ydb-oss sync: add clang16-rt/ to additionalPathsToCopy

1 files changed, 2428 insertions, 0 deletions

diff --git a/contrib/libs/clang16-rt/lib/sanitizer_common/sanitizer_linux.cpp b/contrib/libs/clang16-rt/lib/sanitizer_common/sanitizer_linux.cpp
new file mode 100644
index 0000000000..19a5ee8926
--- /dev/null
+++ b/contrib/libs/clang16-rt/lib/sanitizer_common/sanitizer_linux.cpp
@@ -0,0 +1,2428 @@
+//===-- sanitizer_linux.cpp -----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between AddressSanitizer and ThreadSanitizer
+// run-time libraries and implements linux-specific functions from
+// sanitizer_libc.h.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
+    SANITIZER_SOLARIS
+
+#include "sanitizer_common.h"
+#include "sanitizer_flags.h"
+#include "sanitizer_getauxval.h"
+#include "sanitizer_internal_defs.h"
+#include "sanitizer_libc.h"
+#include "sanitizer_linux.h"
+#include "sanitizer_mutex.h"
+#include "sanitizer_placement_new.h"
+#include "sanitizer_procmaps.h"
+
+#if SANITIZER_LINUX && !SANITIZER_GO
+#include <asm/param.h>
+#endif
+
+// For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat'
+// format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To
+// access stat from asm/stat.h, without conflicting with definition in
+// sys/stat.h, we use this trick.
+#if SANITIZER_MIPS64
+#include <asm/unistd.h>
+#include <sys/types.h>
+#define stat kernel_stat
+#if SANITIZER_GO
+#undef st_atime
+#undef st_mtime
+#undef st_ctime
+#define st_atime st_atim
+#define st_mtime st_mtim
+#define st_ctime st_ctim
+#endif
+#include <asm/stat.h>
+#undef stat
+#endif
+
+#include <dlfcn.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <link.h>
+#include <pthread.h>
+#include <sched.h>
+#include <signal.h>
+#include <sys/mman.h>
+#include <sys/param.h>
+#if !SANITIZER_SOLARIS
+#include <sys/ptrace.h>
+#endif
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <ucontext.h>
+#include <unistd.h>
+
+#if SANITIZER_LINUX
+#include <sys/utsname.h>
+#endif
+
+#if SANITIZER_LINUX && !SANITIZER_ANDROID
+#include <sys/personality.h>
+#endif
+
+#if SANITIZER_LINUX && defined(__loongarch__)
+#  include <sys/sysmacros.h>
+#endif
+
+#if SANITIZER_FREEBSD
+#include <sys/exec.h>
+#error #include <sys/procctl.h>
+#include <sys/sysctl.h>
+#include <machine/atomic.h>
+extern "C" {
+// <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on
+// FreeBSD 9.2 and 10.0.
+#include <sys/umtx.h>
+}
+#include <sys/thr.h>
+#endif  // SANITIZER_FREEBSD
+
+#if SANITIZER_NETBSD
+#include <limits.h>  // For NAME_MAX
+#include <sys/sysctl.h>
+#include <sys/exec.h>
+extern struct ps_strings *__ps_strings;
+#endif  // SANITIZER_NETBSD
+
+#if SANITIZER_SOLARIS
+#include <stdlib.h>
+#include <thread.h>
+#define environ _environ
+#endif
+
+extern char **environ;
+
+#if SANITIZER_LINUX
+// <linux/time.h>
+struct kernel_timeval {
+  long tv_sec;
+  long tv_usec;
+};
+
+// <linux/futex.h> is broken on some linux distributions.
+const int FUTEX_WAIT = 0;
+const int FUTEX_WAKE = 1;
+const int FUTEX_PRIVATE_FLAG = 128;
+const int FUTEX_WAIT_PRIVATE = FUTEX_WAIT | FUTEX_PRIVATE_FLAG;
+const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG;
+#endif  // SANITIZER_LINUX
+
+// Are we using 32-bit or 64-bit Linux syscalls?
+// x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
+// but it still needs to use 64-bit syscalls.
+#if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \
+                        SANITIZER_WORDSIZE == 64 ||                      \
+                        (defined(__mips__) && _MIPS_SIM == _ABIN32))
+# define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
+#else
+# define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
+#endif
+
+// Note : FreeBSD had implemented both
+// Linux apis, available from
+// future 12.x version most likely
+#if SANITIZER_LINUX && defined(__NR_getrandom)
+# if !defined(GRND_NONBLOCK)
+#  define GRND_NONBLOCK 1
+# endif
+# define SANITIZER_USE_GETRANDOM 1
+#else
+# define SANITIZER_USE_GETRANDOM 0
+#endif  // SANITIZER_LINUX && defined(__NR_getrandom)
+
+#if SANITIZER_FREEBSD && __FreeBSD_version >= 1200000
+#  define SANITIZER_USE_GETENTROPY 1
+#else
+#  define SANITIZER_USE_GETENTROPY 0
+#endif
+
+namespace __sanitizer {
+
+void SetSigProcMask(__sanitizer_sigset_t *set, __sanitizer_sigset_t *old) {
+  CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, set, old));
+}
+
+ScopedBlockSignals::ScopedBlockSignals(__sanitizer_sigset_t *copy) {
+  __sanitizer_sigset_t set;
+  internal_sigfillset(&set);
+#  if SANITIZER_LINUX && !SANITIZER_ANDROID
+  // Glibc uses SIGSETXID signal during setuid call. If this signal is blocked
+  // on any thread, setuid call hangs.
+  // See test/sanitizer_common/TestCases/Linux/setuid.c.
+  internal_sigdelset(&set, 33);
+#  endif
+#  if SANITIZER_LINUX
+  // Seccomp-BPF-sandboxed processes rely on SIGSYS to handle trapped syscalls.
+  // If this signal is blocked, such calls cannot be handled and the process may
+  // hang.
+  internal_sigdelset(&set, 31);
+#  endif
+  SetSigProcMask(&set, &saved_);
+  if (copy)
+    internal_memcpy(copy, &saved_, sizeof(saved_));
+}
+
+ScopedBlockSignals::~ScopedBlockSignals() { SetSigProcMask(&saved_, nullptr); }
+
+#  if SANITIZER_LINUX && defined(__x86_64__)
+#    include "sanitizer_syscall_linux_x86_64.inc"
+#  elif SANITIZER_LINUX && SANITIZER_RISCV64
+#    include "sanitizer_syscall_linux_riscv64.inc"
+#  elif SANITIZER_LINUX && defined(__aarch64__)
+#    include "sanitizer_syscall_linux_aarch64.inc"
+#  elif SANITIZER_LINUX && defined(__arm__)
+#    include "sanitizer_syscall_linux_arm.inc"
+#  elif SANITIZER_LINUX && defined(__hexagon__)
+#    include "sanitizer_syscall_linux_hexagon.inc"
+#  elif SANITIZER_LINUX && SANITIZER_LOONGARCH64
+#    include "sanitizer_syscall_linux_loongarch64.inc"
+#  else
+#    include "sanitizer_syscall_generic.inc"
+#  endif
+
+// --------------- sanitizer_libc.h
+#if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
+#if !SANITIZER_S390
+uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
+                   u64 offset) {
+#if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
+  return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd,
+                          offset);
+#else
+  // mmap2 specifies file offset in 4096-byte units.
+  CHECK(IsAligned(offset, 4096));
+  return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd,
+                          offset / 4096);
+#endif
+}
+#endif // !SANITIZER_S390
+
+uptr internal_munmap(void *addr, uptr length) {
+  return internal_syscall(SYSCALL(munmap), (uptr)addr, length);
+}
+
+#if SANITIZER_LINUX
+uptr internal_mremap(void *old_address, uptr old_size, uptr new_size, int flags,
+                     void *new_address) {
+  return internal_syscall(SYSCALL(mremap), (uptr)old_address, old_size,
+                          new_size, flags, (uptr)new_address);
+}
+#endif
+
+int internal_mprotect(void *addr, uptr length, int prot) {
+  return internal_syscall(SYSCALL(mprotect), (uptr)addr, length, prot);
+}
+
+int internal_madvise(uptr addr, uptr length, int advice) {
+  return internal_syscall(SYSCALL(madvise), addr, length, advice);
+}
+
+uptr internal_close(fd_t fd) {
+  return internal_syscall(SYSCALL(close), fd);
+}
+
+uptr internal_open(const char *filename, int flags) {
+#    if SANITIZER_LINUX
+  return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags);
+#else
+  return internal_syscall(SYSCALL(open), (uptr)filename, flags);
+#endif
+}
+
+uptr internal_open(const char *filename, int flags, u32 mode) {
+#    if SANITIZER_LINUX
+  return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags,
+                          mode);
+#else
+  return internal_syscall(SYSCALL(open), (uptr)filename, flags, mode);
+#endif
+}
+
+uptr internal_read(fd_t fd, void *buf, uptr count) {
+  sptr res;
+  HANDLE_EINTR(res,
+               (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf, count));
+  return res;
+}
+
+uptr internal_write(fd_t fd, const void *buf, uptr count) {
+  sptr res;
+  HANDLE_EINTR(res,
+               (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf, count));
+  return res;
+}
+
+uptr internal_ftruncate(fd_t fd, uptr size) {
+  sptr res;
+  HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd,
+               (OFF_T)size));
+  return res;
+}
+
+#if (!SANITIZER_LINUX_USES_64BIT_SYSCALLS || SANITIZER_SPARC) && SANITIZER_LINUX
+static void stat64_to_stat(struct stat64 *in, struct stat *out) {
+  internal_memset(out, 0, sizeof(*out));
+  out->st_dev = in->st_dev;
+  out->st_ino = in->st_ino;
+  out->st_mode = in->st_mode;
+  out->st_nlink = in->st_nlink;
+  out->st_uid = in->st_uid;
+  out->st_gid = in->st_gid;
+  out->st_rdev = in->st_rdev;
+  out->st_size = in->st_size;
+  out->st_blksize = in->st_blksize;
+  out->st_blocks = in->st_blocks;
+  out->st_atime = in->st_atime;
+  out->st_mtime = in->st_mtime;
+  out->st_ctime = in->st_ctime;
+}
+#endif
+
+#if SANITIZER_LINUX && defined(__loongarch__)
+static void statx_to_stat(struct statx *in, struct stat *out) {
+  internal_memset(out, 0, sizeof(*out));
+  out->st_dev = makedev(in->stx_dev_major, in->stx_dev_minor);
+  out->st_ino = in->stx_ino;
+  out->st_mode = in->stx_mode;
+  out->st_nlink = in->stx_nlink;
+  out->st_uid = in->stx_uid;
+  out->st_gid = in->stx_gid;
+  out->st_rdev = makedev(in->stx_rdev_major, in->stx_rdev_minor);
+  out->st_size = in->stx_size;
+  out->st_blksize = in->stx_blksize;
+  out->st_blocks = in->stx_blocks;
+  out->st_atime = in->stx_atime.tv_sec;
+  out->st_atim.tv_nsec = in->stx_atime.tv_nsec;
+  out->st_mtime = in->stx_mtime.tv_sec;
+  out->st_mtim.tv_nsec = in->stx_mtime.tv_nsec;
+  out->st_ctime = in->stx_ctime.tv_sec;
+  out->st_ctim.tv_nsec = in->stx_ctime.tv_nsec;
+}
+#endif
+
+#if SANITIZER_MIPS64
+// Undefine compatibility macros from <sys/stat.h>
+// so that they would not clash with the kernel_stat
+// st_[a|m|c]time fields
+#if !SANITIZER_GO
+#undef st_atime
+#undef st_mtime
+#undef st_ctime
+#endif
+#if defined(SANITIZER_ANDROID)
+// Bionic sys/stat.h defines additional macros
+// for compatibility with the old NDKs and
+// they clash with the kernel_stat structure
+// st_[a|m|c]time_nsec fields.
+#undef st_atime_nsec
+#undef st_mtime_nsec
+#undef st_ctime_nsec
+#endif
+static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) {
+  internal_memset(out, 0, sizeof(*out));
+  out->st_dev = in->st_dev;
+  out->st_ino = in->st_ino;
+  out->st_mode = in->st_mode;
+  out->st_nlink = in->st_nlink;
+  out->st_uid = in->st_uid;
+  out->st_gid = in->st_gid;
+  out->st_rdev = in->st_rdev;
+  out->st_size = in->st_size;
+  out->st_blksize = in->st_blksize;
+  out->st_blocks = in->st_blocks;
+#if defined(__USE_MISC)     || \
+    defined(__USE_XOPEN2K8) || \
+    defined(SANITIZER_ANDROID)
+  out->st_atim.tv_sec = in->st_atime;
+  out->st_atim.tv_nsec = in->st_atime_nsec;
+  out->st_mtim.tv_sec = in->st_mtime;
+  out->st_mtim.tv_nsec = in->st_mtime_nsec;
+  out->st_ctim.tv_sec = in->st_ctime;
+  out->st_ctim.tv_nsec = in->st_ctime_nsec;
+#else
+  out->st_atime = in->st_atime;
+  out->st_atimensec = in->st_atime_nsec;
+  out->st_mtime = in->st_mtime;
+  out->st_mtimensec = in->st_mtime_nsec;
+  out->st_ctime = in->st_ctime;
+  out->st_atimensec = in->st_ctime_nsec;
+#endif
+}
+#endif
+
+uptr internal_stat(const char *path, void *buf) {
+#  if SANITIZER_FREEBSD
+  return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0);
+#  elif SANITIZER_LINUX
+#    if defined(__loongarch__)
+  struct statx bufx;
+  int res = internal_syscall(SYSCALL(statx), AT_FDCWD, (uptr)path,
+                             AT_NO_AUTOMOUNT, STATX_BASIC_STATS, (uptr)&bufx);
+  statx_to_stat(&bufx, (struct stat *)buf);
+  return res;
+#    elif (SANITIZER_WORDSIZE == 64 || SANITIZER_X32 ||    \
+           (defined(__mips__) && _MIPS_SIM == _ABIN32)) && \
+        !SANITIZER_SPARC
+  return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
+                          0);
+#    else
+  struct stat64 buf64;
+  int res = internal_syscall(SYSCALL(fstatat64), AT_FDCWD, (uptr)path,
+                             (uptr)&buf64, 0);
+  stat64_to_stat(&buf64, (struct stat *)buf);
+  return res;
+#    endif
+#  else
+  struct stat64 buf64;
+  int res = internal_syscall(SYSCALL(stat64), path, &buf64);
+  stat64_to_stat(&buf64, (struct stat *)buf);
+  return res;
+#  endif
+}
+
+uptr internal_lstat(const char *path, void *buf) {
+#  if SANITIZER_FREEBSD
+  return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf,
+                          AT_SYMLINK_NOFOLLOW);
+#  elif SANITIZER_LINUX
+#    if defined(__loongarch__)
+  struct statx bufx;
+  int res = internal_syscall(SYSCALL(statx), AT_FDCWD, (uptr)path,
+                             AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT,
+                             STATX_BASIC_STATS, (uptr)&bufx);
+  statx_to_stat(&bufx, (struct stat *)buf);
+  return res;
+#    elif (defined(_LP64) || SANITIZER_X32 ||              \
+           (defined(__mips__) && _MIPS_SIM == _ABIN32)) && \
+        !SANITIZER_SPARC
+  return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
+                          AT_SYMLINK_NOFOLLOW);
+#    else
+  struct stat64 buf64;
+  int res = internal_syscall(SYSCALL(fstatat64), AT_FDCWD, (uptr)path,
+                             (uptr)&buf64, AT_SYMLINK_NOFOLLOW);
+  stat64_to_stat(&buf64, (struct stat *)buf);
+  return res;
+#    endif
+#  else
+  struct stat64 buf64;
+  int res = internal_syscall(SYSCALL(lstat64), path, &buf64);
+  stat64_to_stat(&buf64, (struct stat *)buf);
+  return res;
+#  endif
+}
+
+uptr internal_fstat(fd_t fd, void *buf) {
+#if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
+#if SANITIZER_MIPS64
+  // For mips64, fstat syscall fills buffer in the format of kernel_stat
+  struct kernel_stat kbuf;
+  int res = internal_syscall(SYSCALL(fstat), fd, &kbuf);
+  kernel_stat_to_stat(&kbuf, (struct stat *)buf);
+  return res;
+#      elif SANITIZER_LINUX && defined(__loongarch__)
+  struct statx bufx;
+  int res = internal_syscall(SYSCALL(statx), fd, "", AT_EMPTY_PATH,
+                             STATX_BASIC_STATS, (uptr)&bufx);
+  statx_to_stat(&bufx, (struct stat *)buf);
+  return res;
+#      else
+  return internal_syscall(SYSCALL(fstat), fd, (uptr)buf);
+#      endif
+#else
+  struct stat64 buf64;
+  int res = internal_syscall(SYSCALL(fstat64), fd, &buf64);
+  stat64_to_stat(&buf64, (struct stat *)buf);
+  return res;
+#endif
+}
+
+uptr internal_filesize(fd_t fd) {
+  struct stat st;
+  if (internal_fstat(fd, &st))
+    return -1;
+  return (uptr)st.st_size;
+}
+
+uptr internal_dup(int oldfd) {
+  return internal_syscall(SYSCALL(dup), oldfd);
+}
+
+uptr internal_dup2(int oldfd, int newfd) {
+#    if SANITIZER_LINUX
+  return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0);
+#else
+  return internal_syscall(SYSCALL(dup2), oldfd, newfd);
+#endif
+}
+
+uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
+#    if SANITIZER_LINUX
+  return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf,
+                          bufsize);
+#else
+  return internal_syscall(SYSCALL(readlink), (uptr)path, (uptr)buf, bufsize);
+#endif
+}
+
+uptr internal_unlink(const char *path) {
+#    if SANITIZER_LINUX
+  return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0);
+#else
+  return internal_syscall(SYSCALL(unlink), (uptr)path);
+#endif
+}
+
+uptr internal_rename(const char *oldpath, const char *newpath) {
+#  if (defined(__riscv) || defined(__loongarch__)) && defined(__linux__)
+  return internal_syscall(SYSCALL(renameat2), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
+                          (uptr)newpath, 0);
+#  elif SANITIZER_LINUX
+  return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
+                          (uptr)newpath);
+#  else
+  return internal_syscall(SYSCALL(rename), (uptr)oldpath, (uptr)newpath);
+#  endif
+}
+
+uptr internal_sched_yield() {
+  return internal_syscall(SYSCALL(sched_yield));
+}
+
+void internal_usleep(u64 useconds) {
+  struct timespec ts;
+  ts.tv_sec = useconds / 1000000;
+  ts.tv_nsec = (useconds % 1000000) * 1000;
+  internal_syscall(SYSCALL(nanosleep), &ts, &ts);
+}
+
+uptr internal_execve(const char *filename, char *const argv[],
+                     char *const envp[]) {
+  return internal_syscall(SYSCALL(execve), (uptr)filename, (uptr)argv,
+                          (uptr)envp);
+}
+#endif  // !SANITIZER_SOLARIS && !SANITIZER_NETBSD
+
+#if !SANITIZER_NETBSD
+void internal__exit(int exitcode) {
+#if SANITIZER_FREEBSD || SANITIZER_SOLARIS
+  internal_syscall(SYSCALL(exit), exitcode);
+#else
+  internal_syscall(SYSCALL(exit_group), exitcode);
+#endif
+  Die();  // Unreachable.
+}
+#endif  // !SANITIZER_NETBSD
+
+// ----------------- sanitizer_common.h
+bool FileExists(const char *filename) {
+  if (ShouldMockFailureToOpen(filename))
+    return false;
+  struct stat st;
+  if (internal_stat(filename, &st))
+    return false;
+  // Sanity check: filename is a regular file.
+  return S_ISREG(st.st_mode);
+}
+
+bool DirExists(const char *path) {
+  struct stat st;
+  if (internal_stat(path, &st))
+    return false;
+  return S_ISDIR(st.st_mode);
+}
+
+#  if !SANITIZER_NETBSD
+tid_t GetTid() {
+#if SANITIZER_FREEBSD
+  long Tid;
+  thr_self(&Tid);
+  return Tid;
+#elif SANITIZER_SOLARIS
+  return thr_self();
+#else
+  return internal_syscall(SYSCALL(gettid));
+#endif
+}
+
+int TgKill(pid_t pid, tid_t tid, int sig) {
+#if SANITIZER_LINUX
+  return internal_syscall(SYSCALL(tgkill), pid, tid, sig);
+#elif SANITIZER_FREEBSD
+  return internal_syscall(SYSCALL(thr_kill2), pid, tid, sig);
+#elif SANITIZER_SOLARIS
+  (void)pid;
+  return thr_kill(tid, sig);
+#endif
+}
+#endif
+
+#if SANITIZER_GLIBC
+u64 NanoTime() {
+  kernel_timeval tv;
+  internal_memset(&tv, 0, sizeof(tv));
+  internal_syscall(SYSCALL(gettimeofday), &tv, 0);
+  return (u64)tv.tv_sec * 1000 * 1000 * 1000 + tv.tv_usec * 1000;
+}
+// Used by real_clock_gettime.
+uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp) {
+  return internal_syscall(SYSCALL(clock_gettime), clk_id, tp);
+}
+#elif !SANITIZER_SOLARIS && !SANITIZER_NETBSD
+u64 NanoTime() {
+  struct timespec ts;
+  clock_gettime(CLOCK_REALTIME, &ts);
+  return (u64)ts.tv_sec * 1000 * 1000 * 1000 + ts.tv_nsec;
+}
+#endif
+
+// Like getenv, but reads env directly from /proc (on Linux) or parses the
+// 'environ' array (on some others) and does not use libc. This function
+// should be called first inside __asan_init.
+const char *GetEnv(const char *name) {
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_SOLARIS
+  if (::environ != 0) {
+    uptr NameLen = internal_strlen(name);
+    for (char **Env = ::environ; *Env != 0; Env++) {
+      if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
+        return (*Env) + NameLen + 1;
+    }
+  }
+  return 0;  // Not found.
+#elif SANITIZER_LINUX
+  static char *environ;
+  static uptr len;
+  static bool inited;
+  if (!inited) {
+    inited = true;
+    uptr environ_size;
+    if (!ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, &len))
+      environ = nullptr;
+  }
+  if (!environ || len == 0) return nullptr;
+  uptr namelen = internal_strlen(name);
+  const char *p = environ;
+  while (*p != '\0') {  // will happen at the \0\0 that terminates the buffer
+    // proc file has the format NAME=value\0NAME=value\0NAME=value\0...
+    const char* endp =
+        (char*)internal_memchr(p, '\0', len - (p - environ));
+    if (!endp)  // this entry isn't NUL terminated
+      return nullptr;
+    else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=')  // Match.
+      return p + namelen + 1;  // point after =
+    p = endp + 1;
+  }
+  return nullptr;  // Not found.
+#else
+#error "Unsupported platform"
+#endif
+}
+
+#if !SANITIZER_FREEBSD && !SANITIZER_NETBSD && !SANITIZER_GO
+extern "C" {
+SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end;
+}
+#endif
+
+#if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
+static void ReadNullSepFileToArray(const char *path, char ***arr,
+                                   int arr_size) {
+  char *buff;
+  uptr buff_size;
+  uptr buff_len;
+  *arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray");
+  if (!ReadFileToBuffer(path, &buff, &buff_size, &buff_len, 1024 * 1024)) {
+    (*arr)[0] = nullptr;
+    return;
+  }
+  (*arr)[0] = buff;
+  int count, i;
+  for (count = 1, i = 1; ; i++) {
+    if (buff[i] == 0) {
+      if (buff[i+1] == 0) break;
+      (*arr)[count] = &buff[i+1];
+      CHECK_LE(count, arr_size - 1);  // FIXME: make this more flexible.
+      count++;
+    }
+  }
+  (*arr)[count] = nullptr;
+}
+#endif
+
+static void GetArgsAndEnv(char ***argv, char ***envp) {
+#if SANITIZER_FREEBSD
+  // On FreeBSD, retrieving the argument and environment arrays is done via the
+  // kern.ps_strings sysctl, which returns a pointer to a structure containing
+  // this information. See also <sys/exec.h>.
+  ps_strings *pss;
+  uptr sz = sizeof(pss);
+  if (internal_sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) {
+    Printf("sysctl kern.ps_strings failed\n");
+    Die();
+  }
+  *argv = pss->ps_argvstr;
+  *envp = pss->ps_envstr;
+#elif SANITIZER_NETBSD
+  *argv = __ps_strings->ps_argvstr;
+  *envp = __ps_strings->ps_envstr;
+#else // SANITIZER_FREEBSD
+#if !SANITIZER_GO
+  if (&__libc_stack_end) {
+    uptr* stack_end = (uptr*)__libc_stack_end;
+    // Normally argc can be obtained from *stack_end, however, on ARM glibc's
+    // _start clobbers it:
+    // https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/arm/start.S;hb=refs/heads/release/2.31/master#l75
+    // Do not special-case ARM and infer argc from argv everywhere.
+    int argc = 0;
+    while (stack_end[argc + 1]) argc++;
+    *argv = (char**)(stack_end + 1);
+    *envp = (char**)(stack_end + argc + 2);
+  } else {
+#endif // !SANITIZER_GO
+    static const int kMaxArgv = 2000, kMaxEnvp = 2000;
+    ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv);
+    ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp);
+#if !SANITIZER_GO
+  }
+#endif // !SANITIZER_GO
+#endif // SANITIZER_FREEBSD
+}
+
+char **GetArgv() {
+  char **argv, **envp;
+  GetArgsAndEnv(&argv, &envp);
+  return argv;
+}
+
+char **GetEnviron() {
+  char **argv, **envp;
+  GetArgsAndEnv(&argv, &envp);
+  return envp;
+}
+
+#if !SANITIZER_SOLARIS
+void FutexWait(atomic_uint32_t *p, u32 cmp) {
+#    if SANITIZER_FREEBSD
+  _umtx_op(p, UMTX_OP_WAIT_UINT, cmp, 0, 0);
+#    elif SANITIZER_NETBSD
+  sched_yield();   /* No userspace futex-like synchronization */
+#    else
+  internal_syscall(SYSCALL(futex), (uptr)p, FUTEX_WAIT_PRIVATE, cmp, 0, 0, 0);
+#    endif
+}
+
+void FutexWake(atomic_uint32_t *p, u32 count) {
+#    if SANITIZER_FREEBSD
+  _umtx_op(p, UMTX_OP_WAKE, count, 0, 0);
+#    elif SANITIZER_NETBSD
+                   /* No userspace futex-like synchronization */
+#    else
+  internal_syscall(SYSCALL(futex), (uptr)p, FUTEX_WAKE_PRIVATE, count, 0, 0, 0);
+#    endif
+}
+
+#  endif  // !SANITIZER_SOLARIS
+
+// ----------------- sanitizer_linux.h
+// The actual size of this structure is specified by d_reclen.
+// Note that getdents64 uses a different structure format. We only provide the
+// 32-bit syscall here.
+#if SANITIZER_NETBSD
+// Not used
+#else
+struct linux_dirent {
+#    if SANITIZER_X32 || SANITIZER_LINUX
+  u64 d_ino;
+  u64 d_off;
+#    else
+  unsigned long      d_ino;
+  unsigned long      d_off;
+#    endif
+  unsigned short     d_reclen;
+#    if SANITIZER_LINUX
+  unsigned char      d_type;
+#    endif
+  char               d_name[256];
+};
+#endif
+
+#if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
+// Syscall wrappers.
+uptr internal_ptrace(int request, int pid, void *addr, void *data) {
+  return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr,
+                          (uptr)data);
+}
+
+uptr internal_waitpid(int pid, int *status, int options) {
+  return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options,
+                          0 /* rusage */);
+}
+
+uptr internal_getpid() {
+  return internal_syscall(SYSCALL(getpid));
+}
+
+uptr internal_getppid() {
+  return internal_syscall(SYSCALL(getppid));
+}
+
+int internal_dlinfo(void *handle, int request, void *p) {
+#if SANITIZER_FREEBSD
+  return dlinfo(handle, request, p);
+#else
+  UNIMPLEMENTED();
+#endif
+}
+
+uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
+#if SANITIZER_FREEBSD
+  return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL);
+#    elif SANITIZER_LINUX
+  return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count);
+#    else
+  return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count);
+#    endif
+}
+
+uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
+  return internal_syscall(SYSCALL(lseek), fd, offset, whence);
+}
+
+#if SANITIZER_LINUX
+uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) {
+  return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5);
+}
+#      if defined(__x86_64__)
+#        include <asm/unistd_64.h>
+// Currently internal_arch_prctl() is only needed on x86_64.
+uptr internal_arch_prctl(int option, uptr arg2) {
+  return internal_syscall(__NR_arch_prctl, option, arg2);
+}
+#      endif
+#    endif
+
+uptr internal_sigaltstack(const void *ss, void *oss) {
+  return internal_syscall(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss);
+}
+
+int internal_fork() {
+#    if SANITIZER_LINUX
+#      if SANITIZER_S390
+  return internal_syscall(SYSCALL(clone), 0, SIGCHLD);
+#      else
+  return internal_syscall(SYSCALL(clone), SIGCHLD, 0);
+#      endif
+#    else
+  return internal_syscall(SYSCALL(fork));
+#    endif
+}
+
+#if SANITIZER_FREEBSD
+int internal_sysctl(const int *name, unsigned int namelen, void *oldp,
+                    uptr *oldlenp, const void *newp, uptr newlen) {
+  return internal_syscall(SYSCALL(__sysctl), name, namelen, oldp,
+                          (size_t *)oldlenp, newp, (size_t)newlen);
+}
+
+int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp,
+                          const void *newp, uptr newlen) {
+  // Note: this function can be called during startup, so we need to avoid
+  // calling any interceptable functions. On FreeBSD >= 1300045 sysctlbyname()
+  // is a real syscall, but for older versions it calls sysctlnametomib()
+  // followed by sysctl(). To avoid calling the intercepted version and
+  // asserting if this happens during startup, call the real sysctlnametomib()
+  // followed by internal_sysctl() if the syscall is not available.
+#ifdef SYS___sysctlbyname
+  return internal_syscall(SYSCALL(__sysctlbyname), sname,
+                          internal_strlen(sname), oldp, (size_t *)oldlenp, newp,
+                          (size_t)newlen);
+#else
+  static decltype(sysctlnametomib) *real_sysctlnametomib = nullptr;
+  if (!real_sysctlnametomib)
+    real_sysctlnametomib =
+        (decltype(sysctlnametomib) *)dlsym(RTLD_NEXT, "sysctlnametomib");
+  CHECK(real_sysctlnametomib);
+
+  int oid[CTL_MAXNAME];
+  size_t len = CTL_MAXNAME;
+  if (real_sysctlnametomib(sname, oid, &len) == -1)
+    return (-1);
+  return internal_sysctl(oid, len, oldp, oldlenp, newp, newlen);
+#endif
+}
+#endif
+
+#if SANITIZER_LINUX
+#define SA_RESTORER 0x04000000
+// Doesn't set sa_restorer if the caller did not set it, so use with caution
+//(see below).
+int internal_sigaction_norestorer(int signum, const void *act, void *oldact) {
+  __sanitizer_kernel_sigaction_t k_act, k_oldact;
+  internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t));
+  internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t));
+  const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act;
+  __sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact;
+  if (u_act) {
+    k_act.handler = u_act->handler;
+    k_act.sigaction = u_act->sigaction;
+    internal_memcpy(&k_act.sa_mask, &u_act->sa_mask,
+                    sizeof(__sanitizer_kernel_sigset_t));
+    // Without SA_RESTORER kernel ignores the calls (probably returns EINVAL).
+    k_act.sa_flags = u_act->sa_flags | SA_RESTORER;
+    // FIXME: most often sa_restorer is unset, however the kernel requires it
+    // to point to a valid signal restorer that calls the rt_sigreturn syscall.
+    // If sa_restorer passed to the kernel is NULL, the program may crash upon
+    // signal delivery or fail to unwind the stack in the signal handler.
+    // libc implementation of sigaction() passes its own restorer to
+    // rt_sigaction, so we need to do the same (we'll need to reimplement the
+    // restorers; for x86_64 the restorer address can be obtained from
+    // oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact).
+#if !SANITIZER_ANDROID || !SANITIZER_MIPS32
+    k_act.sa_restorer = u_act->sa_restorer;
+#endif
+  }
+
+  uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum,
+      (uptr)(u_act ? &k_act : nullptr),
+      (uptr)(u_oldact ? &k_oldact : nullptr),
+      (uptr)sizeof(__sanitizer_kernel_sigset_t));
+
+  if ((result == 0) && u_oldact) {
+    u_oldact->handler = k_oldact.handler;
+    u_oldact->sigaction = k_oldact.sigaction;
+    internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask,
+                    sizeof(__sanitizer_kernel_sigset_t));
+    u_oldact->sa_flags = k_oldact.sa_flags;
+#if !SANITIZER_ANDROID || !SANITIZER_MIPS32
+    u_oldact->sa_restorer = k_oldact.sa_restorer;
+#endif
+  }
+  return result;
+}
+#endif  // SANITIZER_LINUX
+
+uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
+                          __sanitizer_sigset_t *oldset) {
+#if SANITIZER_FREEBSD
+  return internal_syscall(SYSCALL(sigprocmask), how, set, oldset);
+#else
+  __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
+  __sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset;
+  return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how, (uptr)k_set,
+                          (uptr)k_oldset, sizeof(__sanitizer_kernel_sigset_t));
+#endif
+}
+
+void internal_sigfillset(__sanitizer_sigset_t *set) {
+  internal_memset(set, 0xff, sizeof(*set));
+}
+
+void internal_sigemptyset(__sanitizer_sigset_t *set) {
+  internal_memset(set, 0, sizeof(*set));
+}
+
+#if SANITIZER_LINUX
+void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
+  signum -= 1;
+  CHECK_GE(signum, 0);
+  CHECK_LT(signum, sizeof(*set) * 8);
+  __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
+  const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
+  const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
+  k_set->sig[idx] &= ~((uptr)1 << bit);
+}
+
+bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
+  signum -= 1;
+  CHECK_GE(signum, 0);
+  CHECK_LT(signum, sizeof(*set) * 8);
+  __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
+  const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
+  const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
+  return k_set->sig[idx] & ((uptr)1 << bit);
+}
+#elif SANITIZER_FREEBSD
+uptr internal_procctl(int type, int id, int cmd, void *data) {
+  return internal_syscall(SYSCALL(procctl), type, id, cmd, data);
+}
+
+void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
+  sigset_t *rset = reinterpret_cast<sigset_t *>(set);
+  sigdelset(rset, signum);
+}
+
+bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
+  sigset_t *rset = reinterpret_cast<sigset_t *>(set);
+  return sigismember(rset, signum);
+}
+#endif
+#endif // !SANITIZER_SOLARIS
+
+#if !SANITIZER_NETBSD
+// ThreadLister implementation.
+ThreadLister::ThreadLister(pid_t pid) : pid_(pid), buffer_(4096) {
+  char task_directory_path[80];
+  internal_snprintf(task_directory_path, sizeof(task_directory_path),
+                    "/proc/%d/task/", pid);
+  descriptor_ = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY);
+  if (internal_iserror(descriptor_)) {
+    Report("Can't open /proc/%d/task for reading.\n", pid);
+  }
+}
+
+ThreadLister::Result ThreadLister::ListThreads(
+    InternalMmapVector<tid_t> *threads) {
+  if (internal_iserror(descriptor_))
+    return Error;
+  internal_lseek(descriptor_, 0, SEEK_SET);
+  threads->clear();
+
+  Result result = Ok;
+  for (bool first_read = true;; first_read = false) {
+    // Resize to max capacity if it was downsized by IsAlive.
+    buffer_.resize(buffer_.capacity());
+    CHECK_GE(buffer_.size(), 4096);
+    uptr read = internal_getdents(
+        descriptor_, (struct linux_dirent *)buffer_.data(), buffer_.size());
+    if (!read)
+      return result;
+    if (internal_iserror(read)) {
+      Report("Can't read directory entries from /proc/%d/task.\n", pid_);
+      return Error;
+    }
+
+    for (uptr begin = (uptr)buffer_.data(), end = begin + read; begin < end;) {
+      struct linux_dirent *entry = (struct linux_dirent *)begin;
+      begin += entry->d_reclen;
+      if (entry->d_ino == 1) {
+        // Inode 1 is for bad blocks and also can be a reason for early return.
+        // Should be emitted if kernel tried to output terminating thread.
+        // See proc_task_readdir implementation in Linux.
+        result = Incomplete;
+      }
+      if (entry->d_ino && *entry->d_name >= '0' && *entry->d_name <= '9')
+        threads->push_back(internal_atoll(entry->d_name));
+    }
+
+    // Now we are going to detect short-read or early EOF. In such cases Linux
+    // can return inconsistent list with missing alive threads.
+    // Code will just remember that the list can be incomplete but it will
+    // continue reads to return as much as possible.
+    if (!first_read) {
+      // The first one was a short-read by definition.
+      result = Incomplete;
+    } else if (read > buffer_.size() - 1024) {
+      // Read was close to the buffer size. So double the size and assume the
+      // worst.
+      buffer_.resize(buffer_.size() * 2);
+      result = Incomplete;
+    } else if (!threads->empty() && !IsAlive(threads->back())) {
+      // Maybe Linux early returned from read on terminated thread (!pid_alive)
+      // and failed to restore read position.
+      // See next_tid and proc_task_instantiate in Linux.
+      result = Incomplete;
+    }
+  }
+}
+
+bool ThreadLister::IsAlive(int tid) {
+  // /proc/%d/task/%d/status uses same call to detect alive threads as
+  // proc_task_readdir. See task_state implementation in Linux.
+  char path[80];
+  internal_snprintf(path, sizeof(path), "/proc/%d/task/%d/status", pid_, tid);
+  if (!ReadFileToVector(path, &buffer_) || buffer_.empty())
+    return false;
+  buffer_.push_back(0);
+  static const char kPrefix[] = "\nPPid:";
+  const char *field = internal_strstr(buffer_.data(), kPrefix);
+  if (!field)
+    return false;
+  field += internal_strlen(kPrefix);
+  return (int)internal_atoll(field) != 0;
+}
+
+ThreadLister::~ThreadLister() {
+  if (!internal_iserror(descriptor_))
+    internal_close(descriptor_);
+}
+#endif
+
+#if SANITIZER_WORDSIZE == 32
+// Take care of unusable kernel area in top gigabyte.
+static uptr GetKernelAreaSize() {
+#if SANITIZER_LINUX && !SANITIZER_X32
+  const uptr gbyte = 1UL << 30;
+
+  // Firstly check if there are writable segments
+  // mapped to top gigabyte (e.g. stack).
+  MemoryMappingLayout proc_maps(/*cache_enabled*/true);
+  if (proc_maps.Error())
+    return 0;
+  MemoryMappedSegment segment;
+  while (proc_maps.Next(&segment)) {
+    if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0;
+  }
+
+#if !SANITIZER_ANDROID
+  // Even if nothing is mapped, top Gb may still be accessible
+  // if we are running on 64-bit kernel.
+  // Uname may report misleading results if personality type
+  // is modified (e.g. under schroot) so check this as well.
+  struct utsname uname_info;
+  int pers = personality(0xffffffffUL);
+  if (!(pers & PER_MASK) && internal_uname(&uname_info) == 0 &&
+      internal_strstr(uname_info.machine, "64"))
+    return 0;
+#endif  // SANITIZER_ANDROID
+
+  // Top gigabyte is reserved for kernel.
+  return gbyte;
+#else
+  return 0;
+#endif  // SANITIZER_LINUX && !SANITIZER_X32
+}
+#endif  // SANITIZER_WORDSIZE == 32
+
+uptr GetMaxVirtualAddress() {
+#if SANITIZER_NETBSD && defined(__x86_64__)
+  return 0x7f7ffffff000ULL;  // (0x00007f8000000000 - PAGE_SIZE)
+#elif SANITIZER_WORDSIZE == 64
+# if defined(__powerpc64__) || defined(__aarch64__) || defined(__loongarch__)
+  // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
+  // We somehow need to figure out which one we are using now and choose
+  // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
+  // Note that with 'ulimit -s unlimited' the stack is moved away from the top
+  // of the address space, so simply checking the stack address is not enough.
+  // This should (does) work for both PowerPC64 Endian modes.
+  // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
+  // loongarch64 also has multiple address space layouts: default is 47-bit.
+  return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
+#elif SANITIZER_RISCV64
+  return (1ULL << 38) - 1;
+# elif SANITIZER_MIPS64
+  return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
+# elif defined(__s390x__)
+  return (1ULL << 53) - 1;  // 0x001fffffffffffffUL;
+#elif defined(__sparc__)
+  return ~(uptr)0;
+# else
+  return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
+# endif
+#else  // SANITIZER_WORDSIZE == 32
+# if defined(__s390__)
+  return (1ULL << 31) - 1;  // 0x7fffffff;
+# else
+  return (1ULL << 32) - 1;  // 0xffffffff;
+# endif
+#endif  // SANITIZER_WORDSIZE
+}
+
+uptr GetMaxUserVirtualAddress() {
+  uptr addr = GetMaxVirtualAddress();
+#if SANITIZER_WORDSIZE == 32 && !defined(__s390__)
+  if (!common_flags()->full_address_space)
+    addr -= GetKernelAreaSize();
+  CHECK_LT(reinterpret_cast<uptr>(&addr), addr);
+#endif
+  return addr;
+}
+
+#if !SANITIZER_ANDROID
+uptr GetPageSize() {
+#if SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__)) && \
+    defined(EXEC_PAGESIZE)
+  return EXEC_PAGESIZE;
+#elif SANITIZER_FREEBSD || SANITIZER_NETBSD
+// Use sysctl as sysconf can trigger interceptors internally.
+  int pz = 0;
+  uptr pzl = sizeof(pz);
+  int mib[2] = {CTL_HW, HW_PAGESIZE};
+  int rv = internal_sysctl(mib, 2, &pz, &pzl, nullptr, 0);
+  CHECK_EQ(rv, 0);
+  return (uptr)pz;
+#elif SANITIZER_USE_GETAUXVAL
+  return getauxval(AT_PAGESZ);
+#else
+  return sysconf(_SC_PAGESIZE);  // EXEC_PAGESIZE may not be trustworthy.
+#endif
+}
+#endif // !SANITIZER_ANDROID
+
+uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
+#if SANITIZER_SOLARIS
+  const char *default_module_name = getexecname();
+  CHECK_NE(default_module_name, NULL);
+  return internal_snprintf(buf, buf_len, "%s", default_module_name);
+#else
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD
+#if SANITIZER_FREEBSD
+  const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
+#else
+  const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
+#endif
+  const char *default_module_name = "kern.proc.pathname";
+  uptr Size = buf_len;
+  bool IsErr =
+      (internal_sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0);
+  int readlink_error = IsErr ? errno : 0;
+  uptr module_name_len = Size;
+#else
+  const char *default_module_name = "/proc/self/exe";
+  uptr module_name_len = internal_readlink(
+      default_module_name, buf, buf_len);
+  int readlink_error;
+  bool IsErr = internal_iserror(module_name_len, &readlink_error);
+#endif  // SANITIZER_SOLARIS
+  if (IsErr) {
+    // We can't read binary name for some reason, assume it's unknown.
+    Report("WARNING: reading executable name failed with errno %d, "
+           "some stack frames may not be symbolized\n", readlink_error);
+    module_name_len = internal_snprintf(buf, buf_len, "%s",
+                                        default_module_name);
+    CHECK_LT(module_name_len, buf_len);
+  }
+  return module_name_len;
+#endif
+}
+
+uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
+#if SANITIZER_LINUX
+  char *tmpbuf;
+  uptr tmpsize;
+  uptr tmplen;
+  if (ReadFileToBuffer("/proc/self/cmdline", &tmpbuf, &tmpsize, &tmplen,
+                       1024 * 1024)) {
+    internal_strncpy(buf, tmpbuf, buf_len);
+    UnmapOrDie(tmpbuf, tmpsize);
+    return internal_strlen(buf);
+  }
+#endif
+  return ReadBinaryName(buf, buf_len);
+}
+
+// Match full names of the form /path/to/base_name{-,.}*
+bool LibraryNameIs(const char *full_name, const char *base_name) {
+  const char *name = full_name;
+  // Strip path.
+  while (*name != '\0') name++;
+  while (name > full_name && *name != '/') name--;
+  if (*name == '/') name++;
+  uptr base_name_length = internal_strlen(base_name);
+  if (internal_strncmp(name, base_name, base_name_length)) return false;
+  return (name[base_name_length] == '-' || name[base_name_length] == '.');
+}
+
+#if !SANITIZER_ANDROID
+// Call cb for each region mapped by map.
+void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) {
+  CHECK_NE(map, nullptr);
+#if !SANITIZER_FREEBSD
+  typedef ElfW(Phdr) Elf_Phdr;
+  typedef ElfW(Ehdr) Elf_Ehdr;
+#endif // !SANITIZER_FREEBSD
+  char *base = (char *)map->l_addr;
+  Elf_Ehdr *ehdr = (Elf_Ehdr *)base;
+  char *phdrs = base + ehdr->e_phoff;
+  char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize;
+
+  // Find the segment with the minimum base so we can "relocate" the p_vaddr
+  // fields.  Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC
+  // objects have a non-zero base.
+  uptr preferred_base = (uptr)-1;
+  for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
+    Elf_Phdr *phdr = (Elf_Phdr *)iter;
+    if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr)
+      preferred_base = (uptr)phdr->p_vaddr;
+  }
+
+  // Compute the delta from the real base to get a relocation delta.
+  sptr delta = (uptr)base - preferred_base;
+  // Now we can figure out what the loader really mapped.
+  for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
+    Elf_Phdr *phdr = (Elf_Phdr *)iter;
+    if (phdr->p_type == PT_LOAD) {
+      uptr seg_start = phdr->p_vaddr + delta;
+      uptr seg_end = seg_start + phdr->p_memsz;
+      // None of these values are aligned.  We consider the ragged edges of the
+      // load command as defined, since they are mapped from the file.
+      seg_start = RoundDownTo(seg_start, GetPageSizeCached());
+      seg_end = RoundUpTo(seg_end, GetPageSizeCached());
+      cb((void *)seg_start, seg_end - seg_start);
+    }
+  }
+}
+#endif
+
+#if SANITIZER_LINUX
+#if defined(__x86_64__)
+// We cannot use glibc's clone wrapper, because it messes with the child
+// task's TLS. It writes the PID and TID of the child task to its thread
+// descriptor, but in our case the child task shares the thread descriptor with
+// the parent (because we don't know how to allocate a new thread
+// descriptor to keep glibc happy). So the stock version of clone(), when
+// used with CLONE_VM, would end up corrupting the parent's thread descriptor.
+uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
+                    int *parent_tidptr, void *newtls, int *child_tidptr) {
+  long long res;
+  if (!fn || !child_stack)
+    return -EINVAL;
+  CHECK_EQ(0, (uptr)child_stack % 16);
+  child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
+  ((unsigned long long *)child_stack)[0] = (uptr)fn;
+  ((unsigned long long *)child_stack)[1] = (uptr)arg;
+  register void *r8 __asm__("r8") = newtls;
+  register int *r10 __asm__("r10") = child_tidptr;
+  __asm__ __volatile__(
+                       /* %rax = syscall(%rax = SYSCALL(clone),
+                        *                %rdi = flags,
+                        *                %rsi = child_stack,
+                        *                %rdx = parent_tidptr,
+                        *                %r8  = new_tls,
+                        *                %r10 = child_tidptr)
+                        */
+                       "syscall\n"
+
+                       /* if (%rax != 0)
+                        *   return;
+                        */
+                       "testq  %%rax,%%rax\n"
+                       "jnz    1f\n"
+
+                       /* In the child. Terminate unwind chain. */
+                       // XXX: We should also terminate the CFI unwind chain
+                       // here. Unfortunately clang 3.2 doesn't support the
+                       // necessary CFI directives, so we skip that part.
+                       "xorq   %%rbp,%%rbp\n"
+
+                       /* Call "fn(arg)". */
+                       "popq   %%rax\n"
+                       "popq   %%rdi\n"
+                       "call   *%%rax\n"
+
+                       /* Call _exit(%rax). */
+                       "movq   %%rax,%%rdi\n"
+                       "movq   %2,%%rax\n"
+                       "syscall\n"
+
+                       /* Return to parent. */
+                     "1:\n"
+                       : "=a" (res)
+                       : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
+                         "S"(child_stack),
+                         "D"(flags),
+                         "d"(parent_tidptr),
+                         "r"(r8),
+                         "r"(r10)
+                       : "memory", "r11", "rcx");
+  return res;
+}
+#elif defined(__mips__)
+uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
+                    int *parent_tidptr, void *newtls, int *child_tidptr) {
+  long long res;
+  if (!fn || !child_stack)
+    return -EINVAL;
+  CHECK_EQ(0, (uptr)child_stack % 16);
+  child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
+  ((unsigned long long *)child_stack)[0] = (uptr)fn;
+  ((unsigned long long *)child_stack)[1] = (uptr)arg;
+  register void *a3 __asm__("$7") = newtls;
+  register int *a4 __asm__("$8") = child_tidptr;
+  // We don't have proper CFI directives here because it requires alot of code
+  // for very marginal benefits.
+  __asm__ __volatile__(
+                       /* $v0 = syscall($v0 = __NR_clone,
+                        * $a0 = flags,
+                        * $a1 = child_stack,
+                        * $a2 = parent_tidptr,
+                        * $a3 = new_tls,
+                        * $a4 = child_tidptr)
+                        */
+                       ".cprestore 16;\n"
+                       "move $4,%1;\n"
+                       "move $5,%2;\n"
+                       "move $6,%3;\n"
+                       "move $7,%4;\n"
+                       /* Store the fifth argument on stack
+                        * if we are using 32-bit abi.
+                        */
+#if SANITIZER_WORDSIZE == 32
+                       "lw %5,16($29);\n"
+#else
+                       "move $8,%5;\n"
+#endif
+                       "li $2,%6;\n"
+                       "syscall;\n"
+
+                       /* if ($v0 != 0)
+                        * return;
+                        */
+                       "bnez $2,1f;\n"
+
+                       /* Call "fn(arg)". */
+#if SANITIZER_WORDSIZE == 32
+#ifdef __BIG_ENDIAN__
+                       "lw $25,4($29);\n"
+                       "lw $4,12($29);\n"
+#else
+                       "lw $25,0($29);\n"
+                       "lw $4,8($29);\n"
+#endif
+#else
+                       "ld $25,0($29);\n"
+                       "ld $4,8($29);\n"
+#endif
+                       "jal $25;\n"
+
+                       /* Call _exit($v0). */
+                       "move $4,$2;\n"
+                       "li $2,%7;\n"
+                       "syscall;\n"
+
+                       /* Return to parent. */
+                     "1:\n"
+                       : "=r" (res)
+                       : "r"(flags),
+                         "r"(child_stack),
+                         "r"(parent_tidptr),
+                         "r"(a3),
+                         "r"(a4),
+                         "i"(__NR_clone),
+                         "i"(__NR_exit)
+                       : "memory", "$29" );
+  return res;
+}
+#elif SANITIZER_RISCV64
+uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
+                    int *parent_tidptr, void *newtls, int *child_tidptr) {
+  if (!fn || !child_stack)
+    return -EINVAL;
+
+  CHECK_EQ(0, (uptr)child_stack % 16);
+
+  register int res __asm__("a0");
+  register int __flags __asm__("a0") = flags;
+  register void *__stack __asm__("a1") = child_stack;
+  register int *__ptid __asm__("a2") = parent_tidptr;
+  register void *__tls __asm__("a3") = newtls;
+  register int *__ctid __asm__("a4") = child_tidptr;
+  register int (*__fn)(void *) __asm__("a5") = fn;
+  register void *__arg __asm__("a6") = arg;
+  register int nr_clone __asm__("a7") = __NR_clone;
+
+  __asm__ __volatile__(
+      "ecall\n"
+
+      /* if (a0 != 0)
+       *   return a0;
+       */
+      "bnez a0, 1f\n"
+
+      // In the child, now. Call "fn(arg)".
+      "mv a0, a6\n"
+      "jalr a5\n"
+
+      // Call _exit(a0).
+      "addi a7, zero, %9\n"
+      "ecall\n"
+      "1:\n"
+
+      : "=r"(res)
+      : "0"(__flags), "r"(__stack), "r"(__ptid), "r"(__tls), "r"(__ctid),
+        "r"(__fn), "r"(__arg), "r"(nr_clone), "i"(__NR_exit)
+      : "memory");
+  return res;
+}
+#elif defined(__aarch64__)
+uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
+                    int *parent_tidptr, void *newtls, int *child_tidptr) {
+  register long long res __asm__("x0");
+  if (!fn || !child_stack)
+    return -EINVAL;
+  CHECK_EQ(0, (uptr)child_stack % 16);
+  child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
+  ((unsigned long long *)child_stack)[0] = (uptr)fn;
+  ((unsigned long long *)child_stack)[1] = (uptr)arg;
+
+  register int (*__fn)(void *)  __asm__("x0") = fn;
+  register void *__stack __asm__("x1") = child_stack;
+  register int   __flags __asm__("x2") = flags;
+  register void *__arg   __asm__("x3") = arg;
+  register int  *__ptid  __asm__("x4") = parent_tidptr;
+  register void *__tls   __asm__("x5") = newtls;
+  register int  *__ctid  __asm__("x6") = child_tidptr;
+
+  __asm__ __volatile__(
+                       "mov x0,x2\n" /* flags  */
+                       "mov x2,x4\n" /* ptid  */
+                       "mov x3,x5\n" /* tls  */
+                       "mov x4,x6\n" /* ctid  */
+                       "mov x8,%9\n" /* clone  */
+
+                       "svc 0x0\n"
+
+                       /* if (%r0 != 0)
+                        *   return %r0;
+                        */
+                       "cmp x0, #0\n"
+                       "bne 1f\n"
+
+                       /* In the child, now. Call "fn(arg)". */
+                       "ldp x1, x0, [sp], #16\n"
+                       "blr x1\n"
+
+                       /* Call _exit(%r0).  */
+                       "mov x8, %10\n"
+                       "svc 0x0\n"
+                     "1:\n"
+
+                       : "=r" (res)
+                       : "i"(-EINVAL),
+                         "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg),
+                         "r"(__ptid), "r"(__tls), "r"(__ctid),
+                         "i"(__NR_clone), "i"(__NR_exit)
+                       : "x30", "memory");
+  return res;
+}
+#elif SANITIZER_LOONGARCH64
+uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
+                    int *parent_tidptr, void *newtls, int *child_tidptr) {
+  if (!fn || !child_stack)
+    return -EINVAL;
+
+  CHECK_EQ(0, (uptr)child_stack % 16);
+
+  register int res __asm__("$a0");
+  register int __flags __asm__("$a0") = flags;
+  register void *__stack __asm__("$a1") = child_stack;
+  register int *__ptid __asm__("$a2") = parent_tidptr;
+  register int *__ctid __asm__("$a3") = child_tidptr;
+  register void *__tls __asm__("$a4") = newtls;
+  register int (*__fn)(void *) __asm__("$a5") = fn;
+  register void *__arg __asm__("$a6") = arg;
+  register int nr_clone __asm__("$a7") = __NR_clone;
+
+  __asm__ __volatile__(
+      "syscall 0\n"
+
+      // if ($a0 != 0)
+      //   return $a0;
+      "bnez $a0, 1f\n"
+
+      // In the child, now. Call "fn(arg)".
+      "move $a0, $a6\n"
+      "jirl $ra, $a5, 0\n"
+
+      // Call _exit($a0).
+      "addi.d $a7, $zero, %9\n"
+      "syscall 0\n"
+
+      "1:\n"
+
+      : "=r"(res)
+      : "0"(__flags), "r"(__stack), "r"(__ptid), "r"(__ctid), "r"(__tls),
+        "r"(__fn), "r"(__arg), "r"(nr_clone), "i"(__NR_exit)
+      : "memory", "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7", "$t8");
+  return res;
+}
+#elif defined(__powerpc64__)
+uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
+                   int *parent_tidptr, void *newtls, int *child_tidptr) {
+  long long res;
+// Stack frame structure.
+#if SANITIZER_PPC64V1
+//   Back chain == 0        (SP + 112)
+// Frame (112 bytes):
+//   Parameter save area    (SP + 48), 8 doublewords
+//   TOC save area          (SP + 40)
+//   Link editor doubleword (SP + 32)
+//   Compiler doubleword    (SP + 24)
+//   LR save area           (SP + 16)
+//   CR save area           (SP + 8)
+//   Back chain             (SP + 0)
+# define FRAME_SIZE 112
+# define FRAME_TOC_SAVE_OFFSET 40
+#elif SANITIZER_PPC64V2
+//   Back chain == 0        (SP + 32)
+// Frame (32 bytes):
+//   TOC save area          (SP + 24)
+//   LR save area           (SP + 16)
+//   CR save area           (SP + 8)
+//   Back chain             (SP + 0)
+# define FRAME_SIZE 32
+# define FRAME_TOC_SAVE_OFFSET 24
+#else
+# error "Unsupported PPC64 ABI"
+#endif
+  if (!fn || !child_stack)
+    return -EINVAL;
+  CHECK_EQ(0, (uptr)child_stack % 16);
+
+  register int (*__fn)(void *) __asm__("r3") = fn;
+  register void *__cstack      __asm__("r4") = child_stack;
+  register int __flags         __asm__("r5") = flags;
+  register void *__arg         __asm__("r6") = arg;
+  register int *__ptidptr      __asm__("r7") = parent_tidptr;
+  register void *__newtls      __asm__("r8") = newtls;
+  register int *__ctidptr      __asm__("r9") = child_tidptr;
+
+ __asm__ __volatile__(
+           /* fn and arg are saved across the syscall */
+           "mr 28, %5\n\t"
+           "mr 27, %8\n\t"
+
+           /* syscall
+             r0 == __NR_clone
+             r3 == flags
+             r4 == child_stack
+             r5 == parent_tidptr
+             r6 == newtls
+             r7 == child_tidptr */
+           "mr 3, %7\n\t"
+           "mr 5, %9\n\t"
+           "mr 6, %10\n\t"
+           "mr 7, %11\n\t"
+           "li 0, %3\n\t"
+           "sc\n\t"
+
+           /* Test if syscall was successful */
+           "cmpdi  cr1, 3, 0\n\t"
+           "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t"
+           "bne-   cr1, 1f\n\t"
+
+           /* Set up stack frame */
+           "li    29, 0\n\t"
+           "stdu  29, -8(1)\n\t"
+           "stdu  1, -%12(1)\n\t"
+           /* Do the function call */
+           "std   2, %13(1)\n\t"
+#if SANITIZER_PPC64V1
+           "ld    0, 0(28)\n\t"
+           "ld    2, 8(28)\n\t"
+           "mtctr 0\n\t"
+#elif SANITIZER_PPC64V2
+           "mr    12, 28\n\t"
+           "mtctr 12\n\t"
+#else
+# error "Unsupported PPC64 ABI"
+#endif
+           "mr    3, 27\n\t"
+           "bctrl\n\t"
+           "ld    2, %13(1)\n\t"
+
+           /* Call _exit(r3) */
+           "li 0, %4\n\t"
+           "sc\n\t"
+
+           /* Return to parent */
+           "1:\n\t"
+           "mr %0, 3\n\t"
+             : "=r" (res)
+             : "0" (-1),
+               "i" (EINVAL),
+               "i" (__NR_clone),
+               "i" (__NR_exit),
+               "r" (__fn),
+               "r" (__cstack),
+               "r" (__flags),
+               "r" (__arg),
+               "r" (__ptidptr),
+               "r" (__newtls),
+               "r" (__ctidptr),
+               "i" (FRAME_SIZE),
+               "i" (FRAME_TOC_SAVE_OFFSET)
+             : "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29");
+  return res;
+}
+#elif defined(__i386__)
+uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
+                    int *parent_tidptr, void *newtls, int *child_tidptr) {
+  int res;
+  if (!fn || !child_stack)
+    return -EINVAL;
+  CHECK_EQ(0, (uptr)child_stack % 16);
+  child_stack = (char *)child_stack - 7 * sizeof(unsigned int);
+  ((unsigned int *)child_stack)[0] = (uptr)flags;
+  ((unsigned int *)child_stack)[1] = (uptr)0;
+  ((unsigned int *)child_stack)[2] = (uptr)fn;
+  ((unsigned int *)child_stack)[3] = (uptr)arg;
+  __asm__ __volatile__(
+                       /* %eax = syscall(%eax = SYSCALL(clone),
+                        *                %ebx = flags,
+                        *                %ecx = child_stack,
+                        *                %edx = parent_tidptr,
+                        *                %esi  = new_tls,
+                        *                %edi = child_tidptr)
+                        */
+
+                        /* Obtain flags */
+                        "movl    (%%ecx), %%ebx\n"
+                        /* Do the system call */
+                        "pushl   %%ebx\n"
+                        "pushl   %%esi\n"
+                        "pushl   %%edi\n"
+                        /* Remember the flag value.  */
+                        "movl    %%ebx, (%%ecx)\n"
+                        "int     $0x80\n"
+                        "popl    %%edi\n"
+                        "popl    %%esi\n"
+                        "popl    %%ebx\n"
+
+                        /* if (%eax != 0)
+                         *   return;
+                         */
+
+                        "test    %%eax,%%eax\n"
+                        "jnz    1f\n"
+
+                        /* terminate the stack frame */
+                        "xorl   %%ebp,%%ebp\n"
+                        /* Call FN. */
+                        "call    *%%ebx\n"
+#ifdef PIC
+                        "call    here\n"
+                        "here:\n"
+                        "popl    %%ebx\n"
+                        "addl    $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n"
+#endif
+                        /* Call exit */
+                        "movl    %%eax, %%ebx\n"
+                        "movl    %2, %%eax\n"
+                        "int     $0x80\n"
+                        "1:\n"
+                       : "=a" (res)
+                       : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
+                         "c"(child_stack),
+                         "d"(parent_tidptr),
+                         "S"(newtls),
+                         "D"(child_tidptr)
+                       : "memory");
+  return res;
+}
+#elif defined(__arm__)
+uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
+                    int *parent_tidptr, void *newtls, int *child_tidptr) {
+  unsigned int res;
+  if (!fn || !child_stack)
+    return -EINVAL;
+  child_stack = (char *)child_stack - 2 * sizeof(unsigned int);
+  ((unsigned int *)child_stack)[0] = (uptr)fn;
+  ((unsigned int *)child_stack)[1] = (uptr)arg;
+  register int r0 __asm__("r0") = flags;
+  register void *r1 __asm__("r1") = child_stack;
+  register int *r2 __asm__("r2") = parent_tidptr;
+  register void *r3 __asm__("r3") = newtls;
+  register int *r4 __asm__("r4") = child_tidptr;
+  register int r7 __asm__("r7") = __NR_clone;
+
+#if __ARM_ARCH > 4 || defined (__ARM_ARCH_4T__)
+# define ARCH_HAS_BX
+#endif
+#if __ARM_ARCH > 4
+# define ARCH_HAS_BLX
+#endif
+
+#ifdef ARCH_HAS_BX
+# ifdef ARCH_HAS_BLX
+#  define BLX(R) "blx "  #R "\n"
+# else
+#  define BLX(R) "mov lr, pc; bx " #R "\n"
+# endif
+#else
+# define BLX(R)  "mov lr, pc; mov pc," #R "\n"
+#endif
+
+  __asm__ __volatile__(
+                       /* %r0 = syscall(%r7 = SYSCALL(clone),
+                        *               %r0 = flags,
+                        *               %r1 = child_stack,
+                        *               %r2 = parent_tidptr,
+                        *               %r3  = new_tls,
+                        *               %r4 = child_tidptr)
+                        */
+
+                       /* Do the system call */
+                       "swi 0x0\n"
+
+                       /* if (%r0 != 0)
+                        *   return %r0;
+                        */
+                       "cmp r0, #0\n"
+                       "bne 1f\n"
+
+                       /* In the child, now. Call "fn(arg)". */
+                       "ldr r0, [sp, #4]\n"
+                       "ldr ip, [sp], #8\n"
+                       BLX(ip)
+                       /* Call _exit(%r0). */
+                       "mov r7, %7\n"
+                       "swi 0x0\n"
+                       "1:\n"
+                       "mov %0, r0\n"
+                       : "=r"(res)
+                       : "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7),
+                         "i"(__NR_exit)
+                       : "memory");
+  return res;
+}
+#endif
+#endif  // SANITIZER_LINUX
+
+#if SANITIZER_LINUX
+int internal_uname(struct utsname *buf) {
+  return internal_syscall(SYSCALL(uname), buf);
+}
+#endif
+
+#if SANITIZER_ANDROID
+#if __ANDROID_API__ < 21
+extern "C" __attribute__((weak)) int dl_iterate_phdr(
+    int (*)(struct dl_phdr_info *, size_t, void *), void *);
+#endif
+
+static int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size,
+                                   void *data) {
+  // Any name starting with "lib" indicates a bug in L where library base names
+  // are returned instead of paths.
+  if (info->dlpi_name && info->dlpi_name[0] == 'l' &&
+      info->dlpi_name[1] == 'i' && info->dlpi_name[2] == 'b') {
+    *(bool *)data = true;
+    return 1;
+  }
+  return 0;
+}
+
+static atomic_uint32_t android_api_level;
+
+static AndroidApiLevel AndroidDetectApiLevelStatic() {
+#if __ANDROID_API__ <= 19
+  return ANDROID_KITKAT;
+#elif __ANDROID_API__ <= 22
+  return ANDROID_LOLLIPOP_MR1;
+#else
+  return ANDROID_POST_LOLLIPOP;
+#endif
+}
+
+static AndroidApiLevel AndroidDetectApiLevel() {
+  if (!&dl_iterate_phdr)
+    return ANDROID_KITKAT; // K or lower
+  bool base_name_seen = false;
+  dl_iterate_phdr(dl_iterate_phdr_test_cb, &base_name_seen);
+  if (base_name_seen)
+    return ANDROID_LOLLIPOP_MR1; // L MR1
+  return ANDROID_POST_LOLLIPOP;   // post-L
+  // Plain L (API level 21) is completely broken wrt ASan and not very
+  // interesting to detect.
+}
+
+extern "C" __attribute__((weak)) void* _DYNAMIC;
+
+AndroidApiLevel AndroidGetApiLevel() {
+  AndroidApiLevel level =
+      (AndroidApiLevel)atomic_load(&android_api_level, memory_order_relaxed);
+  if (level) return level;
+  level = &_DYNAMIC == nullptr ? AndroidDetectApiLevelStatic()
+                               : AndroidDetectApiLevel();
+  atomic_store(&android_api_level, level, memory_order_relaxed);
+  return level;
+}
+
+#endif
+
+static HandleSignalMode GetHandleSignalModeImpl(int signum) {
+  switch (signum) {
+    case SIGABRT:
+      return common_flags()->handle_abort;
+    case SIGILL:
+      return common_flags()->handle_sigill;
+    case SIGTRAP:
+      return common_flags()->handle_sigtrap;
+    case SIGFPE:
+      return common_flags()->handle_sigfpe;
+    case SIGSEGV:
+      return common_flags()->handle_segv;
+    case SIGBUS:
+      return common_flags()->handle_sigbus;
+  }
+  return kHandleSignalNo;
+}
+
+HandleSignalMode GetHandleSignalMode(int signum) {
+  HandleSignalMode result = GetHandleSignalModeImpl(signum);
+  if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler)
+    return kHandleSignalExclusive;
+  return result;
+}
+
+#if !SANITIZER_GO
+void *internal_start_thread(void *(*func)(void *arg), void *arg) {
+  if (&real_pthread_create == 0)
+    return nullptr;
+  // Start the thread with signals blocked, otherwise it can steal user signals.
+  ScopedBlockSignals block(nullptr);
+  void *th;
+  real_pthread_create(&th, nullptr, func, arg);
+  return th;
+}
+
+void internal_join_thread(void *th) {
+  if (&real_pthread_join)
+    real_pthread_join(th, nullptr);
+}
+#else
+void *internal_start_thread(void *(*func)(void *), void *arg) { return 0; }
+
+void internal_join_thread(void *th) {}
+#endif
+
+#if SANITIZER_LINUX && defined(__aarch64__)
+// Android headers in the older NDK releases miss this definition.
+struct __sanitizer_esr_context {
+  struct _aarch64_ctx head;
+  uint64_t esr;
+};
+
+static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
+  static const u32 kEsrMagic = 0x45535201;
+  u8 *aux = reinterpret_cast<u8 *>(ucontext->uc_mcontext.__reserved);
+  while (true) {
+    _aarch64_ctx *ctx = (_aarch64_ctx *)aux;
+    if (ctx->size == 0) break;
+    if (ctx->magic == kEsrMagic) {
+      *esr = ((__sanitizer_esr_context *)ctx)->esr;
+      return true;
+    }
+    aux += ctx->size;
+  }
+  return false;
+}
+#elif SANITIZER_FREEBSD && defined(__aarch64__)
+// FreeBSD doesn't provide ESR in the ucontext.
+static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
+  return false;
+}
+#endif
+
+using Context = ucontext_t;
+
+SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
+  Context *ucontext = (Context *)context;
+#if defined(__x86_64__) || defined(__i386__)
+  static const uptr PF_WRITE = 1U << 1;
+#if SANITIZER_FREEBSD
+  uptr err = ucontext->uc_mcontext.mc_err;
+#elif SANITIZER_NETBSD
+  uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR];
+#elif SANITIZER_SOLARIS && defined(__i386__)
+  const int Err = 13;
+  uptr err = ucontext->uc_mcontext.gregs[Err];
+#else
+  uptr err = ucontext->uc_mcontext.gregs[REG_ERR];
+#endif // SANITIZER_FREEBSD
+  return err & PF_WRITE ? Write : Read;
+#elif defined(__mips__)
+  uint32_t *exception_source;
+  uint32_t faulty_instruction;
+  uint32_t op_code;
+
+  exception_source = (uint32_t *)ucontext->uc_mcontext.pc;
+  faulty_instruction = (uint32_t)(*exception_source);
+
+  op_code = (faulty_instruction >> 26) & 0x3f;
+
+  // FIXME: Add support for FPU, microMIPS, DSP, MSA memory instructions.
+  switch (op_code) {
+    case 0x28:  // sb
+    case 0x29:  // sh
+    case 0x2b:  // sw
+    case 0x3f:  // sd
+#if __mips_isa_rev < 6
+    case 0x2c:  // sdl
+    case 0x2d:  // sdr
+    case 0x2a:  // swl
+    case 0x2e:  // swr
+#endif
+      return SignalContext::Write;
+
+    case 0x20:  // lb
+    case 0x24:  // lbu
+    case 0x21:  // lh
+    case 0x25:  // lhu
+    case 0x23:  // lw
+    case 0x27:  // lwu
+    case 0x37:  // ld
+#if __mips_isa_rev < 6
+    case 0x1a:  // ldl
+    case 0x1b:  // ldr
+    case 0x22:  // lwl
+    case 0x26:  // lwr
+#endif
+      return SignalContext::Read;
+#if __mips_isa_rev == 6
+    case 0x3b:  // pcrel
+      op_code = (faulty_instruction >> 19) & 0x3;
+      switch (op_code) {
+        case 0x1:  // lwpc
+        case 0x2:  // lwupc
+          return SignalContext::Read;
+      }
+#endif
+  }
+  return SignalContext::Unknown;
+#elif defined(__arm__)
+  static const uptr FSR_WRITE = 1U << 11;
+  uptr fsr = ucontext->uc_mcontext.error_code;
+  return fsr & FSR_WRITE ? Write : Read;
+#elif defined(__aarch64__)
+  static const u64 ESR_ELx_WNR = 1U << 6;
+  u64 esr;
+  if (!Aarch64GetESR(ucontext, &esr)) return Unknown;
+  return esr & ESR_ELx_WNR ? Write : Read;
+#elif defined(__loongarch__)
+  u32 flags = ucontext->uc_mcontext.__flags;
+  if (flags & SC_ADDRERR_RD)
+    return SignalContext::Read;
+  if (flags & SC_ADDRERR_WR)
+    return SignalContext::Write;
+  return SignalContext::Unknown;
+#elif defined(__sparc__)
+  // Decode the instruction to determine the access type.
+  // From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype).
+#if SANITIZER_SOLARIS
+  uptr pc = ucontext->uc_mcontext.gregs[REG_PC];
+#else
+  // Historical BSDism here.
+  struct sigcontext *scontext = (struct sigcontext *)context;
+#if defined(__arch64__)
+  uptr pc = scontext->sigc_regs.tpc;
+#else
+  uptr pc = scontext->si_regs.pc;
+#endif
+#endif
+  u32 instr = *(u32 *)pc;
+  return (instr >> 21) & 1 ? Write: Read;
+#elif defined(__riscv)
+#if SANITIZER_FREEBSD
+  unsigned long pc = ucontext->uc_mcontext.mc_gpregs.gp_sepc;
+#else
+  unsigned long pc = ucontext->uc_mcontext.__gregs[REG_PC];
+#endif
+  unsigned faulty_instruction = *(uint16_t *)pc;
+
+#if defined(__riscv_compressed)
+  if ((faulty_instruction & 0x3) != 0x3) {  // it's a compressed instruction
+    // set op_bits to the instruction bits [1, 0, 15, 14, 13]
+    unsigned op_bits =
+        ((faulty_instruction & 0x3) << 3) | (faulty_instruction >> 13);
+    unsigned rd = faulty_instruction & 0xF80;  // bits 7-11, inclusive
+    switch (op_bits) {
+      case 0b10'010:  // c.lwsp (rd != x0)
+#if __riscv_xlen == 64
+      case 0b10'011:  // c.ldsp (rd != x0)
+#endif
+        return rd ? SignalContext::Read : SignalContext::Unknown;
+      case 0b00'010:  // c.lw
+#if __riscv_flen >= 32 && __riscv_xlen == 32
+      case 0b10'011:  // c.flwsp
+#endif
+#if __riscv_flen >= 32 || __riscv_xlen == 64
+      case 0b00'011:  // c.flw / c.ld
+#endif
+#if __riscv_flen == 64
+      case 0b00'001:  // c.fld
+      case 0b10'001:  // c.fldsp
+#endif
+        return SignalContext::Read;
+      case 0b00'110:  // c.sw
+      case 0b10'110:  // c.swsp
+#if __riscv_flen >= 32 || __riscv_xlen == 64
+      case 0b00'111:  // c.fsw / c.sd
+      case 0b10'111:  // c.fswsp / c.sdsp
+#endif
+#if __riscv_flen == 64
+      case 0b00'101:  // c.fsd
+      case 0b10'101:  // c.fsdsp
+#endif
+        return SignalContext::Write;
+      default:
+        return SignalContext::Unknown;
+    }
+  }
+#endif
+
+  unsigned opcode = faulty_instruction & 0x7f;         // lower 7 bits
+  unsigned funct3 = (faulty_instruction >> 12) & 0x7;  // bits 12-14, inclusive
+  switch (opcode) {
+    case 0b0000011:  // loads
+      switch (funct3) {
+        case 0b000:  // lb
+        case 0b001:  // lh
+        case 0b010:  // lw
+#if __riscv_xlen == 64
+        case 0b011:  // ld
+#endif
+        case 0b100:  // lbu
+        case 0b101:  // lhu
+          return SignalContext::Read;
+        default:
+          return SignalContext::Unknown;
+      }
+    case 0b0100011:  // stores
+      switch (funct3) {
+        case 0b000:  // sb
+        case 0b001:  // sh
+        case 0b010:  // sw
+#if __riscv_xlen == 64
+        case 0b011:  // sd
+#endif
+          return SignalContext::Write;
+        default:
+          return SignalContext::Unknown;
+      }
+#if __riscv_flen >= 32
+    case 0b0000111:  // floating-point loads
+      switch (funct3) {
+        case 0b010:  // flw
+#if __riscv_flen == 64
+        case 0b011:  // fld
+#endif
+          return SignalContext::Read;
+        default:
+          return SignalContext::Unknown;
+      }
+    case 0b0100111:  // floating-point stores
+      switch (funct3) {
+        case 0b010:  // fsw
+#if __riscv_flen == 64
+        case 0b011:  // fsd
+#endif
+          return SignalContext::Write;
+        default:
+          return SignalContext::Unknown;
+      }
+#endif
+    default:
+      return SignalContext::Unknown;
+  }
+#else
+  (void)ucontext;
+  return Unknown;  // FIXME: Implement.
+#endif
+}
+
+bool SignalContext::IsTrueFaultingAddress() const {
+  auto si = static_cast<const siginfo_t *>(siginfo);
+  // SIGSEGV signals without a true fault address have si_code set to 128.
+  return si->si_signo == SIGSEGV && si->si_code != 128;
+}
+
+void SignalContext::DumpAllRegisters(void *context) {
+  // FIXME: Implement this.
+}
+
+static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
+#if SANITIZER_NETBSD
+  // This covers all NetBSD architectures
+  ucontext_t *ucontext = (ucontext_t *)context;
+  *pc = _UC_MACHINE_PC(ucontext);
+  *bp = _UC_MACHINE_FP(ucontext);
+  *sp = _UC_MACHINE_SP(ucontext);
+#elif defined(__arm__)
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.arm_pc;
+  *bp = ucontext->uc_mcontext.arm_fp;
+  *sp = ucontext->uc_mcontext.arm_sp;
+#elif defined(__aarch64__)
+# if SANITIZER_FREEBSD
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.mc_gpregs.gp_elr;
+  *bp = ucontext->uc_mcontext.mc_gpregs.gp_x[29];
+  *sp = ucontext->uc_mcontext.mc_gpregs.gp_sp;
+# else
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.pc;
+  *bp = ucontext->uc_mcontext.regs[29];
+  *sp = ucontext->uc_mcontext.sp;
+# endif
+#elif defined(__hppa__)
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.sc_iaoq[0];
+  /* GCC uses %r3 whenever a frame pointer is needed.  */
+  *bp = ucontext->uc_mcontext.sc_gr[3];
+  *sp = ucontext->uc_mcontext.sc_gr[30];
+#elif defined(__x86_64__)
+# if SANITIZER_FREEBSD
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.mc_rip;
+  *bp = ucontext->uc_mcontext.mc_rbp;
+  *sp = ucontext->uc_mcontext.mc_rsp;
+# else
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.gregs[REG_RIP];
+  *bp = ucontext->uc_mcontext.gregs[REG_RBP];
+  *sp = ucontext->uc_mcontext.gregs[REG_RSP];
+# endif
+#elif defined(__i386__)
+# if SANITIZER_FREEBSD
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.mc_eip;
+  *bp = ucontext->uc_mcontext.mc_ebp;
+  *sp = ucontext->uc_mcontext.mc_esp;
+# else
+  ucontext_t *ucontext = (ucontext_t*)context;
+# if SANITIZER_SOLARIS
+  /* Use the numeric values: the symbolic ones are undefined by llvm
+     include/llvm/Support/Solaris.h.  */
+# ifndef REG_EIP
+#  define REG_EIP 14 // REG_PC
+# endif
+# ifndef REG_EBP
+#  define REG_EBP  6 // REG_FP
+# endif
+# ifndef REG_UESP
+#  define REG_UESP 17 // REG_SP
+# endif
+# endif
+  *pc = ucontext->uc_mcontext.gregs[REG_EIP];
+  *bp = ucontext->uc_mcontext.gregs[REG_EBP];
+  *sp = ucontext->uc_mcontext.gregs[REG_UESP];
+# endif
+#elif defined(__powerpc__) || defined(__powerpc64__)
+#    if SANITIZER_FREEBSD
+  ucontext_t *ucontext = (ucontext_t *)context;
+  *pc = ucontext->uc_mcontext.mc_srr0;
+  *sp = ucontext->uc_mcontext.mc_frame[1];
+  *bp = ucontext->uc_mcontext.mc_frame[31];
+#    else
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.regs->nip;
+  *sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
+  // The powerpc{,64}-linux ABIs do not specify r31 as the frame
+  // pointer, but GCC always uses r31 when we need a frame pointer.
+  *bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
+#    endif
+#elif defined(__sparc__)
+#if defined(__arch64__) || defined(__sparcv9)
+#define STACK_BIAS 2047
+#else
+#define STACK_BIAS 0
+# endif
+# if SANITIZER_SOLARIS
+  ucontext_t *ucontext = (ucontext_t *)context;
+  *pc = ucontext->uc_mcontext.gregs[REG_PC];
+  *sp = ucontext->uc_mcontext.gregs[REG_O6] + STACK_BIAS;
+#else
+  // Historical BSDism here.
+  struct sigcontext *scontext = (struct sigcontext *)context;
+#if defined(__arch64__)
+  *pc = scontext->sigc_regs.tpc;
+  *sp = scontext->sigc_regs.u_regs[14] + STACK_BIAS;
+#else
+  *pc = scontext->si_regs.pc;
+  *sp = scontext->si_regs.u_regs[14];
+#endif
+# endif
+  *bp = (uptr)((uhwptr *)*sp)[14] + STACK_BIAS;
+#elif defined(__mips__)
+  ucontext_t *ucontext = (ucontext_t*)context;
+  *pc = ucontext->uc_mcontext.pc;
+  *bp = ucontext->uc_mcontext.gregs[30];
+  *sp = ucontext->uc_mcontext.gregs[29];
+#elif defined(__s390__)
+  ucontext_t *ucontext = (ucontext_t*)context;
+# if defined(__s390x__)
+  *pc = ucontext->uc_mcontext.psw.addr;
+# else
+  *pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff;
+# endif
+  *bp = ucontext->uc_mcontext.gregs[11];
+  *sp = ucontext->uc_mcontext.gregs[15];
+#elif defined(__riscv)
+  ucontext_t *ucontext = (ucontext_t*)context;
+#    if SANITIZER_FREEBSD
+  *pc = ucontext->uc_mcontext.mc_gpregs.gp_sepc;
+  *bp = ucontext->uc_mcontext.mc_gpregs.gp_s[0];
+  *sp = ucontext->uc_mcontext.mc_gpregs.gp_sp;
+#    else
+  *pc = ucontext->uc_mcontext.__gregs[REG_PC];
+  *bp = ucontext->uc_mcontext.__gregs[REG_S0];
+  *sp = ucontext->uc_mcontext.__gregs[REG_SP];
+#    endif
+#  elif defined(__hexagon__)
+  ucontext_t *ucontext = (ucontext_t *)context;
+  *pc = ucontext->uc_mcontext.pc;
+  *bp = ucontext->uc_mcontext.r30;
+  *sp = ucontext->uc_mcontext.r29;
+#  elif defined(__loongarch__)
+  ucontext_t *ucontext = (ucontext_t *)context;
+  *pc = ucontext->uc_mcontext.__pc;
+  *bp = ucontext->uc_mcontext.__gregs[22];
+  *sp = ucontext->uc_mcontext.__gregs[3];
+#  else
+#    error "Unsupported arch"
+#  endif
+}
+
+void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); }
+
+void InitializePlatformEarly() {
+  // Do nothing.
+}
+
+void CheckASLR() {
+#if SANITIZER_NETBSD
+  int mib[3];
+  int paxflags;
+  uptr len = sizeof(paxflags);
+
+  mib[0] = CTL_PROC;
+  mib[1] = internal_getpid();
+  mib[2] = PROC_PID_PAXFLAGS;
+
+  if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
+    Printf("sysctl failed\n");
+    Die();
+  }
+
+  if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_ASLR)) {
+    Printf("This sanitizer is not compatible with enabled ASLR.\n"
+           "To disable ASLR, please run \"paxctl +a %s\" and try again.\n",
+           GetArgv()[0]);
+    Die();
+  }
+#elif SANITIZER_FREEBSD
+  int aslr_status;
+  int r = internal_procctl(P_PID, 0, PROC_ASLR_STATUS, &aslr_status);
+  if (UNLIKELY(r == -1)) {
+    // We're making things less 'dramatic' here since
+    // the cmd is not necessarily guaranteed to be here
+    // just yet regarding FreeBSD release
+    return;
+  }
+  if ((aslr_status & PROC_ASLR_ACTIVE) != 0) {
+    Printf("This sanitizer is not compatible with enabled ASLR "
+           "and binaries compiled with PIE\n");
+    Die();
+  }
+#  elif SANITIZER_PPC64V2
+  // Disable ASLR for Linux PPC64LE.
+  int old_personality = personality(0xffffffff);
+  if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
+    VReport(1,
+            "WARNING: Program is being run with address space layout "
+            "randomization (ASLR) enabled which prevents the thread and "
+            "memory sanitizers from working on powerpc64le.\n"
+            "ASLR will be disabled and the program re-executed.\n");
+    CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
+    ReExec();
+  }
+#  else
+  // Do nothing
+#  endif
+}
+
+void CheckMPROTECT() {
+#if SANITIZER_NETBSD
+  int mib[3];
+  int paxflags;
+  uptr len = sizeof(paxflags);
+
+  mib[0] = CTL_PROC;
+  mib[1] = internal_getpid();
+  mib[2] = PROC_PID_PAXFLAGS;
+
+  if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
+    Printf("sysctl failed\n");
+    Die();
+  }
+
+  if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_MPROTECT)) {
+    Printf("This sanitizer is not compatible with enabled MPROTECT\n");
+    Die();
+  }
+#else
+  // Do nothing
+#endif
+}
+
+void CheckNoDeepBind(const char *filename, int flag) {
+#ifdef RTLD_DEEPBIND
+  if (flag & RTLD_DEEPBIND) {
+    Report(
+        "You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag"
+        " which is incompatible with sanitizer runtime "
+        "(see https://github.com/google/sanitizers/issues/611 for details"
+        "). If you want to run %s library under sanitizers please remove "
+        "RTLD_DEEPBIND from dlopen flags.\n",
+        filename, filename);
+    Die();
+  }
+#endif
+}
+
+uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
+                              uptr *largest_gap_found,
+                              uptr *max_occupied_addr) {
+  UNREACHABLE("FindAvailableMemoryRange is not available");
+  return 0;
+}
+
+bool GetRandom(void *buffer, uptr length, bool blocking) {
+  if (!buffer || !length || length > 256)
+    return false;
+#if SANITIZER_USE_GETENTROPY
+  uptr rnd = getentropy(buffer, length);
+  int rverrno = 0;
+  if (internal_iserror(rnd, &rverrno) && rverrno == EFAULT)
+    return false;
+  else if (rnd == 0)
+    return true;
+#endif // SANITIZER_USE_GETENTROPY
+
+#if SANITIZER_USE_GETRANDOM
+  static atomic_uint8_t skip_getrandom_syscall;
+  if (!atomic_load_relaxed(&skip_getrandom_syscall)) {
+    // Up to 256 bytes, getrandom will not be interrupted.
+    uptr res = internal_syscall(SYSCALL(getrandom), buffer, length,
+                                blocking ? 0 : GRND_NONBLOCK);
+    int rverrno = 0;
+    if (internal_iserror(res, &rverrno) && rverrno == ENOSYS)
+      atomic_store_relaxed(&skip_getrandom_syscall, 1);
+    else if (res == length)
+      return true;
+  }
+#endif // SANITIZER_USE_GETRANDOM
+  // Up to 256 bytes, a read off /dev/urandom will not be interrupted.
+  // blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom.
+  uptr fd = internal_open("/dev/urandom", O_RDONLY);
+  if (internal_iserror(fd))
+    return false;
+  uptr res = internal_read(fd, buffer, length);
+  if (internal_iserror(res))
+    return false;
+  internal_close(fd);
+  return true;
+}
+
+} // namespace __sanitizer
+
+#endif