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 <stdlib.h> 50 #include <osreldate.h> 51 #include <sys/auxv.h> 52 #include <sys/sysctl.h> 53 #define pthread_getattr_np pthread_attr_get_np 54 // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before 55 // that, it was never implemented. So just define it to zero. 56 #undef MAP_NORESERVE 57 #define MAP_NORESERVE 0 58 #endif 59 60 #if SANITIZER_NETBSD 61 #include <sys/sysctl.h> 62 #include <sys/tls.h> 63 #include <lwp.h> 64 #endif 65 66 #if SANITIZER_SOLARIS 67 #include <stdlib.h> 68 #include <thread.h> 69 #endif 70 71 #if SANITIZER_ANDROID 72 #include <android/api-level.h> 73 #if !defined(CPU_COUNT) && !defined(__aarch64__) 74 #include <dirent.h> 75 #include <fcntl.h> 76 struct __sanitizer::linux_dirent { 77 long d_ino; 78 off_t d_off; 79 unsigned short d_reclen; 80 char d_name[]; 81 }; 82 #endif 83 #endif 84 85 #if !SANITIZER_ANDROID 86 #include <elf.h> 87 #include <unistd.h> 88 #endif 89 90 namespace __sanitizer { 91 92 SANITIZER_WEAK_ATTRIBUTE int 93 real_sigaction(int signum, const void *act, void *oldact); 94 95 int internal_sigaction(int signum, const void *act, void *oldact) { 96 #if !SANITIZER_GO 97 if (&real_sigaction) 98 return real_sigaction(signum, act, oldact); 99 #endif 100 return sigaction(signum, (const struct sigaction *)act, 101 (struct sigaction *)oldact); 102 } 103 104 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top, 105 uptr *stack_bottom) { 106 CHECK(stack_top); 107 CHECK(stack_bottom); 108 if (at_initialization) { 109 // This is the main thread. Libpthread may not be initialized yet. 110 struct rlimit rl; 111 CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0); 112 113 // Find the mapping that contains a stack variable. 114 MemoryMappingLayout proc_maps(/*cache_enabled*/true); 115 if (proc_maps.Error()) { 116 *stack_top = *stack_bottom = 0; 117 return; 118 } 119 MemoryMappedSegment segment; 120 uptr prev_end = 0; 121 while (proc_maps.Next(&segment)) { 122 if ((uptr)&rl < segment.end) break; 123 prev_end = segment.end; 124 } 125 CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end); 126 127 // Get stacksize from rlimit, but clip it so that it does not overlap 128 // with other mappings. 129 uptr stacksize = rl.rlim_cur; 130 if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end; 131 // When running with unlimited stack size, we still want to set some limit. 132 // The unlimited stack size is caused by 'ulimit -s unlimited'. 133 // Also, for some reason, GNU make spawns subprocesses with unlimited stack. 134 if (stacksize > kMaxThreadStackSize) 135 stacksize = kMaxThreadStackSize; 136 *stack_top = segment.end; 137 *stack_bottom = segment.end - stacksize; 138 return; 139 } 140 uptr stacksize = 0; 141 void *stackaddr = nullptr; 142 #if SANITIZER_SOLARIS 143 stack_t ss; 144 CHECK_EQ(thr_stksegment(&ss), 0); 145 stacksize = ss.ss_size; 146 stackaddr = (char *)ss.ss_sp - stacksize; 147 #else // !SANITIZER_SOLARIS 148 pthread_attr_t attr; 149 pthread_attr_init(&attr); 150 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0); 151 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize); 152 pthread_attr_destroy(&attr); 153 #endif // SANITIZER_SOLARIS 154 155 *stack_top = (uptr)stackaddr + stacksize; 156 *stack_bottom = (uptr)stackaddr; 157 } 158 159 #if !SANITIZER_GO 160 bool SetEnv(const char *name, const char *value) { 161 void *f = dlsym(RTLD_NEXT, "setenv"); 162 if (!f) 163 return false; 164 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite); 165 setenv_ft setenv_f; 166 CHECK_EQ(sizeof(setenv_f), sizeof(f)); 167 internal_memcpy(&setenv_f, &f, sizeof(f)); 168 return setenv_f(name, value, 1) == 0; 169 } 170 #endif 171 172 __attribute__((unused)) static bool GetLibcVersion(int *major, int *minor, 173 int *patch) { 174 #ifdef _CS_GNU_LIBC_VERSION 175 char buf[64]; 176 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf)); 177 if (len >= sizeof(buf)) 178 return false; 179 buf[len] = 0; 180 static const char kGLibC[] = "glibc "; 181 if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0) 182 return false; 183 const char *p = buf + sizeof(kGLibC) - 1; 184 *major = internal_simple_strtoll(p, &p, 10); 185 *minor = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 186 *patch = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 187 return true; 188 #else 189 return false; 190 #endif 191 } 192 193 // True if we can use dlpi_tls_data. glibc before 2.25 may leave NULL (BZ 194 // #19826) so dlpi_tls_data cannot be used. 195 // 196 // musl before 1.2.3 and FreeBSD as of 12.2 incorrectly set dlpi_tls_data to 197 // the TLS initialization image 198 // https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=254774 199 __attribute__((unused)) static int g_use_dlpi_tls_data; 200 201 #if SANITIZER_GLIBC && !SANITIZER_GO 202 __attribute__((unused)) static size_t g_tls_size; 203 void InitTlsSize() { 204 int major, minor, patch; 205 g_use_dlpi_tls_data = 206 GetLibcVersion(&major, &minor, &patch) && major == 2 && minor >= 25; 207 208 #if defined(__aarch64__) || defined(__x86_64__) || defined(__powerpc64__) 209 void *get_tls_static_info = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); 210 size_t tls_align; 211 ((void (*)(size_t *, size_t *))get_tls_static_info)(&g_tls_size, &tls_align); 212 #endif 213 } 214 #else 215 void InitTlsSize() { } 216 #endif // SANITIZER_GLIBC && !SANITIZER_GO 217 218 // On glibc x86_64, ThreadDescriptorSize() needs to be precise due to the usage 219 // of g_tls_size. On other targets, ThreadDescriptorSize() is only used by lsan 220 // to get the pointer to thread-specific data keys in the thread control block. 221 #if (SANITIZER_FREEBSD || SANITIZER_LINUX) && !SANITIZER_ANDROID 222 // sizeof(struct pthread) from glibc. 223 static atomic_uintptr_t thread_descriptor_size; 224 225 uptr ThreadDescriptorSize() { 226 uptr val = atomic_load_relaxed(&thread_descriptor_size); 227 if (val) 228 return val; 229 #if defined(__x86_64__) || defined(__i386__) || defined(__arm__) 230 int major; 231 int minor; 232 int patch; 233 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 234 /* sizeof(struct pthread) values from various glibc versions. */ 235 if (SANITIZER_X32) 236 val = 1728; // Assume only one particular version for x32. 237 // For ARM sizeof(struct pthread) changed in Glibc 2.23. 238 else if (SANITIZER_ARM) 239 val = minor <= 22 ? 1120 : 1216; 240 else if (minor <= 3) 241 val = FIRST_32_SECOND_64(1104, 1696); 242 else if (minor == 4) 243 val = FIRST_32_SECOND_64(1120, 1728); 244 else if (minor == 5) 245 val = FIRST_32_SECOND_64(1136, 1728); 246 else if (minor <= 9) 247 val = FIRST_32_SECOND_64(1136, 1712); 248 else if (minor == 10) 249 val = FIRST_32_SECOND_64(1168, 1776); 250 else if (minor == 11 || (minor == 12 && patch == 1)) 251 val = FIRST_32_SECOND_64(1168, 2288); 252 else if (minor <= 14) 253 val = FIRST_32_SECOND_64(1168, 2304); 254 else if (minor < 32) // Unknown version 255 val = FIRST_32_SECOND_64(1216, 2304); 256 else // minor == 32 257 val = FIRST_32_SECOND_64(1344, 2496); 258 } 259 #elif defined(__s390__) || defined(__sparc__) 260 // The size of a prefix of TCB including pthread::{specific_1stblock,specific} 261 // suffices. Just return offsetof(struct pthread, specific_used), which hasn't 262 // changed since 2007-05. Technically this applies to i386/x86_64 as well but 263 // we call _dl_get_tls_static_info and need the precise size of struct 264 // pthread. 265 return FIRST_32_SECOND_64(524, 1552); 266 #elif defined(__mips__) 267 // TODO(sagarthakur): add more values as per different glibc versions. 268 val = FIRST_32_SECOND_64(1152, 1776); 269 #elif SANITIZER_RISCV64 270 int major; 271 int minor; 272 int patch; 273 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 274 // TODO: consider adding an optional runtime check for an unknown (untested) 275 // glibc version 276 if (minor <= 28) // WARNING: the highest tested version is 2.29 277 val = 1772; // no guarantees for this one 278 else if (minor <= 31) 279 val = 1772; // tested against glibc 2.29, 2.31 280 else 281 val = 1936; // tested against glibc 2.32 282 } 283 284 #elif defined(__aarch64__) 285 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22. 286 val = 1776; 287 #elif defined(__powerpc64__) 288 val = 1776; // from glibc.ppc64le 2.20-8.fc21 289 #endif 290 if (val) 291 atomic_store_relaxed(&thread_descriptor_size, val); 292 return val; 293 } 294 295 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 296 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb 297 // head structure. It lies before the static tls blocks. 298 static uptr TlsPreTcbSize() { 299 #if defined(__mips__) 300 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 301 #elif defined(__powerpc64__) 302 const uptr kTcbHead = 88; // sizeof (tcbhead_t) 303 #elif SANITIZER_RISCV64 304 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 305 #endif 306 const uptr kTlsAlign = 16; 307 const uptr kTlsPreTcbSize = 308 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign); 309 return kTlsPreTcbSize; 310 } 311 #endif 312 313 #if !SANITIZER_GO 314 namespace { 315 struct TlsBlock { 316 uptr begin, end, align; 317 size_t tls_modid; 318 bool operator<(const TlsBlock &rhs) const { return begin < rhs.begin; } 319 }; 320 } // namespace 321 322 #ifdef __s390__ 323 extern "C" uptr __tls_get_offset(void *arg); 324 325 static uptr TlsGetOffset(uptr ti_module, uptr ti_offset) { 326 // The __tls_get_offset ABI requires %r12 to point to GOT and %r2 to be an 327 // offset of a struct tls_index inside GOT. We don't possess either of the 328 // two, so violate the letter of the "ELF Handling For Thread-Local 329 // Storage" document and assume that the implementation just dereferences 330 // %r2 + %r12. 331 uptr tls_index[2] = {ti_module, ti_offset}; 332 register uptr r2 asm("2") = 0; 333 register void *r12 asm("12") = tls_index; 334 asm("basr %%r14, %[__tls_get_offset]" 335 : "+r"(r2) 336 : [__tls_get_offset] "r"(__tls_get_offset), "r"(r12) 337 : "memory", "cc", "0", "1", "3", "4", "5", "14"); 338 return r2; 339 } 340 #else 341 extern "C" void *__tls_get_addr(size_t *); 342 #endif 343 344 static int CollectStaticTlsBlocks(struct dl_phdr_info *info, size_t size, 345 void *data) { 346 if (!info->dlpi_tls_modid) 347 return 0; 348 uptr begin = (uptr)info->dlpi_tls_data; 349 if (!g_use_dlpi_tls_data) { 350 // Call __tls_get_addr as a fallback. This forces TLS allocation on glibc 351 // and FreeBSD. 352 #ifdef __s390__ 353 begin = (uptr)__builtin_thread_pointer() + 354 TlsGetOffset(info->dlpi_tls_modid, 0); 355 #else 356 size_t mod_and_off[2] = {info->dlpi_tls_modid, 0}; 357 begin = (uptr)__tls_get_addr(mod_and_off); 358 #endif 359 } 360 for (unsigned i = 0; i != info->dlpi_phnum; ++i) 361 if (info->dlpi_phdr[i].p_type == PT_TLS) { 362 static_cast<InternalMmapVector<TlsBlock> *>(data)->push_back( 363 TlsBlock{begin, begin + info->dlpi_phdr[i].p_memsz, 364 info->dlpi_phdr[i].p_align, info->dlpi_tls_modid}); 365 break; 366 } 367 return 0; 368 } 369 370 __attribute__((unused)) static void GetStaticTlsBoundary(uptr *addr, uptr *size, 371 uptr *align) { 372 InternalMmapVector<TlsBlock> ranges; 373 dl_iterate_phdr(CollectStaticTlsBlocks, &ranges); 374 uptr len = ranges.size(); 375 Sort(ranges.begin(), len); 376 // Find the range with tls_modid=1. For glibc, because libc.so uses PT_TLS, 377 // this module is guaranteed to exist and is one of the initially loaded 378 // modules. 379 uptr one = 0; 380 while (one != len && ranges[one].tls_modid != 1) ++one; 381 if (one == len) { 382 // This may happen with musl if no module uses PT_TLS. 383 *addr = 0; 384 *size = 0; 385 *align = 1; 386 return; 387 } 388 // Find the maximum consecutive ranges. We consider two modules consecutive if 389 // the gap is smaller than the alignment. The dynamic loader places static TLS 390 // blocks this way not to waste space. 391 uptr l = one; 392 *align = ranges[l].align; 393 while (l != 0 && ranges[l].begin < ranges[l - 1].end + ranges[l - 1].align) 394 *align = Max(*align, ranges[--l].align); 395 uptr r = one + 1; 396 while (r != len && ranges[r].begin < ranges[r - 1].end + ranges[r - 1].align) 397 *align = Max(*align, ranges[r++].align); 398 *addr = ranges[l].begin; 399 *size = ranges[r - 1].end - ranges[l].begin; 400 } 401 #endif // !SANITIZER_GO 402 #endif // (x86_64 || i386 || mips || ...) && (SANITIZER_FREEBSD || 403 // SANITIZER_LINUX) && !SANITIZER_ANDROID 404 405 #if SANITIZER_NETBSD 406 static struct tls_tcb * ThreadSelfTlsTcb() { 407 struct tls_tcb *tcb = nullptr; 408 #ifdef __HAVE___LWP_GETTCB_FAST 409 tcb = (struct tls_tcb *)__lwp_gettcb_fast(); 410 #elif defined(__HAVE___LWP_GETPRIVATE_FAST) 411 tcb = (struct tls_tcb *)__lwp_getprivate_fast(); 412 #endif 413 return tcb; 414 } 415 416 uptr ThreadSelf() { 417 return (uptr)ThreadSelfTlsTcb()->tcb_pthread; 418 } 419 420 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) { 421 const Elf_Phdr *hdr = info->dlpi_phdr; 422 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum; 423 424 for (; hdr != last_hdr; ++hdr) { 425 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) { 426 *(uptr*)data = hdr->p_memsz; 427 break; 428 } 429 } 430 return 0; 431 } 432 #endif // SANITIZER_NETBSD 433 434 #if SANITIZER_ANDROID 435 // Bionic provides this API since S. 436 extern "C" SANITIZER_WEAK_ATTRIBUTE void __libc_get_static_tls_bounds(void **, 437 void **); 438 #endif 439 440 #if !SANITIZER_GO 441 static void GetTls(uptr *addr, uptr *size) { 442 #if SANITIZER_ANDROID 443 if (&__libc_get_static_tls_bounds) { 444 void *start_addr; 445 void *end_addr; 446 __libc_get_static_tls_bounds(&start_addr, &end_addr); 447 *addr = reinterpret_cast<uptr>(start_addr); 448 *size = 449 reinterpret_cast<uptr>(end_addr) - reinterpret_cast<uptr>(start_addr); 450 } else { 451 *addr = 0; 452 *size = 0; 453 } 454 #elif SANITIZER_GLIBC && defined(__x86_64__) 455 // For aarch64 and x86-64, use an O(1) approach which requires relatively 456 // precise ThreadDescriptorSize. g_tls_size was initialized in InitTlsSize. 457 asm("mov %%fs:16,%0" : "=r"(*addr)); 458 *size = g_tls_size; 459 *addr -= *size; 460 *addr += ThreadDescriptorSize(); 461 #elif SANITIZER_GLIBC && defined(__aarch64__) 462 *addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) - 463 ThreadDescriptorSize(); 464 *size = g_tls_size + ThreadDescriptorSize(); 465 #elif SANITIZER_GLIBC && defined(__powerpc64__) 466 // Workaround for glibc<2.25(?). 2.27 is known to not need this. 467 uptr tp; 468 asm("addi %0,13,-0x7000" : "=r"(tp)); 469 const uptr pre_tcb_size = TlsPreTcbSize(); 470 *addr = tp - pre_tcb_size; 471 *size = g_tls_size + pre_tcb_size; 472 #elif SANITIZER_FREEBSD || SANITIZER_LINUX 473 uptr align; 474 GetStaticTlsBoundary(addr, size, &align); 475 #if defined(__x86_64__) || defined(__i386__) || defined(__s390__) || \ 476 defined(__sparc__) 477 if (SANITIZER_GLIBC) { 478 #if defined(__x86_64__) || defined(__i386__) 479 align = Max<uptr>(align, 64); 480 #else 481 align = Max<uptr>(align, 16); 482 #endif 483 } 484 const uptr tp = RoundUpTo(*addr + *size, align); 485 486 // lsan requires the range to additionally cover the static TLS surplus 487 // (elf/dl-tls.c defines 1664). Otherwise there may be false positives for 488 // allocations only referenced by tls in dynamically loaded modules. 489 if (SANITIZER_GLIBC) 490 *size += 1644; 491 else if (SANITIZER_FREEBSD) 492 *size += 128; // RTLD_STATIC_TLS_EXTRA 493 494 // Extend the range to include the thread control block. On glibc, lsan needs 495 // the range to include pthread::{specific_1stblock,specific} so that 496 // allocations only referenced by pthread_setspecific can be scanned. This may 497 // underestimate by at most TLS_TCB_ALIGN-1 bytes but it should be fine 498 // because the number of bytes after pthread::specific is larger. 499 *addr = tp - RoundUpTo(*size, align); 500 *size = tp - *addr + ThreadDescriptorSize(); 501 #else 502 if (SANITIZER_GLIBC) 503 *size += 1664; 504 else if (SANITIZER_FREEBSD) 505 *size += 128; // RTLD_STATIC_TLS_EXTRA 506 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 507 const uptr pre_tcb_size = TlsPreTcbSize(); 508 *addr -= pre_tcb_size; 509 *size += pre_tcb_size; 510 #else 511 // arm and aarch64 reserve two words at TP, so this underestimates the range. 512 // However, this is sufficient for the purpose of finding the pointers to 513 // thread-specific data keys. 514 const uptr tcb_size = ThreadDescriptorSize(); 515 *addr -= tcb_size; 516 *size += tcb_size; 517 #endif 518 #endif 519 #elif SANITIZER_NETBSD 520 struct tls_tcb * const tcb = ThreadSelfTlsTcb(); 521 *addr = 0; 522 *size = 0; 523 if (tcb != 0) { 524 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program). 525 // ld.elf_so hardcodes the index 1. 526 dl_iterate_phdr(GetSizeFromHdr, size); 527 528 if (*size != 0) { 529 // The block has been found and tcb_dtv[1] contains the base address 530 *addr = (uptr)tcb->tcb_dtv[1]; 531 } 532 } 533 #elif SANITIZER_SOLARIS 534 // FIXME 535 *addr = 0; 536 *size = 0; 537 #else 538 #error "Unknown OS" 539 #endif 540 } 541 #endif 542 543 #if !SANITIZER_GO 544 uptr GetTlsSize() { 545 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \ 546 SANITIZER_SOLARIS 547 uptr addr, size; 548 GetTls(&addr, &size); 549 return size; 550 #else 551 return 0; 552 #endif 553 } 554 #endif 555 556 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, 557 uptr *tls_addr, uptr *tls_size) { 558 #if SANITIZER_GO 559 // Stub implementation for Go. 560 *stk_addr = *stk_size = *tls_addr = *tls_size = 0; 561 #else 562 GetTls(tls_addr, tls_size); 563 564 uptr stack_top, stack_bottom; 565 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); 566 *stk_addr = stack_bottom; 567 *stk_size = stack_top - stack_bottom; 568 569 if (!main) { 570 // If stack and tls intersect, make them non-intersecting. 571 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { 572 if (*stk_addr + *stk_size < *tls_addr + *tls_size) 573 *tls_size = *stk_addr + *stk_size - *tls_addr; 574 *stk_size = *tls_addr - *stk_addr; 575 } 576 } 577 #endif 578 } 579 580 #if !SANITIZER_FREEBSD 581 typedef ElfW(Phdr) Elf_Phdr; 582 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2 583 #define Elf_Phdr XElf32_Phdr 584 #define dl_phdr_info xdl_phdr_info 585 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b)) 586 #endif // !SANITIZER_FREEBSD 587 588 struct DlIteratePhdrData { 589 InternalMmapVectorNoCtor<LoadedModule> *modules; 590 bool first; 591 }; 592 593 static int AddModuleSegments(const char *module_name, dl_phdr_info *info, 594 InternalMmapVectorNoCtor<LoadedModule> *modules) { 595 if (module_name[0] == '\0') 596 return 0; 597 LoadedModule cur_module; 598 cur_module.set(module_name, info->dlpi_addr); 599 for (int i = 0; i < (int)info->dlpi_phnum; i++) { 600 const Elf_Phdr *phdr = &info->dlpi_phdr[i]; 601 if (phdr->p_type == PT_LOAD) { 602 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr; 603 uptr cur_end = cur_beg + phdr->p_memsz; 604 bool executable = phdr->p_flags & PF_X; 605 bool writable = phdr->p_flags & PF_W; 606 cur_module.addAddressRange(cur_beg, cur_end, executable, 607 writable); 608 } 609 } 610 modules->push_back(cur_module); 611 return 0; 612 } 613 614 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) { 615 DlIteratePhdrData *data = (DlIteratePhdrData *)arg; 616 if (data->first) { 617 InternalMmapVector<char> module_name(kMaxPathLength); 618 data->first = false; 619 // First module is the binary itself. 620 ReadBinaryNameCached(module_name.data(), module_name.size()); 621 return AddModuleSegments(module_name.data(), info, data->modules); 622 } 623 624 if (info->dlpi_name) { 625 InternalScopedString module_name; 626 module_name.append("%s", info->dlpi_name); 627 return AddModuleSegments(module_name.data(), info, data->modules); 628 } 629 630 return 0; 631 } 632 633 #if SANITIZER_ANDROID && __ANDROID_API__ < 21 634 extern "C" __attribute__((weak)) int dl_iterate_phdr( 635 int (*)(struct dl_phdr_info *, size_t, void *), void *); 636 #endif 637 638 static bool requiresProcmaps() { 639 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22 640 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken. 641 // The runtime check allows the same library to work with 642 // both K and L (and future) Android releases. 643 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1; 644 #else 645 return false; 646 #endif 647 } 648 649 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) { 650 MemoryMappingLayout memory_mapping(/*cache_enabled*/true); 651 memory_mapping.DumpListOfModules(modules); 652 } 653 654 void ListOfModules::init() { 655 clearOrInit(); 656 if (requiresProcmaps()) { 657 procmapsInit(&modules_); 658 } else { 659 DlIteratePhdrData data = {&modules_, true}; 660 dl_iterate_phdr(dl_iterate_phdr_cb, &data); 661 } 662 } 663 664 // When a custom loader is used, dl_iterate_phdr may not contain the full 665 // list of modules. Allow callers to fall back to using procmaps. 666 void ListOfModules::fallbackInit() { 667 if (!requiresProcmaps()) { 668 clearOrInit(); 669 procmapsInit(&modules_); 670 } else { 671 clear(); 672 } 673 } 674 675 // getrusage does not give us the current RSS, only the max RSS. 676 // Still, this is better than nothing if /proc/self/statm is not available 677 // for some reason, e.g. due to a sandbox. 678 static uptr GetRSSFromGetrusage() { 679 struct rusage usage; 680 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox. 681 return 0; 682 return usage.ru_maxrss << 10; // ru_maxrss is in Kb. 683 } 684 685 uptr GetRSS() { 686 if (!common_flags()->can_use_proc_maps_statm) 687 return GetRSSFromGetrusage(); 688 fd_t fd = OpenFile("/proc/self/statm", RdOnly); 689 if (fd == kInvalidFd) 690 return GetRSSFromGetrusage(); 691 char buf[64]; 692 uptr len = internal_read(fd, buf, sizeof(buf) - 1); 693 internal_close(fd); 694 if ((sptr)len <= 0) 695 return 0; 696 buf[len] = 0; 697 // The format of the file is: 698 // 1084 89 69 11 0 79 0 699 // We need the second number which is RSS in pages. 700 char *pos = buf; 701 // Skip the first number. 702 while (*pos >= '0' && *pos <= '9') 703 pos++; 704 // Skip whitespaces. 705 while (!(*pos >= '0' && *pos <= '9') && *pos != 0) 706 pos++; 707 // Read the number. 708 uptr rss = 0; 709 while (*pos >= '0' && *pos <= '9') 710 rss = rss * 10 + *pos++ - '0'; 711 return rss * GetPageSizeCached(); 712 } 713 714 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as 715 // they allocate memory. 716 u32 GetNumberOfCPUs() { 717 #if SANITIZER_FREEBSD || SANITIZER_NETBSD 718 u32 ncpu; 719 int req[2]; 720 uptr len = sizeof(ncpu); 721 req[0] = CTL_HW; 722 req[1] = HW_NCPU; 723 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0); 724 return ncpu; 725 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__) 726 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't 727 // exist in sched.h. That is the case for toolchains generated with older 728 // NDKs. 729 // This code doesn't work on AArch64 because internal_getdents makes use of 730 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64. 731 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY); 732 if (internal_iserror(fd)) 733 return 0; 734 InternalMmapVector<u8> buffer(4096); 735 uptr bytes_read = buffer.size(); 736 uptr n_cpus = 0; 737 u8 *d_type; 738 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read]; 739 while (true) { 740 if ((u8 *)entry >= &buffer[bytes_read]) { 741 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(), 742 buffer.size()); 743 if (internal_iserror(bytes_read) || !bytes_read) 744 break; 745 entry = (struct linux_dirent *)buffer.data(); 746 } 747 d_type = (u8 *)entry + entry->d_reclen - 1; 748 if (d_type >= &buffer[bytes_read] || 749 (u8 *)&entry->d_name[3] >= &buffer[bytes_read]) 750 break; 751 if (entry->d_ino != 0 && *d_type == DT_DIR) { 752 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' && 753 entry->d_name[2] == 'u' && 754 entry->d_name[3] >= '0' && entry->d_name[3] <= '9') 755 n_cpus++; 756 } 757 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen); 758 } 759 internal_close(fd); 760 return n_cpus; 761 #elif SANITIZER_SOLARIS 762 return sysconf(_SC_NPROCESSORS_ONLN); 763 #else 764 cpu_set_t CPUs; 765 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0); 766 return CPU_COUNT(&CPUs); 767 #endif 768 } 769 770 #if SANITIZER_LINUX 771 772 #if SANITIZER_ANDROID 773 static atomic_uint8_t android_log_initialized; 774 775 void AndroidLogInit() { 776 openlog(GetProcessName(), 0, LOG_USER); 777 atomic_store(&android_log_initialized, 1, memory_order_release); 778 } 779 780 static bool ShouldLogAfterPrintf() { 781 return atomic_load(&android_log_initialized, memory_order_acquire); 782 } 783 784 extern "C" SANITIZER_WEAK_ATTRIBUTE 785 int async_safe_write_log(int pri, const char* tag, const char* msg); 786 extern "C" SANITIZER_WEAK_ATTRIBUTE 787 int __android_log_write(int prio, const char* tag, const char* msg); 788 789 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime. 790 #define SANITIZER_ANDROID_LOG_INFO 4 791 792 // async_safe_write_log is a new public version of __libc_write_log that is 793 // used behind syslog. It is preferable to syslog as it will not do any dynamic 794 // memory allocation or formatting. 795 // If the function is not available, syslog is preferred for L+ (it was broken 796 // pre-L) as __android_log_write triggers a racey behavior with the strncpy 797 // interceptor. Fallback to __android_log_write pre-L. 798 void WriteOneLineToSyslog(const char *s) { 799 if (&async_safe_write_log) { 800 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s); 801 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) { 802 syslog(LOG_INFO, "%s", s); 803 } else { 804 CHECK(&__android_log_write); 805 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s); 806 } 807 } 808 809 extern "C" SANITIZER_WEAK_ATTRIBUTE 810 void android_set_abort_message(const char *); 811 812 void SetAbortMessage(const char *str) { 813 if (&android_set_abort_message) 814 android_set_abort_message(str); 815 } 816 #else 817 void AndroidLogInit() {} 818 819 static bool ShouldLogAfterPrintf() { return true; } 820 821 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); } 822 823 void SetAbortMessage(const char *str) {} 824 #endif // SANITIZER_ANDROID 825 826 void LogMessageOnPrintf(const char *str) { 827 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf()) 828 WriteToSyslog(str); 829 } 830 831 #endif // SANITIZER_LINUX 832 833 #if SANITIZER_GLIBC && !SANITIZER_GO 834 // glibc crashes when using clock_gettime from a preinit_array function as the 835 // vDSO function pointers haven't been initialized yet. __progname is 836 // initialized after the vDSO function pointers, so if it exists, is not null 837 // and is not empty, we can use clock_gettime. 838 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname; 839 inline bool CanUseVDSO() { return &__progname && __progname && *__progname; } 840 841 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling 842 // clock_gettime. real_clock_gettime only exists if clock_gettime is 843 // intercepted, so define it weakly and use it if available. 844 extern "C" SANITIZER_WEAK_ATTRIBUTE 845 int real_clock_gettime(u32 clk_id, void *tp); 846 u64 MonotonicNanoTime() { 847 timespec ts; 848 if (CanUseVDSO()) { 849 if (&real_clock_gettime) 850 real_clock_gettime(CLOCK_MONOTONIC, &ts); 851 else 852 clock_gettime(CLOCK_MONOTONIC, &ts); 853 } else { 854 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 855 } 856 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 857 } 858 #else 859 // Non-glibc & Go always use the regular function. 860 u64 MonotonicNanoTime() { 861 timespec ts; 862 clock_gettime(CLOCK_MONOTONIC, &ts); 863 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 864 } 865 #endif // SANITIZER_GLIBC && !SANITIZER_GO 866 867 void ReExec() { 868 const char *pathname = "/proc/self/exe"; 869 870 #if SANITIZER_FREEBSD 871 char exe_path[PATH_MAX]; 872 if (elf_aux_info(AT_EXECPATH, exe_path, sizeof(exe_path)) == 0) { 873 char link_path[PATH_MAX]; 874 if (realpath(exe_path, link_path)) 875 pathname = link_path; 876 } 877 #elif SANITIZER_NETBSD 878 static const int name[] = { 879 CTL_KERN, 880 KERN_PROC_ARGS, 881 -1, 882 KERN_PROC_PATHNAME, 883 }; 884 char path[400]; 885 uptr len; 886 887 len = sizeof(path); 888 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1) 889 pathname = path; 890 #elif SANITIZER_SOLARIS 891 pathname = getexecname(); 892 CHECK_NE(pathname, NULL); 893 #elif SANITIZER_USE_GETAUXVAL 894 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that 895 // rely on that will fail to load shared libraries. Query AT_EXECFN instead. 896 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN)); 897 #endif 898 899 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron()); 900 int rverrno; 901 CHECK_EQ(internal_iserror(rv, &rverrno), true); 902 Printf("execve failed, errno %d\n", rverrno); 903 Die(); 904 } 905 906 void UnmapFromTo(uptr from, uptr to) { 907 if (to == from) 908 return; 909 CHECK(to >= from); 910 uptr res = internal_munmap(reinterpret_cast<void *>(from), to - from); 911 if (UNLIKELY(internal_iserror(res))) { 912 Report("ERROR: %s failed to unmap 0x%zx (%zd) bytes at address %p\n", 913 SanitizerToolName, to - from, to - from, (void *)from); 914 CHECK("unable to unmap" && 0); 915 } 916 } 917 918 uptr MapDynamicShadow(uptr shadow_size_bytes, uptr shadow_scale, 919 uptr min_shadow_base_alignment, 920 UNUSED uptr &high_mem_end) { 921 const uptr granularity = GetMmapGranularity(); 922 const uptr alignment = 923 Max<uptr>(granularity << shadow_scale, 1ULL << min_shadow_base_alignment); 924 const uptr left_padding = 925 Max<uptr>(granularity, 1ULL << min_shadow_base_alignment); 926 927 const uptr shadow_size = RoundUpTo(shadow_size_bytes, granularity); 928 const uptr map_size = shadow_size + left_padding + alignment; 929 930 const uptr map_start = (uptr)MmapNoAccess(map_size); 931 CHECK_NE(map_start, ~(uptr)0); 932 933 const uptr shadow_start = RoundUpTo(map_start + left_padding, alignment); 934 935 UnmapFromTo(map_start, shadow_start - left_padding); 936 UnmapFromTo(shadow_start + shadow_size, map_start + map_size); 937 938 return shadow_start; 939 } 940 941 static uptr MmapSharedNoReserve(uptr addr, uptr size) { 942 return internal_mmap( 943 reinterpret_cast<void *>(addr), size, PROT_READ | PROT_WRITE, 944 MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0); 945 } 946 947 static uptr MremapCreateAlias(uptr base_addr, uptr alias_addr, 948 uptr alias_size) { 949 #if SANITIZER_LINUX 950 return internal_mremap(reinterpret_cast<void *>(base_addr), 0, alias_size, 951 MREMAP_MAYMOVE | MREMAP_FIXED, 952 reinterpret_cast<void *>(alias_addr)); 953 #else 954 CHECK(false && "mremap is not supported outside of Linux"); 955 return 0; 956 #endif 957 } 958 959 static void CreateAliases(uptr start_addr, uptr alias_size, uptr num_aliases) { 960 uptr total_size = alias_size * num_aliases; 961 uptr mapped = MmapSharedNoReserve(start_addr, total_size); 962 CHECK_EQ(mapped, start_addr); 963 964 for (uptr i = 1; i < num_aliases; ++i) { 965 uptr alias_addr = start_addr + i * alias_size; 966 CHECK_EQ(MremapCreateAlias(start_addr, alias_addr, alias_size), alias_addr); 967 } 968 } 969 970 uptr MapDynamicShadowAndAliases(uptr shadow_size, uptr alias_size, 971 uptr num_aliases, uptr ring_buffer_size) { 972 CHECK_EQ(alias_size & (alias_size - 1), 0); 973 CHECK_EQ(num_aliases & (num_aliases - 1), 0); 974 CHECK_EQ(ring_buffer_size & (ring_buffer_size - 1), 0); 975 976 const uptr granularity = GetMmapGranularity(); 977 shadow_size = RoundUpTo(shadow_size, granularity); 978 CHECK_EQ(shadow_size & (shadow_size - 1), 0); 979 980 const uptr alias_region_size = alias_size * num_aliases; 981 const uptr alignment = 982 2 * Max(Max(shadow_size, alias_region_size), ring_buffer_size); 983 const uptr left_padding = ring_buffer_size; 984 985 const uptr right_size = alignment; 986 const uptr map_size = left_padding + 2 * alignment; 987 988 const uptr map_start = reinterpret_cast<uptr>(MmapNoAccess(map_size)); 989 CHECK_NE(map_start, static_cast<uptr>(-1)); 990 const uptr right_start = RoundUpTo(map_start + left_padding, alignment); 991 992 UnmapFromTo(map_start, right_start - left_padding); 993 UnmapFromTo(right_start + right_size, map_start + map_size); 994 995 CreateAliases(right_start + right_size / 2, alias_size, num_aliases); 996 997 return right_start; 998 } 999 1000 void InitializePlatformCommonFlags(CommonFlags *cf) { 1001 #if SANITIZER_ANDROID 1002 if (&__libc_get_static_tls_bounds == nullptr) 1003 cf->detect_leaks = false; 1004 #endif 1005 } 1006 1007 } // namespace __sanitizer 1008 1009 #endif 1010