[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

6 files changed, 20 insertions, 22 deletions

diff --git a/pkg/flipcall/BUILD b/pkg/flipcall/BUILD
index cc31d0175..9730b88c1 100644
--- a/pkg/flipcall/BUILD
+++ b/pkg/flipcall/BUILD
@@ -20,6 +20,7 @@ go_library(
         "//pkg/log",
         "//pkg/memutil",
         "//pkg/sync",
+        "@org_golang_x_sys//unix:go_default_library",
     ],
 )
 
diff --git a/pkg/flipcall/flipcall.go b/pkg/flipcall/flipcall.go
index c4a3366ce..8d8309a73 100644
--- a/pkg/flipcall/flipcall.go
+++ b/pkg/flipcall/flipcall.go
@@ -20,7 +20,8 @@ import (
 	"fmt"
 	"math"
 	"sync/atomic"
-	"syscall"
+
+	"golang.org/x/sys/unix"
 )
 
 // An Endpoint provides the ability to synchronously transfer data and control
@@ -130,7 +131,7 @@ func (ep *Endpoint) Destroy() {
 }
 
 func (ep *Endpoint) unmapPacket() {
-	syscall.RawSyscall(syscall.SYS_MUNMAP, ep.packet, uintptr(ep.dataCap)+PacketHeaderBytes, 0)
+	unix.RawSyscall(unix.SYS_MUNMAP, ep.packet, uintptr(ep.dataCap)+PacketHeaderBytes, 0)
 	ep.packet = 0
 }
 
diff --git a/pkg/flipcall/futex_linux.go b/pkg/flipcall/futex_linux.go
index 0e559ee16..c212f05f1 100644
--- a/pkg/flipcall/futex_linux.go
+++ b/pkg/flipcall/futex_linux.go
@@ -20,8 +20,8 @@ import (
 	"fmt"
 	"runtime"
 	"sync/atomic"
-	"syscall"
 
+	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/abi/linux"
 )
 
@@ -66,22 +66,22 @@ func (ep *Endpoint) futexWaitUntilActive() error {
 }
 
 func (ep *Endpoint) futexWakeConnState(numThreads int32) error {
-	if _, _, e := syscall.RawSyscall(syscall.SYS_FUTEX, ep.packet, linux.FUTEX_WAKE, uintptr(numThreads)); e != 0 {
+	if _, _, e := unix.RawSyscall(unix.SYS_FUTEX, ep.packet, linux.FUTEX_WAKE, uintptr(numThreads)); e != 0 {
 		return e
 	}
 	return nil
 }
 
 func (ep *Endpoint) futexWaitConnState(curState uint32) error {
-	_, _, e := syscall.Syscall6(syscall.SYS_FUTEX, ep.packet, linux.FUTEX_WAIT, uintptr(curState), 0, 0, 0)
-	if e != 0 && e != syscall.EAGAIN && e != syscall.EINTR {
+	_, _, e := unix.Syscall6(unix.SYS_FUTEX, ep.packet, linux.FUTEX_WAIT, uintptr(curState), 0, 0, 0)
+	if e != 0 && e != unix.EAGAIN && e != unix.EINTR {
 		return e
 	}
 	return nil
 }
 
 func yieldThread() {
-	syscall.Syscall(syscall.SYS_SCHED_YIELD, 0, 0, 0)
+	unix.Syscall(unix.SYS_SCHED_YIELD, 0, 0, 0)
 	// The thread we're trying to yield to may be waiting for a Go runtime P.
 	// runtime.Gosched() will hand off ours if necessary.
 	runtime.Gosched()
diff --git a/pkg/flipcall/packet_window_allocator.go b/pkg/flipcall/packet_window_allocator.go
index af9cc3d21..9122c97b7 100644
--- a/pkg/flipcall/packet_window_allocator.go
+++ b/pkg/flipcall/packet_window_allocator.go
@@ -18,8 +18,8 @@ import (
 	"fmt"
 	"math/bits"
 	"os"
-	"syscall"
 
+	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/memutil"
 )
@@ -85,8 +85,8 @@ func (pwa *PacketWindowAllocator) Init() error {
 	// Apply F_SEAL_SHRINK to prevent either party from causing SIGBUS in the
 	// other by truncating the file, and F_SEAL_SEAL to prevent either party
 	// from applying F_SEAL_GROW or F_SEAL_WRITE.
-	if _, _, e := syscall.RawSyscall(syscall.SYS_FCNTL, uintptr(fd), linux.F_ADD_SEALS, linux.F_SEAL_SHRINK|linux.F_SEAL_SEAL); e != 0 {
-		syscall.Close(fd)
+	if _, _, e := unix.RawSyscall(unix.SYS_FCNTL, uintptr(fd), linux.F_ADD_SEALS, linux.F_SEAL_SHRINK|linux.F_SEAL_SEAL); e != 0 {
+		unix.Close(fd)
 		return fmt.Errorf("failed to apply memfd seals: %v", e)
 	}
 	pwa.fd = fd
@@ -106,7 +106,7 @@ func NewPacketWindowAllocator() (*PacketWindowAllocator, error) {
 // Destroy releases resources owned by pwa. This invalidates file descriptors
 // previously returned by pwa.FD() and pwd.Allocate().
 func (pwa *PacketWindowAllocator) Destroy() {
-	syscall.Close(pwa.fd)
+	unix.Close(pwa.fd)
 }
 
 // FD represents the file descriptor of the shared memory file backing pwa.
@@ -158,7 +158,7 @@ func (pwa *PacketWindowAllocator) ensureFileSize(min int64) error {
 		}
 		newSize = newNewSize
 	}
-	if err := syscall.Ftruncate(pwa.FD(), newSize); err != nil {
+	if err := unix.Ftruncate(pwa.FD(), newSize); err != nil {
 		return fmt.Errorf("ftruncate failed: %v", err)
 	}
 	pwa.fileSize = newSize
diff --git a/pkg/flipcall/packet_window_mmap_amd64.go b/pkg/flipcall/packet_window_mmap_amd64.go
index 869183b11..ced587a2a 100644
--- a/pkg/flipcall/packet_window_mmap_amd64.go
+++ b/pkg/flipcall/packet_window_mmap_amd64.go
@@ -14,12 +14,10 @@
 
 package flipcall
 
-import (
-	"syscall"
-)
+import "golang.org/x/sys/unix"
 
 // Return a memory mapping of the pwd in memory that can be shared outside the sandbox.
-func packetWindowMmap(pwd PacketWindowDescriptor) (uintptr, syscall.Errno) {
-	m, _, err := syscall.RawSyscall6(syscall.SYS_MMAP, 0, uintptr(pwd.Length), syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED, uintptr(pwd.FD), uintptr(pwd.Offset))
+func packetWindowMmap(pwd PacketWindowDescriptor) (uintptr, unix.Errno) {
+	m, _, err := unix.RawSyscall6(unix.SYS_MMAP, 0, uintptr(pwd.Length), unix.PROT_READ|unix.PROT_WRITE, unix.MAP_SHARED, uintptr(pwd.FD), uintptr(pwd.Offset))
 	return m, err
 }
diff --git a/pkg/flipcall/packet_window_mmap_arm64.go b/pkg/flipcall/packet_window_mmap_arm64.go
index b9c9c44f6..87ad1a4a1 100644
--- a/pkg/flipcall/packet_window_mmap_arm64.go
+++ b/pkg/flipcall/packet_window_mmap_arm64.go
@@ -16,12 +16,10 @@
 
 package flipcall
 
-import (
-	"syscall"
-)
+import "golang.org/x/sys/unix"
 
 // Return a memory mapping of the pwd in memory that can be shared outside the sandbox.
-func packetWindowMmap(pwd PacketWindowDescriptor) (uintptr, syscall.Errno) {
-	m, _, err := syscall.RawSyscall6(syscall.SYS_MMAP, 0, uintptr(pwd.Length), syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED, uintptr(pwd.FD), uintptr(pwd.Offset))
+func packetWindowMmap(pwd PacketWindowDescriptor) (uintptr, unix.Errno) {
+	m, _, err := unix.RawSyscall6(unix.SYS_MMAP, 0, uintptr(pwd.Length), unix.PROT_READ|unix.PROT_WRITE, unix.MAP_SHARED, uintptr(pwd.FD), uintptr(pwd.Offset))
 	return m, err
 }