libsanitizer/sanitizer_common/sanitizer_mac.cc

   1 //===-- sanitizer_mac.cc --------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is shared between various sanitizers' runtime libraries and
   9 // implements OSX-specific functions.
  10 //===----------------------------------------------------------------------===//
  11
  12 #include "sanitizer_platform.h"
  13 #if SANITIZER_MAC
  14 #include "sanitizer_mac.h"
  15
  16 // Use 64-bit inodes in file operations. ASan does not support OS X 10.5, so
  17 // the clients will most certainly use 64-bit ones as well.
  18 #ifndef _DARWIN_USE_64_BIT_INODE
  19 #define _DARWIN_USE_64_BIT_INODE 1
  20 #endif
  21 #include <stdio.h>
  22
  23 #include "sanitizer_common.h"
  24 #include "sanitizer_file.h"
  25 #include "sanitizer_flags.h"
  26 #include "sanitizer_internal_defs.h"
  27 #include "sanitizer_libc.h"
  28 #include "sanitizer_placement_new.h"
  29 #include "sanitizer_platform_limits_posix.h"
  30 #include "sanitizer_procmaps.h"
  31
  32 #if !SANITIZER_IOS
  33 #include <crt_externs.h>  // for _NSGetEnviron
  34 #else
  35 extern char **environ;
  36 #endif
  37
  38 #if defined(__has_include) && __has_include(<os/trace.h>) && defined(__BLOCKS__)
  39 #define SANITIZER_OS_TRACE 1
  40 #include <os/trace.h>
  41 #else
  42 #define SANITIZER_OS_TRACE 0
  43 #endif
  44
  45 #if !SANITIZER_IOS
  46 #include <crt_externs.h>  // for _NSGetArgv and _NSGetEnviron
  47 #else
  48 extern "C" {
  49   extern char ***_NSGetArgv(void);
  50 }
  51 #endif
  52
  53 #include <asl.h>
  54 #include <dlfcn.h>  // for dladdr()
  55 #include <errno.h>
  56 #include <fcntl.h>
  57 #include <libkern/OSAtomic.h>
  58 #include <mach-o/dyld.h>
  59 #include <mach/mach.h>
  60 #include <mach/vm_statistics.h>
  61 #include <pthread.h>
  62 #include <sched.h>
  63 #include <signal.h>
  64 #include <stdlib.h>
  65 #include <sys/mman.h>
  66 #include <sys/resource.h>
  67 #include <sys/stat.h>
  68 #include <sys/sysctl.h>
  69 #include <sys/types.h>
  70 #include <sys/wait.h>
  71 #include <unistd.h>
  72 #include <util.h>
  73
  74 // From <crt_externs.h>, but we don't have that file on iOS.
  75 extern "C" {
  76   extern char ***_NSGetArgv(void);
  77   extern char ***_NSGetEnviron(void);
  78 }
  79
  80 // From <mach/mach_vm.h>, but we don't have that file on iOS.
  81 extern "C" {
  82   extern kern_return_t mach_vm_region_recurse(
  83     vm_map_t target_task,
  84     mach_vm_address_t *address,
  85     mach_vm_size_t *size,
  86     natural_t *nesting_depth,
  87     vm_region_recurse_info_t info,
  88     mach_msg_type_number_t *infoCnt);
  89 }
  90
  91 namespace __sanitizer {
  92
  93 #include "sanitizer_syscall_generic.inc"
  94
  95 // Direct syscalls, don't call libmalloc hooks (but not available on 10.6).
  96 extern "C" void *__mmap(void *addr, size_t len, int prot, int flags, int fildes,
  97                         off_t off) SANITIZER_WEAK_ATTRIBUTE;
  98 extern "C" int __munmap(void *, size_t) SANITIZER_WEAK_ATTRIBUTE;
  99
 100 // ---------------------- sanitizer_libc.h
 101 uptr internal_mmap(void *addr, size_t length, int prot, int flags,
 102                    int fd, u64 offset) {
 103   if (fd == -1) fd = VM_MAKE_TAG(VM_MEMORY_ANALYSIS_TOOL);
 104   if (&__mmap) return (uptr)__mmap(addr, length, prot, flags, fd, offset);
 105   return (uptr)mmap(addr, length, prot, flags, fd, offset);
 106 }
 107
 108 uptr internal_munmap(void *addr, uptr length) {
 109   if (&__munmap) return __munmap(addr, length);
 110   return munmap(addr, length);
 111 }
 112
 113 int internal_mprotect(void *addr, uptr length, int prot) {
 114   return mprotect(addr, length, prot);
 115 }
 116
 117 uptr internal_close(fd_t fd) {
 118   return close(fd);
 119 }
 120
 121 uptr internal_open(const char *filename, int flags) {
 122   return open(filename, flags);
 123 }
 124
 125 uptr internal_open(const char *filename, int flags, u32 mode) {
 126   return open(filename, flags, mode);
 127 }
 128
 129 uptr internal_read(fd_t fd, void *buf, uptr count) {
 130   return read(fd, buf, count);
 131 }
 132
 133 uptr internal_write(fd_t fd, const void *buf, uptr count) {
 134   return write(fd, buf, count);
 135 }
 136
 137 uptr internal_stat(const char *path, void *buf) {
 138   return stat(path, (struct stat *)buf);
 139 }
 140
 141 uptr internal_lstat(const char *path, void *buf) {
 142   return lstat(path, (struct stat *)buf);
 143 }
 144
 145 uptr internal_fstat(fd_t fd, void *buf) {
 146   return fstat(fd, (struct stat *)buf);
 147 }
 148
 149 uptr internal_filesize(fd_t fd) {
 150   struct stat st;
 151   if (internal_fstat(fd, &st))
 152     return -1;
 153   return (uptr)st.st_size;
 154 }
 155
 156 uptr internal_dup2(int oldfd, int newfd) {
 157   return dup2(oldfd, newfd);
 158 }
 159
 160 uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
 161   return readlink(path, buf, bufsize);
 162 }
 163
 164 uptr internal_unlink(const char *path) {
 165   return unlink(path);
 166 }
 167
 168 uptr internal_sched_yield() {
 169   return sched_yield();
 170 }
 171
 172 void internal__exit(int exitcode) {
 173   _exit(exitcode);
 174 }
 175
 176 unsigned int internal_sleep(unsigned int seconds) {
 177   return sleep(seconds);
 178 }
 179
 180 uptr internal_getpid() {
 181   return getpid();
 182 }
 183
 184 int internal_sigaction(int signum, const void *act, void *oldact) {
 185   return sigaction(signum,
 186                    (struct sigaction *)act, (struct sigaction *)oldact);
 187 }
 188
 189 void internal_sigfillset(__sanitizer_sigset_t *set) { sigfillset(set); }
 190
 191 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
 192                           __sanitizer_sigset_t *oldset) {
 193   // Don't use sigprocmask here, because it affects all threads.
 194   return pthread_sigmask(how, set, oldset);
 195 }
 196
 197 // Doesn't call pthread_atfork() handlers (but not available on 10.6).
 198 extern "C" pid_t __fork(void) SANITIZER_WEAK_ATTRIBUTE;
 199
 200 int internal_fork() {
 201   if (&__fork)
 202     return __fork();
 203   return fork();
 204 }
 205
 206 int internal_forkpty(int *amaster) {
 207   int master, slave;
 208   if (openpty(&master, &slave, nullptr, nullptr, nullptr) == -1) return -1;
 209   int pid = internal_fork();
 210   if (pid == -1) {
 211     close(master);
 212     close(slave);
 213     return -1;
 214   }
 215   if (pid == 0) {
 216     close(master);
 217     if (login_tty(slave) != 0) {
 218       // We already forked, there's not much we can do.  Let's quit.
 219       Report("login_tty failed (errno %d)\n", errno);
 220       internal__exit(1);
 221     }
 222   } else {
 223     *amaster = master;
 224     close(slave);
 225   }
 226   return pid;
 227 }
 228
 229 uptr internal_rename(const char *oldpath, const char *newpath) {
 230   return rename(oldpath, newpath);
 231 }
 232
 233 uptr internal_ftruncate(fd_t fd, uptr size) {
 234   return ftruncate(fd, size);
 235 }
 236
 237 uptr internal_execve(const char *filename, char *const argv[],
 238                      char *const envp[]) {
 239   return execve(filename, argv, envp);
 240 }
 241
 242 uptr internal_waitpid(int pid, int *status, int options) {
 243   return waitpid(pid, status, options);
 244 }
 245
 246 // ----------------- sanitizer_common.h
 247 bool FileExists(const char *filename) {
 248   struct stat st;
 249   if (stat(filename, &st))
 250     return false;
 251   // Sanity check: filename is a regular file.
 252   return S_ISREG(st.st_mode);
 253 }
 254
 255 tid_t GetTid() {
 256   tid_t tid;
 257   pthread_threadid_np(nullptr, &tid);
 258   return tid;
 259 }
 260
 261 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
 262                                 uptr *stack_bottom) {
 263   CHECK(stack_top);
 264   CHECK(stack_bottom);
 265   uptr stacksize = pthread_get_stacksize_np(pthread_self());
 266   // pthread_get_stacksize_np() returns an incorrect stack size for the main
 267   // thread on Mavericks. See
 268   // https://github.com/google/sanitizers/issues/261
 269   if ((GetMacosVersion() >= MACOS_VERSION_MAVERICKS) && at_initialization &&
 270       stacksize == (1 << 19))  {
 271     struct rlimit rl;
 272     CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0);
 273     // Most often rl.rlim_cur will be the desired 8M.
 274     if (rl.rlim_cur < kMaxThreadStackSize) {
 275       stacksize = rl.rlim_cur;
 276     } else {
 277       stacksize = kMaxThreadStackSize;
 278     }
 279   }
 280   void *stackaddr = pthread_get_stackaddr_np(pthread_self());
 281   *stack_top = (uptr)stackaddr;
 282   *stack_bottom = *stack_top - stacksize;
 283 }
 284
 285 char **GetEnviron() {
 286 #if !SANITIZER_IOS
 287   char ***env_ptr = _NSGetEnviron();
 288   if (!env_ptr) {
 289     Report("_NSGetEnviron() returned NULL. Please make sure __asan_init() is "
 290            "called after libSystem_initializer().\n");
 291     CHECK(env_ptr);
 292   }
 293   char **environ = *env_ptr;
 294 #endif
 295   CHECK(environ);
 296   return environ;
 297 }
 298
 299 const char *GetEnv(const char *name) {
 300   char **env = GetEnviron();
 301   uptr name_len = internal_strlen(name);
 302   while (*env != 0) {
 303     uptr len = internal_strlen(*env);
 304     if (len > name_len) {
 305       const char *p = *env;
 306       if (!internal_memcmp(p, name, name_len) &&
 307           p[name_len] == '=') {  // Match.
 308         return *env + name_len + 1;  // String starting after =.
 309       }
 310     }
 311     env++;
 312   }
 313   return 0;
 314 }
 315
 316 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
 317   CHECK_LE(kMaxPathLength, buf_len);
 318
 319   // On OS X the executable path is saved to the stack by dyld. Reading it
 320   // from there is much faster than calling dladdr, especially for large
 321   // binaries with symbols.
 322   InternalScopedString exe_path(kMaxPathLength);
 323   uint32_t size = exe_path.size();
 324   if (_NSGetExecutablePath(exe_path.data(), &size) == 0 &&
 325       realpath(exe_path.data(), buf) != 0) {
 326     return internal_strlen(buf);
 327   }
 328   return 0;
 329 }
 330
 331 uptr ReadLongProcessName(/*out*/char *buf, uptr buf_len) {
 332   return ReadBinaryName(buf, buf_len);
 333 }
 334
 335 void ReExec() {
 336   UNIMPLEMENTED();
 337 }
 338
 339 uptr GetPageSize() {
 340   return sysconf(_SC_PAGESIZE);
 341 }
 342
 343 BlockingMutex::BlockingMutex() {
 344   internal_memset(this, 0, sizeof(*this));
 345 }
 346
 347 void BlockingMutex::Lock() {
 348   CHECK(sizeof(OSSpinLock) <= sizeof(opaque_storage_));
 349   CHECK_EQ(OS_SPINLOCK_INIT, 0);
 350   CHECK_EQ(owner_, 0);
 351   OSSpinLockLock((OSSpinLock*)&opaque_storage_);
 352 }
 353
 354 void BlockingMutex::Unlock() {
 355   OSSpinLockUnlock((OSSpinLock*)&opaque_storage_);
 356 }
 357
 358 void BlockingMutex::CheckLocked() {
 359   CHECK_NE(*(OSSpinLock*)&opaque_storage_, 0);
 360 }
 361
 362 u64 NanoTime() {
 363   return 0;
 364 }
 365
 366 uptr GetTlsSize() {
 367   return 0;
 368 }
 369
 370 void InitTlsSize() {
 371 }
 372
 373 uptr TlsBaseAddr() {
 374   uptr segbase = 0;
 375 #if defined(__x86_64__)
 376   asm("movq %%gs:0,%0" : "=r"(segbase));
 377 #elif defined(__i386__)
 378   asm("movl %%gs:0,%0" : "=r"(segbase));
 379 #endif
 380   return segbase;
 381 }
 382
 383 // The size of the tls on darwin does not appear to be well documented,
 384 // however the vm memory map suggests that it is 1024 uptrs in size,
 385 // with a size of 0x2000 bytes on x86_64 and 0x1000 bytes on i386.
 386 uptr TlsSize() {
 387 #if defined(__x86_64__) || defined(__i386__)
 388   return 1024 * sizeof(uptr);
 389 #else
 390   return 0;
 391 #endif
 392 }
 393
 394 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
 395                           uptr *tls_addr, uptr *tls_size) {
 396 #if !SANITIZER_GO
 397   uptr stack_top, stack_bottom;
 398   GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
 399   *stk_addr = stack_bottom;
 400   *stk_size = stack_top - stack_bottom;
 401   *tls_addr = TlsBaseAddr();
 402   *tls_size = TlsSize();
 403 #else
 404   *stk_addr = 0;
 405   *stk_size = 0;
 406   *tls_addr = 0;
 407   *tls_size = 0;
 408 #endif
 409 }
 410
 411 void ListOfModules::init() {
 412   clearOrInit();
 413   MemoryMappingLayout memory_mapping(false);
 414   memory_mapping.DumpListOfModules(&modules_);
 415 }
 416
 417 void ListOfModules::fallbackInit() { clear(); }
 418
 419 static HandleSignalMode GetHandleSignalModeImpl(int signum) {
 420   switch (signum) {
 421     case SIGABRT:
 422       return common_flags()->handle_abort;
 423     case SIGILL:
 424       return common_flags()->handle_sigill;
 425     case SIGFPE:
 426       return common_flags()->handle_sigfpe;
 427     case SIGSEGV:
 428       return common_flags()->handle_segv;
 429     case SIGBUS:
 430       return common_flags()->handle_sigbus;
 431   }
 432   return kHandleSignalNo;
 433 }
 434
 435 HandleSignalMode GetHandleSignalMode(int signum) {
 436   // Handling fatal signals on watchOS and tvOS devices is disallowed.
 437   if ((SANITIZER_WATCHOS || SANITIZER_TVOS) && !(SANITIZER_IOSSIM))
 438     return kHandleSignalNo;
 439   HandleSignalMode result = GetHandleSignalModeImpl(signum);
 440   if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler)
 441     return kHandleSignalExclusive;
 442   return result;
 443 }
 444
 445 MacosVersion cached_macos_version = MACOS_VERSION_UNINITIALIZED;
 446
 447 MacosVersion GetMacosVersionInternal() {
 448   int mib[2] = { CTL_KERN, KERN_OSRELEASE };
 449   char version[100];
 450   uptr len = 0, maxlen = sizeof(version) / sizeof(version[0]);
 451   for (uptr i = 0; i < maxlen; i++) version[i] = '\0';
 452   // Get the version length.
 453   CHECK_NE(sysctl(mib, 2, 0, &len, 0, 0), -1);
 454   CHECK_LT(len, maxlen);
 455   CHECK_NE(sysctl(mib, 2, version, &len, 0, 0), -1);
 456   switch (version[0]) {
 457     case '9': return MACOS_VERSION_LEOPARD;
 458     case '1': {
 459       switch (version[1]) {
 460         case '0': return MACOS_VERSION_SNOW_LEOPARD;
 461         case '1': return MACOS_VERSION_LION;
 462         case '2': return MACOS_VERSION_MOUNTAIN_LION;
 463         case '3': return MACOS_VERSION_MAVERICKS;
 464         case '4': return MACOS_VERSION_YOSEMITE;
 465         default:
 466           if (IsDigit(version[1]))
 467             return MACOS_VERSION_UNKNOWN_NEWER;
 468           else
 469             return MACOS_VERSION_UNKNOWN;
 470       }
 471     }
 472     default: return MACOS_VERSION_UNKNOWN;
 473   }
 474 }
 475
 476 MacosVersion GetMacosVersion() {
 477   atomic_uint32_t *cache =
 478       reinterpret_cast<atomic_uint32_t*>(&cached_macos_version);
 479   MacosVersion result =
 480       static_cast<MacosVersion>(atomic_load(cache, memory_order_acquire));
 481   if (result == MACOS_VERSION_UNINITIALIZED) {
 482     result = GetMacosVersionInternal();
 483     atomic_store(cache, result, memory_order_release);
 484   }
 485   return result;
 486 }
 487
 488 bool PlatformHasDifferentMemcpyAndMemmove() {
 489   // On OS X 10.7 memcpy() and memmove() are both resolved
 490   // into memmove$VARIANT$sse42.
 491   // See also https://github.com/google/sanitizers/issues/34.
 492   // TODO(glider): need to check dynamically that memcpy() and memmove() are
 493   // actually the same function.
 494   return GetMacosVersion() == MACOS_VERSION_SNOW_LEOPARD;
 495 }
 496
 497 uptr GetRSS() {
 498   struct task_basic_info info;
 499   unsigned count = TASK_BASIC_INFO_COUNT;
 500   kern_return_t result =
 501       task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)&info, &count);
 502   if (UNLIKELY(result != KERN_SUCCESS)) {
 503     Report("Cannot get task info. Error: %d\n", result);
 504     Die();
 505   }
 506   return info.resident_size;
 507 }
 508
 509 void *internal_start_thread(void(*func)(void *arg), void *arg) {
 510   // Start the thread with signals blocked, otherwise it can steal user signals.
 511   __sanitizer_sigset_t set, old;
 512   internal_sigfillset(&set);
 513   internal_sigprocmask(SIG_SETMASK, &set, &old);
 514   pthread_t th;
 515   pthread_create(&th, 0, (void*(*)(void *arg))func, arg);
 516   internal_sigprocmask(SIG_SETMASK, &old, 0);
 517   return th;
 518 }
 519
 520 void internal_join_thread(void *th) { pthread_join((pthread_t)th, 0); }
 521
 522 #if !SANITIZER_GO
 523 static BlockingMutex syslog_lock(LINKER_INITIALIZED);
 524 #endif
 525
 526 void WriteOneLineToSyslog(const char *s) {
 527 #if !SANITIZER_GO
 528   syslog_lock.CheckLocked();
 529   asl_log(nullptr, nullptr, ASL_LEVEL_ERR, "%s", s);
 530 #endif
 531 }
 532
 533 void LogMessageOnPrintf(const char *str) {
 534   // Log all printf output to CrashLog.
 535   if (common_flags()->abort_on_error)
 536     CRAppendCrashLogMessage(str);
 537 }
 538
 539 void LogFullErrorReport(const char *buffer) {
 540 #if !SANITIZER_GO
 541   // Log with os_trace. This will make it into the crash log.
 542 #if SANITIZER_OS_TRACE
 543   if (GetMacosVersion() >= MACOS_VERSION_YOSEMITE) {
 544     // os_trace requires the message (format parameter) to be a string literal.
 545     if (internal_strncmp(SanitizerToolName, "AddressSanitizer",
 546                          sizeof("AddressSanitizer") - 1) == 0)
 547       os_trace("Address Sanitizer reported a failure.");
 548     else if (internal_strncmp(SanitizerToolName, "UndefinedBehaviorSanitizer",
 549                               sizeof("UndefinedBehaviorSanitizer") - 1) == 0)
 550       os_trace("Undefined Behavior Sanitizer reported a failure.");
 551     else if (internal_strncmp(SanitizerToolName, "ThreadSanitizer",
 552                               sizeof("ThreadSanitizer") - 1) == 0)
 553       os_trace("Thread Sanitizer reported a failure.");
 554     else
 555       os_trace("Sanitizer tool reported a failure.");
 556
 557     if (common_flags()->log_to_syslog)
 558       os_trace("Consult syslog for more information.");
 559   }
 560 #endif
 561
 562   // Log to syslog.
 563   // The logging on OS X may call pthread_create so we need the threading
 564   // environment to be fully initialized. Also, this should never be called when
 565   // holding the thread registry lock since that may result in a deadlock. If
 566   // the reporting thread holds the thread registry mutex, and asl_log waits
 567   // for GCD to dispatch a new thread, the process will deadlock, because the
 568   // pthread_create wrapper needs to acquire the lock as well.
 569   BlockingMutexLock l(&syslog_lock);
 570   if (common_flags()->log_to_syslog)
 571     WriteToSyslog(buffer);
 572
 573   // The report is added to CrashLog as part of logging all of Printf output.
 574 #endif
 575 }
 576
 577 SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
 578 #if defined(__x86_64__) || defined(__i386__)
 579   ucontext_t *ucontext = static_cast<ucontext_t*>(context);
 580   return ucontext->uc_mcontext->__es.__err & 2 /*T_PF_WRITE*/ ? WRITE : READ;
 581 #else
 582   return UNKNOWN;
 583 #endif
 584 }
 585
 586 static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
 587   ucontext_t *ucontext = (ucontext_t*)context;
 588 # if defined(__aarch64__)
 589   *pc = ucontext->uc_mcontext->__ss.__pc;
 590 #   if defined(__IPHONE_8_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_8_0
 591   *bp = ucontext->uc_mcontext->__ss.__fp;
 592 #   else
 593   *bp = ucontext->uc_mcontext->__ss.__lr;
 594 #   endif
 595   *sp = ucontext->uc_mcontext->__ss.__sp;
 596 # elif defined(__x86_64__)
 597   *pc = ucontext->uc_mcontext->__ss.__rip;
 598   *bp = ucontext->uc_mcontext->__ss.__rbp;
 599   *sp = ucontext->uc_mcontext->__ss.__rsp;
 600 # elif defined(__arm__)
 601   *pc = ucontext->uc_mcontext->__ss.__pc;
 602   *bp = ucontext->uc_mcontext->__ss.__r[7];
 603   *sp = ucontext->uc_mcontext->__ss.__sp;
 604 # elif defined(__i386__)
 605   *pc = ucontext->uc_mcontext->__ss.__eip;
 606   *bp = ucontext->uc_mcontext->__ss.__ebp;
 607   *sp = ucontext->uc_mcontext->__ss.__esp;
 608 # else
 609 # error "Unknown architecture"
 610 # endif
 611 }
 612
 613 void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); }
 614
 615 #if !SANITIZER_GO
 616 static const char kDyldInsertLibraries[] = "DYLD_INSERT_LIBRARIES";
 617 LowLevelAllocator allocator_for_env;
 618
 619 // Change the value of the env var |name|, leaking the original value.
 620 // If |name_value| is NULL, the variable is deleted from the environment,
 621 // otherwise the corresponding "NAME=value" string is replaced with
 622 // |name_value|.
 623 void LeakyResetEnv(const char *name, const char *name_value) {
 624   char **env = GetEnviron();
 625   uptr name_len = internal_strlen(name);
 626   while (*env != 0) {
 627     uptr len = internal_strlen(*env);
 628     if (len > name_len) {
 629       const char *p = *env;
 630       if (!internal_memcmp(p, name, name_len) && p[name_len] == '=') {
 631         // Match.
 632         if (name_value) {
 633           // Replace the old value with the new one.
 634           *env = const_cast<char*>(name_value);
 635         } else {
 636           // Shift the subsequent pointers back.
 637           char **del = env;
 638           do {
 639             del[0] = del[1];
 640           } while (*del++);
 641         }
 642       }
 643     }
 644     env++;
 645   }
 646 }
 647
 648 SANITIZER_WEAK_CXX_DEFAULT_IMPL
 649 bool ReexecDisabled() {
 650   return false;
 651 }
 652
 653 extern "C" SANITIZER_WEAK_ATTRIBUTE double dyldVersionNumber;
 654 static const double kMinDyldVersionWithAutoInterposition = 360.0;
 655
 656 bool DyldNeedsEnvVariable() {
 657   // Although sanitizer support was added to LLVM on OS X 10.7+, GCC users
 658   // still may want use them on older systems. On older Darwin platforms, dyld
 659   // doesn't export dyldVersionNumber symbol and we simply return true.
 660   if (!&dyldVersionNumber) return true;
 661   // If running on OS X 10.11+ or iOS 9.0+, dyld will interpose even if
 662   // DYLD_INSERT_LIBRARIES is not set. However, checking OS version via
 663   // GetMacosVersion() doesn't work for the simulator. Let's instead check
 664   // `dyldVersionNumber`, which is exported by dyld, against a known version
 665   // number from the first OS release where this appeared.
 666   return dyldVersionNumber < kMinDyldVersionWithAutoInterposition;
 667 }
 668
 669 void MaybeReexec() {
 670   if (ReexecDisabled()) return;
 671
 672   // Make sure the dynamic runtime library is preloaded so that the
 673   // wrappers work. If it is not, set DYLD_INSERT_LIBRARIES and re-exec
 674   // ourselves.
 675   Dl_info info;
 676   RAW_CHECK(dladdr((void*)((uptr)&__sanitizer_report_error_summary), &info));
 677   char *dyld_insert_libraries =
 678       const_cast<char*>(GetEnv(kDyldInsertLibraries));
 679   uptr old_env_len = dyld_insert_libraries ?
 680       internal_strlen(dyld_insert_libraries) : 0;
 681   uptr fname_len = internal_strlen(info.dli_fname);
 682   const char *dylib_name = StripModuleName(info.dli_fname);
 683   uptr dylib_name_len = internal_strlen(dylib_name);
 684
 685   bool lib_is_in_env = dyld_insert_libraries &&
 686                        internal_strstr(dyld_insert_libraries, dylib_name);
 687   if (DyldNeedsEnvVariable() && !lib_is_in_env) {
 688     // DYLD_INSERT_LIBRARIES is not set or does not contain the runtime
 689     // library.
 690     InternalScopedString program_name(1024);
 691     uint32_t buf_size = program_name.size();
 692     _NSGetExecutablePath(program_name.data(), &buf_size);
 693     char *new_env = const_cast<char*>(info.dli_fname);
 694     if (dyld_insert_libraries) {
 695       // Append the runtime dylib name to the existing value of
 696       // DYLD_INSERT_LIBRARIES.
 697       new_env = (char*)allocator_for_env.Allocate(old_env_len + fname_len + 2);
 698       internal_strncpy(new_env, dyld_insert_libraries, old_env_len);
 699       new_env[old_env_len] = ':';
 700       // Copy fname_len and add a trailing zero.
 701       internal_strncpy(new_env + old_env_len + 1, info.dli_fname,
 702                        fname_len + 1);
 703       // Ok to use setenv() since the wrappers don't depend on the value of
 704       // asan_inited.
 705       setenv(kDyldInsertLibraries, new_env, /*overwrite*/1);
 706     } else {
 707       // Set DYLD_INSERT_LIBRARIES equal to the runtime dylib name.
 708       setenv(kDyldInsertLibraries, info.dli_fname, /*overwrite*/0);
 709     }
 710     VReport(1, "exec()-ing the program with\n");
 711     VReport(1, "%s=%s\n", kDyldInsertLibraries, new_env);
 712     VReport(1, "to enable wrappers.\n");
 713     execv(program_name.data(), *_NSGetArgv());
 714
 715     // We get here only if execv() failed.
 716     Report("ERROR: The process is launched without DYLD_INSERT_LIBRARIES, "
 717            "which is required for the sanitizer to work. We tried to set the "
 718            "environment variable and re-execute itself, but execv() failed, "
 719            "possibly because of sandbox restrictions. Make sure to launch the "
 720            "executable with:\n%s=%s\n", kDyldInsertLibraries, new_env);
 721     RAW_CHECK("execv failed" && 0);
 722   }
 723
 724   // Verify that interceptors really work.  We'll use dlsym to locate
 725   // "pthread_create", if interceptors are working, it should really point to
 726   // "wrap_pthread_create" within our own dylib.
 727   Dl_info info_pthread_create;
 728   void *dlopen_addr = dlsym(RTLD_DEFAULT, "pthread_create");
 729   RAW_CHECK(dladdr(dlopen_addr, &info_pthread_create));
 730   if (internal_strcmp(info.dli_fname, info_pthread_create.dli_fname) != 0) {
 731     Report(
 732         "ERROR: Interceptors are not working. This may be because %s is "
 733         "loaded too late (e.g. via dlopen). Please launch the executable "
 734         "with:\n%s=%s\n",
 735         SanitizerToolName, kDyldInsertLibraries, info.dli_fname);
 736     RAW_CHECK("interceptors not installed" && 0);
 737   }
 738
 739   if (!lib_is_in_env)
 740     return;
 741
 742   // DYLD_INSERT_LIBRARIES is set and contains the runtime library. Let's remove
 743   // the dylib from the environment variable, because interceptors are installed
 744   // and we don't want our children to inherit the variable.
 745
 746   uptr env_name_len = internal_strlen(kDyldInsertLibraries);
 747   // Allocate memory to hold the previous env var name, its value, the '='
 748   // sign and the '\0' char.
 749   char *new_env = (char*)allocator_for_env.Allocate(
 750       old_env_len + 2 + env_name_len);
 751   RAW_CHECK(new_env);
 752   internal_memset(new_env, '\0', old_env_len + 2 + env_name_len);
 753   internal_strncpy(new_env, kDyldInsertLibraries, env_name_len);
 754   new_env[env_name_len] = '=';
 755   char *new_env_pos = new_env + env_name_len + 1;
 756
 757   // Iterate over colon-separated pieces of |dyld_insert_libraries|.
 758   char *piece_start = dyld_insert_libraries;
 759   char *piece_end = NULL;
 760   char *old_env_end = dyld_insert_libraries + old_env_len;
 761   do {
 762     if (piece_start[0] == ':') piece_start++;
 763     piece_end = internal_strchr(piece_start, ':');
 764     if (!piece_end) piece_end = dyld_insert_libraries + old_env_len;
 765     if ((uptr)(piece_start - dyld_insert_libraries) > old_env_len) break;
 766     uptr piece_len = piece_end - piece_start;
 767
 768     char *filename_start =
 769         (char *)internal_memrchr(piece_start, '/', piece_len);
 770     uptr filename_len = piece_len;
 771     if (filename_start) {
 772       filename_start += 1;
 773       filename_len = piece_len - (filename_start - piece_start);
 774     } else {
 775       filename_start = piece_start;
 776     }
 777
 778     // If the current piece isn't the runtime library name,
 779     // append it to new_env.
 780     if ((dylib_name_len != filename_len) ||
 781         (internal_memcmp(filename_start, dylib_name, dylib_name_len) != 0)) {
 782       if (new_env_pos != new_env + env_name_len + 1) {
 783         new_env_pos[0] = ':';
 784         new_env_pos++;
 785       }
 786       internal_strncpy(new_env_pos, piece_start, piece_len);
 787       new_env_pos += piece_len;
 788     }
 789     // Move on to the next piece.
 790     piece_start = piece_end;
 791   } while (piece_start < old_env_end);
 792
 793   // Can't use setenv() here, because it requires the allocator to be
 794   // initialized.
 795   // FIXME: instead of filtering DYLD_INSERT_LIBRARIES here, do it in
 796   // a separate function called after InitializeAllocator().
 797   if (new_env_pos == new_env + env_name_len + 1) new_env = NULL;
 798   LeakyResetEnv(kDyldInsertLibraries, new_env);
 799 }
 800 #endif  // SANITIZER_GO
 801
 802 char **GetArgv() {
 803   return *_NSGetArgv();
 804 }
 805
 806 #if defined(__aarch64__) && SANITIZER_IOS && !SANITIZER_IOSSIM
 807 // The task_vm_info struct is normally provided by the macOS SDK, but we need
 808 // fields only available in 10.12+. Declare the struct manually to be able to
 809 // build against older SDKs.
 810 struct __sanitizer_task_vm_info {
 811   mach_vm_size_t virtual_size;
 812   integer_t region_count;
 813   integer_t page_size;
 814   mach_vm_size_t resident_size;
 815   mach_vm_size_t resident_size_peak;
 816   mach_vm_size_t device;
 817   mach_vm_size_t device_peak;
 818   mach_vm_size_t internal;
 819   mach_vm_size_t internal_peak;
 820   mach_vm_size_t external;
 821   mach_vm_size_t external_peak;
 822   mach_vm_size_t reusable;
 823   mach_vm_size_t reusable_peak;
 824   mach_vm_size_t purgeable_volatile_pmap;
 825   mach_vm_size_t purgeable_volatile_resident;
 826   mach_vm_size_t purgeable_volatile_virtual;
 827   mach_vm_size_t compressed;
 828   mach_vm_size_t compressed_peak;
 829   mach_vm_size_t compressed_lifetime;
 830   mach_vm_size_t phys_footprint;
 831   mach_vm_address_t min_address;
 832   mach_vm_address_t max_address;
 833 };
 834 #define __SANITIZER_TASK_VM_INFO_COUNT ((mach_msg_type_number_t) \
 835     (sizeof(__sanitizer_task_vm_info) / sizeof(natural_t)))
 836
 837 uptr GetTaskInfoMaxAddress() {
 838   __sanitizer_task_vm_info vm_info = {};
 839   mach_msg_type_number_t count = __SANITIZER_TASK_VM_INFO_COUNT;
 840   int err = task_info(mach_task_self(), TASK_VM_INFO, (int *)&vm_info, &count);
 841   if (err == 0) {
 842     return vm_info.max_address - 1;
 843   } else {
 844     // xnu cannot provide vm address limit
 845     return 0x200000000 - 1;
 846   }
 847 }
 848 #endif
 849
 850 uptr GetMaxVirtualAddress() {
 851 #if SANITIZER_WORDSIZE == 64
 852 # if defined(__aarch64__) && SANITIZER_IOS && !SANITIZER_IOSSIM
 853   // Get the maximum VM address
 854   static uptr max_vm = GetTaskInfoMaxAddress();
 855   CHECK(max_vm);
 856   return max_vm;
 857 # else
 858   return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
 859 # endif
 860 #else  // SANITIZER_WORDSIZE == 32
 861   return (1ULL << 32) - 1;  // 0xffffffff;
 862 #endif  // SANITIZER_WORDSIZE
 863 }
 864
 865 uptr FindAvailableMemoryRange(uptr shadow_size,
 866                               uptr alignment,
 867                               uptr left_padding,
 868                               uptr *largest_gap_found) {
 869   typedef vm_region_submap_short_info_data_64_t RegionInfo;
 870   enum { kRegionInfoSize = VM_REGION_SUBMAP_SHORT_INFO_COUNT_64 };
 871   // Start searching for available memory region past PAGEZERO, which is
 872   // 4KB on 32-bit and 4GB on 64-bit.
 873   mach_vm_address_t start_address =
 874     (SANITIZER_WORDSIZE == 32) ? 0x000000001000 : 0x000100000000;
 875
 876   mach_vm_address_t address = start_address;
 877   mach_vm_address_t free_begin = start_address;
 878   kern_return_t kr = KERN_SUCCESS;
 879   if (largest_gap_found) *largest_gap_found = 0;
 880   while (kr == KERN_SUCCESS) {
 881     mach_vm_size_t vmsize = 0;
 882     natural_t depth = 0;
 883     RegionInfo vminfo;
 884     mach_msg_type_number_t count = kRegionInfoSize;
 885     kr = mach_vm_region_recurse(mach_task_self(), &address, &vmsize, &depth,
 886                                 (vm_region_info_t)&vminfo, &count);
 887     if (free_begin != address) {
 888       // We found a free region [free_begin..address-1].
 889       uptr gap_start = RoundUpTo((uptr)free_begin + left_padding, alignment);
 890       uptr gap_end = RoundDownTo((uptr)address, alignment);
 891       uptr gap_size = gap_end > gap_start ? gap_end - gap_start : 0;
 892       if (shadow_size < gap_size) {
 893         return gap_start;
 894       }
 895
 896       if (largest_gap_found && *largest_gap_found < gap_size) {
 897         *largest_gap_found = gap_size;
 898       }
 899     }
 900     // Move to the next region.
 901     address += vmsize;
 902     free_begin = address;
 903   }
 904
 905   // We looked at all free regions and could not find one large enough.
 906   return 0;
 907 }
 908
 909 // FIXME implement on this platform.
 910 void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size) { }
 911
 912 void SignalContext::DumpAllRegisters(void *context) {
 913   Report("Register values:\n");
 914
 915   ucontext_t *ucontext = (ucontext_t*)context;
 916 # define DUMPREG64(r) \
 917     Printf("%s = 0x%016llx  ", #r, ucontext->uc_mcontext->__ss.__ ## r);
 918 # define DUMPREG32(r) \
 919     Printf("%s = 0x%08x  ", #r, ucontext->uc_mcontext->__ss.__ ## r);
 920 # define DUMPREG_(r)   Printf(" "); DUMPREG(r);
 921 # define DUMPREG__(r)  Printf("  "); DUMPREG(r);
 922 # define DUMPREG___(r) Printf("   "); DUMPREG(r);
 923
 924 # if defined(__x86_64__)
 925 #  define DUMPREG(r) DUMPREG64(r)
 926   DUMPREG(rax); DUMPREG(rbx); DUMPREG(rcx); DUMPREG(rdx); Printf("\n");
 927   DUMPREG(rdi); DUMPREG(rsi); DUMPREG(rbp); DUMPREG(rsp); Printf("\n");
 928   DUMPREG_(r8); DUMPREG_(r9); DUMPREG(r10); DUMPREG(r11); Printf("\n");
 929   DUMPREG(r12); DUMPREG(r13); DUMPREG(r14); DUMPREG(r15); Printf("\n");
 930 # elif defined(__i386__)
 931 #  define DUMPREG(r) DUMPREG32(r)
 932   DUMPREG(eax); DUMPREG(ebx); DUMPREG(ecx); DUMPREG(edx); Printf("\n");
 933   DUMPREG(edi); DUMPREG(esi); DUMPREG(ebp); DUMPREG(esp); Printf("\n");
 934 # elif defined(__aarch64__)
 935 #  define DUMPREG(r) DUMPREG64(r)
 936   DUMPREG_(x[0]); DUMPREG_(x[1]); DUMPREG_(x[2]); DUMPREG_(x[3]); Printf("\n");
 937   DUMPREG_(x[4]); DUMPREG_(x[5]); DUMPREG_(x[6]); DUMPREG_(x[7]); Printf("\n");
 938   DUMPREG_(x[8]); DUMPREG_(x[9]); DUMPREG(x[10]); DUMPREG(x[11]); Printf("\n");
 939   DUMPREG(x[12]); DUMPREG(x[13]); DUMPREG(x[14]); DUMPREG(x[15]); Printf("\n");
 940   DUMPREG(x[16]); DUMPREG(x[17]); DUMPREG(x[18]); DUMPREG(x[19]); Printf("\n");
 941   DUMPREG(x[20]); DUMPREG(x[21]); DUMPREG(x[22]); DUMPREG(x[23]); Printf("\n");
 942   DUMPREG(x[24]); DUMPREG(x[25]); DUMPREG(x[26]); DUMPREG(x[27]); Printf("\n");
 943   DUMPREG(x[28]); DUMPREG___(fp); DUMPREG___(lr); DUMPREG___(sp); Printf("\n");
 944 # elif defined(__arm__)
 945 #  define DUMPREG(r) DUMPREG32(r)
 946   DUMPREG_(r[0]); DUMPREG_(r[1]); DUMPREG_(r[2]); DUMPREG_(r[3]); Printf("\n");
 947   DUMPREG_(r[4]); DUMPREG_(r[5]); DUMPREG_(r[6]); DUMPREG_(r[7]); Printf("\n");
 948   DUMPREG_(r[8]); DUMPREG_(r[9]); DUMPREG(r[10]); DUMPREG(r[11]); Printf("\n");
 949   DUMPREG(r[12]); DUMPREG___(sp); DUMPREG___(lr); DUMPREG___(pc); Printf("\n");
 950 # else
 951 # error "Unknown architecture"
 952 # endif
 953
 954 # undef DUMPREG64
 955 # undef DUMPREG32
 956 # undef DUMPREG_
 957 # undef DUMPREG__
 958 # undef DUMPREG___
 959 # undef DUMPREG
 960 }
 961
 962 static inline bool CompareBaseAddress(const LoadedModule &a,
 963                                       const LoadedModule &b) {
 964   return a.base_address() < b.base_address();
 965 }
 966
 967 void FormatUUID(char *out, uptr size, const u8 *uuid) {
 968   internal_snprintf(out, size,
 969                     "<%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-"
 970                     "%02X%02X%02X%02X%02X%02X>",
 971                     uuid[0], uuid[1], uuid[2], uuid[3], uuid[4], uuid[5],
 972                     uuid[6], uuid[7], uuid[8], uuid[9], uuid[10], uuid[11],
 973                     uuid[12], uuid[13], uuid[14], uuid[15]);
 974 }
 975
 976 void PrintModuleMap() {
 977   Printf("Process module map:\n");
 978   MemoryMappingLayout memory_mapping(false);
 979   InternalMmapVector<LoadedModule> modules(/*initial_capacity*/ 128);
 980   memory_mapping.DumpListOfModules(&modules);
 981   InternalSort(&modules, modules.size(), CompareBaseAddress);
 982   for (uptr i = 0; i < modules.size(); ++i) {
 983     char uuid_str[128];
 984     FormatUUID(uuid_str, sizeof(uuid_str), modules[i].uuid());
 985     Printf("0x%zx-0x%zx %s (%s) %s\n", modules[i].base_address(),
 986            modules[i].max_executable_address(), modules[i].full_name(),
 987            ModuleArchToString(modules[i].arch()), uuid_str);
 988   }
 989   Printf("End of module map.\n");
 990 }
 991
 992 void CheckNoDeepBind(const char *filename, int flag) {
 993   // Do nothing.
 994 }
 995
 996 // FIXME: implement on this platform.
 997 bool GetRandom(void *buffer, uptr length, bool blocking) {
 998   UNIMPLEMENTED();
 999 }
1000
1001 }  // namespace __sanitizer
1002
1003 #endif  // SANITIZER_MAC