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 || SANITIZER_NETBSD || \ 18 SANITIZER_OPENBSD || SANITIZER_SOLARIS 19 20 #include "sanitizer_allocator_internal.h" 21 #include "sanitizer_atomic.h" 22 #include "sanitizer_common.h" 23 #include "sanitizer_file.h" 24 #include "sanitizer_flags.h" 25 #include "sanitizer_freebsd.h" 26 #include "sanitizer_getauxval.h" 27 #include "sanitizer_linux.h" 28 #include "sanitizer_placement_new.h" 29 #include "sanitizer_procmaps.h" 30 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 // Fast LWP private pointer getters in ThreadSelfTlsTcb(). 55 #include <machine/lwp_private.h> 56 #endif 57 58 #if SANITIZER_SOLARIS 59 #include <thread.h> 60 #endif 61 62 #if SANITIZER_ANDROID 63 #include <android/api-level.h> 64 #if !defined(CPU_COUNT) && !defined(__aarch64__) 65 #include <dirent.h> 66 #include <fcntl.h> 67 struct __sanitizer::linux_dirent { 68 long d_ino; 69 off_t d_off; 70 unsigned short d_reclen; 71 char d_name[]; 72 }; 73 #endif 74 #endif 75 76 #if !SANITIZER_ANDROID 77 #include <elf.h> 78 #include <unistd.h> 79 #endif 80 81 namespace __sanitizer { 82 83 SANITIZER_WEAK_ATTRIBUTE int 84 real_sigaction(int signum, const void *act, void *oldact); 85 86 int internal_sigaction(int signum, const void *act, void *oldact) { 87 #if !SANITIZER_GO 88 if (&real_sigaction) 89 return real_sigaction(signum, act, oldact); 90 #endif 91 return sigaction(signum, (const struct sigaction *)act, 92 (struct sigaction *)oldact); 93 } 94 95 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top, 96 uptr *stack_bottom) { 97 CHECK(stack_top); 98 CHECK(stack_bottom); 99 if (at_initialization) { 100 // This is the main thread. Libpthread may not be initialized yet. 101 struct rlimit rl; 102 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0); 103 104 // Find the mapping that contains a stack variable. 105 MemoryMappingLayout proc_maps(/*cache_enabled*/true); 106 if (proc_maps.Error()) { 107 *stack_top = *stack_bottom = 0; 108 return; 109 } 110 MemoryMappedSegment segment; 111 uptr prev_end = 0; 112 while (proc_maps.Next(&segment)) { 113 if ((uptr)&rl < segment.end) break; 114 prev_end = segment.end; 115 } 116 CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end); 117 118 // Get stacksize from rlimit, but clip it so that it does not overlap 119 // with other mappings. 120 uptr stacksize = rl.rlim_cur; 121 if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end; 122 // When running with unlimited stack size, we still want to set some limit. 123 // The unlimited stack size is caused by 'ulimit -s unlimited'. 124 // Also, for some reason, GNU make spawns subprocesses with unlimited stack. 125 if (stacksize > kMaxThreadStackSize) 126 stacksize = kMaxThreadStackSize; 127 *stack_top = segment.end; 128 *stack_bottom = segment.end - stacksize; 129 return; 130 } 131 uptr stacksize = 0; 132 void *stackaddr = nullptr; 133 #if SANITIZER_SOLARIS 134 stack_t ss; 135 CHECK_EQ(thr_stksegment(&ss), 0); 136 stacksize = ss.ss_size; 137 stackaddr = (char *)ss.ss_sp - stacksize; 138 #elif SANITIZER_OPENBSD 139 stack_t sattr; 140 CHECK_EQ(pthread_stackseg_np(pthread_self(), &sattr), 0); 141 stackaddr = sattr.ss_sp; 142 stacksize = sattr.ss_size; 143 #else // !SANITIZER_SOLARIS 144 pthread_attr_t attr; 145 pthread_attr_init(&attr); 146 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0); 147 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize); 148 pthread_attr_destroy(&attr); 149 #endif // SANITIZER_SOLARIS 150 151 *stack_top = (uptr)stackaddr + stacksize; 152 *stack_bottom = (uptr)stackaddr; 153 } 154 155 #if !SANITIZER_GO 156 bool SetEnv(const char *name, const char *value) { 157 void *f = dlsym(RTLD_NEXT, "setenv"); 158 if (!f) 159 return false; 160 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite); 161 setenv_ft setenv_f; 162 CHECK_EQ(sizeof(setenv_f), sizeof(f)); 163 internal_memcpy(&setenv_f, &f, sizeof(f)); 164 return setenv_f(name, value, 1) == 0; 165 } 166 #endif 167 168 __attribute__((unused)) static bool GetLibcVersion(int *major, int *minor, 169 int *patch) { 170 #ifdef _CS_GNU_LIBC_VERSION 171 char buf[64]; 172 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf)); 173 if (len >= sizeof(buf)) 174 return false; 175 buf[len] = 0; 176 static const char kGLibC[] = "glibc "; 177 if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0) 178 return false; 179 const char *p = buf + sizeof(kGLibC) - 1; 180 *major = internal_simple_strtoll(p, &p, 10); 181 *minor = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 182 *patch = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 183 return true; 184 #else 185 return false; 186 #endif 187 } 188 189 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO && \ 190 !SANITIZER_NETBSD && !SANITIZER_OPENBSD && !SANITIZER_SOLARIS 191 static uptr g_tls_size; 192 193 #ifdef __i386__ 194 # ifndef __GLIBC_PREREQ 195 # define CHECK_GET_TLS_STATIC_INFO_VERSION 1 196 # else 197 # define CHECK_GET_TLS_STATIC_INFO_VERSION (!__GLIBC_PREREQ(2, 27)) 198 # endif 199 #else 200 # define CHECK_GET_TLS_STATIC_INFO_VERSION 0 201 #endif 202 203 #if CHECK_GET_TLS_STATIC_INFO_VERSION 204 # define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall)) 205 #else 206 # define DL_INTERNAL_FUNCTION 207 #endif 208 209 namespace { 210 struct GetTlsStaticInfoCall { 211 typedef void (*get_tls_func)(size_t*, size_t*); 212 }; 213 struct GetTlsStaticInfoRegparmCall { 214 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION; 215 }; 216 217 template <typename T> 218 void CallGetTls(void* ptr, size_t* size, size_t* align) { 219 typename T::get_tls_func get_tls; 220 CHECK_EQ(sizeof(get_tls), sizeof(ptr)); 221 internal_memcpy(&get_tls, &ptr, sizeof(ptr)); 222 CHECK_NE(get_tls, 0); 223 get_tls(size, align); 224 } 225 226 bool CmpLibcVersion(int major, int minor, int patch) { 227 int ma; 228 int mi; 229 int pa; 230 if (!GetLibcVersion(&ma, &mi, &pa)) 231 return false; 232 if (ma > major) 233 return true; 234 if (ma < major) 235 return false; 236 if (mi > minor) 237 return true; 238 if (mi < minor) 239 return false; 240 return pa >= patch; 241 } 242 243 } // namespace 244 245 void InitTlsSize() { 246 // all current supported platforms have 16 bytes stack alignment 247 const size_t kStackAlign = 16; 248 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); 249 size_t tls_size = 0; 250 size_t tls_align = 0; 251 // On i?86, _dl_get_tls_static_info used to be internal_function, i.e. 252 // __attribute__((regparm(3), stdcall)) before glibc 2.27 and is normal 253 // function in 2.27 and later. 254 if (CHECK_GET_TLS_STATIC_INFO_VERSION && !CmpLibcVersion(2, 27, 0)) 255 CallGetTls<GetTlsStaticInfoRegparmCall>(get_tls_static_info_ptr, 256 &tls_size, &tls_align); 257 else 258 CallGetTls<GetTlsStaticInfoCall>(get_tls_static_info_ptr, 259 &tls_size, &tls_align); 260 if (tls_align < kStackAlign) 261 tls_align = kStackAlign; 262 g_tls_size = RoundUpTo(tls_size, tls_align); 263 } 264 #else 265 void InitTlsSize() { } 266 #endif // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO && 267 // !SANITIZER_NETBSD && !SANITIZER_SOLARIS 268 269 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) || \ 270 defined(__aarch64__) || defined(__powerpc64__) || defined(__s390__) || \ 271 defined(__arm__)) && \ 272 SANITIZER_LINUX && !SANITIZER_ANDROID 273 // sizeof(struct pthread) from glibc. 274 static atomic_uintptr_t thread_descriptor_size; 275 276 uptr ThreadDescriptorSize() { 277 uptr val = atomic_load_relaxed(&thread_descriptor_size); 278 if (val) 279 return val; 280 #if defined(__x86_64__) || defined(__i386__) || defined(__arm__) 281 int major; 282 int minor; 283 int patch; 284 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 285 /* sizeof(struct pthread) values from various glibc versions. */ 286 if (SANITIZER_X32) 287 val = 1728; // Assume only one particular version for x32. 288 // For ARM sizeof(struct pthread) changed in Glibc 2.23. 289 else if (SANITIZER_ARM) 290 val = minor <= 22 ? 1120 : 1216; 291 else if (minor <= 3) 292 val = FIRST_32_SECOND_64(1104, 1696); 293 else if (minor == 4) 294 val = FIRST_32_SECOND_64(1120, 1728); 295 else if (minor == 5) 296 val = FIRST_32_SECOND_64(1136, 1728); 297 else if (minor <= 9) 298 val = FIRST_32_SECOND_64(1136, 1712); 299 else if (minor == 10) 300 val = FIRST_32_SECOND_64(1168, 1776); 301 else if (minor == 11 || (minor == 12 && patch == 1)) 302 val = FIRST_32_SECOND_64(1168, 2288); 303 else if (minor <= 14) 304 val = FIRST_32_SECOND_64(1168, 2304); 305 else 306 val = FIRST_32_SECOND_64(1216, 2304); 307 } 308 #elif defined(__mips__) 309 // TODO(sagarthakur): add more values as per different glibc versions. 310 val = FIRST_32_SECOND_64(1152, 1776); 311 #elif defined(__aarch64__) 312 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22. 313 val = 1776; 314 #elif defined(__powerpc64__) 315 val = 1776; // from glibc.ppc64le 2.20-8.fc21 316 #elif defined(__s390__) 317 val = FIRST_32_SECOND_64(1152, 1776); // valid for glibc 2.22 318 #endif 319 if (val) 320 atomic_store_relaxed(&thread_descriptor_size, val); 321 return val; 322 } 323 324 // The offset at which pointer to self is located in the thread descriptor. 325 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16); 326 327 uptr ThreadSelfOffset() { 328 return kThreadSelfOffset; 329 } 330 331 #if defined(__mips__) || defined(__powerpc64__) 332 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb 333 // head structure. It lies before the static tls blocks. 334 static uptr TlsPreTcbSize() { 335 # if defined(__mips__) 336 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 337 # elif defined(__powerpc64__) 338 const uptr kTcbHead = 88; // sizeof (tcbhead_t) 339 # endif 340 const uptr kTlsAlign = 16; 341 const uptr kTlsPreTcbSize = 342 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign); 343 return kTlsPreTcbSize; 344 } 345 #endif 346 347 uptr ThreadSelf() { 348 uptr descr_addr; 349 # if defined(__i386__) 350 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 351 # elif defined(__x86_64__) 352 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 353 # elif defined(__mips__) 354 // MIPS uses TLS variant I. The thread pointer (in hardware register $29) 355 // points to the end of the TCB + 0x7000. The pthread_descr structure is 356 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 357 // TCB and the size of pthread_descr. 358 const uptr kTlsTcbOffset = 0x7000; 359 uptr thread_pointer; 360 asm volatile(".set push;\ 361 .set mips64r2;\ 362 rdhwr %0,$29;\ 363 .set pop" : "=r" (thread_pointer)); 364 descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize(); 365 # elif defined(__aarch64__) || defined(__arm__) 366 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) - 367 ThreadDescriptorSize(); 368 # elif defined(__s390__) 369 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()); 370 # elif defined(__powerpc64__) 371 // PPC64LE uses TLS variant I. The thread pointer (in GPR 13) 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("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset)); 378 descr_addr = thread_pointer - TlsPreTcbSize(); 379 # else 380 # error "unsupported CPU arch" 381 # endif 382 return descr_addr; 383 } 384 #endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX 385 386 #if SANITIZER_FREEBSD 387 static void **ThreadSelfSegbase() { 388 void **segbase = 0; 389 # if defined(__i386__) 390 // sysarch(I386_GET_GSBASE, segbase); 391 __asm __volatile("mov %%gs:0, %0" : "=r" (segbase)); 392 # elif defined(__x86_64__) 393 // sysarch(AMD64_GET_FSBASE, segbase); 394 __asm __volatile("movq %%fs:0, %0" : "=r" (segbase)); 395 # else 396 # error "unsupported CPU arch" 397 # endif 398 return segbase; 399 } 400 401 uptr ThreadSelf() { 402 return (uptr)ThreadSelfSegbase()[2]; 403 } 404 #endif // SANITIZER_FREEBSD 405 406 #if SANITIZER_NETBSD 407 static struct tls_tcb * ThreadSelfTlsTcb() { 408 struct tls_tcb * tcb; 409 # ifdef __HAVE___LWP_GETTCB_FAST 410 tcb = (struct tls_tcb *)__lwp_gettcb_fast(); 411 # elif defined(__HAVE___LWP_GETPRIVATE_FAST) 412 tcb = (struct tls_tcb *)__lwp_getprivate_fast(); 413 # endif 414 return tcb; 415 } 416 417 uptr ThreadSelf() { 418 return (uptr)ThreadSelfTlsTcb()->tcb_pthread; 419 } 420 421 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) { 422 const Elf_Phdr *hdr = info->dlpi_phdr; 423 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum; 424 425 for (; hdr != last_hdr; ++hdr) { 426 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) { 427 *(uptr*)data = hdr->p_memsz; 428 break; 429 } 430 } 431 return 0; 432 } 433 #endif // SANITIZER_NETBSD 434 435 #if !SANITIZER_GO 436 static void GetTls(uptr *addr, uptr *size) { 437 #if SANITIZER_LINUX && !SANITIZER_ANDROID 438 # if defined(__x86_64__) || defined(__i386__) || defined(__s390__) 439 *addr = ThreadSelf(); 440 *size = GetTlsSize(); 441 *addr -= *size; 442 *addr += ThreadDescriptorSize(); 443 # elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__) \ 444 || defined(__arm__) 445 *addr = ThreadSelf(); 446 *size = GetTlsSize(); 447 # else 448 *addr = 0; 449 *size = 0; 450 # endif 451 #elif SANITIZER_FREEBSD 452 void** segbase = ThreadSelfSegbase(); 453 *addr = 0; 454 *size = 0; 455 if (segbase != 0) { 456 // tcbalign = 16 457 // tls_size = round(tls_static_space, tcbalign); 458 // dtv = segbase[1]; 459 // dtv[2] = segbase - tls_static_space; 460 void **dtv = (void**) segbase[1]; 461 *addr = (uptr) dtv[2]; 462 *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]); 463 } 464 #elif SANITIZER_NETBSD 465 struct tls_tcb * const tcb = ThreadSelfTlsTcb(); 466 *addr = 0; 467 *size = 0; 468 if (tcb != 0) { 469 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program). 470 // ld.elf_so hardcodes the index 1. 471 dl_iterate_phdr(GetSizeFromHdr, size); 472 473 if (*size != 0) { 474 // The block has been found and tcb_dtv[1] contains the base address 475 *addr = (uptr)tcb->tcb_dtv[1]; 476 } 477 } 478 #elif SANITIZER_OPENBSD 479 *addr = 0; 480 *size = 0; 481 #elif SANITIZER_ANDROID 482 *addr = 0; 483 *size = 0; 484 #elif SANITIZER_SOLARIS 485 // FIXME 486 *addr = 0; 487 *size = 0; 488 #else 489 # error "Unknown OS" 490 #endif 491 } 492 #endif 493 494 #if !SANITIZER_GO 495 uptr GetTlsSize() { 496 #if SANITIZER_FREEBSD || SANITIZER_ANDROID || SANITIZER_NETBSD || \ 497 SANITIZER_OPENBSD || SANITIZER_SOLARIS 498 uptr addr, size; 499 GetTls(&addr, &size); 500 return size; 501 #elif defined(__mips__) || defined(__powerpc64__) 502 return RoundUpTo(g_tls_size + TlsPreTcbSize(), 16); 503 #else 504 return g_tls_size; 505 #endif 506 } 507 #endif 508 509 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, 510 uptr *tls_addr, uptr *tls_size) { 511 #if SANITIZER_GO 512 // Stub implementation for Go. 513 *stk_addr = *stk_size = *tls_addr = *tls_size = 0; 514 #else 515 GetTls(tls_addr, tls_size); 516 517 uptr stack_top, stack_bottom; 518 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); 519 *stk_addr = stack_bottom; 520 *stk_size = stack_top - stack_bottom; 521 522 if (!main) { 523 // If stack and tls intersect, make them non-intersecting. 524 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { 525 CHECK_GT(*tls_addr + *tls_size, *stk_addr); 526 CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size); 527 *stk_size -= *tls_size; 528 *tls_addr = *stk_addr + *stk_size; 529 } 530 } 531 #endif 532 } 533 534 #if !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 535 typedef ElfW(Phdr) Elf_Phdr; 536 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2 537 #define Elf_Phdr XElf32_Phdr 538 #define dl_phdr_info xdl_phdr_info 539 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b)) 540 #endif // !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 541 542 struct DlIteratePhdrData { 543 InternalMmapVectorNoCtor<LoadedModule> *modules; 544 bool first; 545 }; 546 547 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) { 548 DlIteratePhdrData *data = (DlIteratePhdrData*)arg; 549 InternalScopedString module_name(kMaxPathLength); 550 if (data->first) { 551 data->first = false; 552 // First module is the binary itself. 553 ReadBinaryNameCached(module_name.data(), module_name.size()); 554 } else if (info->dlpi_name) { 555 module_name.append("%s", info->dlpi_name); 556 } 557 if (module_name[0] == '\0') 558 return 0; 559 LoadedModule cur_module; 560 cur_module.set(module_name.data(), info->dlpi_addr); 561 for (int i = 0; i < (int)info->dlpi_phnum; i++) { 562 const Elf_Phdr *phdr = &info->dlpi_phdr[i]; 563 if (phdr->p_type == PT_LOAD) { 564 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr; 565 uptr cur_end = cur_beg + phdr->p_memsz; 566 bool executable = phdr->p_flags & PF_X; 567 bool writable = phdr->p_flags & PF_W; 568 cur_module.addAddressRange(cur_beg, cur_end, executable, 569 writable); 570 } 571 } 572 data->modules->push_back(cur_module); 573 return 0; 574 } 575 576 #if SANITIZER_ANDROID && __ANDROID_API__ < 21 577 extern "C" __attribute__((weak)) int dl_iterate_phdr( 578 int (*)(struct dl_phdr_info *, size_t, void *), void *); 579 #endif 580 581 static bool requiresProcmaps() { 582 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22 583 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken. 584 // The runtime check allows the same library to work with 585 // both K and L (and future) Android releases. 586 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1; 587 #else 588 return false; 589 #endif 590 } 591 592 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) { 593 MemoryMappingLayout memory_mapping(/*cache_enabled*/true); 594 memory_mapping.DumpListOfModules(modules); 595 } 596 597 void ListOfModules::init() { 598 clearOrInit(); 599 if (requiresProcmaps()) { 600 procmapsInit(&modules_); 601 } else { 602 DlIteratePhdrData data = {&modules_, true}; 603 dl_iterate_phdr(dl_iterate_phdr_cb, &data); 604 } 605 } 606 607 // When a custom loader is used, dl_iterate_phdr may not contain the full 608 // list of modules. Allow callers to fall back to using procmaps. 609 void ListOfModules::fallbackInit() { 610 if (!requiresProcmaps()) { 611 clearOrInit(); 612 procmapsInit(&modules_); 613 } else { 614 clear(); 615 } 616 } 617 618 // getrusage does not give us the current RSS, only the max RSS. 619 // Still, this is better than nothing if /proc/self/statm is not available 620 // for some reason, e.g. due to a sandbox. 621 static uptr GetRSSFromGetrusage() { 622 struct rusage usage; 623 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox. 624 return 0; 625 return usage.ru_maxrss << 10; // ru_maxrss is in Kb. 626 } 627 628 uptr GetRSS() { 629 if (!common_flags()->can_use_proc_maps_statm) 630 return GetRSSFromGetrusage(); 631 fd_t fd = OpenFile("/proc/self/statm", RdOnly); 632 if (fd == kInvalidFd) 633 return GetRSSFromGetrusage(); 634 char buf[64]; 635 uptr len = internal_read(fd, buf, sizeof(buf) - 1); 636 internal_close(fd); 637 if ((sptr)len <= 0) 638 return 0; 639 buf[len] = 0; 640 // The format of the file is: 641 // 1084 89 69 11 0 79 0 642 // We need the second number which is RSS in pages. 643 char *pos = buf; 644 // Skip the first number. 645 while (*pos >= '0' && *pos <= '9') 646 pos++; 647 // Skip whitespaces. 648 while (!(*pos >= '0' && *pos <= '9') && *pos != 0) 649 pos++; 650 // Read the number. 651 uptr rss = 0; 652 while (*pos >= '0' && *pos <= '9') 653 rss = rss * 10 + *pos++ - '0'; 654 return rss * GetPageSizeCached(); 655 } 656 657 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as 658 // they allocate memory. 659 u32 GetNumberOfCPUs() { 660 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD 661 u32 ncpu; 662 int req[2]; 663 uptr len = sizeof(ncpu); 664 req[0] = CTL_HW; 665 req[1] = HW_NCPU; 666 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0); 667 return ncpu; 668 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__) 669 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't 670 // exist in sched.h. That is the case for toolchains generated with older 671 // NDKs. 672 // This code doesn't work on AArch64 because internal_getdents makes use of 673 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64. 674 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY); 675 if (internal_iserror(fd)) 676 return 0; 677 InternalMmapVector<u8> buffer(4096); 678 uptr bytes_read = buffer.size(); 679 uptr n_cpus = 0; 680 u8 *d_type; 681 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read]; 682 while (true) { 683 if ((u8 *)entry >= &buffer[bytes_read]) { 684 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(), 685 buffer.size()); 686 if (internal_iserror(bytes_read) || !bytes_read) 687 break; 688 entry = (struct linux_dirent *)buffer.data(); 689 } 690 d_type = (u8 *)entry + entry->d_reclen - 1; 691 if (d_type >= &buffer[bytes_read] || 692 (u8 *)&entry->d_name[3] >= &buffer[bytes_read]) 693 break; 694 if (entry->d_ino != 0 && *d_type == DT_DIR) { 695 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' && 696 entry->d_name[2] == 'u' && 697 entry->d_name[3] >= '0' && entry->d_name[3] <= '9') 698 n_cpus++; 699 } 700 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen); 701 } 702 internal_close(fd); 703 return n_cpus; 704 #elif SANITIZER_SOLARIS 705 return sysconf(_SC_NPROCESSORS_ONLN); 706 #else 707 cpu_set_t CPUs; 708 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0); 709 return CPU_COUNT(&CPUs); 710 #endif 711 } 712 713 #if SANITIZER_LINUX 714 715 # if SANITIZER_ANDROID 716 static atomic_uint8_t android_log_initialized; 717 718 void AndroidLogInit() { 719 openlog(GetProcessName(), 0, LOG_USER); 720 atomic_store(&android_log_initialized, 1, memory_order_release); 721 } 722 723 static bool ShouldLogAfterPrintf() { 724 return atomic_load(&android_log_initialized, memory_order_acquire); 725 } 726 727 extern "C" SANITIZER_WEAK_ATTRIBUTE 728 int async_safe_write_log(int pri, const char* tag, const char* msg); 729 extern "C" SANITIZER_WEAK_ATTRIBUTE 730 int __android_log_write(int prio, const char* tag, const char* msg); 731 732 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime. 733 #define SANITIZER_ANDROID_LOG_INFO 4 734 735 // async_safe_write_log is a new public version of __libc_write_log that is 736 // used behind syslog. It is preferable to syslog as it will not do any dynamic 737 // memory allocation or formatting. 738 // If the function is not available, syslog is preferred for L+ (it was broken 739 // pre-L) as __android_log_write triggers a racey behavior with the strncpy 740 // interceptor. Fallback to __android_log_write pre-L. 741 void WriteOneLineToSyslog(const char *s) { 742 if (&async_safe_write_log) { 743 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s); 744 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) { 745 syslog(LOG_INFO, "%s", s); 746 } else { 747 CHECK(&__android_log_write); 748 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s); 749 } 750 } 751 752 extern "C" SANITIZER_WEAK_ATTRIBUTE 753 void android_set_abort_message(const char *); 754 755 void SetAbortMessage(const char *str) { 756 if (&android_set_abort_message) 757 android_set_abort_message(str); 758 } 759 # else 760 void AndroidLogInit() {} 761 762 static bool ShouldLogAfterPrintf() { return true; } 763 764 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); } 765 766 void SetAbortMessage(const char *str) {} 767 # endif // SANITIZER_ANDROID 768 769 void LogMessageOnPrintf(const char *str) { 770 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf()) 771 WriteToSyslog(str); 772 } 773 774 #endif // SANITIZER_LINUX 775 776 #if SANITIZER_LINUX && !SANITIZER_GO 777 // glibc crashes when using clock_gettime from a preinit_array function as the 778 // vDSO function pointers haven't been initialized yet. __progname is 779 // initialized after the vDSO function pointers, so if it exists, is not null 780 // and is not empty, we can use clock_gettime. 781 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname; 782 INLINE bool CanUseVDSO() { 783 // Bionic is safe, it checks for the vDSO function pointers to be initialized. 784 if (SANITIZER_ANDROID) 785 return true; 786 if (&__progname && __progname && *__progname) 787 return true; 788 return false; 789 } 790 791 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling 792 // clock_gettime. real_clock_gettime only exists if clock_gettime is 793 // intercepted, so define it weakly and use it if available. 794 extern "C" SANITIZER_WEAK_ATTRIBUTE 795 int real_clock_gettime(u32 clk_id, void *tp); 796 u64 MonotonicNanoTime() { 797 timespec ts; 798 if (CanUseVDSO()) { 799 if (&real_clock_gettime) 800 real_clock_gettime(CLOCK_MONOTONIC, &ts); 801 else 802 clock_gettime(CLOCK_MONOTONIC, &ts); 803 } else { 804 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 805 } 806 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 807 } 808 #else 809 // Non-Linux & Go always use the syscall. 810 u64 MonotonicNanoTime() { 811 timespec ts; 812 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 813 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 814 } 815 #endif // SANITIZER_LINUX && !SANITIZER_GO 816 817 #if !SANITIZER_OPENBSD 818 void ReExec() { 819 const char *pathname = "/proc/self/exe"; 820 821 #if SANITIZER_NETBSD 822 static const int name[] = { 823 CTL_KERN, 824 KERN_PROC_ARGS, 825 -1, 826 KERN_PROC_PATHNAME, 827 }; 828 char path[400]; 829 uptr len; 830 831 len = sizeof(path); 832 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1) 833 pathname = path; 834 #elif SANITIZER_SOLARIS 835 pathname = getexecname(); 836 CHECK_NE(pathname, NULL); 837 #elif SANITIZER_USE_GETAUXVAL 838 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that 839 // rely on that will fail to load shared libraries. Query AT_EXECFN instead. 840 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN)); 841 #endif 842 843 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron()); 844 int rverrno; 845 CHECK_EQ(internal_iserror(rv, &rverrno), true); 846 Printf("execve failed, errno %d\n", rverrno); 847 Die(); 848 } 849 #endif // !SANITIZER_OPENBSD 850 851 } // namespace __sanitizer 852 853 #endif 854
Indexes created Sun Sep 21 15:09:59 GMT 2025