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 FreeBSD-specific code.
  12 //===----------------------------------------------------------------------===//
  13
  14
  15 #include "sanitizer_common/sanitizer_platform.h"
  16 #if SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD
  17
  18 #include "sanitizer_common/sanitizer_common.h"
  19 #include "sanitizer_common/sanitizer_libc.h"
  20 #include "sanitizer_common/sanitizer_linux.h"
  21 #include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
  22 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
  23 #include "sanitizer_common/sanitizer_posix.h"
  24 #include "sanitizer_common/sanitizer_procmaps.h"
  25 #include "sanitizer_common/sanitizer_stoptheworld.h"
  26 #include "sanitizer_common/sanitizer_stackdepot.h"
  27 #include "tsan_platform.h"
  28 #include "tsan_rtl.h"
  29 #include "tsan_flags.h"
  30
  31 #include <fcntl.h>
  32 #include <pthread.h>
  33 #include <signal.h>
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <stdarg.h>
  38 #include <sys/mman.h>
  39 #if SANITIZER_LINUX
  40 #include <sys/personality.h>
  41 #include <setjmp.h>
  42 #endif
  43 #include <sys/syscall.h>
  44 #include <sys/socket.h>
  45 #include <sys/time.h>
  46 #include <sys/types.h>
  47 #include <sys/resource.h>
  48 #include <sys/stat.h>
  49 #include <unistd.h>
  50 #include <sched.h>
  51 #include <dlfcn.h>
  52 #if SANITIZER_LINUX
  53 #define __need_res_state
  54 #include <resolv.h>
  55 #endif
  56
  57 #ifdef sa_handler
  58 # undef sa_handler
  59 #endif
  60
  61 #ifdef sa_sigaction
  62 # undef sa_sigaction
  63 #endif
  64
  65 #if SANITIZER_FREEBSD
  66 extern "C" void *__libc_stack_end;
  67 void *__libc_stack_end = 0;
  68 #endif
  69
  70 #if SANITIZER_LINUX && defined(__aarch64__) && !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 #ifdef TSAN_RUNTIME_VMA
  90 // Runtime detected VMA size.
  91 uptr vmaSize;
  92 #endif
  93
  94 enum {
  95   MemTotal  = 0,
  96   MemShadow = 1,
  97   MemMeta   = 2,
  98   MemFile   = 3,
  99   MemMmap   = 4,
 100   MemTrace  = 5,
 101   MemHeap   = 6,
 102   MemOther  = 7,
 103   MemCount  = 8,
 104 };
 105
 106 void FillProfileCallback(uptr p, uptr rss, bool file,
 107                          uptr *mem, uptr stats_size) {
 108   mem[MemTotal] += rss;
 109   if (p >= ShadowBeg() && p < ShadowEnd())
 110     mem[MemShadow] += rss;
 111   else if (p >= MetaShadowBeg() && p < MetaShadowEnd())
 112     mem[MemMeta] += rss;
 113 #if !SANITIZER_GO
 114   else if (p >= HeapMemBeg() && p < HeapMemEnd())
 115     mem[MemHeap] += rss;
 116   else if (p >= LoAppMemBeg() && p < LoAppMemEnd())
 117     mem[file ? MemFile : MemMmap] += rss;
 118   else if (p >= HiAppMemBeg() && p < HiAppMemEnd())
 119     mem[file ? MemFile : MemMmap] += rss;
 120 #else
 121   else if (p >= AppMemBeg() && p < AppMemEnd())
 122     mem[file ? MemFile : MemMmap] += rss;
 123 #endif
 124   else if (p >= TraceMemBeg() && p < TraceMemEnd())
 125     mem[MemTrace] += rss;
 126   else
 127     mem[MemOther] += rss;
 128 }
 129
 130 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
 131   uptr mem[MemCount];
 132   internal_memset(mem, 0, sizeof(mem[0]) * MemCount);
 133   __sanitizer::GetMemoryProfile(FillProfileCallback, mem, 7);
 134   StackDepotStats *stacks = StackDepotGetStats();
 135   internal_snprintf(buf, buf_size,
 136       "RSS %zd MB: shadow:%zd meta:%zd file:%zd mmap:%zd"
 137       " trace:%zd heap:%zd other:%zd stacks=%zd[%zd] nthr=%zd/%zd\n",
 138       mem[MemTotal] >> 20, mem[MemShadow] >> 20, mem[MemMeta] >> 20,
 139       mem[MemFile] >> 20, mem[MemMmap] >> 20, mem[MemTrace] >> 20,
 140       mem[MemHeap] >> 20, mem[MemOther] >> 20,
 141       stacks->allocated >> 20, stacks->n_uniq_ids,
 142       nlive, nthread);
 143 }
 144
 145 #if SANITIZER_LINUX
 146 void FlushShadowMemoryCallback(
 147     const SuspendedThreadsList &suspended_threads_list,
 148     void *argument) {
 149   ReleaseMemoryPagesToOS(ShadowBeg(), ShadowEnd());
 150 }
 151 #endif
 152
 153 void FlushShadowMemory() {
 154 #if SANITIZER_LINUX
 155   StopTheWorld(FlushShadowMemoryCallback, 0);
 156 #endif
 157 }
 158
 159 #if !SANITIZER_GO
 160 // Mark shadow for .rodata sections with the special kShadowRodata marker.
 161 // Accesses to .rodata can't race, so this saves time, memory and trace space.
 162 static void MapRodata() {
 163   // First create temp file.
 164   const char *tmpdir = GetEnv("TMPDIR");
 165   if (tmpdir == 0)
 166     tmpdir = GetEnv("TEST_TMPDIR");
 167 #ifdef P_tmpdir
 168   if (tmpdir == 0)
 169     tmpdir = P_tmpdir;
 170 #endif
 171   if (tmpdir == 0)
 172     return;
 173   char name[256];
 174   internal_snprintf(name, sizeof(name), "%s/tsan.rodata.%d",
 175                     tmpdir, (int)internal_getpid());
 176   uptr openrv = internal_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
 177   if (internal_iserror(openrv))
 178     return;
 179   internal_unlink(name);  // Unlink it now, so that we can reuse the buffer.
 180   fd_t fd = openrv;
 181   // Fill the file with kShadowRodata.
 182   const uptr kMarkerSize = 512 * 1024 / sizeof(u64);
 183   InternalMmapVector<u64> marker(kMarkerSize);
 184   // volatile to prevent insertion of memset
 185   for (volatile u64 *p = marker.data(); p < marker.data() + kMarkerSize; p++)
 186     *p = kShadowRodata;
 187   internal_write(fd, marker.data(), marker.size() * sizeof(u64));
 188   // Map the file into memory.
 189   uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE,
 190                             MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
 191   if (internal_iserror(page)) {
 192     internal_close(fd);
 193     return;
 194   }
 195   // Map the file into shadow of .rodata sections.
 196   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 197   // Reusing the buffer 'name'.
 198   MemoryMappedSegment segment(name, ARRAY_SIZE(name));
 199   while (proc_maps.Next(&segment)) {
 200     if (segment.filename[0] != 0 && segment.filename[0] != '[' &&
 201         segment.IsReadable() && segment.IsExecutable() &&
 202         !segment.IsWritable() && IsAppMem(segment.start)) {
 203       // Assume it's .rodata
 204       char *shadow_start = (char *)MemToShadow(segment.start);
 205       char *shadow_end = (char *)MemToShadow(segment.end);
 206       for (char *p = shadow_start; p < shadow_end;
 207            p += marker.size() * sizeof(u64)) {
 208         internal_mmap(p, Min<uptr>(marker.size() * sizeof(u64), shadow_end - p),
 209                       PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
 210       }
 211     }
 212   }
 213   internal_close(fd);
 214 }
 215
 216 void InitializeShadowMemoryPlatform() {
 217   MapRodata();
 218 }
 219
 220 #endif  // #if !SANITIZER_GO
 221
 222 void InitializePlatformEarly() {
 223 #ifdef TSAN_RUNTIME_VMA
 224   vmaSize =
 225     (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
 226 #if defined(__aarch64__)
 227 # if !SANITIZER_GO
 228   if (vmaSize != 39 && vmaSize != 42 && vmaSize != 48) {
 229     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 230     Printf("FATAL: Found %zd - Supported 39, 42 and 48\n", vmaSize);
 231     Die();
 232   }
 233 #else
 234   if (vmaSize != 48) {
 235     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 236     Printf("FATAL: Found %zd - Supported 48\n", vmaSize);
 237     Die();
 238   }
 239 #endif
 240 #elif defined(__powerpc64__)
 241 # if !SANITIZER_GO
 242   if (vmaSize != 44 && vmaSize != 46 && vmaSize != 47) {
 243     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 244     Printf("FATAL: Found %zd - Supported 44, 46, and 47\n", vmaSize);
 245     Die();
 246   }
 247 # else
 248   if (vmaSize != 46 && vmaSize != 47) {
 249     Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
 250     Printf("FATAL: Found %zd - Supported 46, and 47\n", vmaSize);
 251     Die();
 252   }
 253 # endif
 254 #endif
 255 #endif
 256 }
 257
 258 void InitializePlatform() {
 259   DisableCoreDumperIfNecessary();
 260
 261   // Go maps shadow memory lazily and works fine with limited address space.
 262   // Unlimited stack is not a problem as well, because the executable
 263   // is not compiled with -pie.
 264 #if !SANITIZER_GO
 265   {
 266     bool reexec = false;
 267     // TSan doesn't play well with unlimited stack size (as stack
 268     // overlaps with shadow memory). If we detect unlimited stack size,
 269     // we re-exec the program with limited stack size as a best effort.
 270     if (StackSizeIsUnlimited()) {
 271       const uptr kMaxStackSize = 32 * 1024 * 1024;
 272       VReport(1, "Program is run with unlimited stack size, which wouldn't "
 273                  "work with ThreadSanitizer.\n"
 274                  "Re-execing with stack size limited to %zd bytes.\n",
 275               kMaxStackSize);
 276       SetStackSizeLimitInBytes(kMaxStackSize);
 277       reexec = true;
 278     }
 279
 280     if (!AddressSpaceIsUnlimited()) {
 281       Report("WARNING: Program is run with limited virtual address space,"
 282              " which wouldn't work with ThreadSanitizer.\n");
 283       Report("Re-execing with unlimited virtual address space.\n");
 284       SetAddressSpaceUnlimited();
 285       reexec = true;
 286     }
 287 #if SANITIZER_LINUX && defined(__aarch64__)
 288     // After patch "arm64: mm: support ARCH_MMAP_RND_BITS." is introduced in
 289     // linux kernel, the random gap between stack and mapped area is increased
 290     // from 128M to 36G on 39-bit aarch64. As it is almost impossible to cover
 291     // this big range, we should disable randomized virtual space on aarch64.
 292     int old_personality = personality(0xffffffff);
 293     if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
 294       VReport(1, "WARNING: Program is run with randomized virtual address "
 295               "space, which wouldn't work with ThreadSanitizer.\n"
 296               "Re-execing with fixed virtual address space.\n");
 297       CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
 298       reexec = true;
 299     }
 300     // Initialize the xor key used in {sig}{set,long}jump.
 301     InitializeLongjmpXorKey();
 302 #endif
 303     if (reexec)
 304       ReExec();
 305   }
 306
 307   CheckAndProtect();
 308   InitTlsSize();
 309 #endif  // !SANITIZER_GO
 310 }
 311
 312 #if !SANITIZER_GO
 313 // Extract file descriptors passed to glibc internal __res_iclose function.
 314 // This is required to properly "close" the fds, because we do not see internal
 315 // closes within glibc. The code is a pure hack.
 316 int ExtractResolvFDs(void *state, int *fds, int nfd) {
 317 #if SANITIZER_LINUX && !SANITIZER_ANDROID
 318   int cnt = 0;
 319   struct __res_state *statp = (struct __res_state*)state;
 320   for (int i = 0; i < MAXNS && cnt < nfd; i++) {
 321     if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1)
 322       fds[cnt++] = statp->_u._ext.nssocks[i];
 323   }
 324   return cnt;
 325 #else
 326   return 0;
 327 #endif
 328 }
 329
 330 // Extract file descriptors passed via UNIX domain sockets.
 331 // This is requried to properly handle "open" of these fds.
 332 // see 'man recvmsg' and 'man 3 cmsg'.
 333 int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) {
 334   int res = 0;
 335   msghdr *msg = (msghdr*)msgp;
 336   struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
 337   for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 338     if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS)
 339       continue;
 340     int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]);
 341     for (int i = 0; i < n; i++) {
 342       fds[res++] = ((int*)CMSG_DATA(cmsg))[i];
 343       if (res == nfd)
 344         return res;
 345     }
 346   }
 347   return res;
 348 }
 349
 350 // Reverse operation of libc stack pointer mangling
 351 static uptr UnmangleLongJmpSp(uptr mangled_sp) {
 352 #if defined(__x86_64__)
 353 # if SANITIZER_LINUX
 354   // Reverse of:
 355   //   xor  %fs:0x30, %rsi
 356   //   rol  $0x11, %rsi
 357   uptr sp;
 358   asm("ror  $0x11,     %0 \n"
 359       "xor  %%fs:0x30, %0 \n"
 360       : "=r" (sp)
 361       : "0" (mangled_sp));
 362   return sp;
 363 # else
 364   return mangled_sp;
 365 # endif
 366 #elif defined(__aarch64__)
 367 # if SANITIZER_LINUX
 368   return mangled_sp ^ longjmp_xor_key;
 369 # else
 370   return mangled_sp;
 371 # endif
 372 #elif defined(__powerpc64__)
 373   // Reverse of:
 374   //   ld   r4, -28696(r13)
 375   //   xor  r4, r3, r4
 376   uptr xor_key;
 377   asm("ld  %0, -28696(%%r13)" : "=r" (xor_key));
 378   return mangled_sp ^ xor_key;
 379 #elif defined(__mips__)
 380   return mangled_sp;
 381 #else
 382   #error "Unknown platform"
 383 #endif
 384 }
 385
 386 #ifdef __powerpc__
 387 # define LONG_JMP_SP_ENV_SLOT 0
 388 #elif SANITIZER_FREEBSD
 389 # define LONG_JMP_SP_ENV_SLOT 2
 390 #elif SANITIZER_NETBSD
 391 # define LONG_JMP_SP_ENV_SLOT 6
 392 #elif SANITIZER_LINUX
 393 # ifdef __aarch64__
 394 #  define LONG_JMP_SP_ENV_SLOT 13
 395 # elif defined(__mips64)
 396 #  define LONG_JMP_SP_ENV_SLOT 1
 397 # else
 398 #  define LONG_JMP_SP_ENV_SLOT 6
 399 # endif
 400 #endif
 401
 402 uptr ExtractLongJmpSp(uptr *env) {
 403   uptr mangled_sp = env[LONG_JMP_SP_ENV_SLOT];
 404   return UnmangleLongJmpSp(mangled_sp);
 405 }
 406
 407 #if INIT_LONGJMP_XOR_KEY
 408 // GLIBC mangles the function pointers in jmp_buf (used in {set,long}*jmp
 409 // functions) by XORing them with a random key.  For AArch64 it is a global
 410 // variable rather than a TCB one (as for x86_64/powerpc).  We obtain the key by
 411 // issuing a setjmp and XORing the SP pointer values to derive the key.
 412 static void InitializeLongjmpXorKey() {
 413   // 1. Call REAL(setjmp), which stores the mangled SP in env.
 414   jmp_buf env;
 415   REAL(_setjmp)(env);
 416
 417   // 2. Retrieve vanilla/mangled SP.
 418   uptr sp;
 419   asm("mov  %0, sp" : "=r" (sp));
 420   uptr mangled_sp = ((uptr *)&env)[LONG_JMP_SP_ENV_SLOT];
 421
 422   // 3. xor SPs to obtain key.
 423   longjmp_xor_key = mangled_sp ^ sp;
 424 }
 425 #endif
 426
 427 void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
 428   // Check that the thr object is in tls;
 429   const uptr thr_beg = (uptr)thr;
 430   const uptr thr_end = (uptr)thr + sizeof(*thr);
 431   CHECK_GE(thr_beg, tls_addr);
 432   CHECK_LE(thr_beg, tls_addr + tls_size);
 433   CHECK_GE(thr_end, tls_addr);
 434   CHECK_LE(thr_end, tls_addr + tls_size);
 435   // Since the thr object is huge, skip it.
 436   MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr, thr_beg - tls_addr);
 437   MemoryRangeImitateWrite(thr, /*pc=*/2, thr_end,
 438                           tls_addr + tls_size - thr_end);
 439 }
 440
 441 // Note: this function runs with async signals enabled,
 442 // so it must not touch any tsan state.
 443 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
 444     void *abstime), void *c, void *m, void *abstime,
 445     void(*cleanup)(void *arg), void *arg) {
 446   // pthread_cleanup_push/pop are hardcore macros mess.
 447   // We can't intercept nor call them w/o including pthread.h.
 448   int res;
 449   pthread_cleanup_push(cleanup, arg);
 450   res = fn(c, m, abstime);
 451   pthread_cleanup_pop(0);
 452   return res;
 453 }
 454 #endif  // !SANITIZER_GO
 455
 456 #if !SANITIZER_GO
 457 void ReplaceSystemMalloc() { }
 458 #endif
 459
 460 #if !SANITIZER_GO
 461 #if SANITIZER_ANDROID
 462 // On Android, one thread can call intercepted functions after
 463 // DestroyThreadState(), so add a fake thread state for "dead" threads.
 464 static ThreadState *dead_thread_state = nullptr;
 465
 466 ThreadState *cur_thread() {
 467   ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
 468   if (thr == nullptr) {
 469     __sanitizer_sigset_t emptyset;
 470     internal_sigfillset(&emptyset);
 471     __sanitizer_sigset_t oldset;
 472     CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
 473     thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
 474     if (thr == nullptr) {
 475       thr = reinterpret_cast<ThreadState*>(MmapOrDie(sizeof(ThreadState),
 476                                                      "ThreadState"));
 477       *get_android_tls_ptr() = reinterpret_cast<uptr>(thr);
 478       if (dead_thread_state == nullptr) {
 479         dead_thread_state = reinterpret_cast<ThreadState*>(
 480             MmapOrDie(sizeof(ThreadState), "ThreadState"));
 481         dead_thread_state->fast_state.SetIgnoreBit();
 482         dead_thread_state->ignore_interceptors = 1;
 483         dead_thread_state->is_dead = true;
 484         *const_cast<int*>(&dead_thread_state->tid) = -1;
 485         CHECK_EQ(0, internal_mprotect(dead_thread_state, sizeof(ThreadState),
 486                                       PROT_READ));
 487       }
 488     }
 489     CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
 490   }
 491   return thr;
 492 }
 493
 494 void set_cur_thread(ThreadState *thr) {
 495   *get_android_tls_ptr() = reinterpret_cast<uptr>(thr);
 496 }
 497
 498 void cur_thread_finalize() {
 499   __sanitizer_sigset_t emptyset;
 500   internal_sigfillset(&emptyset);
 501   __sanitizer_sigset_t oldset;
 502   CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
 503   ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
 504   if (thr != dead_thread_state) {
 505     *get_android_tls_ptr() = reinterpret_cast<uptr>(dead_thread_state);
 506     UnmapOrDie(thr, sizeof(ThreadState));
 507   }
 508   CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
 509 }
 510 #endif  // SANITIZER_ANDROID
 511 #endif  // if !SANITIZER_GO
 512
 513 }  // namespace __tsan
 514
 515 #endif  // SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD