[op] Replace syscall package usage with golang.org/x/sys/unix in pkg/.

The syscall package has been deprecated in favor of golang.org/x/sys.

Note that syscall is still used in the following places:
- pkg/sentry/socket/hostinet/stack.go: some netlink related functionalities
  are not yet available in golang.org/x/sys.
- syscall.Stat_t is still used in some places because os.FileInfo.Sys() still
  returns it and not unix.Stat_t.

Updates #214

PiperOrigin-RevId: 360701387

4 files changed, 15 insertions, 17 deletions

diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go
index 094d993a8..1508cbdf1 100644
--- a/pkg/sentry/fsimpl/gofer/gofer.go
+++ b/pkg/sentry/fsimpl/gofer/gofer.go
@@ -40,8 +40,8 @@ import (
 	"strconv"
 	"strings"
 	"sync/atomic"
-	"syscall"
 
+	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/log"
@@ -550,10 +550,10 @@ func (fs *filesystem) Release(ctx context.Context) {
 		d.dataMu.Unlock()
 		// Close host FDs if they exist.
 		if d.readFD >= 0 {
-			syscall.Close(int(d.readFD))
+			unix.Close(int(d.readFD))
 		}
 		if d.writeFD >= 0 && d.readFD != d.writeFD {
-			syscall.Close(int(d.writeFD))
+			unix.Close(int(d.writeFD))
 		}
 		d.readFD = -1
 		d.writeFD = -1
@@ -1505,10 +1505,10 @@ func (d *dentry) destroyLocked(ctx context.Context) {
 	d.readFile = p9file{}
 	d.writeFile = p9file{}
 	if d.readFD >= 0 {
-		syscall.Close(int(d.readFD))
+		unix.Close(int(d.readFD))
 	}
 	if d.writeFD >= 0 && d.readFD != d.writeFD {
-		syscall.Close(int(d.writeFD))
+		unix.Close(int(d.writeFD))
 	}
 	d.readFD = -1
 	d.writeFD = -1
@@ -1686,7 +1686,7 @@ func (d *dentry) ensureSharedHandle(ctx context.Context, read, write, trunc bool
 						// may use the old or new file description, but this
 						// doesn't matter since they refer to the same file, and
 						// any racing mappings must be read-only.
-						if err := syscall.Dup3(int(h.fd), int(d.readFD), syscall.O_CLOEXEC); err != nil {
+						if err := unix.Dup3(int(h.fd), int(d.readFD), unix.O_CLOEXEC); err != nil {
 							oldFD := d.readFD
 							d.handleMu.Unlock()
 							ctx.Warningf("gofer.dentry.ensureSharedHandle: failed to dup fd %d to fd %d: %v", h.fd, oldFD, err)
@@ -1772,7 +1772,7 @@ func (d *dentry) ensureSharedHandle(ctx context.Context, read, write, trunc bool
 		d.mapsMu.Unlock()
 	}
 	for _, fd := range fdsToClose {
-		syscall.Close(int(fd))
+		unix.Close(int(fd))
 	}
 
 	return nil
@@ -1808,7 +1808,7 @@ func (d *dentry) syncRemoteFileLocked(ctx context.Context) error {
 	// handles otherwise.
 	if d.writeFD >= 0 {
 		ctx.UninterruptibleSleepStart(false)
-		err := syscall.Fsync(int(d.writeFD))
+		err := unix.Fsync(int(d.writeFD))
 		ctx.UninterruptibleSleepFinish(false)
 		return err
 	}
@@ -1817,7 +1817,7 @@ func (d *dentry) syncRemoteFileLocked(ctx context.Context) error {
 	}
 	if d.readFD >= 0 {
 		ctx.UninterruptibleSleepStart(false)
-		err := syscall.Fsync(int(d.readFD))
+		err := unix.Fsync(int(d.readFD))
 		ctx.UninterruptibleSleepFinish(false)
 		return err
 	}
diff --git a/pkg/sentry/fsimpl/gofer/handle.go b/pkg/sentry/fsimpl/gofer/handle.go
index a9ebe1206..0bc201d1c 100644
--- a/pkg/sentry/fsimpl/gofer/handle.go
+++ b/pkg/sentry/fsimpl/gofer/handle.go
@@ -15,8 +15,7 @@
 package gofer
 
 import (
-	"syscall"
-
+	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/p9"
 	"gvisor.dev/gvisor/pkg/safemem"
@@ -73,7 +72,7 @@ func (h *handle) close(ctx context.Context) {
 	h.file.close(ctx)
 	h.file = p9file{}
 	if h.fd >= 0 {
-		syscall.Close(int(h.fd))
+		unix.Close(int(h.fd))
 		h.fd = -1
 	}
 }
diff --git a/pkg/sentry/fsimpl/gofer/socket.go b/pkg/sentry/fsimpl/gofer/socket.go
index a21199eac..fe15f8583 100644
--- a/pkg/sentry/fsimpl/gofer/socket.go
+++ b/pkg/sentry/fsimpl/gofer/socket.go
@@ -15,8 +15,7 @@
 package gofer
 
 import (
-	"syscall"
-
+	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/log"
@@ -118,7 +117,7 @@ func (e *endpoint) newConnectedEndpoint(ctx context.Context, flags p9.ConnectFla
 		return nil, syserr.ErrConnectionRefused
 	}
 	// Dup the fd so that the new endpoint can manage its lifetime.
-	hostFD, err := syscall.Dup(hostFile.FD())
+	hostFD, err := unix.Dup(hostFile.FD())
 	if err != nil {
 		log.Warningf("Could not dup host socket fd %d: %v", hostFile.FD(), err)
 		return nil, syserr.FromError(err)
diff --git a/pkg/sentry/fsimpl/gofer/special_file.go b/pkg/sentry/fsimpl/gofer/special_file.go
index ae972fcb5..ac3b5b621 100644
--- a/pkg/sentry/fsimpl/gofer/special_file.go
+++ b/pkg/sentry/fsimpl/gofer/special_file.go
@@ -16,8 +16,8 @@ package gofer
 
 import (
 	"sync/atomic"
-	"syscall"
 
+	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/fdnotifier"
@@ -376,7 +376,7 @@ func (fd *specialFileFD) sync(ctx context.Context, forFilesystemSync bool) error
 		// RPC.
 		if fd.handle.fd >= 0 {
 			ctx.UninterruptibleSleepStart(false)
-			err := syscall.Fsync(int(fd.handle.fd))
+			err := unix.Fsync(int(fd.handle.fd))
 			ctx.UninterruptibleSleepFinish(false)
 			return err
 		}