tsan_platform_linux.cpp revision 360784
1251607Sdim//===-- tsan_platform_linux.cpp -------------------------------------------===// 2251607Sdim// 3251607Sdim// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4251607Sdim// See https://llvm.org/LICENSE.txt for license information. 5251607Sdim// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6251607Sdim// 7251607Sdim//===----------------------------------------------------------------------===// 8251607Sdim// 9251607Sdim// This file is a part of ThreadSanitizer (TSan), a race detector. 10251607Sdim// 11251607Sdim// Linux- and FreeBSD-specific code. 12251607Sdim//===----------------------------------------------------------------------===// 13251607Sdim 14251607Sdim 15251607Sdim#include "sanitizer_common/sanitizer_platform.h" 16251607Sdim#if SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD 17251607Sdim 18251607Sdim#include "sanitizer_common/sanitizer_common.h" 19251607Sdim#include "sanitizer_common/sanitizer_libc.h" 20251607Sdim#include "sanitizer_common/sanitizer_linux.h" 21251607Sdim#include "sanitizer_common/sanitizer_platform_limits_netbsd.h" 22251607Sdim#include "sanitizer_common/sanitizer_platform_limits_posix.h" 23251607Sdim#include "sanitizer_common/sanitizer_posix.h" 24#include "sanitizer_common/sanitizer_procmaps.h" 25#include "sanitizer_common/sanitizer_stoptheworld.h" 26#include "sanitizer_common/sanitizer_stackdepot.h" 27#include "tsan_platform.h" 28#include "tsan_rtl.h" 29#include "tsan_flags.h" 30 31#include <fcntl.h> 32#include <pthread.h> 33#include <signal.h> 34#include <stdio.h> 35#include <stdlib.h> 36#include <string.h> 37#include <stdarg.h> 38#include <sys/mman.h> 39#if SANITIZER_LINUX 40#include <sys/personality.h> 41#include <setjmp.h> 42#endif 43#include <sys/syscall.h> 44#include <sys/socket.h> 45#include <sys/time.h> 46#include <sys/types.h> 47#include <sys/resource.h> 48#include <sys/stat.h> 49#include <unistd.h> 50#include <sched.h> 51#include <dlfcn.h> 52#if SANITIZER_LINUX 53#define __need_res_state 54#include <resolv.h> 55#endif 56 57#ifdef sa_handler 58# undef sa_handler 59#endif 60 61#ifdef sa_sigaction 62# undef sa_sigaction 63#endif 64 65#if SANITIZER_FREEBSD 66extern "C" void *__libc_stack_end; 67void *__libc_stack_end = 0; 68#endif 69 70#if SANITIZER_LINUX && defined(__aarch64__) && !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. 79DECLARE_REAL(int, _setjmp, void *env) 80#endif 81 82namespace __tsan { 83 84#if INIT_LONGJMP_XOR_KEY 85static void InitializeLongjmpXorKey(); 86static uptr longjmp_xor_key; 87#endif 88 89#ifdef TSAN_RUNTIME_VMA 90// Runtime detected VMA size. 91uptr vmaSize; 92#endif 93 94enum { 95 MemTotal = 0, 96 MemShadow = 1, 97 MemMeta = 2, 98 MemFile = 3, 99 MemMmap = 4, 100 MemTrace = 5, 101 MemHeap = 6, 102 MemOther = 7, 103 MemCount = 8, 104}; 105 106void FillProfileCallback(uptr p, uptr rss, bool file, 107 uptr *mem, uptr stats_size) { 108 mem[MemTotal] += rss; 109 if (p >= ShadowBeg() && p < ShadowEnd()) 110 mem[MemShadow] += rss; 111 else if (p >= MetaShadowBeg() && p < MetaShadowEnd()) 112 mem[MemMeta] += rss; 113#if !SANITIZER_GO 114 else if (p >= HeapMemBeg() && p < HeapMemEnd()) 115 mem[MemHeap] += rss; 116 else if (p >= LoAppMemBeg() && p < LoAppMemEnd()) 117 mem[file ? MemFile : MemMmap] += rss; 118 else if (p >= HiAppMemBeg() && p < HiAppMemEnd()) 119 mem[file ? MemFile : MemMmap] += rss; 120#else 121 else if (p >= AppMemBeg() && p < AppMemEnd()) 122 mem[file ? MemFile : MemMmap] += rss; 123#endif 124 else if (p >= TraceMemBeg() && p < TraceMemEnd()) 125 mem[MemTrace] += rss; 126 else 127 mem[MemOther] += rss; 128} 129 130void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) { 131 uptr mem[MemCount]; 132 internal_memset(mem, 0, sizeof(mem[0]) * MemCount); 133 __sanitizer::GetMemoryProfile(FillProfileCallback, mem, 7); 134 StackDepotStats *stacks = StackDepotGetStats(); 135 internal_snprintf(buf, buf_size, 136 "RSS %zd MB: shadow:%zd meta:%zd file:%zd mmap:%zd" 137 " trace:%zd heap:%zd other:%zd stacks=%zd[%zd] nthr=%zd/%zd\n", 138 mem[MemTotal] >> 20, mem[MemShadow] >> 20, mem[MemMeta] >> 20, 139 mem[MemFile] >> 20, mem[MemMmap] >> 20, mem[MemTrace] >> 20, 140 mem[MemHeap] >> 20, mem[MemOther] >> 20, 141 stacks->allocated >> 20, stacks->n_uniq_ids, 142 nlive, nthread); 143} 144 145#if SANITIZER_LINUX 146void FlushShadowMemoryCallback( 147 const SuspendedThreadsList &suspended_threads_list, 148 void *argument) { 149 ReleaseMemoryPagesToOS(ShadowBeg(), ShadowEnd()); 150} 151#endif 152 153void FlushShadowMemory() { 154#if SANITIZER_LINUX 155 StopTheWorld(FlushShadowMemoryCallback, 0); 156#endif 157} 158 159#if !SANITIZER_GO 160// Mark shadow for .rodata sections with the special kShadowRodata marker. 161// Accesses to .rodata can't race, so this saves time, memory and trace space. 162static void MapRodata() { 163 // First create temp file. 164 const char *tmpdir = GetEnv("TMPDIR"); 165 if (tmpdir == 0) 166 tmpdir = GetEnv("TEST_TMPDIR"); 167#ifdef P_tmpdir 168 if (tmpdir == 0) 169 tmpdir = P_tmpdir; 170#endif 171 if (tmpdir == 0) 172 return; 173 char name[256]; 174 internal_snprintf(name, sizeof(name), "%s/tsan.rodata.%d", 175 tmpdir, (int)internal_getpid()); 176 uptr openrv = internal_open(name, O_RDWR | O_CREAT | O_EXCL, 0600); 177 if (internal_iserror(openrv)) 178 return; 179 internal_unlink(name); // Unlink it now, so that we can reuse the buffer. 180 fd_t fd = openrv; 181 // Fill the file with kShadowRodata. 182 const uptr kMarkerSize = 512 * 1024 / sizeof(u64); 183 InternalMmapVector<u64> marker(kMarkerSize); 184 // volatile to prevent insertion of memset 185 for (volatile u64 *p = marker.data(); p < marker.data() + kMarkerSize; p++) 186 *p = kShadowRodata; 187 internal_write(fd, marker.data(), marker.size() * sizeof(u64)); 188 // Map the file into memory. 189 uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE, 190 MAP_PRIVATE | MAP_ANONYMOUS, fd, 0); 191 if (internal_iserror(page)) { 192 internal_close(fd); 193 return; 194 } 195 // Map the file into shadow of .rodata sections. 196 MemoryMappingLayout proc_maps(/*cache_enabled*/true); 197 // Reusing the buffer 'name'. 198 MemoryMappedSegment segment(name, ARRAY_SIZE(name)); 199 while (proc_maps.Next(&segment)) { 200 if (segment.filename[0] != 0 && segment.filename[0] != '[' && 201 segment.IsReadable() && segment.IsExecutable() && 202 !segment.IsWritable() && IsAppMem(segment.start)) { 203 // Assume it's .rodata 204 char *shadow_start = (char *)MemToShadow(segment.start); 205 char *shadow_end = (char *)MemToShadow(segment.end); 206 for (char *p = shadow_start; p < shadow_end; 207 p += marker.size() * sizeof(u64)) { 208 internal_mmap(p, Min<uptr>(marker.size() * sizeof(u64), shadow_end - p), 209 PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0); 210 } 211 } 212 } 213 internal_close(fd); 214} 215 216void InitializeShadowMemoryPlatform() { 217 MapRodata(); 218} 219 220#endif // #if !SANITIZER_GO 221 222void InitializePlatformEarly() { 223#ifdef TSAN_RUNTIME_VMA 224 vmaSize = 225 (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1); 226#if defined(__aarch64__) 227# if !SANITIZER_GO 228 if (vmaSize != 39 && vmaSize != 42 && vmaSize != 48) { 229 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n"); 230 Printf("FATAL: Found %zd - Supported 39, 42 and 48\n", vmaSize); 231 Die(); 232 } 233#else 234 if (vmaSize != 48) { 235 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n"); 236 Printf("FATAL: Found %zd - Supported 48\n", vmaSize); 237 Die(); 238 } 239#endif 240#elif defined(__powerpc64__) 241# if !SANITIZER_GO 242 if (vmaSize != 44 && vmaSize != 46 && vmaSize != 47) { 243 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n"); 244 Printf("FATAL: Found %zd - Supported 44, 46, and 47\n", vmaSize); 245 Die(); 246 } 247# else 248 if (vmaSize != 46 && vmaSize != 47) { 249 Printf("FATAL: ThreadSanitizer: unsupported VMA range\n"); 250 Printf("FATAL: Found %zd - Supported 46, and 47\n", vmaSize); 251 Die(); 252 } 253# endif 254#endif 255#endif 256} 257 258void InitializePlatform() { 259 DisableCoreDumperIfNecessary(); 260 261 // Go maps shadow memory lazily and works fine with limited address space. 262 // Unlimited stack is not a problem as well, because the executable 263 // is not compiled with -pie. 264#if !SANITIZER_GO 265 { 266 bool reexec = false; 267 // TSan doesn't play well with unlimited stack size (as stack 268 // overlaps with shadow memory). If we detect unlimited stack size, 269 // we re-exec the program with limited stack size as a best effort. 270 if (StackSizeIsUnlimited()) { 271 const uptr kMaxStackSize = 32 * 1024 * 1024; 272 VReport(1, "Program is run with unlimited stack size, which wouldn't " 273 "work with ThreadSanitizer.\n" 274 "Re-execing with stack size limited to %zd bytes.\n", 275 kMaxStackSize); 276 SetStackSizeLimitInBytes(kMaxStackSize); 277 reexec = true; 278 } 279 280 if (!AddressSpaceIsUnlimited()) { 281 Report("WARNING: Program is run with limited virtual address space," 282 " which wouldn't work with ThreadSanitizer.\n"); 283 Report("Re-execing with unlimited virtual address space.\n"); 284 SetAddressSpaceUnlimited(); 285 reexec = true; 286 } 287#if SANITIZER_LINUX && defined(__aarch64__) 288 // After patch "arm64: mm: support ARCH_MMAP_RND_BITS." is introduced in 289 // linux kernel, the random gap between stack and mapped area is increased 290 // from 128M to 36G on 39-bit aarch64. As it is almost impossible to cover 291 // this big range, we should disable randomized virtual space on aarch64. 292 int old_personality = personality(0xffffffff); 293 if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) { 294 VReport(1, "WARNING: Program is run with randomized virtual address " 295 "space, which wouldn't work with ThreadSanitizer.\n" 296 "Re-execing with fixed virtual address space.\n"); 297 CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1); 298 reexec = true; 299 } 300 // Initialize the xor key used in {sig}{set,long}jump. 301 InitializeLongjmpXorKey(); 302#endif 303 if (reexec) 304 ReExec(); 305 } 306 307 CheckAndProtect(); 308 InitTlsSize(); 309#endif // !SANITIZER_GO 310} 311 312#if !SANITIZER_GO 313// Extract file descriptors passed to glibc internal __res_iclose function. 314// This is required to properly "close" the fds, because we do not see internal 315// closes within glibc. The code is a pure hack. 316int ExtractResolvFDs(void *state, int *fds, int nfd) { 317#if SANITIZER_LINUX && !SANITIZER_ANDROID 318 int cnt = 0; 319 struct __res_state *statp = (struct __res_state*)state; 320 for (int i = 0; i < MAXNS && cnt < nfd; i++) { 321 if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1) 322 fds[cnt++] = statp->_u._ext.nssocks[i]; 323 } 324 return cnt; 325#else 326 return 0; 327#endif 328} 329 330// Extract file descriptors passed via UNIX domain sockets. 331// This is requried to properly handle "open" of these fds. 332// see 'man recvmsg' and 'man 3 cmsg'. 333int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) { 334 int res = 0; 335 msghdr *msg = (msghdr*)msgp; 336 struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg); 337 for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) { 338 if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) 339 continue; 340 int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]); 341 for (int i = 0; i < n; i++) { 342 fds[res++] = ((int*)CMSG_DATA(cmsg))[i]; 343 if (res == nfd) 344 return res; 345 } 346 } 347 return res; 348} 349 350// Reverse operation of libc stack pointer mangling 351static uptr UnmangleLongJmpSp(uptr mangled_sp) { 352#if defined(__x86_64__) 353# if SANITIZER_LINUX 354 // Reverse of: 355 // xor %fs:0x30, %rsi 356 // rol $0x11, %rsi 357 uptr sp; 358 asm("ror $0x11, %0 \n" 359 "xor %%fs:0x30, %0 \n" 360 : "=r" (sp) 361 : "0" (mangled_sp)); 362 return sp; 363# else 364 return mangled_sp; 365# endif 366#elif defined(__aarch64__) 367# if SANITIZER_LINUX 368 return mangled_sp ^ longjmp_xor_key; 369# else 370 return mangled_sp; 371# endif 372#elif defined(__powerpc64__) 373 // Reverse of: 374 // ld r4, -28696(r13) 375 // xor r4, r3, r4 376 uptr xor_key; 377 asm("ld %0, -28696(%%r13)" : "=r" (xor_key)); 378 return mangled_sp ^ xor_key; 379#elif defined(__mips__) 380 return mangled_sp; 381#else 382 #error "Unknown platform" 383#endif 384} 385 386#ifdef __powerpc__ 387# define LONG_JMP_SP_ENV_SLOT 0 388#elif SANITIZER_FREEBSD 389# define LONG_JMP_SP_ENV_SLOT 2 390#elif SANITIZER_NETBSD 391# define LONG_JMP_SP_ENV_SLOT 6 392#elif SANITIZER_LINUX 393# ifdef __aarch64__ 394# define LONG_JMP_SP_ENV_SLOT 13 395# elif defined(__mips64) 396# define LONG_JMP_SP_ENV_SLOT 1 397# else 398# define LONG_JMP_SP_ENV_SLOT 6 399# endif 400#endif 401 402uptr ExtractLongJmpSp(uptr *env) { 403 uptr mangled_sp = env[LONG_JMP_SP_ENV_SLOT]; 404 return UnmangleLongJmpSp(mangled_sp); 405} 406 407#if INIT_LONGJMP_XOR_KEY 408// GLIBC mangles the function pointers in jmp_buf (used in {set,long}*jmp 409// functions) by XORing them with a random key. For AArch64 it is a global 410// variable rather than a TCB one (as for x86_64/powerpc). We obtain the key by 411// issuing a setjmp and XORing the SP pointer values to derive the key. 412static void InitializeLongjmpXorKey() { 413 // 1. Call REAL(setjmp), which stores the mangled SP in env. 414 jmp_buf env; 415 REAL(_setjmp)(env); 416 417 // 2. Retrieve vanilla/mangled SP. 418 uptr sp; 419 asm("mov %0, sp" : "=r" (sp)); 420 uptr mangled_sp = ((uptr *)&env)[LONG_JMP_SP_ENV_SLOT]; 421 422 // 3. xor SPs to obtain key. 423 longjmp_xor_key = mangled_sp ^ sp; 424} 425#endif 426 427void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) { 428 // Check that the thr object is in tls; 429 const uptr thr_beg = (uptr)thr; 430 const uptr thr_end = (uptr)thr + sizeof(*thr); 431 CHECK_GE(thr_beg, tls_addr); 432 CHECK_LE(thr_beg, tls_addr + tls_size); 433 CHECK_GE(thr_end, tls_addr); 434 CHECK_LE(thr_end, tls_addr + tls_size); 435 // Since the thr object is huge, skip it. 436 MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr, thr_beg - tls_addr); 437 MemoryRangeImitateWrite(thr, /*pc=*/2, thr_end, 438 tls_addr + tls_size - thr_end); 439} 440 441// Note: this function runs with async signals enabled, 442// so it must not touch any tsan state. 443int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m, 444 void *abstime), void *c, void *m, void *abstime, 445 void(*cleanup)(void *arg), void *arg) { 446 // pthread_cleanup_push/pop are hardcore macros mess. 447 // We can't intercept nor call them w/o including pthread.h. 448 int res; 449 pthread_cleanup_push(cleanup, arg); 450 res = fn(c, m, abstime); 451 pthread_cleanup_pop(0); 452 return res; 453} 454#endif // !SANITIZER_GO 455 456#if !SANITIZER_GO 457void ReplaceSystemMalloc() { } 458#endif 459 460#if !SANITIZER_GO 461#if SANITIZER_ANDROID 462// On Android, one thread can call intercepted functions after 463// DestroyThreadState(), so add a fake thread state for "dead" threads. 464static ThreadState *dead_thread_state = nullptr; 465 466ThreadState *cur_thread() { 467 ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr()); 468 if (thr == nullptr) { 469 __sanitizer_sigset_t emptyset; 470 internal_sigfillset(&emptyset); 471 __sanitizer_sigset_t oldset; 472 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset)); 473 thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr()); 474 if (thr == nullptr) { 475 thr = reinterpret_cast<ThreadState*>(MmapOrDie(sizeof(ThreadState), 476 "ThreadState")); 477 *get_android_tls_ptr() = reinterpret_cast<uptr>(thr); 478 if (dead_thread_state == nullptr) { 479 dead_thread_state = reinterpret_cast<ThreadState*>( 480 MmapOrDie(sizeof(ThreadState), "ThreadState")); 481 dead_thread_state->fast_state.SetIgnoreBit(); 482 dead_thread_state->ignore_interceptors = 1; 483 dead_thread_state->is_dead = true; 484 *const_cast<int*>(&dead_thread_state->tid) = -1; 485 CHECK_EQ(0, internal_mprotect(dead_thread_state, sizeof(ThreadState), 486 PROT_READ)); 487 } 488 } 489 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr)); 490 } 491 return thr; 492} 493 494void set_cur_thread(ThreadState *thr) { 495 *get_android_tls_ptr() = reinterpret_cast<uptr>(thr); 496} 497 498void cur_thread_finalize() { 499 __sanitizer_sigset_t emptyset; 500 internal_sigfillset(&emptyset); 501 __sanitizer_sigset_t oldset; 502 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset)); 503 ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr()); 504 if (thr != dead_thread_state) { 505 *get_android_tls_ptr() = reinterpret_cast<uptr>(dead_thread_state); 506 UnmapOrDie(thr, sizeof(ThreadState)); 507 } 508 CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr)); 509} 510#endif // SANITIZER_ANDROID 511#endif // if !SANITIZER_GO 512 513} // namespace __tsan 514 515#endif // SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD 516