text: //===-- sanitizer_fuchsia.cc ---------------------------------------------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===---------------------------------------------------------------------===//
  //
  // This file is shared between AddressSanitizer and other sanitizer
  // run-time libraries and implements Fuchsia-specific functions from
  // sanitizer_common.h.
  //===---------------------------------------------------------------------===//
  
  #include "sanitizer_fuchsia.h"
  #if SANITIZER_FUCHSIA
  
  #include "sanitizer_common.h"
  #include "sanitizer_libc.h"
  #include "sanitizer_mutex.h"
  #include "sanitizer_stacktrace.h"
  
  #include <limits.h>
  #include <pthread.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <unwind.h>
  #include <zircon/errors.h>
  #include <zircon/process.h>
  #include <zircon/syscalls.h>
  
  namespace __sanitizer {
  
  void NORETURN internal__exit(int exitcode) { _zx_process_exit(exitcode); }
  
  uptr internal_sched_yield() {
    zx_status_t status = _zx_nanosleep(0);
    CHECK_EQ(status, ZX_OK);
    return 0;  // Why doesn't this return void?
  }
  
  static void internal_nanosleep(zx_time_t ns) {
    zx_status_t status = _zx_nanosleep(_zx_deadline_after(ns));
    CHECK_EQ(status, ZX_OK);
  }
  
  unsigned int internal_sleep(unsigned int seconds) {
    internal_nanosleep(ZX_SEC(seconds));
    return 0;
  }
  
  u64 NanoTime() { return _zx_time_get(ZX_CLOCK_UTC); }
  
  u64 MonotonicNanoTime() { return _zx_time_get(ZX_CLOCK_MONOTONIC); }
  
  uptr internal_getpid() {
    zx_info_handle_basic_t info;
    zx_status_t status =
        _zx_object_get_info(_zx_process_self(), ZX_INFO_HANDLE_BASIC, &info,
                            sizeof(info), NULL, NULL);
    CHECK_EQ(status, ZX_OK);
    uptr pid = static_cast<uptr>(info.koid);
    CHECK_EQ(pid, info.koid);
    return pid;
  }
  
  uptr GetThreadSelf() { return reinterpret_cast<uptr>(thrd_current()); }
  
  uptr GetTid() { return GetThreadSelf(); }
  
  void Abort() { abort(); }
  
  int Atexit(void (*function)(void)) { return atexit(function); }
  
  void SleepForSeconds(int seconds) { internal_sleep(seconds); }
  
  void SleepForMillis(int millis) { internal_nanosleep(ZX_MSEC(millis)); }
  
  void GetThreadStackTopAndBottom(bool, uptr *stack_top, uptr *stack_bottom) {
    pthread_attr_t attr;
    CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
    void *base;
    size_t size;
    CHECK_EQ(pthread_attr_getstack(&attr, &base, &size), 0);
    CHECK_EQ(pthread_attr_destroy(&attr), 0);
  
    *stack_bottom = reinterpret_cast<uptr>(base);
    *stack_top = *stack_bottom + size;
  }
  
  void MaybeReexec() {}
  void PrepareForSandboxing(__sanitizer_sandbox_arguments *args) {}
  void DisableCoreDumperIfNecessary() {}
  void InstallDeadlySignalHandlers(SignalHandlerType handler) {}
  void StartReportDeadlySignal() {}
  void ReportDeadlySignal(const SignalContext &sig, u32 tid,
                          UnwindSignalStackCallbackType unwind,
                          const void *unwind_context) {}
  void SetAlternateSignalStack() {}
  void UnsetAlternateSignalStack() {}
  void InitTlsSize() {}
  
  void PrintModuleMap() {}
  
  bool SignalContext::IsStackOverflow() const { return false; }
  void SignalContext::DumpAllRegisters(void *context) { UNIMPLEMENTED(); }
  const char *SignalContext::Describe() const { UNIMPLEMENTED(); }
  
  struct UnwindTraceArg {
    BufferedStackTrace *stack;
    u32 max_depth;
  };
  
  _Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, void *param) {
    UnwindTraceArg *arg = static_cast<UnwindTraceArg *>(param);
    CHECK_LT(arg->stack->size, arg->max_depth);
    uptr pc = _Unwind_GetIP(ctx);
    if (pc < PAGE_SIZE) return _URC_NORMAL_STOP;
    arg->stack->trace_buffer[arg->stack->size++] = pc;
    return (arg->stack->size == arg->max_depth ? _URC_NORMAL_STOP
                                               : _URC_NO_REASON);
  }
  
  void BufferedStackTrace::SlowUnwindStack(uptr pc, u32 max_depth) {
    CHECK_GE(max_depth, 2);
    size = 0;
    UnwindTraceArg arg = {this, Min(max_depth + 1, kStackTraceMax)};
    _Unwind_Backtrace(Unwind_Trace, &arg);
    CHECK_GT(size, 0);
    // We need to pop a few frames so that pc is on top.
    uptr to_pop = LocatePcInTrace(pc);
    // trace_buffer[0] belongs to the current function so we always pop it,
    // unless there is only 1 frame in the stack trace (1 frame is always better
    // than 0!).
    PopStackFrames(Min(to_pop, static_cast<uptr>(1)));
    trace_buffer[0] = pc;
  }
  
  void BufferedStackTrace::SlowUnwindStackWithContext(uptr pc, void *context,
                                                      u32 max_depth) {
    CHECK_NE(context, nullptr);
    UNREACHABLE("signal context doesn't exist");
  }
  
  enum MutexState : int { MtxUnlocked = 0, MtxLocked = 1, MtxSleeping = 2 };
  
  BlockingMutex::BlockingMutex() {
    // NOTE!  It's important that this use internal_memset, because plain
    // memset might be intercepted (e.g., actually be __asan_memset).
    // Defining this so the compiler initializes each field, e.g.:
    //   BlockingMutex::BlockingMutex() : BlockingMutex(LINKER_INITIALIZED) {}
    // might result in the compiler generating a call to memset, which would
    // have the same problem.
    internal_memset(this, 0, sizeof(*this));
  }
  
  void BlockingMutex::Lock() {
    CHECK_EQ(owner_, 0);
    atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
    if (atomic_exchange(m, MtxLocked, memory_order_acquire) == MtxUnlocked)
      return;
    while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked) {
      zx_status_t status = _zx_futex_wait(reinterpret_cast<zx_futex_t *>(m),
                                          MtxSleeping, ZX_TIME_INFINITE);
      if (status != ZX_ERR_BAD_STATE)  // Normal race.
        CHECK_EQ(status, ZX_OK);
    }
  }
  
  void BlockingMutex::Unlock() {
    atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
    u32 v = atomic_exchange(m, MtxUnlocked, memory_order_release);
    CHECK_NE(v, MtxUnlocked);
    if (v == MtxSleeping) {
      zx_status_t status = _zx_futex_wake(reinterpret_cast<zx_futex_t *>(m), 1);
      CHECK_EQ(status, ZX_OK);
    }
  }
  
  void BlockingMutex::CheckLocked() {
    atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
    CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed));
  }
  
  uptr GetPageSize() { return PAGE_SIZE; }
  
  uptr GetMmapGranularity() { return PAGE_SIZE; }
  
  sanitizer_shadow_bounds_t ShadowBounds;
  
  uptr GetMaxUserVirtualAddress() {
    ShadowBounds = __sanitizer_shadow_bounds();
    return ShadowBounds.memory_limit - 1;
  }
  
  uptr GetMaxVirtualAddress() { return GetMaxUserVirtualAddress(); }
  
  static void *DoAnonymousMmapOrDie(uptr size, const char *mem_type,
                                    bool raw_report, bool die_for_nomem) {
    size = RoundUpTo(size, PAGE_SIZE);
  
    zx_handle_t vmo;
    zx_status_t status = _zx_vmo_create(size, 0, &vmo);
    if (status != ZX_OK) {
      if (status != ZX_ERR_NO_MEMORY || die_for_nomem)
        ReportMmapFailureAndDie(size, mem_type, "zx_vmo_create", status,
                                raw_report);
      return nullptr;
    }
    _zx_object_set_property(vmo, ZX_PROP_NAME, mem_type,
                            internal_strlen(mem_type));
  
    // TODO(mcgrathr): Maybe allocate a VMAR for all sanitizer heap and use that?
    uintptr_t addr;
    status = _zx_vmar_map(_zx_vmar_root_self(), 0, vmo, 0, size,
                          ZX_VM_FLAG_PERM_READ | ZX_VM_FLAG_PERM_WRITE, &addr);
    _zx_handle_close(vmo);
  
    if (status != ZX_OK) {
      if (status != ZX_ERR_NO_MEMORY || die_for_nomem)
        ReportMmapFailureAndDie(size, mem_type, "zx_vmar_map", status,
                                raw_report);
      return nullptr;
    }
  
    IncreaseTotalMmap(size);
  
    return reinterpret_cast<void *>(addr);
  }
  
  void *MmapOrDie(uptr size, const char *mem_type, bool raw_report) {
    return DoAnonymousMmapOrDie(size, mem_type, raw_report, true);
  }
  
  void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
    return MmapOrDie(size, mem_type);
  }
  
  void *MmapOrDieOnFatalError(uptr size, const char *mem_type) {
    return DoAnonymousMmapOrDie(size, mem_type, false, false);
  }
  
  uptr ReservedAddressRange::Init(uptr init_size, const char *name,
                                  uptr fixed_addr) {
    init_size = RoundUpTo(init_size, PAGE_SIZE);
    DCHECK_EQ(os_handle_, ZX_HANDLE_INVALID);
    uintptr_t base;
    zx_handle_t vmar;
    zx_status_t status =
        _zx_vmar_allocate(_zx_vmar_root_self(), 0, init_size,
                          ZX_VM_FLAG_CAN_MAP_READ | ZX_VM_FLAG_CAN_MAP_WRITE |
                              ZX_VM_FLAG_CAN_MAP_SPECIFIC,
                          &vmar, &base);
    if (status != ZX_OK)
      ReportMmapFailureAndDie(init_size, name, "zx_vmar_allocate", status);
    base_ = reinterpret_cast<void *>(base);
    size_ = init_size;
    name_ = name;
    os_handle_ = vmar;
  
    return reinterpret_cast<uptr>(base_);
  }
  
  static uptr DoMmapFixedOrDie(zx_handle_t vmar, uptr fixed_addr, uptr map_size,
                               void *base, const char *name, bool die_for_nomem) {
    uptr offset = fixed_addr - reinterpret_cast<uptr>(base);
    map_size = RoundUpTo(map_size, PAGE_SIZE);
    zx_handle_t vmo;
    zx_status_t status = _zx_vmo_create(map_size, 0, &vmo);
    if (status != ZX_OK) {
      if (status != ZX_ERR_NO_MEMORY || die_for_nomem)
        ReportMmapFailureAndDie(map_size, name, "zx_vmo_create", status);
      return 0;
    }
    _zx_object_set_property(vmo, ZX_PROP_NAME, name, sizeof(name) - 1);
    DCHECK_GE(base + size_, map_size + offset);
    uintptr_t addr;
  
    status = _zx_vmar_map(
        vmar, offset, vmo, 0, map_size,
        ZX_VM_FLAG_PERM_READ | ZX_VM_FLAG_PERM_WRITE | ZX_VM_FLAG_SPECIFIC,
        &addr);
    _zx_handle_close(vmo);
    if (status != ZX_OK) {
      if (status != ZX_ERR_NO_MEMORY || die_for_nomem) {
        ReportMmapFailureAndDie(map_size, name, "zx_vmar_map", status);
      }
      return 0;
    }
    IncreaseTotalMmap(map_size);
    return addr;
  }
  
  uptr ReservedAddressRange::Map(uptr fixed_addr, uptr map_size) {
    return DoMmapFixedOrDie(os_handle_, fixed_addr, map_size, base_,
                            name_, false);
  }
  
  uptr ReservedAddressRange::MapOrDie(uptr fixed_addr, uptr map_size) {
    return DoMmapFixedOrDie(os_handle_, fixed_addr, map_size, base_,
                            name_, true);
  }
  
  void UnmapOrDieVmar(void *addr, uptr size, zx_handle_t target_vmar) {
    if (!addr || !size) return;
    size = RoundUpTo(size, PAGE_SIZE);
  
    zx_status_t status =
        _zx_vmar_unmap(target_vmar, reinterpret_cast<uintptr_t>(addr), size);
    if (status != ZX_OK) {
      Report("ERROR: %s failed to deallocate 0x%zx (%zd) bytes at address %p\n",
             SanitizerToolName, size, size, addr);
      CHECK("unable to unmap" && 0);
    }
  
    DecreaseTotalMmap(size);
  }
  
  void ReservedAddressRange::Unmap(uptr fixed_addr, uptr size) {
    uptr offset = fixed_addr - reinterpret_cast<uptr>(base_);
    uptr addr = reinterpret_cast<uptr>(base_) + offset;
    void *addr_as_void = reinterpret_cast<void *>(addr);
    uptr base_as_uptr = reinterpret_cast<uptr>(base_);
    // Only unmap at the beginning or end of the range.
    CHECK((addr_as_void == base_) || (addr + size == base_as_uptr + size_));
    CHECK_LE(size, size_);
    UnmapOrDieVmar(reinterpret_cast<void *>(addr), size,
                   static_cast<zx_handle_t>(os_handle_));
    if (addr_as_void == base_) {
      base_ = reinterpret_cast<void *>(addr + size);
    }
    size_ = size_ - size;
  }
  
  // This should never be called.
  void *MmapFixedNoAccess(uptr fixed_addr, uptr size, const char *name) {
    UNIMPLEMENTED();
  }
  
  void *MmapAlignedOrDieOnFatalError(uptr size, uptr alignment,
                                     const char *mem_type) {
    CHECK_GE(size, PAGE_SIZE);
    CHECK(IsPowerOfTwo(size));
    CHECK(IsPowerOfTwo(alignment));
  
    zx_handle_t vmo;
    zx_status_t status = _zx_vmo_create(size, 0, &vmo);
    if (status != ZX_OK) {
      if (status != ZX_ERR_NO_MEMORY)
        ReportMmapFailureAndDie(size, mem_type, "zx_vmo_create", status, false);
      return nullptr;
    }
    _zx_object_set_property(vmo, ZX_PROP_NAME, mem_type,
                            internal_strlen(mem_type));
  
    // TODO(mcgrathr): Maybe allocate a VMAR for all sanitizer heap and use that?
  
    // Map a larger size to get a chunk of address space big enough that
    // it surely contains an aligned region of the requested size.  Then
    // overwrite the aligned middle portion with a mapping from the
    // beginning of the VMO, and unmap the excess before and after.
    size_t map_size = size + alignment;
    uintptr_t addr;
    status = _zx_vmar_map(_zx_vmar_root_self(), 0, vmo, 0, map_size,
                          ZX_VM_FLAG_PERM_READ | ZX_VM_FLAG_PERM_WRITE, &addr);
    if (status == ZX_OK) {
      uintptr_t map_addr = addr;
      uintptr_t map_end = map_addr + map_size;
      addr = RoundUpTo(map_addr, alignment);
      uintptr_t end = addr + size;
      if (addr != map_addr) {
        zx_info_vmar_t info;
        status = _zx_object_get_info(_zx_vmar_root_self(), ZX_INFO_VMAR, &info,
                                     sizeof(info), NULL, NULL);
        if (status == ZX_OK) {
          uintptr_t new_addr;
          status =
              _zx_vmar_map(_zx_vmar_root_self(), addr - info.base, vmo, 0, size,
                           ZX_VM_FLAG_PERM_READ | ZX_VM_FLAG_PERM_WRITE |
                               ZX_VM_FLAG_SPECIFIC_OVERWRITE,
                           &new_addr);
          if (status == ZX_OK) CHECK_EQ(new_addr, addr);
        }
      }
      if (status == ZX_OK && addr != map_addr)
        status = _zx_vmar_unmap(_zx_vmar_root_self(), map_addr, addr - map_addr);
      if (status == ZX_OK && end != map_end)
        status = _zx_vmar_unmap(_zx_vmar_root_self(), end, map_end - end);
    }
    _zx_handle_close(vmo);
  
    if (status != ZX_OK) {
      if (status != ZX_ERR_NO_MEMORY)
        ReportMmapFailureAndDie(size, mem_type, "zx_vmar_map", status, false);
      return nullptr;
    }
  
    IncreaseTotalMmap(size);
  
    return reinterpret_cast<void *>(addr);
  }
  
  void UnmapOrDie(void *addr, uptr size) {
    UnmapOrDieVmar(addr, size, _zx_vmar_root_self());
  }
  
  // This is used on the shadow mapping, which cannot be changed.
  // Zircon doesn't have anything like MADV_DONTNEED.
  void ReleaseMemoryPagesToOS(uptr beg, uptr end) {}
  
  void DumpProcessMap() {
    // TODO(mcgrathr): write it
    return;
  }
  
  bool IsAccessibleMemoryRange(uptr beg, uptr size) {
    // TODO(mcgrathr): Figure out a better way.
    zx_handle_t vmo;
    zx_status_t status = _zx_vmo_create(size, 0, &vmo);
    if (status == ZX_OK) {
      while (size > 0) {
        size_t wrote;
        status = _zx_vmo_write(vmo, reinterpret_cast<const void *>(beg), 0, size,
                               &wrote);
        if (status != ZX_OK) break;
        CHECK_GT(wrote, 0);
        CHECK_LE(wrote, size);
        beg += wrote;
        size -= wrote;
      }
      _zx_handle_close(vmo);
    }
    return status == ZX_OK;
  }
  
  // FIXME implement on this platform.
  void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size) {}
  
  bool ReadFileToBuffer(const char *file_name, char **buff, uptr *buff_size,
                        uptr *read_len, uptr max_len, error_t *errno_p) {
    zx_handle_t vmo;
    zx_status_t status = __sanitizer_get_configuration(file_name, &vmo);
    if (status == ZX_OK) {
      uint64_t vmo_size;
      status = _zx_vmo_get_size(vmo, &vmo_size);
      if (status == ZX_OK) {
        if (vmo_size < max_len) max_len = vmo_size;
        size_t map_size = RoundUpTo(max_len, PAGE_SIZE);
        uintptr_t addr;
        status = _zx_vmar_map(_zx_vmar_root_self(), 0, vmo, 0, map_size,
                              ZX_VM_FLAG_PERM_READ, &addr);
        if (status == ZX_OK) {
          *buff = reinterpret_cast<char *>(addr);
          *buff_size = map_size;
          *read_len = max_len;
        }
      }
      _zx_handle_close(vmo);
    }
    if (status != ZX_OK && errno_p) *errno_p = status;
    return status == ZX_OK;
  }
  
  void RawWrite(const char *buffer) {
    __sanitizer_log_write(buffer, internal_strlen(buffer));
  }
  
  void CatastrophicErrorWrite(const char *buffer, uptr length) {
    __sanitizer_log_write(buffer, length);
  }
  
  char **StoredArgv;
  char **StoredEnviron;
  
  char **GetArgv() { return StoredArgv; }
  
  const char *GetEnv(const char *name) {
    if (StoredEnviron) {
      uptr NameLen = internal_strlen(name);
      for (char **Env = StoredEnviron; *Env != 0; Env++) {
        if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
          return (*Env) + NameLen + 1;
      }
    }
    return nullptr;
  }
  
  uptr ReadBinaryName(/*out*/ char *buf, uptr buf_len) {
    const char *argv0 = StoredArgv[0];
    if (!argv0) argv0 = "<UNKNOWN>";
    internal_strncpy(buf, argv0, buf_len);
    return internal_strlen(buf);
  }
  
  uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
    return ReadBinaryName(buf, buf_len);
  }
  
  uptr MainThreadStackBase, MainThreadStackSize;
  
  bool GetRandom(void *buffer, uptr length, bool blocking) {
    CHECK_LE(length, ZX_CPRNG_DRAW_MAX_LEN);
    size_t size;
    CHECK_EQ(_zx_cprng_draw(buffer, length, &size), ZX_OK);
    CHECK_EQ(size, length);
    return true;
  }
  
  u32 GetNumberOfCPUs() {
    return zx_system_get_num_cpus();
  }
  
  uptr GetRSS() { UNIMPLEMENTED(); }
  
  }  // namespace __sanitizer
  
  using namespace __sanitizer;  // NOLINT
  
  extern "C" {
  void __sanitizer_startup_hook(int argc, char **argv, char **envp,
                                void *stack_base, size_t stack_size) {
    __sanitizer::StoredArgv = argv;
    __sanitizer::StoredEnviron = envp;
    __sanitizer::MainThreadStackBase = reinterpret_cast<uintptr_t>(stack_base);
    __sanitizer::MainThreadStackSize = stack_size;
  }
  
  void __sanitizer_set_report_path(const char *path) {
    // Handle the initialization code in each sanitizer, but no other calls.
    // This setting is never consulted on Fuchsia.
    DCHECK_EQ(path, common_flags()->log_path);
  }
  
  void __sanitizer_set_report_fd(void *fd) {
    UNREACHABLE("not available on Fuchsia");
  }
  }  // extern "C"
  
  #endif  // SANITIZER_FUCHSIA
  