1 files changed, 31 insertions, 9 deletions
diff --git a/pkg/sentry/fs/proc/uptime.go b/pkg/sentry/fs/proc/uptime.go
index 80c7ce0b4..40d0fd1fd 100644
--- a/pkg/sentry/fs/proc/uptime.go
+++ b/pkg/sentry/fs/proc/uptime.go
@@ -18,42 +18,64 @@ import (
 	"fmt"
 	"io"
 
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/context"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
-	"gvisor.googlesource.com/gvisor/pkg/sentry/fs/ramfs"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil"
 	ktime "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/time"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
 	"gvisor.googlesource.com/gvisor/pkg/syserror"
+	"gvisor.googlesource.com/gvisor/pkg/waiter"
 )
 
 // uptime is a file containing the system uptime.
 //
 // +stateify savable
 type uptime struct {
-	ramfs.Entry
+	fsutil.SimpleFileInode
 
 	// The "start time" of the sandbox.
 	startTime ktime.Time
 }
 
 // newUptime returns a new uptime file.
-func (p *proc) newUptime(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
+func newUptime(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
 	u := &uptime{
-		startTime: ktime.NowFromContext(ctx),
+		SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0444), linux.PROC_SUPER_MAGIC),
+		startTime:       ktime.NowFromContext(ctx),
 	}
-	u.InitEntry(ctx, fs.RootOwner, fs.FilePermsFromMode(0444))
-	return newFile(u, msrc, fs.SpecialFile, nil)
+	return newProcInode(u, msrc, fs.SpecialFile, nil)
 }
 
-// DeprecatedPreadv reads the current uptime.
-func (u *uptime) DeprecatedPreadv(ctx context.Context, dst usermem.IOSequence, offset int64) (int64, error) {
+// GetFile implements fs.InodeOperations.GetFile.
+func (u *uptime) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) {
+	return fs.NewFile(ctx, dirent, flags, &uptimeFile{startTime: u.startTime}), nil
+}
+
+// +stateify savable
+type uptimeFile struct {
+	waiter.AlwaysReady       `state:"nosave"`
+	fsutil.FileGenericSeek   `state:"nosave"`
+	fsutil.FileNoIoctl       `state:"nosave"`
+	fsutil.FileNoMMap        `state:"nosave"`
+	fsutil.FileNoopFlush     `state:"nosave"`
+	fsutil.FileNoopFsync     `state:"nosave"`
+	fsutil.FileNoopRelease   `state:"nosave"`
+	fsutil.FileNotDirReaddir `state:"nosave"`
+	fsutil.FileNoWrite       `state:"nosave"`
+
+	startTime ktime.Time
+}
+
+// Read implements fs.FileOperations.Read.
+func (f *uptimeFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, offset int64) (int64, error) {
 	if offset < 0 {
 		return 0, syserror.EINVAL
 	}
 
 	now := ktime.NowFromContext(ctx)
 	// Pretend that we've spent zero time sleeping (second number).
-	s := []byte(fmt.Sprintf("%.2f 0.00\n", now.Sub(u.startTime).Seconds()))
+	s := []byte(fmt.Sprintf("%.2f 0.00\n", now.Sub(f.startTime).Seconds()))
 	if offset >= int64(len(s)) {
 		return 0, io.EOF
 	}