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 <errno.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__)
  70 void InitializeGuardPtr() __attribute__((visibility("hidden")));
  71 #endif
  72
  73 namespace __tsan {
  74
  75 #ifdef TSAN_RUNTIME_VMA
  76 // Runtime detected VMA size.
  77 uptr vmaSize;
  78 #endif
  79
  80 enum {
  81   MemTotal  = 0,
  82   MemShadow = 1,
  83   MemMeta   = 2,
  84   MemFile   = 3,
  85   MemMmap   = 4,
  86   MemTrace  = 5,
  87   MemHeap   = 6,
  88   MemOther  = 7,
  89   MemCount  = 8,
  90 };
  91
  92 void FillProfileCallback(uptr p, uptr rss, bool file,
  93                          uptr *mem, uptr stats_size) {
  94   mem[MemTotal] += rss;
  95   if (p >= ShadowBeg() && p < ShadowEnd())
  96     mem[MemShadow] += rss;
  97   else if (p >= MetaShadowBeg() && p < MetaShadowEnd())
  98     mem[MemMeta] += rss;
  99 #if !SANITIZER_GO
 100   else if (p >= HeapMemBeg() && p < HeapMemEnd())
 101     mem[MemHeap] += rss;
 102   else if (p >= LoAppMemBeg() && p < LoAppMemEnd())
 103     mem[file ? MemFile : MemMmap] += rss;
 104   else if (p >= HiAppMemBeg() && p < HiAppMemEnd())
 105     mem[file ? MemFile : MemMmap] += rss;
 106 #else
 107   else if (p >= AppMemBeg() && p < AppMemEnd())
 108     mem[file ? MemFile : MemMmap] += rss;
 109 #endif
 110   else if (p >= TraceMemBeg() && p < TraceMemEnd())
 111     mem[MemTrace] += rss;
 112   else
 113     mem[MemOther] += rss;
 114 }
 115
 116 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
 117   uptr mem[MemCount];
 118   internal_memset(mem, 0, sizeof(mem[0]) * MemCount);
 119   __sanitizer::GetMemoryProfile(FillProfileCallback, mem, 7);
 120   StackDepotStats *stacks = StackDepotGetStats();
 121   internal_snprintf(buf, buf_size,
 122       "RSS %zd MB: shadow:%zd meta:%zd file:%zd mmap:%zd"
 123       " trace:%zd heap:%zd other:%zd stacks=%zd[%zd] nthr=%zd/%zd\n",
 124       mem[MemTotal] >> 20, mem[MemShadow] >> 20, mem[MemMeta] >> 20,
 125       mem[MemFile] >> 20, mem[MemMmap] >> 20, mem[MemTrace] >> 20,
 126       mem[MemHeap] >> 20, mem[MemOther] >> 20,
 127       stacks->allocated >> 20, stacks->n_uniq_ids,
 128       nlive, nthread);
 129 }
 130
 131 #if SANITIZER_LINUX
 132 void FlushShadowMemoryCallback(
 133     const SuspendedThreadsList &suspended_threads_list,
 134     void *argument) {
 135   ReleaseMemoryToOS(ShadowBeg(), ShadowEnd() - ShadowBeg());
 136 }
 137 #endif
 138
 139 void FlushShadowMemory() {
 140 #if SANITIZER_LINUX
 141   StopTheWorld(FlushShadowMemoryCallback, 0);
 142 #endif
 143 }
 144
 145 #if !SANITIZER_GO
 146 // Mark shadow for .rodata sections with the special kShadowRodata marker.
 147 // Accesses to .rodata can't race, so this saves time, memory and trace space.
 148 static void MapRodata() {
 149   // First create temp file.
 150   const char *tmpdir = GetEnv("TMPDIR");
 151   if (tmpdir == 0)
 152     tmpdir = GetEnv("TEST_TMPDIR");
 153 #ifdef P_tmpdir
 154   if (tmpdir == 0)
 155     tmpdir = P_tmpdir;
 156 #endif
 157   if (tmpdir == 0)
 158     return;
 159   char name[256];
 160   internal_snprintf(name, sizeof(name), "%s/tsan.rodata.%d",
 161                     tmpdir, (int)internal_getpid());
 162   uptr openrv = internal_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
 163   if (internal_iserror(openrv))
 164     return;
 165   internal_unlink(name);  // Unlink it now, so that we can reuse the buffer.
 166   fd_t fd = openrv;
 167   // Fill the file with kShadowRodata.
 168   const uptr kMarkerSize = 512 * 1024 / sizeof(u64);
 169   InternalScopedBuffer<u64> marker(kMarkerSize);
 170   // volatile to prevent insertion of memset
 171   for (volatile u64 *p = marker.data(); p < marker.data() + kMarkerSize; p++)
 172     *p = kShadowRodata;
 173   internal_write(fd, marker.data(), marker.size());
 174   // Map the file into memory.
 175   uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE,
 176                             MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
 177   if (internal_iserror(page)) {
 178     internal_close(fd);
 179     return;
 180   }
 181   // Map the file into shadow of .rodata sections.
 182   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 183   uptr start, end, offset, prot;
 184   // Reusing the buffer 'name'.
 185   while (proc_maps.Next(&start, &end, &offset, name, ARRAY_SIZE(name), &prot)) {
 186     if (name[0] != 0 && name[0] != '['
 187         && (prot & MemoryMappingLayout::kProtectionRead)
 188         && (prot & MemoryMappingLayout::kProtectionExecute)
 189         && !(prot & MemoryMappingLayout::kProtectionWrite)
 190         && IsAppMem(start)) {
 191       // Assume it's .rodata
 192       char *shadow_start = (char*)MemToShadow(start);
 193       char *shadow_end = (char*)MemToShadow(end);
 194       for (char *p = shadow_start; p < shadow_end; p += marker.size()) {
 195         internal_mmap(p, Min<uptr>(marker.size(), shadow_end - p),
 196                       PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
 197       }
 198     }
 199   }
 200   internal_close(fd);
 201 }
 202
 203 void InitializeShadowMemoryPlatform() {
 204   MapRodata();
 205 }
 206
 207 #endif  // #if !SANITIZER_GO
 208
 209 void InitializePlatformEarly() {
 210 #ifdef TSAN_RUNTIME_VMA
 211   vmaSize =
 212     (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
 213 #if defined(__aarch64__)
 214   if (vmaSize != 39 && vmaSize != 42 && vmaSize != 48) {
 215     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 216     Printf("FATAL: Found %d - Supported 39, 42 and 48\n", vmaSize);
 217     Die();
 218   }
 219 #elif defined(__powerpc64__)
 220   if (vmaSize != 44 && vmaSize != 46) {
 221     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 222     Printf("FATAL: Found %d - Supported 44 and 46\n", vmaSize);
 223     Die();
 224   }
 225 #endif
 226 #endif
 227 }
 228
 229 void InitializePlatform() {
 230   DisableCoreDumperIfNecessary();
 231
 232   // Go maps shadow memory lazily and works fine with limited address space.
 233   // Unlimited stack is not a problem as well, because the executable
 234   // is not compiled with -pie.
 235   if (!SANITIZER_GO) {
 236     bool reexec = false;
 237     // TSan doesn't play well with unlimited stack size (as stack
 238     // overlaps with shadow memory). If we detect unlimited stack size,
 239     // we re-exec the program with limited stack size as a best effort.
 240     if (StackSizeIsUnlimited()) {
 241       const uptr kMaxStackSize = 32 * 1024 * 1024;
 242       VReport(1, "Program is run with unlimited stack size, which wouldn't "
 243                  "work with ThreadSanitizer.\n"
 244                  "Re-execing with stack size limited to %zd bytes.\n",
 245               kMaxStackSize);
 246       SetStackSizeLimitInBytes(kMaxStackSize);
 247       reexec = true;
 248     }
 249
 250     if (!AddressSpaceIsUnlimited()) {
 251       Report("WARNING: Program is run with limited virtual address space,"
 252              " which wouldn't work with ThreadSanitizer.\n");
 253       Report("Re-execing with unlimited virtual address space.\n");
 254       SetAddressSpaceUnlimited();
 255       reexec = true;
 256     }
 257 #if SANITIZER_LINUX && defined(__aarch64__)
 258     // After patch "arm64: mm: support ARCH_MMAP_RND_BITS." is introduced in
 259     // linux kernel, the random gap between stack and mapped area is increased
 260     // from 128M to 36G on 39-bit aarch64. As it is almost impossible to cover
 261     // this big range, we should disable randomized virtual space on aarch64.
 262     int old_personality = personality(0xffffffff);
 263     if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
 264       VReport(1, "WARNING: Program is run with randomized virtual address "
 265               "space, which wouldn't work with ThreadSanitizer.\n"
 266               "Re-execing with fixed virtual address space.\n");
 267       CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
 268       reexec = true;
 269     }
 270     // Initialize the guard pointer used in {sig}{set,long}jump.
 271     InitializeGuardPtr();
 272 #endif
 273     if (reexec)
 274       ReExec();
 275   }
 276
 277 #if !SANITIZER_GO
 278   CheckAndProtect();
 279   InitTlsSize();
 280 #endif
 281 }
 282
 283 #if !SANITIZER_GO
 284 // Extract file descriptors passed to glibc internal __res_iclose function.
 285 // This is required to properly "close" the fds, because we do not see internal
 286 // closes within glibc. The code is a pure hack.
 287 int ExtractResolvFDs(void *state, int *fds, int nfd) {
 288 #if SANITIZER_LINUX && !SANITIZER_ANDROID
 289   int cnt = 0;
 290   __res_state *statp = (__res_state*)state;
 291   for (int i = 0; i < MAXNS && cnt < nfd; i++) {
 292     if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1)
 293       fds[cnt++] = statp->_u._ext.nssocks[i];
 294   }
 295   return cnt;
 296 #else
 297   return 0;
 298 #endif
 299 }
 300
 301 // Extract file descriptors passed via UNIX domain sockets.
 302 // This is requried to properly handle "open" of these fds.
 303 // see 'man recvmsg' and 'man 3 cmsg'.
 304 int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) {
 305   int res = 0;
 306   msghdr *msg = (msghdr*)msgp;
 307   struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
 308   for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 309     if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS)
 310       continue;
 311     int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]);
 312     for (int i = 0; i < n; i++) {
 313       fds[res++] = ((int*)CMSG_DATA(cmsg))[i];
 314       if (res == nfd)
 315         return res;
 316     }
 317   }
 318   return res;
 319 }
 320
 321 // Note: this function runs with async signals enabled,
 322 // so it must not touch any tsan state.
 323 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
 324     void *abstime), void *c, void *m, void *abstime,
 325     void(*cleanup)(void *arg), void *arg) {
 326   // pthread_cleanup_push/pop are hardcore macros mess.
 327   // We can't intercept nor call them w/o including pthread.h.
 328   int res;
 329   pthread_cleanup_push(cleanup, arg);
 330   res = fn(c, m, abstime);
 331   pthread_cleanup_pop(0);
 332   return res;
 333 }
 334 #endif
 335
 336 #if !SANITIZER_GO
 337 void ReplaceSystemMalloc() { }
 338 #endif
 339
 340 #if !SANITIZER_GO
 341 #if SANITIZER_ANDROID
 342
 343 #if defined(__aarch64__)
 344 # define __get_tls() \
 345     ({ void** __val; __asm__("mrs %0, tpidr_el0" : "=r"(__val)); __val; })
 346 #elif defined(__x86_64__)
 347 # define __get_tls() \
 348     ({ void** __val; __asm__("mov %%fs:0, %0" : "=r"(__val)); __val; })
 349 #else
 350 #error unsupported architecture
 351 #endif
 352
 353 // On Android, __thread is not supported. So we store the pointer to ThreadState
 354 // in TLS_SLOT_TSAN, which is the tls slot allocated by Android bionic for tsan.
 355 static const int TLS_SLOT_TSAN = 8;
 356 // On Android, one thread can call intercepted functions after
 357 // DestroyThreadState(), so add a fake thread state for "dead" threads.
 358 static ThreadState *dead_thread_state = nullptr;
 359
 360 ThreadState *cur_thread() {
 361   ThreadState* thr = (ThreadState*)__get_tls()[TLS_SLOT_TSAN];
 362   if (thr == nullptr) {
 363     __sanitizer_sigset_t emptyset;
 364     internal_sigfillset(&emptyset);
 365     __sanitizer_sigset_t oldset;
 366     CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
 367     thr = reinterpret_cast<ThreadState*>(__get_tls()[TLS_SLOT_TSAN]);
 368     if (thr == nullptr) {
 369       thr = reinterpret_cast<ThreadState*>(MmapOrDie(sizeof(ThreadState),
 370                                                      "ThreadState"));
 371       __get_tls()[TLS_SLOT_TSAN] = thr;
 372       if (dead_thread_state == nullptr) {
 373         dead_thread_state = reinterpret_cast<ThreadState*>(
 374             MmapOrDie(sizeof(ThreadState), "ThreadState"));
 375         dead_thread_state->fast_state.SetIgnoreBit();
 376         dead_thread_state->ignore_interceptors = 1;
 377         dead_thread_state->is_dead = true;
 378         *const_cast<int*>(&dead_thread_state->tid) = -1;
 379         CHECK_EQ(0, internal_mprotect(dead_thread_state, sizeof(ThreadState),
 380                                       PROT_READ));
 381       }
 382     }
 383     CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
 384   }
 385   return thr;
 386 }
 387
 388 void cur_thread_finalize() {
 389   __sanitizer_sigset_t emptyset;
 390   internal_sigfillset(&emptyset);
 391   __sanitizer_sigset_t oldset;
 392   CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
 393   ThreadState* thr = (ThreadState*)__get_tls()[TLS_SLOT_TSAN];
 394   if (thr != dead_thread_state) {
 395     __get_tls()[TLS_SLOT_TSAN] = dead_thread_state;
 396     UnmapOrDie(thr, sizeof(ThreadState));
 397   }
 398   CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
 399 }
 400 #endif  // SANITIZER_ANDROID
 401 #endif  // if !SANITIZER_GO
 402
 403 }  // namespace __tsan
 404
 405 #endif  // SANITIZER_LINUX || SANITIZER_FREEBSD