Adding upstream version 1.16.10.upstream/1.16.10upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1242 insertions, 0 deletions

diff --git a/src/syscall/syscall_linux.go b/src/syscall/syscall_linux.go
new file mode 100644
index 0000000..3041f6f
--- /dev/null
+++ b/src/syscall/syscall_linux.go
@@ -0,0 +1,1242 @@
+// Copyright 2009 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.
+
+// Linux system calls.
+// This file is compiled as ordinary Go code,
+// but it is also input to mksyscall,
+// which parses the //sys lines and generates system call stubs.
+// Note that sometimes we use a lowercase //sys name and
+// wrap it in our own nicer implementation.
+
+package syscall
+
+import "unsafe"
+
+func rawSyscallNoError(trap, a1, a2, a3 uintptr) (r1, r2 uintptr)
+
+/*
+ * Wrapped
+ */
+
+func Access(path string, mode uint32) (err error) {
+	return Faccessat(_AT_FDCWD, path, mode, 0)
+}
+
+func Chmod(path string, mode uint32) (err error) {
+	return Fchmodat(_AT_FDCWD, path, mode, 0)
+}
+
+func Chown(path string, uid int, gid int) (err error) {
+	return Fchownat(_AT_FDCWD, path, uid, gid, 0)
+}
+
+func Creat(path string, mode uint32) (fd int, err error) {
+	return Open(path, O_CREAT|O_WRONLY|O_TRUNC, mode)
+}
+
+func isGroupMember(gid int) bool {
+	groups, err := Getgroups()
+	if err != nil {
+		return false
+	}
+
+	for _, g := range groups {
+		if g == gid {
+			return true
+		}
+	}
+	return false
+}
+
+//sys	faccessat(dirfd int, path string, mode uint32) (err error)
+
+func Faccessat(dirfd int, path string, mode uint32, flags int) (err error) {
+	if flags & ^(_AT_SYMLINK_NOFOLLOW|_AT_EACCESS) != 0 {
+		return EINVAL
+	}
+
+	// The Linux kernel faccessat system call does not take any flags.
+	// The glibc faccessat implements the flags itself; see
+	// https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/faccessat.c;hb=HEAD
+	// Because people naturally expect syscall.Faccessat to act
+	// like C faccessat, we do the same.
+
+	if flags == 0 {
+		return faccessat(dirfd, path, mode)
+	}
+
+	var st Stat_t
+	if err := fstatat(dirfd, path, &st, flags&_AT_SYMLINK_NOFOLLOW); err != nil {
+		return err
+	}
+
+	mode &= 7
+	if mode == 0 {
+		return nil
+	}
+
+	var uid int
+	if flags&_AT_EACCESS != 0 {
+		uid = Geteuid()
+	} else {
+		uid = Getuid()
+	}
+
+	if uid == 0 {
+		if mode&1 == 0 {
+			// Root can read and write any file.
+			return nil
+		}
+		if st.Mode&0111 != 0 {
+			// Root can execute any file that anybody can execute.
+			return nil
+		}
+		return EACCES
+	}
+
+	var fmode uint32
+	if uint32(uid) == st.Uid {
+		fmode = (st.Mode >> 6) & 7
+	} else {
+		var gid int
+		if flags&_AT_EACCESS != 0 {
+			gid = Getegid()
+		} else {
+			gid = Getgid()
+		}
+
+		if uint32(gid) == st.Gid || isGroupMember(gid) {
+			fmode = (st.Mode >> 3) & 7
+		} else {
+			fmode = st.Mode & 7
+		}
+	}
+
+	if fmode&mode == mode {
+		return nil
+	}
+
+	return EACCES
+}
+
+//sys	fchmodat(dirfd int, path string, mode uint32) (err error)
+
+func Fchmodat(dirfd int, path string, mode uint32, flags int) (err error) {
+	// Linux fchmodat doesn't support the flags parameter. Mimick glibc's behavior
+	// and check the flags. Otherwise the mode would be applied to the symlink
+	// destination which is not what the user expects.
+	if flags&^_AT_SYMLINK_NOFOLLOW != 0 {
+		return EINVAL
+	} else if flags&_AT_SYMLINK_NOFOLLOW != 0 {
+		return EOPNOTSUPP
+	}
+	return fchmodat(dirfd, path, mode)
+}
+
+//sys	linkat(olddirfd int, oldpath string, newdirfd int, newpath string, flags int) (err error)
+
+func Link(oldpath string, newpath string) (err error) {
+	return linkat(_AT_FDCWD, oldpath, _AT_FDCWD, newpath, 0)
+}
+
+func Mkdir(path string, mode uint32) (err error) {
+	return Mkdirat(_AT_FDCWD, path, mode)
+}
+
+func Mknod(path string, mode uint32, dev int) (err error) {
+	return Mknodat(_AT_FDCWD, path, mode, dev)
+}
+
+func Open(path string, mode int, perm uint32) (fd int, err error) {
+	return openat(_AT_FDCWD, path, mode|O_LARGEFILE, perm)
+}
+
+//sys	openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)
+
+func Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error) {
+	return openat(dirfd, path, flags|O_LARGEFILE, mode)
+}
+
+//sys	readlinkat(dirfd int, path string, buf []byte) (n int, err error)
+
+func Readlink(path string, buf []byte) (n int, err error) {
+	return readlinkat(_AT_FDCWD, path, buf)
+}
+
+func Rename(oldpath string, newpath string) (err error) {
+	return Renameat(_AT_FDCWD, oldpath, _AT_FDCWD, newpath)
+}
+
+func Rmdir(path string) error {
+	return unlinkat(_AT_FDCWD, path, _AT_REMOVEDIR)
+}
+
+//sys	symlinkat(oldpath string, newdirfd int, newpath string) (err error)
+
+func Symlink(oldpath string, newpath string) (err error) {
+	return symlinkat(oldpath, _AT_FDCWD, newpath)
+}
+
+func Unlink(path string) error {
+	return unlinkat(_AT_FDCWD, path, 0)
+}
+
+//sys	unlinkat(dirfd int, path string, flags int) (err error)
+
+func Unlinkat(dirfd int, path string) error {
+	return unlinkat(dirfd, path, 0)
+}
+
+func Utimes(path string, tv []Timeval) (err error) {
+	if len(tv) != 2 {
+		return EINVAL
+	}
+	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
+}
+
+//sys	utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)
+
+func UtimesNano(path string, ts []Timespec) (err error) {
+	if len(ts) != 2 {
+		return EINVAL
+	}
+	err = utimensat(_AT_FDCWD, path, (*[2]Timespec)(unsafe.Pointer(&ts[0])), 0)
+	if err != ENOSYS {
+		return err
+	}
+	// If the utimensat syscall isn't available (utimensat was added to Linux
+	// in 2.6.22, Released, 8 July 2007) then fall back to utimes
+	var tv [2]Timeval
+	for i := 0; i < 2; i++ {
+		tv[i].Sec = ts[i].Sec
+		tv[i].Usec = ts[i].Nsec / 1000
+	}
+	return utimes(path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
+}
+
+func Futimesat(dirfd int, path string, tv []Timeval) (err error) {
+	if len(tv) != 2 {
+		return EINVAL
+	}
+	return futimesat(dirfd, path, (*[2]Timeval)(unsafe.Pointer(&tv[0])))
+}
+
+func Futimes(fd int, tv []Timeval) (err error) {
+	// Believe it or not, this is the best we can do on Linux
+	// (and is what glibc does).
+	return Utimes("/proc/self/fd/"+itoa(fd), tv)
+}
+
+const ImplementsGetwd = true
+
+//sys	Getcwd(buf []byte) (n int, err error)
+
+func Getwd() (wd string, err error) {
+	var buf [PathMax]byte
+	n, err := Getcwd(buf[0:])
+	if err != nil {
+		return "", err
+	}
+	// Getcwd returns the number of bytes written to buf, including the NUL.
+	if n < 1 || n > len(buf) || buf[n-1] != 0 {
+		return "", EINVAL
+	}
+	return string(buf[0 : n-1]), nil
+}
+
+func Getgroups() (gids []int, err error) {
+	n, err := getgroups(0, nil)
+	if err != nil {
+		return nil, err
+	}
+	if n == 0 {
+		return nil, nil
+	}
+
+	// Sanity check group count. Max is 1<<16 on Linux.
+	if n < 0 || n > 1<<20 {
+		return nil, EINVAL
+	}
+
+	a := make([]_Gid_t, n)
+	n, err = getgroups(n, &a[0])
+	if err != nil {
+		return nil, err
+	}
+	gids = make([]int, n)
+	for i, v := range a[0:n] {
+		gids[i] = int(v)
+	}
+	return
+}
+
+var cgo_libc_setgroups unsafe.Pointer // non-nil if cgo linked.
+
+func Setgroups(gids []int) (err error) {
+	n := uintptr(len(gids))
+	if n == 0 {
+		if cgo_libc_setgroups == nil {
+			if _, _, e1 := AllThreadsSyscall(_SYS_setgroups, 0, 0, 0); e1 != 0 {
+				err = errnoErr(e1)
+			}
+			return
+		}
+		if ret := cgocaller(cgo_libc_setgroups, 0, 0); ret != 0 {
+			err = errnoErr(Errno(ret))
+		}
+		return
+	}
+
+	a := make([]_Gid_t, len(gids))
+	for i, v := range gids {
+		a[i] = _Gid_t(v)
+	}
+	if cgo_libc_setgroups == nil {
+		if _, _, e1 := AllThreadsSyscall(_SYS_setgroups, n, uintptr(unsafe.Pointer(&a[0])), 0); e1 != 0 {
+			err = errnoErr(e1)
+		}
+		return
+	}
+	if ret := cgocaller(cgo_libc_setgroups, n, uintptr(unsafe.Pointer(&a[0]))); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+type WaitStatus uint32
+
+// Wait status is 7 bits at bottom, either 0 (exited),
+// 0x7F (stopped), or a signal number that caused an exit.
+// The 0x80 bit is whether there was a core dump.
+// An extra number (exit code, signal causing a stop)
+// is in the high bits. At least that's the idea.
+// There are various irregularities. For example, the
+// "continued" status is 0xFFFF, distinguishing itself
+// from stopped via the core dump bit.
+
+const (
+	mask    = 0x7F
+	core    = 0x80
+	exited  = 0x00
+	stopped = 0x7F
+	shift   = 8
+)
+
+func (w WaitStatus) Exited() bool { return w&mask == exited }
+
+func (w WaitStatus) Signaled() bool { return w&mask != stopped && w&mask != exited }
+
+func (w WaitStatus) Stopped() bool { return w&0xFF == stopped }
+
+func (w WaitStatus) Continued() bool { return w == 0xFFFF }
+
+func (w WaitStatus) CoreDump() bool { return w.Signaled() && w&core != 0 }
+
+func (w WaitStatus) ExitStatus() int {
+	if !w.Exited() {
+		return -1
+	}
+	return int(w>>shift) & 0xFF
+}
+
+func (w WaitStatus) Signal() Signal {
+	if !w.Signaled() {
+		return -1
+	}
+	return Signal(w & mask)
+}
+
+func (w WaitStatus) StopSignal() Signal {
+	if !w.Stopped() {
+		return -1
+	}
+	return Signal(w>>shift) & 0xFF
+}
+
+func (w WaitStatus) TrapCause() int {
+	if w.StopSignal() != SIGTRAP {
+		return -1
+	}
+	return int(w>>shift) >> 8
+}
+
+//sys	wait4(pid int, wstatus *_C_int, options int, rusage *Rusage) (wpid int, err error)
+
+func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) {
+	var status _C_int
+	wpid, err = wait4(pid, &status, options, rusage)
+	if wstatus != nil {
+		*wstatus = WaitStatus(status)
+	}
+	return
+}
+
+func Mkfifo(path string, mode uint32) (err error) {
+	return Mknod(path, mode|S_IFIFO, 0)
+}
+
+func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
+	if sa.Port < 0 || sa.Port > 0xFFFF {
+		return nil, 0, EINVAL
+	}
+	sa.raw.Family = AF_INET
+	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
+	p[0] = byte(sa.Port >> 8)
+	p[1] = byte(sa.Port)
+	for i := 0; i < len(sa.Addr); i++ {
+		sa.raw.Addr[i] = sa.Addr[i]
+	}
+	return unsafe.Pointer(&sa.raw), SizeofSockaddrInet4, nil
+}
+
+func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, _Socklen, error) {
+	if sa.Port < 0 || sa.Port > 0xFFFF {
+		return nil, 0, EINVAL
+	}
+	sa.raw.Family = AF_INET6
+	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
+	p[0] = byte(sa.Port >> 8)
+	p[1] = byte(sa.Port)
+	sa.raw.Scope_id = sa.ZoneId
+	for i := 0; i < len(sa.Addr); i++ {
+		sa.raw.Addr[i] = sa.Addr[i]
+	}
+	return unsafe.Pointer(&sa.raw), SizeofSockaddrInet6, nil
+}
+
+func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, _Socklen, error) {
+	name := sa.Name
+	n := len(name)
+	if n > len(sa.raw.Path) {
+		return nil, 0, EINVAL
+	}
+	if n == len(sa.raw.Path) && name[0] != '@' {
+		return nil, 0, EINVAL
+	}
+	sa.raw.Family = AF_UNIX
+	for i := 0; i < n; i++ {
+		sa.raw.Path[i] = int8(name[i])
+	}
+	// length is family (uint16), name, NUL.
+	sl := _Socklen(2)
+	if n > 0 {
+		sl += _Socklen(n) + 1
+	}
+	if sa.raw.Path[0] == '@' {
+		sa.raw.Path[0] = 0
+		// Don't count trailing NUL for abstract address.
+		sl--
+	}
+
+	return unsafe.Pointer(&sa.raw), sl, nil
+}
+
+type SockaddrLinklayer struct {
+	Protocol uint16
+	Ifindex  int
+	Hatype   uint16
+	Pkttype  uint8
+	Halen    uint8
+	Addr     [8]byte
+	raw      RawSockaddrLinklayer
+}
+
+func (sa *SockaddrLinklayer) sockaddr() (unsafe.Pointer, _Socklen, error) {
+	if sa.Ifindex < 0 || sa.Ifindex > 0x7fffffff {
+		return nil, 0, EINVAL
+	}
+	sa.raw.Family = AF_PACKET
+	sa.raw.Protocol = sa.Protocol
+	sa.raw.Ifindex = int32(sa.Ifindex)
+	sa.raw.Hatype = sa.Hatype
+	sa.raw.Pkttype = sa.Pkttype
+	sa.raw.Halen = sa.Halen
+	for i := 0; i < len(sa.Addr); i++ {
+		sa.raw.Addr[i] = sa.Addr[i]
+	}
+	return unsafe.Pointer(&sa.raw), SizeofSockaddrLinklayer, nil
+}
+
+type SockaddrNetlink struct {
+	Family uint16
+	Pad    uint16
+	Pid    uint32
+	Groups uint32
+	raw    RawSockaddrNetlink
+}
+
+func (sa *SockaddrNetlink) sockaddr() (unsafe.Pointer, _Socklen, error) {
+	sa.raw.Family = AF_NETLINK
+	sa.raw.Pad = sa.Pad
+	sa.raw.Pid = sa.Pid
+	sa.raw.Groups = sa.Groups
+	return unsafe.Pointer(&sa.raw), SizeofSockaddrNetlink, nil
+}
+
+func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) {
+	switch rsa.Addr.Family {
+	case AF_NETLINK:
+		pp := (*RawSockaddrNetlink)(unsafe.Pointer(rsa))
+		sa := new(SockaddrNetlink)
+		sa.Family = pp.Family
+		sa.Pad = pp.Pad
+		sa.Pid = pp.Pid
+		sa.Groups = pp.Groups
+		return sa, nil
+
+	case AF_PACKET:
+		pp := (*RawSockaddrLinklayer)(unsafe.Pointer(rsa))
+		sa := new(SockaddrLinklayer)
+		sa.Protocol = pp.Protocol
+		sa.Ifindex = int(pp.Ifindex)
+		sa.Hatype = pp.Hatype
+		sa.Pkttype = pp.Pkttype
+		sa.Halen = pp.Halen
+		for i := 0; i < len(sa.Addr); i++ {
+			sa.Addr[i] = pp.Addr[i]
+		}
+		return sa, nil
+
+	case AF_UNIX:
+		pp := (*RawSockaddrUnix)(unsafe.Pointer(rsa))
+		sa := new(SockaddrUnix)
+		if pp.Path[0] == 0 {
+			// "Abstract" Unix domain socket.
+			// Rewrite leading NUL as @ for textual display.
+			// (This is the standard convention.)
+			// Not friendly to overwrite in place,
+			// but the callers below don't care.
+			pp.Path[0] = '@'
+		}
+
+		// Assume path ends at NUL.
+		// This is not technically the Linux semantics for
+		// abstract Unix domain sockets--they are supposed
+		// to be uninterpreted fixed-size binary blobs--but
+		// everyone uses this convention.
+		n := 0
+		for n < len(pp.Path) && pp.Path[n] != 0 {
+			n++
+		}
+		bytes := (*[len(pp.Path)]byte)(unsafe.Pointer(&pp.Path[0]))[0:n]
+		sa.Name = string(bytes)
+		return sa, nil
+
+	case AF_INET:
+		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
+		sa := new(SockaddrInet4)
+		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
+		sa.Port = int(p[0])<<8 + int(p[1])
+		for i := 0; i < len(sa.Addr); i++ {
+			sa.Addr[i] = pp.Addr[i]
+		}
+		return sa, nil
+
+	case AF_INET6:
+		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
+		sa := new(SockaddrInet6)
+		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
+		sa.Port = int(p[0])<<8 + int(p[1])
+		sa.ZoneId = pp.Scope_id
+		for i := 0; i < len(sa.Addr); i++ {
+			sa.Addr[i] = pp.Addr[i]
+		}
+		return sa, nil
+	}
+	return nil, EAFNOSUPPORT
+}
+
+func Accept(fd int) (nfd int, sa Sockaddr, err error) {
+	var rsa RawSockaddrAny
+	var len _Socklen = SizeofSockaddrAny
+	nfd, err = accept(fd, &rsa, &len)
+	if err != nil {
+		return
+	}
+	sa, err = anyToSockaddr(&rsa)
+	if err != nil {
+		Close(nfd)
+		nfd = 0
+	}
+	return
+}
+
+func Accept4(fd int, flags int) (nfd int, sa Sockaddr, err error) {
+	var rsa RawSockaddrAny
+	var len _Socklen = SizeofSockaddrAny
+	nfd, err = accept4(fd, &rsa, &len, flags)
+	if err != nil {
+		return
+	}
+	if len > SizeofSockaddrAny {
+		panic("RawSockaddrAny too small")
+	}
+	sa, err = anyToSockaddr(&rsa)
+	if err != nil {
+		Close(nfd)
+		nfd = 0
+	}
+	return
+}
+
+func Getsockname(fd int) (sa Sockaddr, err error) {
+	var rsa RawSockaddrAny
+	var len _Socklen = SizeofSockaddrAny
+	if err = getsockname(fd, &rsa, &len); err != nil {
+		return
+	}
+	return anyToSockaddr(&rsa)
+}
+
+func GetsockoptInet4Addr(fd, level, opt int) (value [4]byte, err error) {
+	vallen := _Socklen(4)
+	err = getsockopt(fd, level, opt, unsafe.Pointer(&value[0]), &vallen)
+	return value, err
+}
+
+func GetsockoptIPMreq(fd, level, opt int) (*IPMreq, error) {
+	var value IPMreq
+	vallen := _Socklen(SizeofIPMreq)
+	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
+	return &value, err
+}
+
+func GetsockoptIPMreqn(fd, level, opt int) (*IPMreqn, error) {
+	var value IPMreqn
+	vallen := _Socklen(SizeofIPMreqn)
+	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
+	return &value, err
+}
+
+func GetsockoptIPv6Mreq(fd, level, opt int) (*IPv6Mreq, error) {
+	var value IPv6Mreq
+	vallen := _Socklen(SizeofIPv6Mreq)
+	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
+	return &value, err
+}
+
+func GetsockoptIPv6MTUInfo(fd, level, opt int) (*IPv6MTUInfo, error) {
+	var value IPv6MTUInfo
+	vallen := _Socklen(SizeofIPv6MTUInfo)
+	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
+	return &value, err
+}
+
+func GetsockoptICMPv6Filter(fd, level, opt int) (*ICMPv6Filter, error) {
+	var value ICMPv6Filter
+	vallen := _Socklen(SizeofICMPv6Filter)
+	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
+	return &value, err
+}
+
+func GetsockoptUcred(fd, level, opt int) (*Ucred, error) {
+	var value Ucred
+	vallen := _Socklen(SizeofUcred)
+	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)
+	return &value, err
+}
+
+func SetsockoptIPMreqn(fd, level, opt int, mreq *IPMreqn) (err error) {
+	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), unsafe.Sizeof(*mreq))
+}
+
+func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from Sockaddr, err error) {
+	var msg Msghdr
+	var rsa RawSockaddrAny
+	msg.Name = (*byte)(unsafe.Pointer(&rsa))
+	msg.Namelen = uint32(SizeofSockaddrAny)
+	var iov Iovec
+	if len(p) > 0 {
+		iov.Base = &p[0]
+		iov.SetLen(len(p))
+	}
+	var dummy byte
+	if len(oob) > 0 {
+		if len(p) == 0 {
+			var sockType int
+			sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)
+			if err != nil {
+				return
+			}
+			// receive at least one normal byte
+			if sockType != SOCK_DGRAM {
+				iov.Base = &dummy
+				iov.SetLen(1)
+			}
+		}
+		msg.Control = &oob[0]
+		msg.SetControllen(len(oob))
+	}
+	msg.Iov = &iov
+	msg.Iovlen = 1
+	if n, err = recvmsg(fd, &msg, flags); err != nil {
+		return
+	}
+	oobn = int(msg.Controllen)
+	recvflags = int(msg.Flags)
+	// source address is only specified if the socket is unconnected
+	if rsa.Addr.Family != AF_UNSPEC {
+		from, err = anyToSockaddr(&rsa)
+	}
+	return
+}
+
+func Sendmsg(fd int, p, oob []byte, to Sockaddr, flags int) (err error) {
+	_, err = SendmsgN(fd, p, oob, to, flags)
+	return
+}
+
+func SendmsgN(fd int, p, oob []byte, to Sockaddr, flags int) (n int, err error) {
+	var ptr unsafe.Pointer
+	var salen _Socklen
+	if to != nil {
+		var err error
+		ptr, salen, err = to.sockaddr()
+		if err != nil {
+			return 0, err
+		}
+	}
+	var msg Msghdr
+	msg.Name = (*byte)(ptr)
+	msg.Namelen = uint32(salen)
+	var iov Iovec
+	if len(p) > 0 {
+		iov.Base = &p[0]
+		iov.SetLen(len(p))
+	}
+	var dummy byte
+	if len(oob) > 0 {
+		if len(p) == 0 {
+			var sockType int
+			sockType, err = GetsockoptInt(fd, SOL_SOCKET, SO_TYPE)
+			if err != nil {
+				return 0, err
+			}
+			// send at least one normal byte
+			if sockType != SOCK_DGRAM {
+				iov.Base = &dummy
+				iov.SetLen(1)
+			}
+		}
+		msg.Control = &oob[0]
+		msg.SetControllen(len(oob))
+	}
+	msg.Iov = &iov
+	msg.Iovlen = 1
+	if n, err = sendmsg(fd, &msg, flags); err != nil {
+		return 0, err
+	}
+	if len(oob) > 0 && len(p) == 0 {
+		n = 0
+	}
+	return n, nil
+}
+
+// BindToDevice binds the socket associated with fd to device.
+func BindToDevice(fd int, device string) (err error) {
+	return SetsockoptString(fd, SOL_SOCKET, SO_BINDTODEVICE, device)
+}
+
+//sys	ptrace(request int, pid int, addr uintptr, data uintptr) (err error)
+
+func ptracePeek(req int, pid int, addr uintptr, out []byte) (count int, err error) {
+	// The peek requests are machine-size oriented, so we wrap it
+	// to retrieve arbitrary-length data.
+
+	// The ptrace syscall differs from glibc's ptrace.
+	// Peeks returns the word in *data, not as the return value.
+
+	var buf [sizeofPtr]byte
+
+	// Leading edge. PEEKTEXT/PEEKDATA don't require aligned
+	// access (PEEKUSER warns that it might), but if we don't
+	// align our reads, we might straddle an unmapped page
+	// boundary and not get the bytes leading up to the page
+	// boundary.
+	n := 0
+	if addr%sizeofPtr != 0 {
+		err = ptrace(req, pid, addr-addr%sizeofPtr, uintptr(unsafe.Pointer(&buf[0])))
+		if err != nil {
+			return 0, err
+		}
+		n += copy(out, buf[addr%sizeofPtr:])
+		out = out[n:]
+	}
+
+	// Remainder.
+	for len(out) > 0 {
+		// We use an internal buffer to guarantee alignment.
+		// It's not documented if this is necessary, but we're paranoid.
+		err = ptrace(req, pid, addr+uintptr(n), uintptr(unsafe.Pointer(&buf[0])))
+		if err != nil {
+			return n, err
+		}
+		copied := copy(out, buf[0:])
+		n += copied
+		out = out[copied:]
+	}
+
+	return n, nil
+}
+
+func PtracePeekText(pid int, addr uintptr, out []byte) (count int, err error) {
+	return ptracePeek(PTRACE_PEEKTEXT, pid, addr, out)
+}
+
+func PtracePeekData(pid int, addr uintptr, out []byte) (count int, err error) {
+	return ptracePeek(PTRACE_PEEKDATA, pid, addr, out)
+}
+
+func ptracePoke(pokeReq int, peekReq int, pid int, addr uintptr, data []byte) (count int, err error) {
+	// As for ptracePeek, we need to align our accesses to deal
+	// with the possibility of straddling an invalid page.
+
+	// Leading edge.
+	n := 0
+	if addr%sizeofPtr != 0 {
+		var buf [sizeofPtr]byte
+		err = ptrace(peekReq, pid, addr-addr%sizeofPtr, uintptr(unsafe.Pointer(&buf[0])))
+		if err != nil {
+			return 0, err
+		}
+		n += copy(buf[addr%sizeofPtr:], data)
+		word := *((*uintptr)(unsafe.Pointer(&buf[0])))
+		err = ptrace(pokeReq, pid, addr-addr%sizeofPtr, word)
+		if err != nil {
+			return 0, err
+		}
+		data = data[n:]
+	}
+
+	// Interior.
+	for len(data) > sizeofPtr {
+		word := *((*uintptr)(unsafe.Pointer(&data[0])))
+		err = ptrace(pokeReq, pid, addr+uintptr(n), word)
+		if err != nil {
+			return n, err
+		}
+		n += sizeofPtr
+		data = data[sizeofPtr:]
+	}
+
+	// Trailing edge.
+	if len(data) > 0 {
+		var buf [sizeofPtr]byte
+		err = ptrace(peekReq, pid, addr+uintptr(n), uintptr(unsafe.Pointer(&buf[0])))
+		if err != nil {
+			return n, err
+		}
+		copy(buf[0:], data)
+		word := *((*uintptr)(unsafe.Pointer(&buf[0])))
+		err = ptrace(pokeReq, pid, addr+uintptr(n), word)
+		if err != nil {
+			return n, err
+		}
+		n += len(data)
+	}
+
+	return n, nil
+}
+
+func PtracePokeText(pid int, addr uintptr, data []byte) (count int, err error) {
+	return ptracePoke(PTRACE_POKETEXT, PTRACE_PEEKTEXT, pid, addr, data)
+}
+
+func PtracePokeData(pid int, addr uintptr, data []byte) (count int, err error) {
+	return ptracePoke(PTRACE_POKEDATA, PTRACE_PEEKDATA, pid, addr, data)
+}
+
+func PtraceGetRegs(pid int, regsout *PtraceRegs) (err error) {
+	return ptrace(PTRACE_GETREGS, pid, 0, uintptr(unsafe.Pointer(regsout)))
+}
+
+func PtraceSetRegs(pid int, regs *PtraceRegs) (err error) {
+	return ptrace(PTRACE_SETREGS, pid, 0, uintptr(unsafe.Pointer(regs)))
+}
+
+func PtraceSetOptions(pid int, options int) (err error) {
+	return ptrace(PTRACE_SETOPTIONS, pid, 0, uintptr(options))
+}
+
+func PtraceGetEventMsg(pid int) (msg uint, err error) {
+	var data _C_long
+	err = ptrace(PTRACE_GETEVENTMSG, pid, 0, uintptr(unsafe.Pointer(&data)))
+	msg = uint(data)
+	return
+}
+
+func PtraceCont(pid int, signal int) (err error) {
+	return ptrace(PTRACE_CONT, pid, 0, uintptr(signal))
+}
+
+func PtraceSyscall(pid int, signal int) (err error) {
+	return ptrace(PTRACE_SYSCALL, pid, 0, uintptr(signal))
+}
+
+func PtraceSingleStep(pid int) (err error) { return ptrace(PTRACE_SINGLESTEP, pid, 0, 0) }
+
+func PtraceAttach(pid int) (err error) { return ptrace(PTRACE_ATTACH, pid, 0, 0) }
+
+func PtraceDetach(pid int) (err error) { return ptrace(PTRACE_DETACH, pid, 0, 0) }
+
+//sys	reboot(magic1 uint, magic2 uint, cmd int, arg string) (err error)
+
+func Reboot(cmd int) (err error) {
+	return reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, cmd, "")
+}
+
+func ReadDirent(fd int, buf []byte) (n int, err error) {
+	return Getdents(fd, buf)
+}
+
+func direntIno(buf []byte) (uint64, bool) {
+	return readInt(buf, unsafe.Offsetof(Dirent{}.Ino), unsafe.Sizeof(Dirent{}.Ino))
+}
+
+func direntReclen(buf []byte) (uint64, bool) {
+	return readInt(buf, unsafe.Offsetof(Dirent{}.Reclen), unsafe.Sizeof(Dirent{}.Reclen))
+}
+
+func direntNamlen(buf []byte) (uint64, bool) {
+	reclen, ok := direntReclen(buf)
+	if !ok {
+		return 0, false
+	}
+	return reclen - uint64(unsafe.Offsetof(Dirent{}.Name)), true
+}
+
+//sys	mount(source string, target string, fstype string, flags uintptr, data *byte) (err error)
+
+func Mount(source string, target string, fstype string, flags uintptr, data string) (err error) {
+	// Certain file systems get rather angry and EINVAL if you give
+	// them an empty string of data, rather than NULL.
+	if data == "" {
+		return mount(source, target, fstype, flags, nil)
+	}
+	datap, err := BytePtrFromString(data)
+	if err != nil {
+		return err
+	}
+	return mount(source, target, fstype, flags, datap)
+}
+
+// Sendto
+// Recvfrom
+// Socketpair
+
+/*
+ * Direct access
+ */
+//sys	Acct(path string) (err error)
+//sys	Adjtimex(buf *Timex) (state int, err error)
+//sys	Chdir(path string) (err error)
+//sys	Chroot(path string) (err error)
+//sys	Close(fd int) (err error)
+//sys	Dup(oldfd int) (fd int, err error)
+//sys	Dup3(oldfd int, newfd int, flags int) (err error)
+//sysnb	EpollCreate1(flag int) (fd int, err error)
+//sysnb	EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error)
+//sys	Fallocate(fd int, mode uint32, off int64, len int64) (err error)
+//sys	Fchdir(fd int) (err error)
+//sys	Fchmod(fd int, mode uint32) (err error)
+//sys	Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)
+//sys	fcntl(fd int, cmd int, arg int) (val int, err error)
+//sys	Fdatasync(fd int) (err error)
+//sys	Flock(fd int, how int) (err error)
+//sys	Fsync(fd int) (err error)
+//sys	Getdents(fd int, buf []byte) (n int, err error) = SYS_GETDENTS64
+//sysnb	Getpgid(pid int) (pgid int, err error)
+
+func Getpgrp() (pid int) {
+	pid, _ = Getpgid(0)
+	return
+}
+
+//sysnb	Getpid() (pid int)
+//sysnb	Getppid() (ppid int)
+//sys	Getpriority(which int, who int) (prio int, err error)
+//sysnb	Getrusage(who int, rusage *Rusage) (err error)
+//sysnb	Gettid() (tid int)
+//sys	Getxattr(path string, attr string, dest []byte) (sz int, err error)
+//sys	InotifyAddWatch(fd int, pathname string, mask uint32) (watchdesc int, err error)
+//sysnb	InotifyInit1(flags int) (fd int, err error)
+//sysnb	InotifyRmWatch(fd int, watchdesc uint32) (success int, err error)
+//sysnb	Kill(pid int, sig Signal) (err error)
+//sys	Klogctl(typ int, buf []byte) (n int, err error) = SYS_SYSLOG
+//sys	Listxattr(path string, dest []byte) (sz int, err error)
+//sys	Mkdirat(dirfd int, path string, mode uint32) (err error)
+//sys	Mknodat(dirfd int, path string, mode uint32, dev int) (err error)
+//sys	Nanosleep(time *Timespec, leftover *Timespec) (err error)
+//sys	PivotRoot(newroot string, putold string) (err error) = SYS_PIVOT_ROOT
+//sysnb prlimit(pid int, resource int, newlimit *Rlimit, old *Rlimit) (err error) = SYS_PRLIMIT64
+//sys	read(fd int, p []byte) (n int, err error)
+//sys	Removexattr(path string, attr string) (err error)
+//sys	Setdomainname(p []byte) (err error)
+//sys	Sethostname(p []byte) (err error)
+//sysnb	Setpgid(pid int, pgid int) (err error)
+//sysnb	Setsid() (pid int, err error)
+//sysnb	Settimeofday(tv *Timeval) (err error)
+
+// allThreadsCaller holds the input and output state for performing a
+// allThreadsSyscall that needs to synchronize all OS thread state. Linux
+// generally does not always support this natively, so we have to
+// manipulate the runtime to fix things up.
+type allThreadsCaller struct {
+	// arguments
+	trap, a1, a2, a3, a4, a5, a6 uintptr
+
+	// return values (only set by 0th invocation)
+	r1, r2 uintptr
+
+	// err is the error code
+	err Errno
+}
+
+// doSyscall is a callback for executing a syscall on the current m
+// (OS thread).
+//go:nosplit
+//go:norace
+func (pc *allThreadsCaller) doSyscall(initial bool) bool {
+	r1, r2, err := RawSyscall(pc.trap, pc.a1, pc.a2, pc.a3)
+	if initial {
+		pc.r1 = r1
+		pc.r2 = r2
+		pc.err = err
+	} else if pc.r1 != r1 || (archHonorsR2 && pc.r2 != r2) || pc.err != err {
+		print("trap:", pc.trap, ", a123=[", pc.a1, ",", pc.a2, ",", pc.a3, "]\n")
+		print("results: got {r1=", r1, ",r2=", r2, ",err=", err, "}, want {r1=", pc.r1, ",r2=", pc.r2, ",r3=", pc.err, "}\n")
+		panic("AllThreadsSyscall results differ between threads; runtime corrupted")
+	}
+	return err == 0
+}
+
+// doSyscall6 is a callback for executing a syscall6 on the current m
+// (OS thread).
+//go:nosplit
+//go:norace
+func (pc *allThreadsCaller) doSyscall6(initial bool) bool {
+	r1, r2, err := RawSyscall6(pc.trap, pc.a1, pc.a2, pc.a3, pc.a4, pc.a5, pc.a6)
+	if initial {
+		pc.r1 = r1
+		pc.r2 = r2
+		pc.err = err
+	} else if pc.r1 != r1 || (archHonorsR2 && pc.r2 != r2) || pc.err != err {
+		print("trap:", pc.trap, ", a123456=[", pc.a1, ",", pc.a2, ",", pc.a3, ",", pc.a4, ",", pc.a5, ",", pc.a6, "]\n")
+		print("results: got {r1=", r1, ",r2=", r2, ",err=", err, "}, want {r1=", pc.r1, ",r2=", pc.r2, ",r3=", pc.err, "}\n")
+		panic("AllThreadsSyscall6 results differ between threads; runtime corrupted")
+	}
+	return err == 0
+}
+
+// Provided by runtime.syscall_runtime_doAllThreadsSyscall which
+// serializes the world and invokes the fn on each OS thread (what the
+// runtime refers to as m's). Once this function returns, all threads
+// are in sync.
+func runtime_doAllThreadsSyscall(fn func(bool) bool)
+
+// AllThreadsSyscall performs a syscall on each OS thread of the Go
+// runtime. It first invokes the syscall on one thread. Should that
+// invocation fail, it returns immediately with the error status.
+// Otherwise, it invokes the syscall on all of the remaining threads
+// in parallel. It will terminate the program if it observes any
+// invoked syscall's return value differs from that of the first
+// invocation.
+//
+// AllThreadsSyscall is intended for emulating simultaneous
+// process-wide state changes that require consistently modifying
+// per-thread state of the Go runtime.
+//
+// AllThreadsSyscall is unaware of any threads that are launched
+// explicitly by cgo linked code, so the function always returns
+// ENOTSUP in binaries that use cgo.
+//go:uintptrescapes
+func AllThreadsSyscall(trap, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) {
+	if cgo_libc_setegid != nil {
+		return minus1, minus1, ENOTSUP
+	}
+	pc := &allThreadsCaller{
+		trap: trap,
+		a1:   a1,
+		a2:   a2,
+		a3:   a3,
+	}
+	runtime_doAllThreadsSyscall(pc.doSyscall)
+	r1 = pc.r1
+	r2 = pc.r2
+	err = pc.err
+	return
+}
+
+// AllThreadsSyscall6 is like AllThreadsSyscall, but extended to six
+// arguments.
+//go:uintptrescapes
+func AllThreadsSyscall6(trap, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno) {
+	if cgo_libc_setegid != nil {
+		return minus1, minus1, ENOTSUP
+	}
+	pc := &allThreadsCaller{
+		trap: trap,
+		a1:   a1,
+		a2:   a2,
+		a3:   a3,
+		a4:   a4,
+		a5:   a5,
+		a6:   a6,
+	}
+	runtime_doAllThreadsSyscall(pc.doSyscall6)
+	r1 = pc.r1
+	r2 = pc.r2
+	err = pc.err
+	return
+}
+
+// linked by runtime.cgocall.go
+//go:uintptrescapes
+func cgocaller(unsafe.Pointer, ...uintptr) uintptr
+
+var cgo_libc_setegid unsafe.Pointer // non-nil if cgo linked.
+
+const minus1 = ^uintptr(0)
+
+func Setegid(egid int) (err error) {
+	if cgo_libc_setegid == nil {
+		if _, _, e1 := AllThreadsSyscall(SYS_SETRESGID, minus1, uintptr(egid), minus1); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setegid, uintptr(egid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_seteuid unsafe.Pointer // non-nil if cgo linked.
+
+func Seteuid(euid int) (err error) {
+	if cgo_libc_seteuid == nil {
+		if _, _, e1 := AllThreadsSyscall(SYS_SETRESUID, minus1, uintptr(euid), minus1); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_seteuid, uintptr(euid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_setgid unsafe.Pointer // non-nil if cgo linked.
+
+func Setgid(gid int) (err error) {
+	if cgo_libc_setgid == nil {
+		if _, _, e1 := AllThreadsSyscall(sys_SETGID, uintptr(gid), 0, 0); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setgid, uintptr(gid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_setregid unsafe.Pointer // non-nil if cgo linked.
+
+func Setregid(rgid, egid int) (err error) {
+	if cgo_libc_setregid == nil {
+		if _, _, e1 := AllThreadsSyscall(sys_SETREGID, uintptr(rgid), uintptr(egid), 0); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setregid, uintptr(rgid), uintptr(egid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_setresgid unsafe.Pointer // non-nil if cgo linked.
+
+func Setresgid(rgid, egid, sgid int) (err error) {
+	if cgo_libc_setresgid == nil {
+		if _, _, e1 := AllThreadsSyscall(sys_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid)); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setresgid, uintptr(rgid), uintptr(egid), uintptr(sgid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_setresuid unsafe.Pointer // non-nil if cgo linked.
+
+func Setresuid(ruid, euid, suid int) (err error) {
+	if cgo_libc_setresuid == nil {
+		if _, _, e1 := AllThreadsSyscall(sys_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid)); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setresuid, uintptr(ruid), uintptr(euid), uintptr(suid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_setreuid unsafe.Pointer // non-nil if cgo linked.
+
+func Setreuid(ruid, euid int) (err error) {
+	if cgo_libc_setreuid == nil {
+		if _, _, e1 := AllThreadsSyscall(sys_SETREUID, uintptr(ruid), uintptr(euid), 0); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setreuid, uintptr(ruid), uintptr(euid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+var cgo_libc_setuid unsafe.Pointer // non-nil if cgo linked.
+
+func Setuid(uid int) (err error) {
+	if cgo_libc_setuid == nil {
+		if _, _, e1 := AllThreadsSyscall(sys_SETUID, uintptr(uid), 0, 0); e1 != 0 {
+			err = errnoErr(e1)
+		}
+	} else if ret := cgocaller(cgo_libc_setuid, uintptr(uid)); ret != 0 {
+		err = errnoErr(Errno(ret))
+	}
+	return
+}
+
+//sys	Setpriority(which int, who int, prio int) (err error)
+//sys	Setxattr(path string, attr string, data []byte, flags int) (err error)
+//sys	Sync()
+//sysnb	Sysinfo(info *Sysinfo_t) (err error)
+//sys	Tee(rfd int, wfd int, len int, flags int) (n int64, err error)
+//sysnb	Tgkill(tgid int, tid int, sig Signal) (err error)
+//sysnb	Times(tms *Tms) (ticks uintptr, err error)
+//sysnb	Umask(mask int) (oldmask int)
+//sysnb	Uname(buf *Utsname) (err error)
+//sys	Unmount(target string, flags int) (err error) = SYS_UMOUNT2
+//sys	Unshare(flags int) (err error)
+//sys	write(fd int, p []byte) (n int, err error)
+//sys	exitThread(code int) (err error) = SYS_EXIT
+//sys	readlen(fd int, p *byte, np int) (n int, err error) = SYS_READ
+//sys	writelen(fd int, p *byte, np int) (n int, err error) = SYS_WRITE
+
+// 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 Munmap(b []byte) (err error) {
+	return mapper.Munmap(b)
+}
+
+//sys	Madvise(b []byte, advice int) (err error)
+//sys	Mprotect(b []byte, prot int) (err error)
+//sys	Mlock(b []byte) (err error)
+//sys	Munlock(b []byte) (err error)
+//sys	Mlockall(flags int) (err error)
+//sys	Munlockall() (err error)