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 #endif 162 163 #ifdef __i386__ 164 # define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall)) 165 #else 166 # define DL_INTERNAL_FUNCTION 167 #endif 168 169 #if defined(__mips__) || defined(__powerpc64__) 170 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb 171 // head structure. It lies before the static tls blocks. 172 static uptr TlsPreTcbSize() { 173 # if defined(__mips__) 174 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 175 # elif defined(__powerpc64__) 176 const uptr kTcbHead = 88; // sizeof (tcbhead_t) 177 # endif 178 const uptr kTlsAlign = 16; 179 const uptr kTlsPreTcbSize = 180 (ThreadDescriptorSize() + kTcbHead + kTlsAlign - 1) & ~(kTlsAlign - 1); 181 InitTlsSize(); 182 g_tls_size = (g_tls_size + kTlsPreTcbSize + kTlsAlign -1) & ~(kTlsAlign - 1); 183 return kTlsPreTcbSize; 184 } 185 #endif 186 187 void InitTlsSize() { 188 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO 189 // all current supported platforms have 16 bytes stack alignment 190 const size_t kStackAlign = 16; 191 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION; 192 get_tls_func get_tls; 193 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); 194 CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr)); 195 internal_memcpy(&get_tls, &get_tls_static_info_ptr, 196 sizeof(get_tls_static_info_ptr)); 197 CHECK_NE(get_tls, 0); 198 size_t tls_size = 0; 199 size_t tls_align = 0; 200 get_tls(&tls_size, &tls_align); 201 if (tls_align < kStackAlign) 202 tls_align = kStackAlign; 203 g_tls_size = RoundUpTo(tls_size, tls_align); 204 #endif // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO 205 } 206 207 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) \ 208 || defined(__aarch64__) || defined(__powerpc64__)) \ 209 && SANITIZER_LINUX && !SANITIZER_ANDROID 210 // sizeof(struct pthread) from glibc. 211 static atomic_uintptr_t kThreadDescriptorSize; 212 213 uptr ThreadDescriptorSize() { 214 uptr val = atomic_load(&kThreadDescriptorSize, memory_order_relaxed); 215 if (val) 216 return val; 217 #if defined(__x86_64__) || defined(__i386__) 218 #ifdef _CS_GNU_LIBC_VERSION 219 char buf[64]; 220 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf)); 221 if (len < sizeof(buf) && internal_strncmp(buf, "glibc 2.", 8) == 0) { 222 char *end; 223 int minor = internal_simple_strtoll(buf + 8, &end, 10); 224 if (end != buf + 8 && (*end == '\0' || *end == '.')) { 225 /* sizeof(struct pthread) values from various glibc versions. */ 226 if (SANITIZER_X32) 227 val = 1728; // Assume only one particular version for x32. 228 else if (minor <= 3) 229 val = FIRST_32_SECOND_64(1104, 1696); 230 else if (minor == 4) 231 val = FIRST_32_SECOND_64(1120, 1728); 232 else if (minor == 5) 233 val = FIRST_32_SECOND_64(1136, 1728); 234 else if (minor <= 9) 235 val = FIRST_32_SECOND_64(1136, 1712); 236 else if (minor == 10) 237 val = FIRST_32_SECOND_64(1168, 1776); 238 else if (minor <= 12) 239 val = FIRST_32_SECOND_64(1168, 2288); 240 else if (minor == 13) 241 val = FIRST_32_SECOND_64(1168, 2304); 242 else 243 val = FIRST_32_SECOND_64(1216, 2304); 244 } 245 if (val) 246 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed); 247 return val; 248 } 249 #endif 250 #elif defined(__mips__) 251 // TODO(sagarthakur): add more values as per different glibc versions. 252 val = FIRST_32_SECOND_64(1152, 1776); 253 if (val) 254 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed); 255 return val; 256 #elif defined(__aarch64__) 257 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22. 258 val = 1776; 259 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed); 260 return val; 261 #elif defined(__powerpc64__) 262 val = 1776; // from glibc.ppc64le 2.20-8.fc21 263 atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed); 264 return val; 265 #endif 266 return 0; 267 } 268 269 // The offset at which pointer to self is located in the thread descriptor. 270 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16); 271 272 uptr ThreadSelfOffset() { 273 return kThreadSelfOffset; 274 } 275 276 uptr ThreadSelf() { 277 uptr descr_addr; 278 # if defined(__i386__) 279 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 280 # elif defined(__x86_64__) 281 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 282 # elif defined(__mips__) 283 // MIPS uses TLS variant I. The thread pointer (in hardware register $29) 284 // points to the end of the TCB + 0x7000. The pthread_descr structure is 285 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 286 // TCB and the size of pthread_descr. 287 const uptr kTlsTcbOffset = 0x7000; 288 uptr thread_pointer; 289 asm volatile(".set push;\ 290 .set mips64r2;\ 291 rdhwr %0,$29;\ 292 .set pop" : "=r" (thread_pointer)); 293 descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize(); 294 # elif defined(__aarch64__) 295 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()); 296 # elif defined(__powerpc64__) 297 // PPC64LE uses TLS variant I. The thread pointer (in GPR 13) 298 // points to the end of the TCB + 0x7000. The pthread_descr structure is 299 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 300 // TCB and the size of pthread_descr. 301 const uptr kTlsTcbOffset = 0x7000; 302 uptr thread_pointer; 303 asm("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset)); 304 descr_addr = thread_pointer - TlsPreTcbSize(); 305 # else 306 # error "unsupported CPU arch" 307 # endif 308 return descr_addr; 309 } 310 #endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX 311 312 #if SANITIZER_FREEBSD 313 static void **ThreadSelfSegbase() { 314 void **segbase = 0; 315 # if defined(__i386__) 316 // sysarch(I386_GET_GSBASE, segbase); 317 __asm __volatile("mov %%gs:0, %0" : "=r" (segbase)); 318 # elif defined(__x86_64__) 319 // sysarch(AMD64_GET_FSBASE, segbase); 320 __asm __volatile("movq %%fs:0, %0" : "=r" (segbase)); 321 # else 322 # error "unsupported CPU arch for FreeBSD platform" 323 # endif 324 return segbase; 325 } 326 327 uptr ThreadSelf() { 328 return (uptr)ThreadSelfSegbase()[2]; 329 } 330 #endif // SANITIZER_FREEBSD 331 332 #if !SANITIZER_GO 333 static void GetTls(uptr *addr, uptr *size) { 334 #if SANITIZER_LINUX && !SANITIZER_ANDROID 335 # if defined(__x86_64__) || defined(__i386__) 336 *addr = ThreadSelf(); 337 *size = GetTlsSize(); 338 *addr -= *size; 339 *addr += ThreadDescriptorSize(); 340 # elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__) 341 *addr = ThreadSelf(); 342 *size = GetTlsSize(); 343 # else 344 *addr = 0; 345 *size = 0; 346 # endif 347 #elif SANITIZER_FREEBSD 348 void** segbase = ThreadSelfSegbase(); 349 *addr = 0; 350 *size = 0; 351 if (segbase != 0) { 352 // tcbalign = 16 353 // tls_size = round(tls_static_space, tcbalign); 354 // dtv = segbase[1]; 355 // dtv[2] = segbase - tls_static_space; 356 void **dtv = (void**) segbase[1]; 357 *addr = (uptr) dtv[2]; 358 *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]); 359 } 360 #elif SANITIZER_ANDROID 361 *addr = 0; 362 *size = 0; 363 #else 364 # error "Unknown OS" 365 #endif 366 } 367 #endif 368 369 #if !SANITIZER_GO 370 uptr GetTlsSize() { 371 #if SANITIZER_FREEBSD || SANITIZER_ANDROID 372 uptr addr, size; 373 GetTls(&addr, &size); 374 return size; 375 #else 376 return g_tls_size; 377 #endif 378 } 379 #endif 380 381 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, 382 uptr *tls_addr, uptr *tls_size) { 383 #if SANITIZER_GO 384 // Stub implementation for Go. 385 *stk_addr = *stk_size = *tls_addr = *tls_size = 0; 386 #else 387 GetTls(tls_addr, tls_size); 388 389 uptr stack_top, stack_bottom; 390 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); 391 *stk_addr = stack_bottom; 392 *stk_size = stack_top - stack_bottom; 393 394 if (!main) { 395 // If stack and tls intersect, make them non-intersecting. 396 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { 397 CHECK_GT(*tls_addr + *tls_size, *stk_addr); 398 CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size); 399 *stk_size -= *tls_size; 400 *tls_addr = *stk_addr + *stk_size; 401 } 402 } 403 #endif 404 } 405 406 # if !SANITIZER_FREEBSD 407 typedef ElfW(Phdr) Elf_Phdr; 408 # elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2 409 # define Elf_Phdr XElf32_Phdr 410 # define dl_phdr_info xdl_phdr_info 411 # define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b)) 412 # endif 413 414 struct DlIteratePhdrData { 415 LoadedModule *modules; 416 uptr current_n; 417 bool first; 418 uptr max_n; 419 string_predicate_t filter; 420 }; 421 422 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) { 423 DlIteratePhdrData *data = (DlIteratePhdrData*)arg; 424 if (data->current_n == data->max_n) 425 return 0; 426 InternalScopedString module_name(kMaxPathLength); 427 if (data->first) { 428 data->first = false; 429 // First module is the binary itself. 430 ReadBinaryNameCached(module_name.data(), module_name.size()); 431 } else if (info->dlpi_name) { 432 module_name.append("%s", info->dlpi_name); 433 } 434 if (module_name[0] == '\0') 435 return 0; 436 if (data->filter && !data->filter(module_name.data())) 437 return 0; 438 LoadedModule *cur_module = &data->modules[data->current_n]; 439 cur_module->set(module_name.data(), info->dlpi_addr); 440 data->current_n++; 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 return 0; 451 } 452 453 #if SANITIZER_ANDROID && __ANDROID_API__ < 21 454 extern "C" __attribute__((weak)) int dl_iterate_phdr( 455 int (*)(struct dl_phdr_info *, size_t, void *), void *); 456 #endif 457 458 uptr GetListOfModules(LoadedModule *modules, uptr max_modules, 459 string_predicate_t filter) { 460 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22 461 u32 api_level = AndroidGetApiLevel(); 462 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken. 463 // The runtime check allows the same library to work with 464 // both K and L (and future) Android releases. 465 if (api_level <= ANDROID_LOLLIPOP_MR1) { // L or earlier 466 MemoryMappingLayout memory_mapping(false); 467 return memory_mapping.DumpListOfModules(modules, max_modules, filter); 468 } 469 #endif 470 CHECK(modules); 471 DlIteratePhdrData data = {modules, 0, true, max_modules, filter}; 472 dl_iterate_phdr(dl_iterate_phdr_cb, &data); 473 return data.current_n; 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 bool ShouldLogAfterPrintf() { 528 return atomic_load(&android_log_initialized, memory_order_acquire); 529 } 530 #else 531 void AndroidLogInit() {} 532 533 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 #endif // SANITIZER_LINUX 545 546 } // namespace __sanitizer 547 548 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX 549
