t.Fatalf("syscall.open: %v", err)
	}
	defer syscall.Close(fd)

	buf := bytes.Repeat([]byte{0xCD}, direntBufSize)
	for {
		n, err := syscall.ReadDirent(fd, buf)
		if err == syscall.EINVAL {
			// On linux, 'man getdents64' says that EINVAL indicates “result buffer is too small”.
			// Try a bigger buffer.
			t.Logf("ReadDirent: %v; retrying with larger buffer", err)
			buf = bytes.Repeat([]byte{0xCD}, len(buf)*2)
			continue
		}

// license that can be found in the LICENSE file.

package net

import (
	"errors"
	"io"
	"os"
	"syscall"
)

func (fd *netFD) status(ln int) (string, error) {
	if !fd.ok() {
		return "", syscall.EINVAL
	}

	status, err := os.Open(fd.dir + "/status")
	if err != nil {
		return "", err
	}
	defer status.Close()
	buf := make([]byte, ln)
	n, err := io.ReadFull(status, buf[:])
	if err != nil {

			return 0, false, nil
		case syscall.EXDEV, syscall.EINVAL, syscall.EIO, syscall.EOPNOTSUPP, syscall.EPERM:
			// Prior to Linux 5.3, it was not possible to
			// copy_file_range across file systems. Similarly to
			// the ENOSYS case above, if we see EXDEV, we have
			// not transferred any data, and we can let the caller
			// fall back to generic code.
			//
			// As for EINVAL, that is what we see if, for example,

		max := maxSpliceSize
		if int64(max) > remain {
			max = int(remain)
		}
		inPipe, err = spliceDrain(p.wfd, src, max)
		// The operation is considered handled if splice returns no
		// error, or an error other than EINVAL. An EINVAL means the
		// kernel does not support splice for the socket type of src.
		// The failed syscall does not consume any data so it is safe
		// to fall back to a generic copy.
		//

package net

import "syscall"

// SetKeepAliveConfig configures keep-alive messages sent by the operating system.
func (c *TCPConn) SetKeepAliveConfig(config KeepAliveConfig) error {
	if !c.ok() {
		return syscall.EINVAL
	}

	if err := setKeepAlive(c.fd, config.Enable); err != nil {
		return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}
	if err := setKeepAliveIdle(c.fd, config.Idle); err != nil {

}

// SysvShmDetach unmaps the shared memory slice returned from SysvShmAttach.
//
// It is not safe to use the slice after calling this function.
func SysvShmDetach(data []byte) error {
	if len(data) == 0 {
		return EINVAL
	}

	return shmdt(uintptr(unsafe.Pointer(&data[0])))
}

// SysvShmGet returns the Sysv shared memory identifier associated with key.
// If the IPC_CREAT flag is specified a new segment is created.

	"syscall"
)

// SetKeepAliveConfig configures keep-alive messages sent by the operating system.
func (c *TCPConn) SetKeepAliveConfig(config KeepAliveConfig) error {
	if !c.ok() {
		return syscall.EINVAL
	}

	if err := setKeepAlive(c.fd, config.Enable); err != nil {
		return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}

	"syscall"
)

// SetKeepAliveConfig configures keep-alive messages sent by the operating system.
func (c *TCPConn) SetKeepAliveConfig(config KeepAliveConfig) error {
	if !c.ok() {
		return syscall.EINVAL
	}

	if err := setKeepAlive(c.fd, config.Enable); err != nil {
		return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}
	if unix.SupportTCPKeepAliveIdleIntvlCNT() {

	s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_STREAM|syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC, 0)
	if err == nil {
		syscall.Close(s)
	}
	wantSock := err != syscall.EPROTONOSUPPORT && err != syscall.EINVAL
	gotSock := unix.SupportSockNonblockCloexec()
	if wantSock != gotSock {
		t.Fatalf("SupportSockNonblockCloexec, got %t; want %t", gotSock, wantSock)
	}

	// Test that SupportAccept4 returns true if accept4 is available.

	// being used is extremely unlikely.
	pid := math.MaxInt32
	if runtime.GOOS == "solaris" || runtime.GOOS == "illumos" {
		// Solaris/Illumos have a lower limit, above which wait returns
		// EINVAL (see waitid in usr/src/uts/common/os/exit.c in
		// illumos). This is configurable via sysconf(_SC_MAXPID), but
		// we'll just take the default.
		pid = 30000-1
	}

	p, err := FindProcess(pid)
	if err != nil {