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_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 #if SANITIZER_NETBSD 32 #define _RTLD_SOURCE // for __lwp_gettcb_fast() / __lwp_getprivate_fast() 33 #endif 34 35 #include <dlfcn.h> // for dlsym() 36 #include <link.h> 37 #include <pthread.h> 38 #include <signal.h> 39 #include <sys/mman.h> 40 #include <sys/resource.h> 41 #include <syslog.h> 42 43 #if !defined(ElfW) 44 #define ElfW(type) Elf_##type 45 #endif 46 47 #if SANITIZER_FREEBSD 48 #include <pthread_np.h> 49 #include <osreldate.h> 50 #include <sys/sysctl.h> 51 #define pthread_getattr_np pthread_attr_get_np 52 #endif 53 54 #if SANITIZER_NETBSD 55 #include <sys/sysctl.h> 56 #include <sys/tls.h> 57 #include <lwp.h> 58 #endif 59 60 #if SANITIZER_SOLARIS 61 #include <stdlib.h> 62 #include <thread.h> 63 #endif 64 65 #if SANITIZER_ANDROID 66 #include <android/api-level.h> 67 #if !defined(CPU_COUNT) && !defined(__aarch64__) 68 #include <dirent.h> 69 #include <fcntl.h> 70 struct __sanitizer::linux_dirent { 71 long d_ino; 72 off_t d_off; 73 unsigned short d_reclen; 74 char d_name[]; 75 }; 76 #endif 77 #endif 78 79 #if !SANITIZER_ANDROID 80 #include <elf.h> 81 #include <unistd.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 if (proc_maps.Error()) { 110 *stack_top = *stack_bottom = 0; 111 return; 112 } 113 MemoryMappedSegment segment; 114 uptr prev_end = 0; 115 while (proc_maps.Next(&segment)) { 116 if ((uptr)&rl < segment.end) break; 117 prev_end = segment.end; 118 } 119 CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end); 120 121 // Get stacksize from rlimit, but clip it so that it does not overlap 122 // with other mappings. 123 uptr stacksize = rl.rlim_cur; 124 if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end; 125 // When running with unlimited stack size, we still want to set some limit. 126 // The unlimited stack size is caused by 'ulimit -s unlimited'. 127 // Also, for some reason, GNU make spawns subprocesses with unlimited stack. 128 if (stacksize > kMaxThreadStackSize) 129 stacksize = kMaxThreadStackSize; 130 *stack_top = segment.end; 131 *stack_bottom = segment.end - stacksize; 132 return; 133 } 134 uptr stacksize = 0; 135 void *stackaddr = nullptr; 136 #if SANITIZER_SOLARIS 137 stack_t ss; 138 CHECK_EQ(thr_stksegment(&ss), 0); 139 stacksize = ss.ss_size; 140 stackaddr = (char *)ss.ss_sp - stacksize; 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_GLIBC && !SANITIZER_GO 188 static uptr g_tls_size; 189 190 #ifdef __i386__ 191 #define CHECK_GET_TLS_STATIC_INFO_VERSION (!__GLIBC_PREREQ(2, 27)) 192 #else 193 #define CHECK_GET_TLS_STATIC_INFO_VERSION 0 194 #endif 195 196 #if CHECK_GET_TLS_STATIC_INFO_VERSION 197 #define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall)) 198 #else 199 #define DL_INTERNAL_FUNCTION 200 #endif 201 202 namespace { 203 struct GetTlsStaticInfoCall { 204 typedef void (*get_tls_func)(size_t*, size_t*); 205 }; 206 struct GetTlsStaticInfoRegparmCall { 207 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION; 208 }; 209 210 template <typename T> 211 void CallGetTls(void* ptr, size_t* size, size_t* align) { 212 typename T::get_tls_func get_tls; 213 CHECK_EQ(sizeof(get_tls), sizeof(ptr)); 214 internal_memcpy(&get_tls, &ptr, sizeof(ptr)); 215 CHECK_NE(get_tls, 0); 216 get_tls(size, align); 217 } 218 219 bool CmpLibcVersion(int major, int minor, int patch) { 220 int ma; 221 int mi; 222 int pa; 223 if (!GetLibcVersion(&ma, &mi, &pa)) 224 return false; 225 if (ma > major) 226 return true; 227 if (ma < major) 228 return false; 229 if (mi > minor) 230 return true; 231 if (mi < minor) 232 return false; 233 return pa >= patch; 234 } 235 236 } // namespace 237 238 void InitTlsSize() { 239 // all current supported platforms have 16 bytes stack alignment 240 const size_t kStackAlign = 16; 241 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); 242 size_t tls_size = 0; 243 size_t tls_align = 0; 244 // On i?86, _dl_get_tls_static_info used to be internal_function, i.e. 245 // __attribute__((regparm(3), stdcall)) before glibc 2.27 and is normal 246 // function in 2.27 and later. 247 if (CHECK_GET_TLS_STATIC_INFO_VERSION && !CmpLibcVersion(2, 27, 0)) 248 CallGetTls<GetTlsStaticInfoRegparmCall>(get_tls_static_info_ptr, 249 &tls_size, &tls_align); 250 else 251 CallGetTls<GetTlsStaticInfoCall>(get_tls_static_info_ptr, 252 &tls_size, &tls_align); 253 if (tls_align < kStackAlign) 254 tls_align = kStackAlign; 255 g_tls_size = RoundUpTo(tls_size, tls_align); 256 } 257 #else 258 void InitTlsSize() { } 259 #endif // SANITIZER_GLIBC && !SANITIZER_GO 260 261 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) || \ 262 defined(__aarch64__) || defined(__powerpc64__) || defined(__s390__) || \ 263 defined(__arm__) || SANITIZER_RISCV64) && \ 264 SANITIZER_LINUX && !SANITIZER_ANDROID 265 // sizeof(struct pthread) from glibc. 266 static atomic_uintptr_t thread_descriptor_size; 267 268 uptr ThreadDescriptorSize() { 269 uptr val = atomic_load_relaxed(&thread_descriptor_size); 270 if (val) 271 return val; 272 #if defined(__x86_64__) || defined(__i386__) || defined(__arm__) 273 int major; 274 int minor; 275 int patch; 276 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 277 /* sizeof(struct pthread) values from various glibc versions. */ 278 if (SANITIZER_X32) 279 val = 1728; // Assume only one particular version for x32. 280 // For ARM sizeof(struct pthread) changed in Glibc 2.23. 281 else if (SANITIZER_ARM) 282 val = minor <= 22 ? 1120 : 1216; 283 else if (minor <= 3) 284 val = FIRST_32_SECOND_64(1104, 1696); 285 else if (minor == 4) 286 val = FIRST_32_SECOND_64(1120, 1728); 287 else if (minor == 5) 288 val = FIRST_32_SECOND_64(1136, 1728); 289 else if (minor <= 9) 290 val = FIRST_32_SECOND_64(1136, 1712); 291 else if (minor == 10) 292 val = FIRST_32_SECOND_64(1168, 1776); 293 else if (minor == 11 || (minor == 12 && patch == 1)) 294 val = FIRST_32_SECOND_64(1168, 2288); 295 else if (minor <= 14) 296 val = FIRST_32_SECOND_64(1168, 2304); 297 else if (minor < 32) // Unknown version 298 val = FIRST_32_SECOND_64(1216, 2304); 299 else // minor == 32 300 val = FIRST_32_SECOND_64(1344, 2496); 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 SANITIZER_RISCV64 306 int major; 307 int minor; 308 int patch; 309 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 310 // TODO: consider adding an optional runtime check for an unknown (untested) 311 // glibc version 312 if (minor <= 28) // WARNING: the highest tested version is 2.29 313 val = 1772; // no guarantees for this one 314 else if (minor <= 31) 315 val = 1772; // tested against glibc 2.29, 2.31 316 else 317 val = 1936; // tested against glibc 2.32 318 } 319 320 #elif defined(__aarch64__) 321 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22. 322 val = 1776; 323 #elif defined(__powerpc64__) 324 val = 1776; // from glibc.ppc64le 2.20-8.fc21 325 #elif defined(__s390__) 326 val = FIRST_32_SECOND_64(1152, 1776); // valid for glibc 2.22 327 #endif 328 if (val) 329 atomic_store_relaxed(&thread_descriptor_size, val); 330 return val; 331 } 332 333 // The offset at which pointer to self is located in the thread descriptor. 334 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16); 335 336 uptr ThreadSelfOffset() { 337 return kThreadSelfOffset; 338 } 339 340 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 341 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb 342 // head structure. It lies before the static tls blocks. 343 static uptr TlsPreTcbSize() { 344 #if defined(__mips__) 345 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 346 #elif defined(__powerpc64__) 347 const uptr kTcbHead = 88; // sizeof (tcbhead_t) 348 #elif SANITIZER_RISCV64 349 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 350 #endif 351 const uptr kTlsAlign = 16; 352 const uptr kTlsPreTcbSize = 353 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign); 354 return kTlsPreTcbSize; 355 } 356 #endif 357 358 uptr ThreadSelf() { 359 uptr descr_addr; 360 #if defined(__i386__) 361 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 362 #elif defined(__x86_64__) 363 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 364 #elif defined(__mips__) 365 // MIPS uses TLS variant I. The thread pointer (in hardware register $29) 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 volatile(".set push;\ 372 .set mips64r2;\ 373 rdhwr %0,$29;\ 374 .set pop" : "=r" (thread_pointer)); 375 descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize(); 376 #elif defined(__aarch64__) || defined(__arm__) 377 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) - 378 ThreadDescriptorSize(); 379 #elif SANITIZER_RISCV64 380 // https://github.com/riscv/riscv-elf-psabi-doc/issues/53 381 uptr thread_pointer = reinterpret_cast<uptr>(__builtin_thread_pointer()); 382 descr_addr = thread_pointer - TlsPreTcbSize(); 383 #elif defined(__s390__) 384 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()); 385 #elif defined(__powerpc64__) 386 // PPC64LE uses TLS variant I. The thread pointer (in GPR 13) 387 // points to the end of the TCB + 0x7000. The pthread_descr structure is 388 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 389 // TCB and the size of pthread_descr. 390 const uptr kTlsTcbOffset = 0x7000; 391 uptr thread_pointer; 392 asm("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset)); 393 descr_addr = thread_pointer - TlsPreTcbSize(); 394 #else 395 #error "unsupported CPU arch" 396 #endif 397 return descr_addr; 398 } 399 #endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX 400 401 #if SANITIZER_FREEBSD 402 static void **ThreadSelfSegbase() { 403 void **segbase = 0; 404 #if defined(__i386__) 405 // sysarch(I386_GET_GSBASE, segbase); 406 __asm __volatile("mov %%gs:0, %0" : "=r" (segbase)); 407 #elif defined(__x86_64__) 408 // sysarch(AMD64_GET_FSBASE, segbase); 409 __asm __volatile("movq %%fs:0, %0" : "=r" (segbase)); 410 #else 411 #error "unsupported CPU arch" 412 #endif 413 return segbase; 414 } 415 416 uptr ThreadSelf() { 417 return (uptr)ThreadSelfSegbase()[2]; 418 } 419 #endif // SANITIZER_FREEBSD 420 421 #if SANITIZER_NETBSD 422 static struct tls_tcb * ThreadSelfTlsTcb() { 423 struct tls_tcb *tcb = nullptr; 424 #ifdef __HAVE___LWP_GETTCB_FAST 425 tcb = (struct tls_tcb *)__lwp_gettcb_fast(); 426 #elif defined(__HAVE___LWP_GETPRIVATE_FAST) 427 tcb = (struct tls_tcb *)__lwp_getprivate_fast(); 428 #endif 429 return tcb; 430 } 431 432 uptr ThreadSelf() { 433 return (uptr)ThreadSelfTlsTcb()->tcb_pthread; 434 } 435 436 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) { 437 const Elf_Phdr *hdr = info->dlpi_phdr; 438 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum; 439 440 for (; hdr != last_hdr; ++hdr) { 441 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) { 442 *(uptr*)data = hdr->p_memsz; 443 break; 444 } 445 } 446 return 0; 447 } 448 #endif // SANITIZER_NETBSD 449 450 #if SANITIZER_ANDROID 451 // Bionic provides this API since S. 452 extern "C" SANITIZER_WEAK_ATTRIBUTE void __libc_get_static_tls_bounds(void **, 453 void **); 454 #endif 455 456 #if !SANITIZER_GO 457 static void GetTls(uptr *addr, uptr *size) { 458 #if SANITIZER_ANDROID 459 if (&__libc_get_static_tls_bounds) { 460 void *start_addr; 461 void *end_addr; 462 __libc_get_static_tls_bounds(&start_addr, &end_addr); 463 *addr = reinterpret_cast<uptr>(start_addr); 464 *size = 465 reinterpret_cast<uptr>(end_addr) - reinterpret_cast<uptr>(start_addr); 466 } else { 467 *addr = 0; 468 *size = 0; 469 } 470 #elif SANITIZER_LINUX 471 #if defined(__x86_64__) || defined(__i386__) || defined(__s390__) 472 *addr = ThreadSelf(); 473 *size = GetTlsSize(); 474 *addr -= *size; 475 *addr += ThreadDescriptorSize(); 476 #elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__) || \ 477 defined(__arm__) || SANITIZER_RISCV64 478 *addr = ThreadSelf(); 479 *size = GetTlsSize(); 480 #else 481 *addr = 0; 482 *size = 0; 483 #endif 484 #elif SANITIZER_FREEBSD 485 void** segbase = ThreadSelfSegbase(); 486 *addr = 0; 487 *size = 0; 488 if (segbase != 0) { 489 // tcbalign = 16 490 // tls_size = round(tls_static_space, tcbalign); 491 // dtv = segbase[1]; 492 // dtv[2] = segbase - tls_static_space; 493 void **dtv = (void**) segbase[1]; 494 *addr = (uptr) dtv[2]; 495 *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]); 496 } 497 #elif SANITIZER_NETBSD 498 struct tls_tcb * const tcb = ThreadSelfTlsTcb(); 499 *addr = 0; 500 *size = 0; 501 if (tcb != 0) { 502 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program). 503 // ld.elf_so hardcodes the index 1. 504 dl_iterate_phdr(GetSizeFromHdr, size); 505 506 if (*size != 0) { 507 // The block has been found and tcb_dtv[1] contains the base address 508 *addr = (uptr)tcb->tcb_dtv[1]; 509 } 510 } 511 #elif SANITIZER_SOLARIS 512 // FIXME 513 *addr = 0; 514 *size = 0; 515 #else 516 #error "Unknown OS" 517 #endif 518 } 519 #endif 520 521 #if !SANITIZER_GO 522 uptr GetTlsSize() { 523 #if SANITIZER_FREEBSD || SANITIZER_ANDROID || SANITIZER_NETBSD || \ 524 SANITIZER_SOLARIS 525 uptr addr, size; 526 GetTls(&addr, &size); 527 return size; 528 #elif SANITIZER_GLIBC 529 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 530 return RoundUpTo(g_tls_size + TlsPreTcbSize(), 16); 531 #else 532 return g_tls_size; 533 #endif 534 #else 535 return 0; 536 #endif 537 } 538 #endif 539 540 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, 541 uptr *tls_addr, uptr *tls_size) { 542 #if SANITIZER_GO 543 // Stub implementation for Go. 544 *stk_addr = *stk_size = *tls_addr = *tls_size = 0; 545 #else 546 GetTls(tls_addr, tls_size); 547 548 uptr stack_top, stack_bottom; 549 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); 550 *stk_addr = stack_bottom; 551 *stk_size = stack_top - stack_bottom; 552 553 if (!main) { 554 // If stack and tls intersect, make them non-intersecting. 555 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { 556 CHECK_GT(*tls_addr + *tls_size, *stk_addr); 557 CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size); 558 *stk_size -= *tls_size; 559 *tls_addr = *stk_addr + *stk_size; 560 } 561 } 562 #endif 563 } 564 565 #if !SANITIZER_FREEBSD 566 typedef ElfW(Phdr) Elf_Phdr; 567 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2 568 #define Elf_Phdr XElf32_Phdr 569 #define dl_phdr_info xdl_phdr_info 570 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b)) 571 #endif // !SANITIZER_FREEBSD 572 573 struct DlIteratePhdrData { 574 InternalMmapVectorNoCtor<LoadedModule> *modules; 575 bool first; 576 }; 577 578 static int AddModuleSegments(const char *module_name, dl_phdr_info *info, 579 InternalMmapVectorNoCtor<LoadedModule> *modules) { 580 if (module_name[0] == '\0') 581 return 0; 582 LoadedModule cur_module; 583 cur_module.set(module_name, info->dlpi_addr); 584 for (int i = 0; i < (int)info->dlpi_phnum; i++) { 585 const Elf_Phdr *phdr = &info->dlpi_phdr[i]; 586 if (phdr->p_type == PT_LOAD) { 587 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr; 588 uptr cur_end = cur_beg + phdr->p_memsz; 589 bool executable = phdr->p_flags & PF_X; 590 bool writable = phdr->p_flags & PF_W; 591 cur_module.addAddressRange(cur_beg, cur_end, executable, 592 writable); 593 } 594 } 595 modules->push_back(cur_module); 596 return 0; 597 } 598 599 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) { 600 DlIteratePhdrData *data = (DlIteratePhdrData *)arg; 601 if (data->first) { 602 InternalMmapVector<char> module_name(kMaxPathLength); 603 data->first = false; 604 // First module is the binary itself. 605 ReadBinaryNameCached(module_name.data(), module_name.size()); 606 return AddModuleSegments(module_name.data(), info, data->modules); 607 } 608 609 if (info->dlpi_name) { 610 InternalScopedString module_name; 611 module_name.append("%s", info->dlpi_name); 612 return AddModuleSegments(module_name.data(), info, data->modules); 613 } 614 615 return 0; 616 } 617 618 #if SANITIZER_ANDROID && __ANDROID_API__ < 21 619 extern "C" __attribute__((weak)) int dl_iterate_phdr( 620 int (*)(struct dl_phdr_info *, size_t, void *), void *); 621 #endif 622 623 static bool requiresProcmaps() { 624 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22 625 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken. 626 // The runtime check allows the same library to work with 627 // both K and L (and future) Android releases. 628 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1; 629 #else 630 return false; 631 #endif 632 } 633 634 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) { 635 MemoryMappingLayout memory_mapping(/*cache_enabled*/true); 636 memory_mapping.DumpListOfModules(modules); 637 } 638 639 void ListOfModules::init() { 640 clearOrInit(); 641 if (requiresProcmaps()) { 642 procmapsInit(&modules_); 643 } else { 644 DlIteratePhdrData data = {&modules_, true}; 645 dl_iterate_phdr(dl_iterate_phdr_cb, &data); 646 } 647 } 648 649 // When a custom loader is used, dl_iterate_phdr may not contain the full 650 // list of modules. Allow callers to fall back to using procmaps. 651 void ListOfModules::fallbackInit() { 652 if (!requiresProcmaps()) { 653 clearOrInit(); 654 procmapsInit(&modules_); 655 } else { 656 clear(); 657 } 658 } 659 660 // getrusage does not give us the current RSS, only the max RSS. 661 // Still, this is better than nothing if /proc/self/statm is not available 662 // for some reason, e.g. due to a sandbox. 663 static uptr GetRSSFromGetrusage() { 664 struct rusage usage; 665 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox. 666 return 0; 667 return usage.ru_maxrss << 10; // ru_maxrss is in Kb. 668 } 669 670 uptr GetRSS() { 671 if (!common_flags()->can_use_proc_maps_statm) 672 return GetRSSFromGetrusage(); 673 fd_t fd = OpenFile("/proc/self/statm", RdOnly); 674 if (fd == kInvalidFd) 675 return GetRSSFromGetrusage(); 676 char buf[64]; 677 uptr len = internal_read(fd, buf, sizeof(buf) - 1); 678 internal_close(fd); 679 if ((sptr)len <= 0) 680 return 0; 681 buf[len] = 0; 682 // The format of the file is: 683 // 1084 89 69 11 0 79 0 684 // We need the second number which is RSS in pages. 685 char *pos = buf; 686 // Skip the first number. 687 while (*pos >= '0' && *pos <= '9') 688 pos++; 689 // Skip whitespaces. 690 while (!(*pos >= '0' && *pos <= '9') && *pos != 0) 691 pos++; 692 // Read the number. 693 uptr rss = 0; 694 while (*pos >= '0' && *pos <= '9') 695 rss = rss * 10 + *pos++ - '0'; 696 return rss * GetPageSizeCached(); 697 } 698 699 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as 700 // they allocate memory. 701 u32 GetNumberOfCPUs() { 702 #if SANITIZER_FREEBSD || SANITIZER_NETBSD 703 u32 ncpu; 704 int req[2]; 705 uptr len = sizeof(ncpu); 706 req[0] = CTL_HW; 707 req[1] = HW_NCPU; 708 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0); 709 return ncpu; 710 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__) 711 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't 712 // exist in sched.h. That is the case for toolchains generated with older 713 // NDKs. 714 // This code doesn't work on AArch64 because internal_getdents makes use of 715 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64. 716 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY); 717 if (internal_iserror(fd)) 718 return 0; 719 InternalMmapVector<u8> buffer(4096); 720 uptr bytes_read = buffer.size(); 721 uptr n_cpus = 0; 722 u8 *d_type; 723 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read]; 724 while (true) { 725 if ((u8 *)entry >= &buffer[bytes_read]) { 726 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(), 727 buffer.size()); 728 if (internal_iserror(bytes_read) || !bytes_read) 729 break; 730 entry = (struct linux_dirent *)buffer.data(); 731 } 732 d_type = (u8 *)entry + entry->d_reclen - 1; 733 if (d_type >= &buffer[bytes_read] || 734 (u8 *)&entry->d_name[3] >= &buffer[bytes_read]) 735 break; 736 if (entry->d_ino != 0 && *d_type == DT_DIR) { 737 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' && 738 entry->d_name[2] == 'u' && 739 entry->d_name[3] >= '0' && entry->d_name[3] <= '9') 740 n_cpus++; 741 } 742 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen); 743 } 744 internal_close(fd); 745 return n_cpus; 746 #elif SANITIZER_SOLARIS 747 return sysconf(_SC_NPROCESSORS_ONLN); 748 #else 749 cpu_set_t CPUs; 750 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0); 751 return CPU_COUNT(&CPUs); 752 #endif 753 } 754 755 #if SANITIZER_LINUX 756 757 #if SANITIZER_ANDROID 758 static atomic_uint8_t android_log_initialized; 759 760 void AndroidLogInit() { 761 openlog(GetProcessName(), 0, LOG_USER); 762 atomic_store(&android_log_initialized, 1, memory_order_release); 763 } 764 765 static bool ShouldLogAfterPrintf() { 766 return atomic_load(&android_log_initialized, memory_order_acquire); 767 } 768 769 extern "C" SANITIZER_WEAK_ATTRIBUTE 770 int async_safe_write_log(int pri, const char* tag, const char* msg); 771 extern "C" SANITIZER_WEAK_ATTRIBUTE 772 int __android_log_write(int prio, const char* tag, const char* msg); 773 774 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime. 775 #define SANITIZER_ANDROID_LOG_INFO 4 776 777 // async_safe_write_log is a new public version of __libc_write_log that is 778 // used behind syslog. It is preferable to syslog as it will not do any dynamic 779 // memory allocation or formatting. 780 // If the function is not available, syslog is preferred for L+ (it was broken 781 // pre-L) as __android_log_write triggers a racey behavior with the strncpy 782 // interceptor. Fallback to __android_log_write pre-L. 783 void WriteOneLineToSyslog(const char *s) { 784 if (&async_safe_write_log) { 785 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s); 786 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) { 787 syslog(LOG_INFO, "%s", s); 788 } else { 789 CHECK(&__android_log_write); 790 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s); 791 } 792 } 793 794 extern "C" SANITIZER_WEAK_ATTRIBUTE 795 void android_set_abort_message(const char *); 796 797 void SetAbortMessage(const char *str) { 798 if (&android_set_abort_message) 799 android_set_abort_message(str); 800 } 801 #else 802 void AndroidLogInit() {} 803 804 static bool ShouldLogAfterPrintf() { return true; } 805 806 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); } 807 808 void SetAbortMessage(const char *str) {} 809 #endif // SANITIZER_ANDROID 810 811 void LogMessageOnPrintf(const char *str) { 812 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf()) 813 WriteToSyslog(str); 814 } 815 816 #endif // SANITIZER_LINUX 817 818 #if SANITIZER_GLIBC && !SANITIZER_GO 819 // glibc crashes when using clock_gettime from a preinit_array function as the 820 // vDSO function pointers haven't been initialized yet. __progname is 821 // initialized after the vDSO function pointers, so if it exists, is not null 822 // and is not empty, we can use clock_gettime. 823 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname; 824 inline bool CanUseVDSO() { return &__progname && __progname && *__progname; } 825 826 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling 827 // clock_gettime. real_clock_gettime only exists if clock_gettime is 828 // intercepted, so define it weakly and use it if available. 829 extern "C" SANITIZER_WEAK_ATTRIBUTE 830 int real_clock_gettime(u32 clk_id, void *tp); 831 u64 MonotonicNanoTime() { 832 timespec ts; 833 if (CanUseVDSO()) { 834 if (&real_clock_gettime) 835 real_clock_gettime(CLOCK_MONOTONIC, &ts); 836 else 837 clock_gettime(CLOCK_MONOTONIC, &ts); 838 } else { 839 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 840 } 841 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 842 } 843 #else 844 // Non-glibc & Go always use the regular function. 845 u64 MonotonicNanoTime() { 846 timespec ts; 847 clock_gettime(CLOCK_MONOTONIC, &ts); 848 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 849 } 850 #endif // SANITIZER_GLIBC && !SANITIZER_GO 851 852 void ReExec() { 853 const char *pathname = "/proc/self/exe"; 854 855 #if SANITIZER_NETBSD 856 static const int name[] = { 857 CTL_KERN, 858 KERN_PROC_ARGS, 859 -1, 860 KERN_PROC_PATHNAME, 861 }; 862 char path[400]; 863 uptr len; 864 865 len = sizeof(path); 866 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1) 867 pathname = path; 868 #elif SANITIZER_SOLARIS 869 pathname = getexecname(); 870 CHECK_NE(pathname, NULL); 871 #elif SANITIZER_USE_GETAUXVAL 872 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that 873 // rely on that will fail to load shared libraries. Query AT_EXECFN instead. 874 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN)); 875 #endif 876 877 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron()); 878 int rverrno; 879 CHECK_EQ(internal_iserror(rv, &rverrno), true); 880 Printf("execve failed, errno %d\n", rverrno); 881 Die(); 882 } 883 884 void UnmapFromTo(uptr from, uptr to) { 885 if (to == from) 886 return; 887 CHECK(to >= from); 888 uptr res = internal_munmap(reinterpret_cast<void *>(from), to - from); 889 if (UNLIKELY(internal_iserror(res))) { 890 Report("ERROR: %s failed to unmap 0x%zx (%zd) bytes at address %p\n", 891 SanitizerToolName, to - from, to - from, (void *)from); 892 CHECK("unable to unmap" && 0); 893 } 894 } 895 896 uptr MapDynamicShadow(uptr shadow_size_bytes, uptr shadow_scale, 897 uptr min_shadow_base_alignment, 898 UNUSED uptr &high_mem_end) { 899 const uptr granularity = GetMmapGranularity(); 900 const uptr alignment = 901 Max<uptr>(granularity << shadow_scale, 1ULL << min_shadow_base_alignment); 902 const uptr left_padding = 903 Max<uptr>(granularity, 1ULL << min_shadow_base_alignment); 904 905 const uptr shadow_size = RoundUpTo(shadow_size_bytes, granularity); 906 const uptr map_size = shadow_size + left_padding + alignment; 907 908 const uptr map_start = (uptr)MmapNoAccess(map_size); 909 CHECK_NE(map_start, ~(uptr)0); 910 911 const uptr shadow_start = RoundUpTo(map_start + left_padding, alignment); 912 913 UnmapFromTo(map_start, shadow_start - left_padding); 914 UnmapFromTo(shadow_start + shadow_size, map_start + map_size); 915 916 return shadow_start; 917 } 918 919 static uptr MmapSharedNoReserve(uptr addr, uptr size) { 920 return internal_mmap( 921 reinterpret_cast<void *>(addr), size, PROT_READ | PROT_WRITE, 922 MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0); 923 } 924 925 static uptr MremapCreateAlias(uptr base_addr, uptr alias_addr, 926 uptr alias_size) { 927 #if SANITIZER_LINUX 928 return internal_mremap(reinterpret_cast<void *>(base_addr), 0, alias_size, 929 MREMAP_MAYMOVE | MREMAP_FIXED, 930 reinterpret_cast<void *>(alias_addr)); 931 #else 932 CHECK(false && "mremap is not supported outside of Linux"); 933 #endif 934 } 935 936 static void CreateAliases(uptr start_addr, uptr alias_size, uptr num_aliases) { 937 uptr total_size = alias_size * num_aliases; 938 uptr mapped = MmapSharedNoReserve(start_addr, total_size); 939 CHECK_EQ(mapped, start_addr); 940 941 for (uptr i = 1; i < num_aliases; ++i) { 942 uptr alias_addr = start_addr + i * alias_size; 943 CHECK_EQ(MremapCreateAlias(start_addr, alias_addr, alias_size), alias_addr); 944 } 945 } 946 947 uptr MapDynamicShadowAndAliases(uptr shadow_size, uptr alias_size, 948 uptr num_aliases, uptr ring_buffer_size) { 949 CHECK_EQ(alias_size & (alias_size - 1), 0); 950 CHECK_EQ(num_aliases & (num_aliases - 1), 0); 951 CHECK_EQ(ring_buffer_size & (ring_buffer_size - 1), 0); 952 953 const uptr granularity = GetMmapGranularity(); 954 shadow_size = RoundUpTo(shadow_size, granularity); 955 CHECK_EQ(shadow_size & (shadow_size - 1), 0); 956 957 const uptr alias_region_size = alias_size * num_aliases; 958 const uptr alignment = 959 2 * Max(Max(shadow_size, alias_region_size), ring_buffer_size); 960 const uptr left_padding = ring_buffer_size; 961 962 const uptr right_size = alignment; 963 const uptr map_size = left_padding + 2 * alignment; 964 965 const uptr map_start = reinterpret_cast<uptr>(MmapNoAccess(map_size)); 966 CHECK_NE(map_start, static_cast<uptr>(-1)); 967 const uptr right_start = RoundUpTo(map_start + left_padding, alignment); 968 969 UnmapFromTo(map_start, right_start - left_padding); 970 UnmapFromTo(right_start + right_size, map_start + map_size); 971 972 CreateAliases(right_start + right_size / 2, alias_size, num_aliases); 973 974 return right_start; 975 } 976 977 void InitializePlatformCommonFlags(CommonFlags *cf) { 978 #if SANITIZER_ANDROID 979 if (&__libc_get_static_tls_bounds == nullptr) 980 cf->detect_leaks = false; 981 #endif 982 } 983 984 } // namespace __sanitizer 985 986 #endif 987