func osStackAlloc(s *mspan) {
	osStackRemap(s, _MAP_STACK)
}

func osStackFree(s *mspan) {
	// Undo MAP_STACK.
	osStackRemap(s, 0)
}

func osStackRemap(s *mspan, flags int32) {
	a, err := mmap(unsafe.Pointer(s.base()), s.npages*pageSize, _PROT_READ|_PROT_WRITE, _MAP_PRIVATE|_MAP_ANON|_MAP_FIXED|flags, -1, 0)
	if err != 0 || uintptr(a) != s.base() {

golang.org/x/telemetry/counter/countertest
golang.org/x/telemetry/internal/config
golang.org/x/telemetry/internal/configstore
golang.org/x/telemetry/internal/counter
golang.org/x/telemetry/internal/crashmonitor
golang.org/x/telemetry/internal/mmap
golang.org/x/telemetry/internal/telemetry
golang.org/x/telemetry/internal/upload
# golang.org/x/term v0.20.0
## explicit; go 1.18
golang.org/x/term
# golang.org/x/text v0.16.0
## explicit; go 1.18

// mmap varies by architecture; see syscall_linux_*.go.
//sys	munmap(addr uintptr, length uintptr) (err error)

var mapper = &mmapper{
	active: make(map[*byte][]byte),
	mmap:   mmap,
	munmap: munmap,
}

func Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
	return mapper.Mmap(fd, offset, length, prot, flags)
}

func GetMmap(c Cache, id ActionID) ([]byte, Entry, error) {
	entry, err := c.Get(id)
	if err != nil {
		return nil, entry, err
	}
	md, err := mmap.Mmap(c.OutputFile(entry.OutputID))
	if err != nil {
		return nil, Entry{}, err
	}
	if int64(len(md.Data)) != entry.Size {
		return nil, Entry{}, &entryNotFoundError{Err: errors.New("file incomplete")}
	}

	// Notes:
	// - this version writes everything little-endian, which means
	//   a call is needed to encode every value (expensive)
	// - we may want to move to a model in which we just blast out
	//   all counters, or possibly mmap the file and do the write
	//   implicitly.
	ctrb := make([]byte, 4)
	wrval := func(val uint32) error {
		var buf []byte
		var towr int
		if cfw.cflavor == coverage.CtrRaw {

	}
	return i
}

// Mmap manager, for use by operating system-specific implementations.

type mmapper struct {
	sync.Mutex
	active map[*byte][]byte // active mappings; key is last byte in mapping
	mmap   func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error)
	munmap func(addr uintptr, length uintptr) error
}

    return;
  }

  struct stat st;
  fstat(fd, &st);
  if (S_ISDIR(st.st_mode)) {
    TF_SetStatus(status, TF_FAILED_PRECONDITION, "path is a directory");
  } else {
    const void* address =
        mmap(nullptr, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
    if (address == MAP_FAILED) {
      TF_SetStatusFromIOError(status, errno, path);
    } else {
      region->plugin_memory_region =

// the same process. Examples of excluded memory sources include: OS
// kernel memory held on behalf of the process, memory allocated by
// C code, and memory mapped by syscall.Mmap (because it is not
// managed by the Go runtime).
//
// More specifically, the following expression accurately reflects
// the value the runtime attempts to maintain as the limit:
//

		o.SetSym(symref)
		o.SetName(rs.Name, w.Writer)
		o.Write(w.Writer)
	})
	// TODO: output in sorted order?
	// Currently tools (cmd/internal/goobj package) doesn't use mmap,
	// and it just read it into a map in memory upfront. If it uses
	// mmap, if the output is sorted, it probably could avoid reading
	// into memory and just do lookups in the mmap'd object file.
}

// return the number of aux symbols s have.

//sys	Unlink(path string) (err error)
//sys	Unmount(path string, flags int) (err error)
//sys	write(fd int, p []byte) (n int, err error)
//sys	writev(fd int, iovecs []Iovec) (cnt uintptr, err error)
//sys   mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error)
//sys   munmap(addr uintptr, length uintptr) (err error)
//sysnb fork() (pid int, err error)