1 //===-- sanitizer_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 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_common.h" 20 #include "sanitizer_flags.h" 21 #include "sanitizer_getauxval.h" 22 #include "sanitizer_internal_defs.h" 23 #include "sanitizer_libc.h" 24 #include "sanitizer_linux.h" 25 #include "sanitizer_mutex.h" 26 #include "sanitizer_placement_new.h" 27 #include "sanitizer_procmaps.h" 28 29 #if SANITIZER_LINUX && !SANITIZER_GO 30 #include <asm/param.h> 31 #endif 32 33 // For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat' 34 // format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To 35 // access stat from asm/stat.h, without conflicting with definition in 36 // sys/stat.h, we use this trick. 37 #if defined(__mips64) 38 #include <asm/unistd.h> 39 #include <sys/types.h> 40 #define stat kernel_stat 41 #include <asm/stat.h> 42 #undef stat 43 #endif 44 45 #include <dlfcn.h> 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <link.h> 49 #include <pthread.h> 50 #include <sched.h> 51 #include <signal.h> 52 #include <sys/mman.h> 53 #include <sys/param.h> 54 #if !SANITIZER_SOLARIS 55 #include <sys/ptrace.h> 56 #endif 57 #include <sys/resource.h> 58 #include <sys/stat.h> 59 #include <sys/syscall.h> 60 #include <sys/time.h> 61 #include <sys/types.h> 62 #include <ucontext.h> 63 #include <unistd.h> 64 65 #if SANITIZER_LINUX 66 #include <sys/utsname.h> 67 #endif 68 69 #if SANITIZER_LINUX && !SANITIZER_ANDROID 70 #include <sys/personality.h> 71 #endif 72 73 #if SANITIZER_FREEBSD 74 #include <sys/exec.h> 75 #include <sys/sysctl.h> 76 #include <machine/atomic.h> 77 extern "C" { 78 // <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on 79 // FreeBSD 9.2 and 10.0. 80 #include <sys/umtx.h> 81 } 82 #include <sys/thr.h> 83 #endif // SANITIZER_FREEBSD 84 85 #if SANITIZER_NETBSD 86 #include <limits.h> // For NAME_MAX 87 #include <sys/sysctl.h> 88 #include <sys/exec.h> 89 extern struct ps_strings *__ps_strings; 90 #endif // SANITIZER_NETBSD 91 92 #if SANITIZER_SOLARIS 93 #include <stdlib.h> 94 #include <thread.h> 95 #define environ _environ 96 #endif 97 98 extern char **environ; 99 100 #if SANITIZER_LINUX 101 // <linux/time.h> 102 struct kernel_timeval { 103 long tv_sec; 104 long tv_usec; 105 }; 106 107 // <linux/futex.h> is broken on some linux distributions. 108 const int FUTEX_WAIT = 0; 109 const int FUTEX_WAKE = 1; 110 const int FUTEX_PRIVATE_FLAG = 128; 111 const int FUTEX_WAIT_PRIVATE = FUTEX_WAIT | FUTEX_PRIVATE_FLAG; 112 const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG; 113 #endif // SANITIZER_LINUX 114 115 // Are we using 32-bit or 64-bit Linux syscalls? 116 // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32 117 // but it still needs to use 64-bit syscalls. 118 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \ 119 SANITIZER_WORDSIZE == 64) 120 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1 121 #else 122 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0 123 #endif 124 125 // Note : FreeBSD had implemented both 126 // Linux apis, available from 127 // future 12.x version most likely 128 #if SANITIZER_LINUX && defined(__NR_getrandom) 129 # if !defined(GRND_NONBLOCK) 130 # define GRND_NONBLOCK 1 131 # endif 132 # define SANITIZER_USE_GETRANDOM 1 133 #else 134 # define SANITIZER_USE_GETRANDOM 0 135 #endif // SANITIZER_LINUX && defined(__NR_getrandom) 136 137 #if SANITIZER_FREEBSD && __FreeBSD_version >= 1200000 138 # define SANITIZER_USE_GETENTROPY 1 139 #else 140 # define SANITIZER_USE_GETENTROPY 0 141 #endif 142 143 namespace __sanitizer { 144 145 #if SANITIZER_LINUX && defined(__x86_64__) 146 #include "sanitizer_syscall_linux_x86_64.inc" 147 #elif SANITIZER_LINUX && SANITIZER_RISCV64 148 #include "sanitizer_syscall_linux_riscv64.inc" 149 #elif SANITIZER_LINUX && defined(__aarch64__) 150 #include "sanitizer_syscall_linux_aarch64.inc" 151 #elif SANITIZER_LINUX && defined(__arm__) 152 #include "sanitizer_syscall_linux_arm.inc" 153 #else 154 #include "sanitizer_syscall_generic.inc" 155 #endif 156 157 // --------------- sanitizer_libc.h 158 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD 159 #if !SANITIZER_S390 160 uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd, 161 u64 offset) { 162 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS 163 return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd, 164 offset); 165 #else 166 // mmap2 specifies file offset in 4096-byte units. 167 CHECK(IsAligned(offset, 4096)); 168 return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd, 169 offset / 4096); 170 #endif 171 } 172 #endif // !SANITIZER_S390 173 174 uptr internal_munmap(void *addr, uptr length) { 175 return internal_syscall(SYSCALL(munmap), (uptr)addr, length); 176 } 177 178 int internal_mprotect(void *addr, uptr length, int prot) { 179 return internal_syscall(SYSCALL(mprotect), (uptr)addr, length, prot); 180 } 181 182 int internal_madvise(uptr addr, uptr length, int advice) { 183 return internal_syscall(SYSCALL(madvise), addr, length, advice); 184 } 185 186 uptr internal_close(fd_t fd) { 187 return internal_syscall(SYSCALL(close), fd); 188 } 189 190 uptr internal_open(const char *filename, int flags) { 191 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 192 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags); 193 #else 194 return internal_syscall(SYSCALL(open), (uptr)filename, flags); 195 #endif 196 } 197 198 uptr internal_open(const char *filename, int flags, u32 mode) { 199 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 200 return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags, 201 mode); 202 #else 203 return internal_syscall(SYSCALL(open), (uptr)filename, flags, mode); 204 #endif 205 } 206 207 uptr internal_read(fd_t fd, void *buf, uptr count) { 208 sptr res; 209 HANDLE_EINTR(res, 210 (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf, count)); 211 return res; 212 } 213 214 uptr internal_write(fd_t fd, const void *buf, uptr count) { 215 sptr res; 216 HANDLE_EINTR(res, 217 (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf, count)); 218 return res; 219 } 220 221 uptr internal_ftruncate(fd_t fd, uptr size) { 222 sptr res; 223 HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd, 224 (OFF_T)size)); 225 return res; 226 } 227 228 #if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && SANITIZER_LINUX 229 static void stat64_to_stat(struct stat64 *in, struct stat *out) { 230 internal_memset(out, 0, sizeof(*out)); 231 out->st_dev = in->st_dev; 232 out->st_ino = in->st_ino; 233 out->st_mode = in->st_mode; 234 out->st_nlink = in->st_nlink; 235 out->st_uid = in->st_uid; 236 out->st_gid = in->st_gid; 237 out->st_rdev = in->st_rdev; 238 out->st_size = in->st_size; 239 out->st_blksize = in->st_blksize; 240 out->st_blocks = in->st_blocks; 241 out->st_atime = in->st_atime; 242 out->st_mtime = in->st_mtime; 243 out->st_ctime = in->st_ctime; 244 } 245 #endif 246 247 #if defined(__mips64) 248 // Undefine compatibility macros from <sys/stat.h> 249 // so that they would not clash with the kernel_stat 250 // st_[a|m|c]time fields 251 #undef st_atime 252 #undef st_mtime 253 #undef st_ctime 254 #if defined(SANITIZER_ANDROID) 255 // Bionic sys/stat.h defines additional macros 256 // for compatibility with the old NDKs and 257 // they clash with the kernel_stat structure 258 // st_[a|m|c]time_nsec fields. 259 #undef st_atime_nsec 260 #undef st_mtime_nsec 261 #undef st_ctime_nsec 262 #endif 263 static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) { 264 internal_memset(out, 0, sizeof(*out)); 265 out->st_dev = in->st_dev; 266 out->st_ino = in->st_ino; 267 out->st_mode = in->st_mode; 268 out->st_nlink = in->st_nlink; 269 out->st_uid = in->st_uid; 270 out->st_gid = in->st_gid; 271 out->st_rdev = in->st_rdev; 272 out->st_size = in->st_size; 273 out->st_blksize = in->st_blksize; 274 out->st_blocks = in->st_blocks; 275 #if defined(__USE_MISC) || \ 276 defined(__USE_XOPEN2K8) || \ 277 defined(SANITIZER_ANDROID) 278 out->st_atim.tv_sec = in->st_atime; 279 out->st_atim.tv_nsec = in->st_atime_nsec; 280 out->st_mtim.tv_sec = in->st_mtime; 281 out->st_mtim.tv_nsec = in->st_mtime_nsec; 282 out->st_ctim.tv_sec = in->st_ctime; 283 out->st_ctim.tv_nsec = in->st_ctime_nsec; 284 #else 285 out->st_atime = in->st_atime; 286 out->st_atimensec = in->st_atime_nsec; 287 out->st_mtime = in->st_mtime; 288 out->st_mtimensec = in->st_mtime_nsec; 289 out->st_ctime = in->st_ctime; 290 out->st_atimensec = in->st_ctime_nsec; 291 #endif 292 } 293 #endif 294 295 uptr internal_stat(const char *path, void *buf) { 296 #if SANITIZER_FREEBSD 297 return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0); 298 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 299 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf, 300 0); 301 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS 302 # if defined(__mips64) 303 // For mips64, stat syscall fills buffer in the format of kernel_stat 304 struct kernel_stat kbuf; 305 int res = internal_syscall(SYSCALL(stat), path, &kbuf); 306 kernel_stat_to_stat(&kbuf, (struct stat *)buf); 307 return res; 308 # else 309 return internal_syscall(SYSCALL(stat), (uptr)path, (uptr)buf); 310 # endif 311 #else 312 struct stat64 buf64; 313 int res = internal_syscall(SYSCALL(stat64), path, &buf64); 314 stat64_to_stat(&buf64, (struct stat *)buf); 315 return res; 316 #endif 317 } 318 319 uptr internal_lstat(const char *path, void *buf) { 320 #if SANITIZER_FREEBSD 321 return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 322 AT_SYMLINK_NOFOLLOW); 323 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 324 return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf, 325 AT_SYMLINK_NOFOLLOW); 326 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS 327 # if SANITIZER_MIPS64 328 // For mips64, lstat syscall fills buffer in the format of kernel_stat 329 struct kernel_stat kbuf; 330 int res = internal_syscall(SYSCALL(lstat), path, &kbuf); 331 kernel_stat_to_stat(&kbuf, (struct stat *)buf); 332 return res; 333 # else 334 return internal_syscall(SYSCALL(lstat), (uptr)path, (uptr)buf); 335 # endif 336 #else 337 struct stat64 buf64; 338 int res = internal_syscall(SYSCALL(lstat64), path, &buf64); 339 stat64_to_stat(&buf64, (struct stat *)buf); 340 return res; 341 #endif 342 } 343 344 uptr internal_fstat(fd_t fd, void *buf) { 345 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS 346 #if SANITIZER_MIPS64 347 // For mips64, fstat syscall fills buffer in the format of kernel_stat 348 struct kernel_stat kbuf; 349 int res = internal_syscall(SYSCALL(fstat), fd, &kbuf); 350 kernel_stat_to_stat(&kbuf, (struct stat *)buf); 351 return res; 352 # else 353 return internal_syscall(SYSCALL(fstat), fd, (uptr)buf); 354 # endif 355 #else 356 struct stat64 buf64; 357 int res = internal_syscall(SYSCALL(fstat64), fd, &buf64); 358 stat64_to_stat(&buf64, (struct stat *)buf); 359 return res; 360 #endif 361 } 362 363 uptr internal_filesize(fd_t fd) { 364 struct stat st; 365 if (internal_fstat(fd, &st)) 366 return -1; 367 return (uptr)st.st_size; 368 } 369 370 uptr internal_dup(int oldfd) { 371 return internal_syscall(SYSCALL(dup), oldfd); 372 } 373 374 uptr internal_dup2(int oldfd, int newfd) { 375 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 376 return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0); 377 #else 378 return internal_syscall(SYSCALL(dup2), oldfd, newfd); 379 #endif 380 } 381 382 uptr internal_readlink(const char *path, char *buf, uptr bufsize) { 383 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 384 return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf, 385 bufsize); 386 #else 387 return internal_syscall(SYSCALL(readlink), (uptr)path, (uptr)buf, bufsize); 388 #endif 389 } 390 391 uptr internal_unlink(const char *path) { 392 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 393 return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0); 394 #else 395 return internal_syscall(SYSCALL(unlink), (uptr)path); 396 #endif 397 } 398 399 uptr internal_rename(const char *oldpath, const char *newpath) { 400 #if defined(__riscv) 401 return internal_syscall(SYSCALL(renameat2), AT_FDCWD, (uptr)oldpath, AT_FDCWD, 402 (uptr)newpath, 0); 403 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 404 return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD, 405 (uptr)newpath); 406 #else 407 return internal_syscall(SYSCALL(rename), (uptr)oldpath, (uptr)newpath); 408 #endif 409 } 410 411 uptr internal_sched_yield() { 412 return internal_syscall(SYSCALL(sched_yield)); 413 } 414 415 unsigned int internal_sleep(unsigned int seconds) { 416 struct timespec ts; 417 ts.tv_sec = seconds; 418 ts.tv_nsec = 0; 419 int res = internal_syscall(SYSCALL(nanosleep), &ts, &ts); 420 if (res) return ts.tv_sec; 421 return 0; 422 } 423 424 uptr internal_execve(const char *filename, char *const argv[], 425 char *const envp[]) { 426 return internal_syscall(SYSCALL(execve), (uptr)filename, (uptr)argv, 427 (uptr)envp); 428 } 429 #endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD 430 431 #if !SANITIZER_NETBSD 432 void internal__exit(int exitcode) { 433 #if SANITIZER_FREEBSD || SANITIZER_SOLARIS 434 internal_syscall(SYSCALL(exit), exitcode); 435 #else 436 internal_syscall(SYSCALL(exit_group), exitcode); 437 #endif 438 Die(); // Unreachable. 439 } 440 #endif // !SANITIZER_NETBSD 441 442 // ----------------- sanitizer_common.h 443 bool FileExists(const char *filename) { 444 if (ShouldMockFailureToOpen(filename)) 445 return false; 446 struct stat st; 447 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 448 if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0)) 449 #else 450 if (internal_stat(filename, &st)) 451 #endif 452 return false; 453 // Sanity check: filename is a regular file. 454 return S_ISREG(st.st_mode); 455 } 456 457 #if !SANITIZER_NETBSD 458 tid_t GetTid() { 459 #if SANITIZER_FREEBSD 460 long Tid; 461 thr_self(&Tid); 462 return Tid; 463 #elif SANITIZER_SOLARIS 464 return thr_self(); 465 #else 466 return internal_syscall(SYSCALL(gettid)); 467 #endif 468 } 469 470 int TgKill(pid_t pid, tid_t tid, int sig) { 471 #if SANITIZER_LINUX 472 return internal_syscall(SYSCALL(tgkill), pid, tid, sig); 473 #elif SANITIZER_FREEBSD 474 return internal_syscall(SYSCALL(thr_kill2), pid, tid, sig); 475 #elif SANITIZER_SOLARIS 476 (void)pid; 477 return thr_kill(tid, sig); 478 #endif 479 } 480 #endif 481 482 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD 483 u64 NanoTime() { 484 #if SANITIZER_FREEBSD 485 timeval tv; 486 #else 487 kernel_timeval tv; 488 #endif 489 internal_memset(&tv, 0, sizeof(tv)); 490 internal_syscall(SYSCALL(gettimeofday), &tv, 0); 491 return (u64)tv.tv_sec * 1000*1000*1000 + tv.tv_usec * 1000; 492 } 493 494 uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp) { 495 return internal_syscall(SYSCALL(clock_gettime), clk_id, tp); 496 } 497 #endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD 498 499 // Like getenv, but reads env directly from /proc (on Linux) or parses the 500 // 'environ' array (on some others) and does not use libc. This function 501 // should be called first inside __asan_init. 502 const char *GetEnv(const char *name) { 503 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_SOLARIS 504 if (::environ != 0) { 505 uptr NameLen = internal_strlen(name); 506 for (char **Env = ::environ; *Env != 0; Env++) { 507 if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=') 508 return (*Env) + NameLen + 1; 509 } 510 } 511 return 0; // Not found. 512 #elif SANITIZER_LINUX 513 static char *environ; 514 static uptr len; 515 static bool inited; 516 if (!inited) { 517 inited = true; 518 uptr environ_size; 519 if (!ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, &len)) 520 environ = nullptr; 521 } 522 if (!environ || len == 0) return nullptr; 523 uptr namelen = internal_strlen(name); 524 const char *p = environ; 525 while (*p != '\0') { // will happen at the \0\0 that terminates the buffer 526 // proc file has the format NAME=value\0NAME=value\0NAME=value\0... 527 const char* endp = 528 (char*)internal_memchr(p, '\0', len - (p - environ)); 529 if (!endp) // this entry isn't NUL terminated 530 return nullptr; 531 else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=') // Match. 532 return p + namelen + 1; // point after = 533 p = endp + 1; 534 } 535 return nullptr; // Not found. 536 #else 537 #error "Unsupported platform" 538 #endif 539 } 540 541 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD && !SANITIZER_GO 542 extern "C" { 543 SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end; 544 } 545 #endif 546 547 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD 548 static void ReadNullSepFileToArray(const char *path, char ***arr, 549 int arr_size) { 550 char *buff; 551 uptr buff_size; 552 uptr buff_len; 553 *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray"); 554 if (!ReadFileToBuffer(path, &buff, &buff_size, &buff_len, 1024 * 1024)) { 555 (*arr)[0] = nullptr; 556 return; 557 } 558 (*arr)[0] = buff; 559 int count, i; 560 for (count = 1, i = 1; ; i++) { 561 if (buff[i] == 0) { 562 if (buff[i+1] == 0) break; 563 (*arr)[count] = &buff[i+1]; 564 CHECK_LE(count, arr_size - 1); // FIXME: make this more flexible. 565 count++; 566 } 567 } 568 (*arr)[count] = nullptr; 569 } 570 #endif 571 572 static void GetArgsAndEnv(char ***argv, char ***envp) { 573 #if SANITIZER_FREEBSD 574 // On FreeBSD, retrieving the argument and environment arrays is done via the 575 // kern.ps_strings sysctl, which returns a pointer to a structure containing 576 // this information. See also <sys/exec.h>. 577 ps_strings *pss; 578 uptr sz = sizeof(pss); 579 if (internal_sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) { 580 Printf("sysctl kern.ps_strings failed\n"); 581 Die(); 582 } 583 *argv = pss->ps_argvstr; 584 *envp = pss->ps_envstr; 585 #elif SANITIZER_NETBSD 586 *argv = __ps_strings->ps_argvstr; 587 *envp = __ps_strings->ps_envstr; 588 #else // SANITIZER_FREEBSD 589 #if !SANITIZER_GO 590 if (&__libc_stack_end) { 591 uptr* stack_end = (uptr*)__libc_stack_end; 592 // Normally argc can be obtained from *stack_end, however, on ARM glibc's 593 // _start clobbers it: 594 // https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/arm/start.S;hb=refs/heads/release/2.31/master#l75 595 // Do not special-case ARM and infer argc from argv everywhere. 596 int argc = 0; 597 while (stack_end[argc + 1]) argc++; 598 *argv = (char**)(stack_end + 1); 599 *envp = (char**)(stack_end + argc + 2); 600 } else { 601 #endif // !SANITIZER_GO 602 static const int kMaxArgv = 2000, kMaxEnvp = 2000; 603 ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv); 604 ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp); 605 #if !SANITIZER_GO 606 } 607 #endif // !SANITIZER_GO 608 #endif // SANITIZER_FREEBSD 609 } 610 611 char **GetArgv() { 612 char **argv, **envp; 613 GetArgsAndEnv(&argv, &envp); 614 return argv; 615 } 616 617 char **GetEnviron() { 618 char **argv, **envp; 619 GetArgsAndEnv(&argv, &envp); 620 return envp; 621 } 622 623 #if !SANITIZER_SOLARIS 624 enum MutexState { 625 MtxUnlocked = 0, 626 MtxLocked = 1, 627 MtxSleeping = 2 628 }; 629 630 BlockingMutex::BlockingMutex() { 631 internal_memset(this, 0, sizeof(*this)); 632 } 633 634 void BlockingMutex::Lock() { 635 CHECK_EQ(owner_, 0); 636 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_); 637 if (atomic_exchange(m, MtxLocked, memory_order_acquire) == MtxUnlocked) 638 return; 639 while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked) { 640 #if SANITIZER_FREEBSD 641 _umtx_op(m, UMTX_OP_WAIT_UINT, MtxSleeping, 0, 0); 642 #elif SANITIZER_NETBSD 643 sched_yield(); /* No userspace futex-like synchronization */ 644 #else 645 internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAIT_PRIVATE, MtxSleeping, 646 0, 0, 0); 647 #endif 648 } 649 } 650 651 void BlockingMutex::Unlock() { 652 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_); 653 u32 v = atomic_exchange(m, MtxUnlocked, memory_order_release); 654 CHECK_NE(v, MtxUnlocked); 655 if (v == MtxSleeping) { 656 #if SANITIZER_FREEBSD 657 _umtx_op(m, UMTX_OP_WAKE, 1, 0, 0); 658 #elif SANITIZER_NETBSD 659 /* No userspace futex-like synchronization */ 660 #else 661 internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAKE_PRIVATE, 1, 0, 0, 0); 662 #endif 663 } 664 } 665 666 void BlockingMutex::CheckLocked() { 667 atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_); 668 CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed)); 669 } 670 #endif // !SANITIZER_SOLARIS 671 672 // ----------------- sanitizer_linux.h 673 // The actual size of this structure is specified by d_reclen. 674 // Note that getdents64 uses a different structure format. We only provide the 675 // 32-bit syscall here. 676 #if SANITIZER_NETBSD 677 // Not used 678 #else 679 struct linux_dirent { 680 #if SANITIZER_X32 || defined(__aarch64__) || SANITIZER_RISCV64 681 u64 d_ino; 682 u64 d_off; 683 #else 684 unsigned long d_ino; 685 unsigned long d_off; 686 #endif 687 unsigned short d_reclen; 688 #if defined(__aarch64__) || SANITIZER_RISCV64 689 unsigned char d_type; 690 #endif 691 char d_name[256]; 692 }; 693 #endif 694 695 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD 696 // Syscall wrappers. 697 uptr internal_ptrace(int request, int pid, void *addr, void *data) { 698 return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr, 699 (uptr)data); 700 } 701 702 uptr internal_waitpid(int pid, int *status, int options) { 703 return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options, 704 0 /* rusage */); 705 } 706 707 uptr internal_getpid() { 708 return internal_syscall(SYSCALL(getpid)); 709 } 710 711 uptr internal_getppid() { 712 return internal_syscall(SYSCALL(getppid)); 713 } 714 715 int internal_dlinfo(void *handle, int request, void *p) { 716 #if SANITIZER_FREEBSD 717 return dlinfo(handle, request, p); 718 #else 719 UNIMPLEMENTED(); 720 #endif 721 } 722 723 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) { 724 #if SANITIZER_FREEBSD 725 return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL); 726 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 727 return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count); 728 #else 729 return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count); 730 #endif 731 } 732 733 uptr internal_lseek(fd_t fd, OFF_T offset, int whence) { 734 return internal_syscall(SYSCALL(lseek), fd, offset, whence); 735 } 736 737 #if SANITIZER_LINUX 738 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) { 739 return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5); 740 } 741 #endif 742 743 uptr internal_sigaltstack(const void *ss, void *oss) { 744 return internal_syscall(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss); 745 } 746 747 int internal_fork() { 748 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS 749 return internal_syscall(SYSCALL(clone), SIGCHLD, 0); 750 #else 751 return internal_syscall(SYSCALL(fork)); 752 #endif 753 } 754 755 #if SANITIZER_FREEBSD 756 int internal_sysctl(const int *name, unsigned int namelen, void *oldp, 757 uptr *oldlenp, const void *newp, uptr newlen) { 758 return internal_syscall(SYSCALL(__sysctl), name, namelen, oldp, 759 (size_t *)oldlenp, newp, (size_t)newlen); 760 } 761 762 int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp, 763 const void *newp, uptr newlen) { 764 // Note: this function can be called during startup, so we need to avoid 765 // calling any interceptable functions. On FreeBSD >= 1300045 sysctlbyname() 766 // is a real syscall, but for older versions it calls sysctlnametomib() 767 // followed by sysctl(). To avoid calling the intercepted version and 768 // asserting if this happens during startup, call the real sysctlnametomib() 769 // followed by internal_sysctl() if the syscall is not available. 770 #ifdef SYS___sysctlbyname 771 return internal_syscall(SYSCALL(__sysctlbyname), sname, 772 internal_strlen(sname), oldp, (size_t *)oldlenp, newp, 773 (size_t)newlen); 774 #else 775 static decltype(sysctlnametomib) *real_sysctlnametomib = nullptr; 776 if (!real_sysctlnametomib) 777 real_sysctlnametomib = 778 (decltype(sysctlnametomib) *)dlsym(RTLD_NEXT, "sysctlnametomib"); 779 CHECK(real_sysctlnametomib); 780 781 int oid[CTL_MAXNAME]; 782 size_t len = CTL_MAXNAME; 783 if (real_sysctlnametomib(sname, oid, &len) == -1) 784 return (-1); 785 return internal_sysctl(oid, len, oldp, oldlenp, newp, newlen); 786 #endif 787 } 788 #endif 789 790 #if SANITIZER_LINUX 791 #define SA_RESTORER 0x04000000 792 // Doesn't set sa_restorer if the caller did not set it, so use with caution 793 //(see below). 794 int internal_sigaction_norestorer(int signum, const void *act, void *oldact) { 795 __sanitizer_kernel_sigaction_t k_act, k_oldact; 796 internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t)); 797 internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t)); 798 const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act; 799 __sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact; 800 if (u_act) { 801 k_act.handler = u_act->handler; 802 k_act.sigaction = u_act->sigaction; 803 internal_memcpy(&k_act.sa_mask, &u_act->sa_mask, 804 sizeof(__sanitizer_kernel_sigset_t)); 805 // Without SA_RESTORER kernel ignores the calls (probably returns EINVAL). 806 k_act.sa_flags = u_act->sa_flags | SA_RESTORER; 807 // FIXME: most often sa_restorer is unset, however the kernel requires it 808 // to point to a valid signal restorer that calls the rt_sigreturn syscall. 809 // If sa_restorer passed to the kernel is NULL, the program may crash upon 810 // signal delivery or fail to unwind the stack in the signal handler. 811 // libc implementation of sigaction() passes its own restorer to 812 // rt_sigaction, so we need to do the same (we'll need to reimplement the 813 // restorers; for x86_64 the restorer address can be obtained from 814 // oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact). 815 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32 816 k_act.sa_restorer = u_act->sa_restorer; 817 #endif 818 } 819 820 uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum, 821 (uptr)(u_act ? &k_act : nullptr), 822 (uptr)(u_oldact ? &k_oldact : nullptr), 823 (uptr)sizeof(__sanitizer_kernel_sigset_t)); 824 825 if ((result == 0) && u_oldact) { 826 u_oldact->handler = k_oldact.handler; 827 u_oldact->sigaction = k_oldact.sigaction; 828 internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask, 829 sizeof(__sanitizer_kernel_sigset_t)); 830 u_oldact->sa_flags = k_oldact.sa_flags; 831 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32 832 u_oldact->sa_restorer = k_oldact.sa_restorer; 833 #endif 834 } 835 return result; 836 } 837 #endif // SANITIZER_LINUX 838 839 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set, 840 __sanitizer_sigset_t *oldset) { 841 #if SANITIZER_FREEBSD 842 return internal_syscall(SYSCALL(sigprocmask), how, set, oldset); 843 #else 844 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set; 845 __sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset; 846 return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how, (uptr)k_set, 847 (uptr)k_oldset, sizeof(__sanitizer_kernel_sigset_t)); 848 #endif 849 } 850 851 void internal_sigfillset(__sanitizer_sigset_t *set) { 852 internal_memset(set, 0xff, sizeof(*set)); 853 } 854 855 void internal_sigemptyset(__sanitizer_sigset_t *set) { 856 internal_memset(set, 0, sizeof(*set)); 857 } 858 859 #if SANITIZER_LINUX 860 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) { 861 signum -= 1; 862 CHECK_GE(signum, 0); 863 CHECK_LT(signum, sizeof(*set) * 8); 864 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set; 865 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8); 866 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8); 867 k_set->sig[idx] &= ~(1 << bit); 868 } 869 870 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) { 871 signum -= 1; 872 CHECK_GE(signum, 0); 873 CHECK_LT(signum, sizeof(*set) * 8); 874 __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set; 875 const uptr idx = signum / (sizeof(k_set->sig[0]) * 8); 876 const uptr bit = signum % (sizeof(k_set->sig[0]) * 8); 877 return k_set->sig[idx] & (1 << bit); 878 } 879 #elif SANITIZER_FREEBSD 880 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) { 881 sigset_t *rset = reinterpret_cast<sigset_t *>(set); 882 sigdelset(rset, signum); 883 } 884 885 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) { 886 sigset_t *rset = reinterpret_cast<sigset_t *>(set); 887 return sigismember(rset, signum); 888 } 889 #endif 890 #endif // !SANITIZER_SOLARIS 891 892 #if !SANITIZER_NETBSD 893 // ThreadLister implementation. 894 ThreadLister::ThreadLister(pid_t pid) : pid_(pid), buffer_(4096) { 895 char task_directory_path[80]; 896 internal_snprintf(task_directory_path, sizeof(task_directory_path), 897 "/proc/%d/task/", pid); 898 descriptor_ = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY); 899 if (internal_iserror(descriptor_)) { 900 Report("Can't open /proc/%d/task for reading.\n", pid); 901 } 902 } 903 904 ThreadLister::Result ThreadLister::ListThreads( 905 InternalMmapVector<tid_t> *threads) { 906 if (internal_iserror(descriptor_)) 907 return Error; 908 internal_lseek(descriptor_, 0, SEEK_SET); 909 threads->clear(); 910 911 Result result = Ok; 912 for (bool first_read = true;; first_read = false) { 913 // Resize to max capacity if it was downsized by IsAlive. 914 buffer_.resize(buffer_.capacity()); 915 CHECK_GE(buffer_.size(), 4096); 916 uptr read = internal_getdents( 917 descriptor_, (struct linux_dirent *)buffer_.data(), buffer_.size()); 918 if (!read) 919 return result; 920 if (internal_iserror(read)) { 921 Report("Can't read directory entries from /proc/%d/task.\n", pid_); 922 return Error; 923 } 924 925 for (uptr begin = (uptr)buffer_.data(), end = begin + read; begin < end;) { 926 struct linux_dirent *entry = (struct linux_dirent *)begin; 927 begin += entry->d_reclen; 928 if (entry->d_ino == 1) { 929 // Inode 1 is for bad blocks and also can be a reason for early return. 930 // Should be emitted if kernel tried to output terminating thread. 931 // See proc_task_readdir implementation in Linux. 932 result = Incomplete; 933 } 934 if (entry->d_ino && *entry->d_name >= '0' && *entry->d_name <= '9') 935 threads->push_back(internal_atoll(entry->d_name)); 936 } 937 938 // Now we are going to detect short-read or early EOF. In such cases Linux 939 // can return inconsistent list with missing alive threads. 940 // Code will just remember that the list can be incomplete but it will 941 // continue reads to return as much as possible. 942 if (!first_read) { 943 // The first one was a short-read by definition. 944 result = Incomplete; 945 } else if (read > buffer_.size() - 1024) { 946 // Read was close to the buffer size. So double the size and assume the 947 // worst. 948 buffer_.resize(buffer_.size() * 2); 949 result = Incomplete; 950 } else if (!threads->empty() && !IsAlive(threads->back())) { 951 // Maybe Linux early returned from read on terminated thread (!pid_alive) 952 // and failed to restore read position. 953 // See next_tid and proc_task_instantiate in Linux. 954 result = Incomplete; 955 } 956 } 957 } 958 959 bool ThreadLister::IsAlive(int tid) { 960 // /proc/%d/task/%d/status uses same call to detect alive threads as 961 // proc_task_readdir. See task_state implementation in Linux. 962 char path[80]; 963 internal_snprintf(path, sizeof(path), "/proc/%d/task/%d/status", pid_, tid); 964 if (!ReadFileToVector(path, &buffer_) || buffer_.empty()) 965 return false; 966 buffer_.push_back(0); 967 static const char kPrefix[] = "\nPPid:"; 968 const char *field = internal_strstr(buffer_.data(), kPrefix); 969 if (!field) 970 return false; 971 field += internal_strlen(kPrefix); 972 return (int)internal_atoll(field) != 0; 973 } 974 975 ThreadLister::~ThreadLister() { 976 if (!internal_iserror(descriptor_)) 977 internal_close(descriptor_); 978 } 979 #endif 980 981 #if SANITIZER_WORDSIZE == 32 982 // Take care of unusable kernel area in top gigabyte. 983 static uptr GetKernelAreaSize() { 984 #if SANITIZER_LINUX && !SANITIZER_X32 985 const uptr gbyte = 1UL << 30; 986 987 // Firstly check if there are writable segments 988 // mapped to top gigabyte (e.g. stack). 989 MemoryMappingLayout proc_maps(/*cache_enabled*/true); 990 if (proc_maps.Error()) 991 return 0; 992 MemoryMappedSegment segment; 993 while (proc_maps.Next(&segment)) { 994 if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0; 995 } 996 997 #if !SANITIZER_ANDROID 998 // Even if nothing is mapped, top Gb may still be accessible 999 // if we are running on 64-bit kernel. 1000 // Uname may report misleading results if personality type 1001 // is modified (e.g. under schroot) so check this as well. 1002 struct utsname uname_info; 1003 int pers = personality(0xffffffffUL); 1004 if (!(pers & PER_MASK) && internal_uname(&uname_info) == 0 && 1005 internal_strstr(uname_info.machine, "64")) 1006 return 0; 1007 #endif // SANITIZER_ANDROID 1008 1009 // Top gigabyte is reserved for kernel. 1010 return gbyte; 1011 #else 1012 return 0; 1013 #endif // SANITIZER_LINUX && !SANITIZER_X32 1014 } 1015 #endif // SANITIZER_WORDSIZE == 32 1016 1017 uptr GetMaxVirtualAddress() { 1018 #if SANITIZER_NETBSD && defined(__x86_64__) 1019 return 0x7f7ffffff000ULL; // (0x00007f8000000000 - PAGE_SIZE) 1020 #elif SANITIZER_WORDSIZE == 64 1021 # if defined(__powerpc64__) || defined(__aarch64__) 1022 // On PowerPC64 we have two different address space layouts: 44- and 46-bit. 1023 // We somehow need to figure out which one we are using now and choose 1024 // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL. 1025 // Note that with 'ulimit -s unlimited' the stack is moved away from the top 1026 // of the address space, so simply checking the stack address is not enough. 1027 // This should (does) work for both PowerPC64 Endian modes. 1028 // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit. 1029 return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1; 1030 #elif SANITIZER_RISCV64 1031 return (1ULL << 38) - 1; 1032 # elif defined(__mips64) 1033 return (1ULL << 40) - 1; // 0x000000ffffffffffUL; 1034 # elif defined(__s390x__) 1035 return (1ULL << 53) - 1; // 0x001fffffffffffffUL; 1036 #elif defined(__sparc__) 1037 return ~(uptr)0; 1038 # else 1039 return (1ULL << 47) - 1; // 0x00007fffffffffffUL; 1040 # endif 1041 #else // SANITIZER_WORDSIZE == 32 1042 # if defined(__s390__) 1043 return (1ULL << 31) - 1; // 0x7fffffff; 1044 # else 1045 return (1ULL << 32) - 1; // 0xffffffff; 1046 # endif 1047 #endif // SANITIZER_WORDSIZE 1048 } 1049 1050 uptr GetMaxUserVirtualAddress() { 1051 uptr addr = GetMaxVirtualAddress(); 1052 #if SANITIZER_WORDSIZE == 32 && !defined(__s390__) 1053 if (!common_flags()->full_address_space) 1054 addr -= GetKernelAreaSize(); 1055 CHECK_LT(reinterpret_cast<uptr>(&addr), addr); 1056 #endif 1057 return addr; 1058 } 1059 1060 #if !SANITIZER_ANDROID 1061 uptr GetPageSize() { 1062 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__)) && \ 1063 defined(EXEC_PAGESIZE) 1064 return EXEC_PAGESIZE; 1065 #elif SANITIZER_FREEBSD || SANITIZER_NETBSD 1066 // Use sysctl as sysconf can trigger interceptors internally. 1067 int pz = 0; 1068 uptr pzl = sizeof(pz); 1069 int mib[2] = {CTL_HW, HW_PAGESIZE}; 1070 int rv = internal_sysctl(mib, 2, &pz, &pzl, nullptr, 0); 1071 CHECK_EQ(rv, 0); 1072 return (uptr)pz; 1073 #elif SANITIZER_USE_GETAUXVAL 1074 return getauxval(AT_PAGESZ); 1075 #else 1076 return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy. 1077 #endif 1078 } 1079 #endif // !SANITIZER_ANDROID 1080 1081 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) { 1082 #if SANITIZER_SOLARIS 1083 const char *default_module_name = getexecname(); 1084 CHECK_NE(default_module_name, NULL); 1085 return internal_snprintf(buf, buf_len, "%s", default_module_name); 1086 #else 1087 #if SANITIZER_FREEBSD || SANITIZER_NETBSD 1088 #if SANITIZER_FREEBSD 1089 const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1}; 1090 #else 1091 const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME}; 1092 #endif 1093 const char *default_module_name = "kern.proc.pathname"; 1094 uptr Size = buf_len; 1095 bool IsErr = 1096 (internal_sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0); 1097 int readlink_error = IsErr ? errno : 0; 1098 uptr module_name_len = Size; 1099 #else 1100 const char *default_module_name = "/proc/self/exe"; 1101 uptr module_name_len = internal_readlink( 1102 default_module_name, buf, buf_len); 1103 int readlink_error; 1104 bool IsErr = internal_iserror(module_name_len, &readlink_error); 1105 #endif // SANITIZER_SOLARIS 1106 if (IsErr) { 1107 // We can't read binary name for some reason, assume it's unknown. 1108 Report("WARNING: reading executable name failed with errno %d, " 1109 "some stack frames may not be symbolized\n", readlink_error); 1110 module_name_len = internal_snprintf(buf, buf_len, "%s", 1111 default_module_name); 1112 CHECK_LT(module_name_len, buf_len); 1113 } 1114 return module_name_len; 1115 #endif 1116 } 1117 1118 uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) { 1119 #if SANITIZER_LINUX 1120 char *tmpbuf; 1121 uptr tmpsize; 1122 uptr tmplen; 1123 if (ReadFileToBuffer("/proc/self/cmdline", &tmpbuf, &tmpsize, &tmplen, 1124 1024 * 1024)) { 1125 internal_strncpy(buf, tmpbuf, buf_len); 1126 UnmapOrDie(tmpbuf, tmpsize); 1127 return internal_strlen(buf); 1128 } 1129 #endif 1130 return ReadBinaryName(buf, buf_len); 1131 } 1132 1133 // Match full names of the form /path/to/base_name{-,.}* 1134 bool LibraryNameIs(const char *full_name, const char *base_name) { 1135 const char *name = full_name; 1136 // Strip path. 1137 while (*name != '\0') name++; 1138 while (name > full_name && *name != '/') name--; 1139 if (*name == '/') name++; 1140 uptr base_name_length = internal_strlen(base_name); 1141 if (internal_strncmp(name, base_name, base_name_length)) return false; 1142 return (name[base_name_length] == '-' || name[base_name_length] == '.'); 1143 } 1144 1145 #if !SANITIZER_ANDROID 1146 // Call cb for each region mapped by map. 1147 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) { 1148 CHECK_NE(map, nullptr); 1149 #if !SANITIZER_FREEBSD 1150 typedef ElfW(Phdr) Elf_Phdr; 1151 typedef ElfW(Ehdr) Elf_Ehdr; 1152 #endif // !SANITIZER_FREEBSD 1153 char *base = (char *)map->l_addr; 1154 Elf_Ehdr *ehdr = (Elf_Ehdr *)base; 1155 char *phdrs = base + ehdr->e_phoff; 1156 char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize; 1157 1158 // Find the segment with the minimum base so we can "relocate" the p_vaddr 1159 // fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC 1160 // objects have a non-zero base. 1161 uptr preferred_base = (uptr)-1; 1162 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) { 1163 Elf_Phdr *phdr = (Elf_Phdr *)iter; 1164 if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr) 1165 preferred_base = (uptr)phdr->p_vaddr; 1166 } 1167 1168 // Compute the delta from the real base to get a relocation delta. 1169 sptr delta = (uptr)base - preferred_base; 1170 // Now we can figure out what the loader really mapped. 1171 for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) { 1172 Elf_Phdr *phdr = (Elf_Phdr *)iter; 1173 if (phdr->p_type == PT_LOAD) { 1174 uptr seg_start = phdr->p_vaddr + delta; 1175 uptr seg_end = seg_start + phdr->p_memsz; 1176 // None of these values are aligned. We consider the ragged edges of the 1177 // load command as defined, since they are mapped from the file. 1178 seg_start = RoundDownTo(seg_start, GetPageSizeCached()); 1179 seg_end = RoundUpTo(seg_end, GetPageSizeCached()); 1180 cb((void *)seg_start, seg_end - seg_start); 1181 } 1182 } 1183 } 1184 #endif 1185 1186 #if defined(__x86_64__) && SANITIZER_LINUX 1187 // We cannot use glibc's clone wrapper, because it messes with the child 1188 // task's TLS. It writes the PID and TID of the child task to its thread 1189 // descriptor, but in our case the child task shares the thread descriptor with 1190 // the parent (because we don't know how to allocate a new thread 1191 // descriptor to keep glibc happy). So the stock version of clone(), when 1192 // used with CLONE_VM, would end up corrupting the parent's thread descriptor. 1193 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1194 int *parent_tidptr, void *newtls, int *child_tidptr) { 1195 long long res; 1196 if (!fn || !child_stack) 1197 return -EINVAL; 1198 CHECK_EQ(0, (uptr)child_stack % 16); 1199 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long); 1200 ((unsigned long long *)child_stack)[0] = (uptr)fn; 1201 ((unsigned long long *)child_stack)[1] = (uptr)arg; 1202 register void *r8 __asm__("r8") = newtls; 1203 register int *r10 __asm__("r10") = child_tidptr; 1204 __asm__ __volatile__( 1205 /* %rax = syscall(%rax = SYSCALL(clone), 1206 * %rdi = flags, 1207 * %rsi = child_stack, 1208 * %rdx = parent_tidptr, 1209 * %r8 = new_tls, 1210 * %r10 = child_tidptr) 1211 */ 1212 "syscall\n" 1213 1214 /* if (%rax != 0) 1215 * return; 1216 */ 1217 "testq %%rax,%%rax\n" 1218 "jnz 1f\n" 1219 1220 /* In the child. Terminate unwind chain. */ 1221 // XXX: We should also terminate the CFI unwind chain 1222 // here. Unfortunately clang 3.2 doesn't support the 1223 // necessary CFI directives, so we skip that part. 1224 "xorq %%rbp,%%rbp\n" 1225 1226 /* Call "fn(arg)". */ 1227 "popq %%rax\n" 1228 "popq %%rdi\n" 1229 "call *%%rax\n" 1230 1231 /* Call _exit(%rax). */ 1232 "movq %%rax,%%rdi\n" 1233 "movq %2,%%rax\n" 1234 "syscall\n" 1235 1236 /* Return to parent. */ 1237 "1:\n" 1238 : "=a" (res) 1239 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)), 1240 "S"(child_stack), 1241 "D"(flags), 1242 "d"(parent_tidptr), 1243 "r"(r8), 1244 "r"(r10) 1245 : "memory", "r11", "rcx"); 1246 return res; 1247 } 1248 #elif defined(__mips__) 1249 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1250 int *parent_tidptr, void *newtls, int *child_tidptr) { 1251 long long res; 1252 if (!fn || !child_stack) 1253 return -EINVAL; 1254 CHECK_EQ(0, (uptr)child_stack % 16); 1255 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long); 1256 ((unsigned long long *)child_stack)[0] = (uptr)fn; 1257 ((unsigned long long *)child_stack)[1] = (uptr)arg; 1258 register void *a3 __asm__("$7") = newtls; 1259 register int *a4 __asm__("$8") = child_tidptr; 1260 // We don't have proper CFI directives here because it requires alot of code 1261 // for very marginal benefits. 1262 __asm__ __volatile__( 1263 /* $v0 = syscall($v0 = __NR_clone, 1264 * $a0 = flags, 1265 * $a1 = child_stack, 1266 * $a2 = parent_tidptr, 1267 * $a3 = new_tls, 1268 * $a4 = child_tidptr) 1269 */ 1270 ".cprestore 16;\n" 1271 "move $4,%1;\n" 1272 "move $5,%2;\n" 1273 "move $6,%3;\n" 1274 "move $7,%4;\n" 1275 /* Store the fifth argument on stack 1276 * if we are using 32-bit abi. 1277 */ 1278 #if SANITIZER_WORDSIZE == 32 1279 "lw %5,16($29);\n" 1280 #else 1281 "move $8,%5;\n" 1282 #endif 1283 "li $2,%6;\n" 1284 "syscall;\n" 1285 1286 /* if ($v0 != 0) 1287 * return; 1288 */ 1289 "bnez $2,1f;\n" 1290 1291 /* Call "fn(arg)". */ 1292 #if SANITIZER_WORDSIZE == 32 1293 #ifdef __BIG_ENDIAN__ 1294 "lw $25,4($29);\n" 1295 "lw $4,12($29);\n" 1296 #else 1297 "lw $25,0($29);\n" 1298 "lw $4,8($29);\n" 1299 #endif 1300 #else 1301 "ld $25,0($29);\n" 1302 "ld $4,8($29);\n" 1303 #endif 1304 "jal $25;\n" 1305 1306 /* Call _exit($v0). */ 1307 "move $4,$2;\n" 1308 "li $2,%7;\n" 1309 "syscall;\n" 1310 1311 /* Return to parent. */ 1312 "1:\n" 1313 : "=r" (res) 1314 : "r"(flags), 1315 "r"(child_stack), 1316 "r"(parent_tidptr), 1317 "r"(a3), 1318 "r"(a4), 1319 "i"(__NR_clone), 1320 "i"(__NR_exit) 1321 : "memory", "$29" ); 1322 return res; 1323 } 1324 #elif SANITIZER_RISCV64 1325 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1326 int *parent_tidptr, void *newtls, int *child_tidptr) { 1327 long long res; 1328 if (!fn || !child_stack) 1329 return -EINVAL; 1330 CHECK_EQ(0, (uptr)child_stack % 16); 1331 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long); 1332 ((unsigned long long *)child_stack)[0] = (uptr)fn; 1333 ((unsigned long long *)child_stack)[1] = (uptr)arg; 1334 1335 register int (*__fn)(void *) __asm__("a0") = fn; 1336 register void *__stack __asm__("a1") = child_stack; 1337 register int __flags __asm__("a2") = flags; 1338 register void *__arg __asm__("a3") = arg; 1339 register int *__ptid __asm__("a4") = parent_tidptr; 1340 register void *__tls __asm__("a5") = newtls; 1341 register int *__ctid __asm__("a6") = child_tidptr; 1342 1343 __asm__ __volatile__( 1344 "mv a0,a2\n" /* flags */ 1345 "mv a2,a4\n" /* ptid */ 1346 "mv a3,a5\n" /* tls */ 1347 "mv a4,a6\n" /* ctid */ 1348 "addi a7, zero, %9\n" /* clone */ 1349 1350 "ecall\n" 1351 1352 /* if (%r0 != 0) 1353 * return %r0; 1354 */ 1355 "bnez a0, 1f\n" 1356 1357 /* In the child, now. Call "fn(arg)". */ 1358 "ld a0, 8(sp)\n" 1359 "ld a1, 16(sp)\n" 1360 "jalr a1\n" 1361 1362 /* Call _exit(%r0). */ 1363 "addi a7, zero, %10\n" 1364 "ecall\n" 1365 "1:\n" 1366 1367 : "=r"(res) 1368 : "i"(-EINVAL), "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg), 1369 "r"(__ptid), "r"(__tls), "r"(__ctid), "i"(__NR_clone), "i"(__NR_exit) 1370 : "ra", "memory"); 1371 return res; 1372 } 1373 #elif defined(__aarch64__) 1374 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1375 int *parent_tidptr, void *newtls, int *child_tidptr) { 1376 long long res; 1377 if (!fn || !child_stack) 1378 return -EINVAL; 1379 CHECK_EQ(0, (uptr)child_stack % 16); 1380 child_stack = (char *)child_stack - 2 * sizeof(unsigned long long); 1381 ((unsigned long long *)child_stack)[0] = (uptr)fn; 1382 ((unsigned long long *)child_stack)[1] = (uptr)arg; 1383 1384 register int (*__fn)(void *) __asm__("x0") = fn; 1385 register void *__stack __asm__("x1") = child_stack; 1386 register int __flags __asm__("x2") = flags; 1387 register void *__arg __asm__("x3") = arg; 1388 register int *__ptid __asm__("x4") = parent_tidptr; 1389 register void *__tls __asm__("x5") = newtls; 1390 register int *__ctid __asm__("x6") = child_tidptr; 1391 1392 __asm__ __volatile__( 1393 "mov x0,x2\n" /* flags */ 1394 "mov x2,x4\n" /* ptid */ 1395 "mov x3,x5\n" /* tls */ 1396 "mov x4,x6\n" /* ctid */ 1397 "mov x8,%9\n" /* clone */ 1398 1399 "svc 0x0\n" 1400 1401 /* if (%r0 != 0) 1402 * return %r0; 1403 */ 1404 "cmp x0, #0\n" 1405 "bne 1f\n" 1406 1407 /* In the child, now. Call "fn(arg)". */ 1408 "ldp x1, x0, [sp], #16\n" 1409 "blr x1\n" 1410 1411 /* Call _exit(%r0). */ 1412 "mov x8, %10\n" 1413 "svc 0x0\n" 1414 "1:\n" 1415 1416 : "=r" (res) 1417 : "i"(-EINVAL), 1418 "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg), 1419 "r"(__ptid), "r"(__tls), "r"(__ctid), 1420 "i"(__NR_clone), "i"(__NR_exit) 1421 : "x30", "memory"); 1422 return res; 1423 } 1424 #elif defined(__powerpc64__) 1425 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1426 int *parent_tidptr, void *newtls, int *child_tidptr) { 1427 long long res; 1428 // Stack frame structure. 1429 #if SANITIZER_PPC64V1 1430 // Back chain == 0 (SP + 112) 1431 // Frame (112 bytes): 1432 // Parameter save area (SP + 48), 8 doublewords 1433 // TOC save area (SP + 40) 1434 // Link editor doubleword (SP + 32) 1435 // Compiler doubleword (SP + 24) 1436 // LR save area (SP + 16) 1437 // CR save area (SP + 8) 1438 // Back chain (SP + 0) 1439 # define FRAME_SIZE 112 1440 # define FRAME_TOC_SAVE_OFFSET 40 1441 #elif SANITIZER_PPC64V2 1442 // Back chain == 0 (SP + 32) 1443 // Frame (32 bytes): 1444 // TOC save area (SP + 24) 1445 // LR save area (SP + 16) 1446 // CR save area (SP + 8) 1447 // Back chain (SP + 0) 1448 # define FRAME_SIZE 32 1449 # define FRAME_TOC_SAVE_OFFSET 24 1450 #else 1451 # error "Unsupported PPC64 ABI" 1452 #endif 1453 if (!fn || !child_stack) 1454 return -EINVAL; 1455 CHECK_EQ(0, (uptr)child_stack % 16); 1456 1457 register int (*__fn)(void *) __asm__("r3") = fn; 1458 register void *__cstack __asm__("r4") = child_stack; 1459 register int __flags __asm__("r5") = flags; 1460 register void *__arg __asm__("r6") = arg; 1461 register int *__ptidptr __asm__("r7") = parent_tidptr; 1462 register void *__newtls __asm__("r8") = newtls; 1463 register int *__ctidptr __asm__("r9") = child_tidptr; 1464 1465 __asm__ __volatile__( 1466 /* fn and arg are saved across the syscall */ 1467 "mr 28, %5\n\t" 1468 "mr 27, %8\n\t" 1469 1470 /* syscall 1471 r0 == __NR_clone 1472 r3 == flags 1473 r4 == child_stack 1474 r5 == parent_tidptr 1475 r6 == newtls 1476 r7 == child_tidptr */ 1477 "mr 3, %7\n\t" 1478 "mr 5, %9\n\t" 1479 "mr 6, %10\n\t" 1480 "mr 7, %11\n\t" 1481 "li 0, %3\n\t" 1482 "sc\n\t" 1483 1484 /* Test if syscall was successful */ 1485 "cmpdi cr1, 3, 0\n\t" 1486 "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t" 1487 "bne- cr1, 1f\n\t" 1488 1489 /* Set up stack frame */ 1490 "li 29, 0\n\t" 1491 "stdu 29, -8(1)\n\t" 1492 "stdu 1, -%12(1)\n\t" 1493 /* Do the function call */ 1494 "std 2, %13(1)\n\t" 1495 #if SANITIZER_PPC64V1 1496 "ld 0, 0(28)\n\t" 1497 "ld 2, 8(28)\n\t" 1498 "mtctr 0\n\t" 1499 #elif SANITIZER_PPC64V2 1500 "mr 12, 28\n\t" 1501 "mtctr 12\n\t" 1502 #else 1503 # error "Unsupported PPC64 ABI" 1504 #endif 1505 "mr 3, 27\n\t" 1506 "bctrl\n\t" 1507 "ld 2, %13(1)\n\t" 1508 1509 /* Call _exit(r3) */ 1510 "li 0, %4\n\t" 1511 "sc\n\t" 1512 1513 /* Return to parent */ 1514 "1:\n\t" 1515 "mr %0, 3\n\t" 1516 : "=r" (res) 1517 : "0" (-1), 1518 "i" (EINVAL), 1519 "i" (__NR_clone), 1520 "i" (__NR_exit), 1521 "r" (__fn), 1522 "r" (__cstack), 1523 "r" (__flags), 1524 "r" (__arg), 1525 "r" (__ptidptr), 1526 "r" (__newtls), 1527 "r" (__ctidptr), 1528 "i" (FRAME_SIZE), 1529 "i" (FRAME_TOC_SAVE_OFFSET) 1530 : "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29"); 1531 return res; 1532 } 1533 #elif defined(__i386__) && SANITIZER_LINUX 1534 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1535 int *parent_tidptr, void *newtls, int *child_tidptr) { 1536 int res; 1537 if (!fn || !child_stack) 1538 return -EINVAL; 1539 CHECK_EQ(0, (uptr)child_stack % 16); 1540 child_stack = (char *)child_stack - 7 * sizeof(unsigned int); 1541 ((unsigned int *)child_stack)[0] = (uptr)flags; 1542 ((unsigned int *)child_stack)[1] = (uptr)0; 1543 ((unsigned int *)child_stack)[2] = (uptr)fn; 1544 ((unsigned int *)child_stack)[3] = (uptr)arg; 1545 __asm__ __volatile__( 1546 /* %eax = syscall(%eax = SYSCALL(clone), 1547 * %ebx = flags, 1548 * %ecx = child_stack, 1549 * %edx = parent_tidptr, 1550 * %esi = new_tls, 1551 * %edi = child_tidptr) 1552 */ 1553 1554 /* Obtain flags */ 1555 "movl (%%ecx), %%ebx\n" 1556 /* Do the system call */ 1557 "pushl %%ebx\n" 1558 "pushl %%esi\n" 1559 "pushl %%edi\n" 1560 /* Remember the flag value. */ 1561 "movl %%ebx, (%%ecx)\n" 1562 "int $0x80\n" 1563 "popl %%edi\n" 1564 "popl %%esi\n" 1565 "popl %%ebx\n" 1566 1567 /* if (%eax != 0) 1568 * return; 1569 */ 1570 1571 "test %%eax,%%eax\n" 1572 "jnz 1f\n" 1573 1574 /* terminate the stack frame */ 1575 "xorl %%ebp,%%ebp\n" 1576 /* Call FN. */ 1577 "call *%%ebx\n" 1578 #ifdef PIC 1579 "call here\n" 1580 "here:\n" 1581 "popl %%ebx\n" 1582 "addl $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n" 1583 #endif 1584 /* Call exit */ 1585 "movl %%eax, %%ebx\n" 1586 "movl %2, %%eax\n" 1587 "int $0x80\n" 1588 "1:\n" 1589 : "=a" (res) 1590 : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)), 1591 "c"(child_stack), 1592 "d"(parent_tidptr), 1593 "S"(newtls), 1594 "D"(child_tidptr) 1595 : "memory"); 1596 return res; 1597 } 1598 #elif defined(__arm__) && SANITIZER_LINUX 1599 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg, 1600 int *parent_tidptr, void *newtls, int *child_tidptr) { 1601 unsigned int res; 1602 if (!fn || !child_stack) 1603 return -EINVAL; 1604 child_stack = (char *)child_stack - 2 * sizeof(unsigned int); 1605 ((unsigned int *)child_stack)[0] = (uptr)fn; 1606 ((unsigned int *)child_stack)[1] = (uptr)arg; 1607 register int r0 __asm__("r0") = flags; 1608 register void *r1 __asm__("r1") = child_stack; 1609 register int *r2 __asm__("r2") = parent_tidptr; 1610 register void *r3 __asm__("r3") = newtls; 1611 register int *r4 __asm__("r4") = child_tidptr; 1612 register int r7 __asm__("r7") = __NR_clone; 1613 1614 #if __ARM_ARCH > 4 || defined (__ARM_ARCH_4T__) 1615 # define ARCH_HAS_BX 1616 #endif 1617 #if __ARM_ARCH > 4 1618 # define ARCH_HAS_BLX 1619 #endif 1620 1621 #ifdef ARCH_HAS_BX 1622 # ifdef ARCH_HAS_BLX 1623 # define BLX(R) "blx " #R "\n" 1624 # else 1625 # define BLX(R) "mov lr, pc; bx " #R "\n" 1626 # endif 1627 #else 1628 # define BLX(R) "mov lr, pc; mov pc," #R "\n" 1629 #endif 1630 1631 __asm__ __volatile__( 1632 /* %r0 = syscall(%r7 = SYSCALL(clone), 1633 * %r0 = flags, 1634 * %r1 = child_stack, 1635 * %r2 = parent_tidptr, 1636 * %r3 = new_tls, 1637 * %r4 = child_tidptr) 1638 */ 1639 1640 /* Do the system call */ 1641 "swi 0x0\n" 1642 1643 /* if (%r0 != 0) 1644 * return %r0; 1645 */ 1646 "cmp r0, #0\n" 1647 "bne 1f\n" 1648 1649 /* In the child, now. Call "fn(arg)". */ 1650 "ldr r0, [sp, #4]\n" 1651 "ldr ip, [sp], #8\n" 1652 BLX(ip) 1653 /* Call _exit(%r0). */ 1654 "mov r7, %7\n" 1655 "swi 0x0\n" 1656 "1:\n" 1657 "mov %0, r0\n" 1658 : "=r"(res) 1659 : "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7), 1660 "i"(__NR_exit) 1661 : "memory"); 1662 return res; 1663 } 1664 #endif // defined(__x86_64__) && SANITIZER_LINUX 1665 1666 #if SANITIZER_LINUX 1667 int internal_uname(struct utsname *buf) { 1668 return internal_syscall(SYSCALL(uname), buf); 1669 } 1670 #endif 1671 1672 #if SANITIZER_ANDROID 1673 #if __ANDROID_API__ < 21 1674 extern "C" __attribute__((weak)) int dl_iterate_phdr( 1675 int (*)(struct dl_phdr_info *, size_t, void *), void *); 1676 #endif 1677 1678 static int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size, 1679 void *data) { 1680 // Any name starting with "lib" indicates a bug in L where library base names 1681 // are returned instead of paths. 1682 if (info->dlpi_name && info->dlpi_name[0] == 'l' && 1683 info->dlpi_name[1] == 'i' && info->dlpi_name[2] == 'b') { 1684 *(bool *)data = true; 1685 return 1; 1686 } 1687 return 0; 1688 } 1689 1690 static atomic_uint32_t android_api_level; 1691 1692 static AndroidApiLevel AndroidDetectApiLevelStatic() { 1693 #if __ANDROID_API__ <= 19 1694 return ANDROID_KITKAT; 1695 #elif __ANDROID_API__ <= 22 1696 return ANDROID_LOLLIPOP_MR1; 1697 #else 1698 return ANDROID_POST_LOLLIPOP; 1699 #endif 1700 } 1701 1702 static AndroidApiLevel AndroidDetectApiLevel() { 1703 if (!&dl_iterate_phdr) 1704 return ANDROID_KITKAT; // K or lower 1705 bool base_name_seen = false; 1706 dl_iterate_phdr(dl_iterate_phdr_test_cb, &base_name_seen); 1707 if (base_name_seen) 1708 return ANDROID_LOLLIPOP_MR1; // L MR1 1709 return ANDROID_POST_LOLLIPOP; // post-L 1710 // Plain L (API level 21) is completely broken wrt ASan and not very 1711 // interesting to detect. 1712 } 1713 1714 extern "C" __attribute__((weak)) void* _DYNAMIC; 1715 1716 AndroidApiLevel AndroidGetApiLevel() { 1717 AndroidApiLevel level = 1718 (AndroidApiLevel)atomic_load(&android_api_level, memory_order_relaxed); 1719 if (level) return level; 1720 level = &_DYNAMIC == nullptr ? AndroidDetectApiLevelStatic() 1721 : AndroidDetectApiLevel(); 1722 atomic_store(&android_api_level, level, memory_order_relaxed); 1723 return level; 1724 } 1725 1726 #endif 1727 1728 static HandleSignalMode GetHandleSignalModeImpl(int signum) { 1729 switch (signum) { 1730 case SIGABRT: 1731 return common_flags()->handle_abort; 1732 case SIGILL: 1733 return common_flags()->handle_sigill; 1734 case SIGTRAP: 1735 return common_flags()->handle_sigtrap; 1736 case SIGFPE: 1737 return common_flags()->handle_sigfpe; 1738 case SIGSEGV: 1739 return common_flags()->handle_segv; 1740 case SIGBUS: 1741 return common_flags()->handle_sigbus; 1742 } 1743 return kHandleSignalNo; 1744 } 1745 1746 HandleSignalMode GetHandleSignalMode(int signum) { 1747 HandleSignalMode result = GetHandleSignalModeImpl(signum); 1748 if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler) 1749 return kHandleSignalExclusive; 1750 return result; 1751 } 1752 1753 #if !SANITIZER_GO 1754 void *internal_start_thread(void *(*func)(void *arg), void *arg) { 1755 // Start the thread with signals blocked, otherwise it can steal user signals. 1756 __sanitizer_sigset_t set, old; 1757 internal_sigfillset(&set); 1758 #if SANITIZER_LINUX && !SANITIZER_ANDROID 1759 // Glibc uses SIGSETXID signal during setuid call. If this signal is blocked 1760 // on any thread, setuid call hangs (see test/tsan/setuid.c). 1761 internal_sigdelset(&set, 33); 1762 #endif 1763 internal_sigprocmask(SIG_SETMASK, &set, &old); 1764 void *th; 1765 real_pthread_create(&th, nullptr, func, arg); 1766 internal_sigprocmask(SIG_SETMASK, &old, nullptr); 1767 return th; 1768 } 1769 1770 void internal_join_thread(void *th) { 1771 real_pthread_join(th, nullptr); 1772 } 1773 #else 1774 void *internal_start_thread(void *(*func)(void *), void *arg) { return 0; } 1775 1776 void internal_join_thread(void *th) {} 1777 #endif 1778 1779 #if defined(__aarch64__) 1780 // Android headers in the older NDK releases miss this definition. 1781 struct __sanitizer_esr_context { 1782 struct _aarch64_ctx head; 1783 uint64_t esr; 1784 }; 1785 1786 static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) { 1787 static const u32 kEsrMagic = 0x45535201; 1788 u8 *aux = ucontext->uc_mcontext.__reserved; 1789 while (true) { 1790 _aarch64_ctx *ctx = (_aarch64_ctx *)aux; 1791 if (ctx->size == 0) break; 1792 if (ctx->magic == kEsrMagic) { 1793 *esr = ((__sanitizer_esr_context *)ctx)->esr; 1794 return true; 1795 } 1796 aux += ctx->size; 1797 } 1798 return false; 1799 } 1800 #endif 1801 1802 using Context = ucontext_t; 1803 1804 SignalContext::WriteFlag SignalContext::GetWriteFlag() const { 1805 Context *ucontext = (Context *)context; 1806 #if defined(__x86_64__) || defined(__i386__) 1807 static const uptr PF_WRITE = 1U << 1; 1808 #if SANITIZER_FREEBSD 1809 uptr err = ucontext->uc_mcontext.mc_err; 1810 #elif SANITIZER_NETBSD 1811 uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR]; 1812 #elif SANITIZER_SOLARIS && defined(__i386__) 1813 const int Err = 13; 1814 uptr err = ucontext->uc_mcontext.gregs[Err]; 1815 #else 1816 uptr err = ucontext->uc_mcontext.gregs[REG_ERR]; 1817 #endif // SANITIZER_FREEBSD 1818 return err & PF_WRITE ? WRITE : READ; 1819 #elif defined(__mips__) 1820 uint32_t *exception_source; 1821 uint32_t faulty_instruction; 1822 uint32_t op_code; 1823 1824 exception_source = (uint32_t *)ucontext->uc_mcontext.pc; 1825 faulty_instruction = (uint32_t)(*exception_source); 1826 1827 op_code = (faulty_instruction >> 26) & 0x3f; 1828 1829 // FIXME: Add support for FPU, microMIPS, DSP, MSA memory instructions. 1830 switch (op_code) { 1831 case 0x28: // sb 1832 case 0x29: // sh 1833 case 0x2b: // sw 1834 case 0x3f: // sd 1835 #if __mips_isa_rev < 6 1836 case 0x2c: // sdl 1837 case 0x2d: // sdr 1838 case 0x2a: // swl 1839 case 0x2e: // swr 1840 #endif 1841 return SignalContext::WRITE; 1842 1843 case 0x20: // lb 1844 case 0x24: // lbu 1845 case 0x21: // lh 1846 case 0x25: // lhu 1847 case 0x23: // lw 1848 case 0x27: // lwu 1849 case 0x37: // ld 1850 #if __mips_isa_rev < 6 1851 case 0x1a: // ldl 1852 case 0x1b: // ldr 1853 case 0x22: // lwl 1854 case 0x26: // lwr 1855 #endif 1856 return SignalContext::READ; 1857 #if __mips_isa_rev == 6 1858 case 0x3b: // pcrel 1859 op_code = (faulty_instruction >> 19) & 0x3; 1860 switch (op_code) { 1861 case 0x1: // lwpc 1862 case 0x2: // lwupc 1863 return SignalContext::READ; 1864 } 1865 #endif 1866 } 1867 return SignalContext::UNKNOWN; 1868 #elif defined(__arm__) 1869 static const uptr FSR_WRITE = 1U << 11; 1870 uptr fsr = ucontext->uc_mcontext.error_code; 1871 return fsr & FSR_WRITE ? WRITE : READ; 1872 #elif defined(__aarch64__) 1873 static const u64 ESR_ELx_WNR = 1U << 6; 1874 u64 esr; 1875 if (!Aarch64GetESR(ucontext, &esr)) return UNKNOWN; 1876 return esr & ESR_ELx_WNR ? WRITE : READ; 1877 #elif defined(__sparc__) 1878 // Decode the instruction to determine the access type. 1879 // From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype). 1880 #if SANITIZER_SOLARIS 1881 uptr pc = ucontext->uc_mcontext.gregs[REG_PC]; 1882 #else 1883 // Historical BSDism here. 1884 struct sigcontext *scontext = (struct sigcontext *)context; 1885 #if defined(__arch64__) 1886 uptr pc = scontext->sigc_regs.tpc; 1887 #else 1888 uptr pc = scontext->si_regs.pc; 1889 #endif 1890 #endif 1891 u32 instr = *(u32 *)pc; 1892 return (instr >> 21) & 1 ? WRITE: READ; 1893 #elif defined(__riscv) 1894 unsigned long pc = ucontext->uc_mcontext.__gregs[REG_PC]; 1895 unsigned faulty_instruction = *(uint16_t *)pc; 1896 1897 #if defined(__riscv_compressed) 1898 if ((faulty_instruction & 0x3) != 0x3) { // it's a compressed instruction 1899 // set op_bits to the instruction bits [1, 0, 15, 14, 13] 1900 unsigned op_bits = 1901 ((faulty_instruction & 0x3) << 3) | (faulty_instruction >> 13); 1902 unsigned rd = faulty_instruction & 0xF80; // bits 7-11, inclusive 1903 switch (op_bits) { 1904 case 0b10'010: // c.lwsp (rd != x0) 1905 #if __riscv_xlen == 64 1906 case 0b10'011: // c.ldsp (rd != x0) 1907 #endif 1908 return rd ? SignalContext::READ : SignalContext::UNKNOWN; 1909 case 0b00'010: // c.lw 1910 #if __riscv_flen >= 32 && __riscv_xlen == 32 1911 case 0b10'011: // c.flwsp 1912 #endif 1913 #if __riscv_flen >= 32 || __riscv_xlen == 64 1914 case 0b00'011: // c.flw / c.ld 1915 #endif 1916 #if __riscv_flen == 64 1917 case 0b00'001: // c.fld 1918 case 0b10'001: // c.fldsp 1919 #endif 1920 return SignalContext::READ; 1921 case 0b00'110: // c.sw 1922 case 0b10'110: // c.swsp 1923 #if __riscv_flen >= 32 || __riscv_xlen == 64 1924 case 0b00'111: // c.fsw / c.sd 1925 case 0b10'111: // c.fswsp / c.sdsp 1926 #endif 1927 #if __riscv_flen == 64 1928 case 0b00'101: // c.fsd 1929 case 0b10'101: // c.fsdsp 1930 #endif 1931 return SignalContext::WRITE; 1932 default: 1933 return SignalContext::UNKNOWN; 1934 } 1935 } 1936 #endif 1937 1938 unsigned opcode = faulty_instruction & 0x7f; // lower 7 bits 1939 unsigned funct3 = (faulty_instruction >> 12) & 0x7; // bits 12-14, inclusive 1940 switch (opcode) { 1941 case 0b0000011: // loads 1942 switch (funct3) { 1943 case 0b000: // lb 1944 case 0b001: // lh 1945 case 0b010: // lw 1946 #if __riscv_xlen == 64 1947 case 0b011: // ld 1948 #endif 1949 case 0b100: // lbu 1950 case 0b101: // lhu 1951 return SignalContext::READ; 1952 default: 1953 return SignalContext::UNKNOWN; 1954 } 1955 case 0b0100011: // stores 1956 switch (funct3) { 1957 case 0b000: // sb 1958 case 0b001: // sh 1959 case 0b010: // sw 1960 #if __riscv_xlen == 64 1961 case 0b011: // sd 1962 #endif 1963 return SignalContext::WRITE; 1964 default: 1965 return SignalContext::UNKNOWN; 1966 } 1967 #if __riscv_flen >= 32 1968 case 0b0000111: // floating-point loads 1969 switch (funct3) { 1970 case 0b010: // flw 1971 #if __riscv_flen == 64 1972 case 0b011: // fld 1973 #endif 1974 return SignalContext::READ; 1975 default: 1976 return SignalContext::UNKNOWN; 1977 } 1978 case 0b0100111: // floating-point stores 1979 switch (funct3) { 1980 case 0b010: // fsw 1981 #if __riscv_flen == 64 1982 case 0b011: // fsd 1983 #endif 1984 return SignalContext::WRITE; 1985 default: 1986 return SignalContext::UNKNOWN; 1987 } 1988 #endif 1989 default: 1990 return SignalContext::UNKNOWN; 1991 } 1992 #else 1993 (void)ucontext; 1994 return UNKNOWN; // FIXME: Implement. 1995 #endif 1996 } 1997 1998 bool SignalContext::IsTrueFaultingAddress() const { 1999 auto si = static_cast<const siginfo_t *>(siginfo); 2000 // SIGSEGV signals without a true fault address have si_code set to 128. 2001 return si->si_signo == SIGSEGV && si->si_code != 128; 2002 } 2003 2004 void SignalContext::DumpAllRegisters(void *context) { 2005 // FIXME: Implement this. 2006 } 2007 2008 static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) { 2009 #if SANITIZER_NETBSD 2010 // This covers all NetBSD architectures 2011 ucontext_t *ucontext = (ucontext_t *)context; 2012 *pc = _UC_MACHINE_PC(ucontext); 2013 *bp = _UC_MACHINE_FP(ucontext); 2014 *sp = _UC_MACHINE_SP(ucontext); 2015 #elif defined(__arm__) 2016 ucontext_t *ucontext = (ucontext_t*)context; 2017 *pc = ucontext->uc_mcontext.arm_pc; 2018 *bp = ucontext->uc_mcontext.arm_fp; 2019 *sp = ucontext->uc_mcontext.arm_sp; 2020 #elif defined(__aarch64__) 2021 ucontext_t *ucontext = (ucontext_t*)context; 2022 *pc = ucontext->uc_mcontext.pc; 2023 *bp = ucontext->uc_mcontext.regs[29]; 2024 *sp = ucontext->uc_mcontext.sp; 2025 #elif defined(__hppa__) 2026 ucontext_t *ucontext = (ucontext_t*)context; 2027 *pc = ucontext->uc_mcontext.sc_iaoq[0]; 2028 /* GCC uses %r3 whenever a frame pointer is needed. */ 2029 *bp = ucontext->uc_mcontext.sc_gr[3]; 2030 *sp = ucontext->uc_mcontext.sc_gr[30]; 2031 #elif defined(__x86_64__) 2032 # if SANITIZER_FREEBSD 2033 ucontext_t *ucontext = (ucontext_t*)context; 2034 *pc = ucontext->uc_mcontext.mc_rip; 2035 *bp = ucontext->uc_mcontext.mc_rbp; 2036 *sp = ucontext->uc_mcontext.mc_rsp; 2037 # else 2038 ucontext_t *ucontext = (ucontext_t*)context; 2039 *pc = ucontext->uc_mcontext.gregs[REG_RIP]; 2040 *bp = ucontext->uc_mcontext.gregs[REG_RBP]; 2041 *sp = ucontext->uc_mcontext.gregs[REG_RSP]; 2042 # endif 2043 #elif defined(__i386__) 2044 # if SANITIZER_FREEBSD 2045 ucontext_t *ucontext = (ucontext_t*)context; 2046 *pc = ucontext->uc_mcontext.mc_eip; 2047 *bp = ucontext->uc_mcontext.mc_ebp; 2048 *sp = ucontext->uc_mcontext.mc_esp; 2049 # else 2050 ucontext_t *ucontext = (ucontext_t*)context; 2051 # if SANITIZER_SOLARIS 2052 /* Use the numeric values: the symbolic ones are undefined by llvm 2053 include/llvm/Support/Solaris.h. */ 2054 # ifndef REG_EIP 2055 # define REG_EIP 14 // REG_PC 2056 # endif 2057 # ifndef REG_EBP 2058 # define REG_EBP 6 // REG_FP 2059 # endif 2060 # ifndef REG_UESP 2061 # define REG_UESP 17 // REG_SP 2062 # endif 2063 # endif 2064 *pc = ucontext->uc_mcontext.gregs[REG_EIP]; 2065 *bp = ucontext->uc_mcontext.gregs[REG_EBP]; 2066 *sp = ucontext->uc_mcontext.gregs[REG_UESP]; 2067 # endif 2068 #elif defined(__powerpc__) || defined(__powerpc64__) 2069 ucontext_t *ucontext = (ucontext_t*)context; 2070 *pc = ucontext->uc_mcontext.regs->nip; 2071 *sp = ucontext->uc_mcontext.regs->gpr[PT_R1]; 2072 // The powerpc{,64}-linux ABIs do not specify r31 as the frame 2073 // pointer, but GCC always uses r31 when we need a frame pointer. 2074 *bp = ucontext->uc_mcontext.regs->gpr[PT_R31]; 2075 #elif defined(__sparc__) 2076 #if defined(__arch64__) || defined(__sparcv9) 2077 #define STACK_BIAS 2047 2078 #else 2079 #define STACK_BIAS 0 2080 # endif 2081 # if SANITIZER_SOLARIS 2082 ucontext_t *ucontext = (ucontext_t *)context; 2083 *pc = ucontext->uc_mcontext.gregs[REG_PC]; 2084 *sp = ucontext->uc_mcontext.gregs[REG_O6] + STACK_BIAS; 2085 #else 2086 // Historical BSDism here. 2087 struct sigcontext *scontext = (struct sigcontext *)context; 2088 #if defined(__arch64__) 2089 *pc = scontext->sigc_regs.tpc; 2090 *sp = scontext->sigc_regs.u_regs[14] + STACK_BIAS; 2091 #else 2092 *pc = scontext->si_regs.pc; 2093 *sp = scontext->si_regs.u_regs[14]; 2094 #endif 2095 # endif 2096 *bp = (uptr)((uhwptr *)*sp)[14] + STACK_BIAS; 2097 #elif defined(__mips__) 2098 ucontext_t *ucontext = (ucontext_t*)context; 2099 *pc = ucontext->uc_mcontext.pc; 2100 *bp = ucontext->uc_mcontext.gregs[30]; 2101 *sp = ucontext->uc_mcontext.gregs[29]; 2102 #elif defined(__s390__) 2103 ucontext_t *ucontext = (ucontext_t*)context; 2104 # if defined(__s390x__) 2105 *pc = ucontext->uc_mcontext.psw.addr; 2106 # else 2107 *pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff; 2108 # endif 2109 *bp = ucontext->uc_mcontext.gregs[11]; 2110 *sp = ucontext->uc_mcontext.gregs[15]; 2111 #elif defined(__riscv) 2112 ucontext_t *ucontext = (ucontext_t*)context; 2113 *pc = ucontext->uc_mcontext.__gregs[REG_PC]; 2114 *bp = ucontext->uc_mcontext.__gregs[REG_S0]; 2115 *sp = ucontext->uc_mcontext.__gregs[REG_SP]; 2116 #else 2117 # error "Unsupported arch" 2118 #endif 2119 } 2120 2121 void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); } 2122 2123 void InitializePlatformEarly() { 2124 // Do nothing. 2125 } 2126 2127 void MaybeReexec() { 2128 // No need to re-exec on Linux. 2129 } 2130 2131 void CheckASLR() { 2132 #if SANITIZER_NETBSD 2133 int mib[3]; 2134 int paxflags; 2135 uptr len = sizeof(paxflags); 2136 2137 mib[0] = CTL_PROC; 2138 mib[1] = internal_getpid(); 2139 mib[2] = PROC_PID_PAXFLAGS; 2140 2141 if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) { 2142 Printf("sysctl failed\n"); 2143 Die(); 2144 } 2145 2146 if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_ASLR)) { 2147 Printf("This sanitizer is not compatible with enabled ASLR.\n" 2148 "To disable ASLR, please run \"paxctl +a %s\" and try again.\n", 2149 GetArgv()[0]); 2150 Die(); 2151 } 2152 #elif SANITIZER_PPC64V2 2153 // Disable ASLR for Linux PPC64LE. 2154 int old_personality = personality(0xffffffff); 2155 if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) { 2156 VReport(1, "WARNING: Program is being run with address space layout " 2157 "randomization (ASLR) enabled which prevents the thread and " 2158 "memory sanitizers from working on powerpc64le.\n" 2159 "ASLR will be disabled and the program re-executed.\n"); 2160 CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1); 2161 ReExec(); 2162 } 2163 #elif SANITIZER_FREEBSD 2164 int aslr_pie; 2165 uptr len = sizeof(aslr_pie); 2166 #if SANITIZER_WORDSIZE == 64 2167 if (UNLIKELY(internal_sysctlbyname("kern.elf64.aslr.pie_enable", 2168 &aslr_pie, &len, NULL, 0) == -1)) { 2169 // We're making things less 'dramatic' here since 2170 // the OID is not necessarily guaranteed to be here 2171 // just yet regarding FreeBSD release 2172 return; 2173 } 2174 2175 if (aslr_pie > 0) { 2176 Printf("This sanitizer is not compatible with enabled ASLR " 2177 "and binaries compiled with PIE\n"); 2178 Die(); 2179 } 2180 #endif 2181 // there might be 32 bits compat for 64 bits 2182 if (UNLIKELY(internal_sysctlbyname("kern.elf32.aslr.pie_enable", 2183 &aslr_pie, &len, NULL, 0) == -1)) { 2184 return; 2185 } 2186 2187 if (aslr_pie > 0) { 2188 Printf("This sanitizer is not compatible with enabled ASLR " 2189 "and binaries compiled with PIE\n"); 2190 Die(); 2191 } 2192 #else 2193 // Do nothing 2194 #endif 2195 } 2196 2197 void CheckMPROTECT() { 2198 #if SANITIZER_NETBSD 2199 int mib[3]; 2200 int paxflags; 2201 uptr len = sizeof(paxflags); 2202 2203 mib[0] = CTL_PROC; 2204 mib[1] = internal_getpid(); 2205 mib[2] = PROC_PID_PAXFLAGS; 2206 2207 if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) { 2208 Printf("sysctl failed\n"); 2209 Die(); 2210 } 2211 2212 if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_MPROTECT)) { 2213 Printf("This sanitizer is not compatible with enabled MPROTECT\n"); 2214 Die(); 2215 } 2216 #else 2217 // Do nothing 2218 #endif 2219 } 2220 2221 void PrintModuleMap() { } 2222 2223 void CheckNoDeepBind(const char *filename, int flag) { 2224 #ifdef RTLD_DEEPBIND 2225 if (flag & RTLD_DEEPBIND) { 2226 Report( 2227 "You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag" 2228 " which is incompatible with sanitizer runtime " 2229 "(see https://github.com/google/sanitizers/issues/611 for details" 2230 "). If you want to run %s library under sanitizers please remove " 2231 "RTLD_DEEPBIND from dlopen flags.\n", 2232 filename, filename); 2233 Die(); 2234 } 2235 #endif 2236 } 2237 2238 uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding, 2239 uptr *largest_gap_found, 2240 uptr *max_occupied_addr) { 2241 UNREACHABLE("FindAvailableMemoryRange is not available"); 2242 return 0; 2243 } 2244 2245 bool GetRandom(void *buffer, uptr length, bool blocking) { 2246 if (!buffer || !length || length > 256) 2247 return false; 2248 #if SANITIZER_USE_GETENTROPY 2249 uptr rnd = getentropy(buffer, length); 2250 int rverrno = 0; 2251 if (internal_iserror(rnd, &rverrno) && rverrno == EFAULT) 2252 return false; 2253 else if (rnd == 0) 2254 return true; 2255 #endif // SANITIZER_USE_GETENTROPY 2256 2257 #if SANITIZER_USE_GETRANDOM 2258 static atomic_uint8_t skip_getrandom_syscall; 2259 if (!atomic_load_relaxed(&skip_getrandom_syscall)) { 2260 // Up to 256 bytes, getrandom will not be interrupted. 2261 uptr res = internal_syscall(SYSCALL(getrandom), buffer, length, 2262 blocking ? 0 : GRND_NONBLOCK); 2263 int rverrno = 0; 2264 if (internal_iserror(res, &rverrno) && rverrno == ENOSYS) 2265 atomic_store_relaxed(&skip_getrandom_syscall, 1); 2266 else if (res == length) 2267 return true; 2268 } 2269 #endif // SANITIZER_USE_GETRANDOM 2270 // Up to 256 bytes, a read off /dev/urandom will not be interrupted. 2271 // blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom. 2272 uptr fd = internal_open("/dev/urandom", O_RDONLY); 2273 if (internal_iserror(fd)) 2274 return false; 2275 uptr res = internal_read(fd, buffer, length); 2276 if (internal_iserror(res)) 2277 return false; 2278 internal_close(fd); 2279 return true; 2280 } 2281 2282 } // namespace __sanitizer 2283 2284 #endif 2285