1 //===-- sanitizer_linux_libcdep.cpp ---------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is shared between AddressSanitizer and ThreadSanitizer 10 // run-time libraries and implements linux-specific functions from 11 // sanitizer_libc.h. 12 //===----------------------------------------------------------------------===// 13 14 #include "sanitizer_platform.h" 15 16 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \ 17 SANITIZER_OPENBSD || SANITIZER_SOLARIS 18 19 #include "sanitizer_allocator_internal.h" 20 #include "sanitizer_atomic.h" 21 #include "sanitizer_common.h" 22 #include "sanitizer_file.h" 23 #include "sanitizer_flags.h" 24 #include "sanitizer_freebsd.h" 25 #include "sanitizer_getauxval.h" 26 #include "sanitizer_glibc_version.h" 27 #include "sanitizer_linux.h" 28 #include "sanitizer_placement_new.h" 29 #include "sanitizer_procmaps.h" 30 31 #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/resource.h> 40 #include <syslog.h> 41 42 #if !defined(ElfW) 43 #define ElfW(type) Elf_##type 44 #endif 45 46 #if SANITIZER_FREEBSD 47 #include <pthread_np.h> 48 #include <osreldate.h> 49 #include <sys/sysctl.h> 50 #define pthread_getattr_np pthread_attr_get_np 51 #endif 52 53 #if SANITIZER_OPENBSD 54 #include <pthread_np.h> 55 #include <sys/sysctl.h> 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 #elif SANITIZER_OPENBSD 146 stack_t sattr; 147 CHECK_EQ(pthread_stackseg_np(pthread_self(), &sattr), 0); 148 stackaddr = sattr.ss_sp; 149 stacksize = sattr.ss_size; 150 #else // !SANITIZER_SOLARIS 151 pthread_attr_t attr; 152 pthread_attr_init(&attr); 153 CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0); 154 my_pthread_attr_getstack(&attr, &stackaddr, &stacksize); 155 pthread_attr_destroy(&attr); 156 #endif // SANITIZER_SOLARIS 157 158 *stack_top = (uptr)stackaddr + stacksize; 159 *stack_bottom = (uptr)stackaddr; 160 } 161 162 #if !SANITIZER_GO 163 bool SetEnv(const char *name, const char *value) { 164 void *f = dlsym(RTLD_NEXT, "setenv"); 165 if (!f) 166 return false; 167 typedef int(*setenv_ft)(const char *name, const char *value, int overwrite); 168 setenv_ft setenv_f; 169 CHECK_EQ(sizeof(setenv_f), sizeof(f)); 170 internal_memcpy(&setenv_f, &f, sizeof(f)); 171 return setenv_f(name, value, 1) == 0; 172 } 173 #endif 174 175 __attribute__((unused)) static bool GetLibcVersion(int *major, int *minor, 176 int *patch) { 177 #ifdef _CS_GNU_LIBC_VERSION 178 char buf[64]; 179 uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf)); 180 if (len >= sizeof(buf)) 181 return false; 182 buf[len] = 0; 183 static const char kGLibC[] = "glibc "; 184 if (internal_strncmp(buf, kGLibC, sizeof(kGLibC) - 1) != 0) 185 return false; 186 const char *p = buf + sizeof(kGLibC) - 1; 187 *major = internal_simple_strtoll(p, &p, 10); 188 *minor = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 189 *patch = (*p == '.') ? internal_simple_strtoll(p + 1, &p, 10) : 0; 190 return true; 191 #else 192 return false; 193 #endif 194 } 195 196 #if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO && \ 197 !SANITIZER_NETBSD && !SANITIZER_OPENBSD && !SANITIZER_SOLARIS 198 static uptr g_tls_size; 199 200 #ifdef __i386__ 201 #define CHECK_GET_TLS_STATIC_INFO_VERSION (!__GLIBC_PREREQ(2, 27)) 202 #else 203 #define CHECK_GET_TLS_STATIC_INFO_VERSION 0 204 #endif 205 206 #if CHECK_GET_TLS_STATIC_INFO_VERSION 207 #define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall)) 208 #else 209 #define DL_INTERNAL_FUNCTION 210 #endif 211 212 namespace { 213 struct GetTlsStaticInfoCall { 214 typedef void (*get_tls_func)(size_t*, size_t*); 215 }; 216 struct GetTlsStaticInfoRegparmCall { 217 typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION; 218 }; 219 220 template <typename T> 221 void CallGetTls(void* ptr, size_t* size, size_t* align) { 222 typename T::get_tls_func get_tls; 223 CHECK_EQ(sizeof(get_tls), sizeof(ptr)); 224 internal_memcpy(&get_tls, &ptr, sizeof(ptr)); 225 CHECK_NE(get_tls, 0); 226 get_tls(size, align); 227 } 228 229 bool CmpLibcVersion(int major, int minor, int patch) { 230 int ma; 231 int mi; 232 int pa; 233 if (!GetLibcVersion(&ma, &mi, &pa)) 234 return false; 235 if (ma > major) 236 return true; 237 if (ma < major) 238 return false; 239 if (mi > minor) 240 return true; 241 if (mi < minor) 242 return false; 243 return pa >= patch; 244 } 245 246 } // namespace 247 248 void InitTlsSize() { 249 // all current supported platforms have 16 bytes stack alignment 250 const size_t kStackAlign = 16; 251 void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info"); 252 size_t tls_size = 0; 253 size_t tls_align = 0; 254 // On i?86, _dl_get_tls_static_info used to be internal_function, i.e. 255 // __attribute__((regparm(3), stdcall)) before glibc 2.27 and is normal 256 // function in 2.27 and later. 257 if (CHECK_GET_TLS_STATIC_INFO_VERSION && !CmpLibcVersion(2, 27, 0)) 258 CallGetTls<GetTlsStaticInfoRegparmCall>(get_tls_static_info_ptr, 259 &tls_size, &tls_align); 260 else 261 CallGetTls<GetTlsStaticInfoCall>(get_tls_static_info_ptr, 262 &tls_size, &tls_align); 263 if (tls_align < kStackAlign) 264 tls_align = kStackAlign; 265 g_tls_size = RoundUpTo(tls_size, tls_align); 266 } 267 #else 268 void InitTlsSize() { } 269 #endif 270 271 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) || \ 272 defined(__aarch64__) || defined(__powerpc64__) || defined(__s390__) || \ 273 defined(__arm__) || SANITIZER_RISCV64) && \ 274 SANITIZER_LINUX && !SANITIZER_ANDROID 275 // sizeof(struct pthread) from glibc. 276 static atomic_uintptr_t thread_descriptor_size; 277 278 uptr ThreadDescriptorSize() { 279 uptr val = atomic_load_relaxed(&thread_descriptor_size); 280 if (val) 281 return val; 282 #if defined(__x86_64__) || defined(__i386__) || defined(__arm__) 283 int major; 284 int minor; 285 int patch; 286 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 287 /* sizeof(struct pthread) values from various glibc versions. */ 288 if (SANITIZER_X32) 289 val = 1728; // Assume only one particular version for x32. 290 // For ARM sizeof(struct pthread) changed in Glibc 2.23. 291 else if (SANITIZER_ARM) 292 val = minor <= 22 ? 1120 : 1216; 293 else if (minor <= 3) 294 val = FIRST_32_SECOND_64(1104, 1696); 295 else if (minor == 4) 296 val = FIRST_32_SECOND_64(1120, 1728); 297 else if (minor == 5) 298 val = FIRST_32_SECOND_64(1136, 1728); 299 else if (minor <= 9) 300 val = FIRST_32_SECOND_64(1136, 1712); 301 else if (minor == 10) 302 val = FIRST_32_SECOND_64(1168, 1776); 303 else if (minor == 11 || (minor == 12 && patch == 1)) 304 val = FIRST_32_SECOND_64(1168, 2288); 305 else if (minor <= 14) 306 val = FIRST_32_SECOND_64(1168, 2304); 307 else 308 val = FIRST_32_SECOND_64(1216, 2304); 309 } 310 #elif defined(__mips__) 311 // TODO(sagarthakur): add more values as per different glibc versions. 312 val = FIRST_32_SECOND_64(1152, 1776); 313 #elif SANITIZER_RISCV64 314 int major; 315 int minor; 316 int patch; 317 if (GetLibcVersion(&major, &minor, &patch) && major == 2) { 318 // TODO: consider adding an optional runtime check for an unknown (untested) 319 // glibc version 320 if (minor <= 28) // WARNING: the highest tested version is 2.29 321 val = 1772; // no guarantees for this one 322 else if (minor <= 31) 323 val = 1772; // tested against glibc 2.29, 2.31 324 else 325 val = 1936; // tested against glibc 2.32 326 } 327 328 #elif defined(__aarch64__) 329 // The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22. 330 val = 1776; 331 #elif defined(__powerpc64__) 332 val = 1776; // from glibc.ppc64le 2.20-8.fc21 333 #elif defined(__s390__) 334 val = FIRST_32_SECOND_64(1152, 1776); // valid for glibc 2.22 335 #endif 336 if (val) 337 atomic_store_relaxed(&thread_descriptor_size, val); 338 return val; 339 } 340 341 // The offset at which pointer to self is located in the thread descriptor. 342 const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16); 343 344 uptr ThreadSelfOffset() { 345 return kThreadSelfOffset; 346 } 347 348 #if defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 349 // TlsPreTcbSize includes size of struct pthread_descr and size of tcb 350 // head structure. It lies before the static tls blocks. 351 static uptr TlsPreTcbSize() { 352 #if defined(__mips__) 353 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 354 #elif defined(__powerpc64__) 355 const uptr kTcbHead = 88; // sizeof (tcbhead_t) 356 #elif SANITIZER_RISCV64 357 const uptr kTcbHead = 16; // sizeof (tcbhead_t) 358 #endif 359 const uptr kTlsAlign = 16; 360 const uptr kTlsPreTcbSize = 361 RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign); 362 return kTlsPreTcbSize; 363 } 364 #endif 365 366 uptr ThreadSelf() { 367 uptr descr_addr; 368 #if defined(__i386__) 369 asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 370 #elif defined(__x86_64__) 371 asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset)); 372 #elif defined(__mips__) 373 // MIPS uses TLS variant I. The thread pointer (in hardware register $29) 374 // points to the end of the TCB + 0x7000. The pthread_descr structure is 375 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 376 // TCB and the size of pthread_descr. 377 const uptr kTlsTcbOffset = 0x7000; 378 uptr thread_pointer; 379 asm volatile(".set push;\ 380 .set mips64r2;\ 381 rdhwr %0,$29;\ 382 .set pop" : "=r" (thread_pointer)); 383 descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize(); 384 #elif defined(__aarch64__) || defined(__arm__) 385 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) - 386 ThreadDescriptorSize(); 387 #elif SANITIZER_RISCV64 388 uptr tcb_end; 389 asm volatile("mv %0, tp;\n" : "=r"(tcb_end)); 390 // https://github.com/riscv/riscv-elf-psabi-doc/issues/53 391 const uptr kTlsTcbOffset = 0x800; 392 descr_addr = 393 reinterpret_cast<uptr>(tcb_end - kTlsTcbOffset - TlsPreTcbSize()); 394 #elif defined(__s390__) 395 descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()); 396 #elif defined(__powerpc64__) 397 // PPC64LE uses TLS variant I. The thread pointer (in GPR 13) 398 // points to the end of the TCB + 0x7000. The pthread_descr structure is 399 // immediately in front of the TCB. TlsPreTcbSize() includes the size of the 400 // TCB and the size of pthread_descr. 401 const uptr kTlsTcbOffset = 0x7000; 402 uptr thread_pointer; 403 asm("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset)); 404 descr_addr = thread_pointer - TlsPreTcbSize(); 405 #else 406 #error "unsupported CPU arch" 407 #endif 408 return descr_addr; 409 } 410 #endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX 411 412 #if SANITIZER_FREEBSD 413 static void **ThreadSelfSegbase() { 414 void **segbase = 0; 415 #if defined(__i386__) 416 // sysarch(I386_GET_GSBASE, segbase); 417 __asm __volatile("mov %%gs:0, %0" : "=r" (segbase)); 418 #elif defined(__x86_64__) 419 // sysarch(AMD64_GET_FSBASE, segbase); 420 __asm __volatile("movq %%fs:0, %0" : "=r" (segbase)); 421 #else 422 #error "unsupported CPU arch" 423 #endif 424 return segbase; 425 } 426 427 uptr ThreadSelf() { 428 return (uptr)ThreadSelfSegbase()[2]; 429 } 430 #endif // SANITIZER_FREEBSD 431 432 #if SANITIZER_NETBSD 433 static struct tls_tcb * ThreadSelfTlsTcb() { 434 struct tls_tcb *tcb = nullptr; 435 #ifdef __HAVE___LWP_GETTCB_FAST 436 tcb = (struct tls_tcb *)__lwp_gettcb_fast(); 437 #elif defined(__HAVE___LWP_GETPRIVATE_FAST) 438 tcb = (struct tls_tcb *)__lwp_getprivate_fast(); 439 #endif 440 return tcb; 441 } 442 443 uptr ThreadSelf() { 444 return (uptr)ThreadSelfTlsTcb()->tcb_pthread; 445 } 446 447 int GetSizeFromHdr(struct dl_phdr_info *info, size_t size, void *data) { 448 const Elf_Phdr *hdr = info->dlpi_phdr; 449 const Elf_Phdr *last_hdr = hdr + info->dlpi_phnum; 450 451 for (; hdr != last_hdr; ++hdr) { 452 if (hdr->p_type == PT_TLS && info->dlpi_tls_modid == 1) { 453 *(uptr*)data = hdr->p_memsz; 454 break; 455 } 456 } 457 return 0; 458 } 459 #endif // SANITIZER_NETBSD 460 461 #if !SANITIZER_GO 462 static void GetTls(uptr *addr, uptr *size) { 463 #if SANITIZER_LINUX && !SANITIZER_ANDROID 464 #if defined(__x86_64__) || defined(__i386__) || defined(__s390__) 465 *addr = ThreadSelf(); 466 *size = GetTlsSize(); 467 *addr -= *size; 468 *addr += ThreadDescriptorSize(); 469 #elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__) || \ 470 defined(__arm__) || SANITIZER_RISCV64 471 *addr = ThreadSelf(); 472 *size = GetTlsSize(); 473 #else 474 *addr = 0; 475 *size = 0; 476 #endif 477 #elif SANITIZER_FREEBSD 478 void** segbase = ThreadSelfSegbase(); 479 *addr = 0; 480 *size = 0; 481 if (segbase != 0) { 482 // tcbalign = 16 483 // tls_size = round(tls_static_space, tcbalign); 484 // dtv = segbase[1]; 485 // dtv[2] = segbase - tls_static_space; 486 void **dtv = (void**) segbase[1]; 487 *addr = (uptr) dtv[2]; 488 *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]); 489 } 490 #elif SANITIZER_NETBSD 491 struct tls_tcb * const tcb = ThreadSelfTlsTcb(); 492 *addr = 0; 493 *size = 0; 494 if (tcb != 0) { 495 // Find size (p_memsz) of dlpi_tls_modid 1 (TLS block of the main program). 496 // ld.elf_so hardcodes the index 1. 497 dl_iterate_phdr(GetSizeFromHdr, size); 498 499 if (*size != 0) { 500 // The block has been found and tcb_dtv[1] contains the base address 501 *addr = (uptr)tcb->tcb_dtv[1]; 502 } 503 } 504 #elif SANITIZER_OPENBSD 505 *addr = 0; 506 *size = 0; 507 #elif SANITIZER_ANDROID 508 *addr = 0; 509 *size = 0; 510 #elif SANITIZER_SOLARIS 511 // FIXME 512 *addr = 0; 513 *size = 0; 514 #else 515 #error "Unknown OS" 516 #endif 517 } 518 #endif 519 520 #if !SANITIZER_GO 521 uptr GetTlsSize() { 522 #if SANITIZER_FREEBSD || SANITIZER_ANDROID || SANITIZER_NETBSD || \ 523 SANITIZER_OPENBSD || SANITIZER_SOLARIS 524 uptr addr, size; 525 GetTls(&addr, &size); 526 return size; 527 #elif defined(__mips__) || defined(__powerpc64__) || SANITIZER_RISCV64 528 return RoundUpTo(g_tls_size + TlsPreTcbSize(), 16); 529 #else 530 return g_tls_size; 531 #endif 532 } 533 #endif 534 535 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size, 536 uptr *tls_addr, uptr *tls_size) { 537 #if SANITIZER_GO 538 // Stub implementation for Go. 539 *stk_addr = *stk_size = *tls_addr = *tls_size = 0; 540 #else 541 GetTls(tls_addr, tls_size); 542 543 uptr stack_top, stack_bottom; 544 GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom); 545 *stk_addr = stack_bottom; 546 *stk_size = stack_top - stack_bottom; 547 548 if (!main) { 549 // If stack and tls intersect, make them non-intersecting. 550 if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) { 551 CHECK_GT(*tls_addr + *tls_size, *stk_addr); 552 CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size); 553 *stk_size -= *tls_size; 554 *tls_addr = *stk_addr + *stk_size; 555 } 556 } 557 #endif 558 } 559 560 #if !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 561 typedef ElfW(Phdr) Elf_Phdr; 562 #elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2 563 #define Elf_Phdr XElf32_Phdr 564 #define dl_phdr_info xdl_phdr_info 565 #define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b)) 566 #endif // !SANITIZER_FREEBSD && !SANITIZER_OPENBSD 567 568 struct DlIteratePhdrData { 569 InternalMmapVectorNoCtor<LoadedModule> *modules; 570 bool first; 571 }; 572 573 static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) { 574 DlIteratePhdrData *data = (DlIteratePhdrData*)arg; 575 InternalScopedString module_name(kMaxPathLength); 576 if (data->first) { 577 data->first = false; 578 // First module is the binary itself. 579 ReadBinaryNameCached(module_name.data(), module_name.size()); 580 } else if (info->dlpi_name) { 581 module_name.append("%s", info->dlpi_name); 582 } 583 if (module_name[0] == '\0') 584 return 0; 585 LoadedModule cur_module; 586 cur_module.set(module_name.data(), info->dlpi_addr); 587 for (int i = 0; i < (int)info->dlpi_phnum; i++) { 588 const Elf_Phdr *phdr = &info->dlpi_phdr[i]; 589 if (phdr->p_type == PT_LOAD) { 590 uptr cur_beg = info->dlpi_addr + phdr->p_vaddr; 591 uptr cur_end = cur_beg + phdr->p_memsz; 592 bool executable = phdr->p_flags & PF_X; 593 bool writable = phdr->p_flags & PF_W; 594 cur_module.addAddressRange(cur_beg, cur_end, executable, 595 writable); 596 } 597 } 598 data->modules->push_back(cur_module); 599 return 0; 600 } 601 602 #if SANITIZER_ANDROID && __ANDROID_API__ < 21 603 extern "C" __attribute__((weak)) int dl_iterate_phdr( 604 int (*)(struct dl_phdr_info *, size_t, void *), void *); 605 #endif 606 607 static bool requiresProcmaps() { 608 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22 609 // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken. 610 // The runtime check allows the same library to work with 611 // both K and L (and future) Android releases. 612 return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1; 613 #else 614 return false; 615 #endif 616 } 617 618 static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) { 619 MemoryMappingLayout memory_mapping(/*cache_enabled*/true); 620 memory_mapping.DumpListOfModules(modules); 621 } 622 623 void ListOfModules::init() { 624 clearOrInit(); 625 if (requiresProcmaps()) { 626 procmapsInit(&modules_); 627 } else { 628 DlIteratePhdrData data = {&modules_, true}; 629 dl_iterate_phdr(dl_iterate_phdr_cb, &data); 630 } 631 } 632 633 // When a custom loader is used, dl_iterate_phdr may not contain the full 634 // list of modules. Allow callers to fall back to using procmaps. 635 void ListOfModules::fallbackInit() { 636 if (!requiresProcmaps()) { 637 clearOrInit(); 638 procmapsInit(&modules_); 639 } else { 640 clear(); 641 } 642 } 643 644 // getrusage does not give us the current RSS, only the max RSS. 645 // Still, this is better than nothing if /proc/self/statm is not available 646 // for some reason, e.g. due to a sandbox. 647 static uptr GetRSSFromGetrusage() { 648 struct rusage usage; 649 if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox. 650 return 0; 651 return usage.ru_maxrss << 10; // ru_maxrss is in Kb. 652 } 653 654 uptr GetRSS() { 655 if (!common_flags()->can_use_proc_maps_statm) 656 return GetRSSFromGetrusage(); 657 fd_t fd = OpenFile("/proc/self/statm", RdOnly); 658 if (fd == kInvalidFd) 659 return GetRSSFromGetrusage(); 660 char buf[64]; 661 uptr len = internal_read(fd, buf, sizeof(buf) - 1); 662 internal_close(fd); 663 if ((sptr)len <= 0) 664 return 0; 665 buf[len] = 0; 666 // The format of the file is: 667 // 1084 89 69 11 0 79 0 668 // We need the second number which is RSS in pages. 669 char *pos = buf; 670 // Skip the first number. 671 while (*pos >= '0' && *pos <= '9') 672 pos++; 673 // Skip whitespaces. 674 while (!(*pos >= '0' && *pos <= '9') && *pos != 0) 675 pos++; 676 // Read the number. 677 uptr rss = 0; 678 while (*pos >= '0' && *pos <= '9') 679 rss = rss * 10 + *pos++ - '0'; 680 return rss * GetPageSizeCached(); 681 } 682 683 // sysconf(_SC_NPROCESSORS_{CONF,ONLN}) cannot be used on most platforms as 684 // they allocate memory. 685 u32 GetNumberOfCPUs() { 686 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD 687 u32 ncpu; 688 int req[2]; 689 uptr len = sizeof(ncpu); 690 req[0] = CTL_HW; 691 req[1] = HW_NCPU; 692 CHECK_EQ(internal_sysctl(req, 2, &ncpu, &len, NULL, 0), 0); 693 return ncpu; 694 #elif SANITIZER_ANDROID && !defined(CPU_COUNT) && !defined(__aarch64__) 695 // Fall back to /sys/devices/system/cpu on Android when cpu_set_t doesn't 696 // exist in sched.h. That is the case for toolchains generated with older 697 // NDKs. 698 // This code doesn't work on AArch64 because internal_getdents makes use of 699 // the 64bit getdents syscall, but cpu_set_t seems to always exist on AArch64. 700 uptr fd = internal_open("/sys/devices/system/cpu", O_RDONLY | O_DIRECTORY); 701 if (internal_iserror(fd)) 702 return 0; 703 InternalMmapVector<u8> buffer(4096); 704 uptr bytes_read = buffer.size(); 705 uptr n_cpus = 0; 706 u8 *d_type; 707 struct linux_dirent *entry = (struct linux_dirent *)&buffer[bytes_read]; 708 while (true) { 709 if ((u8 *)entry >= &buffer[bytes_read]) { 710 bytes_read = internal_getdents(fd, (struct linux_dirent *)buffer.data(), 711 buffer.size()); 712 if (internal_iserror(bytes_read) || !bytes_read) 713 break; 714 entry = (struct linux_dirent *)buffer.data(); 715 } 716 d_type = (u8 *)entry + entry->d_reclen - 1; 717 if (d_type >= &buffer[bytes_read] || 718 (u8 *)&entry->d_name[3] >= &buffer[bytes_read]) 719 break; 720 if (entry->d_ino != 0 && *d_type == DT_DIR) { 721 if (entry->d_name[0] == 'c' && entry->d_name[1] == 'p' && 722 entry->d_name[2] == 'u' && 723 entry->d_name[3] >= '0' && entry->d_name[3] <= '9') 724 n_cpus++; 725 } 726 entry = (struct linux_dirent *)(((u8 *)entry) + entry->d_reclen); 727 } 728 internal_close(fd); 729 return n_cpus; 730 #elif SANITIZER_SOLARIS 731 return sysconf(_SC_NPROCESSORS_ONLN); 732 #else 733 cpu_set_t CPUs; 734 CHECK_EQ(sched_getaffinity(0, sizeof(cpu_set_t), &CPUs), 0); 735 return CPU_COUNT(&CPUs); 736 #endif 737 } 738 739 #if SANITIZER_LINUX 740 741 #if SANITIZER_ANDROID 742 static atomic_uint8_t android_log_initialized; 743 744 void AndroidLogInit() { 745 openlog(GetProcessName(), 0, LOG_USER); 746 atomic_store(&android_log_initialized, 1, memory_order_release); 747 } 748 749 static bool ShouldLogAfterPrintf() { 750 return atomic_load(&android_log_initialized, memory_order_acquire); 751 } 752 753 extern "C" SANITIZER_WEAK_ATTRIBUTE 754 int async_safe_write_log(int pri, const char* tag, const char* msg); 755 extern "C" SANITIZER_WEAK_ATTRIBUTE 756 int __android_log_write(int prio, const char* tag, const char* msg); 757 758 // ANDROID_LOG_INFO is 4, but can't be resolved at runtime. 759 #define SANITIZER_ANDROID_LOG_INFO 4 760 761 // async_safe_write_log is a new public version of __libc_write_log that is 762 // used behind syslog. It is preferable to syslog as it will not do any dynamic 763 // memory allocation or formatting. 764 // If the function is not available, syslog is preferred for L+ (it was broken 765 // pre-L) as __android_log_write triggers a racey behavior with the strncpy 766 // interceptor. Fallback to __android_log_write pre-L. 767 void WriteOneLineToSyslog(const char *s) { 768 if (&async_safe_write_log) { 769 async_safe_write_log(SANITIZER_ANDROID_LOG_INFO, GetProcessName(), s); 770 } else if (AndroidGetApiLevel() > ANDROID_KITKAT) { 771 syslog(LOG_INFO, "%s", s); 772 } else { 773 CHECK(&__android_log_write); 774 __android_log_write(SANITIZER_ANDROID_LOG_INFO, nullptr, s); 775 } 776 } 777 778 extern "C" SANITIZER_WEAK_ATTRIBUTE 779 void android_set_abort_message(const char *); 780 781 void SetAbortMessage(const char *str) { 782 if (&android_set_abort_message) 783 android_set_abort_message(str); 784 } 785 #else 786 void AndroidLogInit() {} 787 788 static bool ShouldLogAfterPrintf() { return true; } 789 790 void WriteOneLineToSyslog(const char *s) { syslog(LOG_INFO, "%s", s); } 791 792 void SetAbortMessage(const char *str) {} 793 #endif // SANITIZER_ANDROID 794 795 void LogMessageOnPrintf(const char *str) { 796 if (common_flags()->log_to_syslog && ShouldLogAfterPrintf()) 797 WriteToSyslog(str); 798 } 799 800 #endif // SANITIZER_LINUX 801 802 #if SANITIZER_LINUX && !SANITIZER_GO 803 // glibc crashes when using clock_gettime from a preinit_array function as the 804 // vDSO function pointers haven't been initialized yet. __progname is 805 // initialized after the vDSO function pointers, so if it exists, is not null 806 // and is not empty, we can use clock_gettime. 807 extern "C" SANITIZER_WEAK_ATTRIBUTE char *__progname; 808 inline bool CanUseVDSO() { 809 // Bionic is safe, it checks for the vDSO function pointers to be initialized. 810 if (SANITIZER_ANDROID) 811 return true; 812 if (&__progname && __progname && *__progname) 813 return true; 814 return false; 815 } 816 817 // MonotonicNanoTime is a timing function that can leverage the vDSO by calling 818 // clock_gettime. real_clock_gettime only exists if clock_gettime is 819 // intercepted, so define it weakly and use it if available. 820 extern "C" SANITIZER_WEAK_ATTRIBUTE 821 int real_clock_gettime(u32 clk_id, void *tp); 822 u64 MonotonicNanoTime() { 823 timespec ts; 824 if (CanUseVDSO()) { 825 if (&real_clock_gettime) 826 real_clock_gettime(CLOCK_MONOTONIC, &ts); 827 else 828 clock_gettime(CLOCK_MONOTONIC, &ts); 829 } else { 830 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 831 } 832 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 833 } 834 #else 835 // Non-Linux & Go always use the syscall. 836 u64 MonotonicNanoTime() { 837 timespec ts; 838 internal_clock_gettime(CLOCK_MONOTONIC, &ts); 839 return (u64)ts.tv_sec * (1000ULL * 1000 * 1000) + ts.tv_nsec; 840 } 841 #endif // SANITIZER_LINUX && !SANITIZER_GO 842 843 #if !SANITIZER_OPENBSD 844 void ReExec() { 845 const char *pathname = "/proc/self/exe"; 846 847 #if SANITIZER_NETBSD 848 static const int name[] = { 849 CTL_KERN, 850 KERN_PROC_ARGS, 851 -1, 852 KERN_PROC_PATHNAME, 853 }; 854 char path[400]; 855 uptr len; 856 857 len = sizeof(path); 858 if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1) 859 pathname = path; 860 #elif SANITIZER_SOLARIS 861 pathname = getexecname(); 862 CHECK_NE(pathname, NULL); 863 #elif SANITIZER_USE_GETAUXVAL 864 // Calling execve with /proc/self/exe sets that as $EXEC_ORIGIN. Binaries that 865 // rely on that will fail to load shared libraries. Query AT_EXECFN instead. 866 pathname = reinterpret_cast<const char *>(getauxval(AT_EXECFN)); 867 #endif 868 869 uptr rv = internal_execve(pathname, GetArgv(), GetEnviron()); 870 int rverrno; 871 CHECK_EQ(internal_iserror(rv, &rverrno), true); 872 Printf("execve failed, errno %d\n", rverrno); 873 Die(); 874 } 875 #endif // !SANITIZER_OPENBSD 876 877 void UnmapFromTo(uptr from, uptr to) { 878 if (to == from) 879 return; 880 CHECK(to >= from); 881 uptr res = internal_munmap(reinterpret_cast<void *>(from), to - from); 882 if (UNLIKELY(internal_iserror(res))) { 883 Report("ERROR: %s failed to unmap 0x%zx (%zd) bytes at address %p\n", 884 SanitizerToolName, to - from, to - from, (void *)from); 885 CHECK("unable to unmap" && 0); 886 } 887 } 888 889 uptr MapDynamicShadow(uptr shadow_size_bytes, uptr shadow_scale, 890 uptr min_shadow_base_alignment, 891 UNUSED uptr &high_mem_end) { 892 const uptr granularity = GetMmapGranularity(); 893 const uptr alignment = 894 Max<uptr>(granularity << shadow_scale, 1ULL << min_shadow_base_alignment); 895 const uptr left_padding = 896 Max<uptr>(granularity, 1ULL << min_shadow_base_alignment); 897 898 const uptr shadow_size = RoundUpTo(shadow_size_bytes, granularity); 899 const uptr map_size = shadow_size + left_padding + alignment; 900 901 const uptr map_start = (uptr)MmapNoAccess(map_size); 902 CHECK_NE(map_start, ~(uptr)0); 903 904 const uptr shadow_start = RoundUpTo(map_start + left_padding, alignment); 905 906 UnmapFromTo(map_start, shadow_start - left_padding); 907 UnmapFromTo(shadow_start + shadow_size, map_start + map_size); 908 909 return shadow_start; 910 } 911 912 } // namespace __sanitizer 913 914 #endif 915