Merge release-20200804.0-52-g3be26a271 (automated)

4 files changed, 36 insertions, 23 deletions

diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go
index 99461368f..cec4abf10 100644
--- a/pkg/abi/linux/linux_abi_autogen_unsafe.go
+++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go
@@ -150,7 +150,7 @@ func (s *Statx) Packed() bool {
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
 func (s *Statx) MarshalUnsafe(dst []byte) {
-    if s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() {
+    if s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() {
         safecopy.CopyIn(dst, unsafe.Pointer(s))
     } else {
         // Type Statx doesn't have a packed layout in memory, fallback to MarshalBytes.
@@ -171,7 +171,7 @@ func (s *Statx) UnmarshalUnsafe(src []byte) {
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
 func (s *Statx) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) {
-    if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() {
+    if !s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() {
         // Type Statx doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
         s.MarshalBytes(buf) // escapes: fallback.
@@ -620,7 +620,7 @@ func (f *FUSEHeaderIn) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (f *FUSEHeaderIn) Packed() bool {
-    return f.Opcode.Packed() && f.Unique.Packed()
+    return f.Unique.Packed() && f.Opcode.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -702,7 +702,7 @@ func (f *FUSEHeaderIn) CopyIn(task marshal.Task, addr usermem.Addr) (int, error)
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (f *FUSEHeaderIn) WriteTo(w io.Writer) (int64, error) {
-    if !f.Opcode.Packed() && f.Unique.Packed() {
+    if !f.Unique.Packed() && f.Opcode.Packed() {
         // Type FUSEHeaderIn doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, f.SizeBytes())
         f.MarshalBytes(buf)
@@ -1630,7 +1630,7 @@ func (i *IPTEntry) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (i *IPTEntry) Packed() bool {
-    return i.Counters.Packed() && i.IP.Packed()
+    return i.IP.Packed() && i.Counters.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -1656,7 +1656,7 @@ func (i *IPTEntry) UnmarshalUnsafe(src []byte) {
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
 func (i *IPTEntry) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) {
-    if !i.Counters.Packed() && i.IP.Packed() {
+    if !i.IP.Packed() && i.Counters.Packed() {
         // Type IPTEntry doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := task.CopyScratchBuffer(i.SizeBytes()) // escapes: okay.
         i.MarshalBytes(buf) // escapes: fallback.
@@ -1712,7 +1712,7 @@ func (i *IPTEntry) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (i *IPTEntry) WriteTo(w io.Writer) (int64, error) {
-    if !i.IP.Packed() && i.Counters.Packed() {
+    if !i.Counters.Packed() && i.IP.Packed() {
         // Type IPTEntry doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, i.SizeBytes())
         i.MarshalBytes(buf)
@@ -1818,12 +1818,12 @@ func (i *IPTIP) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (i *IPTIP) Packed() bool {
-    return i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed()
+    return i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
 func (i *IPTIP) MarshalUnsafe(dst []byte) {
-    if i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() {
+    if i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() {
         safecopy.CopyIn(dst, unsafe.Pointer(i))
     } else {
         // Type IPTIP doesn't have a packed layout in memory, fallback to MarshalBytes.
@@ -1844,7 +1844,7 @@ func (i *IPTIP) UnmarshalUnsafe(src []byte) {
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
 func (i *IPTIP) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) {
-    if !i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() {
+    if !i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() {
         // Type IPTIP doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := task.CopyScratchBuffer(i.SizeBytes()) // escapes: okay.
         i.MarshalBytes(buf) // escapes: fallback.
diff --git a/pkg/sentry/fsimpl/overlay/directory.go b/pkg/sentry/fsimpl/overlay/directory.go
index fccb94105..6a79f7ffe 100644
--- a/pkg/sentry/fsimpl/overlay/directory.go
+++ b/pkg/sentry/fsimpl/overlay/directory.go
@@ -51,7 +51,7 @@ func (d *dentry) collectWhiteoutsForRmdirLocked(ctx context.Context) (map[string
 		// Reuse slice allocated for maybeWhiteouts from a previous layer to
 		// reduce allocations.
 		maybeWhiteouts = maybeWhiteouts[:0]
-		if err := layerFD.IterDirents(ctx, vfs.IterDirentsCallbackFunc(func(dirent vfs.Dirent) error {
+		err = layerFD.IterDirents(ctx, vfs.IterDirentsCallbackFunc(func(dirent vfs.Dirent) error {
 			if dirent.Name == "." || dirent.Name == ".." {
 				return nil
 			}
@@ -68,7 +68,8 @@ func (d *dentry) collectWhiteoutsForRmdirLocked(ctx context.Context) (map[string
 			}
 			// Non-whiteout file in the directory prevents rmdir.
 			return syserror.ENOTEMPTY
-		})); err != nil {
+		}))
+		if err != nil {
 			readdirErr = err
 			return false
 		}
@@ -182,7 +183,7 @@ func (d *dentry) getDirents(ctx context.Context) ([]vfs.Dirent, error) {
 		// Reuse slice allocated for maybeWhiteouts from a previous layer to
 		// reduce allocations.
 		maybeWhiteouts = maybeWhiteouts[:0]
-		if err := layerFD.IterDirents(ctx, vfs.IterDirentsCallbackFunc(func(dirent vfs.Dirent) error {
+		err = layerFD.IterDirents(ctx, vfs.IterDirentsCallbackFunc(func(dirent vfs.Dirent) error {
 			if dirent.Name == "." || dirent.Name == ".." {
 				return nil
 			}
@@ -201,7 +202,8 @@ func (d *dentry) getDirents(ctx context.Context) ([]vfs.Dirent, error) {
 			dirent.NextOff = int64(len(dirents) + 1)
 			dirents = append(dirents, dirent)
 			return nil
-		})); err != nil {
+		}))
+		if err != nil {
 			readdirErr = err
 			return false
 		}
diff --git a/pkg/sentry/platform/ring0/defs_impl_arm64.go b/pkg/sentry/platform/ring0/defs_impl_arm64.go
index eba2eac30..2dac9ad14 100644
--- a/pkg/sentry/platform/ring0/defs_impl_arm64.go
+++ b/pkg/sentry/platform/ring0/defs_impl_arm64.go
@@ -3,11 +3,11 @@ package ring0
 import (
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
-	"io"
 	"reflect"
 
 	"fmt"
 	"gvisor.dev/gvisor/pkg/usermem"
+	"io"
 )
 
 // Useful bits.
diff --git a/runsc/boot/vfs.go b/runsc/boot/vfs.go
index e7d6035bb..08dce8b6c 100644
--- a/runsc/boot/vfs.go
+++ b/runsc/boot/vfs.go
@@ -400,21 +400,28 @@ func (c *containerMounter) mountTmpVFS2(ctx context.Context, conf *Config, creds
 		Path:  fspath.Parse("/tmp"),
 	}
 	// TODO(gvisor.dev/issue/2782): Use O_PATH when available.
-	statx, err := c.k.VFS().StatAt(ctx, creds, &pop, &vfs.StatOptions{})
+	fd, err := c.k.VFS().OpenAt(ctx, creds, &pop, &vfs.OpenOptions{Flags: linux.O_RDONLY | linux.O_DIRECTORY})
 	switch err {
 	case nil:
-		// Found '/tmp' in filesystem, check if it's empty.
-		if linux.FileMode(statx.Mode).FileType() != linux.ModeDirectory {
-			// Not a dir?! Leave it be.
+		defer fd.DecRef(ctx)
+
+		err := fd.IterDirents(ctx, vfs.IterDirentsCallbackFunc(func(dirent vfs.Dirent) error {
+			if dirent.Name != "." && dirent.Name != ".." {
+				return syserror.ENOTEMPTY
+			}
 			return nil
-		}
-		if statx.Nlink > 2 {
+		}))
+		switch err {
+		case nil:
+			log.Infof(`Mounting internal tmpfs on top of empty "/tmp"`)
+		case syserror.ENOTEMPTY:
 			// If more than "." and ".." is found, skip internal tmpfs to prevent
 			// hiding existing files.
 			log.Infof(`Skipping internal tmpfs mount for "/tmp" because it's not empty`)
 			return nil
+		default:
+			return err
 		}
-		log.Infof(`Mounting internal tmpfs on top of empty "/tmp"`)
 		fallthrough
 
 	case syserror.ENOENT:
@@ -429,8 +436,12 @@ func (c *containerMounter) mountTmpVFS2(ctx context.Context, conf *Config, creds
 		}
 		return c.mountSubmountVFS2(ctx, conf, mns, creds, &mountAndFD{Mount: tmpMount})
 
+	case syserror.ENOTDIR:
+		// Not a dir?! Let it be.
+		return nil
+
 	default:
-		return fmt.Errorf(`stating "/tmp" inside container: %w`, err)
+		return fmt.Errorf(`opening "/tmp" inside container: %w`, err)
 	}
 }