libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cc

   1 //===-- sanitizer_linux_libcdep.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 shared between AddressSanitizer and ThreadSanitizer
   9 // run-time libraries and implements linux-specific functions from
  10 // sanitizer_libc.h.
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_platform.h"
  14
  15 #if SANITIZER_FREEBSD || SANITIZER_LINUX
  16
  17 #include "sanitizer_allocator_internal.h"
  18 #include "sanitizer_atomic.h"
  19 #include "sanitizer_common.h"
  20 #include "sanitizer_flags.h"
  21 #include "sanitizer_freebsd.h"
  22 #include "sanitizer_linux.h"
  23 #include "sanitizer_placement_new.h"
  24 #include "sanitizer_procmaps.h"
  25 #include "sanitizer_stacktrace.h"
  26
  27 #if SANITIZER_ANDROID || SANITIZER_FREEBSD
  28 #include <dlfcn.h>  // for dlsym()
  29 #endif
  30
  31 #include <link.h>
  32 #include <pthread.h>
  33 #include <signal.h>
  34 #include <sys/resource.h>
  35 #include <syslog.h>
  36
  37 #if SANITIZER_FREEBSD
  38 #include <pthread_np.h>
  39 #include <osreldate.h>
  40 #define pthread_getattr_np pthread_attr_get_np
  41 #endif
  42
  43 #if SANITIZER_LINUX
  44 #include <sys/prctl.h>
  45 #endif
  46
  47 #if SANITIZER_ANDROID
  48 #include <android/api-level.h>
  49 #endif
  50
  51 #if SANITIZER_ANDROID && __ANDROID_API__ < 21
  52 #include <android/log.h>
  53 #endif
  54
  55 #if !SANITIZER_ANDROID
  56 #include <elf.h>
  57 #include <unistd.h>
  58 #endif
  59
  60 namespace __sanitizer {
  61
  62 SANITIZER_WEAK_ATTRIBUTE int
  63 real_sigaction(int signum, const void *act, void *oldact);
  64
  65 int internal_sigaction(int signum, const void *act, void *oldact) {
  66 #if !SANITIZER_GO
  67   if (&real_sigaction)
  68     return real_sigaction(signum, act, oldact);
  69 #endif
  70   return sigaction(signum, (const struct sigaction *)act,
  71                    (struct sigaction *)oldact);
  72 }
  73
  74 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
  75                                 uptr *stack_bottom) {
  76   CHECK(stack_top);
  77   CHECK(stack_bottom);
  78   if (at_initialization) {
  79     // This is the main thread. Libpthread may not be initialized yet.
  80     struct rlimit rl;
  81     CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0);
  82
  83     // Find the mapping that contains a stack variable.
  84     MemoryMappingLayout proc_maps(/*cache_enabled*/true);
  85     uptr start, end, offset;
  86     uptr prev_end = 0;
  87     while (proc_maps.Next(&start, &end, &offset, nullptr, 0,
  88           /* protection */nullptr)) {
  89       if ((uptr)&rl < end)
  90         break;
  91       prev_end = end;
  92     }
  93     CHECK((uptr)&rl >= start && (uptr)&rl < end);
  94
  95     // Get stacksize from rlimit, but clip it so that it does not overlap
  96     // with other mappings.
  97     uptr stacksize = rl.rlim_cur;
  98     if (stacksize > end - prev_end)
  99       stacksize = end - prev_end;
 100     // When running with unlimited stack size, we still want to set some limit.
 101     // The unlimited stack size is caused by 'ulimit -s unlimited'.
 102     // Also, for some reason, GNU make spawns subprocesses with unlimited stack.
 103     if (stacksize > kMaxThreadStackSize)
 104       stacksize = kMaxThreadStackSize;
 105     *stack_top = end;
 106     *stack_bottom = end - stacksize;
 107     return;
 108   }
 109   pthread_attr_t attr;
 110   pthread_attr_init(&attr);
 111   CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
 112   uptr stacksize = 0;
 113   void *stackaddr = nullptr;
 114   my_pthread_attr_getstack(&attr, &stackaddr, &stacksize);
 115   pthread_attr_destroy(&attr);
 116
 117   CHECK_LE(stacksize, kMaxThreadStackSize);  // Sanity check.
 118   *stack_top = (uptr)stackaddr + stacksize;
 119   *stack_bottom = (uptr)stackaddr;
 120 }
 121
 122 #if !SANITIZER_GO
 123 bool SetEnv(const char *name, const char *value) {
 124   void *f = dlsym(RTLD_NEXT, "setenv");
 125   if (!f)
 126     return false;
 127   typedef int(*setenv_ft)(const char *name, const char *value, int overwrite);
 128   setenv_ft setenv_f;
 129   CHECK_EQ(sizeof(setenv_f), sizeof(f));
 130   internal_memcpy(&setenv_f, &f, sizeof(f));
 131   return setenv_f(name, value, 1) == 0;
 132 }
 133 #endif
 134
 135 bool SanitizerSetThreadName(const char *name) {
 136 #ifdef PR_SET_NAME
 137   return 0 == prctl(PR_SET_NAME, (unsigned long)name, 0, 0, 0);  // NOLINT
 138 #else
 139   return false;
 140 #endif
 141 }
 142
 143 bool SanitizerGetThreadName(char *name, int max_len) {
 144 #ifdef PR_GET_NAME
 145   char buff[17];
 146   if (prctl(PR_GET_NAME, (unsigned long)buff, 0, 0, 0))  // NOLINT
 147     return false;
 148   internal_strncpy(name, buff, max_len);
 149   name[max_len] = 0;
 150   return true;
 151 #else
 152   return false;
 153 #endif
 154 }
 155
 156 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
 157 static uptr g_tls_size;
 158
 159 #ifdef __i386__
 160 # define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall))
 161 #else
 162 # define DL_INTERNAL_FUNCTION
 163 #endif
 164
 165 void InitTlsSize() {
 166 // all current supported platforms have 16 bytes stack alignment
 167   const size_t kStackAlign = 16;
 168   typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION;
 169   get_tls_func get_tls;
 170   void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
 171   CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr));
 172   internal_memcpy(&get_tls, &get_tls_static_info_ptr,
 173                   sizeof(get_tls_static_info_ptr));
 174   CHECK_NE(get_tls, 0);
 175   size_t tls_size = 0;
 176   size_t tls_align = 0;
 177   get_tls(&tls_size, &tls_align);
 178   if (tls_align < kStackAlign)
 179     tls_align = kStackAlign;
 180   g_tls_size = RoundUpTo(tls_size, tls_align);
 181 }
 182 #else
 183 void InitTlsSize() { }
 184 #endif  // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
 185
 186 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) \
 187     || defined(__aarch64__) || defined(__powerpc64__) || defined(__s390__)) \
 188     && SANITIZER_LINUX && !SANITIZER_ANDROID
 189 // sizeof(struct pthread) from glibc.
 190 static atomic_uintptr_t kThreadDescriptorSize;
 191
 192 uptr ThreadDescriptorSize() {
 193   uptr val = atomic_load(&kThreadDescriptorSize, memory_order_relaxed);
 194   if (val)
 195     return val;
 196 #if defined(__x86_64__) || defined(__i386__)
 197 #ifdef _CS_GNU_LIBC_VERSION
 198   char buf[64];
 199   uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf));
 200   if (len < sizeof(buf) && internal_strncmp(buf, "glibc 2.", 8) == 0) {
 201     char *end;
 202     int minor = internal_simple_strtoll(buf + 8, &end, 10);
 203     if (end != buf + 8 && (*end == '\0' || *end == '.')) {
 204       int patch = 0;
 205       if (*end == '.')
 206         // strtoll will return 0 if no valid conversion could be performed
 207         patch = internal_simple_strtoll(end + 1, nullptr, 10);
 208
 209       /* sizeof(struct pthread) values from various glibc versions.  */
 210       if (SANITIZER_X32)
 211         val = 1728;  // Assume only one particular version for x32.
 212       else if (minor <= 3)
 213         val = FIRST_32_SECOND_64(1104, 1696);
 214       else if (minor == 4)
 215         val = FIRST_32_SECOND_64(1120, 1728);
 216       else if (minor == 5)
 217         val = FIRST_32_SECOND_64(1136, 1728);
 218       else if (minor <= 9)
 219         val = FIRST_32_SECOND_64(1136, 1712);
 220       else if (minor == 10)
 221         val = FIRST_32_SECOND_64(1168, 1776);
 222       else if (minor == 11 || (minor == 12 && patch == 1))
 223         val = FIRST_32_SECOND_64(1168, 2288);
 224       else if (minor <= 13)
 225         val = FIRST_32_SECOND_64(1168, 2304);
 226       else
 227         val = FIRST_32_SECOND_64(1216, 2304);
 228     }
 229     if (val)
 230       atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
 231     return val;
 232   }
 233 #endif
 234 #elif defined(__mips__)
 235   // TODO(sagarthakur): add more values as per different glibc versions.
 236   val = FIRST_32_SECOND_64(1152, 1776);
 237   if (val)
 238     atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
 239   return val;
 240 #elif defined(__aarch64__)
 241   // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22.
 242   val = 1776;
 243   atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
 244   return val;
 245 #elif defined(__powerpc64__)
 246   val = 1776; // from glibc.ppc64le 2.20-8.fc21
 247   atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
 248   return val;
 249 #elif defined(__s390__)
 250   val = FIRST_32_SECOND_64(1152, 1776); // valid for glibc 2.22
 251   atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
 252 #endif
 253   return 0;
 254 }
 255
 256 // The offset at which pointer to self is located in the thread descriptor.
 257 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16);
 258
 259 uptr ThreadSelfOffset() {
 260   return kThreadSelfOffset;
 261 }
 262
 263 #if defined(__mips__) || defined(__powerpc64__)
 264 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb
 265 // head structure. It lies before the static tls blocks.
 266 static uptr TlsPreTcbSize() {
 267 # if defined(__mips__)
 268   const uptr kTcbHead = 16; // sizeof (tcbhead_t)
 269 # elif defined(__powerpc64__)
 270   const uptr kTcbHead = 88; // sizeof (tcbhead_t)
 271 # endif
 272   const uptr kTlsAlign = 16;
 273   const uptr kTlsPreTcbSize =
 274     (ThreadDescriptorSize() + kTcbHead + kTlsAlign - 1) & ~(kTlsAlign - 1);
 275   InitTlsSize();
 276   g_tls_size = (g_tls_size + kTlsPreTcbSize + kTlsAlign -1) & ~(kTlsAlign - 1);
 277   return kTlsPreTcbSize;
 278 }
 279 #endif
 280
 281 uptr ThreadSelf() {
 282   uptr descr_addr;
 283 # if defined(__i386__)
 284   asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
 285 # elif defined(__x86_64__)
 286   asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
 287 # elif defined(__mips__)
 288   // MIPS uses TLS variant I. The thread pointer (in hardware register $29)
 289   // points to the end of the TCB + 0x7000. The pthread_descr structure is
 290   // immediately in front of the TCB. TlsPreTcbSize() includes the size of the
 291   // TCB and the size of pthread_descr.
 292   const uptr kTlsTcbOffset = 0x7000;
 293   uptr thread_pointer;
 294   asm volatile(".set push;\
 295                 .set mips64r2;\
 296                 rdhwr %0,$29;\
 297                 .set pop" : "=r" (thread_pointer));
 298   descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize();
 299 # elif defined(__aarch64__)
 300   descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) -
 301                                       ThreadDescriptorSize();
 302 # elif defined(__s390__)
 303   descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer());
 304 # elif defined(__powerpc64__)
 305   // PPC64LE uses TLS variant I. The thread pointer (in GPR 13)
 306   // points to the end of the TCB + 0x7000. The pthread_descr structure is
 307   // immediately in front of the TCB. TlsPreTcbSize() includes the size of the
 308   // TCB and the size of pthread_descr.
 309   const uptr kTlsTcbOffset = 0x7000;
 310   uptr thread_pointer;
 311   asm("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset));
 312   descr_addr = thread_pointer - TlsPreTcbSize();
 313 # else
 314 #  error "unsupported CPU arch"
 315 # endif
 316   return descr_addr;
 317 }
 318 #endif  // (x86_64 || i386 || MIPS) && SANITIZER_LINUX
 319
 320 #if SANITIZER_FREEBSD
 321 static void **ThreadSelfSegbase() {
 322   void **segbase = 0;
 323 # if defined(__i386__)
 324   // sysarch(I386_GET_GSBASE, segbase);
 325   __asm __volatile("mov %%gs:0, %0" : "=r" (segbase));
 326 # elif defined(__x86_64__)
 327   // sysarch(AMD64_GET_FSBASE, segbase);
 328   __asm __volatile("movq %%fs:0, %0" : "=r" (segbase));
 329 # else
 330 #  error "unsupported CPU arch for FreeBSD platform"
 331 # endif
 332   return segbase;
 333 }
 334
 335 uptr ThreadSelf() {
 336   return (uptr)ThreadSelfSegbase()[2];
 337 }
 338 #endif  // SANITIZER_FREEBSD
 339
 340 #if !SANITIZER_GO
 341 static void GetTls(uptr *addr, uptr *size) {
 342 #if SANITIZER_LINUX && !SANITIZER_ANDROID
 343 # if defined(__x86_64__) || defined(__i386__) || defined(__s390__)
 344   *addr = ThreadSelf();
 345   *size = GetTlsSize();
 346   *addr -= *size;
 347   *addr += ThreadDescriptorSize();
 348 # elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__)
 349   *addr = ThreadSelf();
 350   *size = GetTlsSize();
 351 # else
 352   *addr = 0;
 353   *size = 0;
 354 # endif
 355 #elif SANITIZER_FREEBSD
 356   void** segbase = ThreadSelfSegbase();
 357   *addr = 0;
 358   *size = 0;
 359   if (segbase != 0) {
 360     // tcbalign = 16
 361     // tls_size = round(tls_static_space, tcbalign);
 362     // dtv = segbase[1];
 363     // dtv[2] = segbase - tls_static_space;
 364     void **dtv = (void**) segbase[1];
 365     *addr = (uptr) dtv[2];
 366     *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]);
 367   }
 368 #elif SANITIZER_ANDROID
 369   *addr = 0;
 370   *size = 0;
 371 #else
 372 # error "Unknown OS"
 373 #endif
 374 }
 375 #endif
 376
 377 #if !SANITIZER_GO
 378 uptr GetTlsSize() {
 379 #if SANITIZER_FREEBSD || SANITIZER_ANDROID
 380   uptr addr, size;
 381   GetTls(&addr, &size);
 382   return size;
 383 #else
 384   return g_tls_size;
 385 #endif
 386 }
 387 #endif
 388
 389 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
 390                           uptr *tls_addr, uptr *tls_size) {
 391 #if SANITIZER_GO
 392   // Stub implementation for Go.
 393   *stk_addr = *stk_size = *tls_addr = *tls_size = 0;
 394 #else
 395   GetTls(tls_addr, tls_size);
 396
 397   uptr stack_top, stack_bottom;
 398   GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
 399   *stk_addr = stack_bottom;
 400   *stk_size = stack_top - stack_bottom;
 401
 402   if (!main) {
 403     // If stack and tls intersect, make them non-intersecting.
 404     if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) {
 405       CHECK_GT(*tls_addr + *tls_size, *stk_addr);
 406       CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size);
 407       *stk_size -= *tls_size;
 408       *tls_addr = *stk_addr + *stk_size;
 409     }
 410   }
 411 #endif
 412 }
 413
 414 # if !SANITIZER_FREEBSD
 415 typedef ElfW(Phdr) Elf_Phdr;
 416 # elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001  // v9.2
 417 #  define Elf_Phdr XElf32_Phdr
 418 #  define dl_phdr_info xdl_phdr_info
 419 #  define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b))
 420 # endif
 421
 422 struct DlIteratePhdrData {
 423   InternalMmapVector<LoadedModule> *modules;
 424   bool first;
 425 };
 426
 427 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
 428   DlIteratePhdrData *data = (DlIteratePhdrData*)arg;
 429   InternalScopedString module_name(kMaxPathLength);
 430   if (data->first) {
 431     data->first = false;
 432     // First module is the binary itself.
 433     ReadBinaryNameCached(module_name.data(), module_name.size());
 434   } else if (info->dlpi_name) {
 435     module_name.append("%s", info->dlpi_name);
 436   }
 437   if (module_name[0] == '\0')
 438     return 0;
 439   LoadedModule cur_module;
 440   cur_module.set(module_name.data(), info->dlpi_addr);
 441   for (int i = 0; i < info->dlpi_phnum; i++) {
 442     const Elf_Phdr *phdr = &info->dlpi_phdr[i];
 443     if (phdr->p_type == PT_LOAD) {
 444       uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
 445       uptr cur_end = cur_beg + phdr->p_memsz;
 446       bool executable = phdr->p_flags & PF_X;
 447       cur_module.addAddressRange(cur_beg, cur_end, executable);
 448     }
 449   }
 450   data->modules->push_back(cur_module);
 451   return 0;
 452 }
 453
 454 #if SANITIZER_ANDROID && __ANDROID_API__ < 21
 455 extern "C" __attribute__((weak)) int dl_iterate_phdr(
 456     int (*)(struct dl_phdr_info *, size_t, void *), void *);
 457 #endif
 458
 459 void ListOfModules::init() {
 460   clear();
 461 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22
 462   u32 api_level = AndroidGetApiLevel();
 463   // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken.
 464   // The runtime check allows the same library to work with
 465   // both K and L (and future) Android releases.
 466   if (api_level <= ANDROID_LOLLIPOP_MR1) { // L or earlier
 467     MemoryMappingLayout memory_mapping(false);
 468     memory_mapping.DumpListOfModules(&modules_);
 469     return;
 470   }
 471 #endif
 472   DlIteratePhdrData data = {&modules_, true};
 473   dl_iterate_phdr(dl_iterate_phdr_cb, &data);
 474 }
 475
 476 // getrusage does not give us the current RSS, only the max RSS.
 477 // Still, this is better than nothing if /proc/self/statm is not available
 478 // for some reason, e.g. due to a sandbox.
 479 static uptr GetRSSFromGetrusage() {
 480   struct rusage usage;
 481   if (getrusage(RUSAGE_SELF, &usage))  // Failed, probably due to a sandbox.
 482     return 0;
 483   return usage.ru_maxrss << 10;  // ru_maxrss is in Kb.
 484 }
 485
 486 uptr GetRSS() {
 487   if (!common_flags()->can_use_proc_maps_statm)
 488     return GetRSSFromGetrusage();
 489   fd_t fd = OpenFile("/proc/self/statm", RdOnly);
 490   if (fd == kInvalidFd)
 491     return GetRSSFromGetrusage();
 492   char buf[64];
 493   uptr len = internal_read(fd, buf, sizeof(buf) - 1);
 494   internal_close(fd);
 495   if ((sptr)len <= 0)
 496     return 0;
 497   buf[len] = 0;
 498   // The format of the file is:
 499   // 1084 89 69 11 0 79 0
 500   // We need the second number which is RSS in pages.
 501   char *pos = buf;
 502   // Skip the first number.
 503   while (*pos >= '0' && *pos <= '9')
 504     pos++;
 505   // Skip whitespaces.
 506   while (!(*pos >= '0' && *pos <= '9') && *pos != 0)
 507     pos++;
 508   // Read the number.
 509   uptr rss = 0;
 510   while (*pos >= '0' && *pos <= '9')
 511     rss = rss * 10 + *pos++ - '0';
 512   return rss * GetPageSizeCached();
 513 }
 514
 515 // 64-bit Android targets don't provide the deprecated __android_log_write.
 516 // Starting with the L release, syslog() works and is preferable to
 517 // __android_log_write.
 518 #if SANITIZER_LINUX
 519
 520 #if SANITIZER_ANDROID
 521 static atomic_uint8_t android_log_initialized;
 522
 523 void AndroidLogInit() {
 524   openlog(GetProcessName(), 0, LOG_USER);
 525   atomic_store(&android_log_initialized, 1, memory_order_release);
 526 }
 527
 528 static bool ShouldLogAfterPrintf() {
 529   return atomic_load(&android_log_initialized, memory_order_acquire);
 530 }
 531 #else
 532 void AndroidLogInit() {}
 533
 534 static bool ShouldLogAfterPrintf() { return true; }
 535 #endif  // SANITIZER_ANDROID
 536
 537 void WriteOneLineToSyslog(const char *s) {
 538 #if SANITIZER_ANDROID &&__ANDROID_API__ < 21
 539   __android_log_write(ANDROID_LOG_INFO, NULL, s);
 540 #else
 541   syslog(LOG_INFO, "%s", s);
 542 #endif
 543 }
 544
 545 void LogMessageOnPrintf(const char *str) {
 546   if (common_flags()->log_to_syslog && ShouldLogAfterPrintf())
 547     WriteToSyslog(str);
 548 }
 549
 550 #endif // SANITIZER_LINUX
 551
 552 } // namespace __sanitizer
 553
 554 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX