master
   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 || SANITIZER_HAIKU
  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.  sparc64 is similar, using
  37// syscall(__NR_stat64) and struct kernel_stat64.
  38#  if SANITIZER_LINUX && (SANITIZER_MIPS64 || SANITIZER_SPARC64)
  39#    include <asm/unistd.h>
  40#    include <sys/types.h>
  41#    define stat kernel_stat
  42#    if SANITIZER_SPARC64
  43#      define stat64 kernel_stat64
  44#    endif
  45#    if SANITIZER_GO
  46#      undef st_atime
  47#      undef st_mtime
  48#      undef st_ctime
  49#      define st_atime st_atim
  50#      define st_mtime st_mtim
  51#      define st_ctime st_ctim
  52#    endif
  53#    include <asm/stat.h>
  54#    undef stat
  55#    undef stat64
  56#  endif
  57
  58#  include <dlfcn.h>
  59#  include <errno.h>
  60#  include <fcntl.h>
  61#  include <link.h>
  62#  include <pthread.h>
  63#  include <sched.h>
  64#  include <signal.h>
  65#  include <sys/mman.h>
  66#  if !SANITIZER_SOLARIS && !SANITIZER_HAIKU
  67#    include <sys/ptrace.h>
  68#  endif
  69#  include <sys/resource.h>
  70#  include <sys/stat.h>
  71#  if !SANITIZER_HAIKU
  72#    include <sys/syscall.h>
  73#    include <ucontext.h>
  74#  endif
  75#  include <sys/time.h>
  76#  include <sys/types.h>
  77#  include <unistd.h>
  78
  79#  if SANITIZER_LINUX
  80#    include <sys/utsname.h>
  81#  endif
  82
  83#  if SANITIZER_LINUX && !SANITIZER_ANDROID
  84#    include <sys/personality.h>
  85#  endif
  86
  87#  if SANITIZER_ANDROID && __ANDROID_API__ < 35
  88// The weak `strerrorname_np` (introduced in API level 35) definition,
  89// allows for checking the API level at runtime.
  90extern "C" SANITIZER_WEAK_ATTRIBUTE const char *strerrorname_np(int);
  91#  endif
  92
  93#  if SANITIZER_LINUX && defined(__loongarch__)
  94#    include <sys/sysmacros.h>
  95#  endif
  96
  97#  if SANITIZER_LINUX && defined(__powerpc64__)
  98#    include <asm/ptrace.h>
  99#  endif
 100
 101#  if SANITIZER_FREEBSD
 102#    include <machine/atomic.h>
 103#    include <sys/exec.h>
 104#    include <sys/procctl.h>
 105#    include <sys/sysctl.h>
 106extern "C" {
 107// <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on
 108// FreeBSD 9.2 and 10.0.
 109#    include <sys/umtx.h>
 110}
 111#    include <sys/thr.h>
 112#  endif  // SANITIZER_FREEBSD
 113
 114#  if SANITIZER_NETBSD
 115#    include <limits.h>  // For NAME_MAX
 116#    include <sys/exec.h>
 117#    include <sys/sysctl.h>
 118extern struct ps_strings *__ps_strings;
 119#  endif  // SANITIZER_NETBSD
 120
 121#  if SANITIZER_SOLARIS
 122#    include <stddef.h>
 123#    include <stdlib.h>
 124#    include <sys/frame.h>
 125#    include <thread.h>
 126#    define environ _environ
 127#  endif
 128
 129#  if SANITIZER_HAIKU
 130#    include <OS.h>
 131#    include <elf.h>
 132#    include <image.h>
 133extern "C" char **__libc_argv;
 134#  endif
 135
 136extern char **environ;
 137
 138#  if SANITIZER_LINUX
 139// <linux/time.h>
 140struct kernel_timeval {
 141  long tv_sec;
 142  long tv_usec;
 143};
 144
 145// <linux/futex.h> is broken on some linux distributions.
 146const int FUTEX_WAIT = 0;
 147const int FUTEX_WAKE = 1;
 148const int FUTEX_PRIVATE_FLAG = 128;
 149const int FUTEX_WAIT_PRIVATE = FUTEX_WAIT | FUTEX_PRIVATE_FLAG;
 150const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG;
 151#  endif  // SANITIZER_LINUX
 152
 153// Are we using 32-bit or 64-bit Linux syscalls?
 154// x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
 155// but it still needs to use 64-bit syscalls.
 156#  if SANITIZER_LINUX &&                                \
 157      (defined(__x86_64__) || defined(__powerpc64__) || \
 158       SANITIZER_WORDSIZE == 64 ||                      \
 159       (defined(__mips__) && defined(_ABIN32) && _MIPS_SIM == _ABIN32))
 160#    define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
 161#  else
 162#    define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
 163#  endif
 164
 165// Note : FreeBSD implemented both Linux and OpenBSD apis.
 166#  if SANITIZER_LINUX && defined(__NR_getrandom)
 167#    if !defined(GRND_NONBLOCK)
 168#      define GRND_NONBLOCK 1
 169#    endif
 170#    define SANITIZER_USE_GETRANDOM 1
 171#  else
 172#    define SANITIZER_USE_GETRANDOM 0
 173#  endif  // SANITIZER_LINUX && defined(__NR_getrandom)
 174
 175#  if SANITIZER_FREEBSD
 176#    define SANITIZER_USE_GETENTROPY 1
 177#  endif
 178
 179namespace __sanitizer {
 180
 181void SetSigProcMask(__sanitizer_sigset_t *set, __sanitizer_sigset_t *oldset) {
 182  CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, set, oldset));
 183}
 184
 185#  if SANITIZER_LINUX
 186// Deletes the specified signal from newset, if it is not present in oldset
 187// Equivalently: newset[signum] = newset[signum] & oldset[signum]
 188static void KeepUnblocked(__sanitizer_sigset_t &newset,
 189                          __sanitizer_sigset_t &oldset, int signum) {
 190  // FIXME: https://github.com/google/sanitizers/issues/1816
 191  if (SANITIZER_ANDROID || !internal_sigismember(&oldset, signum))
 192    internal_sigdelset(&newset, signum);
 193}
 194#  endif
 195
 196// Block asynchronous signals
 197void BlockSignals(__sanitizer_sigset_t *oldset) {
 198  __sanitizer_sigset_t newset;
 199  internal_sigfillset(&newset);
 200
 201#  if SANITIZER_LINUX
 202  __sanitizer_sigset_t currentset;
 203
 204#    if !SANITIZER_ANDROID
 205  // FIXME: https://github.com/google/sanitizers/issues/1816
 206  SetSigProcMask(NULL, &currentset);
 207
 208  // Glibc uses SIGSETXID signal during setuid call. If this signal is blocked
 209  // on any thread, setuid call hangs.
 210  // See test/sanitizer_common/TestCases/Linux/setuid.c.
 211  KeepUnblocked(newset, currentset, 33);
 212#    endif  // !SANITIZER_ANDROID
 213
 214  // Seccomp-BPF-sandboxed processes rely on SIGSYS to handle trapped syscalls.
 215  // If this signal is blocked, such calls cannot be handled and the process may
 216  // hang.
 217  KeepUnblocked(newset, currentset, 31);
 218
 219#    if !SANITIZER_ANDROID
 220  // Don't block synchronous signals
 221  // but also don't unblock signals that the user had deliberately blocked.
 222  // FIXME: https://github.com/google/sanitizers/issues/1816
 223  KeepUnblocked(newset, currentset, SIGSEGV);
 224  KeepUnblocked(newset, currentset, SIGBUS);
 225  KeepUnblocked(newset, currentset, SIGILL);
 226  KeepUnblocked(newset, currentset, SIGTRAP);
 227  KeepUnblocked(newset, currentset, SIGABRT);
 228  KeepUnblocked(newset, currentset, SIGFPE);
 229  KeepUnblocked(newset, currentset, SIGPIPE);
 230#    endif  //! SANITIZER_ANDROID
 231
 232#  endif  // SANITIZER_LINUX
 233
 234  SetSigProcMask(&newset, oldset);
 235}
 236
 237ScopedBlockSignals::ScopedBlockSignals(__sanitizer_sigset_t *copy) {
 238  BlockSignals(&saved_);
 239  if (copy)
 240    internal_memcpy(copy, &saved_, sizeof(saved_));
 241}
 242
 243ScopedBlockSignals::~ScopedBlockSignals() { SetSigProcMask(&saved_, nullptr); }
 244
 245#  if SANITIZER_LINUX && defined(__x86_64__)
 246#    include "sanitizer_syscall_linux_x86_64.inc"
 247#  elif SANITIZER_LINUX && SANITIZER_RISCV64
 248#    include "sanitizer_syscall_linux_riscv64.inc"
 249#  elif SANITIZER_LINUX && defined(__aarch64__)
 250#    include "sanitizer_syscall_linux_aarch64.inc"
 251#  elif SANITIZER_LINUX && defined(__arm__)
 252#    include "sanitizer_syscall_linux_arm.inc"
 253#  elif SANITIZER_LINUX && defined(__hexagon__)
 254#    include "sanitizer_syscall_linux_hexagon.inc"
 255#  elif SANITIZER_LINUX && SANITIZER_LOONGARCH64
 256#    include "sanitizer_syscall_linux_loongarch64.inc"
 257#  else
 258#    include "sanitizer_syscall_generic.inc"
 259#  endif
 260
 261// --------------- sanitizer_libc.h
 262#  if !SANITIZER_SOLARIS && !SANITIZER_NETBSD && !SANITIZER_HAIKU
 263#    if !SANITIZER_S390
 264uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
 265                   u64 offset) {
 266  /* zig patch: use direct syscall for freebsd mmap */
 267#      if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
 268  return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd,
 269                          offset);
 270#      else
 271  // mmap2 specifies file offset in 4096-byte units.
 272  CHECK(IsAligned(offset, 4096));
 273  return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd,
 274                          (OFF_T)(offset / 4096));
 275#      endif
 276}
 277#    endif  // !SANITIZER_S390
 278
 279uptr internal_munmap(void *addr, uptr length) {
 280  return internal_syscall(SYSCALL(munmap), (uptr)addr, length);
 281}
 282
 283#    if SANITIZER_LINUX
 284uptr internal_mremap(void *old_address, uptr old_size, uptr new_size, int flags,
 285                     void *new_address) {
 286  return internal_syscall(SYSCALL(mremap), (uptr)old_address, old_size,
 287                          new_size, flags, (uptr)new_address);
 288}
 289#    endif
 290
 291int internal_mprotect(void *addr, uptr length, int prot) {
 292  return internal_syscall(SYSCALL(mprotect), (uptr)addr, length, prot);
 293}
 294
 295int internal_madvise(uptr addr, uptr length, int advice) {
 296  return internal_syscall(SYSCALL(madvise), addr, length, advice);
 297}
 298
 299#    if SANITIZER_FREEBSD
 300uptr internal_close_range(fd_t lowfd, fd_t highfd, int flags) {
 301  return internal_syscall(SYSCALL(close_range), lowfd, highfd, flags);
 302}
 303#    endif
 304uptr internal_close(fd_t fd) { return internal_syscall(SYSCALL(close), fd); }
 305
 306uptr internal_open(const char *filename, int flags) {
 307#    if SANITIZER_LINUX
 308  return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags);
 309#    else
 310  return internal_syscall(SYSCALL(open), (uptr)filename, flags);
 311#    endif
 312}
 313
 314uptr internal_open(const char *filename, int flags, u32 mode) {
 315#    if SANITIZER_LINUX
 316  return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags,
 317                          mode);
 318#    else
 319  return internal_syscall(SYSCALL(open), (uptr)filename, flags, mode);
 320#    endif
 321}
 322
 323uptr internal_read(fd_t fd, void *buf, uptr count) {
 324  sptr res;
 325  HANDLE_EINTR(res,
 326               (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf, count));
 327  return res;
 328}
 329
 330uptr internal_write(fd_t fd, const void *buf, uptr count) {
 331  sptr res;
 332  HANDLE_EINTR(res,
 333               (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf, count));
 334  return res;
 335}
 336
 337uptr internal_ftruncate(fd_t fd, uptr size) {
 338  sptr res;
 339  HANDLE_EINTR(res,
 340               (sptr)internal_syscall(SYSCALL(ftruncate), fd, (OFF_T)size));
 341  return res;
 342}
 343
 344#    if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && SANITIZER_LINUX
 345static void stat64_to_stat(struct stat64 *in, struct stat *out) {
 346  internal_memset(out, 0, sizeof(*out));
 347  out->st_dev = in->st_dev;
 348  out->st_ino = in->st_ino;
 349  out->st_mode = in->st_mode;
 350  out->st_nlink = in->st_nlink;
 351  out->st_uid = in->st_uid;
 352  out->st_gid = in->st_gid;
 353  out->st_rdev = in->st_rdev;
 354  out->st_size = in->st_size;
 355  out->st_blksize = in->st_blksize;
 356  out->st_blocks = in->st_blocks;
 357  out->st_atime = in->st_atime;
 358  out->st_mtime = in->st_mtime;
 359  out->st_ctime = in->st_ctime;
 360}
 361#    endif
 362
 363#    if SANITIZER_LINUX && defined(__loongarch__)
 364static void statx_to_stat(struct statx *in, struct stat *out) {
 365  internal_memset(out, 0, sizeof(*out));
 366  out->st_dev = makedev(in->stx_dev_major, in->stx_dev_minor);
 367  out->st_ino = in->stx_ino;
 368  out->st_mode = in->stx_mode;
 369  out->st_nlink = in->stx_nlink;
 370  out->st_uid = in->stx_uid;
 371  out->st_gid = in->stx_gid;
 372  out->st_rdev = makedev(in->stx_rdev_major, in->stx_rdev_minor);
 373  out->st_size = in->stx_size;
 374  out->st_blksize = in->stx_blksize;
 375  out->st_blocks = in->stx_blocks;
 376  out->st_atime = in->stx_atime.tv_sec;
 377  out->st_atim.tv_nsec = in->stx_atime.tv_nsec;
 378  out->st_mtime = in->stx_mtime.tv_sec;
 379  out->st_mtim.tv_nsec = in->stx_mtime.tv_nsec;
 380  out->st_ctime = in->stx_ctime.tv_sec;
 381  out->st_ctim.tv_nsec = in->stx_ctime.tv_nsec;
 382}
 383#    endif
 384
 385#    if SANITIZER_MIPS64 || SANITIZER_SPARC64
 386#      if SANITIZER_MIPS64
 387typedef struct kernel_stat kstat_t;
 388#      else
 389typedef struct kernel_stat64 kstat_t;
 390#      endif
 391// Undefine compatibility macros from <sys/stat.h>
 392// so that they would not clash with the kernel_stat
 393// st_[a|m|c]time fields
 394#      if !SANITIZER_GO
 395#        undef st_atime
 396#        undef st_mtime
 397#        undef st_ctime
 398#      endif
 399#      if defined(SANITIZER_ANDROID)
 400// Bionic sys/stat.h defines additional macros
 401// for compatibility with the old NDKs and
 402// they clash with the kernel_stat structure
 403// st_[a|m|c]time_nsec fields.
 404#        undef st_atime_nsec
 405#        undef st_mtime_nsec
 406#        undef st_ctime_nsec
 407#      endif
 408static void kernel_stat_to_stat(kstat_t *in, struct stat *out) {
 409  internal_memset(out, 0, sizeof(*out));
 410  out->st_dev = in->st_dev;
 411  out->st_ino = in->st_ino;
 412  out->st_mode = in->st_mode;
 413  out->st_nlink = in->st_nlink;
 414  out->st_uid = in->st_uid;
 415  out->st_gid = in->st_gid;
 416  out->st_rdev = in->st_rdev;
 417  out->st_size = in->st_size;
 418  out->st_blksize = in->st_blksize;
 419  out->st_blocks = in->st_blocks;
 420#      if defined(__USE_MISC) || defined(__USE_XOPEN2K8) || \
 421          defined(SANITIZER_ANDROID)
 422  out->st_atim.tv_sec = in->st_atime;
 423  out->st_atim.tv_nsec = in->st_atime_nsec;
 424  out->st_mtim.tv_sec = in->st_mtime;
 425  out->st_mtim.tv_nsec = in->st_mtime_nsec;
 426  out->st_ctim.tv_sec = in->st_ctime;
 427  out->st_ctim.tv_nsec = in->st_ctime_nsec;
 428#      else
 429  out->st_atime = in->st_atime;
 430  out->st_atimensec = in->st_atime_nsec;
 431  out->st_mtime = in->st_mtime;
 432  out->st_mtimensec = in->st_mtime_nsec;
 433  out->st_ctime = in->st_ctime;
 434  out->st_atimensec = in->st_ctime_nsec;
 435#      endif
 436}
 437#    endif
 438
 439uptr internal_stat(const char *path, void *buf) {
 440#    if SANITIZER_FREEBSD
 441  return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0);
 442#    elif SANITIZER_LINUX
 443#      if defined(__loongarch__)
 444  struct statx bufx;
 445  int res = internal_syscall(SYSCALL(statx), AT_FDCWD, (uptr)path,
 446                             AT_NO_AUTOMOUNT, STATX_BASIC_STATS, (uptr)&bufx);
 447  statx_to_stat(&bufx, (struct stat *)buf);
 448  return res;
 449#      elif (                                                                 \
 450          SANITIZER_WORDSIZE == 64 || SANITIZER_X32 ||                        \
 451          (defined(__mips__) && defined(_ABIN32) && _MIPS_SIM == _ABIN32)) && \
 452          !SANITIZER_SPARC
 453  return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
 454                          0);
 455#      elif SANITIZER_SPARC64
 456  kstat_t buf64;
 457  int res = internal_syscall(SYSCALL(fstatat64), AT_FDCWD, (uptr)path,
 458                             (uptr)&buf64, 0);
 459  kernel_stat_to_stat(&buf64, (struct stat *)buf);
 460  return res;
 461#      else
 462  struct stat64 buf64;
 463  int res = internal_syscall(SYSCALL(fstatat64), AT_FDCWD, (uptr)path,
 464                             (uptr)&buf64, 0);
 465  stat64_to_stat(&buf64, (struct stat *)buf);
 466  return res;
 467#      endif
 468#    else
 469  struct stat64 buf64;
 470  int res = internal_syscall(SYSCALL(stat64), path, &buf64);
 471  stat64_to_stat(&buf64, (struct stat *)buf);
 472  return res;
 473#    endif
 474}
 475
 476uptr internal_lstat(const char *path, void *buf) {
 477#    if SANITIZER_FREEBSD
 478  return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf,
 479                          AT_SYMLINK_NOFOLLOW);
 480#    elif SANITIZER_LINUX
 481#      if defined(__loongarch__)
 482  struct statx bufx;
 483  int res = internal_syscall(SYSCALL(statx), AT_FDCWD, (uptr)path,
 484                             AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT,
 485                             STATX_BASIC_STATS, (uptr)&bufx);
 486  statx_to_stat(&bufx, (struct stat *)buf);
 487  return res;
 488#      elif (                                                                 \
 489          defined(_LP64) || SANITIZER_X32 ||                                  \
 490          (defined(__mips__) && defined(_ABIN32) && _MIPS_SIM == _ABIN32)) && \
 491          !SANITIZER_SPARC
 492  return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
 493                          AT_SYMLINK_NOFOLLOW);
 494#      elif SANITIZER_SPARC64
 495  kstat_t buf64;
 496  int res = internal_syscall(SYSCALL(fstatat64), AT_FDCWD, (uptr)path,
 497                             (uptr)&buf64, AT_SYMLINK_NOFOLLOW);
 498  kernel_stat_to_stat(&buf64, (struct stat *)buf);
 499  return res;
 500#      else
 501  struct stat64 buf64;
 502  int res = internal_syscall(SYSCALL(fstatat64), AT_FDCWD, (uptr)path,
 503                             (uptr)&buf64, AT_SYMLINK_NOFOLLOW);
 504  stat64_to_stat(&buf64, (struct stat *)buf);
 505  return res;
 506#      endif
 507#    else
 508  struct stat64 buf64;
 509  int res = internal_syscall(SYSCALL(lstat64), path, &buf64);
 510  stat64_to_stat(&buf64, (struct stat *)buf);
 511  return res;
 512#    endif
 513}
 514
 515uptr internal_fstat(fd_t fd, void *buf) {
 516#    if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
 517#      if SANITIZER_MIPS64
 518  // For mips64, fstat syscall fills buffer in the format of kernel_stat
 519  kstat_t kbuf;
 520  int res = internal_syscall(SYSCALL(fstat), fd, &kbuf);
 521  kernel_stat_to_stat(&kbuf, (struct stat *)buf);
 522  return res;
 523#      elif SANITIZER_LINUX && SANITIZER_SPARC64
 524  // For sparc64, fstat64 syscall fills buffer in the format of kernel_stat64
 525  kstat_t kbuf;
 526  int res = internal_syscall(SYSCALL(fstat64), fd, &kbuf);
 527  kernel_stat_to_stat(&kbuf, (struct stat *)buf);
 528  return res;
 529#      elif SANITIZER_LINUX && defined(__loongarch__)
 530  struct statx bufx;
 531  int res = internal_syscall(SYSCALL(statx), fd, "", AT_EMPTY_PATH,
 532                             STATX_BASIC_STATS, (uptr)&bufx);
 533  statx_to_stat(&bufx, (struct stat *)buf);
 534  return res;
 535#      else
 536  return internal_syscall(SYSCALL(fstat), fd, (uptr)buf);
 537#      endif
 538#    else
 539  struct stat64 buf64;
 540  int res = internal_syscall(SYSCALL(fstat64), fd, &buf64);
 541  stat64_to_stat(&buf64, (struct stat *)buf);
 542  return res;
 543#    endif
 544}
 545
 546uptr internal_filesize(fd_t fd) {
 547  struct stat st;
 548  if (internal_fstat(fd, &st))
 549    return -1;
 550  return (uptr)st.st_size;
 551}
 552
 553uptr internal_dup(int oldfd) { return internal_syscall(SYSCALL(dup), oldfd); }
 554
 555uptr internal_dup2(int oldfd, int newfd) {
 556#    if SANITIZER_LINUX
 557  return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0);
 558#    else
 559  return internal_syscall(SYSCALL(dup2), oldfd, newfd);
 560#    endif
 561}
 562
 563uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
 564#    if SANITIZER_LINUX
 565  return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf,
 566                          bufsize);
 567#    else
 568  return internal_syscall(SYSCALL(readlink), (uptr)path, (uptr)buf, bufsize);
 569#    endif
 570}
 571
 572uptr internal_unlink(const char *path) {
 573#    if SANITIZER_LINUX
 574  return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0);
 575#    else
 576  return internal_syscall(SYSCALL(unlink), (uptr)path);
 577#    endif
 578}
 579
 580uptr internal_rename(const char *oldpath, const char *newpath) {
 581#    if (defined(__riscv) || defined(__loongarch__)) && defined(__linux__)
 582  return internal_syscall(SYSCALL(renameat2), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
 583                          (uptr)newpath, 0);
 584#    elif SANITIZER_LINUX
 585  return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
 586                          (uptr)newpath);
 587#    else
 588  return internal_syscall(SYSCALL(rename), (uptr)oldpath, (uptr)newpath);
 589#    endif
 590}
 591
 592uptr internal_sched_yield() { return internal_syscall(SYSCALL(sched_yield)); }
 593
 594void internal_usleep(u64 useconds) {
 595  struct timespec ts;
 596  ts.tv_sec = useconds / 1000000;
 597  ts.tv_nsec = (useconds % 1000000) * 1000;
 598  internal_syscall(SYSCALL(nanosleep), &ts, &ts);
 599}
 600
 601uptr internal_execve(const char *filename, char *const argv[],
 602                     char *const envp[]) {
 603  return internal_syscall(SYSCALL(execve), (uptr)filename, (uptr)argv,
 604                          (uptr)envp);
 605}
 606#  endif  // !SANITIZER_SOLARIS && !SANITIZER_NETBSD && !SANITIZER_HAIKU
 607
 608#  if !SANITIZER_NETBSD && !SANITIZER_HAIKU
 609void internal__exit(int exitcode) {
 610#    if SANITIZER_FREEBSD || SANITIZER_SOLARIS
 611  internal_syscall(SYSCALL(exit), exitcode);
 612#    else
 613  internal_syscall(SYSCALL(exit_group), exitcode);
 614#    endif
 615  Die();  // Unreachable.
 616}
 617#  endif  // !SANITIZER_NETBSD && !SANITIZER_HAIKU
 618
 619// ----------------- sanitizer_common.h
 620bool FileExists(const char *filename) {
 621  if (ShouldMockFailureToOpen(filename))
 622    return false;
 623  struct stat st;
 624  if (internal_stat(filename, &st))
 625    return false;
 626  // Sanity check: filename is a regular file.
 627  return S_ISREG(st.st_mode);
 628}
 629
 630bool DirExists(const char *path) {
 631  struct stat st;
 632  if (internal_stat(path, &st))
 633    return false;
 634  return S_ISDIR(st.st_mode);
 635}
 636
 637#  if !SANITIZER_NETBSD
 638tid_t GetTid() {
 639#    if SANITIZER_FREEBSD
 640  long Tid;
 641  thr_self(&Tid);
 642  return Tid;
 643#    elif SANITIZER_SOLARIS
 644  return thr_self();
 645#    elif SANITIZER_HAIKU
 646  return find_thread(NULL);
 647#    else
 648  return internal_syscall(SYSCALL(gettid));
 649#    endif
 650}
 651
 652int TgKill(pid_t pid, tid_t tid, int sig) {
 653#    if SANITIZER_LINUX
 654  return internal_syscall(SYSCALL(tgkill), pid, tid, sig);
 655#    elif SANITIZER_FREEBSD
 656  return internal_syscall(SYSCALL(thr_kill2), pid, tid, sig);
 657#    elif SANITIZER_SOLARIS
 658  (void)pid;
 659  errno = thr_kill(tid, sig);
 660  // TgKill is expected to return -1 on error, not an errno.
 661  return errno != 0 ? -1 : 0;
 662#    elif SANITIZER_HAIKU
 663  return kill_thread(tid);
 664#    endif
 665}
 666#  endif
 667
 668#  if SANITIZER_GLIBC
 669u64 NanoTime() {
 670  kernel_timeval tv;
 671  internal_memset(&tv, 0, sizeof(tv));
 672  internal_syscall(SYSCALL(gettimeofday), &tv, 0);
 673  return (u64)tv.tv_sec * 1000 * 1000 * 1000 + tv.tv_usec * 1000;
 674}
 675// Used by real_clock_gettime.
 676uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp) {
 677  return internal_syscall(SYSCALL(clock_gettime), clk_id, tp);
 678}
 679#  elif !SANITIZER_SOLARIS && !SANITIZER_NETBSD
 680u64 NanoTime() {
 681  struct timespec ts;
 682  clock_gettime(CLOCK_REALTIME, &ts);
 683  return (u64)ts.tv_sec * 1000 * 1000 * 1000 + ts.tv_nsec;
 684}
 685#  endif
 686
 687// Like getenv, but reads env directly from /proc (on Linux) or parses the
 688// 'environ' array (on some others) and does not use libc. This function
 689// should be called first inside __asan_init.
 690const char *GetEnv(const char *name) {
 691#  if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_SOLARIS || \
 692      SANITIZER_HAIKU
 693  if (::environ != 0) {
 694    uptr NameLen = internal_strlen(name);
 695    for (char **Env = ::environ; *Env != 0; Env++) {
 696      if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
 697        return (*Env) + NameLen + 1;
 698    }
 699  }
 700  return 0;  // Not found.
 701#  elif SANITIZER_LINUX
 702  static char *environ;
 703  static uptr len;
 704  static bool inited;
 705  if (!inited) {
 706    inited = true;
 707    uptr environ_size;
 708    if (!ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, &len))
 709      environ = nullptr;
 710  }
 711  if (!environ || len == 0)
 712    return nullptr;
 713  uptr namelen = internal_strlen(name);
 714  const char *p = environ;
 715  while (*p != '\0') {  // will happen at the \0\0 that terminates the buffer
 716    // proc file has the format NAME=value\0NAME=value\0NAME=value\0...
 717    const char *endp = (char *)internal_memchr(p, '\0', len - (p - environ));
 718    if (!endp)  // this entry isn't NUL terminated
 719      return nullptr;
 720    else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=')  // Match.
 721      return p + namelen + 1;  // point after =
 722    p = endp + 1;
 723  }
 724  return nullptr;  // Not found.
 725#  else
 726#    error "Unsupported platform"
 727#  endif
 728}
 729
 730#  if !SANITIZER_HAIKU && !SANITIZER_FREEBSD && !SANITIZER_NETBSD && \
 731      !SANITIZER_GO
 732extern "C" {
 733SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end;
 734}
 735#  endif
 736
 737#  if !SANITIZER_HAIKU && !SANITIZER_FREEBSD && !SANITIZER_NETBSD
 738static void ReadNullSepFileToArray(const char *path, char ***arr,
 739                                   int arr_size) {
 740  char *buff;
 741  uptr buff_size;
 742  uptr buff_len;
 743  *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray");
 744  if (!ReadFileToBuffer(path, &buff, &buff_size, &buff_len, 1024 * 1024)) {
 745    (*arr)[0] = nullptr;
 746    return;
 747  }
 748  (*arr)[0] = buff;
 749  int count, i;
 750  for (count = 1, i = 1;; i++) {
 751    if (buff[i] == 0) {
 752      if (buff[i + 1] == 0)
 753        break;
 754      (*arr)[count] = &buff[i + 1];
 755      CHECK_LE(count, arr_size - 1);  // FIXME: make this more flexible.
 756      count++;
 757    }
 758  }
 759  (*arr)[count] = nullptr;
 760}
 761#  endif
 762
 763static void GetArgsAndEnv(char ***argv, char ***envp) {
 764#  if SANITIZER_HAIKU
 765  *argv = __libc_argv;
 766  *envp = environ;
 767#  elif SANITIZER_FREEBSD
 768  // On FreeBSD, retrieving the argument and environment arrays is done via the
 769  // kern.ps_strings sysctl, which returns a pointer to a structure containing
 770  // this information. See also <sys/exec.h>.
 771  ps_strings *pss;
 772  uptr sz = sizeof(pss);
 773  if (internal_sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) {
 774    Printf("sysctl kern.ps_strings failed\n");
 775    Die();
 776  }
 777  *argv = pss->ps_argvstr;
 778  *envp = pss->ps_envstr;
 779#  elif SANITIZER_NETBSD
 780  *argv = __ps_strings->ps_argvstr;
 781  *envp = __ps_strings->ps_envstr;
 782#  else  // SANITIZER_FREEBSD
 783#    if !SANITIZER_GO
 784  if (&__libc_stack_end) {
 785    uptr *stack_end = (uptr *)__libc_stack_end;
 786    // Linux/sparc64 needs an adjustment, cf. glibc
 787    // sysdeps/sparc/sparc{32,64}/dl-machine.h (DL_STACK_END).
 788#      if SANITIZER_LINUX && defined(__sparc__)
 789    stack_end = &stack_end[16];
 790#      endif
 791    // Normally argc can be obtained from *stack_end, however, on ARM glibc's
 792    // _start clobbers it:
 793    // https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/arm/start.S;hb=refs/heads/release/2.31/master#l75
 794    // Do not special-case ARM and infer argc from argv everywhere.
 795    int argc = 0;
 796    while (stack_end[argc + 1]) argc++;
 797    *argv = (char **)(stack_end + 1);
 798    *envp = (char **)(stack_end + argc + 2);
 799  } else {
 800#    endif  // !SANITIZER_GO
 801    static const int kMaxArgv = 2000, kMaxEnvp = 2000;
 802    ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv);
 803    ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp);
 804#    if !SANITIZER_GO
 805  }
 806#    endif  // !SANITIZER_GO
 807#  endif    // SANITIZER_HAIKU
 808}
 809
 810char **GetArgv() {
 811  char **argv, **envp;
 812  GetArgsAndEnv(&argv, &envp);
 813  return argv;
 814}
 815
 816char **GetEnviron() {
 817  char **argv, **envp;
 818  GetArgsAndEnv(&argv, &envp);
 819  return envp;
 820}
 821
 822#  if !SANITIZER_SOLARIS
 823void FutexWait(atomic_uint32_t *p, u32 cmp) {
 824#    if SANITIZER_FREEBSD
 825  _umtx_op(p, UMTX_OP_WAIT_UINT, cmp, 0, 0);
 826#    elif SANITIZER_NETBSD || SANITIZER_HAIKU
 827  sched_yield(); /* No userspace futex-like synchronization */
 828#    else
 829  internal_syscall(SYSCALL(futex), (uptr)p, FUTEX_WAIT_PRIVATE, cmp, 0, 0, 0);
 830#    endif
 831}
 832
 833void FutexWake(atomic_uint32_t *p, u32 count) {
 834#    if SANITIZER_FREEBSD
 835  _umtx_op(p, UMTX_OP_WAKE, count, 0, 0);
 836#    elif SANITIZER_NETBSD || SANITIZER_HAIKU
 837  /* No userspace futex-like synchronization */
 838#    else
 839  internal_syscall(SYSCALL(futex), (uptr)p, FUTEX_WAKE_PRIVATE, count, 0, 0, 0);
 840#    endif
 841}
 842
 843#  endif  // !SANITIZER_SOLARIS
 844
 845// ----------------- sanitizer_linux.h
 846// The actual size of this structure is specified by d_reclen.
 847// Note that getdents64 uses a different structure format. We only provide the
 848// 32-bit syscall here.
 849#  if SANITIZER_NETBSD
 850// Not used
 851#  else
 852struct linux_dirent {
 853#    if SANITIZER_X32 || SANITIZER_LINUX
 854  u64 d_ino;
 855  u64 d_off;
 856#    else
 857  unsigned long d_ino;
 858  unsigned long d_off;
 859#    endif
 860  unsigned short d_reclen;
 861#    if SANITIZER_LINUX
 862  unsigned char d_type;
 863#    endif
 864  char d_name[256];
 865};
 866#  endif
 867
 868#  if !SANITIZER_SOLARIS && !SANITIZER_NETBSD && !SANITIZER_HAIKU
 869// Syscall wrappers.
 870uptr internal_ptrace(int request, int pid, void *addr, void *data) {
 871  return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr,
 872                          (uptr)data);
 873}
 874
 875uptr internal_waitpid(int pid, int *status, int options) {
 876  return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options,
 877                          0 /* rusage */);
 878}
 879
 880uptr internal_getpid() { return internal_syscall(SYSCALL(getpid)); }
 881
 882uptr internal_getppid() { return internal_syscall(SYSCALL(getppid)); }
 883
 884int internal_dlinfo(void *handle, int request, void *p) {
 885#    if SANITIZER_FREEBSD
 886  return dlinfo(handle, request, p);
 887#    else
 888  UNIMPLEMENTED();
 889#    endif
 890}
 891
 892uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
 893#    if SANITIZER_FREEBSD
 894  return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL);
 895#    elif SANITIZER_LINUX
 896  return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count);
 897#    else
 898  return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count);
 899#    endif
 900}
 901
 902uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
 903  return internal_syscall(SYSCALL(lseek), fd, offset, whence);
 904}
 905
 906#    if SANITIZER_LINUX
 907uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) {
 908  return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5);
 909}
 910#      if defined(__x86_64__)
 911#        include <asm/unistd_64.h>
 912// Currently internal_arch_prctl() is only needed on x86_64.
 913uptr internal_arch_prctl(int option, uptr arg2) {
 914  return internal_syscall(__NR_arch_prctl, option, arg2);
 915}
 916#      endif
 917#    endif
 918
 919uptr internal_sigaltstack(const void *ss, void *oss) {
 920  return internal_syscall(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss);
 921}
 922
 923extern "C" pid_t __fork(void);
 924
 925int internal_fork() {
 926#    if SANITIZER_LINUX
 927#      if SANITIZER_S390
 928  return internal_syscall(SYSCALL(clone), 0, SIGCHLD);
 929#      elif SANITIZER_SPARC
 930  // The clone syscall interface on SPARC differs massively from the rest,
 931  // so fall back to __fork.
 932  return __fork();
 933#      else
 934  return internal_syscall(SYSCALL(clone), SIGCHLD, 0);
 935#      endif
 936#    else
 937  return internal_syscall(SYSCALL(fork));
 938#    endif
 939}
 940
 941#    if SANITIZER_FREEBSD
 942int internal_sigaction(int signum, const void *act, void *oldact) {
 943  /* zig patch: use direct syscall for freebsd mmap */
 944  return internal_syscall(SYSCALL(sigaction), signum, (uptr)act, (uptr)oldact);
 945}
 946
 947int internal_sysctl(const int *name, unsigned int namelen, void *oldp,
 948                    uptr *oldlenp, const void *newp, uptr newlen) {
 949  return internal_syscall(SYSCALL(__sysctl), name, namelen, oldp,
 950                          (size_t *)oldlenp, newp, (size_t)newlen);
 951}
 952
 953int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp,
 954                          const void *newp, uptr newlen) {
 955  // Note: this function can be called during startup, so we need to avoid
 956  // calling any interceptable functions. On FreeBSD >= 1300045 sysctlbyname()
 957  // is a real syscall, but for older versions it calls sysctlnametomib()
 958  // followed by sysctl(). To avoid calling the intercepted version and
 959  // asserting if this happens during startup, call the real sysctlnametomib()
 960  // followed by internal_sysctl() if the syscall is not available.
 961#      ifdef SYS___sysctlbyname
 962  return internal_syscall(SYSCALL(__sysctlbyname), sname,
 963                          internal_strlen(sname), oldp, (size_t *)oldlenp, newp,
 964                          (size_t)newlen);
 965#      else
 966  static decltype(sysctlnametomib) *real_sysctlnametomib = nullptr;
 967  if (!real_sysctlnametomib)
 968    real_sysctlnametomib =
 969        (decltype(sysctlnametomib) *)dlsym(RTLD_NEXT, "sysctlnametomib");
 970  CHECK(real_sysctlnametomib);
 971
 972  int oid[CTL_MAXNAME];
 973  size_t len = CTL_MAXNAME;
 974  if (real_sysctlnametomib(sname, oid, &len) == -1)
 975    return (-1);
 976  return internal_sysctl(oid, len, oldp, oldlenp, newp, newlen);
 977#      endif
 978}
 979#    endif
 980
 981#    if SANITIZER_LINUX
 982#      define SA_RESTORER 0x04000000
 983// Doesn't set sa_restorer if the caller did not set it, so use with caution
 984//(see below).
 985int internal_sigaction_norestorer(int signum, const void *act, void *oldact) {
 986  __sanitizer_kernel_sigaction_t k_act, k_oldact;
 987  internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t));
 988  internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t));
 989  const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act;
 990  __sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact;
 991  if (u_act) {
 992    k_act.handler = u_act->handler;
 993    k_act.sigaction = u_act->sigaction;
 994    internal_memcpy(&k_act.sa_mask, &u_act->sa_mask,
 995                    sizeof(__sanitizer_kernel_sigset_t));
 996    // Without SA_RESTORER kernel ignores the calls (probably returns EINVAL).
 997    k_act.sa_flags = u_act->sa_flags | SA_RESTORER;
 998    // FIXME: most often sa_restorer is unset, however the kernel requires it
 999    // to point to a valid signal restorer that calls the rt_sigreturn syscall.
1000    // If sa_restorer passed to the kernel is NULL, the program may crash upon
1001    // signal delivery or fail to unwind the stack in the signal handler.
1002    // libc implementation of sigaction() passes its own restorer to
1003    // rt_sigaction, so we need to do the same (we'll need to reimplement the
1004    // restorers; for x86_64 the restorer address can be obtained from
1005    // oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact).
1006#      if !SANITIZER_ANDROID || !SANITIZER_MIPS32
1007    k_act.sa_restorer = u_act->sa_restorer;
1008#      endif
1009  }
1010
1011  uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum,
1012                                 (uptr)(u_act ? &k_act : nullptr),
1013                                 (uptr)(u_oldact ? &k_oldact : nullptr),
1014                                 (uptr)sizeof(__sanitizer_kernel_sigset_t));
1015
1016  if ((result == 0) && u_oldact) {
1017    u_oldact->handler = k_oldact.handler;
1018    u_oldact->sigaction = k_oldact.sigaction;
1019    internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask,
1020                    sizeof(__sanitizer_kernel_sigset_t));
1021    u_oldact->sa_flags = k_oldact.sa_flags;
1022#      if !SANITIZER_ANDROID || !SANITIZER_MIPS32
1023    u_oldact->sa_restorer = k_oldact.sa_restorer;
1024#      endif
1025  }
1026  return result;
1027}
1028#    endif  // SANITIZER_LINUX
1029
1030uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
1031                          __sanitizer_sigset_t *oldset) {
1032#    if SANITIZER_FREEBSD
1033  return internal_syscall(SYSCALL(sigprocmask), how, set, oldset);
1034#    else
1035  __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
1036  __sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset;
1037  return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how, (uptr)k_set,
1038                          (uptr)k_oldset, sizeof(__sanitizer_kernel_sigset_t));
1039#    endif
1040}
1041
1042void internal_sigfillset(__sanitizer_sigset_t *set) {
1043  internal_memset(set, 0xff, sizeof(*set));
1044}
1045
1046void internal_sigemptyset(__sanitizer_sigset_t *set) {
1047  internal_memset(set, 0, sizeof(*set));
1048}
1049
1050#    if SANITIZER_LINUX
1051void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
1052  signum -= 1;
1053  CHECK_GE(signum, 0);
1054  CHECK_LT(signum, sizeof(*set) * 8);
1055  __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
1056  const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
1057  const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
1058  k_set->sig[idx] &= ~((uptr)1 << bit);
1059}
1060
1061bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
1062  signum -= 1;
1063  CHECK_GE(signum, 0);
1064  CHECK_LT(signum, sizeof(*set) * 8);
1065  __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
1066  const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
1067  const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
1068  return k_set->sig[idx] & ((uptr)1 << bit);
1069}
1070#    elif SANITIZER_FREEBSD
1071uptr internal_procctl(int type, int id, int cmd, void *data) {
1072  return internal_syscall(SYSCALL(procctl), type, id, cmd, data);
1073}
1074
1075void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
1076  sigset_t *rset = reinterpret_cast<sigset_t *>(set);
1077  sigdelset(rset, signum);
1078}
1079
1080bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
1081  sigset_t *rset = reinterpret_cast<sigset_t *>(set);
1082  return sigismember(rset, signum);
1083}
1084#    endif
1085#  endif  // !SANITIZER_SOLARIS
1086
1087#  if !SANITIZER_NETBSD && !SANITIZER_HAIKU
1088// ThreadLister implementation.
1089ThreadLister::ThreadLister(pid_t pid) : buffer_(4096) {
1090  task_path_.AppendF("/proc/%d/task", pid);
1091}
1092
1093ThreadLister::Result ThreadLister::ListThreads(
1094    InternalMmapVector<tid_t> *threads) {
1095  int descriptor = internal_open(task_path_.data(), O_RDONLY | O_DIRECTORY);
1096  if (internal_iserror(descriptor)) {
1097    Report("Can't open %s for reading.\n", task_path_.data());
1098    return Error;
1099  }
1100  auto cleanup = at_scope_exit([&] { internal_close(descriptor); });
1101  threads->clear();
1102
1103  Result result = Ok;
1104  for (bool first_read = true;; first_read = false) {
1105    CHECK_GE(buffer_.size(), 4096);
1106    uptr read = internal_getdents(
1107        descriptor, (struct linux_dirent *)buffer_.data(), buffer_.size());
1108    if (!read)
1109      return result;
1110    if (internal_iserror(read)) {
1111      Report("Can't read directory entries from %s.\n", task_path_.data());
1112      return Error;
1113    }
1114
1115    for (uptr begin = (uptr)buffer_.data(), end = begin + read; begin < end;) {
1116      struct linux_dirent *entry = (struct linux_dirent *)begin;
1117      begin += entry->d_reclen;
1118      if (entry->d_ino == 1) {
1119        // Inode 1 is for bad blocks and also can be a reason for early return.
1120        // Should be emitted if kernel tried to output terminating thread.
1121        // See proc_task_readdir implementation in Linux.
1122        result = Incomplete;
1123      }
1124      if (entry->d_ino && *entry->d_name >= '0' && *entry->d_name <= '9')
1125        threads->push_back(internal_atoll(entry->d_name));
1126    }
1127
1128    // Now we are going to detect short-read or early EOF. In such cases Linux
1129    // can return inconsistent list with missing alive threads.
1130    // Code will just remember that the list can be incomplete but it will
1131    // continue reads to return as much as possible.
1132    if (!first_read) {
1133      // The first one was a short-read by definition.
1134      result = Incomplete;
1135    } else if (read > buffer_.size() - 1024) {
1136      // Read was close to the buffer size. So double the size and assume the
1137      // worst.
1138      buffer_.resize(buffer_.size() * 2);
1139      result = Incomplete;
1140    } else if (!threads->empty() && !IsAlive(threads->back())) {
1141      // Maybe Linux early returned from read on terminated thread (!pid_alive)
1142      // and failed to restore read position.
1143      // See next_tid and proc_task_instantiate in Linux.
1144      result = Incomplete;
1145    }
1146  }
1147}
1148
1149const char *ThreadLister::LoadStatus(tid_t tid) {
1150  status_path_.clear();
1151  status_path_.AppendF("%s/%llu/status", task_path_.data(), tid);
1152  auto cleanup = at_scope_exit([&] {
1153    // Resize back to capacity if it is downsized by `ReadFileToVector`.
1154    buffer_.resize(buffer_.capacity());
1155  });
1156  if (!ReadFileToVector(status_path_.data(), &buffer_) || buffer_.empty())
1157    return nullptr;
1158  buffer_.push_back('\0');
1159  return buffer_.data();
1160}
1161
1162bool ThreadLister::IsAlive(tid_t tid) {
1163  // /proc/%d/task/%d/status uses same call to detect alive threads as
1164  // proc_task_readdir. See task_state implementation in Linux.
1165  static const char kPrefix[] = "\nPPid:";
1166  const char *status = LoadStatus(tid);
1167  if (!status)
1168    return false;
1169  const char *field = internal_strstr(status, kPrefix);
1170  if (!field)
1171    return false;
1172  field += internal_strlen(kPrefix);
1173  return (int)internal_atoll(field) != 0;
1174}
1175
1176#  endif
1177
1178#  if SANITIZER_WORDSIZE == 32
1179// Take care of unusable kernel area in top gigabyte.
1180static uptr GetKernelAreaSize() {
1181#    if SANITIZER_LINUX && !SANITIZER_X32
1182  const uptr gbyte = 1UL << 30;
1183
1184  // Firstly check if there are writable segments
1185  // mapped to top gigabyte (e.g. stack).
1186  MemoryMappingLayout proc_maps(/*cache_enabled*/ true);
1187  if (proc_maps.Error())
1188    return 0;
1189  MemoryMappedSegment segment;
1190  while (proc_maps.Next(&segment)) {
1191    if ((segment.end >= 3 * gbyte) && segment.IsWritable())
1192      return 0;
1193  }
1194
1195#      if !SANITIZER_ANDROID
1196  // Even if nothing is mapped, top Gb may still be accessible
1197  // if we are running on 64-bit kernel.
1198  // Uname may report misleading results if personality type
1199  // is modified (e.g. under schroot) so check this as well.
1200  struct utsname uname_info;
1201  int pers = personality(0xffffffffUL);
1202  if (!(pers & PER_MASK) && internal_uname(&uname_info) == 0 &&
1203      internal_strstr(uname_info.machine, "64"))
1204    return 0;
1205#      endif  // SANITIZER_ANDROID
1206
1207  // Top gigabyte is reserved for kernel.
1208  return gbyte;
1209#    else
1210  return 0;
1211#    endif  // SANITIZER_LINUX && !SANITIZER_X32
1212}
1213#  endif  // SANITIZER_WORDSIZE == 32
1214
1215uptr GetMaxVirtualAddress() {
1216#  if SANITIZER_NETBSD && defined(__x86_64__)
1217  return 0x7f7ffffff000ULL;  // (0x00007f8000000000 - PAGE_SIZE)
1218#  elif SANITIZER_WORDSIZE == 64
1219#    if defined(__powerpc64__) || defined(__aarch64__) || \
1220        defined(__loongarch__) || SANITIZER_RISCV64
1221  // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
1222  // We somehow need to figure out which one we are using now and choose
1223  // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
1224  // Note that with 'ulimit -s unlimited' the stack is moved away from the top
1225  // of the address space, so simply checking the stack address is not enough.
1226  // This should (does) work for both PowerPC64 Endian modes.
1227  // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
1228  // loongarch64 also has multiple address space layouts: default is 47-bit.
1229  // RISC-V 64 also has multiple address space layouts: 39, 48 and 57-bit.
1230  return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
1231#    elif SANITIZER_MIPS64
1232  return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
1233#    elif defined(__s390x__)
1234  return (1ULL << 53) - 1;  // 0x001fffffffffffffUL;
1235#    elif defined(__sparc__)
1236  return ~(uptr)0;
1237#    else
1238  return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
1239#    endif
1240#  else  // SANITIZER_WORDSIZE == 32
1241#    if defined(__s390__)
1242  return (1ULL << 31) - 1;  // 0x7fffffff;
1243#    else
1244  return (1ULL << 32) - 1;  // 0xffffffff;
1245#    endif
1246#  endif  // SANITIZER_WORDSIZE
1247}
1248
1249uptr GetMaxUserVirtualAddress() {
1250  uptr addr = GetMaxVirtualAddress();
1251#  if SANITIZER_WORDSIZE == 32 && !defined(__s390__)
1252  if (!common_flags()->full_address_space)
1253    addr -= GetKernelAreaSize();
1254  CHECK_LT(reinterpret_cast<uptr>(&addr), addr);
1255#  endif
1256  return addr;
1257}
1258
1259#  if !SANITIZER_ANDROID || defined(__aarch64__)
1260uptr GetPageSize() {
1261#    if SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__)) && \
1262        defined(EXEC_PAGESIZE)
1263  return EXEC_PAGESIZE;
1264#    elif SANITIZER_FREEBSD || SANITIZER_NETBSD
1265  // Use sysctl as sysconf can trigger interceptors internally.
1266  int pz = 0;
1267  uptr pzl = sizeof(pz);
1268  int mib[2] = {CTL_HW, HW_PAGESIZE};
1269  int rv = internal_sysctl(mib, 2, &pz, &pzl, nullptr, 0);
1270  CHECK_EQ(rv, 0);
1271  return (uptr)pz;
1272#    elif SANITIZER_USE_GETAUXVAL
1273#      if SANITIZER_ANDROID && __ANDROID_API__ < 35
1274  // The 16 KB page size was introduced in Android 15 (API level 35), while
1275  // earlier versions of Android always used a 4 KB page size.
1276  // We are checking the weak definition of `strerrorname_np` (introduced in API
1277  // level 35) because some earlier API levels crashed when
1278  // `getauxval(AT_PAGESZ)` was called from the `.preinit_array`.
1279  if (!strerrorname_np)
1280    return 4096;
1281#      endif
1282
1283  return getauxval(AT_PAGESZ);
1284#    else
1285  return sysconf(_SC_PAGESIZE);  // EXEC_PAGESIZE may not be trustworthy.
1286#    endif
1287}
1288#  endif
1289
1290uptr ReadBinaryName(/*out*/ char *buf, uptr buf_len) {
1291#  if SANITIZER_HAIKU
1292  int cookie = 0;
1293  image_info info;
1294  const char *argv0 = "<UNKNOWN>";
1295  while (get_next_image_info(B_CURRENT_TEAM, &cookie, &info) == B_OK) {
1296    if (info.type != B_APP_IMAGE)
1297      continue;
1298    argv0 = info.name;
1299    break;
1300  }
1301  internal_strncpy(buf, argv0, buf_len);
1302  return internal_strlen(buf);
1303#  elif SANITIZER_SOLARIS
1304  const char *default_module_name = getexecname();
1305  CHECK_NE(default_module_name, NULL);
1306  return internal_snprintf(buf, buf_len, "%s", default_module_name);
1307#  else
1308#    if SANITIZER_FREEBSD || SANITIZER_NETBSD
1309#      if SANITIZER_FREEBSD
1310  const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
1311#      else
1312  const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
1313#      endif
1314  const char *default_module_name = "kern.proc.pathname";
1315  uptr Size = buf_len;
1316  bool IsErr =
1317      (internal_sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0);
1318  int readlink_error = IsErr ? errno : 0;
1319  uptr module_name_len = Size;
1320#    else
1321  const char *default_module_name = "/proc/self/exe";
1322  uptr module_name_len = internal_readlink(default_module_name, buf, buf_len);
1323  int readlink_error;
1324  bool IsErr = internal_iserror(module_name_len, &readlink_error);
1325#    endif
1326  if (IsErr) {
1327    // We can't read binary name for some reason, assume it's unknown.
1328    Report(
1329        "WARNING: reading executable name failed with errno %d, "
1330        "some stack frames may not be symbolized\n",
1331        readlink_error);
1332    module_name_len =
1333        internal_snprintf(buf, buf_len, "%s", default_module_name);
1334    CHECK_LT(module_name_len, buf_len);
1335  }
1336  return module_name_len;
1337#  endif
1338}
1339
1340uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
1341#  if SANITIZER_LINUX
1342  char *tmpbuf;
1343  uptr tmpsize;
1344  uptr tmplen;
1345  if (ReadFileToBuffer("/proc/self/cmdline", &tmpbuf, &tmpsize, &tmplen,
1346                       1024 * 1024)) {
1347    internal_strncpy(buf, tmpbuf, buf_len);
1348    UnmapOrDie(tmpbuf, tmpsize);
1349    return internal_strlen(buf);
1350  }
1351#  endif
1352  return ReadBinaryName(buf, buf_len);
1353}
1354
1355// Match full names of the form /path/to/base_name{-,.}*
1356bool LibraryNameIs(const char *full_name, const char *base_name) {
1357  const char *name = full_name;
1358  // Strip path.
1359  while (*name != '\0') name++;
1360  while (name > full_name && *name != '/') name--;
1361  if (*name == '/')
1362    name++;
1363  uptr base_name_length = internal_strlen(base_name);
1364  if (internal_strncmp(name, base_name, base_name_length))
1365    return false;
1366  return (name[base_name_length] == '-' || name[base_name_length] == '.');
1367}
1368
1369#  if !SANITIZER_ANDROID && !SANITIZER_HAIKU
1370// Call cb for each region mapped by map.
1371void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) {
1372  CHECK_NE(map, nullptr);
1373#    if !SANITIZER_FREEBSD && !SANITIZER_HAIKU
1374  typedef ElfW(Phdr) Elf_Phdr;
1375  typedef ElfW(Ehdr) Elf_Ehdr;
1376#    endif  // !SANITIZER_FREEBSD
1377  char *base = (char *)map->l_addr;
1378  Elf_Ehdr *ehdr = (Elf_Ehdr *)base;
1379  char *phdrs = base + ehdr->e_phoff;
1380  char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize;
1381
1382  // Find the segment with the minimum base so we can "relocate" the p_vaddr
1383  // fields.  Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC
1384  // objects have a non-zero base.
1385  uptr preferred_base = (uptr)-1;
1386  for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
1387    Elf_Phdr *phdr = (Elf_Phdr *)iter;
1388    if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr)
1389      preferred_base = (uptr)phdr->p_vaddr;
1390  }
1391
1392  // Compute the delta from the real base to get a relocation delta.
1393  sptr delta = (uptr)base - preferred_base;
1394  // Now we can figure out what the loader really mapped.
1395  for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
1396    Elf_Phdr *phdr = (Elf_Phdr *)iter;
1397    if (phdr->p_type == PT_LOAD) {
1398      uptr seg_start = phdr->p_vaddr + delta;
1399      uptr seg_end = seg_start + phdr->p_memsz;
1400      // None of these values are aligned.  We consider the ragged edges of the
1401      // load command as defined, since they are mapped from the file.
1402      seg_start = RoundDownTo(seg_start, GetPageSizeCached());
1403      seg_end = RoundUpTo(seg_end, GetPageSizeCached());
1404      cb((void *)seg_start, seg_end - seg_start);
1405    }
1406  }
1407}
1408#  endif
1409
1410#  if SANITIZER_LINUX
1411#    if defined(__x86_64__)
1412// We cannot use glibc's clone wrapper, because it messes with the child
1413// task's TLS. It writes the PID and TID of the child task to its thread
1414// descriptor, but in our case the child task shares the thread descriptor with
1415// the parent (because we don't know how to allocate a new thread
1416// descriptor to keep glibc happy). So the stock version of clone(), when
1417// used with CLONE_VM, would end up corrupting the parent's thread descriptor.
1418uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1419                    int *parent_tidptr, void *newtls, int *child_tidptr) {
1420  long long res;
1421  if (!fn || !child_stack)
1422    return -EINVAL;
1423  CHECK_EQ(0, (uptr)child_stack % 16);
1424  child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1425  ((unsigned long long *)child_stack)[0] = (uptr)fn;
1426  ((unsigned long long *)child_stack)[1] = (uptr)arg;
1427  register void *r8 __asm__("r8") = newtls;
1428  register int *r10 __asm__("r10") = child_tidptr;
1429  __asm__ __volatile__(
1430      /* %rax = syscall(%rax = SYSCALL(clone),
1431       *                %rdi = flags,
1432       *                %rsi = child_stack,
1433       *                %rdx = parent_tidptr,
1434       *                %r8  = new_tls,
1435       *                %r10 = child_tidptr)
1436       */
1437      "syscall\n"
1438
1439      /* if (%rax != 0)
1440       *   return;
1441       */
1442      "testq  %%rax,%%rax\n"
1443      "jnz    1f\n"
1444
1445      /* In the child. Terminate unwind chain. */
1446      // XXX: We should also terminate the CFI unwind chain
1447      // here. Unfortunately clang 3.2 doesn't support the
1448      // necessary CFI directives, so we skip that part.
1449      "xorq   %%rbp,%%rbp\n"
1450
1451      /* Call "fn(arg)". */
1452      "popq   %%rax\n"
1453      "popq   %%rdi\n"
1454      "call   *%%rax\n"
1455
1456      /* Call _exit(%rax). */
1457      "movq   %%rax,%%rdi\n"
1458      "movq   %2,%%rax\n"
1459      "syscall\n"
1460
1461      /* Return to parent. */
1462      "1:\n"
1463      : "=a"(res)
1464      : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)), "S"(child_stack), "D"(flags),
1465        "d"(parent_tidptr), "r"(r8), "r"(r10)
1466      : "memory", "r11", "rcx");
1467  return res;
1468}
1469#    elif defined(__mips__)
1470uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1471                    int *parent_tidptr, void *newtls, int *child_tidptr) {
1472  long long res;
1473  if (!fn || !child_stack)
1474    return -EINVAL;
1475  CHECK_EQ(0, (uptr)child_stack % 16);
1476  child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1477  ((unsigned long long *)child_stack)[0] = (uptr)fn;
1478  ((unsigned long long *)child_stack)[1] = (uptr)arg;
1479  register void *a3 __asm__("$7") = newtls;
1480  register int *a4 __asm__("$8") = child_tidptr;
1481  // We don't have proper CFI directives here because it requires alot of code
1482  // for very marginal benefits.
1483  __asm__ __volatile__(
1484      /* $v0 = syscall($v0 = __NR_clone,
1485       * $a0 = flags,
1486       * $a1 = child_stack,
1487       * $a2 = parent_tidptr,
1488       * $a3 = new_tls,
1489       * $a4 = child_tidptr)
1490       */
1491      ".cprestore 16;\n"
1492      "move $4,%1;\n"
1493      "move $5,%2;\n"
1494      "move $6,%3;\n"
1495      "move $7,%4;\n"
1496  /* Store the fifth argument on stack
1497   * if we are using 32-bit abi.
1498   */
1499#      if SANITIZER_WORDSIZE == 32
1500      "lw %5,16($29);\n"
1501#      else
1502      "move $8,%5;\n"
1503#      endif
1504      "li $2,%6;\n"
1505      "syscall;\n"
1506
1507      /* if ($v0 != 0)
1508       * return;
1509       */
1510      "bnez $2,1f;\n"
1511
1512  /* Call "fn(arg)". */
1513#      if SANITIZER_WORDSIZE == 32
1514#        ifdef __BIG_ENDIAN__
1515      "lw $25,4($29);\n"
1516      "lw $4,12($29);\n"
1517#        else
1518      "lw $25,0($29);\n"
1519      "lw $4,8($29);\n"
1520#        endif
1521#      else
1522      "ld $25,0($29);\n"
1523      "ld $4,8($29);\n"
1524#      endif
1525      "jal $25;\n"
1526
1527      /* Call _exit($v0). */
1528      "move $4,$2;\n"
1529      "li $2,%7;\n"
1530      "syscall;\n"
1531
1532      /* Return to parent. */
1533      "1:\n"
1534      : "=r"(res)
1535      : "r"(flags), "r"(child_stack), "r"(parent_tidptr), "r"(a3), "r"(a4),
1536        "i"(__NR_clone), "i"(__NR_exit)
1537      : "memory", "$29");
1538  return res;
1539}
1540#    elif SANITIZER_RISCV64
1541uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1542                    int *parent_tidptr, void *newtls, int *child_tidptr) {
1543  if (!fn || !child_stack)
1544    return -EINVAL;
1545
1546  CHECK_EQ(0, (uptr)child_stack % 16);
1547
1548  register int res __asm__("a0");
1549  register int __flags __asm__("a0") = flags;
1550  register void *__stack __asm__("a1") = child_stack;
1551  register int *__ptid __asm__("a2") = parent_tidptr;
1552  register void *__tls __asm__("a3") = newtls;
1553  register int *__ctid __asm__("a4") = child_tidptr;
1554  register int (*__fn)(void *) __asm__("a5") = fn;
1555  register void *__arg __asm__("a6") = arg;
1556  register int nr_clone __asm__("a7") = __NR_clone;
1557
1558  __asm__ __volatile__(
1559      "ecall\n"
1560
1561      /* if (a0 != 0)
1562       *   return a0;
1563       */
1564      "bnez a0, 1f\n"
1565
1566      // In the child, now. Call "fn(arg)".
1567      "mv a0, a6\n"
1568      "jalr a5\n"
1569
1570      // Call _exit(a0).
1571      "addi a7, zero, %9\n"
1572      "ecall\n"
1573      "1:\n"
1574
1575      : "=r"(res)
1576      : "0"(__flags), "r"(__stack), "r"(__ptid), "r"(__tls), "r"(__ctid),
1577        "r"(__fn), "r"(__arg), "r"(nr_clone), "i"(__NR_exit)
1578      : "memory");
1579  return res;
1580}
1581#    elif defined(__aarch64__)
1582uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1583                    int *parent_tidptr, void *newtls, int *child_tidptr) {
1584  register long long res __asm__("x0");
1585  if (!fn || !child_stack)
1586    return -EINVAL;
1587  CHECK_EQ(0, (uptr)child_stack % 16);
1588  child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1589  ((unsigned long long *)child_stack)[0] = (uptr)fn;
1590  ((unsigned long long *)child_stack)[1] = (uptr)arg;
1591
1592  register int (*__fn)(void *) __asm__("x0") = fn;
1593  register void *__stack __asm__("x1") = child_stack;
1594  register int __flags __asm__("x2") = flags;
1595  register void *__arg __asm__("x3") = arg;
1596  register int *__ptid __asm__("x4") = parent_tidptr;
1597  register void *__tls __asm__("x5") = newtls;
1598  register int *__ctid __asm__("x6") = child_tidptr;
1599
1600  __asm__ __volatile__(
1601      "mov x0,x2\n" /* flags  */
1602      "mov x2,x4\n" /* ptid  */
1603      "mov x3,x5\n" /* tls  */
1604      "mov x4,x6\n" /* ctid  */
1605      "mov x8,%9\n" /* clone  */
1606
1607      "svc 0x0\n"
1608
1609      /* if (%r0 != 0)
1610       *   return %r0;
1611       */
1612      "cmp x0, #0\n"
1613      "bne 1f\n"
1614
1615      /* In the child, now. Call "fn(arg)". */
1616      "ldp x1, x0, [sp], #16\n"
1617      "blr x1\n"
1618
1619      /* Call _exit(%r0).  */
1620      "mov x8, %10\n"
1621      "svc 0x0\n"
1622      "1:\n"
1623
1624      : "=r"(res)
1625      : "i"(-EINVAL), "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg),
1626        "r"(__ptid), "r"(__tls), "r"(__ctid), "i"(__NR_clone), "i"(__NR_exit)
1627      : "x30", "memory");
1628  return res;
1629}
1630#    elif SANITIZER_LOONGARCH64
1631uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1632                    int *parent_tidptr, void *newtls, int *child_tidptr) {
1633  if (!fn || !child_stack)
1634    return -EINVAL;
1635
1636  CHECK_EQ(0, (uptr)child_stack % 16);
1637
1638  register int res __asm__("$a0");
1639  register int __flags __asm__("$a0") = flags;
1640  register void *__stack __asm__("$a1") = child_stack;
1641  register int *__ptid __asm__("$a2") = parent_tidptr;
1642  register int *__ctid __asm__("$a3") = child_tidptr;
1643  register void *__tls __asm__("$a4") = newtls;
1644  register int (*__fn)(void *) __asm__("$a5") = fn;
1645  register void *__arg __asm__("$a6") = arg;
1646  register int nr_clone __asm__("$a7") = __NR_clone;
1647
1648  __asm__ __volatile__(
1649      "syscall 0\n"
1650
1651      // if ($a0 != 0)
1652      //   return $a0;
1653      "bnez $a0, 1f\n"
1654
1655      // In the child, now. Call "fn(arg)".
1656      "move $a0, $a6\n"
1657      "jirl $ra, $a5, 0\n"
1658
1659      // Call _exit($a0).
1660      "addi.d $a7, $zero, %9\n"
1661      "syscall 0\n"
1662
1663      "1:\n"
1664
1665      : "=r"(res)
1666      : "0"(__flags), "r"(__stack), "r"(__ptid), "r"(__ctid), "r"(__tls),
1667        "r"(__fn), "r"(__arg), "r"(nr_clone), "i"(__NR_exit)
1668      : "memory", "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7",
1669        "$t8");
1670  return res;
1671}
1672#    elif defined(__powerpc64__)
1673uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1674                    int *parent_tidptr, void *newtls, int *child_tidptr) {
1675  long long res;
1676// Stack frame structure.
1677#      if SANITIZER_PPC64V1
1678  //   Back chain == 0        (SP + 112)
1679  // Frame (112 bytes):
1680  //   Parameter save area    (SP + 48), 8 doublewords
1681  //   TOC save area          (SP + 40)
1682  //   Link editor doubleword (SP + 32)
1683  //   Compiler doubleword    (SP + 24)
1684  //   LR save area           (SP + 16)
1685  //   CR save area           (SP + 8)
1686  //   Back chain             (SP + 0)
1687#        define FRAME_SIZE 112
1688#        define FRAME_TOC_SAVE_OFFSET 40
1689#      elif SANITIZER_PPC64V2
1690  //   Back chain == 0        (SP + 32)
1691  // Frame (32 bytes):
1692  //   TOC save area          (SP + 24)
1693  //   LR save area           (SP + 16)
1694  //   CR save area           (SP + 8)
1695  //   Back chain             (SP + 0)
1696#        define FRAME_SIZE 32
1697#        define FRAME_TOC_SAVE_OFFSET 24
1698#      else
1699#        error "Unsupported PPC64 ABI"
1700#      endif
1701  if (!fn || !child_stack)
1702    return -EINVAL;
1703  CHECK_EQ(0, (uptr)child_stack % 16);
1704
1705  register int (*__fn)(void *) __asm__("r3") = fn;
1706  register void *__cstack __asm__("r4") = child_stack;
1707  register int __flags __asm__("r5") = flags;
1708  register void *__arg __asm__("r6") = arg;
1709  register int *__ptidptr __asm__("r7") = parent_tidptr;
1710  register void *__newtls __asm__("r8") = newtls;
1711  register int *__ctidptr __asm__("r9") = child_tidptr;
1712
1713  __asm__ __volatile__(
1714      /* fn and arg are saved across the syscall */
1715      "mr 28, %5\n\t"
1716      "mr 27, %8\n\t"
1717
1718      /* syscall
1719        r0 == __NR_clone
1720        r3 == flags
1721        r4 == child_stack
1722        r5 == parent_tidptr
1723        r6 == newtls
1724        r7 == child_tidptr */
1725      "mr 3, %7\n\t"
1726      "mr 5, %9\n\t"
1727      "mr 6, %10\n\t"
1728      "mr 7, %11\n\t"
1729      "li 0, %3\n\t"
1730      "sc\n\t"
1731
1732      /* Test if syscall was successful */
1733      "cmpdi  cr1, 3, 0\n\t"
1734      "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t"
1735      "bne-   cr1, 1f\n\t"
1736
1737      /* Set up stack frame */
1738      "li    29, 0\n\t"
1739      "stdu  29, -8(1)\n\t"
1740      "stdu  1, -%12(1)\n\t"
1741      /* Do the function call */
1742      "std   2, %13(1)\n\t"
1743#      if SANITIZER_PPC64V1
1744      "ld    0, 0(28)\n\t"
1745      "ld    2, 8(28)\n\t"
1746      "mtctr 0\n\t"
1747#      elif SANITIZER_PPC64V2
1748      "mr    12, 28\n\t"
1749      "mtctr 12\n\t"
1750#      else
1751#        error "Unsupported PPC64 ABI"
1752#      endif
1753      "mr    3, 27\n\t"
1754      "bctrl\n\t"
1755      "ld    2, %13(1)\n\t"
1756
1757      /* Call _exit(r3) */
1758      "li 0, %4\n\t"
1759      "sc\n\t"
1760
1761      /* Return to parent */
1762      "1:\n\t"
1763      "mr %0, 3\n\t"
1764      : "=r"(res)
1765      : "0"(-1), "i"(EINVAL), "i"(__NR_clone), "i"(__NR_exit), "r"(__fn),
1766        "r"(__cstack), "r"(__flags), "r"(__arg), "r"(__ptidptr), "r"(__newtls),
1767        "r"(__ctidptr), "i"(FRAME_SIZE), "i"(FRAME_TOC_SAVE_OFFSET)
1768      : "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29");
1769  return res;
1770}
1771#    elif defined(__i386__)
1772uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1773                    int *parent_tidptr, void *newtls, int *child_tidptr) {
1774  int res;
1775  if (!fn || !child_stack)
1776    return -EINVAL;
1777  CHECK_EQ(0, (uptr)child_stack % 16);
1778  child_stack = (char *)child_stack - 7 * sizeof(unsigned int);
1779  ((unsigned int *)child_stack)[0] = (uptr)flags;
1780  ((unsigned int *)child_stack)[1] = (uptr)0;
1781  ((unsigned int *)child_stack)[2] = (uptr)fn;
1782  ((unsigned int *)child_stack)[3] = (uptr)arg;
1783  __asm__ __volatile__(
1784      /* %eax = syscall(%eax = SYSCALL(clone),
1785       *                %ebx = flags,
1786       *                %ecx = child_stack,
1787       *                %edx = parent_tidptr,
1788       *                %esi  = new_tls,
1789       *                %edi = child_tidptr)
1790       */
1791
1792      /* Obtain flags */
1793      "movl    (%%ecx), %%ebx\n"
1794      /* Do the system call */
1795      "pushl   %%ebx\n"
1796      "pushl   %%esi\n"
1797      "pushl   %%edi\n"
1798      /* Remember the flag value.  */
1799      "movl    %%ebx, (%%ecx)\n"
1800      "int     $0x80\n"
1801      "popl    %%edi\n"
1802      "popl    %%esi\n"
1803      "popl    %%ebx\n"
1804
1805      /* if (%eax != 0)
1806       *   return;
1807       */
1808
1809      "test    %%eax,%%eax\n"
1810      "jnz    1f\n"
1811
1812      /* terminate the stack frame */
1813      "xorl   %%ebp,%%ebp\n"
1814      /* Call FN. */
1815      "call    *%%ebx\n"
1816#      ifdef PIC
1817      "call    here\n"
1818      "here:\n"
1819      "popl    %%ebx\n"
1820      "addl    $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n"
1821#      endif
1822      /* Call exit */
1823      "movl    %%eax, %%ebx\n"
1824      "movl    %2, %%eax\n"
1825      "int     $0x80\n"
1826      "1:\n"
1827      : "=a"(res)
1828      : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)), "c"(child_stack),
1829        "d"(parent_tidptr), "S"(newtls), "D"(child_tidptr)
1830      : "memory");
1831  return res;
1832}
1833#    elif defined(__arm__)
1834uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1835                    int *parent_tidptr, void *newtls, int *child_tidptr) {
1836  unsigned int res;
1837  if (!fn || !child_stack)
1838    return -EINVAL;
1839  child_stack = (char *)child_stack - 2 * sizeof(unsigned int);
1840  ((unsigned int *)child_stack)[0] = (uptr)fn;
1841  ((unsigned int *)child_stack)[1] = (uptr)arg;
1842  register int r0 __asm__("r0") = flags;
1843  register void *r1 __asm__("r1") = child_stack;
1844  register int *r2 __asm__("r2") = parent_tidptr;
1845  register void *r3 __asm__("r3") = newtls;
1846  register int *r4 __asm__("r4") = child_tidptr;
1847  register int r7 __asm__("r7") = __NR_clone;
1848
1849#      if __ARM_ARCH > 4 || defined(__ARM_ARCH_4T__)
1850#        define ARCH_HAS_BX
1851#      endif
1852#      if __ARM_ARCH > 4
1853#        define ARCH_HAS_BLX
1854#      endif
1855
1856#      ifdef ARCH_HAS_BX
1857#        ifdef ARCH_HAS_BLX
1858#          define BLX(R) "blx " #R "\n"
1859#        else
1860#          define BLX(R) "mov lr, pc; bx " #R "\n"
1861#        endif
1862#      else
1863#        define BLX(R) "mov lr, pc; mov pc," #R "\n"
1864#      endif
1865
1866  __asm__ __volatile__(
1867      /* %r0 = syscall(%r7 = SYSCALL(clone),
1868       *               %r0 = flags,
1869       *               %r1 = child_stack,
1870       *               %r2 = parent_tidptr,
1871       *               %r3  = new_tls,
1872       *               %r4 = child_tidptr)
1873       */
1874
1875      /* Do the system call */
1876      "swi 0x0\n"
1877
1878      /* if (%r0 != 0)
1879       *   return %r0;
1880       */
1881      "cmp r0, #0\n"
1882      "bne 1f\n"
1883
1884      /* In the child, now. Call "fn(arg)". */
1885      "ldr r0, [sp, #4]\n"
1886      "ldr ip, [sp], #8\n" BLX(ip)
1887      /* Call _exit(%r0). */
1888      "mov r7, %7\n"
1889      "swi 0x0\n"
1890      "1:\n"
1891      "mov %0, r0\n"
1892      : "=r"(res)
1893      : "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7), "i"(__NR_exit)
1894      : "memory");
1895  return res;
1896}
1897#    endif
1898#  endif  // SANITIZER_LINUX
1899
1900#  if SANITIZER_LINUX
1901int internal_uname(struct utsname *buf) {
1902  return internal_syscall(SYSCALL(uname), buf);
1903}
1904#  endif
1905
1906static HandleSignalMode GetHandleSignalModeImpl(int signum) {
1907  switch (signum) {
1908    case SIGABRT:
1909      return common_flags()->handle_abort;
1910    case SIGILL:
1911      return common_flags()->handle_sigill;
1912    case SIGTRAP:
1913      return common_flags()->handle_sigtrap;
1914    case SIGFPE:
1915      return common_flags()->handle_sigfpe;
1916    case SIGSEGV:
1917      return common_flags()->handle_segv;
1918    case SIGBUS:
1919      return common_flags()->handle_sigbus;
1920  }
1921  return kHandleSignalNo;
1922}
1923
1924HandleSignalMode GetHandleSignalMode(int signum) {
1925  HandleSignalMode result = GetHandleSignalModeImpl(signum);
1926  if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler)
1927    return kHandleSignalExclusive;
1928  return result;
1929}
1930
1931#  if !SANITIZER_GO
1932void *internal_start_thread(void *(*func)(void *arg), void *arg) {
1933  if (&internal_pthread_create == 0)
1934    return nullptr;
1935  // Start the thread with signals blocked, otherwise it can steal user signals.
1936  ScopedBlockSignals block(nullptr);
1937  void *th;
1938  internal_pthread_create(&th, nullptr, func, arg);
1939  return th;
1940}
1941
1942void internal_join_thread(void *th) {
1943  if (&internal_pthread_join)
1944    internal_pthread_join(th, nullptr);
1945}
1946#  else
1947void *internal_start_thread(void *(*func)(void *), void *arg) { return 0; }
1948
1949void internal_join_thread(void *th) {}
1950#  endif
1951
1952#  if SANITIZER_LINUX && defined(__aarch64__)
1953// Android headers in the older NDK releases miss this definition.
1954struct __sanitizer_esr_context {
1955  struct _aarch64_ctx head;
1956  uint64_t esr;
1957};
1958
1959static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
1960  static const u32 kEsrMagic = 0x45535201;
1961  u8 *aux = reinterpret_cast<u8 *>(ucontext->uc_mcontext.__reserved);
1962  while (true) {
1963    _aarch64_ctx *ctx = (_aarch64_ctx *)aux;
1964    if (ctx->size == 0)
1965      break;
1966    if (ctx->magic == kEsrMagic) {
1967      *esr = ((__sanitizer_esr_context *)ctx)->esr;
1968      return true;
1969    }
1970    aux += ctx->size;
1971  }
1972  return false;
1973}
1974#  elif SANITIZER_FREEBSD && defined(__aarch64__)
1975// FreeBSD doesn't provide ESR in the ucontext.
1976static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) { return false; }
1977#  endif
1978
1979using Context = ucontext_t;
1980
1981SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
1982  Context *ucontext = (Context *)context;
1983#  if defined(__x86_64__) || defined(__i386__)
1984#    if !SANITIZER_HAIKU
1985  static const uptr PF_WRITE = 1U << 1;
1986#    endif
1987#    if SANITIZER_FREEBSD
1988  uptr err = ucontext->uc_mcontext.mc_err;
1989#    elif SANITIZER_NETBSD
1990  uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR];
1991#    elif SANITIZER_HAIKU
1992  uptr err = ucontext->uc_mcontext.r13;
1993#    elif SANITIZER_SOLARIS && defined(__i386__)
1994  const int Err = 13;
1995  uptr err = ucontext->uc_mcontext.gregs[Err];
1996#    else
1997  uptr err = ucontext->uc_mcontext.gregs[REG_ERR];
1998#    endif  // SANITIZER_FREEBSD
1999  return err & PF_WRITE ? Write : Read;
2000#  elif defined(__mips__)
2001  uint32_t *exception_source;
2002  uint32_t faulty_instruction;
2003  uint32_t op_code;
2004
2005  exception_source = (uint32_t *)ucontext->uc_mcontext.pc;
2006  faulty_instruction = (uint32_t)(*exception_source);
2007
2008  op_code = (faulty_instruction >> 26) & 0x3f;
2009
2010  // FIXME: Add support for FPU, microMIPS, DSP, MSA memory instructions.
2011  switch (op_code) {
2012    case 0x28:  // sb
2013    case 0x29:  // sh
2014    case 0x2b:  // sw
2015    case 0x3f:  // sd
2016#    if __mips_isa_rev < 6
2017    case 0x2c:  // sdl
2018    case 0x2d:  // sdr
2019    case 0x2a:  // swl
2020    case 0x2e:  // swr
2021#    endif
2022      return SignalContext::Write;
2023
2024    case 0x20:  // lb
2025    case 0x24:  // lbu
2026    case 0x21:  // lh
2027    case 0x25:  // lhu
2028    case 0x23:  // lw
2029    case 0x27:  // lwu
2030    case 0x37:  // ld
2031#    if __mips_isa_rev < 6
2032    case 0x1a:  // ldl
2033    case 0x1b:  // ldr
2034    case 0x22:  // lwl
2035    case 0x26:  // lwr
2036#    endif
2037      return SignalContext::Read;
2038#    if __mips_isa_rev == 6
2039    case 0x3b:  // pcrel
2040      op_code = (faulty_instruction >> 19) & 0x3;
2041      switch (op_code) {
2042        case 0x1:  // lwpc
2043        case 0x2:  // lwupc
2044          return SignalContext::Read;
2045      }
2046#    endif
2047  }
2048  return SignalContext::Unknown;
2049#  elif defined(__arm__)
2050  static const uptr FSR_WRITE = 1U << 11;
2051  uptr fsr = ucontext->uc_mcontext.error_code;
2052  return fsr & FSR_WRITE ? Write : Read;
2053#  elif defined(__aarch64__)
2054  static const u64 ESR_ELx_WNR = 1U << 6;
2055  u64 esr;
2056  if (!Aarch64GetESR(ucontext, &esr))
2057    return Unknown;
2058  return esr & ESR_ELx_WNR ? Write : Read;
2059#  elif defined(__loongarch__)
2060  // In the musl environment, the Linux kernel uapi sigcontext.h is not
2061  // included in signal.h. To avoid missing the SC_ADDRERR_{RD,WR} macros,
2062  // copy them here. The LoongArch Linux kernel uapi is already stable,
2063  // so there's no need to worry about the value changing.
2064#    ifndef SC_ADDRERR_RD
2065  // Address error was due to memory load
2066#      define SC_ADDRERR_RD (1 << 30)
2067#    endif
2068#    ifndef SC_ADDRERR_WR
2069  // Address error was due to memory store
2070#      define SC_ADDRERR_WR (1 << 31)
2071#    endif
2072  u32 flags = ucontext->uc_mcontext.__flags;
2073  if (flags & SC_ADDRERR_RD)
2074    return SignalContext::Read;
2075  if (flags & SC_ADDRERR_WR)
2076    return SignalContext::Write;
2077  return SignalContext::Unknown;
2078#  elif defined(__sparc__)
2079  // Decode the instruction to determine the access type.
2080  // From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype).
2081#    if SANITIZER_SOLARIS
2082  uptr pc = ucontext->uc_mcontext.gregs[REG_PC];
2083#    else
2084  // Historical BSDism here.
2085  struct sigcontext *scontext = (struct sigcontext *)context;
2086#      if defined(__arch64__)
2087  uptr pc = scontext->sigc_regs.tpc;
2088#      else
2089  uptr pc = scontext->si_regs.pc;
2090#      endif
2091#    endif
2092  u32 instr = *(u32 *)pc;
2093  return (instr >> 21) & 1 ? Write : Read;
2094#  elif defined(__riscv)
2095#    if SANITIZER_FREEBSD
2096  unsigned long pc = ucontext->uc_mcontext.mc_gpregs.gp_sepc;
2097#    else
2098  unsigned long pc = ucontext->uc_mcontext.__gregs[REG_PC];
2099#    endif
2100  unsigned faulty_instruction = *(uint16_t *)pc;
2101
2102#    if defined(__riscv_compressed)
2103  if ((faulty_instruction & 0x3) != 0x3) {  // it's a compressed instruction
2104    // set op_bits to the instruction bits [1, 0, 15, 14, 13]
2105    unsigned op_bits =
2106        ((faulty_instruction & 0x3) << 3) | (faulty_instruction >> 13);
2107    unsigned rd = faulty_instruction & 0xF80;  // bits 7-11, inclusive
2108    switch (op_bits) {
2109      case 0b10'010:  // c.lwsp (rd != x0)
2110#      if __riscv_xlen == 64
2111      case 0b10'011:  // c.ldsp (rd != x0)
2112#      endif
2113        return rd ? SignalContext::Read : SignalContext::Unknown;
2114      case 0b00'010:  // c.lw
2115#      if __riscv_flen >= 32 && __riscv_xlen == 32
2116      case 0b10'011:  // c.flwsp
2117#      endif
2118#      if __riscv_flen >= 32 || __riscv_xlen == 64
2119      case 0b00'011:  // c.flw / c.ld
2120#      endif
2121#      if __riscv_flen == 64
2122      case 0b00'001:  // c.fld
2123      case 0b10'001:  // c.fldsp
2124#      endif
2125        return SignalContext::Read;
2126      case 0b00'110:  // c.sw
2127      case 0b10'110:  // c.swsp
2128#      if __riscv_flen >= 32 || __riscv_xlen == 64
2129      case 0b00'111:  // c.fsw / c.sd
2130      case 0b10'111:  // c.fswsp / c.sdsp
2131#      endif
2132#      if __riscv_flen == 64
2133      case 0b00'101:  // c.fsd
2134      case 0b10'101:  // c.fsdsp
2135#      endif
2136        return SignalContext::Write;
2137      default:
2138        return SignalContext::Unknown;
2139    }
2140  }
2141#    endif
2142
2143  unsigned opcode = faulty_instruction & 0x7f;         // lower 7 bits
2144  unsigned funct3 = (faulty_instruction >> 12) & 0x7;  // bits 12-14, inclusive
2145  switch (opcode) {
2146    case 0b0000011:  // loads
2147      switch (funct3) {
2148        case 0b000:  // lb
2149        case 0b001:  // lh
2150        case 0b010:  // lw
2151#    if __riscv_xlen == 64
2152        case 0b011:  // ld
2153#    endif
2154        case 0b100:  // lbu
2155        case 0b101:  // lhu
2156          return SignalContext::Read;
2157        default:
2158          return SignalContext::Unknown;
2159      }
2160    case 0b0100011:  // stores
2161      switch (funct3) {
2162        case 0b000:  // sb
2163        case 0b001:  // sh
2164        case 0b010:  // sw
2165#    if __riscv_xlen == 64
2166        case 0b011:  // sd
2167#    endif
2168          return SignalContext::Write;
2169        default:
2170          return SignalContext::Unknown;
2171      }
2172#    if __riscv_flen >= 32
2173    case 0b0000111:  // floating-point loads
2174      switch (funct3) {
2175        case 0b010:  // flw
2176#      if __riscv_flen == 64
2177        case 0b011:  // fld
2178#      endif
2179          return SignalContext::Read;
2180        default:
2181          return SignalContext::Unknown;
2182      }
2183    case 0b0100111:  // floating-point stores
2184      switch (funct3) {
2185        case 0b010:  // fsw
2186#      if __riscv_flen == 64
2187        case 0b011:  // fsd
2188#      endif
2189          return SignalContext::Write;
2190        default:
2191          return SignalContext::Unknown;
2192      }
2193#    endif
2194    default:
2195      return SignalContext::Unknown;
2196  }
2197#  else
2198  (void)ucontext;
2199  return Unknown;  // FIXME: Implement.
2200#  endif
2201}
2202
2203bool SignalContext::IsTrueFaultingAddress() const {
2204  auto si = static_cast<const siginfo_t *>(siginfo);
2205  // SIGSEGV signals without a true fault address have si_code set to 128.
2206  return si->si_signo == SIGSEGV && si->si_code != 128;
2207}
2208
2209UNUSED
2210static const char *RegNumToRegName(int reg) {
2211  switch (reg) {
2212#  if SANITIZER_LINUX && SANITIZER_GLIBC || SANITIZER_NETBSD
2213#    if defined(__x86_64__)
2214#      if SANITIZER_NETBSD
2215#        define REG_RAX _REG_RAX
2216#        define REG_RBX _REG_RBX
2217#        define REG_RCX _REG_RCX
2218#        define REG_RDX _REG_RDX
2219#        define REG_RDI _REG_RDI
2220#        define REG_RSI _REG_RSI
2221#        define REG_RBP _REG_RBP
2222#        define REG_RSP _REG_RSP
2223#        define REG_R8 _REG_R8
2224#        define REG_R9 _REG_R9
2225#        define REG_R10 _REG_R10
2226#        define REG_R11 _REG_R11
2227#        define REG_R12 _REG_R12
2228#        define REG_R13 _REG_R13
2229#        define REG_R14 _REG_R14
2230#        define REG_R15 _REG_R15
2231#      endif
2232    case REG_RAX:
2233      return "rax";
2234    case REG_RBX:
2235      return "rbx";
2236    case REG_RCX:
2237      return "rcx";
2238    case REG_RDX:
2239      return "rdx";
2240    case REG_RDI:
2241      return "rdi";
2242    case REG_RSI:
2243      return "rsi";
2244    case REG_RBP:
2245      return "rbp";
2246    case REG_RSP:
2247      return "rsp";
2248    case REG_R8:
2249      return "r8";
2250    case REG_R9:
2251      return "r9";
2252    case REG_R10:
2253      return "r10";
2254    case REG_R11:
2255      return "r11";
2256    case REG_R12:
2257      return "r12";
2258    case REG_R13:
2259      return "r13";
2260    case REG_R14:
2261      return "r14";
2262    case REG_R15:
2263      return "r15";
2264#    elif defined(__i386__)
2265#      if SANITIZER_NETBSD
2266#        define REG_EAX _REG_EAX
2267#        define REG_EBX _REG_EBX
2268#        define REG_ECX _REG_ECX
2269#        define REG_EDX _REG_EDX
2270#        define REG_EDI _REG_EDI
2271#        define REG_ESI _REG_ESI
2272#        define REG_EBP _REG_EBP
2273#        define REG_ESP _REG_ESP
2274#      endif
2275    case REG_EAX:
2276      return "eax";
2277    case REG_EBX:
2278      return "ebx";
2279    case REG_ECX:
2280      return "ecx";
2281    case REG_EDX:
2282      return "edx";
2283    case REG_EDI:
2284      return "edi";
2285    case REG_ESI:
2286      return "esi";
2287    case REG_EBP:
2288      return "ebp";
2289    case REG_ESP:
2290      return "esp";
2291#    elif defined(__arm__)
2292#      ifdef MAKE_CASE
2293#        undef MAKE_CASE
2294#      endif
2295#      define REG_STR(reg) #reg
2296#      define MAKE_CASE(N) \
2297        case REG_R##N:     \
2298          return REG_STR(r##N)
2299    MAKE_CASE(0);
2300    MAKE_CASE(1);
2301    MAKE_CASE(2);
2302    MAKE_CASE(3);
2303    MAKE_CASE(4);
2304    MAKE_CASE(5);
2305    MAKE_CASE(6);
2306    MAKE_CASE(7);
2307    MAKE_CASE(8);
2308    MAKE_CASE(9);
2309    MAKE_CASE(10);
2310    MAKE_CASE(11);
2311    MAKE_CASE(12);
2312    case REG_R13:
2313      return "sp";
2314    case REG_R14:
2315      return "lr";
2316    case REG_R15:
2317      return "pc";
2318#    elif defined(__aarch64__)
2319#      define REG_STR(reg) #reg
2320#      define MAKE_CASE(N) \
2321        case N:            \
2322          return REG_STR(x##N)
2323    MAKE_CASE(0);
2324    MAKE_CASE(1);
2325    MAKE_CASE(2);
2326    MAKE_CASE(3);
2327    MAKE_CASE(4);
2328    MAKE_CASE(5);
2329    MAKE_CASE(6);
2330    MAKE_CASE(7);
2331    MAKE_CASE(8);
2332    MAKE_CASE(9);
2333    MAKE_CASE(10);
2334    MAKE_CASE(11);
2335    MAKE_CASE(12);
2336    MAKE_CASE(13);
2337    MAKE_CASE(14);
2338    MAKE_CASE(15);
2339    MAKE_CASE(16);
2340    MAKE_CASE(17);
2341    MAKE_CASE(18);
2342    MAKE_CASE(19);
2343    MAKE_CASE(20);
2344    MAKE_CASE(21);
2345    MAKE_CASE(22);
2346    MAKE_CASE(23);
2347    MAKE_CASE(24);
2348    MAKE_CASE(25);
2349    MAKE_CASE(26);
2350    MAKE_CASE(27);
2351    MAKE_CASE(28);
2352    case 29:
2353      return "fp";
2354    case 30:
2355      return "lr";
2356    case 31:
2357      return "sp";
2358#    endif
2359#  endif  // SANITIZER_LINUX && SANITIZER_GLIBC
2360    default:
2361      return NULL;
2362  }
2363  return NULL;
2364}
2365
2366#  if ((SANITIZER_LINUX && SANITIZER_GLIBC) || SANITIZER_NETBSD) && \
2367      (defined(__arm__) || defined(__aarch64__))
2368static uptr GetArmRegister(ucontext_t *ctx, int RegNum) {
2369  switch (RegNum) {
2370#    if defined(__arm__) && !SANITIZER_NETBSD
2371#      ifdef MAKE_CASE
2372#        undef MAKE_CASE
2373#      endif
2374#      define MAKE_CASE(N) \
2375        case REG_R##N:     \
2376          return ctx->uc_mcontext.arm_r##N
2377    MAKE_CASE(0);
2378    MAKE_CASE(1);
2379    MAKE_CASE(2);
2380    MAKE_CASE(3);
2381    MAKE_CASE(4);
2382    MAKE_CASE(5);
2383    MAKE_CASE(6);
2384    MAKE_CASE(7);
2385    MAKE_CASE(8);
2386    MAKE_CASE(9);
2387    MAKE_CASE(10);
2388    case REG_R11:
2389      return ctx->uc_mcontext.arm_fp;
2390    case REG_R12:
2391      return ctx->uc_mcontext.arm_ip;
2392    case REG_R13:
2393      return ctx->uc_mcontext.arm_sp;
2394    case REG_R14:
2395      return ctx->uc_mcontext.arm_lr;
2396    case REG_R15:
2397      return ctx->uc_mcontext.arm_pc;
2398#    elif defined(__aarch64__)
2399#      if SANITIZER_LINUX
2400    case 0 ... 30:
2401      return ctx->uc_mcontext.regs[RegNum];
2402    case 31:
2403      return ctx->uc_mcontext.sp;
2404#      elif SANITIZER_NETBSD
2405    case 0 ... 31:
2406      return ctx->uc_mcontext.__gregs[RegNum];
2407#      endif
2408#    endif
2409    default:
2410      return 0;
2411  }
2412  return 0;
2413}
2414#  endif  // SANITIZER_LINUX && SANITIZER_GLIBC && (defined(__arm__) ||
2415          // defined(__aarch64__))
2416
2417UNUSED
2418static void DumpSingleReg(ucontext_t *ctx, int RegNum) {
2419  const char *RegName = RegNumToRegName(RegNum);
2420#  if SANITIZER_LINUX && SANITIZER_GLIBC || SANITIZER_NETBSD
2421#    if defined(__x86_64__)
2422  Printf("%s%s = 0x%016llx  ", internal_strlen(RegName) == 2 ? " " : "",
2423         RegName,
2424#      if SANITIZER_LINUX
2425         ctx->uc_mcontext.gregs[RegNum]
2426#      elif SANITIZER_NETBSD
2427         ctx->uc_mcontext.__gregs[RegNum]
2428#      endif
2429  );
2430#    elif defined(__i386__)
2431  Printf("%s = 0x%08x  ", RegName,
2432#      if SANITIZER_LINUX
2433         ctx->uc_mcontext.gregs[RegNum]
2434#      elif SANITIZER_NETBSD
2435         ctx->uc_mcontext.__gregs[RegNum]
2436#      endif
2437  );
2438#    elif defined(__arm__)
2439  Printf("%s%s = 0x%08zx  ", internal_strlen(RegName) == 2 ? " " : "", RegName,
2440         GetArmRegister(ctx, RegNum));
2441#    elif defined(__aarch64__)
2442  Printf("%s%s = 0x%016zx  ", internal_strlen(RegName) == 2 ? " " : "", RegName,
2443         GetArmRegister(ctx, RegNum));
2444#    else
2445  (void)RegName;
2446#    endif
2447#  else
2448  (void)RegName;
2449#  endif
2450}
2451
2452void SignalContext::DumpAllRegisters(void *context) {
2453  ucontext_t *ucontext = (ucontext_t *)context;
2454#  if SANITIZER_LINUX && SANITIZER_GLIBC || SANITIZER_NETBSD
2455#    if defined(__x86_64__)
2456  Report("Register values:\n");
2457  DumpSingleReg(ucontext, REG_RAX);
2458  DumpSingleReg(ucontext, REG_RBX);
2459  DumpSingleReg(ucontext, REG_RCX);
2460  DumpSingleReg(ucontext, REG_RDX);
2461  Printf("\n");
2462  DumpSingleReg(ucontext, REG_RDI);
2463  DumpSingleReg(ucontext, REG_RSI);
2464  DumpSingleReg(ucontext, REG_RBP);
2465  DumpSingleReg(ucontext, REG_RSP);
2466  Printf("\n");
2467  DumpSingleReg(ucontext, REG_R8);
2468  DumpSingleReg(ucontext, REG_R9);
2469  DumpSingleReg(ucontext, REG_R10);
2470  DumpSingleReg(ucontext, REG_R11);
2471  Printf("\n");
2472  DumpSingleReg(ucontext, REG_R12);
2473  DumpSingleReg(ucontext, REG_R13);
2474  DumpSingleReg(ucontext, REG_R14);
2475  DumpSingleReg(ucontext, REG_R15);
2476  Printf("\n");
2477#    elif defined(__i386__)
2478  // Duplication of this report print is caused by partial support
2479  // of register values dumping. In case of unsupported yet architecture let's
2480  // avoid printing 'Register values:' without actual values in the following
2481  // output.
2482  Report("Register values:\n");
2483  DumpSingleReg(ucontext, REG_EAX);
2484  DumpSingleReg(ucontext, REG_EBX);
2485  DumpSingleReg(ucontext, REG_ECX);
2486  DumpSingleReg(ucontext, REG_EDX);
2487  Printf("\n");
2488  DumpSingleReg(ucontext, REG_EDI);
2489  DumpSingleReg(ucontext, REG_ESI);
2490  DumpSingleReg(ucontext, REG_EBP);
2491  DumpSingleReg(ucontext, REG_ESP);
2492  Printf("\n");
2493#    elif defined(__arm__) && !SANITIZER_NETBSD
2494  Report("Register values:\n");
2495  DumpSingleReg(ucontext, REG_R0);
2496  DumpSingleReg(ucontext, REG_R1);
2497  DumpSingleReg(ucontext, REG_R2);
2498  DumpSingleReg(ucontext, REG_R3);
2499  Printf("\n");
2500  DumpSingleReg(ucontext, REG_R4);
2501  DumpSingleReg(ucontext, REG_R5);
2502  DumpSingleReg(ucontext, REG_R6);
2503  DumpSingleReg(ucontext, REG_R7);
2504  Printf("\n");
2505  DumpSingleReg(ucontext, REG_R8);
2506  DumpSingleReg(ucontext, REG_R9);
2507  DumpSingleReg(ucontext, REG_R10);
2508  DumpSingleReg(ucontext, REG_R11);
2509  Printf("\n");
2510  DumpSingleReg(ucontext, REG_R12);
2511  DumpSingleReg(ucontext, REG_R13);
2512  DumpSingleReg(ucontext, REG_R14);
2513  DumpSingleReg(ucontext, REG_R15);
2514  Printf("\n");
2515#    elif defined(__aarch64__)
2516  Report("Register values:\n");
2517  for (int i = 0; i <= 31; ++i) {
2518    DumpSingleReg(ucontext, i);
2519    if (i % 4 == 3)
2520      Printf("\n");
2521  }
2522#    else
2523  (void)ucontext;
2524#    endif
2525#  elif SANITIZER_FREEBSD
2526#    if defined(__x86_64__)
2527  Report("Register values:\n");
2528  Printf("rax = 0x%016lx  ", ucontext->uc_mcontext.mc_rax);
2529  Printf("rbx = 0x%016lx  ", ucontext->uc_mcontext.mc_rbx);
2530  Printf("rcx = 0x%016lx  ", ucontext->uc_mcontext.mc_rcx);
2531  Printf("rdx = 0x%016lx  ", ucontext->uc_mcontext.mc_rdx);
2532  Printf("\n");
2533  Printf("rdi = 0x%016lx  ", ucontext->uc_mcontext.mc_rdi);
2534  Printf("rsi = 0x%016lx  ", ucontext->uc_mcontext.mc_rsi);
2535  Printf("rbp = 0x%016lx  ", ucontext->uc_mcontext.mc_rbp);
2536  Printf("rsp = 0x%016lx  ", ucontext->uc_mcontext.mc_rsp);
2537  Printf("\n");
2538  Printf(" r8 = 0x%016lx  ", ucontext->uc_mcontext.mc_r8);
2539  Printf(" r9 = 0x%016lx  ", ucontext->uc_mcontext.mc_r9);
2540  Printf("r10 = 0x%016lx  ", ucontext->uc_mcontext.mc_r10);
2541  Printf("r11 = 0x%016lx  ", ucontext->uc_mcontext.mc_r11);
2542  Printf("\n");
2543  Printf("r12 = 0x%016lx  ", ucontext->uc_mcontext.mc_r12);
2544  Printf("r13 = 0x%016lx  ", ucontext->uc_mcontext.mc_r13);
2545  Printf("r14 = 0x%016lx  ", ucontext->uc_mcontext.mc_r14);
2546  Printf("r15 = 0x%016lx  ", ucontext->uc_mcontext.mc_r15);
2547  Printf("\n");
2548#    elif defined(__i386__)
2549  Report("Register values:\n");
2550  Printf("eax = 0x%08x  ", ucontext->uc_mcontext.mc_eax);
2551  Printf("ebx = 0x%08x  ", ucontext->uc_mcontext.mc_ebx);
2552  Printf("ecx = 0x%08x  ", ucontext->uc_mcontext.mc_ecx);
2553  Printf("edx = 0x%08x  ", ucontext->uc_mcontext.mc_edx);
2554  Printf("\n");
2555  Printf("edi = 0x%08x  ", ucontext->uc_mcontext.mc_edi);
2556  Printf("esi = 0x%08x  ", ucontext->uc_mcontext.mc_esi);
2557  Printf("ebp = 0x%08x  ", ucontext->uc_mcontext.mc_ebp);
2558  Printf("esp = 0x%08x  ", ucontext->uc_mcontext.mc_esp);
2559  Printf("\n");
2560#    else
2561  (void)ucontext;
2562#    endif
2563#  else
2564  (void)ucontext;
2565#  endif
2566  // FIXME: Implement this for other OSes and architectures.
2567}
2568
2569static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
2570#  if SANITIZER_NETBSD
2571  // This covers all NetBSD architectures
2572  ucontext_t *ucontext = (ucontext_t *)context;
2573  *pc = _UC_MACHINE_PC(ucontext);
2574  *bp = _UC_MACHINE_FP(ucontext);
2575  *sp = _UC_MACHINE_SP(ucontext);
2576#  elif defined(__arm__)
2577  ucontext_t *ucontext = (ucontext_t *)context;
2578  *pc = ucontext->uc_mcontext.arm_pc;
2579  *bp = ucontext->uc_mcontext.arm_fp;
2580  *sp = ucontext->uc_mcontext.arm_sp;
2581#  elif defined(__aarch64__)
2582#    if SANITIZER_FREEBSD
2583  ucontext_t *ucontext = (ucontext_t *)context;
2584  *pc = ucontext->uc_mcontext.mc_gpregs.gp_elr;
2585  *bp = ucontext->uc_mcontext.mc_gpregs.gp_x[29];
2586  *sp = ucontext->uc_mcontext.mc_gpregs.gp_sp;
2587#    else
2588  ucontext_t *ucontext = (ucontext_t *)context;
2589  *pc = ucontext->uc_mcontext.pc;
2590  *bp = ucontext->uc_mcontext.regs[29];
2591  *sp = ucontext->uc_mcontext.sp;
2592#    endif
2593#  elif defined(__hppa__)
2594  ucontext_t *ucontext = (ucontext_t *)context;
2595  *pc = ucontext->uc_mcontext.sc_iaoq[0];
2596  /* GCC uses %r3 whenever a frame pointer is needed.  */
2597  *bp = ucontext->uc_mcontext.sc_gr[3];
2598  *sp = ucontext->uc_mcontext.sc_gr[30];
2599#  elif defined(__x86_64__)
2600#    if SANITIZER_FREEBSD
2601  ucontext_t *ucontext = (ucontext_t *)context;
2602  *pc = ucontext->uc_mcontext.mc_rip;
2603  *bp = ucontext->uc_mcontext.mc_rbp;
2604  *sp = ucontext->uc_mcontext.mc_rsp;
2605#    elif SANITIZER_HAIKU
2606  ucontext_t *ucontext = (ucontext_t *)context;
2607  *pc = ucontext->uc_mcontext.rip;
2608  *bp = ucontext->uc_mcontext.rbp;
2609  *sp = ucontext->uc_mcontext.rsp;
2610#    else
2611  ucontext_t *ucontext = (ucontext_t *)context;
2612  *pc = ucontext->uc_mcontext.gregs[REG_RIP];
2613  *bp = ucontext->uc_mcontext.gregs[REG_RBP];
2614  *sp = ucontext->uc_mcontext.gregs[REG_RSP];
2615#    endif
2616#  elif defined(__i386__)
2617#    if SANITIZER_FREEBSD
2618  ucontext_t *ucontext = (ucontext_t *)context;
2619  *pc = ucontext->uc_mcontext.mc_eip;
2620  *bp = ucontext->uc_mcontext.mc_ebp;
2621  *sp = ucontext->uc_mcontext.mc_esp;
2622#    else
2623  ucontext_t *ucontext = (ucontext_t *)context;
2624#      if SANITIZER_SOLARIS
2625  /* Use the numeric values: the symbolic ones are undefined by llvm
2626     include/llvm/Support/Solaris.h.  */
2627#        ifndef REG_EIP
2628#          define REG_EIP 14  // REG_PC
2629#        endif
2630#        ifndef REG_EBP
2631#          define REG_EBP 6  // REG_FP
2632#        endif
2633#        ifndef REG_UESP
2634#          define REG_UESP 17  // REG_SP
2635#        endif
2636#      endif
2637  *pc = ucontext->uc_mcontext.gregs[REG_EIP];
2638  *bp = ucontext->uc_mcontext.gregs[REG_EBP];
2639  *sp = ucontext->uc_mcontext.gregs[REG_UESP];
2640#    endif
2641#  elif defined(__powerpc__) || defined(__powerpc64__)
2642#    if SANITIZER_FREEBSD
2643  ucontext_t *ucontext = (ucontext_t *)context;
2644  *pc = ucontext->uc_mcontext.mc_srr0;
2645  *sp = ucontext->uc_mcontext.mc_frame[1];
2646  *bp = ucontext->uc_mcontext.mc_frame[31];
2647#    else
2648  ucontext_t *ucontext = (ucontext_t *)context;
2649  *pc = ucontext->uc_mcontext.regs->nip;
2650  *sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
2651  // The powerpc{,64}-linux ABIs do not specify r31 as the frame
2652  // pointer, but GCC always uses r31 when we need a frame pointer.
2653  *bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
2654#    endif
2655#  elif defined(__sparc__)
2656#    if defined(__arch64__) || defined(__sparcv9)
2657#      define STACK_BIAS 2047
2658#    else
2659#      define STACK_BIAS 0
2660#    endif
2661#    if SANITIZER_SOLARIS
2662  ucontext_t *ucontext = (ucontext_t *)context;
2663  *pc = ucontext->uc_mcontext.gregs[REG_PC];
2664  *sp = ucontext->uc_mcontext.gregs[REG_SP] + STACK_BIAS;
2665  // Avoid SEGV when dereferencing sp on stack overflow with non-faulting load.
2666  // This requires a SPARC V9 CPU.  Cannot use #ASI_PNF here: only supported
2667  // since clang-19.
2668#      if defined(__sparcv9)
2669  asm("ldxa [%[fp]] 0x82, %[bp]"
2670#      else
2671  asm("lduwa [%[fp]] 0x82, %[bp]"
2672#      endif
2673      : [bp] "=r"(*bp)
2674      : [fp] "r"(&((struct frame *)*sp)->fr_savfp));
2675  if (*bp)
2676    *bp += STACK_BIAS;
2677#    else
2678  // Historical BSDism here.
2679  struct sigcontext *scontext = (struct sigcontext *)context;
2680#      if defined(__arch64__)
2681  *pc = scontext->sigc_regs.tpc;
2682  *sp = scontext->sigc_regs.u_regs[14] + STACK_BIAS;
2683#      else
2684  *pc = scontext->si_regs.pc;
2685  *sp = scontext->si_regs.u_regs[14];
2686#      endif
2687  *bp = (uptr)((uhwptr *)*sp)[14] + STACK_BIAS;
2688#    endif
2689#  elif defined(__mips__)
2690  ucontext_t *ucontext = (ucontext_t *)context;
2691  *pc = ucontext->uc_mcontext.pc;
2692  *bp = ucontext->uc_mcontext.gregs[30];
2693  *sp = ucontext->uc_mcontext.gregs[29];
2694#  elif defined(__s390__)
2695  ucontext_t *ucontext = (ucontext_t *)context;
2696#    if defined(__s390x__)
2697  *pc = ucontext->uc_mcontext.psw.addr;
2698#    else
2699  *pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff;
2700#    endif
2701  *bp = ucontext->uc_mcontext.gregs[11];
2702  *sp = ucontext->uc_mcontext.gregs[15];
2703#  elif defined(__riscv)
2704  ucontext_t *ucontext = (ucontext_t *)context;
2705#    if SANITIZER_FREEBSD
2706  *pc = ucontext->uc_mcontext.mc_gpregs.gp_sepc;
2707  *bp = ucontext->uc_mcontext.mc_gpregs.gp_s[0];
2708  *sp = ucontext->uc_mcontext.mc_gpregs.gp_sp;
2709#    else
2710  *pc = ucontext->uc_mcontext.__gregs[REG_PC];
2711  *bp = ucontext->uc_mcontext.__gregs[REG_S0];
2712  *sp = ucontext->uc_mcontext.__gregs[REG_SP];
2713#    endif
2714#  elif defined(__hexagon__)
2715  ucontext_t *ucontext = (ucontext_t *)context;
2716  *pc = ucontext->uc_mcontext.pc;
2717  *bp = ucontext->uc_mcontext.r30;
2718  *sp = ucontext->uc_mcontext.r29;
2719#  elif defined(__loongarch__)
2720  ucontext_t *ucontext = (ucontext_t *)context;
2721  *pc = ucontext->uc_mcontext.__pc;
2722  *bp = ucontext->uc_mcontext.__gregs[22];
2723  *sp = ucontext->uc_mcontext.__gregs[3];
2724#  else
2725#    error "Unsupported arch"
2726#  endif
2727}
2728
2729void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); }
2730
2731void InitializePlatformEarly() { InitTlsSize(); }
2732
2733void CheckASLR() {
2734#  if SANITIZER_NETBSD
2735  int mib[3];
2736  int paxflags;
2737  uptr len = sizeof(paxflags);
2738
2739  mib[0] = CTL_PROC;
2740  mib[1] = internal_getpid();
2741  mib[2] = PROC_PID_PAXFLAGS;
2742
2743  if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
2744    Printf("sysctl failed\n");
2745    Die();
2746  }
2747
2748  if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_ASLR)) {
2749    Printf(
2750        "This sanitizer is not compatible with enabled ASLR.\n"
2751        "To disable ASLR, please run \"paxctl +a %s\" and try again.\n",
2752        GetArgv()[0]);
2753    Die();
2754  }
2755#  elif SANITIZER_FREEBSD
2756  int aslr_status;
2757  int r = internal_procctl(P_PID, 0, PROC_ASLR_STATUS, &aslr_status);
2758  if (UNLIKELY(r == -1)) {
2759    // We're making things less 'dramatic' here since
2760    // the cmd is not necessarily guaranteed to be here
2761    // just yet regarding FreeBSD release
2762    return;
2763  }
2764  if ((aslr_status & PROC_ASLR_ACTIVE) != 0) {
2765    VReport(1,
2766            "This sanitizer is not compatible with enabled ASLR "
2767            "and binaries compiled with PIE\n"
2768            "ASLR will be disabled and the program re-executed.\n");
2769    int aslr_ctl = PROC_ASLR_FORCE_DISABLE;
2770    CHECK_NE(internal_procctl(P_PID, 0, PROC_ASLR_CTL, &aslr_ctl), -1);
2771    ReExec();
2772  }
2773#  elif SANITIZER_PPC64V2
2774  // Disable ASLR for Linux PPC64LE.
2775  int old_personality = personality(0xffffffff);
2776  if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
2777    VReport(1,
2778            "WARNING: Program is being run with address space layout "
2779            "randomization (ASLR) enabled which prevents the thread and "
2780            "memory sanitizers from working on powerpc64le.\n"
2781            "ASLR will be disabled and the program re-executed.\n");
2782    CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
2783    ReExec();
2784  }
2785#  else
2786  // Do nothing
2787#  endif
2788}
2789
2790void CheckMPROTECT() {
2791#  if SANITIZER_NETBSD
2792  int mib[3];
2793  int paxflags;
2794  uptr len = sizeof(paxflags);
2795
2796  mib[0] = CTL_PROC;
2797  mib[1] = internal_getpid();
2798  mib[2] = PROC_PID_PAXFLAGS;
2799
2800  if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
2801    Printf("sysctl failed\n");
2802    Die();
2803  }
2804
2805  if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_MPROTECT)) {
2806    Printf("This sanitizer is not compatible with enabled MPROTECT\n");
2807    Die();
2808  }
2809#  else
2810  // Do nothing
2811#  endif
2812}
2813
2814void CheckNoDeepBind(const char *filename, int flag) {
2815#  ifdef RTLD_DEEPBIND
2816  if (flag & RTLD_DEEPBIND) {
2817    Report(
2818        "You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag"
2819        " which is incompatible with sanitizer runtime "
2820        "(see https://github.com/google/sanitizers/issues/611 for details"
2821        "). If you want to run %s library under sanitizers please remove "
2822        "RTLD_DEEPBIND from dlopen flags.\n",
2823        filename, filename);
2824    Die();
2825  }
2826#  endif
2827}
2828
2829uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
2830                              uptr *largest_gap_found,
2831                              uptr *max_occupied_addr) {
2832  UNREACHABLE("FindAvailableMemoryRange is not available");
2833  return 0;
2834}
2835
2836bool GetRandom(void *buffer, uptr length, bool blocking) {
2837  if (!buffer || !length || length > 256)
2838    return false;
2839#  if SANITIZER_USE_GETENTROPY
2840  uptr rnd = getentropy(buffer, length);
2841  int rverrno = 0;
2842  if (internal_iserror(rnd, &rverrno) && rverrno == EFAULT)
2843    return false;
2844  else if (rnd == 0)
2845    return true;
2846#  endif  // SANITIZER_USE_GETENTROPY
2847
2848#  if SANITIZER_USE_GETRANDOM
2849  static atomic_uint8_t skip_getrandom_syscall;
2850  if (!atomic_load_relaxed(&skip_getrandom_syscall)) {
2851    // Up to 256 bytes, getrandom will not be interrupted.
2852    uptr res = internal_syscall(SYSCALL(getrandom), buffer, length,
2853                                blocking ? 0 : GRND_NONBLOCK);
2854    int rverrno = 0;
2855    if (internal_iserror(res, &rverrno) && rverrno == ENOSYS)
2856      atomic_store_relaxed(&skip_getrandom_syscall, 1);
2857    else if (res == length)
2858      return true;
2859  }
2860#  endif  // SANITIZER_USE_GETRANDOM
2861  // Up to 256 bytes, a read off /dev/urandom will not be interrupted.
2862  // blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom.
2863  uptr fd = internal_open("/dev/urandom", O_RDONLY);
2864  if (internal_iserror(fd))
2865    return false;
2866  uptr res = internal_read(fd, buffer, length);
2867  if (internal_iserror(res))
2868    return false;
2869  internal_close(fd);
2870  return true;
2871}
2872
2873}  // namespace __sanitizer
2874
2875#endif