libsanitizer/sanitizer_common/sanitizer_linux.cc

   1 //===-- sanitizer_linux.cc ------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is shared between AddressSanitizer and ThreadSanitizer
   9 // run-time libraries and implements linux-specific functions from
  10 // sanitizer_libc.h.
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_platform.h"
  14
  15 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
  16     SANITIZER_OPENBSD || SANITIZER_SOLARIS
  17
  18 #include "sanitizer_common.h"
  19 #include "sanitizer_flags.h"
  20 #include "sanitizer_getauxval.h"
  21 #include "sanitizer_internal_defs.h"
  22 #include "sanitizer_libc.h"
  23 #include "sanitizer_linux.h"
  24 #include "sanitizer_mutex.h"
  25 #include "sanitizer_placement_new.h"
  26 #include "sanitizer_procmaps.h"
  27
  28 #if SANITIZER_LINUX
  29 #include <asm/param.h>
  30 #endif
  31
  32 // For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat'
  33 // format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To
  34 // access stat from asm/stat.h, without conflicting with definition in
  35 // sys/stat.h, we use this trick.
  36 #if defined(__mips64)
  37 #include <asm/unistd.h>
  38 #include <sys/types.h>
  39 #define stat kernel_stat
  40 #include <asm/stat.h>
  41 #undef stat
  42 #endif
  43
  44 #include <dlfcn.h>
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <link.h>
  48 #include <pthread.h>
  49 #include <sched.h>
  50 #include <signal.h>
  51 #include <sys/mman.h>
  52 #include <sys/param.h>
  53 #if !SANITIZER_SOLARIS
  54 #include <sys/ptrace.h>
  55 #endif
  56 #include <sys/resource.h>
  57 #include <sys/stat.h>
  58 #include <sys/syscall.h>
  59 #include <sys/time.h>
  60 #include <sys/types.h>
  61 #if !SANITIZER_OPENBSD
  62 #include <ucontext.h>
  63 #endif
  64 #if SANITIZER_OPENBSD
  65 #include <sys/futex.h>
  66 #include <sys/sysctl.h>
  67 #endif
  68 #include <unistd.h>
  69
  70 #if SANITIZER_LINUX
  71 #include <sys/utsname.h>
  72 #endif
  73
  74 #if SANITIZER_LINUX && !SANITIZER_ANDROID
  75 #include <sys/personality.h>
  76 #endif
  77
  78 #if SANITIZER_FREEBSD
  79 #include <sys/exec.h>
  80 #include <sys/sysctl.h>
  81 #include <machine/atomic.h>
  82 extern "C" {
  83 // <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on
  84 // FreeBSD 9.2 and 10.0.
  85 #include <sys/umtx.h>
  86 }
  87 #include <sys/thr.h>
  88 #endif  // SANITIZER_FREEBSD
  89
  90 #if SANITIZER_NETBSD
  91 #include <limits.h>  // For NAME_MAX
  92 #include <sys/sysctl.h>
  93 #include <sys/exec.h>
  94 extern struct ps_strings *__ps_strings;
  95 #endif  // SANITIZER_NETBSD
  96
  97 #if SANITIZER_SOLARIS
  98 #include <stdlib.h>
  99 #include <thread.h>
 100 #define environ _environ
 101 #endif
 102
 103 extern char **environ;
 104
 105 #if SANITIZER_LINUX
 106 // <linux/time.h>
 107 struct kernel_timeval {
 108   long tv_sec;
 109   long tv_usec;
 110 };
 111
 112 // <linux/futex.h> is broken on some linux distributions.
 113 const int FUTEX_WAIT = 0;
 114 const int FUTEX_WAKE = 1;
 115 const int FUTEX_PRIVATE_FLAG = 128;
 116 const int FUTEX_WAIT_PRIVATE = FUTEX_WAIT | FUTEX_PRIVATE_FLAG;
 117 const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG;
 118 #endif  // SANITIZER_LINUX
 119
 120 // Are we using 32-bit or 64-bit Linux syscalls?
 121 // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
 122 // but it still needs to use 64-bit syscalls.
 123 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) ||       \
 124                         SANITIZER_WORDSIZE == 64)
 125 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
 126 #else
 127 # define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
 128 #endif
 129
 130 #if defined(__x86_64__) || SANITIZER_MIPS64
 131 extern "C" {
 132 extern void internal_sigreturn();
 133 }
 134 #endif
 135
 136 // Note : FreeBSD had implemented both
 137 // Linux and OpenBSD apis, available from
 138 // future 12.x version most likely
 139 #if SANITIZER_LINUX && defined(__NR_getrandom)
 140 # if !defined(GRND_NONBLOCK)
 141 #  define GRND_NONBLOCK 1
 142 # endif
 143 # define SANITIZER_USE_GETRANDOM 1
 144 #else
 145 # define SANITIZER_USE_GETRANDOM 0
 146 #endif  // SANITIZER_LINUX && defined(__NR_getrandom)
 147
 148 #if SANITIZER_OPENBSD
 149 # define SANITIZER_USE_GETENTROPY 1
 150 #else
 151 # if SANITIZER_FREEBSD && __FreeBSD_version >= 1200000
 152 #   define SANITIZER_USE_GETENTROPY 1
 153 # else
 154 #   define SANITIZER_USE_GETENTROPY 0
 155 # endif
 156 #endif // SANITIZER_USE_GETENTROPY
 157
 158 namespace __sanitizer {
 159
 160 #if SANITIZER_LINUX && defined(__x86_64__)
 161 #include "sanitizer_syscall_linux_x86_64.inc"
 162 #elif SANITIZER_LINUX && defined(__aarch64__)
 163 #include "sanitizer_syscall_linux_aarch64.inc"
 164 #elif SANITIZER_LINUX && defined(__arm__)
 165 #include "sanitizer_syscall_linux_arm.inc"
 166 #else
 167 #include "sanitizer_syscall_generic.inc"
 168 #endif
 169
 170 // --------------- sanitizer_libc.h
 171 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
 172 #if !SANITIZER_S390 && !SANITIZER_OPENBSD
 173 uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
 174                    OFF_T offset) {
 175 #if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
 176   return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd,
 177                           offset);
 178 #else
 179   // mmap2 specifies file offset in 4096-byte units.
 180   CHECK(IsAligned(offset, 4096));
 181   return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd,
 182                           offset / 4096);
 183 #endif
 184 }
 185 #endif // !SANITIZER_S390 && !SANITIZER_OPENBSD
 186
 187 #if !SANITIZER_OPENBSD
 188 uptr internal_munmap(void *addr, uptr length) {
 189   return internal_syscall(SYSCALL(munmap), (uptr)addr, length);
 190 }
 191
 192 int internal_mprotect(void *addr, uptr length, int prot) {
 193   return internal_syscall(SYSCALL(mprotect), (uptr)addr, length, prot);
 194 }
 195 #endif
 196
 197 uptr internal_close(fd_t fd) {
 198   return internal_syscall(SYSCALL(close), fd);
 199 }
 200
 201 uptr internal_open(const char *filename, int flags) {
 202 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
 203   return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags);
 204 #else
 205   return internal_syscall(SYSCALL(open), (uptr)filename, flags);
 206 #endif
 207 }
 208
 209 uptr internal_open(const char *filename, int flags, u32 mode) {
 210 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
 211   return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags,
 212                           mode);
 213 #else
 214   return internal_syscall(SYSCALL(open), (uptr)filename, flags, mode);
 215 #endif
 216 }
 217
 218 uptr internal_read(fd_t fd, void *buf, uptr count) {
 219   sptr res;
 220   HANDLE_EINTR(res,
 221                (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf, count));
 222   return res;
 223 }
 224
 225 uptr internal_write(fd_t fd, const void *buf, uptr count) {
 226   sptr res;
 227   HANDLE_EINTR(res,
 228                (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf, count));
 229   return res;
 230 }
 231
 232 uptr internal_ftruncate(fd_t fd, uptr size) {
 233   sptr res;
 234   HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd,
 235                (OFF_T)size));
 236   return res;
 237 }
 238
 239 #if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && SANITIZER_LINUX
 240 static void stat64_to_stat(struct stat64 *in, struct stat *out) {
 241   internal_memset(out, 0, sizeof(*out));
 242   out->st_dev = in->st_dev;
 243   out->st_ino = in->st_ino;
 244   out->st_mode = in->st_mode;
 245   out->st_nlink = in->st_nlink;
 246   out->st_uid = in->st_uid;
 247   out->st_gid = in->st_gid;
 248   out->st_rdev = in->st_rdev;
 249   out->st_size = in->st_size;
 250   out->st_blksize = in->st_blksize;
 251   out->st_blocks = in->st_blocks;
 252   out->st_atime = in->st_atime;
 253   out->st_mtime = in->st_mtime;
 254   out->st_ctime = in->st_ctime;
 255 }
 256 #endif
 257
 258 #if defined(__mips64)
 259 // Undefine compatibility macros from <sys/stat.h>
 260 // so that they would not clash with the kernel_stat
 261 // st_[a|m|c]time fields
 262 #undef st_atime
 263 #undef st_mtime
 264 #undef st_ctime
 265 #if defined(SANITIZER_ANDROID)
 266 // Bionic sys/stat.h defines additional macros
 267 // for compatibility with the old NDKs and
 268 // they clash with the kernel_stat structure
 269 // st_[a|m|c]time_nsec fields.
 270 #undef st_atime_nsec
 271 #undef st_mtime_nsec
 272 #undef st_ctime_nsec
 273 #endif
 274 static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) {
 275   internal_memset(out, 0, sizeof(*out));
 276   out->st_dev = in->st_dev;
 277   out->st_ino = in->st_ino;
 278   out->st_mode = in->st_mode;
 279   out->st_nlink = in->st_nlink;
 280   out->st_uid = in->st_uid;
 281   out->st_gid = in->st_gid;
 282   out->st_rdev = in->st_rdev;
 283   out->st_size = in->st_size;
 284   out->st_blksize = in->st_blksize;
 285   out->st_blocks = in->st_blocks;
 286 #if defined(__USE_MISC)     || \
 287     defined(__USE_XOPEN2K8) || \
 288     defined(SANITIZER_ANDROID)
 289   out->st_atim.tv_sec = in->st_atime;
 290   out->st_atim.tv_nsec = in->st_atime_nsec;
 291   out->st_mtim.tv_sec = in->st_mtime;
 292   out->st_mtim.tv_nsec = in->st_mtime_nsec;
 293   out->st_ctim.tv_sec = in->st_ctime;
 294   out->st_ctim.tv_nsec = in->st_ctime_nsec;
 295 #else
 296   out->st_atime = in->st_atime;
 297   out->st_atimensec = in->st_atime_nsec;
 298   out->st_mtime = in->st_mtime;
 299   out->st_mtimensec = in->st_mtime_nsec;
 300   out->st_ctime = in->st_ctime;
 301   out->st_atimensec = in->st_ctime_nsec;
 302 #endif
 303 }
 304 #endif
 305
 306 uptr internal_stat(const char *path, void *buf) {
 307 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
 308   return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0);
 309 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
 310   return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
 311                           0);
 312 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
 313 # if defined(__mips64)
 314   // For mips64, stat syscall fills buffer in the format of kernel_stat
 315   struct kernel_stat kbuf;
 316   int res = internal_syscall(SYSCALL(stat), path, &kbuf);
 317   kernel_stat_to_stat(&kbuf, (struct stat *)buf);
 318   return res;
 319 # else
 320   return internal_syscall(SYSCALL(stat), (uptr)path, (uptr)buf);
 321 # endif
 322 #else
 323   struct stat64 buf64;
 324   int res = internal_syscall(SYSCALL(stat64), path, &buf64);
 325   stat64_to_stat(&buf64, (struct stat *)buf);
 326   return res;
 327 #endif
 328 }
 329
 330 uptr internal_lstat(const char *path, void *buf) {
 331 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
 332   return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf,
 333                           AT_SYMLINK_NOFOLLOW);
 334 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
 335   return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
 336                           AT_SYMLINK_NOFOLLOW);
 337 #elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
 338 # if SANITIZER_MIPS64
 339   // For mips64, lstat syscall fills buffer in the format of kernel_stat
 340   struct kernel_stat kbuf;
 341   int res = internal_syscall(SYSCALL(lstat), path, &kbuf);
 342   kernel_stat_to_stat(&kbuf, (struct stat *)buf);
 343   return res;
 344 # else
 345   return internal_syscall(SYSCALL(lstat), (uptr)path, (uptr)buf);
 346 # endif
 347 #else
 348   struct stat64 buf64;
 349   int res = internal_syscall(SYSCALL(lstat64), path, &buf64);
 350   stat64_to_stat(&buf64, (struct stat *)buf);
 351   return res;
 352 #endif
 353 }
 354
 355 uptr internal_fstat(fd_t fd, void *buf) {
 356 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD || \
 357     SANITIZER_LINUX_USES_64BIT_SYSCALLS
 358 #if SANITIZER_MIPS64 && !SANITIZER_OPENBSD
 359   // For mips64, fstat syscall fills buffer in the format of kernel_stat
 360   struct kernel_stat kbuf;
 361   int res = internal_syscall(SYSCALL(fstat), fd, &kbuf);
 362   kernel_stat_to_stat(&kbuf, (struct stat *)buf);
 363   return res;
 364 # else
 365   return internal_syscall(SYSCALL(fstat), fd, (uptr)buf);
 366 # endif
 367 #else
 368   struct stat64 buf64;
 369   int res = internal_syscall(SYSCALL(fstat64), fd, &buf64);
 370   stat64_to_stat(&buf64, (struct stat *)buf);
 371   return res;
 372 #endif
 373 }
 374
 375 uptr internal_filesize(fd_t fd) {
 376   struct stat st;
 377   if (internal_fstat(fd, &st))
 378     return -1;
 379   return (uptr)st.st_size;
 380 }
 381
 382 uptr internal_dup2(int oldfd, int newfd) {
 383 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
 384   return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0);
 385 #else
 386   return internal_syscall(SYSCALL(dup2), oldfd, newfd);
 387 #endif
 388 }
 389
 390 uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
 391 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
 392   return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf,
 393                           bufsize);
 394 #elif SANITIZER_OPENBSD
 395   return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf,
 396                           bufsize);
 397 #else
 398   return internal_syscall(SYSCALL(readlink), path, buf, bufsize);
 399 #endif
 400 }
 401
 402 uptr internal_unlink(const char *path) {
 403 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS || SANITIZER_OPENBSD
 404   return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0);
 405 #else
 406   return internal_syscall(SYSCALL(unlink), (uptr)path);
 407 #endif
 408 }
 409
 410 uptr internal_rename(const char *oldpath, const char *newpath) {
 411 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS || SANITIZER_OPENBSD
 412   return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
 413                           (uptr)newpath);
 414 #else
 415   return internal_syscall(SYSCALL(rename), (uptr)oldpath, (uptr)newpath);
 416 #endif
 417 }
 418
 419 uptr internal_sched_yield() {
 420   return internal_syscall(SYSCALL(sched_yield));
 421 }
 422
 423 void internal__exit(int exitcode) {
 424 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
 425   internal_syscall(SYSCALL(exit), exitcode);
 426 #else
 427   internal_syscall(SYSCALL(exit_group), exitcode);
 428 #endif
 429   Die();  // Unreachable.
 430 }
 431
 432 unsigned int internal_sleep(unsigned int seconds) {
 433   struct timespec ts;
 434   ts.tv_sec = 1;
 435   ts.tv_nsec = 0;
 436   int res = internal_syscall(SYSCALL(nanosleep), &ts, &ts);
 437   if (res) return ts.tv_sec;
 438   return 0;
 439 }
 440
 441 uptr internal_execve(const char *filename, char *const argv[],
 442                      char *const envp[]) {
 443   return internal_syscall(SYSCALL(execve), (uptr)filename, (uptr)argv,
 444                           (uptr)envp);
 445 }
 446 #endif  // !SANITIZER_SOLARIS && !SANITIZER_NETBSD
 447
 448 // ----------------- sanitizer_common.h
 449 bool FileExists(const char *filename) {
 450   struct stat st;
 451 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
 452   if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0))
 453 #else
 454   if (internal_stat(filename, &st))
 455 #endif
 456     return false;
 457   // Sanity check: filename is a regular file.
 458   return S_ISREG(st.st_mode);
 459 }
 460
 461 #if !SANITIZER_NETBSD
 462 tid_t GetTid() {
 463 #if SANITIZER_FREEBSD
 464   long Tid;
 465   thr_self(&Tid);
 466   return Tid;
 467 #elif SANITIZER_OPENBSD
 468   return internal_syscall(SYSCALL(getthrid));
 469 #elif SANITIZER_SOLARIS
 470   return thr_self();
 471 #else
 472   return internal_syscall(SYSCALL(gettid));
 473 #endif
 474 }
 475
 476 int TgKill(pid_t pid, tid_t tid, int sig) {
 477 #if SANITIZER_LINUX
 478   return internal_syscall(SYSCALL(tgkill), pid, tid, sig);
 479 #elif SANITIZER_FREEBSD
 480   return internal_syscall(SYSCALL(thr_kill2), pid, tid, sig);
 481 #elif SANITIZER_OPENBSD
 482   (void)pid;
 483   return internal_syscall(SYSCALL(thrkill), tid, sig, nullptr);
 484 #elif SANITIZER_SOLARIS
 485   (void)pid;
 486   return thr_kill(tid, sig);
 487 #endif
 488 }
 489 #endif
 490
 491 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
 492 u64 NanoTime() {
 493 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
 494   timeval tv;
 495 #else
 496   kernel_timeval tv;
 497 #endif
 498   internal_memset(&tv, 0, sizeof(tv));
 499   internal_syscall(SYSCALL(gettimeofday), &tv, 0);
 500   return (u64)tv.tv_sec * 1000*1000*1000 + tv.tv_usec * 1000;
 501 }
 502
 503 uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp) {
 504   return internal_syscall(SYSCALL(clock_gettime), clk_id, tp);
 505 }
 506 #endif  // !SANITIZER_SOLARIS && !SANITIZER_NETBSD
 507
 508 // Like getenv, but reads env directly from /proc (on Linux) or parses the
 509 // 'environ' array (on some others) and does not use libc. This function
 510 // should be called first inside __asan_init.
 511 const char *GetEnv(const char *name) {
 512 #if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD || \
 513     SANITIZER_SOLARIS
 514   if (::environ != 0) {
 515     uptr NameLen = internal_strlen(name);
 516     for (char **Env = ::environ; *Env != 0; Env++) {
 517       if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
 518         return (*Env) + NameLen + 1;
 519     }
 520   }
 521   return 0;  // Not found.
 522 #elif SANITIZER_LINUX
 523   static char *environ;
 524   static uptr len;
 525   static bool inited;
 526   if (!inited) {
 527     inited = true;
 528     uptr environ_size;
 529     if (!ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, &len))
 530       environ = nullptr;
 531   }
 532   if (!environ || len == 0) return nullptr;
 533   uptr namelen = internal_strlen(name);
 534   const char *p = environ;
 535   while (*p != '\0') {  // will happen at the \0\0 that terminates the buffer
 536     // proc file has the format NAME=value\0NAME=value\0NAME=value\0...
 537     const char* endp =
 538         (char*)internal_memchr(p, '\0', len - (p - environ));
 539     if (!endp)  // this entry isn't NUL terminated
 540       return nullptr;
 541     else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=')  // Match.
 542       return p + namelen + 1;  // point after =
 543     p = endp + 1;
 544   }
 545   return nullptr;  // Not found.
 546 #else
 547 #error "Unsupported platform"
 548 #endif
 549 }
 550
 551 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD && !SANITIZER_OPENBSD
 552 extern "C" {
 553 SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end;
 554 }
 555 #endif
 556
 557 #if !SANITIZER_GO && !SANITIZER_FREEBSD && !SANITIZER_NETBSD &&                \
 558     !SANITIZER_OPENBSD
 559 static void ReadNullSepFileToArray(const char *path, char ***arr,
 560                                    int arr_size) {
 561   char *buff;
 562   uptr buff_size;
 563   uptr buff_len;
 564   *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray");
 565   if (!ReadFileToBuffer(path, &buff, &buff_size, &buff_len, 1024 * 1024)) {
 566     (*arr)[0] = nullptr;
 567     return;
 568   }
 569   (*arr)[0] = buff;
 570   int count, i;
 571   for (count = 1, i = 1; ; i++) {
 572     if (buff[i] == 0) {
 573       if (buff[i+1] == 0) break;
 574       (*arr)[count] = &buff[i+1];
 575       CHECK_LE(count, arr_size - 1);  // FIXME: make this more flexible.
 576       count++;
 577     }
 578   }
 579   (*arr)[count] = nullptr;
 580 }
 581 #endif
 582
 583 #if !SANITIZER_OPENBSD
 584 static void GetArgsAndEnv(char ***argv, char ***envp) {
 585 #if SANITIZER_FREEBSD
 586   // On FreeBSD, retrieving the argument and environment arrays is done via the
 587   // kern.ps_strings sysctl, which returns a pointer to a structure containing
 588   // this information. See also <sys/exec.h>.
 589   ps_strings *pss;
 590   uptr sz = sizeof(pss);
 591   if (internal_sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) {
 592     Printf("sysctl kern.ps_strings failed\n");
 593     Die();
 594   }
 595   *argv = pss->ps_argvstr;
 596   *envp = pss->ps_envstr;
 597 #elif SANITIZER_NETBSD
 598   *argv = __ps_strings->ps_argvstr;
 599   *envp = __ps_strings->ps_envstr;
 600 #else // SANITIZER_FREEBSD
 601 #if !SANITIZER_GO
 602   if (&__libc_stack_end) {
 603 #endif // !SANITIZER_GO
 604     uptr* stack_end = (uptr*)__libc_stack_end;
 605     int argc = *stack_end;
 606     *argv = (char**)(stack_end + 1);
 607     *envp = (char**)(stack_end + argc + 2);
 608 #if !SANITIZER_GO
 609   } else {
 610     static const int kMaxArgv = 2000, kMaxEnvp = 2000;
 611     ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv);
 612     ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp);
 613   }
 614 #endif // !SANITIZER_GO
 615 #endif // SANITIZER_FREEBSD
 616 }
 617
 618 char **GetArgv() {
 619   char **argv, **envp;
 620   GetArgsAndEnv(&argv, &envp);
 621   return argv;
 622 }
 623
 624 void ReExec() {
 625   char **argv, **envp;
 626   const char *pathname = "/proc/self/exe";
 627
 628 #if SANITIZER_NETBSD
 629   static const int name[] = {
 630     CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME,
 631   };
 632   char path[400];
 633   uptr len;
 634
 635   len = sizeof(path);
 636   if (internal_sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1)
 637     pathname = path;
 638 #elif SANITIZER_SOLARIS
 639   pathname = getexecname();
 640   CHECK_NE(pathname, NULL);
 641 #endif
 642
 643   GetArgsAndEnv(&argv, &envp);
 644   uptr rv = internal_execve(pathname, argv, envp);
 645   int rverrno;
 646   CHECK_EQ(internal_iserror(rv, &rverrno), true);
 647   Printf("execve failed, errno %d\n", rverrno);
 648   Die();
 649 }
 650 #endif
 651
 652 #if !SANITIZER_SOLARIS
 653 enum MutexState {
 654   MtxUnlocked = 0,
 655   MtxLocked = 1,
 656   MtxSleeping = 2
 657 };
 658
 659 BlockingMutex::BlockingMutex() {
 660   internal_memset(this, 0, sizeof(*this));
 661 }
 662
 663 void BlockingMutex::Lock() {
 664   CHECK_EQ(owner_, 0);
 665   atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
 666   if (atomic_exchange(m, MtxLocked, memory_order_acquire) == MtxUnlocked)
 667     return;
 668   while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked) {
 669 #if SANITIZER_FREEBSD
 670     _umtx_op(m, UMTX_OP_WAIT_UINT, MtxSleeping, 0, 0);
 671 #elif SANITIZER_NETBSD
 672     sched_yield(); /* No userspace futex-like synchronization */
 673 #else
 674     internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAIT_PRIVATE, MtxSleeping,
 675                      0, 0, 0);
 676 #endif
 677   }
 678 }
 679
 680 void BlockingMutex::Unlock() {
 681   atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
 682   u32 v = atomic_exchange(m, MtxUnlocked, memory_order_release);
 683   CHECK_NE(v, MtxUnlocked);
 684   if (v == MtxSleeping) {
 685 #if SANITIZER_FREEBSD
 686     _umtx_op(m, UMTX_OP_WAKE, 1, 0, 0);
 687 #elif SANITIZER_NETBSD
 688                    /* No userspace futex-like synchronization */
 689 #else
 690     internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAKE_PRIVATE, 1, 0, 0, 0);
 691 #endif
 692   }
 693 }
 694
 695 void BlockingMutex::CheckLocked() {
 696   atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
 697   CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed));
 698 }
 699 #endif // !SANITIZER_SOLARIS
 700
 701 // ----------------- sanitizer_linux.h
 702 // The actual size of this structure is specified by d_reclen.
 703 // Note that getdents64 uses a different structure format. We only provide the
 704 // 32-bit syscall here.
 705 #if SANITIZER_NETBSD
 706 // Not used
 707 #elif SANITIZER_OPENBSD
 708 // struct dirent is different for Linux and us. At this moment, we use only
 709 // d_fileno (Linux call this d_ino), d_reclen, and d_name.
 710 struct linux_dirent {
 711   u64 d_ino;  // d_fileno
 712   u16 d_reclen;
 713   u16 d_namlen;  // not used
 714   u8 d_type;     // not used
 715   char d_name[NAME_MAX + 1];
 716 };
 717 #else
 718 struct linux_dirent {
 719 #if SANITIZER_X32 || defined(__aarch64__)
 720   u64 d_ino;
 721   u64 d_off;
 722 #else
 723   unsigned long      d_ino;
 724   unsigned long      d_off;
 725 #endif
 726   unsigned short     d_reclen;
 727 #ifdef __aarch64__
 728   unsigned char      d_type;
 729 #endif
 730   char               d_name[256];
 731 };
 732 #endif
 733
 734 #if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
 735 // Syscall wrappers.
 736 uptr internal_ptrace(int request, int pid, void *addr, void *data) {
 737   return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr,
 738                           (uptr)data);
 739 }
 740
 741 uptr internal_waitpid(int pid, int *status, int options) {
 742   return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options,
 743                           0 /* rusage */);
 744 }
 745
 746 uptr internal_getpid() {
 747   return internal_syscall(SYSCALL(getpid));
 748 }
 749
 750 uptr internal_getppid() {
 751   return internal_syscall(SYSCALL(getppid));
 752 }
 753
 754 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
 755 #if SANITIZER_FREEBSD
 756   return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL);
 757 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
 758   return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count);
 759 #else
 760   return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count);
 761 #endif
 762 }
 763
 764 uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
 765   return internal_syscall(SYSCALL(lseek), fd, offset, whence);
 766 }
 767
 768 #if SANITIZER_LINUX
 769 uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) {
 770   return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5);
 771 }
 772 #endif
 773
 774 uptr internal_sigaltstack(const void *ss, void *oss) {
 775   return internal_syscall(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss);
 776 }
 777
 778 int internal_fork() {
 779 #if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
 780   return internal_syscall(SYSCALL(clone), SIGCHLD, 0);
 781 #else
 782   return internal_syscall(SYSCALL(fork));
 783 #endif
 784 }
 785
 786 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
 787 int internal_sysctl(const int *name, unsigned int namelen, void *oldp,
 788                     uptr *oldlenp, const void *newp, uptr newlen) {
 789 #if SANITIZER_OPENBSD
 790   return sysctl(name, namelen, oldp, (size_t *)oldlenp, (void *)newp,
 791                 (size_t)newlen);
 792 #else
 793   return sysctl(name, namelen, oldp, (size_t *)oldlenp, newp, (size_t)newlen);
 794 #endif
 795 }
 796
 797 #if SANITIZER_FREEBSD
 798 int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp,
 799                           const void *newp, uptr newlen) {
 800   return sysctlbyname(sname, oldp, (size_t *)oldlenp, newp, (size_t)newlen);
 801 }
 802 #endif
 803 #endif
 804
 805 #if SANITIZER_LINUX
 806 #define SA_RESTORER 0x04000000
 807 // Doesn't set sa_restorer if the caller did not set it, so use with caution
 808 //(see below).
 809 int internal_sigaction_norestorer(int signum, const void *act, void *oldact) {
 810   __sanitizer_kernel_sigaction_t k_act, k_oldact;
 811   internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t));
 812   internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t));
 813   const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act;
 814   __sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact;
 815   if (u_act) {
 816     k_act.handler = u_act->handler;
 817     k_act.sigaction = u_act->sigaction;
 818     internal_memcpy(&k_act.sa_mask, &u_act->sa_mask,
 819                     sizeof(__sanitizer_kernel_sigset_t));
 820     // Without SA_RESTORER kernel ignores the calls (probably returns EINVAL).
 821     k_act.sa_flags = u_act->sa_flags | SA_RESTORER;
 822     // FIXME: most often sa_restorer is unset, however the kernel requires it
 823     // to point to a valid signal restorer that calls the rt_sigreturn syscall.
 824     // If sa_restorer passed to the kernel is NULL, the program may crash upon
 825     // signal delivery or fail to unwind the stack in the signal handler.
 826     // libc implementation of sigaction() passes its own restorer to
 827     // rt_sigaction, so we need to do the same (we'll need to reimplement the
 828     // restorers; for x86_64 the restorer address can be obtained from
 829     // oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact).
 830 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
 831     k_act.sa_restorer = u_act->sa_restorer;
 832 #endif
 833   }
 834
 835   uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum,
 836       (uptr)(u_act ? &k_act : nullptr),
 837       (uptr)(u_oldact ? &k_oldact : nullptr),
 838       (uptr)sizeof(__sanitizer_kernel_sigset_t));
 839
 840   if ((result == 0) && u_oldact) {
 841     u_oldact->handler = k_oldact.handler;
 842     u_oldact->sigaction = k_oldact.sigaction;
 843     internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask,
 844                     sizeof(__sanitizer_kernel_sigset_t));
 845     u_oldact->sa_flags = k_oldact.sa_flags;
 846 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
 847     u_oldact->sa_restorer = k_oldact.sa_restorer;
 848 #endif
 849   }
 850   return result;
 851 }
 852
 853 // Invokes sigaction via a raw syscall with a restorer, but does not support
 854 // all platforms yet.
 855 // We disable for Go simply because we have not yet added to buildgo.sh.
 856 #if (defined(__x86_64__) || SANITIZER_MIPS64) && !SANITIZER_GO
 857 int internal_sigaction_syscall(int signum, const void *act, void *oldact) {
 858   if (act == nullptr)
 859     return internal_sigaction_norestorer(signum, act, oldact);
 860   __sanitizer_sigaction u_adjust;
 861   internal_memcpy(&u_adjust, act, sizeof(u_adjust));
 862 #if !SANITIZER_ANDROID || !SANITIZER_MIPS32
 863   if (u_adjust.sa_restorer == nullptr) {
 864     u_adjust.sa_restorer = internal_sigreturn;
 865   }
 866 #endif
 867   return internal_sigaction_norestorer(signum, (const void *)&u_adjust, oldact);
 868 }
 869 #endif  // defined(__x86_64__) && !SANITIZER_GO
 870 #endif  // SANITIZER_LINUX
 871
 872 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
 873                           __sanitizer_sigset_t *oldset) {
 874 #if SANITIZER_FREEBSD || SANITIZER_OPENBSD
 875   return internal_syscall(SYSCALL(sigprocmask), how, set, oldset);
 876 #else
 877   __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
 878   __sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset;
 879   return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how,
 880                           (uptr)&k_set->sig[0], (uptr)&k_oldset->sig[0],
 881                           sizeof(__sanitizer_kernel_sigset_t));
 882 #endif
 883 }
 884
 885 void internal_sigfillset(__sanitizer_sigset_t *set) {
 886   internal_memset(set, 0xff, sizeof(*set));
 887 }
 888
 889 void internal_sigemptyset(__sanitizer_sigset_t *set) {
 890   internal_memset(set, 0, sizeof(*set));
 891 }
 892
 893 #if SANITIZER_LINUX
 894 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
 895   signum -= 1;
 896   CHECK_GE(signum, 0);
 897   CHECK_LT(signum, sizeof(*set) * 8);
 898   __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
 899   const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
 900   const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
 901   k_set->sig[idx] &= ~(1 << bit);
 902 }
 903
 904 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
 905   signum -= 1;
 906   CHECK_GE(signum, 0);
 907   CHECK_LT(signum, sizeof(*set) * 8);
 908   __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
 909   const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
 910   const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
 911   return k_set->sig[idx] & (1 << bit);
 912 }
 913 #elif SANITIZER_FREEBSD
 914 void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
 915   sigset_t *rset = reinterpret_cast<sigset_t *>(set);
 916   sigdelset(rset, signum);
 917 }
 918
 919 bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
 920   sigset_t *rset = reinterpret_cast<sigset_t *>(set);
 921   return sigismember(rset, signum);
 922 }
 923 #endif
 924 #endif // !SANITIZER_SOLARIS
 925
 926 #if !SANITIZER_NETBSD
 927 // ThreadLister implementation.
 928 ThreadLister::ThreadLister(pid_t pid) : pid_(pid), buffer_(4096) {
 929   char task_directory_path[80];
 930   internal_snprintf(task_directory_path, sizeof(task_directory_path),
 931                     "/proc/%d/task/", pid);
 932   descriptor_ = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY);
 933   if (internal_iserror(descriptor_)) {
 934     Report("Can't open /proc/%d/task for reading.\n", pid);
 935   }
 936 }
 937
 938 ThreadLister::Result ThreadLister::ListThreads(
 939     InternalMmapVector<tid_t> *threads) {
 940   if (internal_iserror(descriptor_))
 941     return Error;
 942   internal_lseek(descriptor_, 0, SEEK_SET);
 943   threads->clear();
 944
 945   Result result = Ok;
 946   for (bool first_read = true;; first_read = false) {
 947     // Resize to max capacity if it was downsized by IsAlive.
 948     buffer_.resize(buffer_.capacity());
 949     CHECK_GE(buffer_.size(), 4096);
 950     uptr read = internal_getdents(
 951         descriptor_, (struct linux_dirent *)buffer_.data(), buffer_.size());
 952     if (!read)
 953       return result;
 954     if (internal_iserror(read)) {
 955       Report("Can't read directory entries from /proc/%d/task.\n", pid_);
 956       return Error;
 957     }
 958
 959     for (uptr begin = (uptr)buffer_.data(), end = begin + read; begin < end;) {
 960       struct linux_dirent *entry = (struct linux_dirent *)begin;
 961       begin += entry->d_reclen;
 962       if (entry->d_ino == 1) {
 963         // Inode 1 is for bad blocks and also can be a reason for early return.
 964         // Should be emitted if kernel tried to output terminating thread.
 965         // See proc_task_readdir implementation in Linux.
 966         result = Incomplete;
 967       }
 968       if (entry->d_ino && *entry->d_name >= '0' && *entry->d_name <= '9')
 969         threads->push_back(internal_atoll(entry->d_name));
 970     }
 971
 972     // Now we are going to detect short-read or early EOF. In such cases Linux
 973     // can return inconsistent list with missing alive threads.
 974     // Code will just remember that the list can be incomplete but it will
 975     // continue reads to return as much as possible.
 976     if (!first_read) {
 977       // The first one was a short-read by definition.
 978       result = Incomplete;
 979     } else if (read > buffer_.size() - 1024) {
 980       // Read was close to the buffer size. So double the size and assume the
 981       // worst.
 982       buffer_.resize(buffer_.size() * 2);
 983       result = Incomplete;
 984     } else if (!threads->empty() && !IsAlive(threads->back())) {
 985       // Maybe Linux early returned from read on terminated thread (!pid_alive)
 986       // and failed to restore read position.
 987       // See next_tid and proc_task_instantiate in Linux.
 988       result = Incomplete;
 989     }
 990   }
 991 }
 992
 993 bool ThreadLister::IsAlive(int tid) {
 994   // /proc/%d/task/%d/status uses same call to detect alive threads as
 995   // proc_task_readdir. See task_state implementation in Linux.
 996   char path[80];
 997   internal_snprintf(path, sizeof(path), "/proc/%d/task/%d/status", pid_, tid);
 998   if (!ReadFileToVector(path, &buffer_) || buffer_.empty())
 999     return false;
1000   buffer_.push_back(0);
1001   static const char kPrefix[] = "\nPPid:";
1002   const char *field = internal_strstr(buffer_.data(), kPrefix);
1003   if (!field)
1004     return false;
1005   field += internal_strlen(kPrefix);
1006   return (int)internal_atoll(field) != 0;
1007 }
1008
1009 ThreadLister::~ThreadLister() {
1010   if (!internal_iserror(descriptor_))
1011     internal_close(descriptor_);
1012 }
1013 #endif
1014
1015 #if SANITIZER_WORDSIZE == 32
1016 // Take care of unusable kernel area in top gigabyte.
1017 static uptr GetKernelAreaSize() {
1018 #if SANITIZER_LINUX && !SANITIZER_X32
1019   const uptr gbyte = 1UL << 30;
1020
1021   // Firstly check if there are writable segments
1022   // mapped to top gigabyte (e.g. stack).
1023   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
1024   MemoryMappedSegment segment;
1025   while (proc_maps.Next(&segment)) {
1026     if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0;
1027   }
1028
1029 #if !SANITIZER_ANDROID
1030   // Even if nothing is mapped, top Gb may still be accessible
1031   // if we are running on 64-bit kernel.
1032   // Uname may report misleading results if personality type
1033   // is modified (e.g. under schroot) so check this as well.
1034   struct utsname uname_info;
1035   int pers = personality(0xffffffffUL);
1036   if (!(pers & PER_MASK)
1037       && uname(&uname_info) == 0
1038       && internal_strstr(uname_info.machine, "64"))
1039     return 0;
1040 #endif  // SANITIZER_ANDROID
1041
1042   // Top gigabyte is reserved for kernel.
1043   return gbyte;
1044 #else
1045   return 0;
1046 #endif  // SANITIZER_LINUX && !SANITIZER_X32
1047 }
1048 #endif  // SANITIZER_WORDSIZE == 32
1049
1050 uptr GetMaxVirtualAddress() {
1051 #if (SANITIZER_NETBSD || SANITIZER_OPENBSD) && defined(__x86_64__)
1052   return 0x7f7ffffff000ULL;  // (0x00007f8000000000 - PAGE_SIZE)
1053 #elif SANITIZER_WORDSIZE == 64
1054 # if defined(__powerpc64__) || defined(__aarch64__)
1055   // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
1056   // We somehow need to figure out which one we are using now and choose
1057   // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
1058   // Note that with 'ulimit -s unlimited' the stack is moved away from the top
1059   // of the address space, so simply checking the stack address is not enough.
1060   // This should (does) work for both PowerPC64 Endian modes.
1061   // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
1062   return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
1063 # elif defined(__mips64)
1064   return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
1065 # elif defined(__s390x__)
1066   return (1ULL << 53) - 1;  // 0x001fffffffffffffUL;
1067 # else
1068   return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
1069 # endif
1070 #else  // SANITIZER_WORDSIZE == 32
1071 # if defined(__s390__)
1072   return (1ULL << 31) - 1;  // 0x7fffffff;
1073 # else
1074   return (1ULL << 32) - 1;  // 0xffffffff;
1075 # endif
1076 #endif  // SANITIZER_WORDSIZE
1077 }
1078
1079 uptr GetMaxUserVirtualAddress() {
1080   uptr addr = GetMaxVirtualAddress();
1081 #if SANITIZER_WORDSIZE == 32 && !defined(__s390__)
1082   if (!common_flags()->full_address_space)
1083     addr -= GetKernelAreaSize();
1084   CHECK_LT(reinterpret_cast<uptr>(&addr), addr);
1085 #endif
1086   return addr;
1087 }
1088
1089 uptr GetPageSize() {
1090 // Android post-M sysconf(_SC_PAGESIZE) crashes if called from .preinit_array.
1091 #if SANITIZER_ANDROID
1092   return 4096;
1093 #elif SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__))
1094   return EXEC_PAGESIZE;
1095 #elif SANITIZER_USE_GETAUXVAL
1096   return getauxval(AT_PAGESZ);
1097 #else
1098   return sysconf(_SC_PAGESIZE);  // EXEC_PAGESIZE may not be trustworthy.
1099 #endif
1100 }
1101
1102 #if !SANITIZER_OPENBSD
1103 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
1104 #if SANITIZER_SOLARIS
1105   const char *default_module_name = getexecname();
1106   CHECK_NE(default_module_name, NULL);
1107   return internal_snprintf(buf, buf_len, "%s", default_module_name);
1108 #else
1109 #if SANITIZER_FREEBSD || SANITIZER_NETBSD
1110 #if SANITIZER_FREEBSD
1111   const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
1112 #else
1113   const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
1114 #endif
1115   const char *default_module_name = "kern.proc.pathname";
1116   uptr Size = buf_len;
1117   bool IsErr =
1118       (internal_sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0);
1119   int readlink_error = IsErr ? errno : 0;
1120   uptr module_name_len = Size;
1121 #else
1122   const char *default_module_name = "/proc/self/exe";
1123   uptr module_name_len = internal_readlink(
1124       default_module_name, buf, buf_len);
1125   int readlink_error;
1126   bool IsErr = internal_iserror(module_name_len, &readlink_error);
1127 #endif  // SANITIZER_SOLARIS
1128   if (IsErr) {
1129     // We can't read binary name for some reason, assume it's unknown.
1130     Report("WARNING: reading executable name failed with errno %d, "
1131            "some stack frames may not be symbolized\n", readlink_error);
1132     module_name_len = internal_snprintf(buf, buf_len, "%s",
1133                                         default_module_name);
1134     CHECK_LT(module_name_len, buf_len);
1135   }
1136   return module_name_len;
1137 #endif
1138 }
1139 #endif // !SANITIZER_OPENBSD
1140
1141 uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
1142 #if SANITIZER_LINUX
1143   char *tmpbuf;
1144   uptr tmpsize;
1145   uptr tmplen;
1146   if (ReadFileToBuffer("/proc/self/cmdline", &tmpbuf, &tmpsize, &tmplen,
1147                        1024 * 1024)) {
1148     internal_strncpy(buf, tmpbuf, buf_len);
1149     UnmapOrDie(tmpbuf, tmpsize);
1150     return internal_strlen(buf);
1151   }
1152 #endif
1153   return ReadBinaryName(buf, buf_len);
1154 }
1155
1156 // Match full names of the form /path/to/base_name{-,.}*
1157 bool LibraryNameIs(const char *full_name, const char *base_name) {
1158   const char *name = full_name;
1159   // Strip path.
1160   while (*name != '\0') name++;
1161   while (name > full_name && *name != '/') name--;
1162   if (*name == '/') name++;
1163   uptr base_name_length = internal_strlen(base_name);
1164   if (internal_strncmp(name, base_name, base_name_length)) return false;
1165   return (name[base_name_length] == '-' || name[base_name_length] == '.');
1166 }
1167
1168 #if !SANITIZER_ANDROID
1169 // Call cb for each region mapped by map.
1170 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) {
1171   CHECK_NE(map, nullptr);
1172 #if !SANITIZER_FREEBSD && !SANITIZER_OPENBSD
1173   typedef ElfW(Phdr) Elf_Phdr;
1174   typedef ElfW(Ehdr) Elf_Ehdr;
1175 #endif // !SANITIZER_FREEBSD && !SANITIZER_OPENBSD
1176   char *base = (char *)map->l_addr;
1177   Elf_Ehdr *ehdr = (Elf_Ehdr *)base;
1178   char *phdrs = base + ehdr->e_phoff;
1179   char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize;
1180
1181   // Find the segment with the minimum base so we can "relocate" the p_vaddr
1182   // fields.  Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC
1183   // objects have a non-zero base.
1184   uptr preferred_base = (uptr)-1;
1185   for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
1186     Elf_Phdr *phdr = (Elf_Phdr *)iter;
1187     if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr)
1188       preferred_base = (uptr)phdr->p_vaddr;
1189   }
1190
1191   // Compute the delta from the real base to get a relocation delta.
1192   sptr delta = (uptr)base - preferred_base;
1193   // Now we can figure out what the loader really mapped.
1194   for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
1195     Elf_Phdr *phdr = (Elf_Phdr *)iter;
1196     if (phdr->p_type == PT_LOAD) {
1197       uptr seg_start = phdr->p_vaddr + delta;
1198       uptr seg_end = seg_start + phdr->p_memsz;
1199       // None of these values are aligned.  We consider the ragged edges of the
1200       // load command as defined, since they are mapped from the file.
1201       seg_start = RoundDownTo(seg_start, GetPageSizeCached());
1202       seg_end = RoundUpTo(seg_end, GetPageSizeCached());
1203       cb((void *)seg_start, seg_end - seg_start);
1204     }
1205   }
1206 }
1207 #endif
1208
1209 #if defined(__x86_64__) && SANITIZER_LINUX
1210 // We cannot use glibc's clone wrapper, because it messes with the child
1211 // task's TLS. It writes the PID and TID of the child task to its thread
1212 // descriptor, but in our case the child task shares the thread descriptor with
1213 // the parent (because we don't know how to allocate a new thread
1214 // descriptor to keep glibc happy). So the stock version of clone(), when
1215 // used with CLONE_VM, would end up corrupting the parent's thread descriptor.
1216 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1217                     int *parent_tidptr, void *newtls, int *child_tidptr) {
1218   long long res;
1219   if (!fn || !child_stack)
1220     return -EINVAL;
1221   CHECK_EQ(0, (uptr)child_stack % 16);
1222   child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1223   ((unsigned long long *)child_stack)[0] = (uptr)fn;
1224   ((unsigned long long *)child_stack)[1] = (uptr)arg;
1225   register void *r8 __asm__("r8") = newtls;
1226   register int *r10 __asm__("r10") = child_tidptr;
1227   __asm__ __volatile__(
1228                        /* %rax = syscall(%rax = SYSCALL(clone),
1229                         *                %rdi = flags,
1230                         *                %rsi = child_stack,
1231                         *                %rdx = parent_tidptr,
1232                         *                %r8  = new_tls,
1233                         *                %r10 = child_tidptr)
1234                         */
1235                        "syscall\n"
1236
1237                        /* if (%rax != 0)
1238                         *   return;
1239                         */
1240                        "testq  %%rax,%%rax\n"
1241                        "jnz    1f\n"
1242
1243                        /* In the child. Terminate unwind chain. */
1244                        // XXX: We should also terminate the CFI unwind chain
1245                        // here. Unfortunately clang 3.2 doesn't support the
1246                        // necessary CFI directives, so we skip that part.
1247                        "xorq   %%rbp,%%rbp\n"
1248
1249                        /* Call "fn(arg)". */
1250                        "popq   %%rax\n"
1251                        "popq   %%rdi\n"
1252                        "call   *%%rax\n"
1253
1254                        /* Call _exit(%rax). */
1255                        "movq   %%rax,%%rdi\n"
1256                        "movq   %2,%%rax\n"
1257                        "syscall\n"
1258
1259                        /* Return to parent. */
1260                      "1:\n"
1261                        : "=a" (res)
1262                        : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
1263                          "S"(child_stack),
1264                          "D"(flags),
1265                          "d"(parent_tidptr),
1266                          "r"(r8),
1267                          "r"(r10)
1268                        : "memory", "r11", "rcx");
1269   return res;
1270 }
1271 #elif defined(__mips__)
1272 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1273                     int *parent_tidptr, void *newtls, int *child_tidptr) {
1274   long long res;
1275   if (!fn || !child_stack)
1276     return -EINVAL;
1277   CHECK_EQ(0, (uptr)child_stack % 16);
1278   child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1279   ((unsigned long long *)child_stack)[0] = (uptr)fn;
1280   ((unsigned long long *)child_stack)[1] = (uptr)arg;
1281   register void *a3 __asm__("$7") = newtls;
1282   register int *a4 __asm__("$8") = child_tidptr;
1283   // We don't have proper CFI directives here because it requires alot of code
1284   // for very marginal benefits.
1285   __asm__ __volatile__(
1286                        /* $v0 = syscall($v0 = __NR_clone,
1287                         * $a0 = flags,
1288                         * $a1 = child_stack,
1289                         * $a2 = parent_tidptr,
1290                         * $a3 = new_tls,
1291                         * $a4 = child_tidptr)
1292                         */
1293                        ".cprestore 16;\n"
1294                        "move $4,%1;\n"
1295                        "move $5,%2;\n"
1296                        "move $6,%3;\n"
1297                        "move $7,%4;\n"
1298                        /* Store the fifth argument on stack
1299                         * if we are using 32-bit abi.
1300                         */
1301 #if SANITIZER_WORDSIZE == 32
1302                        "lw %5,16($29);\n"
1303 #else
1304                        "move $8,%5;\n"
1305 #endif
1306                        "li $2,%6;\n"
1307                        "syscall;\n"
1308
1309                        /* if ($v0 != 0)
1310                         * return;
1311                         */
1312                        "bnez $2,1f;\n"
1313
1314                        /* Call "fn(arg)". */
1315 #if SANITIZER_WORDSIZE == 32
1316 #ifdef __BIG_ENDIAN__
1317                        "lw $25,4($29);\n"
1318                        "lw $4,12($29);\n"
1319 #else
1320                        "lw $25,0($29);\n"
1321                        "lw $4,8($29);\n"
1322 #endif
1323 #else
1324                        "ld $25,0($29);\n"
1325                        "ld $4,8($29);\n"
1326 #endif
1327                        "jal $25;\n"
1328
1329                        /* Call _exit($v0). */
1330                        "move $4,$2;\n"
1331                        "li $2,%7;\n"
1332                        "syscall;\n"
1333
1334                        /* Return to parent. */
1335                      "1:\n"
1336                        : "=r" (res)
1337                        : "r"(flags),
1338                          "r"(child_stack),
1339                          "r"(parent_tidptr),
1340                          "r"(a3),
1341                          "r"(a4),
1342                          "i"(__NR_clone),
1343                          "i"(__NR_exit)
1344                        : "memory", "$29" );
1345   return res;
1346 }
1347 #elif defined(__aarch64__)
1348 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1349                     int *parent_tidptr, void *newtls, int *child_tidptr) {
1350   long long res;
1351   if (!fn || !child_stack)
1352     return -EINVAL;
1353   CHECK_EQ(0, (uptr)child_stack % 16);
1354   child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1355   ((unsigned long long *)child_stack)[0] = (uptr)fn;
1356   ((unsigned long long *)child_stack)[1] = (uptr)arg;
1357
1358   register int (*__fn)(void *)  __asm__("x0") = fn;
1359   register void *__stack __asm__("x1") = child_stack;
1360   register int   __flags __asm__("x2") = flags;
1361   register void *__arg   __asm__("x3") = arg;
1362   register int  *__ptid  __asm__("x4") = parent_tidptr;
1363   register void *__tls   __asm__("x5") = newtls;
1364   register int  *__ctid  __asm__("x6") = child_tidptr;
1365
1366   __asm__ __volatile__(
1367                        "mov x0,x2\n" /* flags  */
1368                        "mov x2,x4\n" /* ptid  */
1369                        "mov x3,x5\n" /* tls  */
1370                        "mov x4,x6\n" /* ctid  */
1371                        "mov x8,%9\n" /* clone  */
1372
1373                        "svc 0x0\n"
1374
1375                        /* if (%r0 != 0)
1376                         *   return %r0;
1377                         */
1378                        "cmp x0, #0\n"
1379                        "bne 1f\n"
1380
1381                        /* In the child, now. Call "fn(arg)". */
1382                        "ldp x1, x0, [sp], #16\n"
1383                        "blr x1\n"
1384
1385                        /* Call _exit(%r0).  */
1386                        "mov x8, %10\n"
1387                        "svc 0x0\n"
1388                      "1:\n"
1389
1390                        : "=r" (res)
1391                        : "i"(-EINVAL),
1392                          "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg),
1393                          "r"(__ptid), "r"(__tls), "r"(__ctid),
1394                          "i"(__NR_clone), "i"(__NR_exit)
1395                        : "x30", "memory");
1396   return res;
1397 }
1398 #elif defined(__powerpc64__)
1399 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1400                    int *parent_tidptr, void *newtls, int *child_tidptr) {
1401   long long res;
1402 // Stack frame structure.
1403 #if SANITIZER_PPC64V1
1404 //   Back chain == 0        (SP + 112)
1405 // Frame (112 bytes):
1406 //   Parameter save area    (SP + 48), 8 doublewords
1407 //   TOC save area          (SP + 40)
1408 //   Link editor doubleword (SP + 32)
1409 //   Compiler doubleword    (SP + 24)
1410 //   LR save area           (SP + 16)
1411 //   CR save area           (SP + 8)
1412 //   Back chain             (SP + 0)
1413 # define FRAME_SIZE 112
1414 # define FRAME_TOC_SAVE_OFFSET 40
1415 #elif SANITIZER_PPC64V2
1416 //   Back chain == 0        (SP + 32)
1417 // Frame (32 bytes):
1418 //   TOC save area          (SP + 24)
1419 //   LR save area           (SP + 16)
1420 //   CR save area           (SP + 8)
1421 //   Back chain             (SP + 0)
1422 # define FRAME_SIZE 32
1423 # define FRAME_TOC_SAVE_OFFSET 24
1424 #else
1425 # error "Unsupported PPC64 ABI"
1426 #endif
1427   if (!fn || !child_stack)
1428     return -EINVAL;
1429   CHECK_EQ(0, (uptr)child_stack % 16);
1430
1431   register int (*__fn)(void *) __asm__("r3") = fn;
1432   register void *__cstack      __asm__("r4") = child_stack;
1433   register int __flags         __asm__("r5") = flags;
1434   register void *__arg         __asm__("r6") = arg;
1435   register int *__ptidptr      __asm__("r7") = parent_tidptr;
1436   register void *__newtls      __asm__("r8") = newtls;
1437   register int *__ctidptr      __asm__("r9") = child_tidptr;
1438
1439  __asm__ __volatile__(
1440            /* fn and arg are saved across the syscall */
1441            "mr 28, %5\n\t"
1442            "mr 27, %8\n\t"
1443
1444            /* syscall
1445              r0 == __NR_clone
1446              r3 == flags
1447              r4 == child_stack
1448              r5 == parent_tidptr
1449              r6 == newtls
1450              r7 == child_tidptr */
1451            "mr 3, %7\n\t"
1452            "mr 5, %9\n\t"
1453            "mr 6, %10\n\t"
1454            "mr 7, %11\n\t"
1455            "li 0, %3\n\t"
1456            "sc\n\t"
1457
1458            /* Test if syscall was successful */
1459            "cmpdi  cr1, 3, 0\n\t"
1460            "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t"
1461            "bne-   cr1, 1f\n\t"
1462
1463            /* Set up stack frame */
1464            "li    29, 0\n\t"
1465            "stdu  29, -8(1)\n\t"
1466            "stdu  1, -%12(1)\n\t"
1467            /* Do the function call */
1468            "std   2, %13(1)\n\t"
1469 #if SANITIZER_PPC64V1
1470            "ld    0, 0(28)\n\t"
1471            "ld    2, 8(28)\n\t"
1472            "mtctr 0\n\t"
1473 #elif SANITIZER_PPC64V2
1474            "mr    12, 28\n\t"
1475            "mtctr 12\n\t"
1476 #else
1477 # error "Unsupported PPC64 ABI"
1478 #endif
1479            "mr    3, 27\n\t"
1480            "bctrl\n\t"
1481            "ld    2, %13(1)\n\t"
1482
1483            /* Call _exit(r3) */
1484            "li 0, %4\n\t"
1485            "sc\n\t"
1486
1487            /* Return to parent */
1488            "1:\n\t"
1489            "mr %0, 3\n\t"
1490              : "=r" (res)
1491              : "0" (-1),
1492                "i" (EINVAL),
1493                "i" (__NR_clone),
1494                "i" (__NR_exit),
1495                "r" (__fn),
1496                "r" (__cstack),
1497                "r" (__flags),
1498                "r" (__arg),
1499                "r" (__ptidptr),
1500                "r" (__newtls),
1501                "r" (__ctidptr),
1502                "i" (FRAME_SIZE),
1503                "i" (FRAME_TOC_SAVE_OFFSET)
1504              : "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29");
1505   return res;
1506 }
1507 #elif defined(__i386__) && SANITIZER_LINUX
1508 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1509                     int *parent_tidptr, void *newtls, int *child_tidptr) {
1510   int res;
1511   if (!fn || !child_stack)
1512     return -EINVAL;
1513   CHECK_EQ(0, (uptr)child_stack % 16);
1514   child_stack = (char *)child_stack - 7 * sizeof(unsigned int);
1515   ((unsigned int *)child_stack)[0] = (uptr)flags;
1516   ((unsigned int *)child_stack)[1] = (uptr)0;
1517   ((unsigned int *)child_stack)[2] = (uptr)fn;
1518   ((unsigned int *)child_stack)[3] = (uptr)arg;
1519   __asm__ __volatile__(
1520                        /* %eax = syscall(%eax = SYSCALL(clone),
1521                         *                %ebx = flags,
1522                         *                %ecx = child_stack,
1523                         *                %edx = parent_tidptr,
1524                         *                %esi  = new_tls,
1525                         *                %edi = child_tidptr)
1526                         */
1527
1528                         /* Obtain flags */
1529                         "movl    (%%ecx), %%ebx\n"
1530                         /* Do the system call */
1531                         "pushl   %%ebx\n"
1532                         "pushl   %%esi\n"
1533                         "pushl   %%edi\n"
1534                         /* Remember the flag value.  */
1535                         "movl    %%ebx, (%%ecx)\n"
1536                         "int     $0x80\n"
1537                         "popl    %%edi\n"
1538                         "popl    %%esi\n"
1539                         "popl    %%ebx\n"
1540
1541                         /* if (%eax != 0)
1542                          *   return;
1543                          */
1544
1545                         "test    %%eax,%%eax\n"
1546                         "jnz    1f\n"
1547
1548                         /* terminate the stack frame */
1549                         "xorl   %%ebp,%%ebp\n"
1550                         /* Call FN. */
1551                         "call    *%%ebx\n"
1552 #ifdef PIC
1553                         "call    here\n"
1554                         "here:\n"
1555                         "popl    %%ebx\n"
1556                         "addl    $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n"
1557 #endif
1558                         /* Call exit */
1559                         "movl    %%eax, %%ebx\n"
1560                         "movl    %2, %%eax\n"
1561                         "int     $0x80\n"
1562                         "1:\n"
1563                        : "=a" (res)
1564                        : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
1565                          "c"(child_stack),
1566                          "d"(parent_tidptr),
1567                          "S"(newtls),
1568                          "D"(child_tidptr)
1569                        : "memory");
1570   return res;
1571 }
1572 #elif defined(__arm__) && SANITIZER_LINUX
1573 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1574                     int *parent_tidptr, void *newtls, int *child_tidptr) {
1575   unsigned int res;
1576   if (!fn || !child_stack)
1577     return -EINVAL;
1578   child_stack = (char *)child_stack - 2 * sizeof(unsigned int);
1579   ((unsigned int *)child_stack)[0] = (uptr)fn;
1580   ((unsigned int *)child_stack)[1] = (uptr)arg;
1581   register int r0 __asm__("r0") = flags;
1582   register void *r1 __asm__("r1") = child_stack;
1583   register int *r2 __asm__("r2") = parent_tidptr;
1584   register void *r3 __asm__("r3") = newtls;
1585   register int *r4 __asm__("r4") = child_tidptr;
1586   register int r7 __asm__("r7") = __NR_clone;
1587
1588 #if __ARM_ARCH > 4 || defined (__ARM_ARCH_4T__)
1589 # define ARCH_HAS_BX
1590 #endif
1591 #if __ARM_ARCH > 4
1592 # define ARCH_HAS_BLX
1593 #endif
1594
1595 #ifdef ARCH_HAS_BX
1596 # ifdef ARCH_HAS_BLX
1597 #  define BLX(R) "blx "  #R "\n"
1598 # else
1599 #  define BLX(R) "mov lr, pc; bx " #R "\n"
1600 # endif
1601 #else
1602 # define BLX(R)  "mov lr, pc; mov pc," #R "\n"
1603 #endif
1604
1605   __asm__ __volatile__(
1606                        /* %r0 = syscall(%r7 = SYSCALL(clone),
1607                         *               %r0 = flags,
1608                         *               %r1 = child_stack,
1609                         *               %r2 = parent_tidptr,
1610                         *               %r3  = new_tls,
1611                         *               %r4 = child_tidptr)
1612                         */
1613
1614                        /* Do the system call */
1615                        "swi 0x0\n"
1616
1617                        /* if (%r0 != 0)
1618                         *   return %r0;
1619                         */
1620                        "cmp r0, #0\n"
1621                        "bne 1f\n"
1622
1623                        /* In the child, now. Call "fn(arg)". */
1624                        "ldr r0, [sp, #4]\n"
1625                        "ldr ip, [sp], #8\n"
1626                        BLX(ip)
1627                        /* Call _exit(%r0). */
1628                        "mov r7, %7\n"
1629                        "swi 0x0\n"
1630                        "1:\n"
1631                        "mov %0, r0\n"
1632                        : "=r"(res)
1633                        : "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7),
1634                          "i"(__NR_exit)
1635                        : "memory");
1636   return res;
1637 }
1638 #endif  // defined(__x86_64__) && SANITIZER_LINUX
1639
1640 #if SANITIZER_ANDROID
1641 #if __ANDROID_API__ < 21
1642 extern "C" __attribute__((weak)) int dl_iterate_phdr(
1643     int (*)(struct dl_phdr_info *, size_t, void *), void *);
1644 #endif
1645
1646 static int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size,
1647                                    void *data) {
1648   // Any name starting with "lib" indicates a bug in L where library base names
1649   // are returned instead of paths.
1650   if (info->dlpi_name && info->dlpi_name[0] == 'l' &&
1651       info->dlpi_name[1] == 'i' && info->dlpi_name[2] == 'b') {
1652     *(bool *)data = true;
1653     return 1;
1654   }
1655   return 0;
1656 }
1657
1658 static atomic_uint32_t android_api_level;
1659
1660 static AndroidApiLevel AndroidDetectApiLevelStatic() {
1661 #if __ANDROID_API__ <= 19
1662   return ANDROID_KITKAT;
1663 #elif __ANDROID_API__ <= 22
1664   return ANDROID_LOLLIPOP_MR1;
1665 #else
1666   return ANDROID_POST_LOLLIPOP;
1667 #endif
1668 }
1669
1670 static AndroidApiLevel AndroidDetectApiLevel() {
1671   if (!&dl_iterate_phdr)
1672     return ANDROID_KITKAT; // K or lower
1673   bool base_name_seen = false;
1674   dl_iterate_phdr(dl_iterate_phdr_test_cb, &base_name_seen);
1675   if (base_name_seen)
1676     return ANDROID_LOLLIPOP_MR1; // L MR1
1677   return ANDROID_POST_LOLLIPOP;   // post-L
1678   // Plain L (API level 21) is completely broken wrt ASan and not very
1679   // interesting to detect.
1680 }
1681
1682 extern "C" __attribute__((weak)) void* _DYNAMIC;
1683
1684 AndroidApiLevel AndroidGetApiLevel() {
1685   AndroidApiLevel level =
1686       (AndroidApiLevel)atomic_load(&android_api_level, memory_order_relaxed);
1687   if (level) return level;
1688   level = &_DYNAMIC == nullptr ? AndroidDetectApiLevelStatic()
1689                                : AndroidDetectApiLevel();
1690   atomic_store(&android_api_level, level, memory_order_relaxed);
1691   return level;
1692 }
1693
1694 #endif
1695
1696 static HandleSignalMode GetHandleSignalModeImpl(int signum) {
1697   switch (signum) {
1698     case SIGABRT:
1699       return common_flags()->handle_abort;
1700     case SIGILL:
1701       return common_flags()->handle_sigill;
1702     case SIGTRAP:
1703       return common_flags()->handle_sigtrap;
1704     case SIGFPE:
1705       return common_flags()->handle_sigfpe;
1706     case SIGSEGV:
1707       return common_flags()->handle_segv;
1708     case SIGBUS:
1709       return common_flags()->handle_sigbus;
1710   }
1711   return kHandleSignalNo;
1712 }
1713
1714 HandleSignalMode GetHandleSignalMode(int signum) {
1715   HandleSignalMode result = GetHandleSignalModeImpl(signum);
1716   if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler)
1717     return kHandleSignalExclusive;
1718   return result;
1719 }
1720
1721 #if !SANITIZER_GO
1722 void *internal_start_thread(void(*func)(void *arg), void *arg) {
1723   // Start the thread with signals blocked, otherwise it can steal user signals.
1724   __sanitizer_sigset_t set, old;
1725   internal_sigfillset(&set);
1726 #if SANITIZER_LINUX && !SANITIZER_ANDROID
1727   // Glibc uses SIGSETXID signal during setuid call. If this signal is blocked
1728   // on any thread, setuid call hangs (see test/tsan/setuid.c).
1729   internal_sigdelset(&set, 33);
1730 #endif
1731   internal_sigprocmask(SIG_SETMASK, &set, &old);
1732   void *th;
1733   real_pthread_create(&th, nullptr, (void*(*)(void *arg))func, arg);
1734   internal_sigprocmask(SIG_SETMASK, &old, nullptr);
1735   return th;
1736 }
1737
1738 void internal_join_thread(void *th) {
1739   real_pthread_join(th, nullptr);
1740 }
1741 #else
1742 void *internal_start_thread(void (*func)(void *), void *arg) { return 0; }
1743
1744 void internal_join_thread(void *th) {}
1745 #endif
1746
1747 #if defined(__aarch64__)
1748 // Android headers in the older NDK releases miss this definition.
1749 struct __sanitizer_esr_context {
1750   struct _aarch64_ctx head;
1751   uint64_t esr;
1752 };
1753
1754 static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
1755   static const u32 kEsrMagic = 0x45535201;
1756   u8 *aux = ucontext->uc_mcontext.__reserved;
1757   while (true) {
1758     _aarch64_ctx *ctx = (_aarch64_ctx *)aux;
1759     if (ctx->size == 0) break;
1760     if (ctx->magic == kEsrMagic) {
1761       *esr = ((__sanitizer_esr_context *)ctx)->esr;
1762       return true;
1763     }
1764     aux += ctx->size;
1765   }
1766   return false;
1767 }
1768 #endif
1769
1770 #if SANITIZER_OPENBSD
1771 using Context = sigcontext;
1772 #else
1773 using Context = ucontext_t;
1774 #endif
1775
1776 SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
1777   Context *ucontext = (Context *)context;
1778 #if defined(__x86_64__) || defined(__i386__)
1779   static const uptr PF_WRITE = 1U << 1;
1780 #if SANITIZER_FREEBSD
1781   uptr err = ucontext->uc_mcontext.mc_err;
1782 #elif SANITIZER_NETBSD
1783   uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR];
1784 #elif SANITIZER_OPENBSD
1785   uptr err = ucontext->sc_err;
1786 #elif SANITIZER_SOLARIS && defined(__i386__)
1787   const int Err = 13;
1788   uptr err = ucontext->uc_mcontext.gregs[Err];
1789 #else
1790   uptr err = ucontext->uc_mcontext.gregs[REG_ERR];
1791 #endif // SANITIZER_FREEBSD
1792   return err & PF_WRITE ? WRITE : READ;
1793 #elif defined(__mips__)
1794   uint32_t *exception_source;
1795   uint32_t faulty_instruction;
1796   uint32_t op_code;
1797
1798   exception_source = (uint32_t *)ucontext->uc_mcontext.pc;
1799   faulty_instruction = (uint32_t)(*exception_source);
1800
1801   op_code = (faulty_instruction >> 26) & 0x3f;
1802
1803   // FIXME: Add support for FPU, microMIPS, DSP, MSA memory instructions.
1804   switch (op_code) {
1805     case 0x28:  // sb
1806     case 0x29:  // sh
1807     case 0x2b:  // sw
1808     case 0x3f:  // sd
1809 #if __mips_isa_rev < 6
1810     case 0x2c:  // sdl
1811     case 0x2d:  // sdr
1812     case 0x2a:  // swl
1813     case 0x2e:  // swr
1814 #endif
1815       return SignalContext::WRITE;
1816
1817     case 0x20:  // lb
1818     case 0x24:  // lbu
1819     case 0x21:  // lh
1820     case 0x25:  // lhu
1821     case 0x23:  // lw
1822     case 0x27:  // lwu
1823     case 0x37:  // ld
1824 #if __mips_isa_rev < 6
1825     case 0x1a:  // ldl
1826     case 0x1b:  // ldr
1827     case 0x22:  // lwl
1828     case 0x26:  // lwr
1829 #endif
1830       return SignalContext::READ;
1831 #if __mips_isa_rev == 6
1832     case 0x3b:  // pcrel
1833       op_code = (faulty_instruction >> 19) & 0x3;
1834       switch (op_code) {
1835         case 0x1:  // lwpc
1836         case 0x2:  // lwupc
1837           return SignalContext::READ;
1838       }
1839 #endif
1840   }
1841   return SignalContext::UNKNOWN;
1842 #elif defined(__arm__)
1843   static const uptr FSR_WRITE = 1U << 11;
1844   uptr fsr = ucontext->uc_mcontext.error_code;
1845   return fsr & FSR_WRITE ? WRITE : READ;
1846 #elif defined(__aarch64__)
1847   static const u64 ESR_ELx_WNR = 1U << 6;
1848   u64 esr;
1849   if (!Aarch64GetESR(ucontext, &esr)) return UNKNOWN;
1850   return esr & ESR_ELx_WNR ? WRITE : READ;
1851 #elif SANITIZER_SOLARIS && defined(__sparc__)
1852   // Decode the instruction to determine the access type.
1853   // From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype).
1854   uptr pc = ucontext->uc_mcontext.gregs[REG_PC];
1855   u32 instr = *(u32 *)pc;
1856   return (instr >> 21) & 1 ? WRITE: READ;
1857 #else
1858   (void)ucontext;
1859   return UNKNOWN;  // FIXME: Implement.
1860 #endif
1861 }
1862
1863 void SignalContext::DumpAllRegisters(void *context) {
1864   // FIXME: Implement this.
1865 }
1866
1867 static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
1868 #if SANITIZER_NETBSD
1869   // This covers all NetBSD architectures
1870   ucontext_t *ucontext = (ucontext_t *)context;
1871   *pc = _UC_MACHINE_PC(ucontext);
1872   *bp = _UC_MACHINE_FP(ucontext);
1873   *sp = _UC_MACHINE_SP(ucontext);
1874 #elif defined(__arm__)
1875   ucontext_t *ucontext = (ucontext_t*)context;
1876   *pc = ucontext->uc_mcontext.arm_pc;
1877   *bp = ucontext->uc_mcontext.arm_fp;
1878   *sp = ucontext->uc_mcontext.arm_sp;
1879 #elif defined(__aarch64__)
1880   ucontext_t *ucontext = (ucontext_t*)context;
1881   *pc = ucontext->uc_mcontext.pc;
1882   *bp = ucontext->uc_mcontext.regs[29];
1883   *sp = ucontext->uc_mcontext.sp;
1884 #elif defined(__hppa__)
1885   ucontext_t *ucontext = (ucontext_t*)context;
1886   *pc = ucontext->uc_mcontext.sc_iaoq[0];
1887   /* GCC uses %r3 whenever a frame pointer is needed.  */
1888   *bp = ucontext->uc_mcontext.sc_gr[3];
1889   *sp = ucontext->uc_mcontext.sc_gr[30];
1890 #elif defined(__x86_64__)
1891 # if SANITIZER_FREEBSD
1892   ucontext_t *ucontext = (ucontext_t*)context;
1893   *pc = ucontext->uc_mcontext.mc_rip;
1894   *bp = ucontext->uc_mcontext.mc_rbp;
1895   *sp = ucontext->uc_mcontext.mc_rsp;
1896 #elif SANITIZER_OPENBSD
1897   sigcontext *ucontext = (sigcontext *)context;
1898   *pc = ucontext->sc_rip;
1899   *bp = ucontext->sc_rbp;
1900   *sp = ucontext->sc_rsp;
1901 # else
1902   ucontext_t *ucontext = (ucontext_t*)context;
1903   *pc = ucontext->uc_mcontext.gregs[REG_RIP];
1904   *bp = ucontext->uc_mcontext.gregs[REG_RBP];
1905   *sp = ucontext->uc_mcontext.gregs[REG_RSP];
1906 # endif
1907 #elif defined(__i386__)
1908 # if SANITIZER_FREEBSD
1909   ucontext_t *ucontext = (ucontext_t*)context;
1910   *pc = ucontext->uc_mcontext.mc_eip;
1911   *bp = ucontext->uc_mcontext.mc_ebp;
1912   *sp = ucontext->uc_mcontext.mc_esp;
1913 #elif SANITIZER_OPENBSD
1914   sigcontext *ucontext = (sigcontext *)context;
1915   *pc = ucontext->sc_eip;
1916   *bp = ucontext->sc_ebp;
1917   *sp = ucontext->sc_esp;
1918 # else
1919   ucontext_t *ucontext = (ucontext_t*)context;
1920 # if SANITIZER_SOLARIS
1921   /* Use the numeric values: the symbolic ones are undefined by llvm
1922      include/llvm/Support/Solaris.h.  */
1923 # ifndef REG_EIP
1924 #  define REG_EIP 14 // REG_PC
1925 # endif
1926 # ifndef REG_EBP
1927 #  define REG_EBP  6 // REG_FP
1928 # endif
1929 # ifndef REG_ESP
1930 #  define REG_ESP 17 // REG_SP
1931 # endif
1932 # endif
1933   *pc = ucontext->uc_mcontext.gregs[REG_EIP];
1934   *bp = ucontext->uc_mcontext.gregs[REG_EBP];
1935   *sp = ucontext->uc_mcontext.gregs[REG_ESP];
1936 # endif
1937 #elif defined(__powerpc__) || defined(__powerpc64__)
1938   ucontext_t *ucontext = (ucontext_t*)context;
1939   *pc = ucontext->uc_mcontext.regs->nip;
1940   *sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
1941   // The powerpc{,64}-linux ABIs do not specify r31 as the frame
1942   // pointer, but GCC always uses r31 when we need a frame pointer.
1943   *bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
1944 #elif defined(__sparc__)
1945   ucontext_t *ucontext = (ucontext_t*)context;
1946   uptr *stk_ptr;
1947 # if defined(__sparcv9) || defined (__arch64__)
1948 # ifndef MC_PC
1949 #  define MC_PC REG_PC
1950 # endif
1951 # ifndef MC_O6
1952 #  define MC_O6 REG_O6
1953 # endif
1954 # if SANITIZER_SOLARIS
1955 #  define mc_gregs gregs
1956 # endif
1957   *pc = ucontext->uc_mcontext.mc_gregs[MC_PC];
1958   *sp = ucontext->uc_mcontext.mc_gregs[MC_O6];
1959   stk_ptr = (uptr *) (*sp + 2047);
1960   *bp = stk_ptr[15];
1961 # else
1962   *pc = ucontext->uc_mcontext.gregs[REG_PC];
1963   *sp = ucontext->uc_mcontext.gregs[REG_O6];
1964   stk_ptr = (uptr *) *sp;
1965   *bp = stk_ptr[15];
1966 # endif
1967 #elif defined(__mips__)
1968   ucontext_t *ucontext = (ucontext_t*)context;
1969   *pc = ucontext->uc_mcontext.pc;
1970   *bp = ucontext->uc_mcontext.gregs[30];
1971   *sp = ucontext->uc_mcontext.gregs[29];
1972 #elif defined(__s390__)
1973   ucontext_t *ucontext = (ucontext_t*)context;
1974 # if defined(__s390x__)
1975   *pc = ucontext->uc_mcontext.psw.addr;
1976 # else
1977   *pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff;
1978 # endif
1979   *bp = ucontext->uc_mcontext.gregs[11];
1980   *sp = ucontext->uc_mcontext.gregs[15];
1981 #else
1982 # error "Unsupported arch"
1983 #endif
1984 }
1985
1986 void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); }
1987
1988 void MaybeReexec() {
1989   // No need to re-exec on Linux.
1990 }
1991
1992 void CheckASLR() {
1993 #if SANITIZER_NETBSD
1994   int mib[3];
1995   int paxflags;
1996   uptr len = sizeof(paxflags);
1997
1998   mib[0] = CTL_PROC;
1999   mib[1] = internal_getpid();
2000   mib[2] = PROC_PID_PAXFLAGS;
2001
2002   if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
2003     Printf("sysctl failed\n");
2004     Die();
2005   }
2006
2007   if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_ASLR)) {
2008     Printf("This sanitizer is not compatible with enabled ASLR\n");
2009     Die();
2010   }
2011 #else
2012   // Do nothing
2013 #endif
2014 }
2015
2016 void PrintModuleMap() { }
2017
2018 void CheckNoDeepBind(const char *filename, int flag) {
2019 #ifdef RTLD_DEEPBIND
2020   if (flag & RTLD_DEEPBIND) {
2021     Report(
2022         "You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag"
2023         " which is incompatibe with sanitizer runtime "
2024         "(see https://github.com/google/sanitizers/issues/611 for details"
2025         "). If you want to run %s library under sanitizers please remove "
2026         "RTLD_DEEPBIND from dlopen flags.\n",
2027         filename, filename);
2028     Die();
2029   }
2030 #endif
2031 }
2032
2033 uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
2034                               uptr *largest_gap_found,
2035                               uptr *max_occupied_addr) {
2036   UNREACHABLE("FindAvailableMemoryRange is not available");
2037   return 0;
2038 }
2039
2040 bool GetRandom(void *buffer, uptr length, bool blocking) {
2041   if (!buffer || !length || length > 256)
2042     return false;
2043 #if SANITIZER_USE_GETENTROPY
2044   uptr rnd = getentropy(buffer, length);
2045   int rverrno = 0;
2046   if (internal_iserror(rnd, &rverrno) && rverrno == EFAULT)
2047     return false;
2048   else if (rnd == 0)
2049     return true;
2050 #endif // SANITIZER_USE_GETENTROPY
2051
2052 #if SANITIZER_USE_GETRANDOM
2053   static atomic_uint8_t skip_getrandom_syscall;
2054   if (!atomic_load_relaxed(&skip_getrandom_syscall)) {
2055     // Up to 256 bytes, getrandom will not be interrupted.
2056     uptr res = internal_syscall(SYSCALL(getrandom), buffer, length,
2057                                 blocking ? 0 : GRND_NONBLOCK);
2058     int rverrno = 0;
2059     if (internal_iserror(res, &rverrno) && rverrno == ENOSYS)
2060       atomic_store_relaxed(&skip_getrandom_syscall, 1);
2061     else if (res == length)
2062       return true;
2063   }
2064 #endif // SANITIZER_USE_GETRANDOM
2065   // Up to 256 bytes, a read off /dev/urandom will not be interrupted.
2066   // blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom.
2067   uptr fd = internal_open("/dev/urandom", O_RDONLY);
2068   if (internal_iserror(fd))
2069     return false;
2070   uptr res = internal_read(fd, buffer, length);
2071   if (internal_iserror(res))
2072     return false;
2073   internal_close(fd);
2074   return true;
2075 }
2076
2077 } // namespace __sanitizer
2078
2079 #endif