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 // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before 53 // that, it was never implemented. So just define it to zero. 54 #undef MAP_NORESERVE 55 #define MAP_NORESERVE 0 56 #endif 57 58 #if SANITIZER_NETBSD 59 #include <sys/sysctl.h> 60 #include <sys/tls.h> 61 #include <lwp.h> 62 #endif 63 64 #if SANITIZER_SOLARIS 65 #include <stdlib.h> 66 #include <thread.h> 67 #endif 68 69 #if SANITIZER_ANDROID 70 #include <android/api-level.h> 71 #if !defined(CPU_COUNT) && !defined(__aarch64__) 72 #include <dirent.h> 73 #include <fcntl.h> 74 struct __sanitizer::linux_dirent { 75 long d_ino; 76 off_t d_off; 77 unsigned short d_reclen; 78 char d_name[]; 79 }; 80 #endif 81 #endif 82 83 #if !SANITIZER_ANDROID 84 #include <elf.h> 85 #include <unistd.h> 86 #endif 87 88 namespace __sanitizer { 89 90 SANITIZER_WEAK_ATTRIBUTE int 91 real_sigaction(int signum, const void *act, void *oldact); 92 93 int internal_sigaction(int signum, const void *act, void *oldact) { 94 #if !SANITIZER_GO 95 if (&real_sigaction) 96 return real_sigaction(signum, act, oldact); 97 #endif 98 return sigaction(signum, (const struct sigaction *)act, 99 (struct sigaction *)oldact); 100 } 101 102 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top, 103 uptr *stack_bottom) { 104 CHECK(stack_top); 105 CHECK(stack_bottom); 106 if (at_initialization) { 107 // This is the main thread. Libpthread may not be initialized yet. 108 struct rlimit rl; 109 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0); 110 111 // Find the mapping that contains a stack variable. 112 MemoryMappingLayout proc_maps(/*cache_enabled*/true); 113 if (proc_maps.Error()) { 114 *stack_top = *stack_bottom = 0; 115 return; 116 } 117 MemoryMappedSegment segment; 118 uptr prev_end = 0; 119 while (proc_maps.Next(&segment)) { 120 if ((uptr)&rl < segment.end) break; 121 prev_end = segment.end; 122 } 123 CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end); 124 125 // Get stacksize from rlimit, but clip it so that it does not overlap 126 // with other mappings. 127 uptr stacksize = rl.rlim_cur; 128 if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end; 129 // When running with unlimited stack size, we still want to set some limit. 130 // The unlimited stack size is caused by 'ulimit -s unlimited'. 131 // Also, for some reason, GNU make spawns subprocesses with unlimited stack. 132 if (stacksize > kMaxThreadStackSize) 133 stacksize = kMaxThreadStackSize; 134 *stack_top = segment.end; 135 *stack_bottom = segment.end - stacksize; 136 return; 137 } 138 uptr stacksize = 0; 139 void *stackaddr = nullptr; 140 #if SANITIZER_SOLARIS 141 stack_t ss; 142 CHECK_EQ(thr_stksegment(&ss), 0); 143 stacksize = ss.ss_size; 144 stackaddr = (char *)ss.ss_sp - stacksize; 145 #else // !SANITIZER_SOLARIS 146 pthread_attr_t attr; 147 pthread_attr_init(&attr); 148 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0); 149 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize); 150 pthread_attr_destroy(&attr); 151 #endif // SANITIZER_SOLARIS 152 153 *stack_top = (uptr)stackaddr + stacksize; 154 *stack_bottom = (uptr)stackaddr; 155 } 156 157 #if !SANITIZER_GO 158 bool SetEnv(const char *name, const char *value) { 159 void *f = dlsym(RTLD_NEXT, "setenv"); 160 if (!f) 161 return false; 162 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite); 163 setenv_ft setenv_f; 164 CHECK_EQ(sizeof(setenv_f), sizeof(f)); 165 internal_memcpy(&setenv_f, &f, sizeof(f)); 166 return setenv_f(name, value, 1) == 0; 167 } 168 #endif 169 170 __attribute__((unused)) static bool GetLibcVersion(int *major, int *minor, 171 int *patch) { 172 #ifdef _CS_GNU_LIBC_VERSION 173 char buf[64]; 174 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf)); 175 if (len >= sizeof(buf)) 176 return false; 177 buf[len] = 0; 178 static const char kGLibC[] = "glibc "; 179 if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0) 180 return false; 181 const char *p = buf + sizeof(kGLibC) - 1; 182 *major = internal_simple_strtoll(p, &p, 10); 183 *minor = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 184 *patch = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 185 return true; 186 #else 187 return false; 188 #endif 189 } 190 191 #if SANITIZER_GLIBC && !SANITIZER_GO 192 static uptr g_tls_size; 193 194 #ifdef __i386__ 195 #define CHECK_GET_TLS_STATIC_INFO_VERSION (!__GLIBC_PREREQ(2, 27)) 196 #else 197 #define CHECK_GET_TLS_STATIC_INFO_VERSION 0 198 #endif 199 200 #if CHECK_GET_TLS_STATIC_INFO_VERSION 201 #define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall)) 202 #else 203 #define DL_INTERNAL_FUNCTION 204 #endif 205 206 namespace { 207 struct GetTlsStaticInfoCall { 208 typedef void (*get_tls_func)(size_t*, size_t*); 209 }; 210 struct GetTlsStaticInfoRegparmCall { 211 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION; 212 }; 213 214 template <typename T> 215 void CallGetTls(void* ptr, size_t* size, size_t* align) { 216 typename T::get_tls_func get_tls; 217 CHECK_EQ(sizeof(get_tls), sizeof(ptr)); 218 internal_memcpy(&get_tls, &ptr, sizeof(ptr)); 219 CHECK_NE(get_tls, 0); 220 get_tls(size, align); 221 } 222 223 bool CmpLibcVersion(int major, int minor, int patch) { 224 int ma; 225 int mi; 226 int pa; 227 if (!GetLibcVersion(&ma, &mi, &pa)) 228 return false; 229 if (ma > major) 230 return true; 231 if (ma < major) 232 return false; 233 if (mi > minor) 234 return true; 235 if (mi < minor) 236 return false; 237 return pa >= patch; 238 } 239 240 } // namespace 241 242 void InitTlsSize() { 243 // all current supported platforms have 16 bytes stack alignment 244 const size_t kStackAlign = 16; 245 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); 246 size_t tls_size = 0; 247 size_t tls_align = 0; 248 // On i?86, _dl_get_tls_static_info used to be internal_function, i.e. 249 // __attribute__((regparm(3), stdcall)) before glibc 2.27 and is normal 250 // function in 2.27 and later. 251 if (CHECK_GET_TLS_STATIC_INFO_VERSION && !CmpLibcVersion(2, 27, 0)) 252 CallGetTls<GetTlsStaticInfoRegparmCall>(get_tls_static_info_ptr, 253 &tls_size, &tls_align); 254 else 255 CallGetTls<GetTlsStaticInfoCall>(get_tls_static_info_ptr, 256 &tls_size, &tls_align); 257 if (tls_align < kStackAlign) 258 tls_align = kStackAlign; 259 g_tls_size = RoundUpTo(tls_size, tls_align); 260 } 261 #else 262 void InitTlsSize() { } 263 #endif // SANITIZER_GLIBC && !SANITIZER_GO 264 265 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) || \ 266 defined(__aarch64__) || defined(__powerpc64__) || defined(__s390__) || \ 267 defined(__arm__) || SANITIZER_RISCV64) && \ 268 SANITIZER_LINUX && !SANITIZER_ANDROID 269 // sizeof(struct pthread) from glibc. 270 static atomic_uintptr_t thread_descriptor_size; 271 272 uptr ThreadDescriptorSize() { 273 uptr val = atomic_load_relaxed(&thread_descriptor_size); 274 if (val) 275 return val; 276 #if defined(__x86_64__) || defined(__i386__) || defined(__arm__) 277 int major; 278 int minor; 279 int patch; 280 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 281 /* sizeof(struct pthread) values from various glibc versions. */ 282 if (SANITIZER_X32) 283 val = 1728; // Assume only one particular version for x32. 284 // For ARM sizeof(struct pthread) changed in Glibc 2.23. 285 else if (SANITIZER_ARM) 286 val = minor <= 22 ? 1120 : 1216; 287 else if (minor <= 3) 288 val = FIRST_32_SECOND_64(1104, 1696); 289 else if (minor == 4) 290 val = FIRST_32_SECOND_64(1120, 1728); 291 else if (minor == 5) 292 val = FIRST_32_SECOND_64(1136, 1728); 293 else if (minor <= 9) 294 val = FIRST_32_SECOND_64(1136, 1712); 295 else if (minor == 10) 296 val = FIRST_32_SECOND_64(1168, 1776); 297 else if (minor == 11 || (minor == 12 && patch == 1)) 298 val = FIRST_32_SECOND_64(1168, 2288); 299 else if (minor <= 14) 300 val = FIRST_32_SECOND_64(1168, 2304); 301 else if (minor < 32) // Unknown version 302 val = FIRST_32_SECOND_64(1216, 2304); 303 else // minor == 32 304 val = FIRST_32_SECOND_64(1344, 2496); 305 } 306 #elif defined(__mips__) 307 // TODO(sagarthakur): add more values as per different glibc versions. 308 val = FIRST_32_SECOND_64(1152, 1776); 309 #elif SANITIZER_RISCV64 310 int major; 311 int minor; 312 int patch; 313 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 314 // TODO: consider adding an optional runtime check for an unknown (untested) 315 // glibc version 316 if (minor <= 28) // WARNING: the highest tested version is 2.29 317 val = 1772; // no guarantees for this one 318 else if (minor <= 31) 319 val = 1772; // tested against glibc 2.29, 2.31 320 else 321 val = 1936; // tested against glibc 2.32 322 } 323 324 #elif defined(__aarch64__) 325 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22. 326 val = 1776; 327 #elif defined(__powerpc64__) 328 val = 1776; // from glibc.ppc64le 2.20-8.fc21 329 #elif defined(__s390__) 330 val = FIRST_32_SECOND_64(1152, 1776); // valid for glibc 2.22 331 #endif 332 if (val) 333 atomic_store_relaxed(&thread_descriptor_size, val); 334 return val; 335 } 336 337 // The offset at which pointer to self is located in the thread descriptor. 338 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16); 339 340 uptr ThreadSelfOffset() { 341 return kThreadSelfOffset; 342 } 343 344 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 345 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb 346 // head structure. It lies before the static tls blocks. 347 static uptr TlsPreTcbSize() { 348 #if defined(__mips__) 349 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 350 #elif defined(__powerpc64__) 351 const uptr kTcbHead = 88; // sizeof (tcbhead_t) 352 #elif SANITIZER_RISCV64 353 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 354 #endif 355 const uptr kTlsAlign = 16; 356 const uptr kTlsPreTcbSize = 357 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign); 358 return kTlsPreTcbSize; 359 } 360 #endif 361 362 uptr ThreadSelf() { 363 uptr descr_addr; 364 #if defined(__i386__) 365 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 366 #elif defined(__x86_64__) 367 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 368 #elif defined(__mips__) 369 // MIPS uses TLS variant I. The thread pointer (in hardware register $29) 370 // points to the end of the TCB + 0x7000. The pthread_descr structure is 371 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 372 // TCB and the size of pthread_descr. 373 const uptr kTlsTcbOffset = 0x7000; 374 uptr thread_pointer; 375 asm volatile(".set push;\ 376 .set mips64r2;\ 377 rdhwr %0,$29;\ 378 .set pop" : "=r" (thread_pointer)); 379 descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize(); 380 #elif defined(__aarch64__) || defined(__arm__) 381 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) - 382 ThreadDescriptorSize(); 383 #elif SANITIZER_RISCV64 384 // https://github.com/riscv/riscv-elf-psabi-doc/issues/53 385 uptr thread_pointer = reinterpret_cast<uptr>(__builtin_thread_pointer()); 386 descr_addr = thread_pointer - TlsPreTcbSize(); 387 #elif defined(__s390__) 388 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()); 389 #elif defined(__powerpc64__) 390 // PPC64LE uses TLS variant I. The thread pointer (in GPR 13) 391 // points to the end of the TCB + 0x7000. The pthread_descr structure is 392 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 393 // TCB and the size of pthread_descr. 394 const uptr kTlsTcbOffset = 0x7000; 395 uptr thread_pointer; 396 asm("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset)); 397 descr_addr = thread_pointer - TlsPreTcbSize(); 398 #else 399 #error "unsupported CPU arch" 400 #endif 401 return descr_addr; 402 } 403 #endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX 404 405 #if SANITIZER_FREEBSD 406 static void **ThreadSelfSegbase() { 407 void **segbase = 0; 408 #if defined(__i386__) 409 // sysarch(I386_GET_GSBASE, segbase); 410 __asm __volatile("mov %%gs:0, %0" : "=r" (segbase)); 411 #elif defined(__x86_64__) 412 // sysarch(AMD64_GET_FSBASE, segbase); 413 __asm __volatile("movq %%fs:0, %0" : "=r" (segbase)); 414 #else 415 #error "unsupported CPU arch" 416 #endif 417 return segbase; 418 } 419 420 uptr ThreadSelf() { 421 return (uptr)ThreadSelfSegbase()[2]; 422 } 423 #endif // SANITIZER_FREEBSD 424 425 #if SANITIZER_NETBSD 426 static struct tls_tcb * ThreadSelfTlsTcb() { 427 struct tls_tcb *tcb = nullptr; 428 #ifdef __HAVE___LWP_GETTCB_FAST 429 tcb = (struct tls_tcb *)__lwp_gettcb_fast(); 430 #elif defined(__HAVE___LWP_GETPRIVATE_FAST) 431 tcb = (struct tls_tcb *)__lwp_getprivate_fast(); 432 #endif 433 return tcb; 434 } 435 436 uptr ThreadSelf() { 437 return (uptr)ThreadSelfTlsTcb()->tcb_pthread; 438 } 439 440 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) { 441 const Elf_Phdr *hdr = info->dlpi_phdr; 442 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum; 443 444 for (; hdr != last_hdr; ++hdr) { 445 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) { 446 *(uptr*)data = hdr->p_memsz; 447 break; 448 } 449 } 450 return 0; 451 } 452 #endif // SANITIZER_NETBSD 453 454 #if SANITIZER_ANDROID 455 // Bionic provides this API since S. 456 extern "C" SANITIZER_WEAK_ATTRIBUTE void __libc_get_static_tls_bounds(void **, 457 void **); 458 #endif 459 460 #if !SANITIZER_GO 461 static void GetTls(uptr *addr, uptr *size) { 462 #if SANITIZER_ANDROID 463 if (&__libc_get_static_tls_bounds) { 464 void *start_addr; 465 void *end_addr; 466 __libc_get_static_tls_bounds(&start_addr, &end_addr); 467 *addr = reinterpret_cast<uptr>(start_addr); 468 *size = 469 reinterpret_cast<uptr>(end_addr) - reinterpret_cast<uptr>(start_addr); 470 } else { 471 *addr = 0; 472 *size = 0; 473 } 474 #elif SANITIZER_LINUX 475 #if defined(__x86_64__) || defined(__i386__) || defined(__s390__) 476 *addr = ThreadSelf(); 477 *size = GetTlsSize(); 478 *addr -= *size; 479 *addr += ThreadDescriptorSize(); 480 #elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__) || \ 481 defined(__arm__) || SANITIZER_RISCV64 482 *addr = ThreadSelf(); 483 *size = GetTlsSize(); 484 #else 485 *addr = 0; 486 *size = 0; 487 #endif 488 #elif SANITIZER_FREEBSD 489 void** segbase = ThreadSelfSegbase(); 490 *addr = 0; 491 *size = 0; 492 if (segbase != 0) { 493 // tcbalign = 16 494 // tls_size = round(tls_static_space, tcbalign); 495 // dtv = segbase[1]; 496 // dtv[2] = segbase - tls_static_space; 497 void **dtv = (void**) segbase[1]; 498 *addr = (uptr) dtv[2]; 499 *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]); 500 } 501 #elif SANITIZER_NETBSD 502 struct tls_tcb * const tcb = ThreadSelfTlsTcb(); 503 *addr = 0; 504 *size = 0; 505 if (tcb != 0) { 506 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program). 507 // ld.elf_so hardcodes the index 1. 508 dl_iterate_phdr(GetSizeFromHdr, size); 509 510 if (*size != 0) { 511 // The block has been found and tcb_dtv[1] contains the base address 512 *addr = (uptr)tcb->tcb_dtv[1]; 513 } 514 } 515 #elif SANITIZER_SOLARIS 516 // FIXME 517 *addr = 0; 518 *size = 0; 519 #else 520 #error "Unknown OS" 521 #endif 522 } 523 #endif 524 525 #if !SANITIZER_GO 526 uptr GetTlsSize() { 527 #if SANITIZER_FREEBSD || SANITIZER_ANDROID || SANITIZER_NETBSD || \ 528 SANITIZER_SOLARIS 529 uptr addr, size; 530 GetTls(&addr, &size); 531 return size; 532 #elif SANITIZER_GLIBC 533 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 534 return RoundUpTo(g_tls_size + TlsPreTcbSize(), 16); 535 #else 536 return g_tls_size; 537 #endif 538 #else 539 return 0; 540 #endif 541 } 542 #endif 543 544 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, 545 uptr *tls_addr, uptr *tls_size) { 546 #if SANITIZER_GO 547 // Stub implementation for Go. 548 *stk_addr = *stk_size = *tls_addr = *tls_size = 0; 549 #else 550 GetTls(tls_addr, tls_size); 551 552 uptr stack_top, stack_bottom; 553 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); 554 *stk_addr = stack_bottom; 555 *stk_size = stack_top - stack_bottom; 556 557 if (!main) { 558 // If stack and tls intersect, make them non-intersecting. 559 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { 560 CHECK_GT(*tls_addr + *tls_size, *stk_addr); 561 CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size); 562 *stk_size -= *tls_size; 563 *tls_addr = *stk_addr + *stk_size; 564 } 565 } 566 #endif 567 } 568 569 #if !SANITIZER_FREEBSD 570 typedef ElfW(Phdr) Elf_Phdr; 571 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2 572 #define Elf_Phdr XElf32_Phdr 573 #define dl_phdr_info xdl_phdr_info 574 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b)) 575 #endif // !SANITIZER_FREEBSD 576 577 struct DlIteratePhdrData { 578 InternalMmapVectorNoCtor<LoadedModule> *modules; 579 bool first; 580 }; 581 582 static int AddModuleSegments(const char *module_name, dl_phdr_info *info, 583 InternalMmapVectorNoCtor<LoadedModule> *modules) { 584 if (module_name[0] == '\0') 585 return 0; 586 LoadedModule cur_module; 587 cur_module.set(module_name, info->dlpi_addr); 588 for (int i = 0; i < (int)info->dlpi_phnum; i++) { 589 const Elf_Phdr *phdr = &info->dlpi_phdr[i]; 590 if (phdr->p_type == PT_LOAD) { 591 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr; 592 uptr cur_end = cur_beg + phdr->p_memsz; 593 bool executable = phdr->p_flags & PF_X; 594 bool writable = phdr->p_flags & PF_W; 595 cur_module.addAddressRange(cur_beg, cur_end, executable, 596 writable); 597 } 598 } 599 modules->push_back(cur_module); 600 return 0; 601 } 602 603 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) { 604 DlIteratePhdrData *data = (DlIteratePhdrData *)arg; 605 if (data->first) { 606 InternalMmapVector<char> module_name(kMaxPathLength); 607 data->first = false; 608 // First module is the binary itself. 609 ReadBinaryNameCached(module_name.data(), module_name.size()); 610 return AddModuleSegments(module_name.data(), info, data->modules); 611 } 612 613 if (info->dlpi_name) { 614 InternalScopedString module_name; 615 module_name.append("%s", info->dlpi_name); 616 return AddModuleSegments(module_name.data(), info, data->modules); 617 } 618 619 return 0; 620 } 621 622 #if SANITIZER_ANDROID && __ANDROID_API__ < 21 623 extern "C" __attribute__((weak)) int dl_iterate_phdr( 624 int (*)(struct dl_phdr_info *, size_t, void *), void *); 625 #endif 626 627 static bool requiresProcmaps() { 628 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22 629 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken. 630 // The runtime check allows the same library to work with 631 // both K and L (and future) Android releases. 632 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1; 633 #else 634 return false; 635 #endif 636 } 637 638 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) { 639 MemoryMappingLayout memory_mapping(/*cache_enabled*/true); 640 memory_mapping.DumpListOfModules(modules); 641 } 642 643 void ListOfModules::init() { 644 clearOrInit(); 645 if (requiresProcmaps()) { 646 procmapsInit(&modules_); 647 } else { 648 DlIteratePhdrData data = {&modules_, true}; 649 dl_iterate_phdr(dl_iterate_phdr_cb, &data); 650 } 651 } 652 653 // When a custom loader is used, dl_iterate_phdr may not contain the full 654 // list of modules. Allow callers to fall back to using procmaps. 655 void ListOfModules::fallbackInit() { 656 if (!requiresProcmaps()) { 657 clearOrInit(); 658 procmapsInit(&modules_); 659 } else { 660 clear(); 661 } 662 } 663 664 // getrusage does not give us the current RSS, only the max RSS. 665 // Still, this is better than nothing if /proc/self/statm is not available 666 // for some reason, e.g. due to a sandbox. 667 static uptr GetRSSFromGetrusage() { 668 struct rusage usage; 669 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox. 670 return 0; 671 return usage.ru_maxrss << 10; // ru_maxrss is in Kb. 672 } 673 674 uptr GetRSS() { 675 if (!common_flags()->can_use_proc_maps_statm) 676 return GetRSSFromGetrusage(); 677 fd_t fd = OpenFile("/proc/self/statm", RdOnly); 678 if (fd == kInvalidFd) 679 return GetRSSFromGetrusage(); 680 char buf[64]; 681 uptr len = internal_read(fd, buf, sizeof(buf) - 1); 682 internal_close(fd); 683 if ((sptr)len <= 0) 684 return 0; 685 buf[len] = 0; 686 // The format of the file is: 687 // 1084 89 69 11 0 79 0 688 // We need the second number which is RSS in pages. 689 char *pos = buf; 690 // Skip the first number. 691 while (*pos >= '0' && *pos <= '9') 692 pos++; 693 // Skip whitespaces. 694 while (!(*pos >= '0' && *pos <= '9') && *pos != 0) 695 pos++; 696 // Read the number. 697 uptr rss = 0; 698 while (*pos >= '0' && *pos <= '9') 699 rss = rss * 10 + *pos++ - '0'; 700 return rss * GetPageSizeCached(); 701 } 702 703 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as 704 // they allocate memory. 705 u32 GetNumberOfCPUs() { 706 #if SANITIZER_FREEBSD || SANITIZER_NETBSD 707 u32 ncpu; 708 int req[2]; 709 uptr len = sizeof(ncpu); 710 req[0] = CTL_HW; 711 req[1] = HW_NCPU; 712 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0); 713 return ncpu; 714 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__) 715 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't 716 // exist in sched.h. That is the case for toolchains generated with older 717 // NDKs. 718 // This code doesn't work on AArch64 because internal_getdents makes use of 719 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64. 720 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY); 721 if (internal_iserror(fd)) 722 return 0; 723 InternalMmapVector<u8> buffer(4096); 724 uptr bytes_read = buffer.size(); 725 uptr n_cpus = 0; 726 u8 *d_type; 727 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read]; 728 while (true) { 729 if ((u8 *)entry >= &buffer[bytes_read]) { 730 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(), 731 buffer.size()); 732 if (internal_iserror(bytes_read) || !bytes_read) 733 break; 734 entry = (struct linux_dirent *)buffer.data(); 735 } 736 d_type = (u8 *)entry + entry->d_reclen - 1; 737 if (d_type >= &buffer[bytes_read] || 738 (u8 *)&entry->d_name[3] >= &buffer[bytes_read]) 739 break; 740 if (entry->d_ino != 0 && *d_type == DT_DIR) { 741 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' && 742 entry->d_name[2] == 'u' && 743 entry->d_name[3] >= '0' && entry->d_name[3] <= '9') 744 n_cpus++; 745 } 746 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen); 747 } 748 internal_close(fd); 749 return n_cpus; 750 #elif SANITIZER_SOLARIS 751 return sysconf(_SC_NPROCESSORS_ONLN); 752 #else 753 cpu_set_t CPUs; 754 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0); 755 return CPU_COUNT(&CPUs); 756 #endif 757 } 758 759 #if SANITIZER_LINUX 760 761 #if SANITIZER_ANDROID 762 static atomic_uint8_t android_log_initialized; 763 764 void AndroidLogInit() { 765 openlog(GetProcessName(), 0, LOG_USER); 766 atomic_store(&android_log_initialized, 1, memory_order_release); 767 } 768 769 static bool ShouldLogAfterPrintf() { 770 return atomic_load(&android_log_initialized, memory_order_acquire); 771 } 772 773 extern "C" SANITIZER_WEAK_ATTRIBUTE 774 int async_safe_write_log(int pri, const char* tag, const char* msg); 775 extern "C" SANITIZER_WEAK_ATTRIBUTE 776 int __android_log_write(int prio, const char* tag, const char* msg); 777 778 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime. 779 #define SANITIZER_ANDROID_LOG_INFO 4 780 781 // async_safe_write_log is a new public version of __libc_write_log that is 782 // used behind syslog. It is preferable to syslog as it will not do any dynamic 783 // memory allocation or formatting. 784 // If the function is not available, syslog is preferred for L+ (it was broken 785 // pre-L) as __android_log_write triggers a racey behavior with the strncpy 786 // interceptor. Fallback to __android_log_write pre-L. 787 void WriteOneLineToSyslog(const char *s) { 788 if (&async_safe_write_log) { 789 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s); 790 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) { 791 syslog(LOG_INFO, "%s", s); 792 } else { 793 CHECK(&__android_log_write); 794 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s); 795 } 796 } 797 798 extern "C" SANITIZER_WEAK_ATTRIBUTE 799 void android_set_abort_message(const char *); 800 801 void SetAbortMessage(const char *str) { 802 if (&android_set_abort_message) 803 android_set_abort_message(str); 804 } 805 #else 806 void AndroidLogInit() {} 807 808 static bool ShouldLogAfterPrintf() { return true; } 809 810 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); } 811 812 void SetAbortMessage(const char *str) {} 813 #endif // SANITIZER_ANDROID 814 815 void LogMessageOnPrintf(const char *str) { 816 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf()) 817 WriteToSyslog(str); 818 } 819 820 #endif // SANITIZER_LINUX 821 822 #if SANITIZER_GLIBC && !SANITIZER_GO 823 // glibc crashes when using clock_gettime from a preinit_array function as the 824 // vDSO function pointers haven't been initialized yet. __progname is 825 // initialized after the vDSO function pointers, so if it exists, is not null 826 // and is not empty, we can use clock_gettime. 827 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname; 828 inline bool CanUseVDSO() { return &__progname && __progname && *__progname; } 829 830 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling 831 // clock_gettime. real_clock_gettime only exists if clock_gettime is 832 // intercepted, so define it weakly and use it if available. 833 extern "C" SANITIZER_WEAK_ATTRIBUTE 834 int real_clock_gettime(u32 clk_id, void *tp); 835 u64 MonotonicNanoTime() { 836 timespec ts; 837 if (CanUseVDSO()) { 838 if (&real_clock_gettime) 839 real_clock_gettime(CLOCK_MONOTONIC, &ts); 840 else 841 clock_gettime(CLOCK_MONOTONIC, &ts); 842 } else { 843 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 844 } 845 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 846 } 847 #else 848 // Non-glibc & Go always use the regular function. 849 u64 MonotonicNanoTime() { 850 timespec ts; 851 clock_gettime(CLOCK_MONOTONIC, &ts); 852 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 853 } 854 #endif // SANITIZER_GLIBC && !SANITIZER_GO 855 856 void ReExec() { 857 const char *pathname = "/proc/self/exe"; 858 859 #if SANITIZER_NETBSD 860 static const int name[] = { 861 CTL_KERN, 862 KERN_PROC_ARGS, 863 -1, 864 KERN_PROC_PATHNAME, 865 }; 866 char path[400]; 867 uptr len; 868 869 len = sizeof(path); 870 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1) 871 pathname = path; 872 #elif SANITIZER_SOLARIS 873 pathname = getexecname(); 874 CHECK_NE(pathname, NULL); 875 #elif SANITIZER_USE_GETAUXVAL 876 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that 877 // rely on that will fail to load shared libraries. Query AT_EXECFN instead. 878 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN)); 879 #endif 880 881 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron()); 882 int rverrno; 883 CHECK_EQ(internal_iserror(rv, &rverrno), true); 884 Printf("execve failed, errno %d\n", rverrno); 885 Die(); 886 } 887 888 void UnmapFromTo(uptr from, uptr to) { 889 if (to == from) 890 return; 891 CHECK(to >= from); 892 uptr res = internal_munmap(reinterpret_cast<void *>(from), to - from); 893 if (UNLIKELY(internal_iserror(res))) { 894 Report("ERROR: %s failed to unmap 0x%zx (%zd) bytes at address %p\n", 895 SanitizerToolName, to - from, to - from, (void *)from); 896 CHECK("unable to unmap" && 0); 897 } 898 } 899 900 uptr MapDynamicShadow(uptr shadow_size_bytes, uptr shadow_scale, 901 uptr min_shadow_base_alignment, 902 UNUSED uptr &high_mem_end) { 903 const uptr granularity = GetMmapGranularity(); 904 const uptr alignment = 905 Max<uptr>(granularity << shadow_scale, 1ULL << min_shadow_base_alignment); 906 const uptr left_padding = 907 Max<uptr>(granularity, 1ULL << min_shadow_base_alignment); 908 909 const uptr shadow_size = RoundUpTo(shadow_size_bytes, granularity); 910 const uptr map_size = shadow_size + left_padding + alignment; 911 912 const uptr map_start = (uptr)MmapNoAccess(map_size); 913 CHECK_NE(map_start, ~(uptr)0); 914 915 const uptr shadow_start = RoundUpTo(map_start + left_padding, alignment); 916 917 UnmapFromTo(map_start, shadow_start - left_padding); 918 UnmapFromTo(shadow_start + shadow_size, map_start + map_size); 919 920 return shadow_start; 921 } 922 923 static uptr MmapSharedNoReserve(uptr addr, uptr size) { 924 return internal_mmap( 925 reinterpret_cast<void *>(addr), size, PROT_READ | PROT_WRITE, 926 MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0); 927 } 928 929 static uptr MremapCreateAlias(uptr base_addr, uptr alias_addr, 930 uptr alias_size) { 931 #if SANITIZER_LINUX 932 return internal_mremap(reinterpret_cast<void *>(base_addr), 0, alias_size, 933 MREMAP_MAYMOVE | MREMAP_FIXED, 934 reinterpret_cast<void *>(alias_addr)); 935 #else 936 CHECK(false && "mremap is not supported outside of Linux"); 937 return 0; 938 #endif 939 } 940 941 static void CreateAliases(uptr start_addr, uptr alias_size, uptr num_aliases) { 942 uptr total_size = alias_size * num_aliases; 943 uptr mapped = MmapSharedNoReserve(start_addr, total_size); 944 CHECK_EQ(mapped, start_addr); 945 946 for (uptr i = 1; i < num_aliases; ++i) { 947 uptr alias_addr = start_addr + i * alias_size; 948 CHECK_EQ(MremapCreateAlias(start_addr, alias_addr, alias_size), alias_addr); 949 } 950 } 951 952 uptr MapDynamicShadowAndAliases(uptr shadow_size, uptr alias_size, 953 uptr num_aliases, uptr ring_buffer_size) { 954 CHECK_EQ(alias_size & (alias_size - 1), 0); 955 CHECK_EQ(num_aliases & (num_aliases - 1), 0); 956 CHECK_EQ(ring_buffer_size & (ring_buffer_size - 1), 0); 957 958 const uptr granularity = GetMmapGranularity(); 959 shadow_size = RoundUpTo(shadow_size, granularity); 960 CHECK_EQ(shadow_size & (shadow_size - 1), 0); 961 962 const uptr alias_region_size = alias_size * num_aliases; 963 const uptr alignment = 964 2 * Max(Max(shadow_size, alias_region_size), ring_buffer_size); 965 const uptr left_padding = ring_buffer_size; 966 967 const uptr right_size = alignment; 968 const uptr map_size = left_padding + 2 * alignment; 969 970 const uptr map_start = reinterpret_cast<uptr>(MmapNoAccess(map_size)); 971 CHECK_NE(map_start, static_cast<uptr>(-1)); 972 const uptr right_start = RoundUpTo(map_start + left_padding, alignment); 973 974 UnmapFromTo(map_start, right_start - left_padding); 975 UnmapFromTo(right_start + right_size, map_start + map_size); 976 977 CreateAliases(right_start + right_size / 2, alias_size, num_aliases); 978 979 return right_start; 980 } 981 982 void InitializePlatformCommonFlags(CommonFlags *cf) { 983 #if SANITIZER_ANDROID 984 if (&__libc_get_static_tls_bounds == nullptr) 985 cf->detect_leaks = false; 986 #endif 987 } 988 989 } // namespace __sanitizer 990 991 #endif 992