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
  36 #if SANITIZER_FREEBSD
  37 #include <pthread_np.h>
  38 #include <osreldate.h>
  39 #define pthread_getattr_np pthread_attr_get_np
  40 #endif
  41
  42 #if SANITIZER_LINUX
  43 #include <sys/prctl.h>
  44 #endif
  45
  46 #if SANITIZER_ANDROID
  47 #include <android/api-level.h>
  48 #endif
  49
  50 #if SANITIZER_ANDROID && __ANDROID_API__ < 21
  51 #include <android/log.h>
  52 #else
  53 #include <syslog.h>
  54 #endif
  55
  56 #if !SANITIZER_ANDROID
  57 #include <elf.h>
  58 #include <unistd.h>
  59 #endif
  60
  61 namespace __sanitizer {
  62
  63 SANITIZER_WEAK_ATTRIBUTE int
  64 real_sigaction(int signum, const void *act, void *oldact);
  65
  66 int internal_sigaction(int signum, const void *act, void *oldact) {
  67 #if !SANITIZER_GO
  68   if (&real_sigaction)
  69     return real_sigaction(signum, act, oldact);
  70 #endif
  71   return sigaction(signum, (const struct sigaction *)act,
  72                    (struct sigaction *)oldact);
  73 }
  74
  75 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
  76                                 uptr *stack_bottom) {
  77   CHECK(stack_top);
  78   CHECK(stack_bottom);
  79   if (at_initialization) {
  80     // This is the main thread. Libpthread may not be initialized yet.
  81     struct rlimit rl;
  82     CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0);
  83
  84     // Find the mapping that contains a stack variable.
  85     MemoryMappingLayout proc_maps(/*cache_enabled*/true);
  86     uptr start, end, offset;
  87     uptr prev_end = 0;
  88     while (proc_maps.Next(&start, &end, &offset, nullptr, 0,
  89           /* protection */nullptr)) {
  90       if ((uptr)&rl < end)
  91         break;
  92       prev_end = end;
  93     }
  94     CHECK((uptr)&rl >= start && (uptr)&rl < end);
  95
  96     // Get stacksize from rlimit, but clip it so that it does not overlap
  97     // with other mappings.
  98     uptr stacksize = rl.rlim_cur;
  99     if (stacksize > end - prev_end)
 100       stacksize = end - prev_end;
 101     // When running with unlimited stack size, we still want to set some limit.
 102     // The unlimited stack size is caused by 'ulimit -s unlimited'.
 103     // Also, for some reason, GNU make spawns subprocesses with unlimited stack.
 104     if (stacksize > kMaxThreadStackSize)
 105       stacksize = kMaxThreadStackSize;
 106     *stack_top = end;
 107     *stack_bottom = end - stacksize;
 108     return;
 109   }
 110   pthread_attr_t attr;
 111   pthread_attr_init(&attr);
 112   CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
 113   uptr stacksize = 0;
 114   void *stackaddr = nullptr;
 115   my_pthread_attr_getstack(&attr, &stackaddr, &stacksize);
 116   pthread_attr_destroy(&attr);
 117
 118   CHECK_LE(stacksize, kMaxThreadStackSize);  // Sanity check.
 119   *stack_top = (uptr)stackaddr + stacksize;
 120   *stack_bottom = (uptr)stackaddr;
 121 }
 122
 123 #if !SANITIZER_GO
 124 bool SetEnv(const char *name, const char *value) {
 125   void *f = dlsym(RTLD_NEXT, "setenv");
 126   if (!f)
 127     return false;
 128   typedef int(*setenv_ft)(const char *name, const char *value, int overwrite);
 129   setenv_ft setenv_f;
 130   CHECK_EQ(sizeof(setenv_f), sizeof(f));
 131   internal_memcpy(&setenv_f, &f, sizeof(f));
 132   return setenv_f(name, value, 1) == 0;
 133 }
 134 #endif
 135
 136 bool SanitizerSetThreadName(const char *name) {
 137 #ifdef PR_SET_NAME
 138   return 0 == prctl(PR_SET_NAME, (unsigned long)name, 0, 0, 0);  // NOLINT
 139 #else
 140   return false;
 141 #endif
 142 }
 143
 144 bool SanitizerGetThreadName(char *name, int max_len) {
 145 #ifdef PR_GET_NAME
 146   char buff[17];
 147   if (prctl(PR_GET_NAME, (unsigned long)buff, 0, 0, 0))  // NOLINT
 148     return false;
 149   internal_strncpy(name, buff, max_len);
 150   name[max_len] = 0;
 151   return true;
 152 #else
 153   return false;
 154 #endif
 155 }
 156
 157 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
 158 static uptr g_tls_size;
 159 #endif
 160
 161 #ifdef __i386__
 162 # define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall))
 163 #else
 164 # define DL_INTERNAL_FUNCTION
 165 #endif
 166
 167 #if defined(__mips__) || defined(__powerpc64__)
 168 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb
 169 // head structure. It lies before the static tls blocks.
 170 static uptr TlsPreTcbSize() {
 171 # if defined(__mips__)
 172   const uptr kTcbHead = 16; // sizeof (tcbhead_t)
 173 # elif defined(__powerpc64__)
 174   const uptr kTcbHead = 88; // sizeof (tcbhead_t)
 175 # endif
 176   const uptr kTlsAlign = 16;
 177   const uptr kTlsPreTcbSize =
 178     (ThreadDescriptorSize() + kTcbHead + kTlsAlign - 1) & ~(kTlsAlign - 1);
 179   InitTlsSize();
 180   g_tls_size = (g_tls_size + kTlsPreTcbSize + kTlsAlign -1) & ~(kTlsAlign - 1);
 181   return kTlsPreTcbSize;
 182 }
 183 #endif
 184
 185 void InitTlsSize() {
 186 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
 187 // all current supported platforms have 16 bytes stack alignment
 188   const size_t kStackAlign = 16;
 189   typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION;
 190   get_tls_func get_tls;
 191   void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
 192   CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr));
 193   internal_memcpy(&get_tls, &get_tls_static_info_ptr,
 194                   sizeof(get_tls_static_info_ptr));
 195   CHECK_NE(get_tls, 0);
 196   size_t tls_size = 0;
 197   size_t tls_align = 0;
 198   get_tls(&tls_size, &tls_align);
 199   if (tls_align < kStackAlign)
 200     tls_align = kStackAlign;
 201   g_tls_size = RoundUpTo(tls_size, tls_align);
 202 #endif  // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
 203 }
 204
 205 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) \
 206     || defined(__aarch64__) || defined(__powerpc64__)) \
 207     && SANITIZER_LINUX && !SANITIZER_ANDROID
 208 // sizeof(struct pthread) from glibc.
 209 static atomic_uintptr_t kThreadDescriptorSize;
 210
 211 uptr ThreadDescriptorSize() {
 212   uptr val = atomic_load(&kThreadDescriptorSize, memory_order_relaxed);
 213   if (val)
 214     return val;
 215 #if defined(__x86_64__) || defined(__i386__)
 216 #ifdef _CS_GNU_LIBC_VERSION
 217   char buf[64];
 218   uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf));
 219   if (len < sizeof(buf) && internal_strncmp(buf, "glibc 2.", 8) == 0) {
 220     char *end;
 221     int minor = internal_simple_strtoll(buf + 8, &end, 10);
 222     if (end != buf + 8 && (*end == '\0' || *end == '.')) {
 223       /* sizeof(struct pthread) values from various glibc versions.  */
 224       if (SANITIZER_X32)
 225         val = 1728;  // Assume only one particular version for x32.
 226       else if (minor <= 3)
 227         val = FIRST_32_SECOND_64(1104, 1696);
 228       else if (minor == 4)
 229         val = FIRST_32_SECOND_64(1120, 1728);
 230       else if (minor == 5)
 231         val = FIRST_32_SECOND_64(1136, 1728);
 232       else if (minor <= 9)
 233         val = FIRST_32_SECOND_64(1136, 1712);
 234       else if (minor == 10)
 235         val = FIRST_32_SECOND_64(1168, 1776);
 236       else if (minor <= 12)
 237         val = FIRST_32_SECOND_64(1168, 2288);
 238       else if (minor == 13)
 239         val = FIRST_32_SECOND_64(1168, 2304);
 240       else
 241         val = FIRST_32_SECOND_64(1216, 2304);
 242     }
 243     if (val)
 244       atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
 245     return val;
 246   }
 247 #endif
 248 #elif defined(__mips__)
 249   // TODO(sagarthakur): add more values as per different glibc versions.
 250   val = FIRST_32_SECOND_64(1152, 1776);
 251   if (val)
 252     atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
 253   return val;
 254 #elif defined(__aarch64__)
 255   // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22.
 256   val = 1776;
 257   atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
 258   return val;
 259 #elif defined(__powerpc64__)
 260   val = 1776; // from glibc.ppc64le 2.20-8.fc21
 261   atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
 262   return val;
 263 #endif
 264   return 0;
 265 }
 266
 267 // The offset at which pointer to self is located in the thread descriptor.
 268 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16);
 269
 270 uptr ThreadSelfOffset() {
 271   return kThreadSelfOffset;
 272 }
 273
 274 uptr ThreadSelf() {
 275   uptr descr_addr;
 276 # if defined(__i386__)
 277   asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
 278 # elif defined(__x86_64__)
 279   asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
 280 # elif defined(__mips__)
 281   // MIPS uses TLS variant I. The thread pointer (in hardware register $29)
 282   // points to the end of the TCB + 0x7000. The pthread_descr structure is
 283   // immediately in front of the TCB. TlsPreTcbSize() includes the size of the
 284   // TCB and the size of pthread_descr.
 285   const uptr kTlsTcbOffset = 0x7000;
 286   uptr thread_pointer;
 287   asm volatile(".set push;\
 288                 .set mips64r2;\
 289                 rdhwr %0,$29;\
 290                 .set pop" : "=r" (thread_pointer));
 291   descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize();
 292 # elif defined(__aarch64__)
 293   descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer());
 294 # elif defined(__powerpc64__)
 295   // PPC64LE uses TLS variant I. The thread pointer (in GPR 13)
 296   // points to the end of the TCB + 0x7000. The pthread_descr structure is
 297   // immediately in front of the TCB. TlsPreTcbSize() includes the size of the
 298   // TCB and the size of pthread_descr.
 299   const uptr kTlsTcbOffset = 0x7000;
 300   uptr thread_pointer;
 301   asm("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset));
 302   descr_addr = thread_pointer - TlsPreTcbSize();
 303 # else
 304 #  error "unsupported CPU arch"
 305 # endif
 306   return descr_addr;
 307 }
 308 #endif  // (x86_64 || i386 || MIPS) && SANITIZER_LINUX
 309
 310 #if SANITIZER_FREEBSD
 311 static void **ThreadSelfSegbase() {
 312   void **segbase = 0;
 313 # if defined(__i386__)
 314   // sysarch(I386_GET_GSBASE, segbase);
 315   __asm __volatile("mov %%gs:0, %0" : "=r" (segbase));
 316 # elif defined(__x86_64__)
 317   // sysarch(AMD64_GET_FSBASE, segbase);
 318   __asm __volatile("movq %%fs:0, %0" : "=r" (segbase));
 319 # else
 320 #  error "unsupported CPU arch for FreeBSD platform"
 321 # endif
 322   return segbase;
 323 }
 324
 325 uptr ThreadSelf() {
 326   return (uptr)ThreadSelfSegbase()[2];
 327 }
 328 #endif  // SANITIZER_FREEBSD
 329
 330 #if !SANITIZER_GO
 331 static void GetTls(uptr *addr, uptr *size) {
 332 #if SANITIZER_LINUX && !SANITIZER_ANDROID
 333 # if defined(__x86_64__) || defined(__i386__)
 334   *addr = ThreadSelf();
 335   *size = GetTlsSize();
 336   *addr -= *size;
 337   *addr += ThreadDescriptorSize();
 338 # elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__)
 339   *addr = ThreadSelf();
 340   *size = GetTlsSize();
 341 # else
 342   *addr = 0;
 343   *size = 0;
 344 # endif
 345 #elif SANITIZER_FREEBSD
 346   void** segbase = ThreadSelfSegbase();
 347   *addr = 0;
 348   *size = 0;
 349   if (segbase != 0) {
 350     // tcbalign = 16
 351     // tls_size = round(tls_static_space, tcbalign);
 352     // dtv = segbase[1];
 353     // dtv[2] = segbase - tls_static_space;
 354     void **dtv = (void**) segbase[1];
 355     *addr = (uptr) dtv[2];
 356     *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]);
 357   }
 358 #elif SANITIZER_ANDROID
 359   *addr = 0;
 360   *size = 0;
 361 #else
 362 # error "Unknown OS"
 363 #endif
 364 }
 365 #endif
 366
 367 #if !SANITIZER_GO
 368 uptr GetTlsSize() {
 369 #if SANITIZER_FREEBSD || SANITIZER_ANDROID
 370   uptr addr, size;
 371   GetTls(&addr, &size);
 372   return size;
 373 #else
 374   return g_tls_size;
 375 #endif
 376 }
 377 #endif
 378
 379 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
 380                           uptr *tls_addr, uptr *tls_size) {
 381 #if SANITIZER_GO
 382   // Stub implementation for Go.
 383   *stk_addr = *stk_size = *tls_addr = *tls_size = 0;
 384 #else
 385   GetTls(tls_addr, tls_size);
 386
 387   uptr stack_top, stack_bottom;
 388   GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
 389   *stk_addr = stack_bottom;
 390   *stk_size = stack_top - stack_bottom;
 391
 392   if (!main) {
 393     // If stack and tls intersect, make them non-intersecting.
 394     if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) {
 395       CHECK_GT(*tls_addr + *tls_size, *stk_addr);
 396       CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size);
 397       *stk_size -= *tls_size;
 398       *tls_addr = *stk_addr + *stk_size;
 399     }
 400   }
 401 #endif
 402 }
 403
 404 # if !SANITIZER_FREEBSD
 405 typedef ElfW(Phdr) Elf_Phdr;
 406 # elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001  // v9.2
 407 #  define Elf_Phdr XElf32_Phdr
 408 #  define dl_phdr_info xdl_phdr_info
 409 #  define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b))
 410 # endif
 411
 412 struct DlIteratePhdrData {
 413   LoadedModule *modules;
 414   uptr current_n;
 415   bool first;
 416   uptr max_n;
 417   string_predicate_t filter;
 418 };
 419
 420 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
 421   DlIteratePhdrData *data = (DlIteratePhdrData*)arg;
 422   if (data->current_n == data->max_n)
 423     return 0;
 424   InternalScopedString module_name(kMaxPathLength);
 425   if (data->first) {
 426     data->first = false;
 427     // First module is the binary itself.
 428     ReadBinaryNameCached(module_name.data(), module_name.size());
 429   } else if (info->dlpi_name) {
 430     module_name.append("%s", info->dlpi_name);
 431   }
 432   if (module_name[0] == '\0')
 433     return 0;
 434   if (data->filter && !data->filter(module_name.data()))
 435     return 0;
 436   LoadedModule *cur_module = &data->modules[data->current_n];
 437   cur_module->set(module_name.data(), info->dlpi_addr);
 438   data->current_n++;
 439   for (int i = 0; i < info->dlpi_phnum; i++) {
 440     const Elf_Phdr *phdr = &info->dlpi_phdr[i];
 441     if (phdr->p_type == PT_LOAD) {
 442       uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
 443       uptr cur_end = cur_beg + phdr->p_memsz;
 444       bool executable = phdr->p_flags & PF_X;
 445       cur_module->addAddressRange(cur_beg, cur_end, executable);
 446     }
 447   }
 448   return 0;
 449 }
 450
 451 #if SANITIZER_ANDROID && __ANDROID_API__ < 21
 452 extern "C" __attribute__((weak)) int dl_iterate_phdr(
 453     int (*)(struct dl_phdr_info *, size_t, void *), void *);
 454 #endif
 455
 456 uptr GetListOfModules(LoadedModule *modules, uptr max_modules,
 457                       string_predicate_t filter) {
 458 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22
 459   u32 api_level = AndroidGetApiLevel();
 460   // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken.
 461   // The runtime check allows the same library to work with
 462   // both K and L (and future) Android releases.
 463   if (api_level <= ANDROID_LOLLIPOP_MR1) { // L or earlier
 464     MemoryMappingLayout memory_mapping(false);
 465     return memory_mapping.DumpListOfModules(modules, max_modules, filter);
 466   }
 467 #endif
 468   CHECK(modules);
 469   DlIteratePhdrData data = {modules, 0, true, max_modules, filter};
 470   dl_iterate_phdr(dl_iterate_phdr_cb, &data);
 471   return data.current_n;
 472 }
 473
 474 // getrusage does not give us the current RSS, only the max RSS.
 475 // Still, this is better than nothing if /proc/self/statm is not available
 476 // for some reason, e.g. due to a sandbox.
 477 static uptr GetRSSFromGetrusage() {
 478   struct rusage usage;
 479   if (getrusage(RUSAGE_SELF, &usage))  // Failed, probably due to a sandbox.
 480     return 0;
 481   return usage.ru_maxrss << 10;  // ru_maxrss is in Kb.
 482 }
 483
 484 uptr GetRSS() {
 485   if (!common_flags()->can_use_proc_maps_statm)
 486     return GetRSSFromGetrusage();
 487   fd_t fd = OpenFile("/proc/self/statm", RdOnly);
 488   if (fd == kInvalidFd)
 489     return GetRSSFromGetrusage();
 490   char buf[64];
 491   uptr len = internal_read(fd, buf, sizeof(buf) - 1);
 492   internal_close(fd);
 493   if ((sptr)len <= 0)
 494     return 0;
 495   buf[len] = 0;
 496   // The format of the file is:
 497   // 1084 89 69 11 0 79 0
 498   // We need the second number which is RSS in pages.
 499   char *pos = buf;
 500   // Skip the first number.
 501   while (*pos >= '0' && *pos <= '9')
 502     pos++;
 503   // Skip whitespaces.
 504   while (!(*pos >= '0' && *pos <= '9') && *pos != 0)
 505     pos++;
 506   // Read the number.
 507   uptr rss = 0;
 508   while (*pos >= '0' && *pos <= '9')
 509     rss = rss * 10 + *pos++ - '0';
 510   return rss * GetPageSizeCached();
 511 }
 512
 513 // 64-bit Android targets don't provide the deprecated __android_log_write.
 514 // Starting with the L release, syslog() works and is preferable to
 515 // __android_log_write.
 516 #if SANITIZER_LINUX
 517
 518 #if SANITIZER_ANDROID
 519 static atomic_uint8_t android_log_initialized;
 520
 521 void AndroidLogInit() {
 522   atomic_store(&android_log_initialized, 1, memory_order_release);
 523 }
 524
 525 static bool IsSyslogAvailable() {
 526   return atomic_load(&android_log_initialized, memory_order_acquire);
 527 }
 528 #else
 529 void AndroidLogInit() {}
 530
 531 static bool IsSyslogAvailable() { return true; }
 532 #endif  // SANITIZER_ANDROID
 533
 534 static void WriteOneLineToSyslog(const char *s) {
 535 #if SANITIZER_ANDROID &&__ANDROID_API__ < 21
 536   __android_log_write(ANDROID_LOG_INFO, NULL, s);
 537 #else
 538   syslog(LOG_INFO, "%s", s);
 539 #endif
 540 }
 541
 542 void WriteToSyslog(const char *buffer) {
 543   if (!IsSyslogAvailable())
 544     return;
 545   char *copy = internal_strdup(buffer);
 546   char *p = copy;
 547   char *q;
 548   // syslog, at least on Android, has an implicit message length limit.
 549   // Print one line at a time.
 550   do {
 551     q = internal_strchr(p, '\n');
 552     if (q)
 553       *q = '\0';
 554     WriteOneLineToSyslog(p);
 555     if (q)
 556       p = q + 1;
 557   } while (q);
 558   InternalFree(copy);
 559 }
 560 #endif // SANITIZER_LINUX
 561
 562 } // namespace __sanitizer
 563
 564 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX