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 || SANITIZER_NETBSD || \ 16 SANITIZER_OPENBSD || SANITIZER_SOLARIS 17 18 #include "sanitizer_allocator_internal.h" 19 #include "sanitizer_atomic.h" 20 #include "sanitizer_common.h" 21 #include "sanitizer_file.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 28 #if SANITIZER_NETBSD 29 #define _RTLD_SOURCE // for __lwp_gettcb_fast() / __lwp_getprivate_fast() 30 #endif 31 32 #include <dlfcn.h> // for dlsym() 33 #include <link.h> 34 #include <pthread.h> 35 #include <signal.h> 36 #include <sys/resource.h> 37 #include <syslog.h> 38 39 #if SANITIZER_FREEBSD 40 #include <pthread_np.h> 41 #include <osreldate.h> 42 #include <sys/sysctl.h> 43 #define pthread_getattr_np pthread_attr_get_np 44 #endif 45 46 #if SANITIZER_OPENBSD 47 #include <pthread_np.h> 48 #include <sys/sysctl.h> 49 #endif 50 51 #if SANITIZER_NETBSD 52 #include <sys/sysctl.h> 53 #include <sys/tls.h> 54 #include <lwp.h> 55 #endif 56 57 #if SANITIZER_SOLARIS 58 #include <thread.h> 59 #endif 60 61 #if SANITIZER_ANDROID 62 #include <android/api-level.h> 63 #if !defined(CPU_COUNT) && !defined(__aarch64__) 64 #include <dirent.h> 65 #include <fcntl.h> 66 struct __sanitizer::linux_dirent { 67 long d_ino; 68 off_t d_off; 69 unsigned short d_reclen; 70 char d_name[]; 71 }; 72 #endif 73 #endif 74 75 #if !SANITIZER_ANDROID 76 #include <elf.h> 77 #include <unistd.h> 78 #endif 79 80 #if SANITIZER_NETBSD 81 #include <machine/mcontext.h> 82 #endif 83 84 namespace __sanitizer { 85 86 SANITIZER_WEAK_ATTRIBUTE int 87 real_sigaction(int signum, const void *act, void *oldact); 88 89 int internal_sigaction(int signum, const void *act, void *oldact) { 90 #if !SANITIZER_GO 91 if (&real_sigaction) 92 return real_sigaction(signum, act, oldact); 93 #endif 94 return sigaction(signum, (const struct sigaction *)act, 95 (struct sigaction *)oldact); 96 } 97 98 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top, 99 uptr *stack_bottom) { 100 CHECK(stack_top); 101 CHECK(stack_bottom); 102 if (at_initialization) { 103 // This is the main thread. Libpthread may not be initialized yet. 104 struct rlimit rl; 105 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0); 106 107 // Find the mapping that contains a stack variable. 108 MemoryMappingLayout proc_maps(/*cache_enabled*/true); 109 MemoryMappedSegment segment; 110 uptr prev_end = 0; 111 while (proc_maps.Next(&segment)) { 112 if ((uptr)&rl < segment.end) break; 113 prev_end = segment.end; 114 } 115 CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end); 116 117 // Get stacksize from rlimit, but clip it so that it does not overlap 118 // with other mappings. 119 uptr stacksize = rl.rlim_cur; 120 if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end; 121 // When running with unlimited stack size, we still want to set some limit. 122 // The unlimited stack size is caused by 'ulimit -s unlimited'. 123 // Also, for some reason, GNU make spawns subprocesses with unlimited stack. 124 if (stacksize > kMaxThreadStackSize) 125 stacksize = kMaxThreadStackSize; 126 *stack_top = segment.end; 127 *stack_bottom = segment.end - stacksize; 128 return; 129 } 130 uptr stacksize = 0; 131 void *stackaddr = nullptr; 132 #if SANITIZER_SOLARIS 133 stack_t ss; 134 CHECK_EQ(thr_stksegment(&ss), 0); 135 stacksize = ss.ss_size; 136 stackaddr = (char *)ss.ss_sp - stacksize; 137 #elif SANITIZER_OPENBSD 138 stack_t sattr; 139 CHECK_EQ(pthread_stackseg_np(pthread_self(), &sattr), 0); 140 stackaddr = sattr.ss_sp; 141 stacksize = sattr.ss_size; 142 #else // !SANITIZER_SOLARIS 143 pthread_attr_t attr; 144 pthread_attr_init(&attr); 145 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0); 146 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize); 147 pthread_attr_destroy(&attr); 148 #endif // SANITIZER_SOLARIS 149 150 *stack_top = (uptr)stackaddr + stacksize; 151 *stack_bottom = (uptr)stackaddr; 152 } 153 154 #if !SANITIZER_GO 155 bool SetEnv(const char *name, const char *value) { 156 void *f = dlsym(RTLD_NEXT, "setenv"); 157 if (!f) 158 return false; 159 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite); 160 setenv_ft setenv_f; 161 CHECK_EQ(sizeof(setenv_f), sizeof(f)); 162 internal_memcpy(&setenv_f, &f, sizeof(f)); 163 return setenv_f(name, value, 1) == 0; 164 } 165 #endif 166 167 __attribute__((unused)) static bool GetLibcVersion(int *major, int *minor, 168 int *patch) { 169 #ifdef _CS_GNU_LIBC_VERSION 170 char buf[64]; 171 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf)); 172 if (len >= sizeof(buf)) 173 return false; 174 buf[len] = 0; 175 static const char kGLibC[] = "glibc "; 176 if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0) 177 return false; 178 const char *p = buf + sizeof(kGLibC) - 1; 179 *major = internal_simple_strtoll(p, &p, 10); 180 *minor = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 181 *patch = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 182 return true; 183 #else 184 return false; 185 #endif 186 } 187 188 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO && \ 189 !SANITIZER_NETBSD && !SANITIZER_OPENBSD && !SANITIZER_SOLARIS 190 static uptr g_tls_size; 191 192 #ifdef __i386__ 193 # ifndef __GLIBC_PREREQ 194 # define CHECK_GET_TLS_STATIC_INFO_VERSION 1 195 # else 196 # define CHECK_GET_TLS_STATIC_INFO_VERSION (!__GLIBC_PREREQ(2, 27)) 197 # endif 198 #else 199 # define CHECK_GET_TLS_STATIC_INFO_VERSION 0 200 #endif 201 202 #if CHECK_GET_TLS_STATIC_INFO_VERSION 203 # define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall)) 204 #else 205 # define DL_INTERNAL_FUNCTION 206 #endif 207 208 namespace { 209 struct GetTlsStaticInfoCall { 210 typedef void (*get_tls_func)(size_t*, size_t*); 211 }; 212 struct GetTlsStaticInfoRegparmCall { 213 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION; 214 }; 215 216 template <typename T> 217 void CallGetTls(void* ptr, size_t* size, size_t* align) { 218 typename T::get_tls_func get_tls; 219 CHECK_EQ(sizeof(get_tls), sizeof(ptr)); 220 internal_memcpy(&get_tls, &ptr, sizeof(ptr)); 221 CHECK_NE(get_tls, 0); 222 get_tls(size, align); 223 } 224 225 bool CmpLibcVersion(int major, int minor, int patch) { 226 int ma; 227 int mi; 228 int pa; 229 if (!GetLibcVersion(&ma, &mi, &pa)) 230 return false; 231 if (ma > major) 232 return true; 233 if (ma < major) 234 return false; 235 if (mi > minor) 236 return true; 237 if (mi < minor) 238 return false; 239 return pa >= patch; 240 } 241 242 } // namespace 243 244 #if defined(__mips__) || defined(__powerpc64__) 245 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb 246 // head structure. It lies before the static tls blocks. 247 static uptr TlsPreTcbSize() { 248 # if defined(__mips__) 249 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 250 # elif defined(__powerpc64__) 251 const uptr kTcbHead = 88; // sizeof (tcbhead_t) 252 # endif 253 const uptr kTlsAlign = 16; 254 const uptr kTlsPreTcbSize = 255 (ThreadDescriptorSize() + kTcbHead + kTlsAlign - 1) & ~(kTlsAlign - 1); 256 InitTlsSize(); 257 g_tls_size = (g_tls_size + kTlsPreTcbSize + kTlsAlign -1) & ~(kTlsAlign - 1); 258 return kTlsPreTcbSize; 259 } 260 #endif 261 262 void InitTlsSize() { 263 // all current supported platforms have 16 bytes stack alignment 264 const size_t kStackAlign = 16; 265 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); 266 size_t tls_size = 0; 267 size_t tls_align = 0; 268 // On i?86, _dl_get_tls_static_info used to be internal_function, i.e. 269 // __attribute__((regparm(3), stdcall)) before glibc 2.27 and is normal 270 // function in 2.27 and later. 271 if (CHECK_GET_TLS_STATIC_INFO_VERSION && !CmpLibcVersion(2, 27, 0)) 272 CallGetTls<GetTlsStaticInfoRegparmCall>(get_tls_static_info_ptr, 273 &tls_size, &tls_align); 274 else 275 CallGetTls<GetTlsStaticInfoCall>(get_tls_static_info_ptr, 276 &tls_size, &tls_align); 277 if (tls_align < kStackAlign) 278 tls_align = kStackAlign; 279 g_tls_size = RoundUpTo(tls_size, tls_align); 280 } 281 #else 282 void InitTlsSize() { } 283 #endif // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO && 284 // !SANITIZER_NETBSD && !SANITIZER_SOLARIS 285 286 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) || \ 287 defined(__aarch64__) || defined(__powerpc64__) || defined(__s390__) || \ 288 defined(__arm__)) && \ 289 SANITIZER_LINUX && !SANITIZER_ANDROID 290 // sizeof(struct pthread) from glibc. 291 static atomic_uintptr_t thread_descriptor_size; 292 293 uptr ThreadDescriptorSize() { 294 uptr val = atomic_load_relaxed(&thread_descriptor_size); 295 if (val) 296 return val; 297 #if defined(__x86_64__) || defined(__i386__) || defined(__arm__) 298 int major; 299 int minor; 300 int patch; 301 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 302 /* sizeof(struct pthread) values from various glibc versions. */ 303 if (SANITIZER_X32) 304 val = 1728; // Assume only one particular version for x32. 305 // For ARM sizeof(struct pthread) changed in Glibc 2.23. 306 else if (SANITIZER_ARM) 307 val = minor <= 22 ? 1120 : 1216; 308 else if (minor <= 3) 309 val = FIRST_32_SECOND_64(1104, 1696); 310 else if (minor == 4) 311 val = FIRST_32_SECOND_64(1120, 1728); 312 else if (minor == 5) 313 val = FIRST_32_SECOND_64(1136, 1728); 314 else if (minor <= 9) 315 val = FIRST_32_SECOND_64(1136, 1712); 316 else if (minor == 10) 317 val = FIRST_32_SECOND_64(1168, 1776); 318 else if (minor == 11 || (minor == 12 && patch == 1)) 319 val = FIRST_32_SECOND_64(1168, 2288); 320 else if (minor <= 14) 321 val = FIRST_32_SECOND_64(1168, 2304); 322 else 323 val = FIRST_32_SECOND_64(1216, 2304); 324 } 325 #elif defined(__mips__) 326 // TODO(sagarthakur): add more values as per different glibc versions. 327 val = FIRST_32_SECOND_64(1152, 1776); 328 #elif defined(__aarch64__) 329 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22. 330 val = 1776; 331 #elif defined(__powerpc64__) 332 val = 1776; // from glibc.ppc64le 2.20-8.fc21 333 #elif defined(__s390__) 334 val = FIRST_32_SECOND_64(1152, 1776); // valid for glibc 2.22 335 #endif 336 if (val) 337 atomic_store_relaxed(&thread_descriptor_size, val); 338 return val; 339 } 340 341 // The offset at which pointer to self is located in the thread descriptor. 342 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16); 343 344 uptr ThreadSelfOffset() { 345 return kThreadSelfOffset; 346 } 347 348 #if defined(__mips__) || defined(__powerpc64__) 349 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb 350 // head structure. It lies before the static tls blocks. 351 static uptr TlsPreTcbSize() { 352 # if defined(__mips__) 353 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 354 # elif defined(__powerpc64__) 355 const uptr kTcbHead = 88; // sizeof (tcbhead_t) 356 # endif 357 const uptr kTlsAlign = 16; 358 const uptr kTlsPreTcbSize = 359 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign); 360 return kTlsPreTcbSize; 361 } 362 #endif 363 364 uptr ThreadSelf() { 365 uptr descr_addr; 366 # if defined(__i386__) 367 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 368 # elif defined(__x86_64__) 369 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 370 # elif defined(__mips__) 371 // MIPS uses TLS variant I. The thread pointer (in hardware register $29) 372 // points to the end of the TCB + 0x7000. The pthread_descr structure is 373 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 374 // TCB and the size of pthread_descr. 375 const uptr kTlsTcbOffset = 0x7000; 376 uptr thread_pointer; 377 asm volatile(".set push;\ 378 .set mips64r2;\ 379 rdhwr %0,$29;\ 380 .set pop" : "=r" (thread_pointer)); 381 descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize(); 382 # elif defined(__aarch64__) || defined(__arm__) 383 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) - 384 ThreadDescriptorSize(); 385 # elif defined(__s390__) 386 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()); 387 # elif defined(__powerpc64__) 388 // PPC64LE uses TLS variant I. The thread pointer (in GPR 13) 389 // points to the end of the TCB + 0x7000. The pthread_descr structure is 390 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 391 // TCB and the size of pthread_descr. 392 const uptr kTlsTcbOffset = 0x7000; 393 uptr thread_pointer; 394 asm("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset)); 395 descr_addr = thread_pointer - TlsPreTcbSize(); 396 # else 397 # error "unsupported CPU arch" 398 # endif 399 return descr_addr; 400 } 401 #endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX 402 403 #if SANITIZER_FREEBSD 404 static void **ThreadSelfSegbase() { 405 void **segbase = 0; 406 # if defined(__i386__) 407 // sysarch(I386_GET_GSBASE, segbase); 408 __asm __volatile("mov %%gs:0, %0" : "=r" (segbase)); 409 # elif defined(__x86_64__) 410 // sysarch(AMD64_GET_FSBASE, segbase); 411 __asm __volatile("movq %%fs:0, %0" : "=r" (segbase)); 412 # else 413 # error "unsupported CPU arch" 414 # endif 415 return segbase; 416 } 417 418 uptr ThreadSelf() { 419 return (uptr)ThreadSelfSegbase()[2]; 420 } 421 #endif // SANITIZER_FREEBSD 422 423 #if SANITIZER_NETBSD 424 static struct tls_tcb * ThreadSelfTlsTcb() { 425 struct tls_tcb *tcb = nullptr; 426 #ifdef __HAVE___LWP_GETTCB_FAST 427 tcb = (struct tls_tcb *)__lwp_gettcb_fast(); 428 #elif defined(__HAVE___LWP_GETPRIVATE_FAST) 429 tcb = (struct tls_tcb *)__lwp_getprivate_fast(); 430 #endif 431 return tcb; 432 } 433 434 uptr ThreadSelf() { 435 return (uptr)ThreadSelfTlsTcb()->tcb_pthread; 436 } 437 438 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) { 439 const Elf_Phdr *hdr = info->dlpi_phdr; 440 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum; 441 442 for (; hdr != last_hdr; ++hdr) { 443 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) { 444 *(uptr*)data = hdr->p_memsz; 445 break; 446 } 447 } 448 return 0; 449 } 450 #endif // SANITIZER_NETBSD 451 452 #if !SANITIZER_GO 453 static void GetTls(uptr *addr, uptr *size) { 454 #if SANITIZER_LINUX && !SANITIZER_ANDROID 455 # if defined(__x86_64__) || defined(__i386__) || defined(__s390__) 456 *addr = ThreadSelf(); 457 *size = GetTlsSize(); 458 *addr -= *size; 459 *addr += ThreadDescriptorSize(); 460 # elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__) \ 461 || defined(__arm__) 462 *addr = ThreadSelf(); 463 *size = GetTlsSize(); 464 # else 465 *addr = 0; 466 *size = 0; 467 # endif 468 #elif SANITIZER_FREEBSD 469 void** segbase = ThreadSelfSegbase(); 470 *addr = 0; 471 *size = 0; 472 if (segbase != 0) { 473 // tcbalign = 16 474 // tls_size = round(tls_static_space, tcbalign); 475 // dtv = segbase[1]; 476 // dtv[2] = segbase - tls_static_space; 477 void **dtv = (void**) segbase[1]; 478 *addr = (uptr) dtv[2]; 479 *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]); 480 } 481 #elif SANITIZER_NETBSD 482 struct tls_tcb * const tcb = ThreadSelfTlsTcb(); 483 *addr = 0; 484 *size = 0; 485 if (tcb != 0) { 486 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program). 487 // ld.elf_so hardcodes the index 1. 488 dl_iterate_phdr(GetSizeFromHdr, size); 489 490 if (*size != 0) { 491 // The block has been found and tcb_dtv[1] contains the base address 492 *addr = (uptr)tcb->tcb_dtv[1]; 493 } 494 } 495 #elif SANITIZER_OPENBSD 496 *addr = 0; 497 *size = 0; 498 #elif SANITIZER_ANDROID 499 *addr = 0; 500 *size = 0; 501 #elif SANITIZER_SOLARIS 502 // FIXME 503 *addr = 0; 504 *size = 0; 505 #else 506 # error "Unknown OS" 507 #endif 508 } 509 #endif 510 511 #if !SANITIZER_GO 512 uptr GetTlsSize() { 513 #if SANITIZER_FREEBSD || SANITIZER_ANDROID || SANITIZER_NETBSD || \ 514 SANITIZER_OPENBSD || SANITIZER_SOLARIS 515 uptr addr, size; 516 GetTls(&addr, &size); 517 return size; 518 #elif defined(__mips__) || defined(__powerpc64__) 519 return RoundUpTo(g_tls_size + TlsPreTcbSize(), 16); 520 #else 521 return g_tls_size; 522 #endif 523 } 524 #endif 525 526 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, 527 uptr *tls_addr, uptr *tls_size) { 528 #if SANITIZER_GO 529 // Stub implementation for Go. 530 *stk_addr = *stk_size = *tls_addr = *tls_size = 0; 531 #else 532 GetTls(tls_addr, tls_size); 533 534 uptr stack_top, stack_bottom; 535 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); 536 *stk_addr = stack_bottom; 537 *stk_size = stack_top - stack_bottom; 538 539 if (!main) { 540 // If stack and tls intersect, make them non-intersecting. 541 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { 542 CHECK_GT(*tls_addr + *tls_size, *stk_addr); 543 CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size); 544 *stk_size -= *tls_size; 545 *tls_addr = *stk_addr + *stk_size; 546 } 547 } 548 #endif 549 } 550 551 #if !SANITIZER_NETBSD 552 #if !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 553 typedef ElfW(Phdr) Elf_Phdr; 554 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2 555 #define Elf_Phdr XElf32_Phdr 556 #define dl_phdr_info xdl_phdr_info 557 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b)) 558 #endif // !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 559 #endif // !SANITIZER_NETBSD 560 561 struct DlIteratePhdrData { 562 InternalMmapVectorNoCtor<LoadedModule> *modules; 563 bool first; 564 }; 565 566 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) { 567 DlIteratePhdrData *data = (DlIteratePhdrData*)arg; 568 InternalScopedString module_name(kMaxPathLength); 569 if (data->first) { 570 data->first = false; 571 // First module is the binary itself. 572 ReadBinaryNameCached(module_name.data(), module_name.size()); 573 } else if (info->dlpi_name) { 574 module_name.append("%s", info->dlpi_name); 575 } 576 if (module_name[0] == '\0') 577 return 0; 578 LoadedModule cur_module; 579 cur_module.set(module_name.data(), info->dlpi_addr); 580 for (int i = 0; i < (int)info->dlpi_phnum; i++) { 581 const Elf_Phdr *phdr = &info->dlpi_phdr[i]; 582 if (phdr->p_type == PT_LOAD) { 583 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr; 584 uptr cur_end = cur_beg + phdr->p_memsz; 585 bool executable = phdr->p_flags & PF_X; 586 bool writable = phdr->p_flags & PF_W; 587 cur_module.addAddressRange(cur_beg, cur_end, executable, 588 writable); 589 } 590 } 591 data->modules->push_back(cur_module); 592 return 0; 593 } 594 595 #if SANITIZER_ANDROID && __ANDROID_API__ < 21 596 extern "C" __attribute__((weak)) int dl_iterate_phdr( 597 int (*)(struct dl_phdr_info *, size_t, void *), void *); 598 #endif 599 600 static bool requiresProcmaps() { 601 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22 602 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken. 603 // The runtime check allows the same library to work with 604 // both K and L (and future) Android releases. 605 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1; 606 #else 607 return false; 608 #endif 609 } 610 611 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) { 612 MemoryMappingLayout memory_mapping(/*cache_enabled*/true); 613 memory_mapping.DumpListOfModules(modules); 614 } 615 616 void ListOfModules::init() { 617 clearOrInit(); 618 if (requiresProcmaps()) { 619 procmapsInit(&modules_); 620 } else { 621 DlIteratePhdrData data = {&modules_, true}; 622 dl_iterate_phdr(dl_iterate_phdr_cb, &data); 623 } 624 } 625 626 // When a custom loader is used, dl_iterate_phdr may not contain the full 627 // list of modules. Allow callers to fall back to using procmaps. 628 void ListOfModules::fallbackInit() { 629 if (!requiresProcmaps()) { 630 clearOrInit(); 631 procmapsInit(&modules_); 632 } else { 633 clear(); 634 } 635 } 636 637 // getrusage does not give us the current RSS, only the max RSS. 638 // Still, this is better than nothing if /proc/self/statm is not available 639 // for some reason, e.g. due to a sandbox. 640 static uptr GetRSSFromGetrusage() { 641 struct rusage usage; 642 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox. 643 return 0; 644 return usage.ru_maxrss << 10; // ru_maxrss is in Kb. 645 } 646 647 uptr GetRSS() { 648 if (!common_flags()->can_use_proc_maps_statm) 649 return GetRSSFromGetrusage(); 650 fd_t fd = OpenFile("/proc/self/statm", RdOnly); 651 if (fd == kInvalidFd) 652 return GetRSSFromGetrusage(); 653 char buf[64]; 654 uptr len = internal_read(fd, buf, sizeof(buf) - 1); 655 internal_close(fd); 656 if ((sptr)len <= 0) 657 return 0; 658 buf[len] = 0; 659 // The format of the file is: 660 // 1084 89 69 11 0 79 0 661 // We need the second number which is RSS in pages. 662 char *pos = buf; 663 // Skip the first number. 664 while (*pos >= '0' && *pos <= '9') 665 pos++; 666 // Skip whitespaces. 667 while (!(*pos >= '0' && *pos <= '9') && *pos != 0) 668 pos++; 669 // Read the number. 670 uptr rss = 0; 671 while (*pos >= '0' && *pos <= '9') 672 rss = rss * 10 + *pos++ - '0'; 673 return rss * GetPageSizeCached(); 674 } 675 676 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as 677 // they allocate memory. 678 u32 GetNumberOfCPUs() { 679 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD 680 u32 ncpu; 681 int req[2]; 682 uptr len = sizeof(ncpu); 683 req[0] = CTL_HW; 684 req[1] = HW_NCPU; 685 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0); 686 return ncpu; 687 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__) 688 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't 689 // exist in sched.h. That is the case for toolchains generated with older 690 // NDKs. 691 // This code doesn't work on AArch64 because internal_getdents makes use of 692 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64. 693 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY); 694 if (internal_iserror(fd)) 695 return 0; 696 InternalMmapVector<u8> buffer(4096); 697 uptr bytes_read = buffer.size(); 698 uptr n_cpus = 0; 699 u8 *d_type; 700 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read]; 701 while (true) { 702 if ((u8 *)entry >= &buffer[bytes_read]) { 703 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(), 704 buffer.size()); 705 if (internal_iserror(bytes_read) || !bytes_read) 706 break; 707 entry = (struct linux_dirent *)buffer.data(); 708 } 709 d_type = (u8 *)entry + entry->d_reclen - 1; 710 if (d_type >= &buffer[bytes_read] || 711 (u8 *)&entry->d_name[3] >= &buffer[bytes_read]) 712 break; 713 if (entry->d_ino != 0 && *d_type == DT_DIR) { 714 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' && 715 entry->d_name[2] == 'u' && 716 entry->d_name[3] >= '0' && entry->d_name[3] <= '9') 717 n_cpus++; 718 } 719 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen); 720 } 721 internal_close(fd); 722 return n_cpus; 723 #elif SANITIZER_SOLARIS 724 return sysconf(_SC_NPROCESSORS_ONLN); 725 #else 726 #if defined(CPU_COUNT) 727 cpu_set_t CPUs; 728 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0); 729 return CPU_COUNT(&CPUs); 730 #else 731 return 1; 732 #endif 733 #endif 734 } 735 736 #if SANITIZER_LINUX 737 738 # if SANITIZER_ANDROID 739 static atomic_uint8_t android_log_initialized; 740 741 void AndroidLogInit() { 742 openlog(GetProcessName(), 0, LOG_USER); 743 atomic_store(&android_log_initialized, 1, memory_order_release); 744 } 745 746 static bool ShouldLogAfterPrintf() { 747 return atomic_load(&android_log_initialized, memory_order_acquire); 748 } 749 750 extern "C" SANITIZER_WEAK_ATTRIBUTE 751 int async_safe_write_log(int pri, const char* tag, const char* msg); 752 extern "C" SANITIZER_WEAK_ATTRIBUTE 753 int __android_log_write(int prio, const char* tag, const char* msg); 754 755 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime. 756 #define SANITIZER_ANDROID_LOG_INFO 4 757 758 // async_safe_write_log is a new public version of __libc_write_log that is 759 // used behind syslog. It is preferable to syslog as it will not do any dynamic 760 // memory allocation or formatting. 761 // If the function is not available, syslog is preferred for L+ (it was broken 762 // pre-L) as __android_log_write triggers a racey behavior with the strncpy 763 // interceptor. Fallback to __android_log_write pre-L. 764 void WriteOneLineToSyslog(const char *s) { 765 if (&async_safe_write_log) { 766 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s); 767 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) { 768 syslog(LOG_INFO, "%s", s); 769 } else { 770 CHECK(&__android_log_write); 771 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s); 772 } 773 } 774 775 extern "C" SANITIZER_WEAK_ATTRIBUTE 776 void android_set_abort_message(const char *); 777 778 void SetAbortMessage(const char *str) { 779 if (&android_set_abort_message) 780 android_set_abort_message(str); 781 } 782 # else 783 void AndroidLogInit() {} 784 785 static bool ShouldLogAfterPrintf() { return true; } 786 787 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); } 788 789 void SetAbortMessage(const char *str) {} 790 # endif // SANITIZER_ANDROID 791 792 void LogMessageOnPrintf(const char *str) { 793 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf()) 794 WriteToSyslog(str); 795 } 796 797 #endif // SANITIZER_LINUX 798 799 #if SANITIZER_LINUX && !SANITIZER_GO 800 // glibc crashes when using clock_gettime from a preinit_array function as the 801 // vDSO function pointers haven't been initialized yet. __progname is 802 // initialized after the vDSO function pointers, so if it exists, is not null 803 // and is not empty, we can use clock_gettime. 804 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname; 805 INLINE bool CanUseVDSO() { 806 // Bionic is safe, it checks for the vDSO function pointers to be initialized. 807 if (SANITIZER_ANDROID) 808 return true; 809 if (&__progname && __progname && *__progname) 810 return true; 811 return false; 812 } 813 814 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling 815 // clock_gettime. real_clock_gettime only exists if clock_gettime is 816 // intercepted, so define it weakly and use it if available. 817 extern "C" SANITIZER_WEAK_ATTRIBUTE 818 int real_clock_gettime(u32 clk_id, void *tp); 819 u64 MonotonicNanoTime() { 820 timespec ts; 821 if (CanUseVDSO()) { 822 if (&real_clock_gettime) 823 real_clock_gettime(CLOCK_MONOTONIC, &ts); 824 else 825 clock_gettime(CLOCK_MONOTONIC, &ts); 826 } else { 827 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 828 } 829 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 830 } 831 #else 832 // Non-Linux & Go always use the syscall. 833 u64 MonotonicNanoTime() { 834 timespec ts; 835 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 836 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 837 } 838 #endif // SANITIZER_LINUX && !SANITIZER_GO 839 840 } // namespace __sanitizer 841 842 #endif 843