(FATAL) << "Unexpected location kind " << vreg_map[vreg].GetKind();
UNREACHABLE();
}
}
if (is_reference) {
new_frame->SetVRegReference(vreg, reinterpret_cast<mirror::Object*>(value));
} else {
new_frame->SetVReg(vreg, value);
}
}
}
static VRegKind GetVRegKind(uint16_t reg, const std::vector<int32_t>& kinds) {
return static_cast<VRegKind>(kinds[reg * 2]);
}
QuickExceptionHandler* const exception_handler_;
ShadowFrame* prev_shadow_frame_;
bool stacked_shadow_frame_pushed_;
const bool single_frame_deopt_;
bool single_frame_done_;
ArtMethod* single_frame_deopt_method_;
const OatQuickMethodHeader* single_frame_deopt_quick_method_header_;
ArtMethod* callee_method_;
// This specifies if method exit callbacks should be skipped for the top frame. We may request
// a deopt after running method exit callbacks if the callback throws or requests events that
// need a deopt.
bool skip_method_exit_callbacks_;
DISALLOW_COPY_AND_ASSIGN(DeoptimizeStackVisitor);
};
void QuickExceptionHandler::PrepareForLongJumpToInvokeStubOrInterpreterBridge() {
if (full_fragment_done_) {
// Restore deoptimization exception. When returning from the invoke stub,
// ArtMethod::Invoke() will see the special exception to know deoptimization
// is needed.
self_->SetException(Thread::GetDeoptimizationException());
} else {
// PC needs to be of the quick-to-interpreter bridge.
int32_t offset;
offset = GetThreadOffset<kRuntimePointerSize>(kQuickQuickToInterpreterBridge).Int32Value();
handler_quick_frame_pc_ = *reinterpret_cast<uintptr_t*>(
reinterpret_cast<uint8_t*>(self_) + offset);
}
}
void QuickExceptionHandler::DeoptimizeStack(bool skip_method_exit_callbacks) {
DCHECK(is_deoptimization_);
if (kDebugExceptionDelivery) {
self_->DumpStack(LOG_STREAM(INFO) << "Deoptimizing: ");
}
DeoptimizeStackVisitor visitor(self_, context_, this, false, skip_method_exit_callbacks);
visitor.WalkStack(true);
PrepareForLongJumpToInvokeStubOrInterpreterBridge();
}
void QuickExceptionHandler::DeoptimizeSingleFrame(DeoptimizationKind kind) {
DCHECK(is_deoptimization_);
// This deopt is requested while still executing the method. We haven't run method exit callbacks
// yet, so don't skip them.
DeoptimizeStackVisitor visitor(
self_, context_, this, true, /* skip_method_exit_callbacks= */ false);
visitor.WalkStack(true);
// Compiled code made an explicit deoptimization.
ArtMethod* deopt_method = visitor.GetSingleFrameDeoptMethod();
SCOPED_TRACE << "Deoptimizing "
<< deopt_method->PrettyMethod()
<< ": " << GetDeoptimizationKindName(kind);
DCHECK(deopt_method != nullptr);
if (VLOG_IS_ON(deopt) || kDebugExceptionDelivery) {
LOG(INFO) << "Single-frame deopting: "
<< deopt_method->PrettyMethod()
<< " due to "
<< GetDeoptimizationKindName(kind);
DumpFramesWithType(self_, /* details= */ true);
}
// When deoptimizing for debug support the optimized code is still valid and
// can be reused when debugging support (like breakpoints) are no longer
// needed fot this method.
if (Runtime::Current()->UseJitCompilation() && (kind != DeoptimizationKind::kDebugging)) {
Runtime::Current()->GetJit()->GetCodeCache()->InvalidateCompiledCodeFor(
deopt_method, visitor.GetSingleFrameDeoptQuickMethodHeader());
} else {
Runtime::Current()->GetInstrumentation()->InitializeMethodsCode(
deopt_method, /*aot_code=*/ nullptr);
}
PrepareForLongJumpToInvokeStubOrInterpreterBridge();
}
void QuickExceptionHandler::DeoptimizePartialFragmentFixup() {
CHECK(handler_quick_frame_ != nullptr);
// Architecture-dependent work. This is to get the LR right for x86 and x86-64.
if (kRuntimeISA == InstructionSet::kX86 || kRuntimeISA == InstructionSet::kX86_64) {
// On x86, the return address is on the stack, so just reuse it. Otherwise we would have to
// change how longjump works.
handler_quick_frame_ = reinterpret_cast<ArtMethod**>(
reinterpret_cast<uintptr_t>(handler_quick_frame_) - sizeof(void*));
}
}
void QuickExceptionHandler::DoLongJump(bool smash_caller_saves) {
// Place context back on thread so it will be available when we continue.
self_->ReleaseLongJumpContext(context_);
context_->SetSP(reinterpret_cast<uintptr_t>(handler_quick_frame_));
CHECK_NE(handler_quick_frame_pc_, 0u);
context_->SetPC(handler_quick_frame_pc_);
context_->SetArg0(handler_quick_arg0_);
if (smash_caller_saves) {
context_->SmashCallerSaves();
}
if (!is_deoptimization_ &&
handler_method_header_ != nullptr &&
handler_method_header_->IsNterpMethodHeader()) {
// Interpreter procceses one method at a time i.e. not inlining
DCHECK(handler_dex_pc_list_.has_value());
DCHECK_EQ(handler_dex_pc_list_->size(), 1u) << "We shouldn't have any inlined frames.";
context_->SetNterpDexPC(reinterpret_cast<uintptr_t>(
GetHandlerMethod()->DexInstructions().Insns() + handler_dex_pc_list_->front()));
}
// Clear the dex_pc list so as not to leak memory.
handler_dex_pc_list_.reset();
context_->DoLongJump();
UNREACHABLE();
}
void QuickExceptionHandler::DumpFramesWithType(Thread* self, bool details) {
StackVisitor::WalkStack(
[&](const art::StackVisitor* stack_visitor) REQUIRES_SHARED(Locks::mutator_lock_) {
ArtMethod* method = stack_visitor->GetMethod();
if (details) {
LOG(INFO) << "|> pc = " << std::hex << stack_visitor->GetCurrentQuickFramePc();
LOG(INFO) << "|> addr = " << std::hex
<< reinterpret_cast<uintptr_t>(stack_visitor->GetCurrentQuickFrame());
if (stack_visitor->GetCurrentQuickFrame() != nullptr && method != nullptr) {
LOG(INFO) << "|> ret = " << std::hex << stack_visitor->GetReturnPc();
}
}
if (method == nullptr) {
// Transition, do go on, we want to unwind over bridges, all the way.
if (details) {
LOG(INFO) << "N <transition>";
}
return true;
} else if (method->IsRuntimeMethod()) {
if (details) {
LOG(INFO) << "R " << method->PrettyMethod(true);
}
return true;
} else {
bool is_shadow = stack_visitor->GetCurrentShadowFrame() != nullptr;
LOG(INFO) << (is_shadow ? "S" : "Q")
<< ((!is_shadow && stack_visitor->IsInInlinedFrame()) ? "i" : " ")
<< " "
<< method->PrettyMethod(true);
return true; // Go on.
}
},
self,
/* context= */ nullptr,
art::StackVisitor::StackWalkKind::kIncludeInlinedFrames);
}
} // namespace art