tick-sample.cc | Explore in Territory

// Copyright 2013 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/profiler/tick-sample.h"

#include <cinttypes>

#include "include/v8-profiler.h"
#include "src/base/sanitizer/asan.h"
#include "src/base/sanitizer/msan.h"
#include "src/execution/embedder-state.h"
#include "src/execution/frames-inl.h"
#include "src/execution/simulator.h"
#include "src/execution/vm-state-inl.h"
#include "src/heap/heap-inl.h"  // For Heap::code_range.
#include "src/logging/counters.h"
#include "src/profiler/profiler-stats.h"

namespace v8 {
namespace internal {
namespace {

bool IsSamePage(i::Address ptr1, i::Address ptr2) { … }

// Check if the code at specified address could potentially be a
// frame setup code.
bool IsNoFrameRegion(i::Address address) { … }

#if defined(USE_SIMULATOR)
class SimulatorHelper {
 public:
  // Returns true if register values were successfully retrieved
  // from the simulator, otherwise returns false.
  static bool FillRegisters(Isolate* isolate, v8::RegisterState* state);
};

bool SimulatorHelper::FillRegisters(Isolate* isolate,
                                    v8::RegisterState* state) {
  Simulator* simulator = isolate->thread_local_top()->simulator_;
  // Check if there is active simulator.
  if (simulator == nullptr) return false;
#if V8_TARGET_ARCH_ARM
  if (!simulator->has_bad_pc()) {
    state->pc = reinterpret_cast<void*>(simulator->get_pc());
  }
  state->sp = reinterpret_cast<void*>(simulator->get_register(Simulator::sp));
  state->fp = reinterpret_cast<void*>(simulator->get_register(Simulator::r11));
  state->lr = reinterpret_cast<void*>(simulator->get_register(Simulator::lr));
#elif V8_TARGET_ARCH_ARM64
  state->pc = reinterpret_cast<void*>(simulator->pc());
  state->sp = reinterpret_cast<void*>(simulator->sp());
  state->fp = reinterpret_cast<void*>(simulator->fp());
  state->lr = reinterpret_cast<void*>(simulator->lr());
#elif V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_LOONG64
  if (!simulator->has_bad_pc()) {
    state->pc = reinterpret_cast<void*>(simulator->get_pc());
  }
  state->sp = reinterpret_cast<void*>(simulator->get_register(Simulator::sp));
  state->fp = reinterpret_cast<void*>(simulator->get_register(Simulator::fp));
#elif V8_TARGET_ARCH_PPC64
  if (!simulator->has_bad_pc()) {
    state->pc = reinterpret_cast<void*>(simulator->get_pc());
  }
  state->sp = reinterpret_cast<void*>(simulator->get_register(Simulator::sp));
  state->fp = reinterpret_cast<void*>(simulator->get_register(Simulator::fp));
  state->lr = reinterpret_cast<void*>(simulator->get_lr());
#elif V8_TARGET_ARCH_S390
  if (!simulator->has_bad_pc()) {
    state->pc = reinterpret_cast<void*>(simulator->get_pc());
  }
  state->sp = reinterpret_cast<void*>(simulator->get_register(Simulator::sp));
  state->fp = reinterpret_cast<void*>(simulator->get_register(Simulator::fp));
  state->lr = reinterpret_cast<void*>(simulator->get_register(Simulator::ra));
#elif V8_TARGET_ARCH_RISCV64
  if (!simulator->has_bad_pc()) {
    state->pc = reinterpret_cast<void*>(simulator->get_pc());
  }
  state->sp = reinterpret_cast<void*>(simulator->get_register(Simulator::sp));
  state->fp = reinterpret_cast<void*>(simulator->get_register(Simulator::fp));
  state->lr = reinterpret_cast<void*>(simulator->get_register(Simulator::ra));
#elif V8_TARGET_ARCH_RISCV32
  if (!simulator->has_bad_pc()) {
    state->pc = reinterpret_cast<void*>(simulator->get_pc());
  }
  state->sp = reinterpret_cast<void*>(simulator->get_register(Simulator::sp));
  state->fp = reinterpret_cast<void*>(simulator->get_register(Simulator::fp));
  state->lr = reinterpret_cast<void*>(simulator->get_register(Simulator::ra));
#endif
  if (state->sp == 0 || state->fp == 0) {
    // It possible that the simulator is interrupted while it is updating
    // the sp or fp register. ARM64 simulator does this in two steps:
    // first setting it to zero and then setting it to the new value.
    // Bailout if sp/fp doesn't contain the new value.
    //
    // FIXME: The above doesn't really solve the issue.
    // If a 64-bit target is executed on a 32-bit host even the final
    // write is non-atomic, so it might obtain a half of the result.
    // Moreover as long as the register set code uses memcpy (as of now),
    // it is not guaranteed to be atomic even when both host and target
    // are of same bitness.
    return false;
  }
  return true;
}
#endif  // USE_SIMULATOR

}  // namespace

DISABLE_ASAN void TickSample::Init(Isolate* v8_isolate,
                                   const RegisterState& reg_state,
                                   RecordCEntryFrame record_c_entry_frame,
                                   bool update_stats,
                                   bool use_simulator_reg_state,
                                   base::TimeDelta sampling_interval) { … }

// IMPORTANT: 'GetStackSample' is sensitive to stack overflows. For this reason
// we try not to use any function/method marked as V8_EXPORT_PRIVATE with their
// only use-site in 'GetStackSample': The resulting linker stub needs quite
// a bit of stack space and has caused stack overflow crashes in the past.
bool TickSample::GetStackSample(Isolate* v8_isolate, RegisterState* regs,
                                RecordCEntryFrame record_c_entry_frame,
                                void** frames, size_t frames_limit,
                                v8::SampleInfo* sample_info,
                                StateTag* out_state,
                                bool use_simulator_reg_state) { … }

void TickSample::print() const { … }

}  // namespace internal
}  // namespace v8
chromium/v8/src/profiler/tick-sample.cc
