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 
FillProfileCallback(uptr p,uptr rss,bool file,uptr * mem)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 
WriteMemoryProfile(char * buf,uptr buf_size,u64 uptime_ns)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.
MapRodata(char * buffer,uptr size)155 static NOINLINE void MapRodata(char* buffer, uptr size) {
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   internal_snprintf(buffer, size, "%s/tsan.rodata.%d",
167                     tmpdir, (int)internal_getpid());
168   uptr openrv = internal_open(buffer, O_RDWR | O_CREAT | O_EXCL, 0600);
169   if (internal_iserror(openrv))
170     return;
171   internal_unlink(buffer);  // Unlink it now, so that we can reuse the buffer.
172   fd_t fd = openrv;
173   // Fill the file with Shadow::kRodata.
174   const uptr kMarkerSize = 512 * 1024 / sizeof(RawShadow);
175   InternalMmapVector<RawShadow> marker(kMarkerSize);
176   // volatile to prevent insertion of memset
177   for (volatile RawShadow *p = marker.data(); p < marker.data() + kMarkerSize;
178        p++)
179     *p = Shadow::kRodata;
180   internal_write(fd, marker.data(), marker.size() * sizeof(RawShadow));
181   // Map the file into memory.
182   uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE,
183                             MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
184   if (internal_iserror(page)) {
185     internal_close(fd);
186     return;
187   }
188   // Map the file into shadow of .rodata sections.
189   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
190   // Reusing the buffer 'buffer'.
191   MemoryMappedSegment segment(buffer, size);
192   while (proc_maps.Next(&segment)) {
193     if (segment.filename[0] != 0 && segment.filename[0] != '[' &&
194         segment.IsReadable() && segment.IsExecutable() &&
195         !segment.IsWritable() && IsAppMem(segment.start)) {
196       // Assume it's .rodata
197       char *shadow_start = (char *)MemToShadow(segment.start);
198       char *shadow_end = (char *)MemToShadow(segment.end);
199       for (char *p = shadow_start; p < shadow_end;
200            p += marker.size() * sizeof(RawShadow)) {
201         internal_mmap(
202             p, Min<uptr>(marker.size() * sizeof(RawShadow), shadow_end - p),
203             PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
204       }
205     }
206   }
207   internal_close(fd);
208 }
209 
InitializeShadowMemoryPlatform()210 void InitializeShadowMemoryPlatform() {
211   char buffer[256];  // Keep in a different frame.
212   MapRodata(buffer, sizeof(buffer));
213 }
214 
215 #endif  // #if !SANITIZER_GO
216 
217 #  if !SANITIZER_GO
ReExecIfNeeded()218 static void ReExecIfNeeded() {
219   // Go maps shadow memory lazily and works fine with limited address space.
220   // Unlimited stack is not a problem as well, because the executable
221   // is not compiled with -pie.
222   bool reexec = false;
223   // TSan doesn't play well with unlimited stack size (as stack
224   // overlaps with shadow memory). If we detect unlimited stack size,
225   // we re-exec the program with limited stack size as a best effort.
226   if (StackSizeIsUnlimited()) {
227     const uptr kMaxStackSize = 32 * 1024 * 1024;
228     VReport(1,
229             "Program is run with unlimited stack size, which wouldn't "
230             "work with ThreadSanitizer.\n"
231             "Re-execing with stack size limited to %zd bytes.\n",
232             kMaxStackSize);
233     SetStackSizeLimitInBytes(kMaxStackSize);
234     reexec = true;
235   }
236 
237   if (!AddressSpaceIsUnlimited()) {
238     Report(
239         "WARNING: Program is run with limited virtual address space,"
240         " which wouldn't work with ThreadSanitizer.\n");
241     Report("Re-execing with unlimited virtual address space.\n");
242     SetAddressSpaceUnlimited();
243     reexec = true;
244   }
245 
246 #    if SANITIZER_LINUX
247   // ASLR personality check.
248   int old_personality = personality(0xffffffff);
249   bool aslr_on =
250       (old_personality != -1) && ((old_personality & ADDR_NO_RANDOMIZE) == 0);
251 
252 #      if SANITIZER_ANDROID && (defined(__aarch64__) || defined(__x86_64__))
253   // After patch "arm64: mm: support ARCH_MMAP_RND_BITS." is introduced in
254   // linux kernel, the random gap between stack and mapped area is increased
255   // from 128M to 36G on 39-bit aarch64. As it is almost impossible to cover
256   // this big range, we should disable randomized virtual space on aarch64.
257   if (aslr_on) {
258     VReport(1,
259             "WARNING: Program is run with randomized virtual address "
260             "space, which wouldn't work with ThreadSanitizer on Android.\n"
261             "Re-execing with fixed virtual address space.\n");
262     CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
263     reexec = true;
264   }
265 #      endif
266 
267   if (reexec) {
268     // Don't check the address space since we're going to re-exec anyway.
269   } else if (!CheckAndProtect(false, false, false)) {
270     if (aslr_on) {
271       // Disable ASLR if the memory layout was incompatible.
272       // Alternatively, we could just keep re-execing until we get lucky
273       // with a compatible randomized layout, but the risk is that if it's
274       // not an ASLR-related issue, we will be stuck in an infinite loop of
275       // re-execing (unless we change ReExec to pass a parameter of the
276       // number of retries allowed.)
277       VReport(1,
278               "WARNING: ThreadSanitizer: memory layout is incompatible, "
279               "possibly due to high-entropy ASLR.\n"
280               "Re-execing with fixed virtual address space.\n"
281               "N.B. reducing ASLR entropy is preferable.\n");
282       CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
283       reexec = true;
284     } else {
285       VReport(1,
286               "FATAL: ThreadSanitizer: memory layout is incompatible, "
287               "even though ASLR is disabled.\n"
288               "Please file a bug.\n");
289       Die();
290     }
291   }
292 #    endif  // SANITIZER_LINUX
293 
294   if (reexec)
295     ReExec();
296 }
297 #  endif
298 
InitializePlatformEarly()299 void InitializePlatformEarly() {
300   vmaSize =
301     (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
302 #if defined(__aarch64__)
303 # if !SANITIZER_GO
304   if (vmaSize != 39 && vmaSize != 42 && vmaSize != 48) {
305     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
306     Printf("FATAL: Found %zd - Supported 39, 42 and 48\n", vmaSize);
307     Die();
308   }
309 #else
310   if (vmaSize != 48) {
311     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
312     Printf("FATAL: Found %zd - Supported 48\n", vmaSize);
313     Die();
314   }
315 #endif
316 #elif SANITIZER_LOONGARCH64
317 # if !SANITIZER_GO
318   if (vmaSize != 47) {
319     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
320     Printf("FATAL: Found %zd - Supported 47\n", vmaSize);
321     Die();
322   }
323 #    else
324   if (vmaSize != 47) {
325     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
326     Printf("FATAL: Found %zd - Supported 47\n", vmaSize);
327     Die();
328   }
329 #    endif
330 #elif defined(__powerpc64__)
331 # if !SANITIZER_GO
332   if (vmaSize != 44 && vmaSize != 46 && vmaSize != 47) {
333     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
334     Printf("FATAL: Found %zd - Supported 44, 46, and 47\n", vmaSize);
335     Die();
336   }
337 # else
338   if (vmaSize != 46 && vmaSize != 47) {
339     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
340     Printf("FATAL: Found %zd - Supported 46, and 47\n", vmaSize);
341     Die();
342   }
343 # endif
344 #elif defined(__mips64)
345 # if !SANITIZER_GO
346   if (vmaSize != 40) {
347     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
348     Printf("FATAL: Found %zd - Supported 40\n", vmaSize);
349     Die();
350   }
351 # else
352   if (vmaSize != 47) {
353     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
354     Printf("FATAL: Found %zd - Supported 47\n", vmaSize);
355     Die();
356   }
357 # endif
358 #  elif SANITIZER_RISCV64
359   // the bottom half of vma is allocated for userspace
360   vmaSize = vmaSize + 1;
361 #    if !SANITIZER_GO
362   if (vmaSize != 39 && vmaSize != 48) {
363     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
364     Printf("FATAL: Found %zd - Supported 39 and 48\n", vmaSize);
365     Die();
366   }
367 #    endif
368 #  endif
369 
370 #  if !SANITIZER_GO
371   ReExecIfNeeded();
372 #  endif
373 }
374 
InitializePlatform()375 void InitializePlatform() {
376   DisableCoreDumperIfNecessary();
377 
378   // Go maps shadow memory lazily and works fine with limited address space.
379   // Unlimited stack is not a problem as well, because the executable
380   // is not compiled with -pie.
381 #if !SANITIZER_GO
382   {
383 #    if SANITIZER_LINUX && (defined(__aarch64__) || defined(__loongarch_lp64))
384     // Initialize the xor key used in {sig}{set,long}jump.
385     InitializeLongjmpXorKey();
386 #    endif
387   }
388 
389   // Earlier initialization steps already re-exec'ed until we got a compatible
390   // memory layout, so we don't expect any more issues here.
391   if (!CheckAndProtect(true, true, true)) {
392     Printf(
393         "FATAL: ThreadSanitizer: unexpectedly found incompatible memory "
394         "layout.\n");
395     Printf("FATAL: Please file a bug.\n");
396     Die();
397   }
398 
399   InitTlsSize();
400 #endif  // !SANITIZER_GO
401 }
402 
403 #if !SANITIZER_GO
404 // Extract file descriptors passed to glibc internal __res_iclose function.
405 // This is required to properly "close" the fds, because we do not see internal
406 // closes within glibc. The code is a pure hack.
ExtractResolvFDs(void * state,int * fds,int nfd)407 int ExtractResolvFDs(void *state, int *fds, int nfd) {
408 #if SANITIZER_LINUX && !SANITIZER_ANDROID
409   int cnt = 0;
410   struct __res_state *statp = (struct __res_state*)state;
411   for (int i = 0; i < MAXNS && cnt < nfd; i++) {
412     if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1)
413       fds[cnt++] = statp->_u._ext.nssocks[i];
414   }
415   return cnt;
416 #else
417   return 0;
418 #endif
419 }
420 
421 // Extract file descriptors passed via UNIX domain sockets.
422 // This is required to properly handle "open" of these fds.
423 // see 'man recvmsg' and 'man 3 cmsg'.
ExtractRecvmsgFDs(void * msgp,int * fds,int nfd)424 int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) {
425   int res = 0;
426   msghdr *msg = (msghdr*)msgp;
427   struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
428   for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
429     if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS)
430       continue;
431     int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]);
432     for (int i = 0; i < n; i++) {
433       fds[res++] = ((int*)CMSG_DATA(cmsg))[i];
434       if (res == nfd)
435         return res;
436     }
437   }
438   return res;
439 }
440 
441 // Reverse operation of libc stack pointer mangling
UnmangleLongJmpSp(uptr mangled_sp)442 static uptr UnmangleLongJmpSp(uptr mangled_sp) {
443 #if defined(__x86_64__)
444 # if SANITIZER_LINUX
445   // Reverse of:
446   //   xor  %fs:0x30, %rsi
447   //   rol  $0x11, %rsi
448   uptr sp;
449   asm("ror  $0x11,     %0 \n"
450       "xor  %%fs:0x30, %0 \n"
451       : "=r" (sp)
452       : "0" (mangled_sp));
453   return sp;
454 # else
455   return mangled_sp;
456 # endif
457 #elif defined(__aarch64__)
458 # if SANITIZER_LINUX
459   return mangled_sp ^ longjmp_xor_key;
460 # else
461   return mangled_sp;
462 # endif
463 #elif defined(__loongarch_lp64)
464   return mangled_sp ^ longjmp_xor_key;
465 #elif defined(__powerpc64__)
466   // Reverse of:
467   //   ld   r4, -28696(r13)
468   //   xor  r4, r3, r4
469   uptr xor_key;
470   asm("ld  %0, -28696(%%r13)" : "=r" (xor_key));
471   return mangled_sp ^ xor_key;
472 #elif defined(__mips__)
473   return mangled_sp;
474 #    elif SANITIZER_RISCV64
475   return mangled_sp;
476 #    elif defined(__s390x__)
477   // tcbhead_t.stack_guard
478   uptr xor_key = ((uptr *)__builtin_thread_pointer())[5];
479   return mangled_sp ^ xor_key;
480 #    else
481 #      error "Unknown platform"
482 #    endif
483 }
484 
485 #if SANITIZER_NETBSD
486 # ifdef __x86_64__
487 #  define LONG_JMP_SP_ENV_SLOT 6
488 # else
489 #  error unsupported
490 # endif
491 #elif defined(__powerpc__)
492 # define LONG_JMP_SP_ENV_SLOT 0
493 #elif SANITIZER_FREEBSD
494 # ifdef __aarch64__
495 #  define LONG_JMP_SP_ENV_SLOT 1
496 # else
497 #  define LONG_JMP_SP_ENV_SLOT 2
498 # endif
499 #elif SANITIZER_LINUX
500 # ifdef __aarch64__
501 #  define LONG_JMP_SP_ENV_SLOT 13
502 # elif defined(__loongarch__)
503 #  define LONG_JMP_SP_ENV_SLOT 1
504 # elif defined(__mips64)
505 #  define LONG_JMP_SP_ENV_SLOT 1
506 #      elif SANITIZER_RISCV64
507 #        define LONG_JMP_SP_ENV_SLOT 13
508 #      elif defined(__s390x__)
509 #        define LONG_JMP_SP_ENV_SLOT 9
510 #      else
511 #        define LONG_JMP_SP_ENV_SLOT 6
512 #      endif
513 #endif
514 
ExtractLongJmpSp(uptr * env)515 uptr ExtractLongJmpSp(uptr *env) {
516   uptr mangled_sp = env[LONG_JMP_SP_ENV_SLOT];
517   return UnmangleLongJmpSp(mangled_sp);
518 }
519 
520 #if INIT_LONGJMP_XOR_KEY
521 // GLIBC mangles the function pointers in jmp_buf (used in {set,long}*jmp
522 // functions) by XORing them with a random key.  For AArch64 it is a global
523 // variable rather than a TCB one (as for x86_64/powerpc).  We obtain the key by
524 // issuing a setjmp and XORing the SP pointer values to derive the key.
InitializeLongjmpXorKey()525 static void InitializeLongjmpXorKey() {
526   // 1. Call REAL(setjmp), which stores the mangled SP in env.
527   jmp_buf env;
528   REAL(_setjmp)(env);
529 
530   // 2. Retrieve vanilla/mangled SP.
531   uptr sp;
532 #ifdef __loongarch__
533   asm("move  %0, $sp" : "=r" (sp));
534 #else
535   asm("mov  %0, sp" : "=r" (sp));
536 #endif
537   uptr mangled_sp = ((uptr *)&env)[LONG_JMP_SP_ENV_SLOT];
538 
539   // 3. xor SPs to obtain key.
540   longjmp_xor_key = mangled_sp ^ sp;
541 }
542 #endif
543 
__tsan_tls_initialization()544 extern "C" void __tsan_tls_initialization() {}
545 
ImitateTlsWrite(ThreadState * thr,uptr tls_addr,uptr tls_size)546 void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
547   // Check that the thr object is in tls;
548   const uptr thr_beg = (uptr)thr;
549   const uptr thr_end = (uptr)thr + sizeof(*thr);
550   CHECK_GE(thr_beg, tls_addr);
551   CHECK_LE(thr_beg, tls_addr + tls_size);
552   CHECK_GE(thr_end, tls_addr);
553   CHECK_LE(thr_end, tls_addr + tls_size);
554   // Since the thr object is huge, skip it.
555   const uptr pc = StackTrace::GetNextInstructionPc(
556       reinterpret_cast<uptr>(__tsan_tls_initialization));
557   MemoryRangeImitateWrite(thr, pc, tls_addr, thr_beg - tls_addr);
558   MemoryRangeImitateWrite(thr, pc, thr_end, tls_addr + tls_size - thr_end);
559 }
560 
561 // Note: this function runs with async signals enabled,
562 // so it must not touch any tsan state.
call_pthread_cancel_with_cleanup(int (* fn)(void * arg),void (* cleanup)(void * arg),void * arg)563 int call_pthread_cancel_with_cleanup(int (*fn)(void *arg),
564                                      void (*cleanup)(void *arg), void *arg) {
565   // pthread_cleanup_push/pop are hardcore macros mess.
566   // We can't intercept nor call them w/o including pthread.h.
567   int res;
568   pthread_cleanup_push(cleanup, arg);
569   res = fn(arg);
570   pthread_cleanup_pop(0);
571   return res;
572 }
573 #endif  // !SANITIZER_GO
574 
575 #if !SANITIZER_GO
ReplaceSystemMalloc()576 void ReplaceSystemMalloc() { }
577 #endif
578 
579 #if !SANITIZER_GO
580 #if SANITIZER_ANDROID
581 // On Android, one thread can call intercepted functions after
582 // DestroyThreadState(), so add a fake thread state for "dead" threads.
583 static ThreadState *dead_thread_state = nullptr;
584 
cur_thread()585 ThreadState *cur_thread() {
586   ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
587   if (thr == nullptr) {
588     __sanitizer_sigset_t emptyset;
589     internal_sigfillset(&emptyset);
590     __sanitizer_sigset_t oldset;
591     CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
592     thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
593     if (thr == nullptr) {
594       thr = reinterpret_cast<ThreadState*>(MmapOrDie(sizeof(ThreadState),
595                                                      "ThreadState"));
596       *get_android_tls_ptr() = reinterpret_cast<uptr>(thr);
597       if (dead_thread_state == nullptr) {
598         dead_thread_state = reinterpret_cast<ThreadState*>(
599             MmapOrDie(sizeof(ThreadState), "ThreadState"));
600         dead_thread_state->fast_state.SetIgnoreBit();
601         dead_thread_state->ignore_interceptors = 1;
602         dead_thread_state->is_dead = true;
603         *const_cast<u32*>(&dead_thread_state->tid) = -1;
604         CHECK_EQ(0, internal_mprotect(dead_thread_state, sizeof(ThreadState),
605                                       PROT_READ));
606       }
607     }
608     CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
609   }
610   return thr;
611 }
612 
set_cur_thread(ThreadState * thr)613 void set_cur_thread(ThreadState *thr) {
614   *get_android_tls_ptr() = reinterpret_cast<uptr>(thr);
615 }
616 
cur_thread_finalize()617 void cur_thread_finalize() {
618   __sanitizer_sigset_t emptyset;
619   internal_sigfillset(&emptyset);
620   __sanitizer_sigset_t oldset;
621   CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
622   ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
623   if (thr != dead_thread_state) {
624     *get_android_tls_ptr() = reinterpret_cast<uptr>(dead_thread_state);
625     UnmapOrDie(thr, sizeof(ThreadState));
626   }
627   CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
628 }
629 #endif  // SANITIZER_ANDROID
630 #endif  // if !SANITIZER_GO
631 
632 }  // namespace __tsan
633 
634 #endif  // SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD
635