text: // Copyright 2016 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  // +build s390x,linux
  
  package unix
  
  import (
  	"unsafe"
  )
  
  //sys	Dup2(oldfd int, newfd int) (err error)
  //sysnb	EpollCreate(size int) (fd int, err error)
  //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
  //sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_FADVISE64
  //sys	Fchown(fd int, uid int, gid int) (err error)
  //sys	Fstat(fd int, stat *Stat_t) (err error)
  //sys	Fstatat(dirfd int, path string, stat *Stat_t, flags int) (err error) = SYS_NEWFSTATAT
  //sys	Fstatfs(fd int, buf *Statfs_t) (err error)
  //sys	Ftruncate(fd int, length int64) (err error)
  //sysnb	Getegid() (egid int)
  //sysnb	Geteuid() (euid int)
  //sysnb	Getgid() (gid int)
  //sysnb	Getrlimit(resource int, rlim *Rlimit) (err error)
  //sysnb	Getuid() (uid int)
  //sysnb	InotifyInit() (fd int, err error)
  //sys	Lchown(path string, uid int, gid int) (err error)
  //sys	Lstat(path string, stat *Stat_t) (err error)
  //sys	Pause() (err error)
  //sys	Pread(fd int, p []byte, offset int64) (n int, err error) = SYS_PREAD64
  //sys	Pwrite(fd int, p []byte, offset int64) (n int, err error) = SYS_PWRITE64
  //sys	Renameat(olddirfd int, oldpath string, newdirfd int, newpath string) (err error)
  //sys	Seek(fd int, offset int64, whence int) (off int64, err error) = SYS_LSEEK
  //sys	Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err error)
  //sys	sendfile(outfd int, infd int, offset *int64, count int) (written int, err error)
  //sys	Setfsgid(gid int) (err error)
  //sys	Setfsuid(uid int) (err error)
  //sysnb	Setregid(rgid int, egid int) (err error)
  //sysnb	Setresgid(rgid int, egid int, sgid int) (err error)
  //sysnb	Setresuid(ruid int, euid int, suid int) (err error)
  //sysnb	Setrlimit(resource int, rlim *Rlimit) (err error)
  //sysnb	Setreuid(ruid int, euid int) (err error)
  //sys	Splice(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int64, err error)
  //sys	Stat(path string, stat *Stat_t) (err error)
  //sys	Statfs(path string, buf *Statfs_t) (err error)
  //sys	SyncFileRange(fd int, off int64, n int64, flags int) (err error)
  //sys	Truncate(path string, length int64) (err error)
  //sys	Ustat(dev int, ubuf *Ustat_t) (err error)
  //sysnb	getgroups(n int, list *_Gid_t) (nn int, err error)
  //sysnb	setgroups(n int, list *_Gid_t) (err error)
  
  //sys	futimesat(dirfd int, path string, times *[2]Timeval) (err error)
  //sysnb	Gettimeofday(tv *Timeval) (err error)
  
  func Time(t *Time_t) (tt Time_t, err error) {
  	var tv Timeval
  	err = Gettimeofday(&tv)
  	if err != nil {
  		return 0, err
  	}
  	if t != nil {
  		*t = Time_t(tv.Sec)
  	}
  	return Time_t(tv.Sec), nil
  }
  
  //sys	Utime(path string, buf *Utimbuf) (err error)
  //sys	utimes(path string, times *[2]Timeval) (err error)
  
  func setTimespec(sec, nsec int64) Timespec {
  	return Timespec{Sec: sec, Nsec: nsec}
  }
  
  func setTimeval(sec, usec int64) Timeval {
  	return Timeval{Sec: sec, Usec: usec}
  }
  
  //sysnb pipe2(p *[2]_C_int, flags int) (err error)
  
  func Pipe(p []int) (err error) {
  	if len(p) != 2 {
  		return EINVAL
  	}
  	var pp [2]_C_int
  	err = pipe2(&pp, 0) // pipe2 is the same as pipe when flags are set to 0.
  	p[0] = int(pp[0])
  	p[1] = int(pp[1])
  	return
  }
  
  func Pipe2(p []int, flags int) (err error) {
  	if len(p) != 2 {
  		return EINVAL
  	}
  	var pp [2]_C_int
  	err = pipe2(&pp, flags)
  	p[0] = int(pp[0])
  	p[1] = int(pp[1])
  	return
  }
  
  func Ioperm(from int, num int, on int) (err error) {
  	return ENOSYS
  }
  
  func Iopl(level int) (err error) {
  	return ENOSYS
  }
  
  func (r *PtraceRegs) PC() uint64 { return r.Psw.Addr }
  
  func (r *PtraceRegs) SetPC(pc uint64) { r.Psw.Addr = pc }
  
  func (iov *Iovec) SetLen(length int) {
  	iov.Len = uint64(length)
  }
  
  func (msghdr *Msghdr) SetControllen(length int) {
  	msghdr.Controllen = uint64(length)
  }
  
  func (cmsg *Cmsghdr) SetLen(length int) {
  	cmsg.Len = uint64(length)
  }
  
  // Linux on s390x uses the old mmap interface, which requires arguments to be passed in a struct.
  // mmap2 also requires arguments to be passed in a struct; it is currently not exposed in <asm/unistd.h>.
  func mmap(addr uintptr, length uintptr, prot int, flags int, fd int, offset int64) (xaddr uintptr, err error) {
  	mmap_args := [6]uintptr{addr, length, uintptr(prot), uintptr(flags), uintptr(fd), uintptr(offset)}
  	r0, _, e1 := Syscall(SYS_MMAP, uintptr(unsafe.Pointer(&mmap_args[0])), 0, 0)
  	xaddr = uintptr(r0)
  	if e1 != 0 {
  		err = errnoErr(e1)
  	}
  	return
  }
  
  // On s390x Linux, all the socket calls go through an extra indirection.
  // The arguments to the underlying system call (SYS_SOCKETCALL) are the
  // number below and a pointer to an array of uintptr.
  const (
  	// see linux/net.h
  	netSocket      = 1
  	netBind        = 2
  	netConnect     = 3
  	netListen      = 4
  	netAccept      = 5
  	netGetSockName = 6
  	netGetPeerName = 7
  	netSocketPair  = 8
  	netSend        = 9
  	netRecv        = 10
  	netSendTo      = 11
  	netRecvFrom    = 12
  	netShutdown    = 13
  	netSetSockOpt  = 14
  	netGetSockOpt  = 15
  	netSendMsg     = 16
  	netRecvMsg     = 17
  	netAccept4     = 18
  	netRecvMMsg    = 19
  	netSendMMsg    = 20
  )
  
  func accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (int, error) {
  	args := [3]uintptr{uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen))}
  	fd, _, err := Syscall(SYS_SOCKETCALL, netAccept, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return 0, err
  	}
  	return int(fd), nil
  }
  
  func accept4(s int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (int, error) {
  	args := [4]uintptr{uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen)), uintptr(flags)}
  	fd, _, err := Syscall(SYS_SOCKETCALL, netAccept4, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return 0, err
  	}
  	return int(fd), nil
  }
  
  func getsockname(s int, rsa *RawSockaddrAny, addrlen *_Socklen) error {
  	args := [3]uintptr{uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen))}
  	_, _, err := RawSyscall(SYS_SOCKETCALL, netGetSockName, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return err
  	}
  	return nil
  }
  
  func getpeername(s int, rsa *RawSockaddrAny, addrlen *_Socklen) error {
  	args := [3]uintptr{uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen))}
  	_, _, err := RawSyscall(SYS_SOCKETCALL, netGetPeerName, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return err
  	}
  	return nil
  }
  
  func socketpair(domain int, typ int, flags int, fd *[2]int32) error {
  	args := [4]uintptr{uintptr(domain), uintptr(typ), uintptr(flags), uintptr(unsafe.Pointer(fd))}
  	_, _, err := RawSyscall(SYS_SOCKETCALL, netSocketPair, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return err
  	}
  	return nil
  }
  
  func bind(s int, addr unsafe.Pointer, addrlen _Socklen) error {
  	args := [3]uintptr{uintptr(s), uintptr(addr), uintptr(addrlen)}
  	_, _, err := Syscall(SYS_SOCKETCALL, netBind, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return err
  	}
  	return nil
  }
  
  func connect(s int, addr unsafe.Pointer, addrlen _Socklen) error {
  	args := [3]uintptr{uintptr(s), uintptr(addr), uintptr(addrlen)}
  	_, _, err := Syscall(SYS_SOCKETCALL, netConnect, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return err
  	}
  	return nil
  }
  
  func socket(domain int, typ int, proto int) (int, error) {
  	args := [3]uintptr{uintptr(domain), uintptr(typ), uintptr(proto)}
  	fd, _, err := RawSyscall(SYS_SOCKETCALL, netSocket, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return 0, err
  	}
  	return int(fd), nil
  }
  
  func getsockopt(s int, level int, name int, val unsafe.Pointer, vallen *_Socklen) error {
  	args := [5]uintptr{uintptr(s), uintptr(level), uintptr(name), uintptr(val), uintptr(unsafe.Pointer(vallen))}
  	_, _, err := Syscall(SYS_SOCKETCALL, netGetSockOpt, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return err
  	}
  	return nil
  }
  
  func setsockopt(s int, level int, name int, val unsafe.Pointer, vallen uintptr) error {
  	args := [4]uintptr{uintptr(s), uintptr(level), uintptr(name), uintptr(val)}
  	_, _, err := Syscall(SYS_SOCKETCALL, netSetSockOpt, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return err
  	}
  	return nil
  }
  
  func recvfrom(s int, p []byte, flags int, from *RawSockaddrAny, fromlen *_Socklen) (int, error) {
  	var base uintptr
  	if len(p) > 0 {
  		base = uintptr(unsafe.Pointer(&p[0]))
  	}
  	args := [6]uintptr{uintptr(s), base, uintptr(len(p)), uintptr(flags), uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(fromlen))}
  	n, _, err := Syscall(SYS_SOCKETCALL, netRecvFrom, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return 0, err
  	}
  	return int(n), nil
  }
  
  func sendto(s int, p []byte, flags int, to unsafe.Pointer, addrlen _Socklen) error {
  	var base uintptr
  	if len(p) > 0 {
  		base = uintptr(unsafe.Pointer(&p[0]))
  	}
  	args := [6]uintptr{uintptr(s), base, uintptr(len(p)), uintptr(flags), uintptr(to), uintptr(addrlen)}
  	_, _, err := Syscall(SYS_SOCKETCALL, netSendTo, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return err
  	}
  	return nil
  }
  
  func recvmsg(s int, msg *Msghdr, flags int) (int, error) {
  	args := [3]uintptr{uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags)}
  	n, _, err := Syscall(SYS_SOCKETCALL, netRecvMsg, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return 0, err
  	}
  	return int(n), nil
  }
  
  func sendmsg(s int, msg *Msghdr, flags int) (int, error) {
  	args := [3]uintptr{uintptr(s), uintptr(unsafe.Pointer(msg)), uintptr(flags)}
  	n, _, err := Syscall(SYS_SOCKETCALL, netSendMsg, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return 0, err
  	}
  	return int(n), nil
  }
  
  func Listen(s int, n int) error {
  	args := [2]uintptr{uintptr(s), uintptr(n)}
  	_, _, err := Syscall(SYS_SOCKETCALL, netListen, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return err
  	}
  	return nil
  }
  
  func Shutdown(s, how int) error {
  	args := [2]uintptr{uintptr(s), uintptr(how)}
  	_, _, err := Syscall(SYS_SOCKETCALL, netShutdown, uintptr(unsafe.Pointer(&args)), 0)
  	if err != 0 {
  		return err
  	}
  	return nil
  }
  
  //sys	poll(fds *PollFd, nfds int, timeout int) (n int, err error)
  
  func Poll(fds []PollFd, timeout int) (n int, err error) {
  	if len(fds) == 0 {
  		return poll(nil, 0, timeout)
  	}
  	return poll(&fds[0], len(fds), timeout)
  }
  
  //sys	kexecFileLoad(kernelFd int, initrdFd int, cmdlineLen int, cmdline string, flags int) (err error)
  
  func KexecFileLoad(kernelFd int, initrdFd int, cmdline string, flags int) error {
  	cmdlineLen := len(cmdline)
  	if cmdlineLen > 0 {
  		// Account for the additional NULL byte added by
  		// BytePtrFromString in kexecFileLoad. The kexec_file_load
  		// syscall expects a NULL-terminated string.
  		cmdlineLen++
  	}
  	return kexecFileLoad(kernelFd, initrdFd, cmdlineLen, cmdline, flags)
  }
  