From a9441aea2780da8c93da1c73da860219f98438de Mon Sep 17 00:00:00 2001
From: Ayush Ranjan <ayushranjan@google.com>
Date: Wed, 3 Mar 2021 10:23:55 -0800
Subject: [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
---
 pkg/sentry/pgalloc/BUILD             |  1 +
 pkg/sentry/pgalloc/pgalloc.go        | 30 +++++++++++++++---------------
 pkg/sentry/pgalloc/pgalloc_unsafe.go |  7 ++++---
 pkg/sentry/pgalloc/save_restore.go   |  4 ++--
 4 files changed, 22 insertions(+), 20 deletions(-)

(limited to 'pkg/sentry/pgalloc')

diff --git a/pkg/sentry/pgalloc/BUILD b/pkg/sentry/pgalloc/BUILD
index 5b09b9feb..e5bf13c40 100644
--- a/pkg/sentry/pgalloc/BUILD
+++ b/pkg/sentry/pgalloc/BUILD
@@ -97,6 +97,7 @@ go_library(
         "//pkg/sync",
         "//pkg/syserror",
         "//pkg/usermem",
+        "@org_golang_x_sys//unix:go_default_library",
     ],
 )
 
diff --git a/pkg/sentry/pgalloc/pgalloc.go b/pkg/sentry/pgalloc/pgalloc.go
index d99be7f46..58cc11a13 100644
--- a/pkg/sentry/pgalloc/pgalloc.go
+++ b/pkg/sentry/pgalloc/pgalloc.go
@@ -26,9 +26,9 @@ import (
 	"math"
 	"os"
 	"sync/atomic"
-	"syscall"
 	"time"
 
+	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/log"
@@ -341,12 +341,12 @@ func NewMemoryFile(file *os.File, opts MemoryFileOpts) (*MemoryFile, error) {
 	// Work around IMA by immediately creating a temporary PROT_EXEC mapping,
 	// while the backing file is still small. IMA will ignore any future
 	// mappings.
-	m, _, errno := syscall.Syscall6(
-		syscall.SYS_MMAP,
+	m, _, errno := unix.Syscall6(
+		unix.SYS_MMAP,
 		0,
 		usermem.PageSize,
-		syscall.PROT_EXEC,
-		syscall.MAP_SHARED,
+		unix.PROT_EXEC,
+		unix.MAP_SHARED,
 		file.Fd(),
 		0)
 	if errno != 0 {
@@ -354,8 +354,8 @@ func NewMemoryFile(file *os.File, opts MemoryFileOpts) (*MemoryFile, error) {
 		// don't return it.
 		log.Warningf("Failed to pre-map MemoryFile PROT_EXEC: %v", errno)
 	} else {
-		if _, _, errno := syscall.Syscall(
-			syscall.SYS_MUNMAP,
+		if _, _, errno := unix.Syscall(
+			unix.SYS_MUNMAP,
 			m,
 			usermem.PageSize,
 			0); errno != 0 {
@@ -584,7 +584,7 @@ func (f *MemoryFile) decommitFile(fr memmap.FileRange) error {
 	// "After a successful call, subsequent reads from this range will
 	// return zeroes. The FALLOC_FL_PUNCH_HOLE flag must be ORed with
 	// FALLOC_FL_KEEP_SIZE in mode ..." - fallocate(2)
-	return syscall.Fallocate(
+	return unix.Fallocate(
 		int(f.file.Fd()),
 		_FALLOC_FL_PUNCH_HOLE|_FALLOC_FL_KEEP_SIZE,
 		int64(fr.Start),
@@ -730,12 +730,12 @@ func (f *MemoryFile) getChunkMapping(chunk int) ([]uintptr, uintptr, error) {
 	if m := mappings[chunk]; m != 0 {
 		return mappings, m, nil
 	}
-	m, _, errno := syscall.Syscall6(
-		syscall.SYS_MMAP,
+	m, _, errno := unix.Syscall6(
+		unix.SYS_MMAP,
 		0,
 		chunkSize,
-		syscall.PROT_READ|syscall.PROT_WRITE,
-		syscall.MAP_SHARED,
+		unix.PROT_READ|unix.PROT_WRITE,
+		unix.MAP_SHARED,
 		f.file.Fd(),
 		uintptr(chunk<<chunkShift))
 	if errno != 0 {
@@ -1012,8 +1012,8 @@ func (f *MemoryFile) TotalUsage() (uint64, error) {
 	// Stat the underlying file to discover the underlying usage. stat(2)
 	// always reports the allocated block count in units of 512 bytes. This
 	// includes pages in the page cache and swapped pages.
-	var stat syscall.Stat_t
-	if err := syscall.Fstat(int(f.file.Fd()), &stat); err != nil {
+	var stat unix.Stat_t
+	if err := unix.Fstat(int(f.file.Fd()), &stat); err != nil {
 		return 0, err
 	}
 	return uint64(stat.Blocks * 512), nil
@@ -1093,7 +1093,7 @@ func (f *MemoryFile) runReclaim() {
 	mappings := f.mappings.Load().([]uintptr)
 	for i, m := range mappings {
 		if m != 0 {
-			_, _, errno := syscall.Syscall(syscall.SYS_MUNMAP, m, chunkSize, 0)
+			_, _, errno := unix.Syscall(unix.SYS_MUNMAP, m, chunkSize, 0)
 			if errno != 0 {
 				log.Warningf("Failed to unmap mapping %#x for MemoryFile chunk %d: %v", m, i, errno)
 			}
diff --git a/pkg/sentry/pgalloc/pgalloc_unsafe.go b/pkg/sentry/pgalloc/pgalloc_unsafe.go
index a4b5d581c..71f8f66c1 100644
--- a/pkg/sentry/pgalloc/pgalloc_unsafe.go
+++ b/pkg/sentry/pgalloc/pgalloc_unsafe.go
@@ -16,8 +16,9 @@ package pgalloc
 
 import (
 	"reflect"
-	"syscall"
 	"unsafe"
+
+	"golang.org/x/sys/unix"
 )
 
 func unsafeSlice(addr uintptr, length int) (slice []byte) {
@@ -29,8 +30,8 @@ func unsafeSlice(addr uintptr, length int) (slice []byte) {
 }
 
 func mincore(s []byte, buf []byte) error {
-	if _, _, errno := syscall.RawSyscall(
-		syscall.SYS_MINCORE,
+	if _, _, errno := unix.RawSyscall(
+		unix.SYS_MINCORE,
 		uintptr(unsafe.Pointer(&s[0])),
 		uintptr(len(s)),
 		uintptr(unsafe.Pointer(&buf[0]))); errno != 0 {
diff --git a/pkg/sentry/pgalloc/save_restore.go b/pkg/sentry/pgalloc/save_restore.go
index 78317fa35..e05c8d074 100644
--- a/pkg/sentry/pgalloc/save_restore.go
+++ b/pkg/sentry/pgalloc/save_restore.go
@@ -21,8 +21,8 @@ import (
 	"io"
 	"runtime"
 	"sync/atomic"
-	"syscall"
 
+	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
 	"gvisor.dev/gvisor/pkg/state"
@@ -66,7 +66,7 @@ func (f *MemoryFile) SaveTo(ctx context.Context, w wire.Writer) error {
 			// associated backing store. This is equivalent to punching a hole
 			// in the corresponding byte range of the backing store (see
 			// fallocate(2))." - madvise(2)
-			if err := syscall.Madvise(pg, syscall.MADV_REMOVE); err != nil {
+			if err := unix.Madvise(pg, unix.MADV_REMOVE); err != nil {
 				// This doesn't impact the correctness of saved memory, it
 				// just means that we're incrementally more likely to OOM.
 				// Complain, but don't abort saving.
-- 
cgit v1.2.3