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