Merge release-20200804.0-63-g49947d2eb (automated)

3 files changed, 41 insertions, 47 deletions

diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go
index 2dc1f9531..8c527106a 100644
--- a/pkg/abi/linux/linux_abi_autogen_unsafe.go
+++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go
@@ -145,12 +145,12 @@ func (s *Statx) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (s *Statx) Packed() bool {
-    return s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed()
+    return s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
 func (s *Statx) MarshalUnsafe(dst []byte) {
-    if s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() && s.Ctime.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.
@@ -160,7 +160,7 @@ func (s *Statx) MarshalUnsafe(dst []byte) {
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
 func (s *Statx) UnmarshalUnsafe(src []byte) {
-    if s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() {
+    if s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() {
         safecopy.CopyOut(unsafe.Pointer(s), src)
     } else {
         // Type Statx doesn't have a packed layout in memory, fallback to UnmarshalBytes.
@@ -201,7 +201,7 @@ func (s *Statx) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) {
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
 func (s *Statx) CopyIn(task marshal.Task, addr usermem.Addr) (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 UnmarshalBytes.
         buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
         length, err := task.CopyInBytes(addr, buf) // escapes: okay.
@@ -227,7 +227,7 @@ func (s *Statx) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (s *Statx) WriteTo(w io.Writer) (int64, error) {
-    if !s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() {
+    if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() {
         // Type Statx doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, s.SizeBytes())
         s.MarshalBytes(buf)
@@ -625,7 +625,7 @@ func (f *FUSEHeaderIn) Packed() bool {
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
 func (f *FUSEHeaderIn) MarshalUnsafe(dst []byte) {
-    if f.Unique.Packed() && f.Opcode.Packed() {
+    if f.Opcode.Packed() && f.Unique.Packed() {
         safecopy.CopyIn(dst, unsafe.Pointer(f))
     } else {
         // Type FUSEHeaderIn doesn't have a packed layout in memory, fallback to MarshalBytes.
@@ -676,7 +676,7 @@ func (f *FUSEHeaderIn) CopyOut(task marshal.Task, addr usermem.Addr) (int, error
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
 func (f *FUSEHeaderIn) CopyIn(task marshal.Task, addr usermem.Addr) (int, 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 UnmarshalBytes.
         buf := task.CopyScratchBuffer(f.SizeBytes()) // escapes: okay.
         length, err := task.CopyInBytes(addr, buf) // escapes: okay.
@@ -1686,7 +1686,7 @@ func (i *IPTEntry) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) {
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
 func (i *IPTEntry) CopyIn(task marshal.Task, addr usermem.Addr) (int, 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 UnmarshalBytes.
         buf := task.CopyScratchBuffer(i.SizeBytes()) // escapes: okay.
         length, err := task.CopyInBytes(addr, buf) // escapes: okay.
@@ -1818,7 +1818,7 @@ func (i *IPTIP) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (i *IPTIP) Packed() bool {
-    return i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed()
+    return i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -1833,7 +1833,7 @@ func (i *IPTIP) MarshalUnsafe(dst []byte) {
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
 func (i *IPTIP) UnmarshalUnsafe(src []byte) {
-    if i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed() {
+    if i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() {
         safecopy.CopyOut(unsafe.Pointer(i), src)
     } else {
         // Type IPTIP doesn't have a packed layout in memory, fallback to UnmarshalBytes.
diff --git a/pkg/p9/transport.go b/pkg/p9/transport.go
index 7cec0e86d..02e665345 100644
--- a/pkg/p9/transport.go
+++ b/pkg/p9/transport.go
@@ -66,14 +66,17 @@ const (
 var dataPool = sync.Pool{
 	New: func() interface{} {
 		// These buffers are used for decoding without a payload.
-		return make([]byte, initialBufferLength)
+		// We need to return a pointer to avoid unnecessary allocations
+		// (see https://staticcheck.io/docs/checks#SA6002).
+		b := make([]byte, initialBufferLength)
+		return &b
 	},
 }
 
 // send sends the given message over the socket.
 func send(s *unet.Socket, tag Tag, m message) error {
-	data := dataPool.Get().([]byte)
-	dataBuf := buffer{data: data[:0]}
+	data := dataPool.Get().(*[]byte)
+	dataBuf := buffer{data: (*data)[:0]}
 
 	if log.IsLogging(log.Debug) {
 		log.Debugf("send [FD %d] [Tag %06d] %s", s.FD(), tag, m.String())
@@ -141,7 +144,7 @@ func send(s *unet.Socket, tag Tag, m message) error {
 	}
 
 	// All set.
-	dataPool.Put(dataBuf.data)
+	dataPool.Put(&dataBuf.data)
 	return nil
 }
 
@@ -227,12 +230,29 @@ func recv(s *unet.Socket, msize uint32, lookup lookupTagAndType) (Tag, message,
 
 	// Not yet initialized.
 	var dataBuf buffer
+	var vecs [][]byte
+
+	appendBuffer := func(size int) *[]byte {
+		// Pull a data buffer from the pool.
+		datap := dataPool.Get().(*[]byte)
+		data := *datap
+		if size > len(data) {
+			// Create a larger data buffer.
+			data = make([]byte, size)
+			datap = &data
+		} else {
+			// Limit the data buffer.
+			data = data[:size]
+		}
+		dataBuf = buffer{data: data}
+		vecs = append(vecs, data)
+		return datap
+	}
 
 	// Read the rest of the payload.
 	//
 	// This requires some special care to ensure that the vectors all line
 	// up the way they should. We do this to minimize copying data around.
-	var vecs [][]byte
 	if payloader, ok := m.(payloader); ok {
 		fixedSize := payloader.FixedSize()
 
@@ -246,22 +266,8 @@ func recv(s *unet.Socket, msize uint32, lookup lookupTagAndType) (Tag, message,
 		}
 
 		if fixedSize != 0 {
-			// Pull a data buffer from the pool.
-			data := dataPool.Get().([]byte)
-			if int(fixedSize) > len(data) {
-				// Create a larger data buffer, ensuring
-				// sufficient capicity for the message.
-				data = make([]byte, fixedSize)
-				defer dataPool.Put(data)
-				dataBuf = buffer{data: data}
-				vecs = append(vecs, data)
-			} else {
-				// Limit the data buffer, and make sure it
-				// gets filled before the payload buffer.
-				defer dataPool.Put(data)
-				dataBuf = buffer{data: data[:fixedSize]}
-				vecs = append(vecs, data[:fixedSize])
-			}
+			datap := appendBuffer(int(fixedSize))
+			defer dataPool.Put(datap)
 		}
 
 		// Include the payload.
@@ -274,20 +280,8 @@ func recv(s *unet.Socket, msize uint32, lookup lookupTagAndType) (Tag, message,
 			vecs = append(vecs, p)
 		}
 	} else if remaining != 0 {
-		// Pull a data buffer from the pool.
-		data := dataPool.Get().([]byte)
-		if int(remaining) > len(data) {
-			// Create a larger data buffer.
-			data = make([]byte, remaining)
-			defer dataPool.Put(data)
-			dataBuf = buffer{data: data}
-			vecs = append(vecs, data)
-		} else {
-			// Limit the data buffer.
-			defer dataPool.Put(data)
-			dataBuf = buffer{data: data[:remaining]}
-			vecs = append(vecs, data[:remaining])
-		}
+		datap := appendBuffer(int(remaining))
+		defer dataPool.Put(datap)
 	}
 
 	if len(vecs) > 0 {
diff --git a/pkg/sentry/platform/ring0/defs_impl_arm64.go b/pkg/sentry/platform/ring0/defs_impl_arm64.go
index 424b66f76..eba2eac30 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"
-	"reflect"
 )
 
 // Useful bits.