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 // True if we can use dlpi_tls_data. glibc before 2.25 may leave NULL (BZ 192 // #19826) so dlpi_tls_data cannot be used. 193 // 194 // musl before 1.2.3 and FreeBSD as of 12.2 incorrectly set dlpi_tls_data to 195 // the TLS initialization image 196 // https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=254774 197 __attribute__((unused)) static int g_use_dlpi_tls_data; 198 199 #if SANITIZER_GLIBC && !SANITIZER_GO 200 __attribute__((unused)) static size_t g_tls_size; 201 void InitTlsSize() { 202 int major, minor, patch; 203 g_use_dlpi_tls_data = 204 GetLibcVersion(&major, &minor, &patch) && major == 2 && minor >= 25; 205 206 #if defined(__aarch64__) || defined(__x86_64__) || defined(__powerpc64__) 207 void *get_tls_static_info = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); 208 size_t tls_align; 209 ((void (*)(size_t *, size_t *))get_tls_static_info)(&g_tls_size, &tls_align); 210 #endif 211 } 212 #else 213 void InitTlsSize() { } 214 #endif // SANITIZER_GLIBC && !SANITIZER_GO 215 216 // On glibc x86_64, ThreadDescriptorSize() needs to be precise due to the usage 217 // of g_tls_size. On other targets, ThreadDescriptorSize() is only used by lsan 218 // to get the pointer to thread-specific data keys in the thread control block. 219 #if (SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_SOLARIS) && \ 220 !SANITIZER_ANDROID && !SANITIZER_GO 221 // sizeof(struct pthread) from glibc. 222 static atomic_uintptr_t thread_descriptor_size; 223 224 static uptr ThreadDescriptorSizeFallback() { 225 uptr val = 0; 226 #if defined(__x86_64__) || defined(__i386__) || defined(__arm__) 227 int major; 228 int minor; 229 int patch; 230 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 231 /* sizeof(struct pthread) values from various glibc versions. */ 232 if (SANITIZER_X32) 233 val = 1728; // Assume only one particular version for x32. 234 // For ARM sizeof(struct pthread) changed in Glibc 2.23. 235 else if (SANITIZER_ARM) 236 val = minor <= 22 ? 1120 : 1216; 237 else if (minor <= 3) 238 val = FIRST_32_SECOND_64(1104, 1696); 239 else if (minor == 4) 240 val = FIRST_32_SECOND_64(1120, 1728); 241 else if (minor == 5) 242 val = FIRST_32_SECOND_64(1136, 1728); 243 else if (minor <= 9) 244 val = FIRST_32_SECOND_64(1136, 1712); 245 else if (minor == 10) 246 val = FIRST_32_SECOND_64(1168, 1776); 247 else if (minor == 11 || (minor == 12 && patch == 1)) 248 val = FIRST_32_SECOND_64(1168, 2288); 249 else if (minor <= 14) 250 val = FIRST_32_SECOND_64(1168, 2304); 251 else if (minor < 32) // Unknown version 252 val = FIRST_32_SECOND_64(1216, 2304); 253 else // minor == 32 254 val = FIRST_32_SECOND_64(1344, 2496); 255 } 256 #elif defined(__s390__) || defined(__sparc__) 257 // The size of a prefix of TCB including pthread::{specific_1stblock,specific} 258 // suffices. Just return offsetof(struct pthread, specific_used), which hasn't 259 // changed since 2007-05. Technically this applies to i386/x86_64 as well but 260 // we call _dl_get_tls_static_info and need the precise size of struct 261 // pthread. 262 return FIRST_32_SECOND_64(524, 1552); 263 #elif defined(__mips__) 264 // TODO(sagarthakur): add more values as per different glibc versions. 265 val = FIRST_32_SECOND_64(1152, 1776); 266 #elif SANITIZER_RISCV64 267 int major; 268 int minor; 269 int patch; 270 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 271 // TODO: consider adding an optional runtime check for an unknown (untested) 272 // glibc version 273 if (minor <= 28) // WARNING: the highest tested version is 2.29 274 val = 1772; // no guarantees for this one 275 else if (minor <= 31) 276 val = 1772; // tested against glibc 2.29, 2.31 277 else 278 val = 1936; // tested against glibc 2.32 279 } 280 281 #elif defined(__aarch64__) 282 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22. 283 val = 1776; 284 #elif defined(__powerpc64__) 285 val = 1776; // from glibc.ppc64le 2.20-8.fc21 286 #endif 287 return val; 288 } 289 290 uptr ThreadDescriptorSize() { 291 uptr val = atomic_load_relaxed(&thread_descriptor_size); 292 if (val) 293 return val; 294 // _thread_db_sizeof_pthread is a GLIBC_PRIVATE symbol that is exported in 295 // glibc 2.34 and later. 296 if (unsigned *psizeof = static_cast<unsigned *>( 297 dlsym(RTLD_DEFAULT, "_thread_db_sizeof_pthread"))) 298 val = *psizeof; 299 if (!val) 300 val = ThreadDescriptorSizeFallback(); 301 atomic_store_relaxed(&thread_descriptor_size, val); 302 return val; 303 } 304 305 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 306 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb 307 // head structure. It lies before the static tls blocks. 308 static uptr TlsPreTcbSize() { 309 #if defined(__mips__) 310 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 311 #elif defined(__powerpc64__) 312 const uptr kTcbHead = 88; // sizeof (tcbhead_t) 313 #elif SANITIZER_RISCV64 314 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 315 #endif 316 const uptr kTlsAlign = 16; 317 const uptr kTlsPreTcbSize = 318 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign); 319 return kTlsPreTcbSize; 320 } 321 #endif 322 323 namespace { 324 struct TlsBlock { 325 uptr begin, end, align; 326 size_t tls_modid; 327 bool operator<(const TlsBlock &rhs) const { return begin < rhs.begin; } 328 }; 329 } // namespace 330 331 #ifdef __s390__ 332 extern "C" uptr __tls_get_offset(void *arg); 333 334 static uptr TlsGetOffset(uptr ti_module, uptr ti_offset) { 335 // The __tls_get_offset ABI requires %r12 to point to GOT and %r2 to be an 336 // offset of a struct tls_index inside GOT. We don't possess either of the 337 // two, so violate the letter of the "ELF Handling For Thread-Local 338 // Storage" document and assume that the implementation just dereferences 339 // %r2 + %r12. 340 uptr tls_index[2] = {ti_module, ti_offset}; 341 register uptr r2 asm("2") = 0; 342 register void *r12 asm("12") = tls_index; 343 asm("basr %%r14, %[__tls_get_offset]" 344 : "+r"(r2) 345 : [__tls_get_offset] "r"(__tls_get_offset), "r"(r12) 346 : "memory", "cc", "0", "1", "3", "4", "5", "14"); 347 return r2; 348 } 349 #else 350 extern "C" void *__tls_get_addr(size_t *); 351 #endif 352 353 static int CollectStaticTlsBlocks(struct dl_phdr_info *info, size_t size, 354 void *data) { 355 if (!info->dlpi_tls_modid) 356 return 0; 357 uptr begin = (uptr)info->dlpi_tls_data; 358 if (!g_use_dlpi_tls_data) { 359 // Call __tls_get_addr as a fallback. This forces TLS allocation on glibc 360 // and FreeBSD. 361 #ifdef __s390__ 362 begin = (uptr)__builtin_thread_pointer() + 363 TlsGetOffset(info->dlpi_tls_modid, 0); 364 #else 365 size_t mod_and_off[2] = {info->dlpi_tls_modid, 0}; 366 begin = (uptr)__tls_get_addr(mod_and_off); 367 #endif 368 } 369 for (unsigned i = 0; i != info->dlpi_phnum; ++i) 370 if (info->dlpi_phdr[i].p_type == PT_TLS) { 371 static_cast<InternalMmapVector<TlsBlock> *>(data)->push_back( 372 TlsBlock{begin, begin + info->dlpi_phdr[i].p_memsz, 373 info->dlpi_phdr[i].p_align, info->dlpi_tls_modid}); 374 break; 375 } 376 return 0; 377 } 378 379 __attribute__((unused)) static void GetStaticTlsBoundary(uptr *addr, uptr *size, 380 uptr *align) { 381 InternalMmapVector<TlsBlock> ranges; 382 dl_iterate_phdr(CollectStaticTlsBlocks, &ranges); 383 uptr len = ranges.size(); 384 Sort(ranges.begin(), len); 385 // Find the range with tls_modid=1. For glibc, because libc.so uses PT_TLS, 386 // this module is guaranteed to exist and is one of the initially loaded 387 // modules. 388 uptr one = 0; 389 while (one != len && ranges[one].tls_modid != 1) ++one; 390 if (one == len) { 391 // This may happen with musl if no module uses PT_TLS. 392 *addr = 0; 393 *size = 0; 394 *align = 1; 395 return; 396 } 397 // Find the maximum consecutive ranges. We consider two modules consecutive if 398 // the gap is smaller than the alignment of the latter range. The dynamic 399 // loader places static TLS blocks this way not to waste space. 400 uptr l = one; 401 *align = ranges[l].align; 402 while (l != 0 && ranges[l].begin < ranges[l - 1].end + ranges[l].align) 403 *align = Max(*align, ranges[--l].align); 404 uptr r = one + 1; 405 while (r != len && ranges[r].begin < ranges[r - 1].end + ranges[r].align) 406 *align = Max(*align, ranges[r++].align); 407 *addr = ranges[l].begin; 408 *size = ranges[r - 1].end - ranges[l].begin; 409 } 410 #endif // (x86_64 || i386 || mips || ...) && (SANITIZER_FREEBSD || 411 // SANITIZER_LINUX) && !SANITIZER_ANDROID && !SANITIZER_GO 412 413 #if SANITIZER_NETBSD 414 static struct tls_tcb * ThreadSelfTlsTcb() { 415 struct tls_tcb *tcb = nullptr; 416 #ifdef __HAVE___LWP_GETTCB_FAST 417 tcb = (struct tls_tcb *)__lwp_gettcb_fast(); 418 #elif defined(__HAVE___LWP_GETPRIVATE_FAST) 419 tcb = (struct tls_tcb *)__lwp_getprivate_fast(); 420 #endif 421 return tcb; 422 } 423 424 uptr ThreadSelf() { 425 return (uptr)ThreadSelfTlsTcb()->tcb_pthread; 426 } 427 428 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) { 429 const Elf_Phdr *hdr = info->dlpi_phdr; 430 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum; 431 432 for (; hdr != last_hdr; ++hdr) { 433 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) { 434 *(uptr*)data = hdr->p_memsz; 435 break; 436 } 437 } 438 return 0; 439 } 440 #endif // SANITIZER_NETBSD 441 442 #if SANITIZER_ANDROID 443 // Bionic provides this API since S. 444 extern "C" SANITIZER_WEAK_ATTRIBUTE void __libc_get_static_tls_bounds(void **, 445 void **); 446 #endif 447 448 #if !SANITIZER_GO 449 static void GetTls(uptr *addr, uptr *size) { 450 #if SANITIZER_ANDROID 451 if (&__libc_get_static_tls_bounds) { 452 void *start_addr; 453 void *end_addr; 454 __libc_get_static_tls_bounds(&start_addr, &end_addr); 455 *addr = reinterpret_cast<uptr>(start_addr); 456 *size = 457 reinterpret_cast<uptr>(end_addr) - reinterpret_cast<uptr>(start_addr); 458 } else { 459 *addr = 0; 460 *size = 0; 461 } 462 #elif SANITIZER_GLIBC && defined(__x86_64__) 463 // For aarch64 and x86-64, use an O(1) approach which requires relatively 464 // precise ThreadDescriptorSize. g_tls_size was initialized in InitTlsSize. 465 # if SANITIZER_X32 466 asm("mov %%fs:8,%0" : "=r"(*addr)); 467 # else 468 asm("mov %%fs:16,%0" : "=r"(*addr)); 469 # endif 470 *size = g_tls_size; 471 *addr -= *size; 472 *addr += ThreadDescriptorSize(); 473 #elif SANITIZER_GLIBC && defined(__aarch64__) 474 *addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) - 475 ThreadDescriptorSize(); 476 *size = g_tls_size + ThreadDescriptorSize(); 477 #elif SANITIZER_GLIBC && defined(__powerpc64__) 478 // Workaround for glibc<2.25(?). 2.27 is known to not need this. 479 uptr tp; 480 asm("addi %0,13,-0x7000" : "=r"(tp)); 481 const uptr pre_tcb_size = TlsPreTcbSize(); 482 *addr = tp - pre_tcb_size; 483 *size = g_tls_size + pre_tcb_size; 484 #elif SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_SOLARIS 485 uptr align; 486 GetStaticTlsBoundary(addr, size, &align); 487 #if defined(__x86_64__) || defined(__i386__) || defined(__s390__) || \ 488 defined(__sparc__) 489 if (SANITIZER_GLIBC) { 490 #if defined(__x86_64__) || defined(__i386__) 491 align = Max<uptr>(align, 64); 492 #else 493 align = Max<uptr>(align, 16); 494 #endif 495 } 496 const uptr tp = RoundUpTo(*addr + *size, align); 497 498 // lsan requires the range to additionally cover the static TLS surplus 499 // (elf/dl-tls.c defines 1664). Otherwise there may be false positives for 500 // allocations only referenced by tls in dynamically loaded modules. 501 if (SANITIZER_GLIBC) 502 *size += 1644; 503 else if (SANITIZER_FREEBSD) 504 *size += 128; // RTLD_STATIC_TLS_EXTRA 505 506 // Extend the range to include the thread control block. On glibc, lsan needs 507 // the range to include pthread::{specific_1stblock,specific} so that 508 // allocations only referenced by pthread_setspecific can be scanned. This may 509 // underestimate by at most TLS_TCB_ALIGN-1 bytes but it should be fine 510 // because the number of bytes after pthread::specific is larger. 511 *addr = tp - RoundUpTo(*size, align); 512 *size = tp - *addr + ThreadDescriptorSize(); 513 #else 514 if (SANITIZER_GLIBC) 515 *size += 1664; 516 else if (SANITIZER_FREEBSD) 517 *size += 128; // RTLD_STATIC_TLS_EXTRA 518 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 519 const uptr pre_tcb_size = TlsPreTcbSize(); 520 *addr -= pre_tcb_size; 521 *size += pre_tcb_size; 522 #else 523 // arm and aarch64 reserve two words at TP, so this underestimates the range. 524 // However, this is sufficient for the purpose of finding the pointers to 525 // thread-specific data keys. 526 const uptr tcb_size = ThreadDescriptorSize(); 527 *addr -= tcb_size; 528 *size += tcb_size; 529 #endif 530 #endif 531 #elif SANITIZER_NETBSD 532 struct tls_tcb * const tcb = ThreadSelfTlsTcb(); 533 *addr = 0; 534 *size = 0; 535 if (tcb != 0) { 536 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program). 537 // ld.elf_so hardcodes the index 1. 538 dl_iterate_phdr(GetSizeFromHdr, size); 539 540 if (*size != 0) { 541 // The block has been found and tcb_dtv[1] contains the base address 542 *addr = (uptr)tcb->tcb_dtv[1]; 543 } 544 } 545 #error "Unknown OS" 546 #endif 547 } 548 #endif 549 550 #if !SANITIZER_GO 551 uptr GetTlsSize() { 552 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \ 553 SANITIZER_SOLARIS 554 uptr addr, size; 555 GetTls(&addr, &size); 556 return size; 557 #else 558 return 0; 559 #endif 560 } 561 #endif 562 563 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, 564 uptr *tls_addr, uptr *tls_size) { 565 #if SANITIZER_GO 566 // Stub implementation for Go. 567 *stk_addr = *stk_size = *tls_addr = *tls_size = 0; 568 #else 569 GetTls(tls_addr, tls_size); 570 571 uptr stack_top, stack_bottom; 572 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); 573 *stk_addr = stack_bottom; 574 *stk_size = stack_top - stack_bottom; 575 576 if (!main) { 577 // If stack and tls intersect, make them non-intersecting. 578 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { 579 if (*stk_addr + *stk_size < *tls_addr + *tls_size) 580 *tls_size = *stk_addr + *stk_size - *tls_addr; 581 *stk_size = *tls_addr - *stk_addr; 582 } 583 } 584 #endif 585 } 586 587 #if !SANITIZER_FREEBSD 588 typedef ElfW(Phdr) Elf_Phdr; 589 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2 590 #define Elf_Phdr XElf32_Phdr 591 #define dl_phdr_info xdl_phdr_info 592 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b)) 593 #endif // !SANITIZER_FREEBSD 594 595 struct DlIteratePhdrData { 596 InternalMmapVectorNoCtor<LoadedModule> *modules; 597 bool first; 598 }; 599 600 static int AddModuleSegments(const char *module_name, dl_phdr_info *info, 601 InternalMmapVectorNoCtor<LoadedModule> *modules) { 602 if (module_name[0] == '\0') 603 return 0; 604 LoadedModule cur_module; 605 cur_module.set(module_name, info->dlpi_addr); 606 for (int i = 0; i < (int)info->dlpi_phnum; i++) { 607 const Elf_Phdr *phdr = &info->dlpi_phdr[i]; 608 if (phdr->p_type == PT_LOAD) { 609 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr; 610 uptr cur_end = cur_beg + phdr->p_memsz; 611 bool executable = phdr->p_flags & PF_X; 612 bool writable = phdr->p_flags & PF_W; 613 cur_module.addAddressRange(cur_beg, cur_end, executable, 614 writable); 615 } else if (phdr->p_type == PT_NOTE) { 616 # ifdef NT_GNU_BUILD_ID 617 uptr off = 0; 618 while (off + sizeof(ElfW(Nhdr)) < phdr->p_memsz) { 619 auto *nhdr = reinterpret_cast<const ElfW(Nhdr) *>(info->dlpi_addr + 620 phdr->p_vaddr + off); 621 constexpr auto kGnuNamesz = 4; // "GNU" with NUL-byte. 622 static_assert(kGnuNamesz % 4 == 0, "kGnuNameSize is aligned to 4."); 623 if (nhdr->n_type == NT_GNU_BUILD_ID && nhdr->n_namesz == kGnuNamesz) { 624 if (off + sizeof(ElfW(Nhdr)) + nhdr->n_namesz + nhdr->n_descsz > 625 phdr->p_memsz) { 626 // Something is very wrong, bail out instead of reading potentially 627 // arbitrary memory. 628 break; 629 } 630 const char *name = 631 reinterpret_cast<const char *>(nhdr) + sizeof(*nhdr); 632 if (internal_memcmp(name, "GNU", 3) == 0) { 633 const char *value = reinterpret_cast<const char *>(nhdr) + 634 sizeof(*nhdr) + kGnuNamesz; 635 cur_module.setUuid(value, nhdr->n_descsz); 636 break; 637 } 638 } 639 off += sizeof(*nhdr) + RoundUpTo(nhdr->n_namesz, 4) + 640 RoundUpTo(nhdr->n_descsz, 4); 641 } 642 # endif 643 } 644 } 645 modules->push_back(cur_module); 646 return 0; 647 } 648 649 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) { 650 DlIteratePhdrData *data = (DlIteratePhdrData *)arg; 651 if (data->first) { 652 InternalMmapVector<char> module_name(kMaxPathLength); 653 data->first = false; 654 // First module is the binary itself. 655 ReadBinaryNameCached(module_name.data(), module_name.size()); 656 return AddModuleSegments(module_name.data(), info, data->modules); 657 } 658 659 if (info->dlpi_name) { 660 InternalScopedString module_name; 661 module_name.append("%s", info->dlpi_name); 662 return AddModuleSegments(module_name.data(), info, data->modules); 663 } 664 665 return 0; 666 } 667 668 #if SANITIZER_ANDROID && __ANDROID_API__ < 21 669 extern "C" __attribute__((weak)) int dl_iterate_phdr( 670 int (*)(struct dl_phdr_info *, size_t, void *), void *); 671 #endif 672 673 static bool requiresProcmaps() { 674 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22 675 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken. 676 // The runtime check allows the same library to work with 677 // both K and L (and future) Android releases. 678 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1; 679 #else 680 return false; 681 #endif 682 } 683 684 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) { 685 MemoryMappingLayout memory_mapping(/*cache_enabled*/true); 686 memory_mapping.DumpListOfModules(modules); 687 } 688 689 void ListOfModules::init() { 690 clearOrInit(); 691 if (requiresProcmaps()) { 692 procmapsInit(&modules_); 693 } else { 694 DlIteratePhdrData data = {&modules_, true}; 695 dl_iterate_phdr(dl_iterate_phdr_cb, &data); 696 } 697 } 698 699 // When a custom loader is used, dl_iterate_phdr may not contain the full 700 // list of modules. Allow callers to fall back to using procmaps. 701 void ListOfModules::fallbackInit() { 702 if (!requiresProcmaps()) { 703 clearOrInit(); 704 procmapsInit(&modules_); 705 } else { 706 clear(); 707 } 708 } 709 710 // getrusage does not give us the current RSS, only the max RSS. 711 // Still, this is better than nothing if /proc/self/statm is not available 712 // for some reason, e.g. due to a sandbox. 713 static uptr GetRSSFromGetrusage() { 714 struct rusage usage; 715 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox. 716 return 0; 717 return usage.ru_maxrss << 10; // ru_maxrss is in Kb. 718 } 719 720 uptr GetRSS() { 721 if (!common_flags()->can_use_proc_maps_statm) 722 return GetRSSFromGetrusage(); 723 fd_t fd = OpenFile("/proc/self/statm", RdOnly); 724 if (fd == kInvalidFd) 725 return GetRSSFromGetrusage(); 726 char buf[64]; 727 uptr len = internal_read(fd, buf, sizeof(buf) - 1); 728 internal_close(fd); 729 if ((sptr)len <= 0) 730 return 0; 731 buf[len] = 0; 732 // The format of the file is: 733 // 1084 89 69 11 0 79 0 734 // We need the second number which is RSS in pages. 735 char *pos = buf; 736 // Skip the first number. 737 while (*pos >= '0' && *pos <= '9') 738 pos++; 739 // Skip whitespaces. 740 while (!(*pos >= '0' && *pos <= '9') && *pos != 0) 741 pos++; 742 // Read the number. 743 uptr rss = 0; 744 while (*pos >= '0' && *pos <= '9') 745 rss = rss * 10 + *pos++ - '0'; 746 return rss * GetPageSizeCached(); 747 } 748 749 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as 750 // they allocate memory. 751 u32 GetNumberOfCPUs() { 752 #if SANITIZER_FREEBSD || SANITIZER_NETBSD 753 u32 ncpu; 754 int req[2]; 755 uptr len = sizeof(ncpu); 756 req[0] = CTL_HW; 757 req[1] = HW_NCPU; 758 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0); 759 return ncpu; 760 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__) 761 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't 762 // exist in sched.h. That is the case for toolchains generated with older 763 // NDKs. 764 // This code doesn't work on AArch64 because internal_getdents makes use of 765 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64. 766 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY); 767 if (internal_iserror(fd)) 768 return 0; 769 InternalMmapVector<u8> buffer(4096); 770 uptr bytes_read = buffer.size(); 771 uptr n_cpus = 0; 772 u8 *d_type; 773 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read]; 774 while (true) { 775 if ((u8 *)entry >= &buffer[bytes_read]) { 776 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(), 777 buffer.size()); 778 if (internal_iserror(bytes_read) || !bytes_read) 779 break; 780 entry = (struct linux_dirent *)buffer.data(); 781 } 782 d_type = (u8 *)entry + entry->d_reclen - 1; 783 if (d_type >= &buffer[bytes_read] || 784 (u8 *)&entry->d_name[3] >= &buffer[bytes_read]) 785 break; 786 if (entry->d_ino != 0 && *d_type == DT_DIR) { 787 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' && 788 entry->d_name[2] == 'u' && 789 entry->d_name[3] >= '0' && entry->d_name[3] <= '9') 790 n_cpus++; 791 } 792 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen); 793 } 794 internal_close(fd); 795 return n_cpus; 796 #elif SANITIZER_SOLARIS 797 return sysconf(_SC_NPROCESSORS_ONLN); 798 #else 799 cpu_set_t CPUs; 800 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0); 801 return CPU_COUNT(&CPUs); 802 #endif 803 } 804 805 #if SANITIZER_LINUX 806 807 #if SANITIZER_ANDROID 808 static atomic_uint8_t android_log_initialized; 809 810 void AndroidLogInit() { 811 openlog(GetProcessName(), 0, LOG_USER); 812 atomic_store(&android_log_initialized, 1, memory_order_release); 813 } 814 815 static bool ShouldLogAfterPrintf() { 816 return atomic_load(&android_log_initialized, memory_order_acquire); 817 } 818 819 extern "C" SANITIZER_WEAK_ATTRIBUTE 820 int async_safe_write_log(int pri, const char* tag, const char* msg); 821 extern "C" SANITIZER_WEAK_ATTRIBUTE 822 int __android_log_write(int prio, const char* tag, const char* msg); 823 824 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime. 825 #define SANITIZER_ANDROID_LOG_INFO 4 826 827 // async_safe_write_log is a new public version of __libc_write_log that is 828 // used behind syslog. It is preferable to syslog as it will not do any dynamic 829 // memory allocation or formatting. 830 // If the function is not available, syslog is preferred for L+ (it was broken 831 // pre-L) as __android_log_write triggers a racey behavior with the strncpy 832 // interceptor. Fallback to __android_log_write pre-L. 833 void WriteOneLineToSyslog(const char *s) { 834 if (&async_safe_write_log) { 835 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s); 836 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) { 837 syslog(LOG_INFO, "%s", s); 838 } else { 839 CHECK(&__android_log_write); 840 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s); 841 } 842 } 843 844 extern "C" SANITIZER_WEAK_ATTRIBUTE 845 void android_set_abort_message(const char *); 846 847 void SetAbortMessage(const char *str) { 848 if (&android_set_abort_message) 849 android_set_abort_message(str); 850 } 851 #else 852 void AndroidLogInit() {} 853 854 static bool ShouldLogAfterPrintf() { return true; } 855 856 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); } 857 858 void SetAbortMessage(const char *str) {} 859 #endif // SANITIZER_ANDROID 860 861 void LogMessageOnPrintf(const char *str) { 862 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf()) 863 WriteToSyslog(str); 864 } 865 866 #endif // SANITIZER_LINUX 867 868 #if SANITIZER_GLIBC && !SANITIZER_GO 869 // glibc crashes when using clock_gettime from a preinit_array function as the 870 // vDSO function pointers haven't been initialized yet. __progname is 871 // initialized after the vDSO function pointers, so if it exists, is not null 872 // and is not empty, we can use clock_gettime. 873 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname; 874 inline bool CanUseVDSO() { return &__progname && __progname && *__progname; } 875 876 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling 877 // clock_gettime. real_clock_gettime only exists if clock_gettime is 878 // intercepted, so define it weakly and use it if available. 879 extern "C" SANITIZER_WEAK_ATTRIBUTE 880 int real_clock_gettime(u32 clk_id, void *tp); 881 u64 MonotonicNanoTime() { 882 timespec ts; 883 if (CanUseVDSO()) { 884 if (&real_clock_gettime) 885 real_clock_gettime(CLOCK_MONOTONIC, &ts); 886 else 887 clock_gettime(CLOCK_MONOTONIC, &ts); 888 } else { 889 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 890 } 891 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 892 } 893 #else 894 // Non-glibc & Go always use the regular function. 895 u64 MonotonicNanoTime() { 896 timespec ts; 897 clock_gettime(CLOCK_MONOTONIC, &ts); 898 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 899 } 900 #endif // SANITIZER_GLIBC && !SANITIZER_GO 901 902 void ReExec() { 903 const char *pathname = "/proc/self/exe"; 904 905 #if SANITIZER_NETBSD 906 static const int name[] = { 907 CTL_KERN, 908 KERN_PROC_ARGS, 909 -1, 910 KERN_PROC_PATHNAME, 911 }; 912 char path[400]; 913 uptr len; 914 915 len = sizeof(path); 916 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1) 917 pathname = path; 918 #elif SANITIZER_SOLARIS 919 pathname = getexecname(); 920 CHECK_NE(pathname, NULL); 921 #elif SANITIZER_USE_GETAUXVAL 922 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that 923 // rely on that will fail to load shared libraries. Query AT_EXECFN instead. 924 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN)); 925 #endif 926 927 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron()); 928 int rverrno; 929 CHECK_EQ(internal_iserror(rv, &rverrno), true); 930 Printf("execve failed, errno %d\n", rverrno); 931 Die(); 932 } 933 934 void UnmapFromTo(uptr from, uptr to) { 935 if (to == from) 936 return; 937 CHECK(to >= from); 938 uptr res = internal_munmap(reinterpret_cast<void *>(from), to - from); 939 if (UNLIKELY(internal_iserror(res))) { 940 Report("ERROR: %s failed to unmap 0x%zx (%zd) bytes at address %p\n", 941 SanitizerToolName, to - from, to - from, (void *)from); 942 CHECK("unable to unmap" && 0); 943 } 944 } 945 946 uptr MapDynamicShadow(uptr shadow_size_bytes, uptr shadow_scale, 947 uptr min_shadow_base_alignment, 948 UNUSED uptr &high_mem_end) { 949 const uptr granularity = GetMmapGranularity(); 950 const uptr alignment = 951 Max<uptr>(granularity << shadow_scale, 1ULL << min_shadow_base_alignment); 952 const uptr left_padding = 953 Max<uptr>(granularity, 1ULL << min_shadow_base_alignment); 954 955 const uptr shadow_size = RoundUpTo(shadow_size_bytes, granularity); 956 const uptr map_size = shadow_size + left_padding + alignment; 957 958 const uptr map_start = (uptr)MmapNoAccess(map_size); 959 CHECK_NE(map_start, ~(uptr)0); 960 961 const uptr shadow_start = RoundUpTo(map_start + left_padding, alignment); 962 963 UnmapFromTo(map_start, shadow_start - left_padding); 964 UnmapFromTo(shadow_start + shadow_size, map_start + map_size); 965 966 return shadow_start; 967 } 968 969 static uptr MmapSharedNoReserve(uptr addr, uptr size) { 970 return internal_mmap( 971 reinterpret_cast<void *>(addr), size, PROT_READ | PROT_WRITE, 972 MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0); 973 } 974 975 static uptr MremapCreateAlias(uptr base_addr, uptr alias_addr, 976 uptr alias_size) { 977 #if SANITIZER_LINUX 978 return internal_mremap(reinterpret_cast<void *>(base_addr), 0, alias_size, 979 MREMAP_MAYMOVE | MREMAP_FIXED, 980 reinterpret_cast<void *>(alias_addr)); 981 #else 982 CHECK(false && "mremap is not supported outside of Linux"); 983 return 0; 984 #endif 985 } 986 987 static void CreateAliases(uptr start_addr, uptr alias_size, uptr num_aliases) { 988 uptr total_size = alias_size * num_aliases; 989 uptr mapped = MmapSharedNoReserve(start_addr, total_size); 990 CHECK_EQ(mapped, start_addr); 991 992 for (uptr i = 1; i < num_aliases; ++i) { 993 uptr alias_addr = start_addr + i * alias_size; 994 CHECK_EQ(MremapCreateAlias(start_addr, alias_addr, alias_size), alias_addr); 995 } 996 } 997 998 uptr MapDynamicShadowAndAliases(uptr shadow_size, uptr alias_size, 999 uptr num_aliases, uptr ring_buffer_size) { 1000 CHECK_EQ(alias_size & (alias_size - 1), 0); 1001 CHECK_EQ(num_aliases & (num_aliases - 1), 0); 1002 CHECK_EQ(ring_buffer_size & (ring_buffer_size - 1), 0); 1003 1004 const uptr granularity = GetMmapGranularity(); 1005 shadow_size = RoundUpTo(shadow_size, granularity); 1006 CHECK_EQ(shadow_size & (shadow_size - 1), 0); 1007 1008 const uptr alias_region_size = alias_size * num_aliases; 1009 const uptr alignment = 1010 2 * Max(Max(shadow_size, alias_region_size), ring_buffer_size); 1011 const uptr left_padding = ring_buffer_size; 1012 1013 const uptr right_size = alignment; 1014 const uptr map_size = left_padding + 2 * alignment; 1015 1016 const uptr map_start = reinterpret_cast<uptr>(MmapNoAccess(map_size)); 1017 CHECK_NE(map_start, static_cast<uptr>(-1)); 1018 const uptr right_start = RoundUpTo(map_start + left_padding, alignment); 1019 1020 UnmapFromTo(map_start, right_start - left_padding); 1021 UnmapFromTo(right_start + right_size, map_start + map_size); 1022 1023 CreateAliases(right_start + right_size / 2, alias_size, num_aliases); 1024 1025 return right_start; 1026 } 1027 1028 void InitializePlatformCommonFlags(CommonFlags *cf) { 1029 #if SANITIZER_ANDROID 1030 if (&__libc_get_static_tls_bounds == nullptr) 1031 cf->detect_leaks = false; 1032 #endif 1033 } 1034 1035 } // namespace __sanitizer 1036 1037 #endif 1038