niki/vendor/golang.org/x/sys/unix/syscall_darwin.go

// Copyright 2009,2010 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.

// Darwin 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, either here or in

// syscall_bsd.go or syscall_unix.go.

package unix

import (
	"fmt"
	"syscall"
	"unsafe"
)

//sys	closedir(dir uintptr) (err error)

//sys	readdir_r(dir uintptr, entry *Dirent, result **Dirent) (res Errno)

func fdopendir(fd int) (dir uintptr, err error) {

	r0, _, e1 := syscall_syscallPtr(libc_fdopendir_trampoline_addr, uintptr(fd), 0, 0)

	dir = uintptr(r0)

	if e1 != 0 {

		err = errnoErr(e1)

	}

	return

}

var libc_fdopendir_trampoline_addr uintptr

//go:cgo_import_dynamic libc_fdopendir fdopendir "/usr/lib/libSystem.B.dylib"

func Getdirentries(fd int, buf []byte, basep *uintptr) (n int, err error) {

	// Simulate Getdirentries using fdopendir/readdir_r/closedir.

	// We store the number of entries to skip in the seek

	// offset of fd. See issue #31368.

	// It's not the full required semantics, but should handle the case

	// of calling Getdirentries or ReadDirent repeatedly.

	// It won't handle assigning the results of lseek to *basep, or handle

	// the directory being edited underfoot.

	skip, err := Seek(fd, 0, 1 /* SEEK_CUR */)

	if err != nil {

		return 0, err

	}

	// We need to duplicate the incoming file descriptor

	// because the caller expects to retain control of it, but

	// fdopendir expects to take control of its argument.

	// Just Dup'ing the file descriptor is not enough, as the

	// result shares underlying state. Use Openat to make a really

	// new file descriptor referring to the same directory.

	fd2, err := Openat(fd, ".", O_RDONLY, 0)

	if err != nil {

		return 0, err

	}

	d, err := fdopendir(fd2)

	if err != nil {

		Close(fd2)

		return 0, err

	}

	defer closedir(d)

	var cnt int64

	for {

		var entry Dirent

		var entryp *Dirent

		e := readdir_r(d, &entry, &entryp)

		if e != 0 {

			return n, errnoErr(e)

		}

		if entryp == nil {

			break

		}

		if skip > 0 {

			skip--

			cnt++

			continue

		}

		reclen := int(entry.Reclen)

		if reclen > len(buf) {

			// Not enough room. Return for now.

			// The counter will let us know where we should start up again.

			// Note: this strategy for suspending in the middle and

			// restarting is O(n^2) in the length of the directory. Oh well.

			break

		}

		// Copy entry into return buffer.

		s := unsafe.Slice((*byte)(unsafe.Pointer(&entry)), reclen)

		copy(buf, s)

		buf = buf[reclen:]

		n += reclen

		cnt++

	}

	// Set the seek offset of the input fd to record

	// how many files we've already returned.

	_, err = Seek(fd, cnt, 0 /* SEEK_SET */)

	if err != nil {

		return n, err

	}

	return n, nil

}

// SockaddrDatalink implements the Sockaddr interface for AF_LINK type sockets.

type SockaddrDatalink struct {
	Len uint8

	Family uint8

	Index uint16

	Type uint8

	Nlen uint8

	Alen uint8

	Slen uint8

	Data [12]int8

	raw RawSockaddrDatalink
}

// SockaddrCtl implements the Sockaddr interface for AF_SYSTEM type sockets.

type SockaddrCtl struct {
	ID uint32

	Unit uint32

	raw RawSockaddrCtl
}

func (sa *SockaddrCtl) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Sc_len = SizeofSockaddrCtl

	sa.raw.Sc_family = AF_SYSTEM

	sa.raw.Ss_sysaddr = AF_SYS_CONTROL

	sa.raw.Sc_id = sa.ID

	sa.raw.Sc_unit = sa.Unit

	return unsafe.Pointer(&sa.raw), SizeofSockaddrCtl, nil

}

// SockaddrVM implements the Sockaddr interface for AF_VSOCK type sockets.

// SockaddrVM provides access to Darwin VM sockets: a mechanism that enables

// bidirectional communication between a hypervisor and its guest virtual

// machines.

type SockaddrVM struct {

	// CID and Port specify a context ID and port address for a VM socket.

	// Guests have a unique CID, and hosts may have a well-known CID of:

	//  - VMADDR_CID_HYPERVISOR: refers to the hypervisor process.

	//  - VMADDR_CID_LOCAL: refers to local communication (loopback).

	//  - VMADDR_CID_HOST: refers to other processes on the host.

	CID uint32

	Port uint32

	raw RawSockaddrVM
}

func (sa *SockaddrVM) sockaddr() (unsafe.Pointer, _Socklen, error) {

	sa.raw.Len = SizeofSockaddrVM

	sa.raw.Family = AF_VSOCK

	sa.raw.Port = sa.Port

	sa.raw.Cid = sa.CID

	return unsafe.Pointer(&sa.raw), SizeofSockaddrVM, nil

}

func anyToSockaddrGOOS(fd int, rsa *RawSockaddrAny) (Sockaddr, error) {

	switch rsa.Addr.Family {

	case AF_SYSTEM:

		pp := (*RawSockaddrCtl)(unsafe.Pointer(rsa))

		if pp.Ss_sysaddr == AF_SYS_CONTROL {

			sa := new(SockaddrCtl)

			sa.ID = pp.Sc_id

			sa.Unit = pp.Sc_unit

			return sa, nil

		}

	case AF_VSOCK:

		pp := (*RawSockaddrVM)(unsafe.Pointer(rsa))

		sa := &SockaddrVM{

			CID: pp.Cid,

			Port: pp.Port,
		}

		return sa, nil

	}

	return nil, EAFNOSUPPORT

}

// Some external packages rely on SYS___SYSCTL being defined to implement their

// own sysctl wrappers. Provide it here, even though direct syscalls are no

// longer supported on darwin.

const SYS___SYSCTL = SYS_SYSCTL

// Translate "kern.hostname" to []_C_int{0,1,2,3}.

func nametomib(name string) (mib []_C_int, err error) {

	const siz = unsafe.Sizeof(mib[0])

	// NOTE(rsc): It seems strange to set the buffer to have

	// size CTL_MAXNAME+2 but use only CTL_MAXNAME

	// as the size. I don't know why the +2 is here, but the

	// kernel uses +2 for its own implementation of this function.

	// I am scared that if we don't include the +2 here, the kernel

	// will silently write 2 words farther than we specify

	// and we'll get memory corruption.

	var buf [CTL_MAXNAME + 2]_C_int

	n := uintptr(CTL_MAXNAME) * siz

	p := (*byte)(unsafe.Pointer(&buf[0]))

	bytes, err := ByteSliceFromString(name)

	if err != nil {

		return nil, err

	}

	// Magic sysctl: "setting" 0.3 to a string name

	// lets you read back the array of integers form.

	if err = sysctl([]_C_int{0, 3}, p, &n, &bytes[0], uintptr(len(name))); err != nil {

		return nil, err

	}

	return buf[0 : n/siz], nil

}

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) {

	return readInt(buf, unsafe.Offsetof(Dirent{}.Namlen), unsafe.Sizeof(Dirent{}.Namlen))

}

func PtraceAttach(pid int) (err error) { return ptrace(PT_ATTACH, pid, 0, 0) }

func PtraceDetach(pid int) (err error) { return ptrace(PT_DETACH, pid, 0, 0) }

func PtraceDenyAttach() (err error) { return ptrace(PT_DENY_ATTACH, 0, 0, 0) }

//sysnb	pipe(p *[2]int32) (err error)

func Pipe(p []int) (err error) {

	if len(p) != 2 {

		return EINVAL

	}

	var x [2]int32

	err = pipe(&x)

	if err == nil {

		p[0] = int(x[0])

		p[1] = int(x[1])

	}

	return

}

func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {

	var _p0 unsafe.Pointer

	var bufsize uintptr

	if len(buf) > 0 {

		_p0 = unsafe.Pointer(&buf[0])

		bufsize = unsafe.Sizeof(Statfs_t{}) * uintptr(len(buf))

	}

	return getfsstat(_p0, bufsize, flags)

}

func xattrPointer(dest []byte) *byte {

	// It's only when dest is set to NULL that the OS X implementations of

	// getxattr() and listxattr() return the current sizes of the named attributes.

	// An empty byte array is not sufficient. To maintain the same behaviour as the

	// linux implementation, we wrap around the system calls and pass in NULL when

	// dest is empty.

	var destp *byte

	if len(dest) > 0 {

		destp = &dest[0]

	}

	return destp

}

//sys	getxattr(path string, attr string, dest *byte, size int, position uint32, options int) (sz int, err error)

func Getxattr(path string, attr string, dest []byte) (sz int, err error) {

	return getxattr(path, attr, xattrPointer(dest), len(dest), 0, 0)

}

func Lgetxattr(link string, attr string, dest []byte) (sz int, err error) {

	return getxattr(link, attr, xattrPointer(dest), len(dest), 0, XATTR_NOFOLLOW)

}

//sys	fgetxattr(fd int, attr string, dest *byte, size int, position uint32, options int) (sz int, err error)

func Fgetxattr(fd int, attr string, dest []byte) (sz int, err error) {

	return fgetxattr(fd, attr, xattrPointer(dest), len(dest), 0, 0)

}

//sys	setxattr(path string, attr string, data *byte, size int, position uint32, options int) (err error)

func Setxattr(path string, attr string, data []byte, flags int) (err error) {

	// The parameters for the OS X implementation vary slightly compared to the

	// linux system call, specifically the position parameter:

	//

	//  linux:

	//      int setxattr(

	//          const char *path,

	//          const char *name,

	//          const void *value,

	//          size_t size,

	//          int flags

	//      );

	//

	//  darwin:

	//      int setxattr(

	//          const char *path,

	//          const char *name,

	//          void *value,

	//          size_t size,

	//          u_int32_t position,

	//          int options

	//      );

	//

	// position specifies the offset within the extended attribute. In the

	// current implementation, only the resource fork extended attribute makes

	// use of this argument. For all others, position is reserved. We simply

	// default to setting it to zero.

	return setxattr(path, attr, xattrPointer(data), len(data), 0, flags)

}

func Lsetxattr(link string, attr string, data []byte, flags int) (err error) {

	return setxattr(link, attr, xattrPointer(data), len(data), 0, flags|XATTR_NOFOLLOW)

}

//sys	fsetxattr(fd int, attr string, data *byte, size int, position uint32, options int) (err error)

func Fsetxattr(fd int, attr string, data []byte, flags int) (err error) {

	return fsetxattr(fd, attr, xattrPointer(data), len(data), 0, 0)

}

//sys	removexattr(path string, attr string, options int) (err error)

func Removexattr(path string, attr string) (err error) {

	// We wrap around and explicitly zero out the options provided to the OS X

	// implementation of removexattr, we do so for interoperability with the

	// linux variant.

	return removexattr(path, attr, 0)

}

func Lremovexattr(link string, attr string) (err error) {

	return removexattr(link, attr, XATTR_NOFOLLOW)

}

//sys	fremovexattr(fd int, attr string, options int) (err error)

func Fremovexattr(fd int, attr string) (err error) {

	return fremovexattr(fd, attr, 0)

}

//sys	listxattr(path string, dest *byte, size int, options int) (sz int, err error)

func Listxattr(path string, dest []byte) (sz int, err error) {

	return listxattr(path, xattrPointer(dest), len(dest), 0)

}

func Llistxattr(link string, dest []byte) (sz int, err error) {

	return listxattr(link, xattrPointer(dest), len(dest), XATTR_NOFOLLOW)

}

//sys	flistxattr(fd int, dest *byte, size int, options int) (sz int, err error)

func Flistxattr(fd int, dest []byte) (sz int, err error) {

	return flistxattr(fd, xattrPointer(dest), len(dest), 0)

}

//sys	utimensat(dirfd int, path string, times *[2]Timespec, flags int) (err error)

/*

 * Wrapped

 */

//sys	fcntl(fd int, cmd int, arg int) (val int, err error)

//sys	kill(pid int, signum int, posix int) (err error)

func Kill(pid int, signum syscall.Signal) (err error) { return kill(pid, int(signum), 1) }

//sys	ioctl(fd int, req uint, arg uintptr) (err error)

//sys	ioctlPtr(fd int, req uint, arg unsafe.Pointer) (err error) = SYS_IOCTL

func IoctlCtlInfo(fd int, ctlInfo *CtlInfo) error {

	return ioctlPtr(fd, CTLIOCGINFO, unsafe.Pointer(ctlInfo))

}

// IfreqMTU is struct ifreq used to get or set a network device's MTU.

type IfreqMTU struct {
	Name [IFNAMSIZ]byte

	MTU int32
}

// IoctlGetIfreqMTU performs the SIOCGIFMTU ioctl operation on fd to get the MTU

// of the network device specified by ifname.

func IoctlGetIfreqMTU(fd int, ifname string) (*IfreqMTU, error) {

	var ifreq IfreqMTU

	copy(ifreq.Name[:], ifname)

	err := ioctlPtr(fd, SIOCGIFMTU, unsafe.Pointer(&ifreq))

	return &ifreq, err

}

// IoctlSetIfreqMTU performs the SIOCSIFMTU ioctl operation on fd to set the MTU

// of the network device specified by ifreq.Name.

func IoctlSetIfreqMTU(fd int, ifreq *IfreqMTU) error {

	return ioctlPtr(fd, SIOCSIFMTU, unsafe.Pointer(ifreq))

}

//sys	sysctl(mib []_C_int, old *byte, oldlen *uintptr, new *byte, newlen uintptr) (err error) = SYS_SYSCTL

func Uname(uname *Utsname) error {

	mib := []_C_int{CTL_KERN, KERN_OSTYPE}

	n := unsafe.Sizeof(uname.Sysname)

	if err := sysctl(mib, &uname.Sysname[0], &n, nil, 0); err != nil {

		return err

	}

	mib = []_C_int{CTL_KERN, KERN_HOSTNAME}

	n = unsafe.Sizeof(uname.Nodename)

	if err := sysctl(mib, &uname.Nodename[0], &n, nil, 0); err != nil {

		return err

	}

	mib = []_C_int{CTL_KERN, KERN_OSRELEASE}

	n = unsafe.Sizeof(uname.Release)

	if err := sysctl(mib, &uname.Release[0], &n, nil, 0); err != nil {

		return err

	}

	mib = []_C_int{CTL_KERN, KERN_VERSION}

	n = unsafe.Sizeof(uname.Version)

	if err := sysctl(mib, &uname.Version[0], &n, nil, 0); err != nil {

		return err

	}

	// The version might have newlines or tabs in it, convert them to

	// spaces.

	for i, b := range uname.Version {

		if b == '\n' || b == '\t' {

			if i == len(uname.Version)-1 {

				uname.Version[i] = 0

			} else {

				uname.Version[i] = ' '

			}

		}

	}

	mib = []_C_int{CTL_HW, HW_MACHINE}

	n = unsafe.Sizeof(uname.Machine)

	if err := sysctl(mib, &uname.Machine[0], &n, nil, 0); err != nil {

		return err

	}

	return nil

}

func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {

	if raceenabled {

		raceReleaseMerge(unsafe.Pointer(&ioSync))

	}

	var length = int64(count)

	err = sendfile(infd, outfd, *offset, &length, nil, 0)

	written = int(length)

	return

}

func GetsockoptIPMreqn(fd, level, opt int) (*IPMreqn, error) {

	var value IPMreqn

	vallen := _Socklen(SizeofIPMreqn)

	errno := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)

	return &value, errno

}

func SetsockoptIPMreqn(fd, level, opt int, mreq *IPMreqn) (err error) {

	return setsockopt(fd, level, opt, unsafe.Pointer(mreq), unsafe.Sizeof(*mreq))

}

// GetsockoptXucred is a getsockopt wrapper that returns an Xucred struct.

// The usual level and opt are SOL_LOCAL and LOCAL_PEERCRED, respectively.

func GetsockoptXucred(fd, level, opt int) (*Xucred, error) {

	x := new(Xucred)

	vallen := _Socklen(SizeofXucred)

	err := getsockopt(fd, level, opt, unsafe.Pointer(x), &vallen)

	return x, err

}

func GetsockoptTCPConnectionInfo(fd, level, opt int) (*TCPConnectionInfo, error) {

	var value TCPConnectionInfo

	vallen := _Socklen(SizeofTCPConnectionInfo)

	err := getsockopt(fd, level, opt, unsafe.Pointer(&value), &vallen)

	return &value, err

}

func SysctlKinfoProc(name string, args ...int) (*KinfoProc, error) {

	mib, err := sysctlmib(name, args...)

	if err != nil {

		return nil, err

	}

	var kinfo KinfoProc

	n := uintptr(SizeofKinfoProc)

	if err := sysctl(mib, (*byte)(unsafe.Pointer(&kinfo)), &n, nil, 0); err != nil {

		return nil, err

	}

	if n != SizeofKinfoProc {

		return nil, EIO

	}

	return &kinfo, nil

}

func SysctlKinfoProcSlice(name string, args ...int) ([]KinfoProc, error) {

	mib, err := sysctlmib(name, args...)

	if err != nil {

		return nil, err

	}

	for {

		// Find size.

		n := uintptr(0)

		if err := sysctl(mib, nil, &n, nil, 0); err != nil {

			return nil, err

		}

		if n == 0 {

			return nil, nil

		}

		if n%SizeofKinfoProc != 0 {

			return nil, fmt.Errorf("sysctl() returned a size of %d, which is not a multiple of %d", n, SizeofKinfoProc)

		}

		// Read into buffer of that size.

		buf := make([]KinfoProc, n/SizeofKinfoProc)

		if err := sysctl(mib, (*byte)(unsafe.Pointer(&buf[0])), &n, nil, 0); err != nil {

			if err == ENOMEM {

				// Process table grew. Try again.

				continue

			}

			return nil, err

		}

		if n%SizeofKinfoProc != 0 {

			return nil, fmt.Errorf("sysctl() returned a size of %d, which is not a multiple of %d", n, SizeofKinfoProc)

		}

		// The actual call may return less than the original reported required

		// size so ensure we deal with that.

		return buf[:n/SizeofKinfoProc], nil

	}

}

//sys	sendfile(infd int, outfd int, offset int64, len *int64, hdtr unsafe.Pointer, flags int) (err error)

//sys	shmat(id int, addr uintptr, flag int) (ret uintptr, err error)

//sys	shmctl(id int, cmd int, buf *SysvShmDesc) (result int, err error)

//sys	shmdt(addr uintptr) (err error)

//sys	shmget(key int, size int, flag int) (id int, err error)

/*

 * Exposed directly

 */

//sys	Access(path string, mode uint32) (err error)

//sys	Adjtime(delta *Timeval, olddelta *Timeval) (err error)

//sys	Chdir(path string) (err error)

//sys	Chflags(path string, flags int) (err error)

//sys	Chmod(path string, mode uint32) (err error)

//sys	Chown(path string, uid int, gid int) (err error)

//sys	Chroot(path string) (err error)

//sys	ClockGettime(clockid int32, time *Timespec) (err error)

//sys	Close(fd int) (err error)

//sys	Clonefile(src string, dst string, flags int) (err error)

//sys	Clonefileat(srcDirfd int, src string, dstDirfd int, dst string, flags int) (err error)

//sys	Dup(fd int) (nfd int, err error)

//sys	Dup2(from int, to int) (err error)

//sys	Exchangedata(path1 string, path2 string, options int) (err error)

//sys	Exit(code int)

//sys	Faccessat(dirfd int, path string, mode uint32, flags int) (err error)

//sys	Fchdir(fd int) (err error)

//sys	Fchflags(fd int, flags int) (err error)

//sys	Fchmod(fd int, mode uint32) (err error)

//sys	Fchmodat(dirfd int, path string, mode uint32, flags int) (err error)

//sys	Fchown(fd int, uid int, gid int) (err error)

//sys	Fchownat(dirfd int, path string, uid int, gid int, flags int) (err error)

//sys	Fclonefileat(srcDirfd int, dstDirfd int, dst string, flags int) (err error)

//sys	Flock(fd int, how int) (err error)

//sys	Fpathconf(fd int, name int) (val int, err error)

//sys	Fsync(fd int) (err error)

//sys	Ftruncate(fd int, length int64) (err error)

//sys	Getcwd(buf []byte) (n int, err error)

//sys	Getdtablesize() (size int)

//sysnb	Getegid() (egid int)

//sysnb	Geteuid() (uid int)

//sysnb	Getgid() (gid int)

//sysnb	Getpgid(pid int) (pgid int, err error)

//sysnb	Getpgrp() (pgrp int)

//sysnb	Getpid() (pid int)

//sysnb	Getppid() (ppid int)

//sys	Getpriority(which int, who int) (prio int, err error)

//sysnb	Getrlimit(which int, lim *Rlimit) (err error)

//sysnb	Getrusage(who int, rusage *Rusage) (err error)

//sysnb	Getsid(pid int) (sid int, err error)

//sysnb	Gettimeofday(tp *Timeval) (err error)

//sysnb	Getuid() (uid int)

//sysnb	Issetugid() (tainted bool)

//sys	Kqueue() (fd int, err error)

//sys	Lchown(path string, uid int, gid int) (err error)

//sys	Link(path string, link string) (err error)

//sys	Linkat(pathfd int, path string, linkfd int, link string, flags int) (err error)

//sys	Listen(s int, backlog int) (err error)

//sys	Mkdir(path string, mode uint32) (err error)

//sys	Mkdirat(dirfd int, path string, mode uint32) (err error)

//sys	Mkfifo(path string, mode uint32) (err error)

//sys	Mknod(path string, mode uint32, dev int) (err error)

//sys	Mount(fsType string, dir string, flags int, data unsafe.Pointer) (err error)

//sys	Open(path string, mode int, perm uint32) (fd int, err error)

//sys	Openat(dirfd int, path string, mode int, perm uint32) (fd int, err error)

//sys	Pathconf(path string, name int) (val int, err error)

//sys	pread(fd int, p []byte, offset int64) (n int, err error)

//sys	pwrite(fd int, p []byte, offset int64) (n int, err error)

//sys	read(fd int, p []byte) (n int, err error)

//sys	Readlink(path string, buf []byte) (n int, err error)

//sys	Readlinkat(dirfd int, path string, buf []byte) (n int, err error)

//sys	Rename(from string, to string) (err error)

//sys	Renameat(fromfd int, from string, tofd int, to string) (err error)

//sys	Revoke(path string) (err error)

//sys	Rmdir(path string) (err error)

//sys	Seek(fd int, offset int64, whence int) (newoffset int64, err error) = SYS_LSEEK

//sys	Select(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timeval) (n int, err error)

//sys	Setattrlist(path string, attrlist *Attrlist, attrBuf []byte, options int) (err error)

//sys	Setegid(egid int) (err error)

//sysnb	Seteuid(euid int) (err error)

//sysnb	Setgid(gid int) (err error)

//sys	Setlogin(name string) (err error)

//sysnb	Setpgid(pid int, pgid int) (err error)

//sys	Setpriority(which int, who int, prio int) (err error)

//sys	Setprivexec(flag int) (err error)

//sysnb	Setregid(rgid int, egid int) (err error)

//sysnb	Setreuid(ruid int, euid int) (err error)

//sysnb	Setsid() (pid int, err error)

//sysnb	Settimeofday(tp *Timeval) (err error)

//sysnb	Setuid(uid int) (err error)

//sys	Symlink(path string, link string) (err error)

//sys	Symlinkat(oldpath string, newdirfd int, newpath string) (err error)

//sys	Sync() (err error)

//sys	Truncate(path string, length int64) (err error)

//sys	Umask(newmask int) (oldmask int)

//sys	Undelete(path string) (err error)

//sys	Unlink(path string) (err error)

//sys	Unlinkat(dirfd int, path string, flags int) (err error)

//sys	Unmount(path string, flags int) (err error)

//sys	write(fd int, p []byte) (n int, 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)