syscall_aix.go raw

   1  // Copyright 2018 The Go Authors. All rights reserved.
   2  // Use of this source code is governed by a BSD-style
   3  // license that can be found in the LICENSE file.
   4  
   5  //go:build aix
   6  
   7  // Aix system calls.
   8  // This file is compiled as ordinary Go code,
   9  // but it is also input to mksyscall,
  10  // which parses the //sys lines and generates system call stubs.
  11  // Note that sometimes we use a lowercase //sys name and
  12  // wrap it in our own nicer implementation.
  13  
  14  package unix
  15  
  16  import "unsafe"
  17  
  18  /*
  19   * Wrapped
  20   */
  21  
  22  func Access(path string, mode uint32) (err error) {
  23  	return Faccessat(AT_FDCWD, path, mode, 0)
  24  }
  25  
  26  func Chmod(path string, mode uint32) (err error) {
  27  	return Fchmodat(AT_FDCWD, path, mode, 0)
  28  }
  29  
  30  func Chown(path string, uid int, gid int) (err error) {
  31  	return Fchownat(AT_FDCWD, path, uid, gid, 0)
  32  }
  33  
  34  func Creat(path string, mode uint32) (fd int, err error) {
  35  	return Open(path, O_CREAT|O_WRONLY|O_TRUNC, mode)
  36  }
  37  
  38  //sys	utimes(path string, times *[2]Timeval) (err error)
  39  
  40  func Utimes(path string, tv []Timeval) error {
  41  	if len(tv) != 2 {
  42  		return EINVAL
  43  	}
  44  	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
  45  }
  46  
  47  //sys	utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
  48  
  49  func UtimesNano(path string, ts []Timespec) error {
  50  	if len(ts) != 2 {
  51  		return EINVAL
  52  	}
  53  	return utimensat(AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
  54  }
  55  
  56  func UtimesNanoAt(dirfd int, path string, ts []Timespec, flags int) error {
  57  	if ts == nil {
  58  		return utimensat(dirfd, path, nil, flags)
  59  	}
  60  	if len(ts) != 2 {
  61  		return EINVAL
  62  	}
  63  	return utimensat(dirfd, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), flags)
  64  }
  65  
  66  func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
  67  	if sa.Port < 0 || sa.Port > 0xFFFF {
  68  		return nil, 0, EINVAL
  69  	}
  70  	sa.raw.Family = AF_INET
  71  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
  72  	p[0] = byte(sa.Port >> 8)
  73  	p[1] = byte(sa.Port)
  74  	sa.raw.Addr = sa.Addr
  75  	return unsafe.Pointer(&sa.raw), SizeofSockaddrInet4, nil
  76  }
  77  
  78  func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, _Socklen, error) {
  79  	if sa.Port < 0 || sa.Port > 0xFFFF {
  80  		return nil, 0, EINVAL
  81  	}
  82  	sa.raw.Family = AF_INET6
  83  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
  84  	p[0] = byte(sa.Port >> 8)
  85  	p[1] = byte(sa.Port)
  86  	sa.raw.Scope_id = sa.ZoneId
  87  	sa.raw.Addr = sa.Addr
  88  	return unsafe.Pointer(&sa.raw), SizeofSockaddrInet6, nil
  89  }
  90  
  91  func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, _Socklen, error) {
  92  	name := sa.Name
  93  	n := len(name)
  94  	if n > len(sa.raw.Path) {
  95  		return nil, 0, EINVAL
  96  	}
  97  	if n == len(sa.raw.Path) && name[0] != '@' {
  98  		return nil, 0, EINVAL
  99  	}
 100  	sa.raw.Family = AF_UNIX
 101  	for i := 0; i < n; i++ {
 102  		sa.raw.Path[i] = uint8(name[i])
 103  	}
 104  	// length is family (uint16), name, NUL.
 105  	sl := _Socklen(2)
 106  	if n > 0 {
 107  		sl += _Socklen(n) + 1
 108  	}
 109  	if sa.raw.Path[0] == '@' || (sa.raw.Path[0] == 0 && sl > 3) {
 110  		// Check sl > 3 so we don't change unnamed socket behavior.
 111  		sa.raw.Path[0] = 0
 112  		// Don't count trailing NUL for abstract address.
 113  		sl--
 114  	}
 115  
 116  	return unsafe.Pointer(&sa.raw), sl, nil
 117  }
 118  
 119  func Getsockname(fd int) (sa Sockaddr, err error) {
 120  	var rsa RawSockaddrAny
 121  	var len _Socklen = SizeofSockaddrAny
 122  	if err = getsockname(fd, &rsa, &len); err != nil {
 123  		return
 124  	}
 125  	return anyToSockaddr(fd, &rsa)
 126  }
 127  
 128  //sys	getcwd(buf []byte) (err error)
 129  
 130  const ImplementsGetwd = true
 131  
 132  func Getwd() (ret string, err error) {
 133  	for len := uint64(4096); ; len *= 2 {
 134  		b := make([]byte, len)
 135  		err := getcwd(b)
 136  		if err == nil {
 137  			i := 0
 138  			for b[i] != 0 {
 139  				i++
 140  			}
 141  			return string(b[0:i]), nil
 142  		}
 143  		if err != ERANGE {
 144  			return "", err
 145  		}
 146  	}
 147  }
 148  
 149  func Getcwd(buf []byte) (n int, err error) {
 150  	err = getcwd(buf)
 151  	if err == nil {
 152  		i := 0
 153  		for buf[i] != 0 {
 154  			i++
 155  		}
 156  		n = i + 1
 157  	}
 158  	return
 159  }
 160  
 161  func Getgroups() (gids []int, err error) {
 162  	n, err := getgroups(0, nil)
 163  	if err != nil {
 164  		return nil, err
 165  	}
 166  	if n == 0 {
 167  		return nil, nil
 168  	}
 169  
 170  	// Sanity check group count. Max is 16 on BSD.
 171  	if n < 0 || n > 1000 {
 172  		return nil, EINVAL
 173  	}
 174  
 175  	a := make([]_Gid_t, n)
 176  	n, err = getgroups(n, &a[0])
 177  	if err != nil {
 178  		return nil, err
 179  	}
 180  	gids = make([]int, n)
 181  	for i, v := range a[0:n] {
 182  		gids[i] = int(v)
 183  	}
 184  	return
 185  }
 186  
 187  func Setgroups(gids []int) (err error) {
 188  	if len(gids) == 0 {
 189  		return setgroups(0, nil)
 190  	}
 191  
 192  	a := make([]_Gid_t, len(gids))
 193  	for i, v := range gids {
 194  		a[i] = _Gid_t(v)
 195  	}
 196  	return setgroups(len(a), &a[0])
 197  }
 198  
 199  /*
 200   * Socket
 201   */
 202  
 203  //sys	accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error)
 204  
 205  func Accept(fd int) (nfd int, sa Sockaddr, err error) {
 206  	var rsa RawSockaddrAny
 207  	var len _Socklen = SizeofSockaddrAny
 208  	nfd, err = accept(fd, &rsa, &len)
 209  	if nfd == -1 {
 210  		return
 211  	}
 212  	sa, err = anyToSockaddr(fd, &rsa)
 213  	if err != nil {
 214  		Close(nfd)
 215  		nfd = 0
 216  	}
 217  	return
 218  }
 219  
 220  func recvmsgRaw(fd int, iov []Iovec, oob []byte, flags int, rsa *RawSockaddrAny) (n, oobn int, recvflags int, err error) {
 221  	var msg Msghdr
 222  	msg.Name = (*byte)(unsafe.Pointer(rsa))
 223  	msg.Namelen = uint32(SizeofSockaddrAny)
 224  	var dummy byte
 225  	if len(oob) > 0 {
 226  		// receive at least one normal byte
 227  		if emptyIovecs(iov) {
 228  			var iova [1]Iovec
 229  			iova[0].Base = &dummy
 230  			iova[0].SetLen(1)
 231  			iov = iova[:]
 232  		}
 233  		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
 234  		msg.SetControllen(len(oob))
 235  	}
 236  	if len(iov) > 0 {
 237  		msg.Iov = &iov[0]
 238  		msg.SetIovlen(len(iov))
 239  	}
 240  	if n, err = recvmsg(fd, &msg, flags); n == -1 {
 241  		return
 242  	}
 243  	oobn = int(msg.Controllen)
 244  	recvflags = int(msg.Flags)
 245  	return
 246  }
 247  
 248  func sendmsgN(fd int, iov []Iovec, oob []byte, ptr unsafe.Pointer, salen _Socklen, flags int) (n int, err error) {
 249  	var msg Msghdr
 250  	msg.Name = (*byte)(unsafe.Pointer(ptr))
 251  	msg.Namelen = uint32(salen)
 252  	var dummy byte
 253  	var empty bool
 254  	if len(oob) > 0 {
 255  		// send at least one normal byte
 256  		empty = emptyIovecs(iov)
 257  		if empty {
 258  			var iova [1]Iovec
 259  			iova[0].Base = &dummy
 260  			iova[0].SetLen(1)
 261  			iov = iova[:]
 262  		}
 263  		msg.Control = (*byte)(unsafe.Pointer(&oob[0]))
 264  		msg.SetControllen(len(oob))
 265  	}
 266  	if len(iov) > 0 {
 267  		msg.Iov = &iov[0]
 268  		msg.SetIovlen(len(iov))
 269  	}
 270  	if n, err = sendmsg(fd, &msg, flags); err != nil {
 271  		return 0, err
 272  	}
 273  	if len(oob) > 0 && empty {
 274  		n = 0
 275  	}
 276  	return n, nil
 277  }
 278  
 279  func anyToSockaddr(fd int, rsa *RawSockaddrAny) (Sockaddr, error) {
 280  	switch rsa.Addr.Family {
 281  
 282  	case AF_UNIX:
 283  		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
 284  		sa := new(SockaddrUnix)
 285  
 286  		// Some versions of AIX have a bug in getsockname (see IV78655).
 287  		// We can't rely on sa.Len being set correctly.
 288  		n := SizeofSockaddrUnix - 3 // subtract leading Family, Len, terminating NUL.
 289  		for i := 0; i < n; i++ {
 290  			if pp.Path[i] == 0 {
 291  				n = i
 292  				break
 293  			}
 294  		}
 295  		sa.Name = string(unsafe.Slice((*byte)(unsafe.Pointer(&pp.Path[0])), n))
 296  		return sa, nil
 297  
 298  	case AF_INET:
 299  		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
 300  		sa := new(SockaddrInet4)
 301  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
 302  		sa.Port = int(p[0])<<8 + int(p[1])
 303  		sa.Addr = pp.Addr
 304  		return sa, nil
 305  
 306  	case AF_INET6:
 307  		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
 308  		sa := new(SockaddrInet6)
 309  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
 310  		sa.Port = int(p[0])<<8 + int(p[1])
 311  		sa.ZoneId = pp.Scope_id
 312  		sa.Addr = pp.Addr
 313  		return sa, nil
 314  	}
 315  	return nil, EAFNOSUPPORT
 316  }
 317  
 318  func Gettimeofday(tv *Timeval) (err error) {
 319  	err = gettimeofday(tv, nil)
 320  	return
 321  }
 322  
 323  func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {
 324  	if raceenabled {
 325  		raceReleaseMerge(unsafe.Pointer(&ioSync))
 326  	}
 327  	return sendfile(outfd, infd, offset, count)
 328  }
 329  
 330  // TODO
 331  func sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {
 332  	return -1, ENOSYS
 333  }
 334  
 335  func direntIno(buf []byte) (uint64, bool) {
 336  	return readInt(buf, unsafe.Offsetof(Dirent{}.Ino), unsafe.Sizeof(Dirent{}.Ino))
 337  }
 338  
 339  func direntReclen(buf []byte) (uint64, bool) {
 340  	return readInt(buf, unsafe.Offsetof(Dirent{}.Reclen), unsafe.Sizeof(Dirent{}.Reclen))
 341  }
 342  
 343  func direntNamlen(buf []byte) (uint64, bool) {
 344  	reclen, ok := direntReclen(buf)
 345  	if !ok {
 346  		return 0, false
 347  	}
 348  	return reclen - uint64(unsafe.Offsetof(Dirent{}.Name)), true
 349  }
 350  
 351  //sys	getdirent(fd int, buf []byte) (n int, err error)
 352  
 353  func Getdents(fd int, buf []byte) (n int, err error) {
 354  	return getdirent(fd, buf)
 355  }
 356  
 357  //sys	wait4(pid Pid_t, status *_C_int, options int, rusage *Rusage) (wpid Pid_t, err error)
 358  
 359  func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) {
 360  	var status _C_int
 361  	var r Pid_t
 362  	err = ERESTART
 363  	// AIX wait4 may return with ERESTART errno, while the process is still
 364  	// active.
 365  	for err == ERESTART {
 366  		r, err = wait4(Pid_t(pid), &status, options, rusage)
 367  	}
 368  	wpid = int(r)
 369  	if wstatus != nil {
 370  		*wstatus = WaitStatus(status)
 371  	}
 372  	return
 373  }
 374  
 375  /*
 376   * Wait
 377   */
 378  
 379  type WaitStatus uint32
 380  
 381  func (w WaitStatus) Stopped() bool { return w&0x40 != 0 }
 382  func (w WaitStatus) StopSignal() Signal {
 383  	if !w.Stopped() {
 384  		return -1
 385  	}
 386  	return Signal(w>>8) & 0xFF
 387  }
 388  
 389  func (w WaitStatus) Exited() bool { return w&0xFF == 0 }
 390  func (w WaitStatus) ExitStatus() int {
 391  	if !w.Exited() {
 392  		return -1
 393  	}
 394  	return int((w >> 8) & 0xFF)
 395  }
 396  
 397  func (w WaitStatus) Signaled() bool { return w&0x40 == 0 && w&0xFF != 0 }
 398  func (w WaitStatus) Signal() Signal {
 399  	if !w.Signaled() {
 400  		return -1
 401  	}
 402  	return Signal(w>>16) & 0xFF
 403  }
 404  
 405  func (w WaitStatus) Continued() bool { return w&0x01000000 != 0 }
 406  
 407  func (w WaitStatus) CoreDump() bool { return w&0x80 == 0x80 }
 408  
 409  func (w WaitStatus) TrapCause() int { return -1 }
 410  
 411  //sys	ioctl(fd int, req int, arg uintptr) (err error)
 412  //sys	ioctlPtr(fd int, req int, arg unsafe.Pointer) (err error) = ioctl
 413  
 414  // fcntl must never be called with cmd=F_DUP2FD because it doesn't work on AIX
 415  // There is no way to create a custom fcntl and to keep //sys fcntl easily,
 416  // Therefore, the programmer must call dup2 instead of fcntl in this case.
 417  
 418  // FcntlInt performs a fcntl syscall on fd with the provided command and argument.
 419  //sys	FcntlInt(fd uintptr, cmd int, arg int) (r int,err error) = fcntl
 420  
 421  // FcntlFlock performs a fcntl syscall for the F_GETLK, F_SETLK or F_SETLKW command.
 422  //sys	FcntlFlock(fd uintptr, cmd int, lk *Flock_t) (err error) = fcntl
 423  
 424  //sys	fcntl(fd int, cmd int, arg int) (val int, err error)
 425  
 426  //sys	fsyncRange(fd int, how int, start int64, length int64) (err error) = fsync_range
 427  
 428  func Fsync(fd int) error {
 429  	return fsyncRange(fd, O_SYNC, 0, 0)
 430  }
 431  
 432  /*
 433   * Direct access
 434   */
 435  
 436  //sys	Acct(path string) (err error)
 437  //sys	Chdir(path string) (err error)
 438  //sys	Chroot(path string) (err error)
 439  //sys	Close(fd int) (err error)
 440  //sys	Dup(oldfd int) (fd int, err error)
 441  //sys	Exit(code int)
 442  //sys	Faccessat(dirfd int, path string, mode uint32, flags int) (err error)
 443  //sys	Fchdir(fd int) (err error)
 444  //sys	Fchmod(fd int, mode uint32) (err error)
 445  //sys	Fchmodat(dirfd int, path string, mode uint32, flags int) (err error)
 446  //sys	Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
 447  //sys	Fdatasync(fd int) (err error)
 448  // readdir_r
 449  //sysnb	Getpgid(pid int) (pgid int, err error)
 450  
 451  //sys	Getpgrp() (pid int)
 452  
 453  //sysnb	Getpid() (pid int)
 454  //sysnb	Getppid() (ppid int)
 455  //sys	Getpriority(which int, who int) (prio int, err error)
 456  //sysnb	Getrusage(who int, rusage *Rusage) (err error)
 457  //sysnb	Getsid(pid int) (sid int, err error)
 458  //sysnb	Kill(pid int, sig Signal) (err error)
 459  //sys	Klogctl(typ int, buf []byte) (n int, err error) = syslog
 460  //sys	Mkdir(dirfd int, path string, mode uint32) (err error)
 461  //sys	Mkdirat(dirfd int, path string, mode uint32) (err error)
 462  //sys	Mkfifo(path string, mode uint32) (err error)
 463  //sys	Mknod(path string, mode uint32, dev int) (err error)
 464  //sys	Mknodat(dirfd int, path string, mode uint32, dev int) (err error)
 465  //sys	Nanosleep(time *Timespec, leftover *Timespec) (err error)
 466  //sys	Open(path string, mode int, perm uint32) (fd int, err error) = open64
 467  //sys	Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)
 468  //sys	read(fd int, p []byte) (n int, err error)
 469  //sys	Readlink(path string, buf []byte) (n int, err error)
 470  //sys	Renameat(olddirfd int, oldpath string, newdirfd int, newpath string) (err error)
 471  //sys	Setdomainname(p []byte) (err error)
 472  //sys	Sethostname(p []byte) (err error)
 473  //sysnb	Setpgid(pid int, pgid int) (err error)
 474  //sysnb	Setsid() (pid int, err error)
 475  //sysnb	Settimeofday(tv *Timeval) (err error)
 476  
 477  //sys	Setuid(uid int) (err error)
 478  //sys	Setgid(uid int) (err error)
 479  
 480  //sys	Setpriority(which int, who int, prio int) (err error)
 481  //sys	Statx(dirfd int, path string, flags int, mask int, stat *Statx_t) (err error)
 482  //sys	Sync()
 483  //sysnb	Times(tms *Tms) (ticks uintptr, err error)
 484  //sysnb	Umask(mask int) (oldmask int)
 485  //sysnb	Uname(buf *Utsname) (err error)
 486  //sys	Unlink(path string) (err error)
 487  //sys	Unlinkat(dirfd int, path string, flags int) (err error)
 488  //sys	Ustat(dev int, ubuf *Ustat_t) (err error)
 489  //sys	write(fd int, p []byte) (n int, err error)
 490  
 491  //sys	Dup2(oldfd int, newfd int) (err error)
 492  //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = posix_fadvise64
 493  //sys	Fchown(fd int, uid int, gid int) (err error)
 494  //sys	fstat(fd int, stat *Stat_t) (err error)
 495  //sys	fstatat(dirfd int, path string, stat *Stat_t, flags int) (err error) = fstatat
 496  //sys	Fstatfs(fd int, buf *Statfs_t) (err error)
 497  //sys	Ftruncate(fd int, length int64) (err error)
 498  //sysnb	Getegid() (egid int)
 499  //sysnb	Geteuid() (euid int)
 500  //sysnb	Getgid() (gid int)
 501  //sysnb	Getuid() (uid int)
 502  //sys	Lchown(path string, uid int, gid int) (err error)
 503  //sys	Listen(s int, n int) (err error)
 504  //sys	lstat(path string, stat *Stat_t) (err error)
 505  //sys	Pause() (err error)
 506  //sys	pread(fd int, p []byte, offset int64) (n int, err error) = pread64
 507  //sys	pwrite(fd int, p []byte, offset int64) (n int, err error) = pwrite64
 508  //sys	Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err error)
 509  //sys	Pselect(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timespec, sigmask *Sigset_t) (n int, err error)
 510  //sysnb	Setregid(rgid int, egid int) (err error)
 511  //sysnb	Setreuid(ruid int, euid int) (err error)
 512  //sys	Shutdown(fd int, how int) (err error)
 513  //sys	Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int64, err error)
 514  //sys	stat(path string, statptr *Stat_t) (err error)
 515  //sys	Statfs(path string, buf *Statfs_t) (err error)
 516  //sys	Truncate(path string, length int64) (err error)
 517  
 518  //sys	bind(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 519  //sys	connect(s int, addr unsafe.Pointer, addrlen _Socklen) (err error)
 520  //sysnb	getgroups(n int, list *_Gid_t) (nn int, err error)
 521  //sysnb	setgroups(n int, list *_Gid_t) (err error)
 522  //sys	getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) (err error)
 523  //sys	setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) (err error)
 524  //sysnb	socket(domain int, typ int, proto int) (fd int, err error)
 525  //sysnb	socketpair(domain int, typ int, proto int, fd *[2]int32) (err error)
 526  //sysnb	getpeername(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
 527  //sysnb	getsockname(fd int, rsa *RawSockaddrAny, addrlen *_Socklen) (err error)
 528  //sys	recvfrom(fd int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (n int, err error)
 529  //sys	sendto(s int, buf []byte, flags int, to unsafe.Pointer, addrlen _Socklen) (err error)
 530  
 531  // In order to use msghdr structure with Control, Controllen, nrecvmsg and nsendmsg must be used.
 532  //sys	recvmsg(s int, msg *Msghdr, flags int) (n int, err error) = nrecvmsg
 533  //sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error) = nsendmsg
 534  
 535  //sys	munmap(addr uintptr, length uintptr) (err error)
 536  //sys	Madvise(b []byte, advice int) (err error)
 537  //sys	Mprotect(b []byte, prot int) (err error)
 538  //sys	Mlock(b []byte) (err error)
 539  //sys	Mlockall(flags int) (err error)
 540  //sys	Msync(b []byte, flags int) (err error)
 541  //sys	Munlock(b []byte) (err error)
 542  //sys	Munlockall() (err error)
 543  
 544  //sysnb	pipe(p *[2]_C_int) (err error)
 545  
 546  func Pipe(p []int) (err error) {
 547  	if len(p) != 2 {
 548  		return EINVAL
 549  	}
 550  	var pp [2]_C_int
 551  	err = pipe(&pp)
 552  	if err == nil {
 553  		p[0] = int(pp[0])
 554  		p[1] = int(pp[1])
 555  	}
 556  	return
 557  }
 558  
 559  //sys	poll(fds *PollFd, nfds int, timeout int) (n int, err error)
 560  
 561  func Poll(fds []PollFd, timeout int) (n int, err error) {
 562  	if len(fds) == 0 {
 563  		return poll(nil, 0, timeout)
 564  	}
 565  	return poll(&fds[0], len(fds), timeout)
 566  }
 567  
 568  //sys	gettimeofday(tv *Timeval, tzp *Timezone) (err error)
 569  //sysnb	Time(t *Time_t) (tt Time_t, err error)
 570  //sys	Utime(path string, buf *Utimbuf) (err error)
 571  
 572  //sys	Getsystemcfg(label int) (n uint64)
 573  
 574  //sys	umount(target string) (err error)
 575  
 576  func Unmount(target string, flags int) (err error) {
 577  	if flags != 0 {
 578  		// AIX doesn't have any flags for umount.
 579  		return ENOSYS
 580  	}
 581  	return umount(target)
 582  }
 583