1 //===-- sanitizer_linux_libcdep.cc ----------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file is shared between AddressSanitizer and ThreadSanitizer 11 // run-time libraries and implements linux-specific functions from 12 // sanitizer_libc.h. 13 //===----------------------------------------------------------------------===// 14 15 #include "sanitizer_platform.h" 16 17 #if SANITIZER_FREEBSD || SANITIZER_LINUX 18 19 #include "sanitizer_allocator_internal.h" 20 #include "sanitizer_atomic.h" 21 #include "sanitizer_common.h" 22 #include "sanitizer_flags.h" 23 #include "sanitizer_freebsd.h" 24 #include "sanitizer_linux.h" 25 #include "sanitizer_placement_new.h" 26 #include "sanitizer_procmaps.h" 27 #include "sanitizer_stacktrace.h" 28 29 #if SANITIZER_ANDROID || SANITIZER_FREEBSD 30 #include <dlfcn.h> // for dlsym() 31 #endif 32 33 #include <link.h> 34 #include <pthread.h> 35 #include <signal.h> 36 #include <sys/resource.h> 37 38 #if SANITIZER_FREEBSD 39 #include <pthread_np.h> 40 #include <osreldate.h> 41 #define pthread_getattr_np pthread_attr_get_np 42 #endif 43 44 #if SANITIZER_LINUX 45 #include <sys/prctl.h> 46 #endif 47 48 #if SANITIZER_ANDROID 49 #include <android/api-level.h> 50 #endif 51 52 #if SANITIZER_ANDROID && __ANDROID_API__ < 21 53 #include <android/log.h> 54 #else 55 #include <syslog.h> 56 #endif 57 58 #if !SANITIZER_ANDROID 59 #include <elf.h> 60 #include <unistd.h> 61 #endif 62 63 namespace __sanitizer { 64 65 SANITIZER_WEAK_ATTRIBUTE int 66 real_sigaction(int signum, const void *act, void *oldact); 67 68 int internal_sigaction(int signum, const void *act, void *oldact) { 69 #if !SANITIZER_GO 70 if (&real_sigaction) 71 return real_sigaction(signum, act, oldact); 72 #endif 73 return sigaction(signum, (const struct sigaction *)act, 74 (struct sigaction *)oldact); 75 } 76 77 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top, 78 uptr *stack_bottom) { 79 CHECK(stack_top); 80 CHECK(stack_bottom); 81 if (at_initialization) { 82 // This is the main thread. Libpthread may not be initialized yet. 83 struct rlimit rl; 84 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0); 85 86 // Find the mapping that contains a stack variable. 87 MemoryMappingLayout proc_maps(/*cache_enabled*/true); 88 uptr start, end, offset; 89 uptr prev_end = 0; 90 while (proc_maps.Next(&start, &end, &offset, nullptr, 0, 91 /* protection */nullptr)) { 92 if ((uptr)&rl < end) 93 break; 94 prev_end = end; 95 } 96 CHECK((uptr)&rl >= start && (uptr)&rl < end); 97 98 // Get stacksize from rlimit, but clip it so that it does not overlap 99 // with other mappings. 100 uptr stacksize = rl.rlim_cur; 101 if (stacksize > end - prev_end) 102 stacksize = end - prev_end; 103 // When running with unlimited stack size, we still want to set some limit. 104 // The unlimited stack size is caused by 'ulimit -s unlimited'. 105 // Also, for some reason, GNU make spawns subprocesses with unlimited stack. 106 if (stacksize > kMaxThreadStackSize) 107 stacksize = kMaxThreadStackSize; 108 *stack_top = end; 109 *stack_bottom = end - stacksize; 110 return; 111 } 112 pthread_attr_t attr; 113 pthread_attr_init(&attr); 114 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0); 115 uptr stacksize = 0; 116 void *stackaddr = nullptr; 117 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize); 118 pthread_attr_destroy(&attr); 119 120 CHECK_LE(stacksize, kMaxThreadStackSize); // Sanity check. 121 *stack_top = (uptr)stackaddr + stacksize; 122 *stack_bottom = (uptr)stackaddr; 123 } 124 125 #if !SANITIZER_GO 126 bool SetEnv(const char *name, const char *value) { 127 void *f = dlsym(RTLD_NEXT, "setenv"); 128 if (!f) 129 return false; 130 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite); 131 setenv_ft setenv_f; 132 CHECK_EQ(sizeof(setenv_f), sizeof(f)); 133 internal_memcpy(&setenv_f, &f, sizeof(f)); 134 return setenv_f(name, value, 1) == 0; 135 } 136 #endif 137 138 bool SanitizerSetThreadName(const char *name) { 139 #ifdef PR_SET_NAME 140 return 0 == prctl(PR_SET_NAME, (unsigned long)name, 0, 0, 0); // NOLINT 141 #else 142 return false; 143 #endif 144 } 145 146 bool SanitizerGetThreadName(char *name, int max_len) { 147 #ifdef PR_GET_NAME 148 char buff[17]; 149 if (prctl(PR_GET_NAME, (unsigned long)buff, 0, 0, 0)) // NOLINT 150 return false; 151 internal_strncpy(name, buff, max_len); 152 name[max_len] = 0; 153 return true; 154 #else 155 return false; 156 #endif 157 } 158 159 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO 160 static uptr g_tls_size; 161 162 #ifdef __i386__ 163 # define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall)) 164 #else 165 # define DL_INTERNAL_FUNCTION 166 #endif 167 168 void InitTlsSize() { 169 // all current supported platforms have 16 bytes stack alignment 170 const size_t kStackAlign = 16; 171 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION; 172 get_tls_func get_tls; 173 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); 174 CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr)); 175 internal_memcpy(&get_tls, &get_tls_static_info_ptr, 176 sizeof(get_tls_static_info_ptr)); 177 CHECK_NE(get_tls, 0); 178 size_t tls_size = 0; 179 size_t tls_align = 0; 180 get_tls(&tls_size, &tls_align); 181 if (tls_align < kStackAlign) 182 tls_align = kStackAlign; 183 g_tls_size = RoundUpTo(tls_size, tls_align); 184 } 185 #else 186 void InitTlsSize() { } 187 #endif // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO 188 189 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) \ 190 || defined(__aarch64__) || defined(__powerpc64__) || defined(__s390__)) \ 191 && SANITIZER_LINUX && !SANITIZER_ANDROID 192 // sizeof(struct pthread) from glibc. 193 static atomic_uintptr_t kThreadDescriptorSize; 194 195 uptr ThreadDescriptorSize() { 196 uptr val = atomic_load(&kThreadDescriptorSize, memory_order_relaxed); 197 if (val) 198 return val; 199 #if defined(__x86_64__) || defined(__i386__) 200 #ifdef _CS_GNU_LIBC_VERSION 201 char buf[64]; 202 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf)); 203 if (len < sizeof(buf) && internal_strncmp(buf, "glibc 2.", 8) == 0) { 204 char *end; 205 int minor = internal_simple_strtoll(buf + 8, &end, 10); 206 if (end != buf + 8 && (*end == '\0' || *end == '.')) { 207 int patch = 0; 208 if (*end == '.') 209 // strtoll will return 0 if no valid conversion could be performed 210 patch = internal_simple_strtoll(end + 1, nullptr, 10); 211 212 /* sizeof(struct pthread) values from various glibc versions. */ 213 if (SANITIZER_X32) 214 val = 1728; // Assume only one particular version for x32. 215 else if (minor <= 3) 216 val = FIRST_32_SECOND_64(1104, 1696); 217 else if (minor == 4) 218 val = FIRST_32_SECOND_64(1120, 1728); 219 else if (minor == 5) 220 val = FIRST_32_SECOND_64(1136, 1728); 221 else if (minor <= 9) 222 val = FIRST_32_SECOND_64(1136, 1712); 223 else if (minor == 10) 224 val = FIRST_32_SECOND_64(1168, 1776); 225 else if (minor == 11 || (minor == 12 && patch == 1)) 226 val = FIRST_32_SECOND_64(1168, 2288); 227 else if (minor <= 13) 228 val = FIRST_32_SECOND_64(1168, 2304); 229 else 230 val = FIRST_32_SECOND_64(1216, 2304); 231 } 232 if (val) 233 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed); 234 return val; 235 } 236 #endif 237 #elif defined(__mips__) 238 // TODO(sagarthakur): add more values as per different glibc versions. 239 val = FIRST_32_SECOND_64(1152, 1776); 240 if (val) 241 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed); 242 return val; 243 #elif defined(__aarch64__) 244 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22. 245 val = 1776; 246 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed); 247 return val; 248 #elif defined(__powerpc64__) 249 val = 1776; // from glibc.ppc64le 2.20-8.fc21 250 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed); 251 return val; 252 #elif defined(__s390__) 253 val = FIRST_32_SECOND_64(1152, 1776); // valid for glibc 2.22 254 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed); 255 #endif 256 return 0; 257 } 258 259 // The offset at which pointer to self is located in the thread descriptor. 260 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16); 261 262 uptr ThreadSelfOffset() { 263 return kThreadSelfOffset; 264 } 265 266 #if defined(__mips__) || defined(__powerpc64__) 267 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb 268 // head structure. It lies before the static tls blocks. 269 static uptr TlsPreTcbSize() { 270 # if defined(__mips__) 271 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 272 # elif defined(__powerpc64__) 273 const uptr kTcbHead = 88; // sizeof (tcbhead_t) 274 # endif 275 const uptr kTlsAlign = 16; 276 const uptr kTlsPreTcbSize = 277 (ThreadDescriptorSize() + kTcbHead + kTlsAlign - 1) & ~(kTlsAlign - 1); 278 InitTlsSize(); 279 g_tls_size = (g_tls_size + kTlsPreTcbSize + kTlsAlign -1) & ~(kTlsAlign - 1); 280 return kTlsPreTcbSize; 281 } 282 #endif 283 284 uptr ThreadSelf() { 285 uptr descr_addr; 286 # if defined(__i386__) 287 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 288 # elif defined(__x86_64__) 289 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 290 # elif defined(__mips__) 291 // MIPS uses TLS variant I. The thread pointer (in hardware register $29) 292 // points to the end of the TCB + 0x7000. The pthread_descr structure is 293 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 294 // TCB and the size of pthread_descr. 295 const uptr kTlsTcbOffset = 0x7000; 296 uptr thread_pointer; 297 asm volatile(".set push;\ 298 .set mips64r2;\ 299 rdhwr %0,$29;\ 300 .set pop" : "=r" (thread_pointer)); 301 descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize(); 302 # elif defined(__aarch64__) || 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 atomic_store(&android_log_initialized, 1, memory_order_release); 525 } 526 527 static bool ShouldLogAfterPrintf() { 528 return atomic_load(&android_log_initialized, memory_order_acquire); 529 } 530 #else 531 void AndroidLogInit() {} 532 533 static bool ShouldLogAfterPrintf() { return true; } 534 #endif // SANITIZER_ANDROID 535 536 void WriteOneLineToSyslog(const char *s) { 537 #if SANITIZER_ANDROID &&__ANDROID_API__ < 21 538 __android_log_write(ANDROID_LOG_INFO, NULL, s); 539 #else 540 syslog(LOG_INFO, "%s", s); 541 #endif 542 } 543 544 void LogMessageOnPrintf(const char *str) { 545 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf()) 546 WriteToSyslog(str); 547 } 548 549 #endif // SANITIZER_LINUX 550 551 } // namespace __sanitizer 552 553 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX 554
