diff --git a/vendor/golang.org/x/sys/unix/syscall_unix.go b/vendor/golang.org/x/sys/unix/syscall_unix.go
index 33583a2..3de3756 100644
--- a/vendor/golang.org/x/sys/unix/syscall_unix.go
+++ b/vendor/golang.org/x/sys/unix/syscall_unix.go
@@ -28,6 +28,11 @@
 	errENOENT error = syscall.ENOENT
 )
 
+var (
+	signalNameMapOnce sync.Once
+	signalNameMap     map[string]syscall.Signal
+)
+
 // errnoErr returns common boxed Errno values, to prevent
 // allocations at runtime.
 func errnoErr(e syscall.Errno) error {
@@ -66,6 +71,19 @@
 	return ""
 }
 
+// SignalNum returns the syscall.Signal for signal named s,
+// or 0 if a signal with such name is not found.
+// The signal name should start with "SIG".
+func SignalNum(s string) syscall.Signal {
+	signalNameMapOnce.Do(func() {
+		signalNameMap = make(map[string]syscall.Signal)
+		for _, signal := range signalList {
+			signalNameMap[signal.name] = signal.num
+		}
+	})
+	return signalNameMap[s]
+}
+
 // clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte.
 func clen(n []byte) int {
 	i := bytes.IndexByte(n, 0)
@@ -276,6 +294,13 @@
 	return &tv, err
 }
 
+func GetsockoptUint64(fd, level, opt int) (value uint64, err error) {
+	var n uint64
+	vallen := _Socklen(8)
+	err = getsockopt(fd, level, opt, unsafe.Pointer(&n), &vallen)
+	return n, err
+}
+
 func Recvfrom(fd int, p []byte, flags int) (n int, from Sockaddr, err error) {
 	var rsa RawSockaddrAny
 	var len _Socklen = SizeofSockaddrAny
@@ -326,13 +351,21 @@
 }
 
 func SetsockoptString(fd, level, opt int, s string) (err error) {
-	return setsockopt(fd, level, opt, unsafe.Pointer(&[]byte(s)[0]), uintptr(len(s)))
+	var p unsafe.Pointer
+	if len(s) > 0 {
+		p = unsafe.Pointer(&[]byte(s)[0])
+	}
+	return setsockopt(fd, level, opt, p, uintptr(len(s)))
 }
 
 func SetsockoptTimeval(fd, level, opt int, tv *Timeval) (err error) {
 	return setsockopt(fd, level, opt, unsafe.Pointer(tv), unsafe.Sizeof(*tv))
 }
 
+func SetsockoptUint64(fd, level, opt int, value uint64) (err error) {
+	return setsockopt(fd, level, opt, unsafe.Pointer(&value), 8)
+}
+
 func Socket(domain, typ, proto int) (fd int, err error) {
 	if domain == AF_INET6 && SocketDisableIPv6 {
 		return -1, EAFNOSUPPORT
@@ -377,3 +410,22 @@
 func Exec(argv0 string, argv []string, envv []string) error {
 	return syscall.Exec(argv0, argv, envv)
 }
+
+// Lutimes sets the access and modification times tv on path. If path refers to
+// a symlink, it is not dereferenced and the timestamps are set on the symlink.
+// If tv is nil, the access and modification times are set to the current time.
+// Otherwise tv must contain exactly 2 elements, with access time as the first
+// element and modification time as the second element.
+func Lutimes(path string, tv []Timeval) error {
+	if tv == nil {
+		return UtimesNanoAt(AT_FDCWD, path, nil, AT_SYMLINK_NOFOLLOW)
+	}
+	if len(tv) != 2 {
+		return EINVAL
+	}
+	ts := []Timespec{
+		NsecToTimespec(TimevalToNsec(tv[0])),
+		NsecToTimespec(TimevalToNsec(tv[1])),
+	}
+	return UtimesNanoAt(AT_FDCWD, path, ts, AT_SYMLINK_NOFOLLOW)
+}