1 //===-- tsan_platform_linux.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 a part of ThreadSanitizer (TSan), a race detector. 10 // 11 // Linux- and BSD-specific code. 12 //===----------------------------------------------------------------------===// 13 14 #include "sanitizer_common/sanitizer_platform.h" 15 #if SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD 16 17 #include "sanitizer_common/sanitizer_common.h" 18 #include "sanitizer_common/sanitizer_libc.h" 19 #include "sanitizer_common/sanitizer_linux.h" 20 #include "sanitizer_common/sanitizer_platform_limits_netbsd.h" 21 #include "sanitizer_common/sanitizer_platform_limits_posix.h" 22 #include "sanitizer_common/sanitizer_posix.h" 23 #include "sanitizer_common/sanitizer_procmaps.h" 24 #include "sanitizer_common/sanitizer_stackdepot.h" 25 #include "sanitizer_common/sanitizer_stoptheworld.h" 26 #include "tsan_flags.h" 27 #include "tsan_platform.h" 28 #include "tsan_rtl.h" 29 30 #include <fcntl.h> 31 #include <pthread.h> 32 #include <signal.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <string.h> 36 #include <stdarg.h> 37 #include <sys/mman.h> 38 #if SANITIZER_LINUX 39 #include <sys/personality.h> 40 #include <setjmp.h> 41 #endif 42 #include <sys/syscall.h> 43 #include <sys/socket.h> 44 #include <sys/time.h> 45 #include <sys/types.h> 46 #include <sys/resource.h> 47 #include <sys/stat.h> 48 #include <unistd.h> 49 #include <sched.h> 50 #include <dlfcn.h> 51 #if SANITIZER_LINUX 52 #define __need_res_state 53 #include <resolv.h> 54 #endif 55 56 #ifdef sa_handler 57 # undef sa_handler 58 #endif 59 60 #ifdef sa_sigaction 61 # undef sa_sigaction 62 #endif 63 64 #if SANITIZER_FREEBSD 65 extern "C" void *__libc_stack_end; 66 void *__libc_stack_end = 0; 67 #endif 68 69 #if SANITIZER_LINUX && (defined(__aarch64__) || defined(__loongarch_lp64)) && \ 70 !SANITIZER_GO 71 # define INIT_LONGJMP_XOR_KEY 1 72 #else 73 # define INIT_LONGJMP_XOR_KEY 0 74 #endif 75 76 #if INIT_LONGJMP_XOR_KEY 77 #include "interception/interception.h" 78 // Must be declared outside of other namespaces. 79 DECLARE_REAL(int, _setjmp, void *env) 80 #endif 81 82 namespace __tsan { 83 84 #if INIT_LONGJMP_XOR_KEY 85 static void InitializeLongjmpXorKey(); 86 static uptr longjmp_xor_key; 87 #endif 88 89 // Runtime detected VMA size. 90 uptr vmaSize; 91 92 enum { 93 MemTotal, 94 MemShadow, 95 MemMeta, 96 MemFile, 97 MemMmap, 98 MemHeap, 99 MemOther, 100 MemCount, 101 }; 102 103 void FillProfileCallback(uptr p, uptr rss, bool file, uptr *mem) { 104 mem[MemTotal] += rss; 105 if (p >= ShadowBeg() && p < ShadowEnd()) 106 mem[MemShadow] += rss; 107 else if (p >= MetaShadowBeg() && p < MetaShadowEnd()) 108 mem[MemMeta] += rss; 109 else if ((p >= LoAppMemBeg() && p < LoAppMemEnd()) || 110 (p >= MidAppMemBeg() && p < MidAppMemEnd()) || 111 (p >= HiAppMemBeg() && p < HiAppMemEnd())) 112 mem[file ? MemFile : MemMmap] += rss; 113 else if (p >= HeapMemBeg() && p < HeapMemEnd()) 114 mem[MemHeap] += rss; 115 else 116 mem[MemOther] += rss; 117 } 118 119 void WriteMemoryProfile(char *buf, uptr buf_size, u64 uptime_ns) { 120 uptr mem[MemCount]; 121 internal_memset(mem, 0, sizeof(mem)); 122 GetMemoryProfile(FillProfileCallback, mem); 123 auto meta = ctx->metamap.GetMemoryStats(); 124 StackDepotStats stacks = StackDepotGetStats(); 125 uptr nthread, nlive; 126 ctx->thread_registry.GetNumberOfThreads(&nthread, &nlive); 127 uptr trace_mem; 128 { 129 Lock l(&ctx->slot_mtx); 130 trace_mem = ctx->trace_part_total_allocated * sizeof(TracePart); 131 } 132 uptr internal_stats[AllocatorStatCount]; 133 internal_allocator()->GetStats(internal_stats); 134 // All these are allocated from the common mmap region. 135 mem[MemMmap] -= meta.mem_block + meta.sync_obj + trace_mem + 136 stacks.allocated + internal_stats[AllocatorStatMapped]; 137 if (s64(mem[MemMmap]) < 0) 138 mem[MemMmap] = 0; 139 internal_snprintf( 140 buf, buf_size, 141 "==%zu== %llus [%zu]: RSS %zd MB: shadow:%zd meta:%zd file:%zd" 142 " mmap:%zd heap:%zd other:%zd intalloc:%zd memblocks:%zd syncobj:%zu" 143 " trace:%zu stacks=%zd threads=%zu/%zu\n", 144 internal_getpid(), uptime_ns / (1000 * 1000 * 1000), ctx->global_epoch, 145 mem[MemTotal] >> 20, mem[MemShadow] >> 20, mem[MemMeta] >> 20, 146 mem[MemFile] >> 20, mem[MemMmap] >> 20, mem[MemHeap] >> 20, 147 mem[MemOther] >> 20, internal_stats[AllocatorStatMapped] >> 20, 148 meta.mem_block >> 20, meta.sync_obj >> 20, trace_mem >> 20, 149 stacks.allocated >> 20, nlive, nthread); 150 } 151 152 #if !SANITIZER_GO 153 // Mark shadow for .rodata sections with the special Shadow::kRodata marker. 154 // Accesses to .rodata can't race, so this saves time, memory and trace space. 155 static void MapRodata() { 156 // First create temp file. 157 const char *tmpdir = GetEnv("TMPDIR"); 158 if (tmpdir == 0) 159 tmpdir = GetEnv("TEST_TMPDIR"); 160 #ifdef P_tmpdir 161 if (tmpdir == 0) 162 tmpdir = P_tmpdir; 163 #endif 164 if (tmpdir == 0) 165 return; 166 char name[256]; 167 internal_snprintf(name, sizeof(name), "%s/tsan.rodata.%d", 168 tmpdir, (int)internal_getpid()); 169 uptr openrv = internal_open(name, O_RDWR | O_CREAT | O_EXCL, 0600); 170 if (internal_iserror(openrv)) 171 return; 172 internal_unlink(name); // Unlink it now, so that we can reuse the buffer. 173 fd_t fd = openrv; 174 // Fill the file with Shadow::kRodata. 175 const uptr kMarkerSize = 512 * 1024 / sizeof(RawShadow); 176 InternalMmapVector<RawShadow> marker(kMarkerSize); 177 // volatile to prevent insertion of memset 178 for (volatile RawShadow *p = marker.data(); p < marker.data() + kMarkerSize; 179 p++) 180 *p = Shadow::kRodata; 181 internal_write(fd, marker.data(), marker.size() * sizeof(RawShadow)); 182 // Map the file into memory. 183 uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE, 184 MAP_PRIVATE | MAP_ANONYMOUS, fd, 0); 185 if (internal_iserror(page)) { 186 internal_close(fd); 187 return; 188 } 189 // Map the file into shadow of .rodata sections. 190 MemoryMappingLayout proc_maps(/*cache_enabled*/true); 191 // Reusing the buffer 'name'. 192 MemoryMappedSegment segment(name, ARRAY_SIZE(name)); 193 while (proc_maps.Next(&segment)) { 194 if (segment.filename[0] != 0 && segment.filename[0] != '[' && 195 segment.IsReadable() && segment.IsExecutable() && 196 !segment.IsWritable() && IsAppMem(segment.start)) { 197 // Assume it's .rodata 198 char *shadow_start = (char *)MemToShadow(segment.start); 199 char *shadow_end = (char *)MemToShadow(segment.end); 200 for (char *p = shadow_start; p < shadow_end; 201 p += marker.size() * sizeof(RawShadow)) { 202 internal_mmap( 203 p, Min<uptr>(marker.size() * sizeof(RawShadow), shadow_end - p), 204 PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0); 205 } 206 } 207 } 208 internal_close(fd); 209 } 210 211 void InitializeShadowMemoryPlatform() { 212 MapRodata(); 213 } 214 215 #endif // #if !SANITIZER_GO 216 217 void InitializePlatformEarly() { 218 vmaSize = 219 (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1); 220 #if defined(__aarch64__) 221 # if !SANITIZER_GO 222 if (vmaSize != 39 && vmaSize != 42 && vmaSize != 48) { 223 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n"); 224 Printf("FATAL: Found %zd - Supported 39, 42 and 48\n", vmaSize); 225 Die(); 226 } 227 #else 228 if (vmaSize != 48) { 229 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n"); 230 Printf("FATAL: Found %zd - Supported 48\n", vmaSize); 231 Die(); 232 } 233 #endif 234 #elif SANITIZER_LOONGARCH64 235 # if !SANITIZER_GO 236 if (vmaSize != 47) { 237 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n"); 238 Printf("FATAL: Found %zd - Supported 47\n", vmaSize); 239 Die(); 240 } 241 # endif 242 #elif defined(__powerpc64__) 243 # if !SANITIZER_GO 244 if (vmaSize != 44 && vmaSize != 46 && vmaSize != 47) { 245 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n"); 246 Printf("FATAL: Found %zd - Supported 44, 46, and 47\n", vmaSize); 247 Die(); 248 } 249 # else 250 if (vmaSize != 46 && vmaSize != 47) { 251 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n"); 252 Printf("FATAL: Found %zd - Supported 46, and 47\n", vmaSize); 253 Die(); 254 } 255 # endif 256 #elif defined(__mips64) 257 # if !SANITIZER_GO 258 if (vmaSize != 40) { 259 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n"); 260 Printf("FATAL: Found %zd - Supported 40\n", vmaSize); 261 Die(); 262 } 263 # else 264 if (vmaSize != 47) { 265 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n"); 266 Printf("FATAL: Found %zd - Supported 47\n", vmaSize); 267 Die(); 268 } 269 # endif 270 #endif 271 } 272 273 void InitializePlatform() { 274 DisableCoreDumperIfNecessary(); 275 276 // Go maps shadow memory lazily and works fine with limited address space. 277 // Unlimited stack is not a problem as well, because the executable 278 // is not compiled with -pie. 279 #if !SANITIZER_GO 280 { 281 bool reexec = false; 282 // TSan doesn't play well with unlimited stack size (as stack 283 // overlaps with shadow memory). If we detect unlimited stack size, 284 // we re-exec the program with limited stack size as a best effort. 285 if (StackSizeIsUnlimited()) { 286 const uptr kMaxStackSize = 32 * 1024 * 1024; 287 VReport(1, "Program is run with unlimited stack size, which wouldn't " 288 "work with ThreadSanitizer.\n" 289 "Re-execing with stack size limited to %zd bytes.\n", 290 kMaxStackSize); 291 SetStackSizeLimitInBytes(kMaxStackSize); 292 reexec = true; 293 } 294 295 if (!AddressSpaceIsUnlimited()) { 296 Report("WARNING: Program is run with limited virtual address space," 297 " which wouldn't work with ThreadSanitizer.\n"); 298 Report("Re-execing with unlimited virtual address space.\n"); 299 SetAddressSpaceUnlimited(); 300 reexec = true; 301 } 302 #if SANITIZER_ANDROID && (defined(__aarch64__) || defined(__x86_64__)) 303 // After patch "arm64: mm: support ARCH_MMAP_RND_BITS." is introduced in 304 // linux kernel, the random gap between stack and mapped area is increased 305 // from 128M to 36G on 39-bit aarch64. As it is almost impossible to cover 306 // this big range, we should disable randomized virtual space on aarch64. 307 // ASLR personality check. 308 int old_personality = personality(0xffffffff); 309 if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) { 310 VReport(1, "WARNING: Program is run with randomized virtual address " 311 "space, which wouldn't work with ThreadSanitizer.\n" 312 "Re-execing with fixed virtual address space.\n"); 313 CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1); 314 reexec = true; 315 } 316 317 #endif 318 #if SANITIZER_LINUX && (defined(__aarch64__) || defined(__loongarch_lp64)) 319 // Initialize the xor key used in {sig}{set,long}jump. 320 InitializeLongjmpXorKey(); 321 #endif 322 if (reexec) 323 ReExec(); 324 } 325 326 CheckAndProtect(); 327 InitTlsSize(); 328 #endif // !SANITIZER_GO 329 } 330 331 #if !SANITIZER_GO 332 // Extract file descriptors passed to glibc internal __res_iclose function. 333 // This is required to properly "close" the fds, because we do not see internal 334 // closes within glibc. The code is a pure hack. 335 int ExtractResolvFDs(void *state, int *fds, int nfd) { 336 #if SANITIZER_LINUX && !SANITIZER_ANDROID 337 int cnt = 0; 338 struct __res_state *statp = (struct __res_state*)state; 339 for (int i = 0; i < MAXNS && cnt < nfd; i++) { 340 if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1) 341 fds[cnt++] = statp->_u._ext.nssocks[i]; 342 } 343 return cnt; 344 #else 345 return 0; 346 #endif 347 } 348 349 // Extract file descriptors passed via UNIX domain sockets. 350 // This is required to properly handle "open" of these fds. 351 // see 'man recvmsg' and 'man 3 cmsg'. 352 int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) { 353 int res = 0; 354 msghdr *msg = (msghdr*)msgp; 355 struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg); 356 for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) { 357 if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) 358 continue; 359 int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]); 360 for (int i = 0; i < n; i++) { 361 fds[res++] = ((int*)CMSG_DATA(cmsg))[i]; 362 if (res == nfd) 363 return res; 364 } 365 } 366 return res; 367 } 368 369 // Reverse operation of libc stack pointer mangling 370 static uptr UnmangleLongJmpSp(uptr mangled_sp) { 371 #if defined(__x86_64__) 372 # if SANITIZER_LINUX 373 // Reverse of: 374 // xor %fs:0x30, %rsi 375 // rol $0x11, %rsi 376 uptr sp; 377 asm("ror $0x11, %0 \n" 378 "xor %%fs:0x30, %0 \n" 379 : "=r" (sp) 380 : "0" (mangled_sp)); 381 return sp; 382 # else 383 return mangled_sp; 384 # endif 385 #elif defined(__aarch64__) 386 # if SANITIZER_LINUX 387 return mangled_sp ^ longjmp_xor_key; 388 # else 389 return mangled_sp; 390 # endif 391 #elif defined(__loongarch_lp64) 392 return mangled_sp ^ longjmp_xor_key; 393 #elif defined(__powerpc64__) 394 // Reverse of: 395 // ld r4, -28696(r13) 396 // xor r4, r3, r4 397 uptr xor_key; 398 asm("ld %0, -28696(%%r13)" : "=r" (xor_key)); 399 return mangled_sp ^ xor_key; 400 #elif defined(__mips__) 401 return mangled_sp; 402 #elif defined(__s390x__) 403 // tcbhead_t.stack_guard 404 uptr xor_key = ((uptr *)__builtin_thread_pointer())[5]; 405 return mangled_sp ^ xor_key; 406 #else 407 #error "Unknown platform" 408 #endif 409 } 410 411 #if SANITIZER_NETBSD 412 # ifdef __x86_64__ 413 # define LONG_JMP_SP_ENV_SLOT 6 414 # else 415 # error unsupported 416 # endif 417 #elif defined(__powerpc__) 418 # define LONG_JMP_SP_ENV_SLOT 0 419 #elif SANITIZER_FREEBSD 420 # ifdef __aarch64__ 421 # define LONG_JMP_SP_ENV_SLOT 1 422 # else 423 # define LONG_JMP_SP_ENV_SLOT 2 424 # endif 425 #elif SANITIZER_LINUX 426 # ifdef __aarch64__ 427 # define LONG_JMP_SP_ENV_SLOT 13 428 # elif defined(__loongarch__) 429 # define LONG_JMP_SP_ENV_SLOT 1 430 # elif defined(__mips64) 431 # define LONG_JMP_SP_ENV_SLOT 1 432 # elif defined(__s390x__) 433 # define LONG_JMP_SP_ENV_SLOT 9 434 # else 435 # define LONG_JMP_SP_ENV_SLOT 6 436 # endif 437 #endif 438 439 uptr ExtractLongJmpSp(uptr *env) { 440 uptr mangled_sp = env[LONG_JMP_SP_ENV_SLOT]; 441 return UnmangleLongJmpSp(mangled_sp); 442 } 443 444 #if INIT_LONGJMP_XOR_KEY 445 // GLIBC mangles the function pointers in jmp_buf (used in {set,long}*jmp 446 // functions) by XORing them with a random key. For AArch64 it is a global 447 // variable rather than a TCB one (as for x86_64/powerpc). We obtain the key by 448 // issuing a setjmp and XORing the SP pointer values to derive the key. 449 static void InitializeLongjmpXorKey() { 450 // 1. Call REAL(setjmp), which stores the mangled SP in env. 451 jmp_buf env; 452 REAL(_setjmp)(env); 453 454 // 2. Retrieve vanilla/mangled SP. 455 uptr sp; 456 #ifdef __loongarch__ 457 asm("move %0, $sp" : "=r" (sp)); 458 #else 459 asm("mov %0, sp" : "=r" (sp)); 460 #endif 461 uptr mangled_sp = ((uptr *)&env)[LONG_JMP_SP_ENV_SLOT]; 462 463 // 3. xor SPs to obtain key. 464 longjmp_xor_key = mangled_sp ^ sp; 465 } 466 #endif 467 468 extern "C" void __tsan_tls_initialization() {} 469 470 void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) { 471 // Check that the thr object is in tls; 472 const uptr thr_beg = (uptr)thr; 473 const uptr thr_end = (uptr)thr + sizeof(*thr); 474 CHECK_GE(thr_beg, tls_addr); 475 CHECK_LE(thr_beg, tls_addr + tls_size); 476 CHECK_GE(thr_end, tls_addr); 477 CHECK_LE(thr_end, tls_addr + tls_size); 478 // Since the thr object is huge, skip it. 479 const uptr pc = StackTrace::GetNextInstructionPc( 480 reinterpret_cast<uptr>(__tsan_tls_initialization)); 481 MemoryRangeImitateWrite(thr, pc, tls_addr, thr_beg - tls_addr); 482 MemoryRangeImitateWrite(thr, pc, thr_end, tls_addr + tls_size - thr_end); 483 } 484 485 // Note: this function runs with async signals enabled, 486 // so it must not touch any tsan state. 487 int call_pthread_cancel_with_cleanup(int (*fn)(void *arg), 488 void (*cleanup)(void *arg), void *arg) { 489 // pthread_cleanup_push/pop are hardcore macros mess. 490 // We can't intercept nor call them w/o including pthread.h. 491 int res; 492 pthread_cleanup_push(cleanup, arg); 493 res = fn(arg); 494 pthread_cleanup_pop(0); 495 return res; 496 } 497 #endif // !SANITIZER_GO 498 499 #if !SANITIZER_GO 500 void ReplaceSystemMalloc() { } 501 #endif 502 503 #if !SANITIZER_GO 504 #if SANITIZER_ANDROID 505 // On Android, one thread can call intercepted functions after 506 // DestroyThreadState(), so add a fake thread state for "dead" threads. 507 static ThreadState *dead_thread_state = nullptr; 508 509 ThreadState *cur_thread() { 510 ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr()); 511 if (thr == nullptr) { 512 __sanitizer_sigset_t emptyset; 513 internal_sigfillset(&emptyset); 514 __sanitizer_sigset_t oldset; 515 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset)); 516 thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr()); 517 if (thr == nullptr) { 518 thr = reinterpret_cast<ThreadState*>(MmapOrDie(sizeof(ThreadState), 519 "ThreadState")); 520 *get_android_tls_ptr() = reinterpret_cast<uptr>(thr); 521 if (dead_thread_state == nullptr) { 522 dead_thread_state = reinterpret_cast<ThreadState*>( 523 MmapOrDie(sizeof(ThreadState), "ThreadState")); 524 dead_thread_state->fast_state.SetIgnoreBit(); 525 dead_thread_state->ignore_interceptors = 1; 526 dead_thread_state->is_dead = true; 527 *const_cast<u32*>(&dead_thread_state->tid) = -1; 528 CHECK_EQ(0, internal_mprotect(dead_thread_state, sizeof(ThreadState), 529 PROT_READ)); 530 } 531 } 532 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr)); 533 } 534 return thr; 535 } 536 537 void set_cur_thread(ThreadState *thr) { 538 *get_android_tls_ptr() = reinterpret_cast<uptr>(thr); 539 } 540 541 void cur_thread_finalize() { 542 __sanitizer_sigset_t emptyset; 543 internal_sigfillset(&emptyset); 544 __sanitizer_sigset_t oldset; 545 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset)); 546 ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr()); 547 if (thr != dead_thread_state) { 548 *get_android_tls_ptr() = reinterpret_cast<uptr>(dead_thread_state); 549 UnmapOrDie(thr, sizeof(ThreadState)); 550 } 551 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr)); 552 } 553 #endif // SANITIZER_ANDROID 554 #endif // if !SANITIZER_GO 555 556 } // namespace __tsan 557 558 #endif // SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD 559