libsanitizer/tsan/tsan_platform_linux.cc

   1 //===-- tsan_platform_linux.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 a part of ThreadSanitizer (TSan), a race detector.
   9 //
  10 // Linux- and FreeBSD-specific code.
  11 //===----------------------------------------------------------------------===//
  12
  13
  14 #include "sanitizer_common/sanitizer_platform.h"
  15 #if SANITIZER_LINUX || SANITIZER_FREEBSD
  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_posix.h"
  21 #include "sanitizer_common/sanitizer_posix.h"
  22 #include "sanitizer_common/sanitizer_procmaps.h"
  23 #include "sanitizer_common/sanitizer_stoptheworld.h"
  24 #include "sanitizer_common/sanitizer_stackdepot.h"
  25 #include "tsan_platform.h"
  26 #include "tsan_rtl.h"
  27 #include "tsan_flags.h"
  28
  29 #include <fcntl.h>
  30 #include <pthread.h>
  31 #include <signal.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <stdarg.h>
  36 #include <sys/mman.h>
  37 #if SANITIZER_LINUX
  38 #include <sys/personality.h>
  39 #include <setjmp.h>
  40 #endif
  41 #include <sys/syscall.h>
  42 #include <sys/socket.h>
  43 #include <sys/time.h>
  44 #include <sys/types.h>
  45 #include <sys/resource.h>
  46 #include <sys/stat.h>
  47 #include <unistd.h>
  48 #include <sched.h>
  49 #include <dlfcn.h>
  50 #if SANITIZER_LINUX
  51 #define __need_res_state
  52 #include <resolv.h>
  53 #endif
  54
  55 #ifdef sa_handler
  56 # undef sa_handler
  57 #endif
  58
  59 #ifdef sa_sigaction
  60 # undef sa_sigaction
  61 #endif
  62
  63 #if SANITIZER_FREEBSD
  64 extern "C" void *__libc_stack_end;
  65 void *__libc_stack_end = 0;
  66 #endif
  67
  68 #if SANITIZER_LINUX && defined(__aarch64__)
  69 void InitializeGuardPtr() __attribute__((visibility("hidden")));
  70 #endif
  71
  72 namespace __tsan {
  73
  74 #ifdef TSAN_RUNTIME_VMA
  75 // Runtime detected VMA size.
  76 uptr vmaSize;
  77 #endif
  78
  79 enum {
  80   MemTotal  = 0,
  81   MemShadow = 1,
  82   MemMeta   = 2,
  83   MemFile   = 3,
  84   MemMmap   = 4,
  85   MemTrace  = 5,
  86   MemHeap   = 6,
  87   MemOther  = 7,
  88   MemCount  = 8,
  89 };
  90
  91 void FillProfileCallback(uptr p, uptr rss, bool file,
  92                          uptr *mem, uptr stats_size) {
  93   mem[MemTotal] += rss;
  94   if (p >= ShadowBeg() && p < ShadowEnd())
  95     mem[MemShadow] += rss;
  96   else if (p >= MetaShadowBeg() && p < MetaShadowEnd())
  97     mem[MemMeta] += rss;
  98 #if !SANITIZER_GO
  99   else if (p >= HeapMemBeg() && p < HeapMemEnd())
 100     mem[MemHeap] += rss;
 101   else if (p >= LoAppMemBeg() && p < LoAppMemEnd())
 102     mem[file ? MemFile : MemMmap] += rss;
 103   else if (p >= HiAppMemBeg() && p < HiAppMemEnd())
 104     mem[file ? MemFile : MemMmap] += rss;
 105 #else
 106   else if (p >= AppMemBeg() && p < AppMemEnd())
 107     mem[file ? MemFile : MemMmap] += rss;
 108 #endif
 109   else if (p >= TraceMemBeg() && p < TraceMemEnd())
 110     mem[MemTrace] += rss;
 111   else
 112     mem[MemOther] += rss;
 113 }
 114
 115 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
 116   uptr mem[MemCount];
 117   internal_memset(mem, 0, sizeof(mem[0]) * MemCount);
 118   __sanitizer::GetMemoryProfile(FillProfileCallback, mem, 7);
 119   StackDepotStats *stacks = StackDepotGetStats();
 120   internal_snprintf(buf, buf_size,
 121       "RSS %zd MB: shadow:%zd meta:%zd file:%zd mmap:%zd"
 122       " trace:%zd heap:%zd other:%zd stacks=%zd[%zd] nthr=%zd/%zd\n",
 123       mem[MemTotal] >> 20, mem[MemShadow] >> 20, mem[MemMeta] >> 20,
 124       mem[MemFile] >> 20, mem[MemMmap] >> 20, mem[MemTrace] >> 20,
 125       mem[MemHeap] >> 20, mem[MemOther] >> 20,
 126       stacks->allocated >> 20, stacks->n_uniq_ids,
 127       nlive, nthread);
 128 }
 129
 130 #if SANITIZER_LINUX
 131 void FlushShadowMemoryCallback(
 132     const SuspendedThreadsList &suspended_threads_list,
 133     void *argument) {
 134   ReleaseMemoryPagesToOS(ShadowBeg(), ShadowEnd());
 135 }
 136 #endif
 137
 138 void FlushShadowMemory() {
 139 #if SANITIZER_LINUX
 140   StopTheWorld(FlushShadowMemoryCallback, 0);
 141 #endif
 142 }
 143
 144 #if !SANITIZER_GO
 145 // Mark shadow for .rodata sections with the special kShadowRodata marker.
 146 // Accesses to .rodata can't race, so this saves time, memory and trace space.
 147 static void MapRodata() {
 148   // First create temp file.
 149   const char *tmpdir = GetEnv("TMPDIR");
 150   if (tmpdir == 0)
 151     tmpdir = GetEnv("TEST_TMPDIR");
 152 #ifdef P_tmpdir
 153   if (tmpdir == 0)
 154     tmpdir = P_tmpdir;
 155 #endif
 156   if (tmpdir == 0)
 157     return;
 158   char name[256];
 159   internal_snprintf(name, sizeof(name), "%s/tsan.rodata.%d",
 160                     tmpdir, (int)internal_getpid());
 161   uptr openrv = internal_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
 162   if (internal_iserror(openrv))
 163     return;
 164   internal_unlink(name);  // Unlink it now, so that we can reuse the buffer.
 165   fd_t fd = openrv;
 166   // Fill the file with kShadowRodata.
 167   const uptr kMarkerSize = 512 * 1024 / sizeof(u64);
 168   InternalScopedBuffer<u64> marker(kMarkerSize);
 169   // volatile to prevent insertion of memset
 170   for (volatile u64 *p = marker.data(); p < marker.data() + kMarkerSize; p++)
 171     *p = kShadowRodata;
 172   internal_write(fd, marker.data(), marker.size());
 173   // Map the file into memory.
 174   uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE,
 175                             MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
 176   if (internal_iserror(page)) {
 177     internal_close(fd);
 178     return;
 179   }
 180   // Map the file into shadow of .rodata sections.
 181   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 182   // Reusing the buffer 'name'.
 183   MemoryMappedSegment segment(name, ARRAY_SIZE(name));
 184   while (proc_maps.Next(&segment)) {
 185     if (segment.filename[0] != 0 && segment.filename[0] != '[' &&
 186         segment.IsReadable() && segment.IsExecutable() &&
 187         !segment.IsWritable() && IsAppMem(segment.start)) {
 188       // Assume it's .rodata
 189       char *shadow_start = (char *)MemToShadow(segment.start);
 190       char *shadow_end = (char *)MemToShadow(segment.end);
 191       for (char *p = shadow_start; p < shadow_end; p += marker.size()) {
 192         internal_mmap(p, Min<uptr>(marker.size(), shadow_end - p),
 193                       PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
 194       }
 195     }
 196   }
 197   internal_close(fd);
 198 }
 199
 200 void InitializeShadowMemoryPlatform() {
 201   MapRodata();
 202 }
 203
 204 #endif  // #if !SANITIZER_GO
 205
 206 void InitializePlatformEarly() {
 207 #ifdef TSAN_RUNTIME_VMA
 208   vmaSize =
 209     (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
 210 #if defined(__aarch64__)
 211   if (vmaSize != 39 && vmaSize != 42 && vmaSize != 48) {
 212     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 213     Printf("FATAL: Found %d - Supported 39, 42 and 48\n", vmaSize);
 214     Die();
 215   }
 216 #elif defined(__powerpc64__)
 217   if (vmaSize != 44 && vmaSize != 46) {
 218     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 219     Printf("FATAL: Found %d - Supported 44 and 46\n", vmaSize);
 220     Die();
 221   }
 222 #endif
 223 #endif
 224 }
 225
 226 void InitializePlatform() {
 227   DisableCoreDumperIfNecessary();
 228
 229   // Go maps shadow memory lazily and works fine with limited address space.
 230   // Unlimited stack is not a problem as well, because the executable
 231   // is not compiled with -pie.
 232   if (!SANITIZER_GO) {
 233     bool reexec = false;
 234     // TSan doesn't play well with unlimited stack size (as stack
 235     // overlaps with shadow memory). If we detect unlimited stack size,
 236     // we re-exec the program with limited stack size as a best effort.
 237     if (StackSizeIsUnlimited()) {
 238       const uptr kMaxStackSize = 32 * 1024 * 1024;
 239       VReport(1, "Program is run with unlimited stack size, which wouldn't "
 240                  "work with ThreadSanitizer.\n"
 241                  "Re-execing with stack size limited to %zd bytes.\n",
 242               kMaxStackSize);
 243       SetStackSizeLimitInBytes(kMaxStackSize);
 244       reexec = true;
 245     }
 246
 247     if (!AddressSpaceIsUnlimited()) {
 248       Report("WARNING: Program is run with limited virtual address space,"
 249              " which wouldn't work with ThreadSanitizer.\n");
 250       Report("Re-execing with unlimited virtual address space.\n");
 251       SetAddressSpaceUnlimited();
 252       reexec = true;
 253     }
 254 #if SANITIZER_LINUX && defined(__aarch64__)
 255     // After patch "arm64: mm: support ARCH_MMAP_RND_BITS." is introduced in
 256     // linux kernel, the random gap between stack and mapped area is increased
 257     // from 128M to 36G on 39-bit aarch64. As it is almost impossible to cover
 258     // this big range, we should disable randomized virtual space on aarch64.
 259     int old_personality = personality(0xffffffff);
 260     if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
 261       VReport(1, "WARNING: Program is run with randomized virtual address "
 262               "space, which wouldn't work with ThreadSanitizer.\n"
 263               "Re-execing with fixed virtual address space.\n");
 264       CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
 265       reexec = true;
 266     }
 267     // Initialize the guard pointer used in {sig}{set,long}jump.
 268     InitializeGuardPtr();
 269 #endif
 270     if (reexec)
 271       ReExec();
 272   }
 273
 274 #if !SANITIZER_GO
 275   CheckAndProtect();
 276   InitTlsSize();
 277 #endif
 278 }
 279
 280 #if !SANITIZER_GO
 281 // Extract file descriptors passed to glibc internal __res_iclose function.
 282 // This is required to properly "close" the fds, because we do not see internal
 283 // closes within glibc. The code is a pure hack.
 284 int ExtractResolvFDs(void *state, int *fds, int nfd) {
 285 #if SANITIZER_LINUX && !SANITIZER_ANDROID
 286   int cnt = 0;
 287   struct __res_state *statp = (struct __res_state*)state;
 288   for (int i = 0; i < MAXNS && cnt < nfd; i++) {
 289     if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1)
 290       fds[cnt++] = statp->_u._ext.nssocks[i];
 291   }
 292   return cnt;
 293 #else
 294   return 0;
 295 #endif
 296 }
 297
 298 // Extract file descriptors passed via UNIX domain sockets.
 299 // This is requried to properly handle "open" of these fds.
 300 // see 'man recvmsg' and 'man 3 cmsg'.
 301 int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) {
 302   int res = 0;
 303   msghdr *msg = (msghdr*)msgp;
 304   struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
 305   for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 306     if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS)
 307       continue;
 308     int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]);
 309     for (int i = 0; i < n; i++) {
 310       fds[res++] = ((int*)CMSG_DATA(cmsg))[i];
 311       if (res == nfd)
 312         return res;
 313     }
 314   }
 315   return res;
 316 }
 317
 318 void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
 319   // Check that the thr object is in tls;
 320   const uptr thr_beg = (uptr)thr;
 321   const uptr thr_end = (uptr)thr + sizeof(*thr);
 322   CHECK_GE(thr_beg, tls_addr);
 323   CHECK_LE(thr_beg, tls_addr + tls_size);
 324   CHECK_GE(thr_end, tls_addr);
 325   CHECK_LE(thr_end, tls_addr + tls_size);
 326   // Since the thr object is huge, skip it.
 327   MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr, thr_beg - tls_addr);
 328   MemoryRangeImitateWrite(thr, /*pc=*/2, thr_end,
 329                           tls_addr + tls_size - thr_end);
 330 }
 331
 332 // Note: this function runs with async signals enabled,
 333 // so it must not touch any tsan state.
 334 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
 335     void *abstime), void *c, void *m, void *abstime,
 336     void(*cleanup)(void *arg), void *arg) {
 337   // pthread_cleanup_push/pop are hardcore macros mess.
 338   // We can't intercept nor call them w/o including pthread.h.
 339   int res;
 340   pthread_cleanup_push(cleanup, arg);
 341   res = fn(c, m, abstime);
 342   pthread_cleanup_pop(0);
 343   return res;
 344 }
 345 #endif
 346
 347 #if !SANITIZER_GO
 348 void ReplaceSystemMalloc() { }
 349 #endif
 350
 351 #if !SANITIZER_GO
 352 #if SANITIZER_ANDROID
 353 // On Android, one thread can call intercepted functions after
 354 // DestroyThreadState(), so add a fake thread state for "dead" threads.
 355 static ThreadState *dead_thread_state = nullptr;
 356
 357 ThreadState *cur_thread() {
 358   ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
 359   if (thr == nullptr) {
 360     __sanitizer_sigset_t emptyset;
 361     internal_sigfillset(&emptyset);
 362     __sanitizer_sigset_t oldset;
 363     CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
 364     thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
 365     if (thr == nullptr) {
 366       thr = reinterpret_cast<ThreadState*>(MmapOrDie(sizeof(ThreadState),
 367                                                      "ThreadState"));
 368       *get_android_tls_ptr() = reinterpret_cast<uptr>(thr);
 369       if (dead_thread_state == nullptr) {
 370         dead_thread_state = reinterpret_cast<ThreadState*>(
 371             MmapOrDie(sizeof(ThreadState), "ThreadState"));
 372         dead_thread_state->fast_state.SetIgnoreBit();
 373         dead_thread_state->ignore_interceptors = 1;
 374         dead_thread_state->is_dead = true;
 375         *const_cast<int*>(&dead_thread_state->tid) = -1;
 376         CHECK_EQ(0, internal_mprotect(dead_thread_state, sizeof(ThreadState),
 377                                       PROT_READ));
 378       }
 379     }
 380     CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
 381   }
 382   return thr;
 383 }
 384
 385 void cur_thread_finalize() {
 386   __sanitizer_sigset_t emptyset;
 387   internal_sigfillset(&emptyset);
 388   __sanitizer_sigset_t oldset;
 389   CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
 390   ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
 391   if (thr != dead_thread_state) {
 392     *get_android_tls_ptr() = reinterpret_cast<uptr>(dead_thread_state);
 393     UnmapOrDie(thr, sizeof(ThreadState));
 394   }
 395   CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
 396 }
 397 #endif  // SANITIZER_ANDROID
 398 #endif  // if !SANITIZER_GO
 399
 400 }  // namespace __tsan
 401
 402 #endif  // SANITIZER_LINUX || SANITIZER_FREEBSD