master
  1//===-- sanitizer_fuchsia.cpp ---------------------------------------------===//
  2//
  3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4// See https://llvm.org/LICENSE.txt for license information.
  5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6//
  7//===----------------------------------------------------------------------===//
  8//
  9// This file is shared between AddressSanitizer and other sanitizer
 10// run-time libraries and implements Fuchsia-specific functions from
 11// sanitizer_common.h.
 12//===----------------------------------------------------------------------===//
 13
 14#include "sanitizer_fuchsia.h"
 15#if SANITIZER_FUCHSIA
 16
 17#  include <pthread.h>
 18#  include <stdlib.h>
 19#  include <unistd.h>
 20#  include <zircon/errors.h>
 21#  include <zircon/process.h>
 22#  include <zircon/syscalls.h>
 23#  include <zircon/utc.h>
 24
 25#  include "sanitizer_common.h"
 26#  include "sanitizer_interface_internal.h"
 27#  include "sanitizer_libc.h"
 28#  include "sanitizer_mutex.h"
 29
 30namespace __sanitizer {
 31
 32void NORETURN internal__exit(int exitcode) { _zx_process_exit(exitcode); }
 33
 34uptr internal_sched_yield() {
 35  zx_status_t status = _zx_thread_legacy_yield(0u);
 36  CHECK_EQ(status, ZX_OK);
 37  return 0;  // Why doesn't this return void?
 38}
 39
 40void internal_usleep(u64 useconds) {
 41  zx_status_t status = _zx_nanosleep(_zx_deadline_after(ZX_USEC(useconds)));
 42  CHECK_EQ(status, ZX_OK);
 43}
 44
 45u64 NanoTime() {
 46  zx_handle_t utc_clock = _zx_utc_reference_get();
 47  CHECK_NE(utc_clock, ZX_HANDLE_INVALID);
 48  zx_time_t time;
 49  zx_status_t status = _zx_clock_read(utc_clock, &time);
 50  CHECK_EQ(status, ZX_OK);
 51  return time;
 52}
 53
 54u64 MonotonicNanoTime() { return _zx_clock_get_monotonic(); }
 55
 56uptr internal_getpid() {
 57  zx_info_handle_basic_t info;
 58  zx_status_t status =
 59      _zx_object_get_info(_zx_process_self(), ZX_INFO_HANDLE_BASIC, &info,
 60                          sizeof(info), NULL, NULL);
 61  CHECK_EQ(status, ZX_OK);
 62  uptr pid = static_cast<uptr>(info.koid);
 63  CHECK_EQ(pid, info.koid);
 64  return pid;
 65}
 66
 67int internal_dlinfo(void *handle, int request, void *p) { UNIMPLEMENTED(); }
 68
 69uptr GetThreadSelf() { return reinterpret_cast<uptr>(thrd_current()); }
 70
 71tid_t GetTid() { return GetThreadSelf(); }
 72
 73void Abort() { abort(); }
 74
 75int Atexit(void (*function)(void)) { return atexit(function); }
 76
 77void GetThreadStackTopAndBottom(bool, uptr *stack_top, uptr *stack_bottom) {
 78  pthread_attr_t attr;
 79  CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
 80  void *base;
 81  size_t size;
 82  CHECK_EQ(pthread_attr_getstack(&attr, &base, &size), 0);
 83  CHECK_EQ(pthread_attr_destroy(&attr), 0);
 84
 85  *stack_bottom = reinterpret_cast<uptr>(base);
 86  *stack_top = *stack_bottom + size;
 87}
 88
 89void InitializePlatformEarly() {}
 90void CheckASLR() {}
 91void CheckMPROTECT() {}
 92void PlatformPrepareForSandboxing(void *args) {}
 93void DisableCoreDumperIfNecessary() {}
 94void InstallDeadlySignalHandlers(SignalHandlerType handler) {}
 95void SetAlternateSignalStack() {}
 96void UnsetAlternateSignalStack() {}
 97
 98bool SignalContext::IsStackOverflow() const { return false; }
 99void SignalContext::DumpAllRegisters(void *context) { UNIMPLEMENTED(); }
100const char *SignalContext::Describe() const { UNIMPLEMENTED(); }
101
102void FutexWait(atomic_uint32_t *p, u32 cmp) {
103  zx_status_t status = _zx_futex_wait(reinterpret_cast<zx_futex_t *>(p), cmp,
104                                      ZX_HANDLE_INVALID, ZX_TIME_INFINITE);
105  if (status != ZX_ERR_BAD_STATE)  // Normal race.
106    CHECK_EQ(status, ZX_OK);
107}
108
109void FutexWake(atomic_uint32_t *p, u32 count) {
110  zx_status_t status = _zx_futex_wake(reinterpret_cast<zx_futex_t *>(p), count);
111  CHECK_EQ(status, ZX_OK);
112}
113
114uptr GetPageSize() { return _zx_system_get_page_size(); }
115
116uptr GetMmapGranularity() { return _zx_system_get_page_size(); }
117
118sanitizer_shadow_bounds_t ShadowBounds;
119
120void InitShadowBounds() { ShadowBounds = __sanitizer_shadow_bounds(); }
121
122uptr GetMaxUserVirtualAddress() {
123  InitShadowBounds();
124  return ShadowBounds.memory_limit - 1;
125}
126
127uptr GetMaxVirtualAddress() { return GetMaxUserVirtualAddress(); }
128
129bool ErrorIsOOM(error_t err) { return err == ZX_ERR_NO_MEMORY; }
130
131// For any sanitizer internal that needs to map something which can be unmapped
132// later, first attempt to map to a pre-allocated VMAR. This helps reduce
133// fragmentation from many small anonymous mmap calls. A good value for this
134// VMAR size would be the total size of your typical sanitizer internal objects
135// allocated in an "average" process lifetime. Examples of this include:
136// FakeStack, LowLevelAllocator mappings, TwoLevelMap, InternalMmapVector,
137// StackStore, CreateAsanThread, etc.
138//
139// This is roughly equal to the total sum of sanitizer internal mappings for a
140// large test case.
141constexpr size_t kSanitizerHeapVmarSize = 13ULL << 20;
142static zx_handle_t gSanitizerHeapVmar = ZX_HANDLE_INVALID;
143
144static zx_status_t GetSanitizerHeapVmar(zx_handle_t *vmar) {
145  zx_status_t status = ZX_OK;
146  if (gSanitizerHeapVmar == ZX_HANDLE_INVALID) {
147    CHECK_EQ(kSanitizerHeapVmarSize % GetPageSizeCached(), 0);
148    uintptr_t base;
149    status = _zx_vmar_allocate(
150        _zx_vmar_root_self(),
151        ZX_VM_CAN_MAP_READ | ZX_VM_CAN_MAP_WRITE | ZX_VM_CAN_MAP_SPECIFIC, 0,
152        kSanitizerHeapVmarSize, &gSanitizerHeapVmar, &base);
153  }
154  *vmar = gSanitizerHeapVmar;
155  if (status == ZX_OK)
156    CHECK_NE(gSanitizerHeapVmar, ZX_HANDLE_INVALID);
157  return status;
158}
159
160static zx_status_t TryVmoMapSanitizerVmar(zx_vm_option_t options,
161                                          size_t vmar_offset, zx_handle_t vmo,
162                                          size_t size, uintptr_t *addr,
163                                          zx_handle_t *vmar_used = nullptr) {
164  zx_handle_t vmar;
165  zx_status_t status = GetSanitizerHeapVmar(&vmar);
166  if (status != ZX_OK)
167    return status;
168
169  status = _zx_vmar_map(gSanitizerHeapVmar, options, vmar_offset, vmo,
170                        /*vmo_offset=*/0, size, addr);
171  if (vmar_used)
172    *vmar_used = gSanitizerHeapVmar;
173  if (status == ZX_ERR_NO_RESOURCES || status == ZX_ERR_INVALID_ARGS) {
174    // This means there's no space in the heap VMAR, so fallback to the root
175    // VMAR.
176    status = _zx_vmar_map(_zx_vmar_root_self(), options, vmar_offset, vmo,
177                          /*vmo_offset=*/0, size, addr);
178    if (vmar_used)
179      *vmar_used = _zx_vmar_root_self();
180  }
181
182  return status;
183}
184
185static void *DoAnonymousMmapOrDie(uptr size, const char *mem_type,
186                                  bool raw_report, bool die_for_nomem) {
187  size = RoundUpTo(size, GetPageSize());
188
189  zx_handle_t vmo;
190  zx_status_t status = _zx_vmo_create(size, 0, &vmo);
191  if (status != ZX_OK) {
192    if (status != ZX_ERR_NO_MEMORY || die_for_nomem)
193      ReportMmapFailureAndDie(size, mem_type, "zx_vmo_create", status,
194                              raw_report);
195    return nullptr;
196  }
197  _zx_object_set_property(vmo, ZX_PROP_NAME, mem_type,
198                          internal_strlen(mem_type));
199
200  uintptr_t addr;
201  status = TryVmoMapSanitizerVmar(ZX_VM_PERM_READ | ZX_VM_PERM_WRITE,
202                                  /*vmar_offset=*/0, vmo, size, &addr);
203  _zx_handle_close(vmo);
204
205  if (status != ZX_OK) {
206    if (status != ZX_ERR_NO_MEMORY || die_for_nomem)
207      ReportMmapFailureAndDie(size, mem_type, "zx_vmar_map", status,
208                              raw_report);
209    return nullptr;
210  }
211
212  IncreaseTotalMmap(size);
213
214  return reinterpret_cast<void *>(addr);
215}
216
217void *MmapOrDie(uptr size, const char *mem_type, bool raw_report) {
218  return DoAnonymousMmapOrDie(size, mem_type, raw_report, true);
219}
220
221void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
222  return MmapOrDie(size, mem_type);
223}
224
225void *MmapOrDieOnFatalError(uptr size, const char *mem_type) {
226  return DoAnonymousMmapOrDie(size, mem_type, false, false);
227}
228
229uptr ReservedAddressRange::Init(uptr init_size, const char *name,
230                                uptr fixed_addr) {
231  init_size = RoundUpTo(init_size, GetPageSize());
232  DCHECK_EQ(os_handle_, ZX_HANDLE_INVALID);
233  uintptr_t base;
234  zx_handle_t vmar;
235  zx_status_t status = _zx_vmar_allocate(
236      _zx_vmar_root_self(),
237      ZX_VM_CAN_MAP_READ | ZX_VM_CAN_MAP_WRITE | ZX_VM_CAN_MAP_SPECIFIC, 0,
238      init_size, &vmar, &base);
239  if (status != ZX_OK)
240    ReportMmapFailureAndDie(init_size, name, "zx_vmar_allocate", status);
241  base_ = reinterpret_cast<void *>(base);
242  size_ = init_size;
243  name_ = name;
244  os_handle_ = vmar;
245
246  return reinterpret_cast<uptr>(base_);
247}
248
249static uptr DoMmapFixedOrDie(zx_handle_t vmar, uptr fixed_addr, uptr map_size,
250                             void *base, const char *name, bool die_for_nomem) {
251  uptr offset = fixed_addr - reinterpret_cast<uptr>(base);
252  map_size = RoundUpTo(map_size, GetPageSize());
253  zx_handle_t vmo;
254  zx_status_t status = _zx_vmo_create(map_size, 0, &vmo);
255  if (status != ZX_OK) {
256    if (status != ZX_ERR_NO_MEMORY || die_for_nomem)
257      ReportMmapFailureAndDie(map_size, name, "zx_vmo_create", status);
258    return 0;
259  }
260  _zx_object_set_property(vmo, ZX_PROP_NAME, name, internal_strlen(name));
261  DCHECK_GE(base + size_, map_size + offset);
262  uintptr_t addr;
263
264  status =
265      _zx_vmar_map(vmar, ZX_VM_PERM_READ | ZX_VM_PERM_WRITE | ZX_VM_SPECIFIC,
266                   offset, vmo, 0, map_size, &addr);
267  _zx_handle_close(vmo);
268  if (status != ZX_OK) {
269    if (status != ZX_ERR_NO_MEMORY || die_for_nomem) {
270      ReportMmapFailureAndDie(map_size, name, "zx_vmar_map", status);
271    }
272    return 0;
273  }
274  IncreaseTotalMmap(map_size);
275  return addr;
276}
277
278uptr ReservedAddressRange::Map(uptr fixed_addr, uptr map_size,
279                               const char *name) {
280  return DoMmapFixedOrDie(os_handle_, fixed_addr, map_size, base_,
281                          name ? name : name_, false);
282}
283
284uptr ReservedAddressRange::MapOrDie(uptr fixed_addr, uptr map_size,
285                                    const char *name) {
286  return DoMmapFixedOrDie(os_handle_, fixed_addr, map_size, base_,
287                          name ? name : name_, true);
288}
289
290void UnmapOrDieVmar(void *addr, uptr size, zx_handle_t target_vmar,
291                    bool raw_report) {
292  if (!addr || !size)
293    return;
294  size = RoundUpTo(size, GetPageSize());
295
296  zx_status_t status =
297      _zx_vmar_unmap(target_vmar, reinterpret_cast<uintptr_t>(addr), size);
298  if (status == ZX_ERR_INVALID_ARGS && target_vmar == gSanitizerHeapVmar) {
299    // If there wasn't any space in the heap vmar, the fallback was the root
300    // vmar.
301    status = _zx_vmar_unmap(_zx_vmar_root_self(),
302                            reinterpret_cast<uintptr_t>(addr), size);
303  }
304  if (status != ZX_OK)
305    ReportMunmapFailureAndDie(addr, size, status, raw_report);
306
307  DecreaseTotalMmap(size);
308}
309
310void ReservedAddressRange::Unmap(uptr addr, uptr size) {
311  CHECK_LE(size, size_);
312  const zx_handle_t vmar = static_cast<zx_handle_t>(os_handle_);
313  if (addr == reinterpret_cast<uptr>(base_)) {
314    if (size == size_) {
315      // Destroying the vmar effectively unmaps the whole mapping.
316      _zx_vmar_destroy(vmar);
317      _zx_handle_close(vmar);
318      os_handle_ = static_cast<uptr>(ZX_HANDLE_INVALID);
319      DecreaseTotalMmap(size);
320      return;
321    }
322  } else {
323    CHECK_EQ(addr + size, reinterpret_cast<uptr>(base_) + size_);
324  }
325  // Partial unmapping does not affect the fact that the initial range is still
326  // reserved, and the resulting unmapped memory can't be reused.
327  UnmapOrDieVmar(reinterpret_cast<void *>(addr), size, vmar,
328                 /*raw_report=*/false);
329}
330
331// This should never be called.
332void *MmapFixedNoAccess(uptr fixed_addr, uptr size, const char *name) {
333  UNIMPLEMENTED();
334}
335
336bool MprotectNoAccess(uptr addr, uptr size) {
337  return _zx_vmar_protect(_zx_vmar_root_self(), 0, addr, size) == ZX_OK;
338}
339
340bool MprotectReadOnly(uptr addr, uptr size) {
341  return _zx_vmar_protect(_zx_vmar_root_self(), ZX_VM_PERM_READ, addr, size) ==
342         ZX_OK;
343}
344
345bool MprotectReadWrite(uptr addr, uptr size) {
346  return _zx_vmar_protect(_zx_vmar_root_self(),
347                          ZX_VM_PERM_READ | ZX_VM_PERM_WRITE, addr,
348                          size) == ZX_OK;
349}
350
351void *MmapAlignedOrDieOnFatalError(uptr size, uptr alignment,
352                                   const char *mem_type) {
353  CHECK_GE(size, GetPageSize());
354  CHECK(IsPowerOfTwo(size));
355  CHECK(IsPowerOfTwo(alignment));
356
357  zx_handle_t vmo;
358  zx_status_t status = _zx_vmo_create(size, 0, &vmo);
359  if (status != ZX_OK) {
360    if (status != ZX_ERR_NO_MEMORY)
361      ReportMmapFailureAndDie(size, mem_type, "zx_vmo_create", status, false);
362    return nullptr;
363  }
364  _zx_object_set_property(vmo, ZX_PROP_NAME, mem_type,
365                          internal_strlen(mem_type));
366
367  // Map a larger size to get a chunk of address space big enough that
368  // it surely contains an aligned region of the requested size.  Then
369  // overwrite the aligned middle portion with a mapping from the
370  // beginning of the VMO, and unmap the excess before and after.
371  size_t map_size = size + alignment;
372  uintptr_t addr;
373  zx_handle_t vmar_used;
374  status = TryVmoMapSanitizerVmar(ZX_VM_PERM_READ | ZX_VM_PERM_WRITE,
375                                  /*vmar_offset=*/0, vmo, map_size, &addr,
376                                  &vmar_used);
377  if (status == ZX_OK) {
378    uintptr_t map_addr = addr;
379    uintptr_t map_end = map_addr + map_size;
380    addr = RoundUpTo(map_addr, alignment);
381    uintptr_t end = addr + size;
382    if (addr != map_addr) {
383      zx_info_vmar_t info;
384      status = _zx_object_get_info(vmar_used, ZX_INFO_VMAR, &info, sizeof(info),
385                                   NULL, NULL);
386      if (status == ZX_OK) {
387        uintptr_t new_addr;
388        status = _zx_vmar_map(
389            vmar_used,
390            ZX_VM_PERM_READ | ZX_VM_PERM_WRITE | ZX_VM_SPECIFIC_OVERWRITE,
391            addr - info.base, vmo, 0, size, &new_addr);
392        if (status == ZX_OK)
393          CHECK_EQ(new_addr, addr);
394      }
395    }
396    if (status == ZX_OK && addr != map_addr)
397      status = _zx_vmar_unmap(vmar_used, map_addr, addr - map_addr);
398    if (status == ZX_OK && end != map_end)
399      status = _zx_vmar_unmap(vmar_used, end, map_end - end);
400  }
401  _zx_handle_close(vmo);
402
403  if (status != ZX_OK) {
404    if (status != ZX_ERR_NO_MEMORY)
405      ReportMmapFailureAndDie(size, mem_type, "zx_vmar_map", status, false);
406    return nullptr;
407  }
408
409  IncreaseTotalMmap(size);
410
411  return reinterpret_cast<void *>(addr);
412}
413
414void UnmapOrDie(void *addr, uptr size, bool raw_report) {
415  UnmapOrDieVmar(addr, size, gSanitizerHeapVmar, raw_report);
416}
417
418void ReleaseMemoryPagesToOS(uptr beg, uptr end) {
419  uptr beg_aligned = RoundUpTo(beg, GetPageSize());
420  uptr end_aligned = RoundDownTo(end, GetPageSize());
421  if (beg_aligned < end_aligned) {
422    zx_handle_t root_vmar = _zx_vmar_root_self();
423    CHECK_NE(root_vmar, ZX_HANDLE_INVALID);
424    zx_status_t status =
425        _zx_vmar_op_range(root_vmar, ZX_VMAR_OP_DECOMMIT, beg_aligned,
426                          end_aligned - beg_aligned, nullptr, 0);
427    CHECK_EQ(status, ZX_OK);
428  }
429}
430
431void DumpProcessMap() {
432  // TODO(mcgrathr): write it
433  return;
434}
435
436bool IsAccessibleMemoryRange(uptr beg, uptr size) {
437  // TODO(mcgrathr): Figure out a better way.
438  zx_handle_t vmo;
439  zx_status_t status = _zx_vmo_create(size, 0, &vmo);
440  if (status == ZX_OK) {
441    status = _zx_vmo_write(vmo, reinterpret_cast<const void *>(beg), 0, size);
442    _zx_handle_close(vmo);
443  }
444  return status == ZX_OK;
445}
446
447bool TryMemCpy(void *dest, const void *src, uptr n) {
448  // TODO: implement.
449  return false;
450}
451
452// FIXME implement on this platform.
453void GetMemoryProfile(fill_profile_f cb, uptr *stats) {}
454
455bool ReadFileToBuffer(const char *file_name, char **buff, uptr *buff_size,
456                      uptr *read_len, uptr max_len, error_t *errno_p) {
457  *errno_p = ZX_ERR_NOT_SUPPORTED;
458  return false;
459}
460
461void RawWrite(const char *buffer) {
462  constexpr size_t size = 128;
463  static _Thread_local char line[size];
464  static _Thread_local size_t lastLineEnd = 0;
465  static _Thread_local size_t cur = 0;
466
467  while (*buffer) {
468    if (cur >= size) {
469      if (lastLineEnd == 0)
470        lastLineEnd = size;
471      __sanitizer_log_write(line, lastLineEnd);
472      internal_memmove(line, line + lastLineEnd, cur - lastLineEnd);
473      cur = cur - lastLineEnd;
474      lastLineEnd = 0;
475    }
476    if (*buffer == '\n')
477      lastLineEnd = cur + 1;
478    line[cur++] = *buffer++;
479  }
480  // Flush all complete lines before returning.
481  if (lastLineEnd != 0) {
482    __sanitizer_log_write(line, lastLineEnd);
483    internal_memmove(line, line + lastLineEnd, cur - lastLineEnd);
484    cur = cur - lastLineEnd;
485    lastLineEnd = 0;
486  }
487}
488
489void CatastrophicErrorWrite(const char *buffer, uptr length) {
490  __sanitizer_log_write(buffer, length);
491}
492
493char **StoredArgv;
494char **StoredEnviron;
495
496char **GetArgv() { return StoredArgv; }
497char **GetEnviron() { return StoredEnviron; }
498
499const char *GetEnv(const char *name) {
500  if (StoredEnviron) {
501    uptr NameLen = internal_strlen(name);
502    for (char **Env = StoredEnviron; *Env != 0; Env++) {
503      if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
504        return (*Env) + NameLen + 1;
505    }
506  }
507  return nullptr;
508}
509
510uptr ReadBinaryName(/*out*/ char *buf, uptr buf_len) {
511  const char *argv0 = "<UNKNOWN>";
512  if (StoredArgv && StoredArgv[0]) {
513    argv0 = StoredArgv[0];
514  }
515  internal_strncpy(buf, argv0, buf_len);
516  return internal_strlen(buf);
517}
518
519uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
520  return ReadBinaryName(buf, buf_len);
521}
522
523uptr MainThreadStackBase, MainThreadStackSize;
524
525bool GetRandom(void *buffer, uptr length, bool blocking) {
526  _zx_cprng_draw(buffer, length);
527  return true;
528}
529
530u32 GetNumberOfCPUs() { return zx_system_get_num_cpus(); }
531
532uptr GetRSS() { UNIMPLEMENTED(); }
533
534void *internal_start_thread(void *(*func)(void *arg), void *arg) { return 0; }
535void internal_join_thread(void *th) {}
536
537void InitializePlatformCommonFlags(CommonFlags *cf) {}
538
539}  // namespace __sanitizer
540
541using namespace __sanitizer;
542
543extern "C" {
544void __sanitizer_startup_hook(int argc, char **argv, char **envp,
545                              void *stack_base, size_t stack_size) {
546  __sanitizer::StoredArgv = argv;
547  __sanitizer::StoredEnviron = envp;
548  __sanitizer::MainThreadStackBase = reinterpret_cast<uintptr_t>(stack_base);
549  __sanitizer::MainThreadStackSize = stack_size;
550
551  EarlySanitizerInit();
552}
553
554void __sanitizer_set_report_path(const char *path) {
555  // Handle the initialization code in each sanitizer, but no other calls.
556  // This setting is never consulted on Fuchsia.
557  DCHECK_EQ(path, common_flags()->log_path);
558}
559
560void __sanitizer_set_report_fd(void *fd) {
561  UNREACHABLE("not available on Fuchsia");
562}
563
564const char *__sanitizer_get_report_path() {
565  UNREACHABLE("not available on Fuchsia");
566}
567}  // extern "C"
568
569#endif  // SANITIZER_FUCHSIA