1 //===-- sanitizer_linux_libcdep.cpp ---------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is shared between AddressSanitizer and ThreadSanitizer 10 // run-time libraries and implements linux-specific functions from 11 // sanitizer_libc.h. 12 //===----------------------------------------------------------------------===// 13 14 #include "sanitizer_platform.h" 15 16 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \ 17 SANITIZER_OPENBSD || SANITIZER_SOLARIS 18 19 #include "sanitizer_allocator_internal.h" 20 #include "sanitizer_atomic.h" 21 #include "sanitizer_common.h" 22 #include "sanitizer_file.h" 23 #include "sanitizer_flags.h" 24 #include "sanitizer_freebsd.h" 25 #include "sanitizer_getauxval.h" 26 #include "sanitizer_glibc_version.h" 27 #include "sanitizer_linux.h" 28 #include "sanitizer_placement_new.h" 29 #include "sanitizer_procmaps.h" 30 31 #include <dlfcn.h> // for dlsym() 32 #include <link.h> 33 #include <pthread.h> 34 #include <signal.h> 35 #include <sys/resource.h> 36 #include <syslog.h> 37 38 #if SANITIZER_FREEBSD 39 #include <pthread_np.h> 40 #include <osreldate.h> 41 #include <sys/sysctl.h> 42 #define pthread_getattr_np pthread_attr_get_np 43 #endif 44 45 #if SANITIZER_OPENBSD 46 #include <pthread_np.h> 47 #include <sys/sysctl.h> 48 #endif 49 50 #if SANITIZER_NETBSD 51 #include <sys/sysctl.h> 52 #include <sys/tls.h> 53 #endif 54 55 #if SANITIZER_SOLARIS 56 #include <stdlib.h> 57 #include <thread.h> 58 #endif 59 60 #if SANITIZER_ANDROID 61 #include <android/api-level.h> 62 #if !defined(CPU_COUNT) && !defined(__aarch64__) 63 #include <dirent.h> 64 #include <fcntl.h> 65 struct __sanitizer::linux_dirent { 66 long d_ino; 67 off_t d_off; 68 unsigned short d_reclen; 69 char d_name[]; 70 }; 71 #endif 72 #endif 73 74 #if !SANITIZER_ANDROID 75 #include <elf.h> 76 #include <unistd.h> 77 #endif 78 79 namespace __sanitizer { 80 81 SANITIZER_WEAK_ATTRIBUTE int 82 real_sigaction(int signum, const void *act, void *oldact); 83 84 int internal_sigaction(int signum, const void *act, void *oldact) { 85 #if !SANITIZER_GO 86 if (&real_sigaction) 87 return real_sigaction(signum, act, oldact); 88 #endif 89 return sigaction(signum, (const struct sigaction *)act, 90 (struct sigaction *)oldact); 91 } 92 93 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top, 94 uptr *stack_bottom) { 95 CHECK(stack_top); 96 CHECK(stack_bottom); 97 if (at_initialization) { 98 // This is the main thread. Libpthread may not be initialized yet. 99 struct rlimit rl; 100 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0); 101 102 // Find the mapping that contains a stack variable. 103 MemoryMappingLayout proc_maps(/*cache_enabled*/true); 104 if (proc_maps.Error()) { 105 *stack_top = *stack_bottom = 0; 106 return; 107 } 108 MemoryMappedSegment segment; 109 uptr prev_end = 0; 110 while (proc_maps.Next(&segment)) { 111 if ((uptr)&rl < segment.end) break; 112 prev_end = segment.end; 113 } 114 CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end); 115 116 // Get stacksize from rlimit, but clip it so that it does not overlap 117 // with other mappings. 118 uptr stacksize = rl.rlim_cur; 119 if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end; 120 // When running with unlimited stack size, we still want to set some limit. 121 // The unlimited stack size is caused by 'ulimit -s unlimited'. 122 // Also, for some reason, GNU make spawns subprocesses with unlimited stack. 123 if (stacksize > kMaxThreadStackSize) 124 stacksize = kMaxThreadStackSize; 125 *stack_top = segment.end; 126 *stack_bottom = segment.end - stacksize; 127 return; 128 } 129 uptr stacksize = 0; 130 void *stackaddr = nullptr; 131 #if SANITIZER_SOLARIS 132 stack_t ss; 133 CHECK_EQ(thr_stksegment(&ss), 0); 134 stacksize = ss.ss_size; 135 stackaddr = (char *)ss.ss_sp - stacksize; 136 #elif SANITIZER_OPENBSD 137 stack_t sattr; 138 CHECK_EQ(pthread_stackseg_np(pthread_self(), &sattr), 0); 139 stackaddr = sattr.ss_sp; 140 stacksize = sattr.ss_size; 141 #else // !SANITIZER_SOLARIS 142 pthread_attr_t attr; 143 pthread_attr_init(&attr); 144 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0); 145 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize); 146 pthread_attr_destroy(&attr); 147 #endif // SANITIZER_SOLARIS 148 149 *stack_top = (uptr)stackaddr + stacksize; 150 *stack_bottom = (uptr)stackaddr; 151 } 152 153 #if !SANITIZER_GO 154 bool SetEnv(const char *name, const char *value) { 155 void *f = dlsym(RTLD_NEXT, "setenv"); 156 if (!f) 157 return false; 158 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite); 159 setenv_ft setenv_f; 160 CHECK_EQ(sizeof(setenv_f), sizeof(f)); 161 internal_memcpy(&setenv_f, &f, sizeof(f)); 162 return setenv_f(name, value, 1) == 0; 163 } 164 #endif 165 166 __attribute__((unused)) static bool GetLibcVersion(int *major, int *minor, 167 int *patch) { 168 #ifdef _CS_GNU_LIBC_VERSION 169 char buf[64]; 170 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf)); 171 if (len >= sizeof(buf)) 172 return false; 173 buf[len] = 0; 174 static const char kGLibC[] = "glibc "; 175 if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0) 176 return false; 177 const char *p = buf + sizeof(kGLibC) - 1; 178 *major = internal_simple_strtoll(p, &p, 10); 179 *minor = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 180 *patch = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 181 return true; 182 #else 183 return false; 184 #endif 185 } 186 187 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO && \ 188 !SANITIZER_NETBSD && !SANITIZER_OPENBSD && !SANITIZER_SOLARIS 189 static uptr g_tls_size; 190 191 #ifdef __i386__ 192 # define CHECK_GET_TLS_STATIC_INFO_VERSION (!__GLIBC_PREREQ(2, 27)) 193 #else 194 # define CHECK_GET_TLS_STATIC_INFO_VERSION 0 195 #endif 196 197 #if CHECK_GET_TLS_STATIC_INFO_VERSION 198 # define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall)) 199 #else 200 # define DL_INTERNAL_FUNCTION 201 #endif 202 203 namespace { 204 struct GetTlsStaticInfoCall { 205 typedef void (*get_tls_func)(size_t*, size_t*); 206 }; 207 struct GetTlsStaticInfoRegparmCall { 208 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION; 209 }; 210 211 template <typename T> 212 void CallGetTls(void* ptr, size_t* size, size_t* align) { 213 typename T::get_tls_func get_tls; 214 CHECK_EQ(sizeof(get_tls), sizeof(ptr)); 215 internal_memcpy(&get_tls, &ptr, sizeof(ptr)); 216 CHECK_NE(get_tls, 0); 217 get_tls(size, align); 218 } 219 220 bool CmpLibcVersion(int major, int minor, int patch) { 221 int ma; 222 int mi; 223 int pa; 224 if (!GetLibcVersion(&ma, &mi, &pa)) 225 return false; 226 if (ma > major) 227 return true; 228 if (ma < major) 229 return false; 230 if (mi > minor) 231 return true; 232 if (mi < minor) 233 return false; 234 return pa >= patch; 235 } 236 237 } // namespace 238 239 void InitTlsSize() { 240 // all current supported platforms have 16 bytes stack alignment 241 const size_t kStackAlign = 16; 242 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); 243 size_t tls_size = 0; 244 size_t tls_align = 0; 245 // On i?86, _dl_get_tls_static_info used to be internal_function, i.e. 246 // __attribute__((regparm(3), stdcall)) before glibc 2.27 and is normal 247 // function in 2.27 and later. 248 if (CHECK_GET_TLS_STATIC_INFO_VERSION && !CmpLibcVersion(2, 27, 0)) 249 CallGetTls<GetTlsStaticInfoRegparmCall>(get_tls_static_info_ptr, 250 &tls_size, &tls_align); 251 else 252 CallGetTls<GetTlsStaticInfoCall>(get_tls_static_info_ptr, 253 &tls_size, &tls_align); 254 if (tls_align < kStackAlign) 255 tls_align = kStackAlign; 256 g_tls_size = RoundUpTo(tls_size, tls_align); 257 } 258 #else 259 void InitTlsSize() { } 260 #endif // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO && 261 // !SANITIZER_NETBSD && !SANITIZER_SOLARIS 262 263 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) || \ 264 defined(__aarch64__) || defined(__powerpc64__) || defined(__s390__) || \ 265 defined(__arm__)) && \ 266 SANITIZER_LINUX && !SANITIZER_ANDROID 267 // sizeof(struct pthread) from glibc. 268 static atomic_uintptr_t thread_descriptor_size; 269 270 uptr ThreadDescriptorSize() { 271 uptr val = atomic_load_relaxed(&thread_descriptor_size); 272 if (val) 273 return val; 274 #if defined(__x86_64__) || defined(__i386__) || defined(__arm__) 275 int major; 276 int minor; 277 int patch; 278 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 279 /* sizeof(struct pthread) values from various glibc versions. */ 280 if (SANITIZER_X32) 281 val = 1728; // Assume only one particular version for x32. 282 // For ARM sizeof(struct pthread) changed in Glibc 2.23. 283 else if (SANITIZER_ARM) 284 val = minor <= 22 ? 1120 : 1216; 285 else if (minor <= 3) 286 val = FIRST_32_SECOND_64(1104, 1696); 287 else if (minor == 4) 288 val = FIRST_32_SECOND_64(1120, 1728); 289 else if (minor == 5) 290 val = FIRST_32_SECOND_64(1136, 1728); 291 else if (minor <= 9) 292 val = FIRST_32_SECOND_64(1136, 1712); 293 else if (minor == 10) 294 val = FIRST_32_SECOND_64(1168, 1776); 295 else if (minor == 11 || (minor == 12 && patch == 1)) 296 val = FIRST_32_SECOND_64(1168, 2288); 297 else if (minor <= 14) 298 val = FIRST_32_SECOND_64(1168, 2304); 299 else 300 val = FIRST_32_SECOND_64(1216, 2304); 301 } 302 #elif defined(__mips__) 303 // TODO(sagarthakur): add more values as per different glibc versions. 304 val = FIRST_32_SECOND_64(1152, 1776); 305 #elif defined(__aarch64__) 306 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22. 307 val = 1776; 308 #elif defined(__powerpc64__) 309 val = 1776; // from glibc.ppc64le 2.20-8.fc21 310 #elif defined(__s390__) 311 val = FIRST_32_SECOND_64(1152, 1776); // valid for glibc 2.22 312 #endif 313 if (val) 314 atomic_store_relaxed(&thread_descriptor_size, val); 315 return val; 316 } 317 318 // The offset at which pointer to self is located in the thread descriptor. 319 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16); 320 321 uptr ThreadSelfOffset() { 322 return kThreadSelfOffset; 323 } 324 325 #if defined(__mips__) || defined(__powerpc64__) 326 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb 327 // head structure. It lies before the static tls blocks. 328 static uptr TlsPreTcbSize() { 329 # if defined(__mips__) 330 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 331 # elif defined(__powerpc64__) 332 const uptr kTcbHead = 88; // sizeof (tcbhead_t) 333 # endif 334 const uptr kTlsAlign = 16; 335 const uptr kTlsPreTcbSize = 336 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign); 337 return kTlsPreTcbSize; 338 } 339 #endif 340 341 uptr ThreadSelf() { 342 uptr descr_addr; 343 # if defined(__i386__) 344 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 345 # elif defined(__x86_64__) 346 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 347 # elif defined(__mips__) 348 // MIPS uses TLS variant I. The thread pointer (in hardware register $29) 349 // points to the end of the TCB + 0x7000. The pthread_descr structure is 350 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 351 // TCB and the size of pthread_descr. 352 const uptr kTlsTcbOffset = 0x7000; 353 uptr thread_pointer; 354 asm volatile(".set push;\ 355 .set mips64r2;\ 356 rdhwr %0,$29;\ 357 .set pop" : "=r" (thread_pointer)); 358 descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize(); 359 # elif defined(__aarch64__) || defined(__arm__) 360 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) - 361 ThreadDescriptorSize(); 362 # elif defined(__s390__) 363 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()); 364 # elif defined(__powerpc64__) 365 // PPC64LE uses TLS variant I. The thread pointer (in GPR 13) 366 // points to the end of the TCB + 0x7000. The pthread_descr structure is 367 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 368 // TCB and the size of pthread_descr. 369 const uptr kTlsTcbOffset = 0x7000; 370 uptr thread_pointer; 371 asm("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset)); 372 descr_addr = thread_pointer - TlsPreTcbSize(); 373 # else 374 # error "unsupported CPU arch" 375 # endif 376 return descr_addr; 377 } 378 #endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX 379 380 #if SANITIZER_FREEBSD 381 static void **ThreadSelfSegbase() { 382 void **segbase = 0; 383 # if defined(__i386__) 384 // sysarch(I386_GET_GSBASE, segbase); 385 __asm __volatile("mov %%gs:0, %0" : "=r" (segbase)); 386 # elif defined(__x86_64__) 387 // sysarch(AMD64_GET_FSBASE, segbase); 388 __asm __volatile("movq %%fs:0, %0" : "=r" (segbase)); 389 # else 390 # error "unsupported CPU arch" 391 # endif 392 return segbase; 393 } 394 395 uptr ThreadSelf() { 396 return (uptr)ThreadSelfSegbase()[2]; 397 } 398 #endif // SANITIZER_FREEBSD 399 400 #if SANITIZER_NETBSD 401 static struct tls_tcb * ThreadSelfTlsTcb() { 402 struct tls_tcb * tcb; 403 # ifdef __HAVE___LWP_GETTCB_FAST 404 tcb = (struct tls_tcb *)__lwp_gettcb_fast(); 405 # elif defined(__HAVE___LWP_GETPRIVATE_FAST) 406 tcb = (struct tls_tcb *)__lwp_getprivate_fast(); 407 # endif 408 return tcb; 409 } 410 411 uptr ThreadSelf() { 412 return (uptr)ThreadSelfTlsTcb()->tcb_pthread; 413 } 414 415 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) { 416 const Elf_Phdr *hdr = info->dlpi_phdr; 417 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum; 418 419 for (; hdr != last_hdr; ++hdr) { 420 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) { 421 *(uptr*)data = hdr->p_memsz; 422 break; 423 } 424 } 425 return 0; 426 } 427 #endif // SANITIZER_NETBSD 428 429 #if !SANITIZER_GO 430 static void GetTls(uptr *addr, uptr *size) { 431 #if SANITIZER_LINUX && !SANITIZER_ANDROID 432 # if defined(__x86_64__) || defined(__i386__) || defined(__s390__) 433 *addr = ThreadSelf(); 434 *size = GetTlsSize(); 435 *addr -= *size; 436 *addr += ThreadDescriptorSize(); 437 # elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__) \ 438 || defined(__arm__) 439 *addr = ThreadSelf(); 440 *size = GetTlsSize(); 441 # else 442 *addr = 0; 443 *size = 0; 444 # endif 445 #elif SANITIZER_FREEBSD 446 void** segbase = ThreadSelfSegbase(); 447 *addr = 0; 448 *size = 0; 449 if (segbase != 0) { 450 // tcbalign = 16 451 // tls_size = round(tls_static_space, tcbalign); 452 // dtv = segbase[1]; 453 // dtv[2] = segbase - tls_static_space; 454 void **dtv = (void**) segbase[1]; 455 *addr = (uptr) dtv[2]; 456 *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]); 457 } 458 #elif SANITIZER_NETBSD 459 struct tls_tcb * const tcb = ThreadSelfTlsTcb(); 460 *addr = 0; 461 *size = 0; 462 if (tcb != 0) { 463 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program). 464 // ld.elf_so hardcodes the index 1. 465 dl_iterate_phdr(GetSizeFromHdr, size); 466 467 if (*size != 0) { 468 // The block has been found and tcb_dtv[1] contains the base address 469 *addr = (uptr)tcb->tcb_dtv[1]; 470 } 471 } 472 #elif SANITIZER_OPENBSD 473 *addr = 0; 474 *size = 0; 475 #elif SANITIZER_ANDROID 476 *addr = 0; 477 *size = 0; 478 #elif SANITIZER_SOLARIS 479 // FIXME 480 *addr = 0; 481 *size = 0; 482 #else 483 # error "Unknown OS" 484 #endif 485 } 486 #endif 487 488 #if !SANITIZER_GO 489 uptr GetTlsSize() { 490 #if SANITIZER_FREEBSD || SANITIZER_ANDROID || SANITIZER_NETBSD || \ 491 SANITIZER_OPENBSD || SANITIZER_SOLARIS 492 uptr addr, size; 493 GetTls(&addr, &size); 494 return size; 495 #elif defined(__mips__) || defined(__powerpc64__) 496 return RoundUpTo(g_tls_size + TlsPreTcbSize(), 16); 497 #else 498 return g_tls_size; 499 #endif 500 } 501 #endif 502 503 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, 504 uptr *tls_addr, uptr *tls_size) { 505 #if SANITIZER_GO 506 // Stub implementation for Go. 507 *stk_addr = *stk_size = *tls_addr = *tls_size = 0; 508 #else 509 GetTls(tls_addr, tls_size); 510 511 uptr stack_top, stack_bottom; 512 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); 513 *stk_addr = stack_bottom; 514 *stk_size = stack_top - stack_bottom; 515 516 if (!main) { 517 // If stack and tls intersect, make them non-intersecting. 518 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { 519 CHECK_GT(*tls_addr + *tls_size, *stk_addr); 520 CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size); 521 *stk_size -= *tls_size; 522 *tls_addr = *stk_addr + *stk_size; 523 } 524 } 525 #endif 526 } 527 528 #if !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 529 typedef ElfW(Phdr) Elf_Phdr; 530 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2 531 #define Elf_Phdr XElf32_Phdr 532 #define dl_phdr_info xdl_phdr_info 533 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b)) 534 #endif // !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 535 536 struct DlIteratePhdrData { 537 InternalMmapVectorNoCtor<LoadedModule> *modules; 538 bool first; 539 }; 540 541 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) { 542 DlIteratePhdrData *data = (DlIteratePhdrData*)arg; 543 InternalScopedString module_name(kMaxPathLength); 544 if (data->first) { 545 data->first = false; 546 // First module is the binary itself. 547 ReadBinaryNameCached(module_name.data(), module_name.size()); 548 } else if (info->dlpi_name) { 549 module_name.append("%s", info->dlpi_name); 550 } 551 if (module_name[0] == '\0') 552 return 0; 553 LoadedModule cur_module; 554 cur_module.set(module_name.data(), info->dlpi_addr); 555 for (int i = 0; i < (int)info->dlpi_phnum; i++) { 556 const Elf_Phdr *phdr = &info->dlpi_phdr[i]; 557 if (phdr->p_type == PT_LOAD) { 558 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr; 559 uptr cur_end = cur_beg + phdr->p_memsz; 560 bool executable = phdr->p_flags & PF_X; 561 bool writable = phdr->p_flags & PF_W; 562 cur_module.addAddressRange(cur_beg, cur_end, executable, 563 writable); 564 } 565 } 566 data->modules->push_back(cur_module); 567 return 0; 568 } 569 570 #if SANITIZER_ANDROID && __ANDROID_API__ < 21 571 extern "C" __attribute__((weak)) int dl_iterate_phdr( 572 int (*)(struct dl_phdr_info *, size_t, void *), void *); 573 #endif 574 575 static bool requiresProcmaps() { 576 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22 577 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken. 578 // The runtime check allows the same library to work with 579 // both K and L (and future) Android releases. 580 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1; 581 #else 582 return false; 583 #endif 584 } 585 586 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) { 587 MemoryMappingLayout memory_mapping(/*cache_enabled*/true); 588 memory_mapping.DumpListOfModules(modules); 589 } 590 591 void ListOfModules::init() { 592 clearOrInit(); 593 if (requiresProcmaps()) { 594 procmapsInit(&modules_); 595 } else { 596 DlIteratePhdrData data = {&modules_, true}; 597 dl_iterate_phdr(dl_iterate_phdr_cb, &data); 598 } 599 } 600 601 // When a custom loader is used, dl_iterate_phdr may not contain the full 602 // list of modules. Allow callers to fall back to using procmaps. 603 void ListOfModules::fallbackInit() { 604 if (!requiresProcmaps()) { 605 clearOrInit(); 606 procmapsInit(&modules_); 607 } else { 608 clear(); 609 } 610 } 611 612 // getrusage does not give us the current RSS, only the max RSS. 613 // Still, this is better than nothing if /proc/self/statm is not available 614 // for some reason, e.g. due to a sandbox. 615 static uptr GetRSSFromGetrusage() { 616 struct rusage usage; 617 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox. 618 return 0; 619 return usage.ru_maxrss << 10; // ru_maxrss is in Kb. 620 } 621 622 uptr GetRSS() { 623 if (!common_flags()->can_use_proc_maps_statm) 624 return GetRSSFromGetrusage(); 625 fd_t fd = OpenFile("/proc/self/statm", RdOnly); 626 if (fd == kInvalidFd) 627 return GetRSSFromGetrusage(); 628 char buf[64]; 629 uptr len = internal_read(fd, buf, sizeof(buf) - 1); 630 internal_close(fd); 631 if ((sptr)len <= 0) 632 return 0; 633 buf[len] = 0; 634 // The format of the file is: 635 // 1084 89 69 11 0 79 0 636 // We need the second number which is RSS in pages. 637 char *pos = buf; 638 // Skip the first number. 639 while (*pos >= '0' && *pos <= '9') 640 pos++; 641 // Skip whitespaces. 642 while (!(*pos >= '0' && *pos <= '9') && *pos != 0) 643 pos++; 644 // Read the number. 645 uptr rss = 0; 646 while (*pos >= '0' && *pos <= '9') 647 rss = rss * 10 + *pos++ - '0'; 648 return rss * GetPageSizeCached(); 649 } 650 651 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as 652 // they allocate memory. 653 u32 GetNumberOfCPUs() { 654 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD 655 u32 ncpu; 656 int req[2]; 657 uptr len = sizeof(ncpu); 658 req[0] = CTL_HW; 659 req[1] = HW_NCPU; 660 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0); 661 return ncpu; 662 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__) 663 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't 664 // exist in sched.h. That is the case for toolchains generated with older 665 // NDKs. 666 // This code doesn't work on AArch64 because internal_getdents makes use of 667 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64. 668 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY); 669 if (internal_iserror(fd)) 670 return 0; 671 InternalMmapVector<u8> buffer(4096); 672 uptr bytes_read = buffer.size(); 673 uptr n_cpus = 0; 674 u8 *d_type; 675 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read]; 676 while (true) { 677 if ((u8 *)entry >= &buffer[bytes_read]) { 678 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(), 679 buffer.size()); 680 if (internal_iserror(bytes_read) || !bytes_read) 681 break; 682 entry = (struct linux_dirent *)buffer.data(); 683 } 684 d_type = (u8 *)entry + entry->d_reclen - 1; 685 if (d_type >= &buffer[bytes_read] || 686 (u8 *)&entry->d_name[3] >= &buffer[bytes_read]) 687 break; 688 if (entry->d_ino != 0 && *d_type == DT_DIR) { 689 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' && 690 entry->d_name[2] == 'u' && 691 entry->d_name[3] >= '0' && entry->d_name[3] <= '9') 692 n_cpus++; 693 } 694 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen); 695 } 696 internal_close(fd); 697 return n_cpus; 698 #elif SANITIZER_SOLARIS 699 return sysconf(_SC_NPROCESSORS_ONLN); 700 #else 701 cpu_set_t CPUs; 702 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0); 703 return CPU_COUNT(&CPUs); 704 #endif 705 } 706 707 #if SANITIZER_LINUX 708 709 # if SANITIZER_ANDROID 710 static atomic_uint8_t android_log_initialized; 711 712 void AndroidLogInit() { 713 openlog(GetProcessName(), 0, LOG_USER); 714 atomic_store(&android_log_initialized, 1, memory_order_release); 715 } 716 717 static bool ShouldLogAfterPrintf() { 718 return atomic_load(&android_log_initialized, memory_order_acquire); 719 } 720 721 extern "C" SANITIZER_WEAK_ATTRIBUTE 722 int async_safe_write_log(int pri, const char* tag, const char* msg); 723 extern "C" SANITIZER_WEAK_ATTRIBUTE 724 int __android_log_write(int prio, const char* tag, const char* msg); 725 726 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime. 727 #define SANITIZER_ANDROID_LOG_INFO 4 728 729 // async_safe_write_log is a new public version of __libc_write_log that is 730 // used behind syslog. It is preferable to syslog as it will not do any dynamic 731 // memory allocation or formatting. 732 // If the function is not available, syslog is preferred for L+ (it was broken 733 // pre-L) as __android_log_write triggers a racey behavior with the strncpy 734 // interceptor. Fallback to __android_log_write pre-L. 735 void WriteOneLineToSyslog(const char *s) { 736 if (&async_safe_write_log) { 737 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s); 738 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) { 739 syslog(LOG_INFO, "%s", s); 740 } else { 741 CHECK(&__android_log_write); 742 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s); 743 } 744 } 745 746 extern "C" SANITIZER_WEAK_ATTRIBUTE 747 void android_set_abort_message(const char *); 748 749 void SetAbortMessage(const char *str) { 750 if (&android_set_abort_message) 751 android_set_abort_message(str); 752 } 753 # else 754 void AndroidLogInit() {} 755 756 static bool ShouldLogAfterPrintf() { return true; } 757 758 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); } 759 760 void SetAbortMessage(const char *str) {} 761 # endif // SANITIZER_ANDROID 762 763 void LogMessageOnPrintf(const char *str) { 764 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf()) 765 WriteToSyslog(str); 766 } 767 768 #endif // SANITIZER_LINUX 769 770 #if SANITIZER_LINUX && !SANITIZER_GO 771 // glibc crashes when using clock_gettime from a preinit_array function as the 772 // vDSO function pointers haven't been initialized yet. __progname is 773 // initialized after the vDSO function pointers, so if it exists, is not null 774 // and is not empty, we can use clock_gettime. 775 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname; 776 INLINE bool CanUseVDSO() { 777 // Bionic is safe, it checks for the vDSO function pointers to be initialized. 778 if (SANITIZER_ANDROID) 779 return true; 780 if (&__progname && __progname && *__progname) 781 return true; 782 return false; 783 } 784 785 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling 786 // clock_gettime. real_clock_gettime only exists if clock_gettime is 787 // intercepted, so define it weakly and use it if available. 788 extern "C" SANITIZER_WEAK_ATTRIBUTE 789 int real_clock_gettime(u32 clk_id, void *tp); 790 u64 MonotonicNanoTime() { 791 timespec ts; 792 if (CanUseVDSO()) { 793 if (&real_clock_gettime) 794 real_clock_gettime(CLOCK_MONOTONIC, &ts); 795 else 796 clock_gettime(CLOCK_MONOTONIC, &ts); 797 } else { 798 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 799 } 800 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 801 } 802 #else 803 // Non-Linux & Go always use the syscall. 804 u64 MonotonicNanoTime() { 805 timespec ts; 806 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 807 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 808 } 809 #endif // SANITIZER_LINUX && !SANITIZER_GO 810 811 #if !SANITIZER_OPENBSD 812 void ReExec() { 813 const char *pathname = "/proc/self/exe"; 814 815 #if SANITIZER_NETBSD 816 static const int name[] = { 817 CTL_KERN, 818 KERN_PROC_ARGS, 819 -1, 820 KERN_PROC_PATHNAME, 821 }; 822 char path[400]; 823 uptr len; 824 825 len = sizeof(path); 826 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1) 827 pathname = path; 828 #elif SANITIZER_SOLARIS 829 pathname = getexecname(); 830 CHECK_NE(pathname, NULL); 831 #elif SANITIZER_USE_GETAUXVAL 832 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that 833 // rely on that will fail to load shared libraries. Query AT_EXECFN instead. 834 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN)); 835 #endif 836 837 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron()); 838 int rverrno; 839 CHECK_EQ(internal_iserror(rv, &rverrno), true); 840 Printf("execve failed, errno %d\n", rverrno); 841 Die(); 842 } 843 #endif // !SANITIZER_OPENBSD 844 845 } // namespace __sanitizer 846 847 #endif 848