libsanitizer/tsan/tsan_platform_linux.cpp

   1 //===-- tsan_platform_linux.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 a part of ThreadSanitizer (TSan), a race detector.
  10 //
  11 // Linux- and BSD-specific code.
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "sanitizer_common/sanitizer_platform.h"
  15 #if SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD
  16
  17 #include "sanitizer_common/sanitizer_common.h"
  18 #include "sanitizer_common/sanitizer_libc.h"
  19 #include "sanitizer_common/sanitizer_linux.h"
  20 #include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
  21 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
  22 #include "sanitizer_common/sanitizer_posix.h"
  23 #include "sanitizer_common/sanitizer_procmaps.h"
  24 #include "sanitizer_common/sanitizer_stackdepot.h"
  25 #include "sanitizer_common/sanitizer_stoptheworld.h"
  26 #include "tsan_flags.h"
  27 #include "tsan_platform.h"
  28 #include "tsan_rtl.h"
  29
  30 #include <fcntl.h>
  31 #include <pthread.h>
  32 #include <signal.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <stdarg.h>
  37 #include <sys/mman.h>
  38 #if SANITIZER_LINUX
  39 #include <sys/personality.h>
  40 #include <setjmp.h>
  41 #endif
  42 #include <sys/syscall.h>
  43 #include <sys/socket.h>
  44 #include <sys/time.h>
  45 #include <sys/types.h>
  46 #include <sys/resource.h>
  47 #include <sys/stat.h>
  48 #include <unistd.h>
  49 #include <sched.h>
  50 #include <dlfcn.h>
  51 #if SANITIZER_LINUX
  52 #define __need_res_state
  53 #include <resolv.h>
  54 #endif
  55
  56 #ifdef sa_handler
  57 # undef sa_handler
  58 #endif
  59
  60 #ifdef sa_sigaction
  61 # undef sa_sigaction
  62 #endif
  63
  64 #if SANITIZER_FREEBSD
  65 extern "C" void *__libc_stack_end;
  66 void *__libc_stack_end = 0;
  67 #endif
  68
  69 #if SANITIZER_LINUX && (defined(__aarch64__) || defined(__loongarch_lp64)) && \
  70     !SANITIZER_GO
  71 # define INIT_LONGJMP_XOR_KEY 1
  72 #else
  73 # define INIT_LONGJMP_XOR_KEY 0
  74 #endif
  75
  76 #if INIT_LONGJMP_XOR_KEY
  77 #include "interception/interception.h"
  78 // Must be declared outside of other namespaces.
  79 DECLARE_REAL(int, _setjmp, void *env)
  80 #endif
  81
  82 namespace __tsan {
  83
  84 #if INIT_LONGJMP_XOR_KEY
  85 static void InitializeLongjmpXorKey();
  86 static uptr longjmp_xor_key;
  87 #endif
  88
  89 // Runtime detected VMA size.
  90 uptr vmaSize;
  91
  92 enum {
  93   MemTotal,
  94   MemShadow,
  95   MemMeta,
  96   MemFile,
  97   MemMmap,
  98   MemHeap,
  99   MemOther,
 100   MemCount,
 101 };
 102
 103 void FillProfileCallback(uptr p, uptr rss, bool file, uptr *mem) {
 104   mem[MemTotal] += rss;
 105   if (p >= ShadowBeg() && p < ShadowEnd())
 106     mem[MemShadow] += rss;
 107   else if (p >= MetaShadowBeg() && p < MetaShadowEnd())
 108     mem[MemMeta] += rss;
 109   else if ((p >= LoAppMemBeg() && p < LoAppMemEnd()) ||
 110            (p >= MidAppMemBeg() && p < MidAppMemEnd()) ||
 111            (p >= HiAppMemBeg() && p < HiAppMemEnd()))
 112     mem[file ? MemFile : MemMmap] += rss;
 113   else if (p >= HeapMemBeg() && p < HeapMemEnd())
 114     mem[MemHeap] += rss;
 115   else
 116     mem[MemOther] += rss;
 117 }
 118
 119 void WriteMemoryProfile(char *buf, uptr buf_size, u64 uptime_ns) {
 120   uptr mem[MemCount];
 121   internal_memset(mem, 0, sizeof(mem));
 122   GetMemoryProfile(FillProfileCallback, mem);
 123   auto meta = ctx->metamap.GetMemoryStats();
 124   StackDepotStats stacks = StackDepotGetStats();
 125   uptr nthread, nlive;
 126   ctx->thread_registry.GetNumberOfThreads(&nthread, &nlive);
 127   uptr trace_mem;
 128   {
 129     Lock l(&ctx->slot_mtx);
 130     trace_mem = ctx->trace_part_total_allocated * sizeof(TracePart);
 131   }
 132   uptr internal_stats[AllocatorStatCount];
 133   internal_allocator()->GetStats(internal_stats);
 134   // All these are allocated from the common mmap region.
 135   mem[MemMmap] -= meta.mem_block + meta.sync_obj + trace_mem +
 136                   stacks.allocated + internal_stats[AllocatorStatMapped];
 137   if (s64(mem[MemMmap]) < 0)
 138     mem[MemMmap] = 0;
 139   internal_snprintf(
 140       buf, buf_size,
 141       "==%zu== %llus [%zu]: RSS %zd MB: shadow:%zd meta:%zd file:%zd"
 142       " mmap:%zd heap:%zd other:%zd intalloc:%zd memblocks:%zd syncobj:%zu"
 143       " trace:%zu stacks=%zd threads=%zu/%zu\n",
 144       internal_getpid(), uptime_ns / (1000 * 1000 * 1000), ctx->global_epoch,
 145       mem[MemTotal] >> 20, mem[MemShadow] >> 20, mem[MemMeta] >> 20,
 146       mem[MemFile] >> 20, mem[MemMmap] >> 20, mem[MemHeap] >> 20,
 147       mem[MemOther] >> 20, internal_stats[AllocatorStatMapped] >> 20,
 148       meta.mem_block >> 20, meta.sync_obj >> 20, trace_mem >> 20,
 149       stacks.allocated >> 20, nlive, nthread);
 150 }
 151
 152 #if !SANITIZER_GO
 153 // Mark shadow for .rodata sections with the special Shadow::kRodata marker.
 154 // Accesses to .rodata can't race, so this saves time, memory and trace space.
 155 static void MapRodata() {
 156   // First create temp file.
 157   const char *tmpdir = GetEnv("TMPDIR");
 158   if (tmpdir == 0)
 159     tmpdir = GetEnv("TEST_TMPDIR");
 160 #ifdef P_tmpdir
 161   if (tmpdir == 0)
 162     tmpdir = P_tmpdir;
 163 #endif
 164   if (tmpdir == 0)
 165     return;
 166   char name[256];
 167   internal_snprintf(name, sizeof(name), "%s/tsan.rodata.%d",
 168                     tmpdir, (int)internal_getpid());
 169   uptr openrv = internal_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
 170   if (internal_iserror(openrv))
 171     return;
 172   internal_unlink(name);  // Unlink it now, so that we can reuse the buffer.
 173   fd_t fd = openrv;
 174   // Fill the file with Shadow::kRodata.
 175   const uptr kMarkerSize = 512 * 1024 / sizeof(RawShadow);
 176   InternalMmapVector<RawShadow> marker(kMarkerSize);
 177   // volatile to prevent insertion of memset
 178   for (volatile RawShadow *p = marker.data(); p < marker.data() + kMarkerSize;
 179        p++)
 180     *p = Shadow::kRodata;
 181   internal_write(fd, marker.data(), marker.size() * sizeof(RawShadow));
 182   // Map the file into memory.
 183   uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE,
 184                             MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
 185   if (internal_iserror(page)) {
 186     internal_close(fd);
 187     return;
 188   }
 189   // Map the file into shadow of .rodata sections.
 190   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 191   // Reusing the buffer 'name'.
 192   MemoryMappedSegment segment(name, ARRAY_SIZE(name));
 193   while (proc_maps.Next(&segment)) {
 194     if (segment.filename[0] != 0 && segment.filename[0] != '[' &&
 195         segment.IsReadable() && segment.IsExecutable() &&
 196         !segment.IsWritable() && IsAppMem(segment.start)) {
 197       // Assume it's .rodata
 198       char *shadow_start = (char *)MemToShadow(segment.start);
 199       char *shadow_end = (char *)MemToShadow(segment.end);
 200       for (char *p = shadow_start; p < shadow_end;
 201            p += marker.size() * sizeof(RawShadow)) {
 202         internal_mmap(
 203             p, Min<uptr>(marker.size() * sizeof(RawShadow), shadow_end - p),
 204             PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
 205       }
 206     }
 207   }
 208   internal_close(fd);
 209 }
 210
 211 void InitializeShadowMemoryPlatform() {
 212   MapRodata();
 213 }
 214
 215 #endif  // #if !SANITIZER_GO
 216
 217 void InitializePlatformEarly() {
 218   vmaSize =
 219     (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
 220 #if defined(__aarch64__)
 221 # if !SANITIZER_GO
 222   if (vmaSize != 39 && vmaSize != 42 && vmaSize != 48) {
 223     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 224     Printf("FATAL: Found %zd - Supported 39, 42 and 48\n", vmaSize);
 225     Die();
 226   }
 227 #else
 228   if (vmaSize != 48) {
 229     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 230     Printf("FATAL: Found %zd - Supported 48\n", vmaSize);
 231     Die();
 232   }
 233 #endif
 234 #elif SANITIZER_LOONGARCH64
 235 # if !SANITIZER_GO
 236   if (vmaSize != 47) {
 237     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 238     Printf("FATAL: Found %zd - Supported 47\n", vmaSize);
 239     Die();
 240   }
 241 # endif
 242 #elif defined(__powerpc64__)
 243 # if !SANITIZER_GO
 244   if (vmaSize != 44 && vmaSize != 46 && vmaSize != 47) {
 245     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 246     Printf("FATAL: Found %zd - Supported 44, 46, and 47\n", vmaSize);
 247     Die();
 248   }
 249 # else
 250   if (vmaSize != 46 && vmaSize != 47) {
 251     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 252     Printf("FATAL: Found %zd - Supported 46, and 47\n", vmaSize);
 253     Die();
 254   }
 255 # endif
 256 #elif defined(__mips64)
 257 # if !SANITIZER_GO
 258   if (vmaSize != 40) {
 259     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 260     Printf("FATAL: Found %zd - Supported 40\n", vmaSize);
 261     Die();
 262   }
 263 # else
 264   if (vmaSize != 47) {
 265     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 266     Printf("FATAL: Found %zd - Supported 47\n", vmaSize);
 267     Die();
 268   }
 269 # endif
 270 #endif
 271 }
 272
 273 void InitializePlatform() {
 274   DisableCoreDumperIfNecessary();
 275
 276   // Go maps shadow memory lazily and works fine with limited address space.
 277   // Unlimited stack is not a problem as well, because the executable
 278   // is not compiled with -pie.
 279 #if !SANITIZER_GO
 280   {
 281     bool reexec = false;
 282     // TSan doesn't play well with unlimited stack size (as stack
 283     // overlaps with shadow memory). If we detect unlimited stack size,
 284     // we re-exec the program with limited stack size as a best effort.
 285     if (StackSizeIsUnlimited()) {
 286       const uptr kMaxStackSize = 32 * 1024 * 1024;
 287       VReport(1, "Program is run with unlimited stack size, which wouldn't "
 288                  "work with ThreadSanitizer.\n"
 289                  "Re-execing with stack size limited to %zd bytes.\n",
 290               kMaxStackSize);
 291       SetStackSizeLimitInBytes(kMaxStackSize);
 292       reexec = true;
 293     }
 294
 295     if (!AddressSpaceIsUnlimited()) {
 296       Report("WARNING: Program is run with limited virtual address space,"
 297              " which wouldn't work with ThreadSanitizer.\n");
 298       Report("Re-execing with unlimited virtual address space.\n");
 299       SetAddressSpaceUnlimited();
 300       reexec = true;
 301     }
 302 #if SANITIZER_ANDROID && (defined(__aarch64__) || defined(__x86_64__))
 303     // After patch "arm64: mm: support ARCH_MMAP_RND_BITS." is introduced in
 304     // linux kernel, the random gap between stack and mapped area is increased
 305     // from 128M to 36G on 39-bit aarch64. As it is almost impossible to cover
 306     // this big range, we should disable randomized virtual space on aarch64.
 307     // ASLR personality check.
 308     int old_personality = personality(0xffffffff);
 309     if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
 310       VReport(1, "WARNING: Program is run with randomized virtual address "
 311               "space, which wouldn't work with ThreadSanitizer.\n"
 312               "Re-execing with fixed virtual address space.\n");
 313       CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
 314       reexec = true;
 315     }
 316
 317 #endif
 318 #if SANITIZER_LINUX && (defined(__aarch64__) || defined(__loongarch_lp64))
 319     // Initialize the xor key used in {sig}{set,long}jump.
 320     InitializeLongjmpXorKey();
 321 #endif
 322     if (reexec)
 323       ReExec();
 324   }
 325
 326   CheckAndProtect();
 327   InitTlsSize();
 328 #endif  // !SANITIZER_GO
 329 }
 330
 331 #if !SANITIZER_GO
 332 // Extract file descriptors passed to glibc internal __res_iclose function.
 333 // This is required to properly "close" the fds, because we do not see internal
 334 // closes within glibc. The code is a pure hack.
 335 int ExtractResolvFDs(void *state, int *fds, int nfd) {
 336 #if SANITIZER_LINUX && !SANITIZER_ANDROID
 337   int cnt = 0;
 338   struct __res_state *statp = (struct __res_state*)state;
 339   for (int i = 0; i < MAXNS && cnt < nfd; i++) {
 340     if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1)
 341       fds[cnt++] = statp->_u._ext.nssocks[i];
 342   }
 343   return cnt;
 344 #else
 345   return 0;
 346 #endif
 347 }
 348
 349 // Extract file descriptors passed via UNIX domain sockets.
 350 // This is required to properly handle "open" of these fds.
 351 // see 'man recvmsg' and 'man 3 cmsg'.
 352 int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) {
 353   int res = 0;
 354   msghdr *msg = (msghdr*)msgp;
 355   struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
 356   for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 357     if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS)
 358       continue;
 359     int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]);
 360     for (int i = 0; i < n; i++) {
 361       fds[res++] = ((int*)CMSG_DATA(cmsg))[i];
 362       if (res == nfd)
 363         return res;
 364     }
 365   }
 366   return res;
 367 }
 368
 369 // Reverse operation of libc stack pointer mangling
 370 static uptr UnmangleLongJmpSp(uptr mangled_sp) {
 371 #if defined(__x86_64__)
 372 # if SANITIZER_LINUX
 373   // Reverse of:
 374   //   xor  %fs:0x30, %rsi
 375   //   rol  $0x11, %rsi
 376   uptr sp;
 377   asm("ror  $0x11,     %0 \n"
 378       "xor  %%fs:0x30, %0 \n"
 379       : "=r" (sp)
 380       : "0" (mangled_sp));
 381   return sp;
 382 # else
 383   return mangled_sp;
 384 # endif
 385 #elif defined(__aarch64__)
 386 # if SANITIZER_LINUX
 387   return mangled_sp ^ longjmp_xor_key;
 388 # else
 389   return mangled_sp;
 390 # endif
 391 #elif defined(__loongarch_lp64)
 392   return mangled_sp ^ longjmp_xor_key;
 393 #elif defined(__powerpc64__)
 394   // Reverse of:
 395   //   ld   r4, -28696(r13)
 396   //   xor  r4, r3, r4
 397   uptr xor_key;
 398   asm("ld  %0, -28696(%%r13)" : "=r" (xor_key));
 399   return mangled_sp ^ xor_key;
 400 #elif defined(__mips__)
 401   return mangled_sp;
 402 #elif defined(__s390x__)
 403   // tcbhead_t.stack_guard
 404   uptr xor_key = ((uptr *)__builtin_thread_pointer())[5];
 405   return mangled_sp ^ xor_key;
 406 #else
 407   #error "Unknown platform"
 408 #endif
 409 }
 410
 411 #if SANITIZER_NETBSD
 412 # ifdef __x86_64__
 413 #  define LONG_JMP_SP_ENV_SLOT 6
 414 # else
 415 #  error unsupported
 416 # endif
 417 #elif defined(__powerpc__)
 418 # define LONG_JMP_SP_ENV_SLOT 0
 419 #elif SANITIZER_FREEBSD
 420 # ifdef __aarch64__
 421 #  define LONG_JMP_SP_ENV_SLOT 1
 422 # else
 423 #  define LONG_JMP_SP_ENV_SLOT 2
 424 # endif
 425 #elif SANITIZER_LINUX
 426 # ifdef __aarch64__
 427 #  define LONG_JMP_SP_ENV_SLOT 13
 428 # elif defined(__loongarch__)
 429 #  define LONG_JMP_SP_ENV_SLOT 1
 430 # elif defined(__mips64)
 431 #  define LONG_JMP_SP_ENV_SLOT 1
 432 # elif defined(__s390x__)
 433 #  define LONG_JMP_SP_ENV_SLOT 9
 434 # else
 435 #  define LONG_JMP_SP_ENV_SLOT 6
 436 # endif
 437 #endif
 438
 439 uptr ExtractLongJmpSp(uptr *env) {
 440   uptr mangled_sp = env[LONG_JMP_SP_ENV_SLOT];
 441   return UnmangleLongJmpSp(mangled_sp);
 442 }
 443
 444 #if INIT_LONGJMP_XOR_KEY
 445 // GLIBC mangles the function pointers in jmp_buf (used in {set,long}*jmp
 446 // functions) by XORing them with a random key.  For AArch64 it is a global
 447 // variable rather than a TCB one (as for x86_64/powerpc).  We obtain the key by
 448 // issuing a setjmp and XORing the SP pointer values to derive the key.
 449 static void InitializeLongjmpXorKey() {
 450   // 1. Call REAL(setjmp), which stores the mangled SP in env.
 451   jmp_buf env;
 452   REAL(_setjmp)(env);
 453
 454   // 2. Retrieve vanilla/mangled SP.
 455   uptr sp;
 456 #ifdef __loongarch__
 457   asm("move  %0, $sp" : "=r" (sp));
 458 #else
 459   asm("mov  %0, sp" : "=r" (sp));
 460 #endif
 461   uptr mangled_sp = ((uptr *)&env)[LONG_JMP_SP_ENV_SLOT];
 462
 463   // 3. xor SPs to obtain key.
 464   longjmp_xor_key = mangled_sp ^ sp;
 465 }
 466 #endif
 467
 468 extern "C" void __tsan_tls_initialization() {}
 469
 470 void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
 471   // Check that the thr object is in tls;
 472   const uptr thr_beg = (uptr)thr;
 473   const uptr thr_end = (uptr)thr + sizeof(*thr);
 474   CHECK_GE(thr_beg, tls_addr);
 475   CHECK_LE(thr_beg, tls_addr + tls_size);
 476   CHECK_GE(thr_end, tls_addr);
 477   CHECK_LE(thr_end, tls_addr + tls_size);
 478   // Since the thr object is huge, skip it.
 479   const uptr pc = StackTrace::GetNextInstructionPc(
 480       reinterpret_cast<uptr>(__tsan_tls_initialization));
 481   MemoryRangeImitateWrite(thr, pc, tls_addr, thr_beg - tls_addr);
 482   MemoryRangeImitateWrite(thr, pc, thr_end, tls_addr + tls_size - thr_end);
 483 }
 484
 485 // Note: this function runs with async signals enabled,
 486 // so it must not touch any tsan state.
 487 int call_pthread_cancel_with_cleanup(int (*fn)(void *arg),
 488                                      void (*cleanup)(void *arg), void *arg) {
 489   // pthread_cleanup_push/pop are hardcore macros mess.
 490   // We can't intercept nor call them w/o including pthread.h.
 491   int res;
 492   pthread_cleanup_push(cleanup, arg);
 493   res = fn(arg);
 494   pthread_cleanup_pop(0);
 495   return res;
 496 }
 497 #endif  // !SANITIZER_GO
 498
 499 #if !SANITIZER_GO
 500 void ReplaceSystemMalloc() { }
 501 #endif
 502
 503 #if !SANITIZER_GO
 504 #if SANITIZER_ANDROID
 505 // On Android, one thread can call intercepted functions after
 506 // DestroyThreadState(), so add a fake thread state for "dead" threads.
 507 static ThreadState *dead_thread_state = nullptr;
 508
 509 ThreadState *cur_thread() {
 510   ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
 511   if (thr == nullptr) {
 512     __sanitizer_sigset_t emptyset;
 513     internal_sigfillset(&emptyset);
 514     __sanitizer_sigset_t oldset;
 515     CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
 516     thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
 517     if (thr == nullptr) {
 518       thr = reinterpret_cast<ThreadState*>(MmapOrDie(sizeof(ThreadState),
 519                                                      "ThreadState"));
 520       *get_android_tls_ptr() = reinterpret_cast<uptr>(thr);
 521       if (dead_thread_state == nullptr) {
 522         dead_thread_state = reinterpret_cast<ThreadState*>(
 523             MmapOrDie(sizeof(ThreadState), "ThreadState"));
 524         dead_thread_state->fast_state.SetIgnoreBit();
 525         dead_thread_state->ignore_interceptors = 1;
 526         dead_thread_state->is_dead = true;
 527         *const_cast<u32*>(&dead_thread_state->tid) = -1;
 528         CHECK_EQ(0, internal_mprotect(dead_thread_state, sizeof(ThreadState),
 529                                       PROT_READ));
 530       }
 531     }
 532     CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
 533   }
 534   return thr;
 535 }
 536
 537 void set_cur_thread(ThreadState *thr) {
 538   *get_android_tls_ptr() = reinterpret_cast<uptr>(thr);
 539 }
 540
 541 void cur_thread_finalize() {
 542   __sanitizer_sigset_t emptyset;
 543   internal_sigfillset(&emptyset);
 544   __sanitizer_sigset_t oldset;
 545   CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
 546   ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
 547   if (thr != dead_thread_state) {
 548     *get_android_tls_ptr() = reinterpret_cast<uptr>(dead_thread_state);
 549     UnmapOrDie(thr, sizeof(ThreadState));
 550   }
 551   CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
 552 }
 553 #endif  // SANITIZER_ANDROID
 554 #endif  // if !SANITIZER_GO
 555
 556 }  // namespace __tsan
 557
 558 #endif  // SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD