Merge release-20200810.0-94-gbae25d2a0 (automated)

4 files changed, 27 insertions, 21 deletions

diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go
index 359e2c3f2..5706130bf 100644
--- a/pkg/abi/linux/linux_abi_autogen_unsafe.go
+++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go
@@ -152,7 +152,7 @@ func (s *Statx) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (s *Statx) Packed() bool {
-    return s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed()
+    return s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -178,7 +178,7 @@ 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.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() && s.Ctime.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 := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
         s.MarshalBytes(buf) // escapes: fallback.
@@ -208,7 +208,7 @@ 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.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.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.
@@ -234,7 +234,7 @@ 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)
@@ -2046,7 +2046,7 @@ 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.
@@ -2208,7 +2208,7 @@ 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.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -2264,7 +2264,7 @@ func (i *IPTIP) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) {
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
 func (i *IPTIP) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {
-    if !i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() {
+    if !i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() {
         // Type IPTIP 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.
@@ -2290,7 +2290,7 @@ func (i *IPTIP) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (i *IPTIP) WriteTo(w io.Writer) (int64, error) {
-    if !i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() {
+    if !i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() {
         // Type IPTIP doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, i.SizeBytes())
         i.MarshalBytes(buf)
@@ -3004,7 +3004,7 @@ func (i *IP6TEntry) Packed() bool {
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
 func (i *IP6TEntry) MarshalUnsafe(dst []byte) {
-    if i.IPv6.Packed() && i.Counters.Packed() {
+    if i.Counters.Packed() && i.IPv6.Packed() {
         safecopy.CopyIn(dst, unsafe.Pointer(i))
     } else {
         // Type IP6TEntry doesn't have a packed layout in memory, fallback to MarshalBytes.
@@ -3196,12 +3196,12 @@ func (i *IP6TIP) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (i *IP6TIP) 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 *IP6TIP) MarshalUnsafe(dst []byte) {
-    if i.Src.Packed() && i.Dst.Packed() && i.SrcMask.Packed() && i.DstMask.Packed() {
+    if i.SrcMask.Packed() && i.DstMask.Packed() && i.Src.Packed() && i.Dst.Packed() {
         safecopy.CopyIn(dst, unsafe.Pointer(i))
     } else {
         // Type IP6TIP doesn't have a packed layout in memory, fallback to MarshalBytes.
diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go
index c6696b9d8..81d34cfe3 100644
--- a/pkg/sentry/fsimpl/gofer/gofer.go
+++ b/pkg/sentry/fsimpl/gofer/gofer.go
@@ -703,6 +703,13 @@ type dentry struct {
 	locks vfs.FileLocks
 
 	// Inotify watches for this dentry.
+	//
+	// Note that inotify may behave unexpectedly in the presence of hard links,
+	// because dentries corresponding to the same file have separate inotify
+	// watches when they should share the same set. This is the case because it is
+	// impossible for us to know for sure whether two dentries correspond to the
+	// same underlying file (see the gofer filesystem section fo vfs/inotify.md for
+	// a more in-depth discussion on this matter).
 	watches vfs.Watches
 }
 
diff --git a/pkg/sentry/platform/ring0/defs_impl_arm64.go b/pkg/sentry/platform/ring0/defs_impl_arm64.go
index 2dac9ad14..9fb351879 100644
--- a/pkg/sentry/platform/ring0/defs_impl_arm64.go
+++ b/pkg/sentry/platform/ring0/defs_impl_arm64.go
@@ -1,13 +1,12 @@
 package ring0
 
 import (
+	"fmt"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
-	"reflect"
-
-	"fmt"
 	"gvisor.dev/gvisor/pkg/usermem"
 	"io"
+	"reflect"
 )
 
 // Useful bits.
diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go
index 80c65164a..da6bd85e1 100644
--- a/pkg/sentry/syscalls/linux/linux64.go
+++ b/pkg/sentry/syscalls/linux/linux64.go
@@ -305,9 +305,9 @@ var AMD64 = &kernel.SyscallTable{
 		250: syscalls.Error("keyctl", syserror.EACCES, "Not available to user.", nil),
 		251: syscalls.CapError("ioprio_set", linux.CAP_SYS_ADMIN, "", nil), // requires cap_sys_nice or cap_sys_admin (depending)
 		252: syscalls.CapError("ioprio_get", linux.CAP_SYS_ADMIN, "", nil), // requires cap_sys_nice or cap_sys_admin (depending)
-		253: syscalls.PartiallySupported("inotify_init", InotifyInit, "inotify events are only available inside the sandbox.", nil),
-		254: syscalls.PartiallySupported("inotify_add_watch", InotifyAddWatch, "inotify events are only available inside the sandbox.", nil),
-		255: syscalls.PartiallySupported("inotify_rm_watch", InotifyRmWatch, "inotify events are only available inside the sandbox.", nil),
+		253: syscalls.PartiallySupported("inotify_init", InotifyInit, "Inotify events are only available inside the sandbox. Hard links are treated as different watch targets in gofer fs.", nil),
+		254: syscalls.PartiallySupported("inotify_add_watch", InotifyAddWatch, "Inotify events are only available inside the sandbox. Hard links are treated as different watch targets in gofer fs.", nil),
+		255: syscalls.PartiallySupported("inotify_rm_watch", InotifyRmWatch, "Inotify events are only available inside the sandbox. Hard links are treated as different watch targets in gofer fs.", nil),
 		256: syscalls.CapError("migrate_pages", linux.CAP_SYS_NICE, "", nil),
 		257: syscalls.Supported("openat", Openat),
 		258: syscalls.Supported("mkdirat", Mkdirat),
@@ -346,7 +346,7 @@ var AMD64 = &kernel.SyscallTable{
 		291: syscalls.Supported("epoll_create1", EpollCreate1),
 		292: syscalls.Supported("dup3", Dup3),
 		293: syscalls.Supported("pipe2", Pipe2),
-		294: syscalls.Supported("inotify_init1", InotifyInit1),
+		294: syscalls.PartiallySupported("inotify_init1", InotifyInit1, "Inotify events are only available inside the sandbox. Hard links are treated as different watch targets in gofer fs.", nil),
 		295: syscalls.Supported("preadv", Preadv),
 		296: syscalls.Supported("pwritev", Pwritev),
 		297: syscalls.Supported("rt_tgsigqueueinfo", RtTgsigqueueinfo),
@@ -454,9 +454,9 @@ var ARM64 = &kernel.SyscallTable{
 		23:  syscalls.Supported("dup", Dup),
 		24:  syscalls.Supported("dup3", Dup3),
 		25:  syscalls.PartiallySupported("fcntl", Fcntl, "Not all options are supported.", nil),
-		26:  syscalls.Supported("inotify_init1", InotifyInit1),
-		27:  syscalls.PartiallySupported("inotify_add_watch", InotifyAddWatch, "inotify events are only available inside the sandbox.", nil),
-		28:  syscalls.PartiallySupported("inotify_rm_watch", InotifyRmWatch, "inotify events are only available inside the sandbox.", nil),
+		26:  syscalls.PartiallySupported("inotify_init1", InotifyInit1, "Inotify events are only available inside the sandbox. Hard links are treated as different watch targets in gofer fs.", nil),
+		27:  syscalls.PartiallySupported("inotify_add_watch", InotifyAddWatch, "Inotify events are only available inside the sandbox. Hard links are treated as different watch targets in gofer fs.", nil),
+		28:  syscalls.PartiallySupported("inotify_rm_watch", InotifyRmWatch, "Inotify events are only available inside the sandbox. Hard links are treated as different watch targets in gofer fs.", nil),
 		29:  syscalls.PartiallySupported("ioctl", Ioctl, "Only a few ioctls are implemented for backing devices and file systems.", nil),
 		30:  syscalls.CapError("ioprio_set", linux.CAP_SYS_ADMIN, "", nil), // requires cap_sys_nice or cap_sys_admin (depending)
 		31:  syscalls.CapError("ioprio_get", linux.CAP_SYS_ADMIN, "", nil), // requires cap_sys_nice or cap_sys_admin (depending)