Merge branch 'iptables-write-input-drop' into iptables-write-filter-proto

author: Kevin Krakauer <krakauer@google.com> 2020-01-13 16:06:29 -0800
committer: Kevin Krakauer <krakauer@google.com> 2020-01-13 16:06:29 -0800
commit: d51eaa59c020cca9b7bc27cec0338ead089f3ed6 (patch)
tree: 3b41776af9426496567573ed17698562daf39006 /pkg/sentry
parent: d793677cd424fef10ac0b080871d181db0bcdec0 (diff)
parent: 1c3d3c70b93d483894dd49fb444171347f0ca250 (diff)
172 files changed, 968 insertions, 227 deletions
diff --git a/pkg/sentry/arch/BUILD b/pkg/sentry/arch/BUILD
index 18c73cc24..ae3e364cd 100644
--- a/pkg/sentry/arch/BUILD
+++ b/pkg/sentry/arch/BUILD
@@ -32,6 +32,7 @@ go_library(
         "//pkg/sentry/context",
         "//pkg/sentry/limits",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
     ],
 )
diff --git a/pkg/sentry/arch/arch_x86.go b/pkg/sentry/arch/arch_x86.go
index 9294ac773..9f41e566f 100644
--- a/pkg/sentry/arch/arch_x86.go
+++ b/pkg/sentry/arch/arch_x86.go
@@ -19,7 +19,6 @@ package arch
 import (
 	"fmt"
 	"io"
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/binary"
@@ -27,6 +26,7 @@ import (
 	"gvisor.dev/gvisor/pkg/log"
 	rpb "gvisor.dev/gvisor/pkg/sentry/arch/registers_go_proto"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/control/BUILD b/pkg/sentry/control/BUILD
index 5522cecd0..2561a6109 100644
--- a/pkg/sentry/control/BUILD
+++ b/pkg/sentry/control/BUILD
@@ -30,6 +30,7 @@ go_library(
         "//pkg/sentry/strace",
         "//pkg/sentry/usage",
         "//pkg/sentry/watchdog",
+        "//pkg/sync",
         "//pkg/tcpip/link/sniffer",
         "//pkg/urpc",
     ],
diff --git a/pkg/sentry/control/pprof.go b/pkg/sentry/control/pprof.go
index e1f2fea60..151808911 100644
--- a/pkg/sentry/control/pprof.go
+++ b/pkg/sentry/control/pprof.go
@@ -19,10 +19,10 @@ import (
 	"runtime"
 	"runtime/pprof"
 	"runtime/trace"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/fd"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/urpc"
 )
 
diff --git a/pkg/sentry/device/BUILD b/pkg/sentry/device/BUILD
index 1098ed777..97fa1512c 100644
--- a/pkg/sentry/device/BUILD
+++ b/pkg/sentry/device/BUILD
@@ -8,7 +8,10 @@ go_library(
     srcs = ["device.go"],
     importpath = "gvisor.dev/gvisor/pkg/sentry/device",
     visibility = ["//pkg/sentry:internal"],
-    deps = ["//pkg/abi/linux"],
+    deps = [
+        "//pkg/abi/linux",
+        "//pkg/sync",
+    ],
 )
 
 go_test(
diff --git a/pkg/sentry/device/device.go b/pkg/sentry/device/device.go
index 47945d1a7..69e71e322 100644
--- a/pkg/sentry/device/device.go
+++ b/pkg/sentry/device/device.go
@@ -19,10 +19,10 @@ package device
 import (
 	"bytes"
 	"fmt"
-	"sync"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // Registry tracks all simple devices and related state on the system for
diff --git a/pkg/sentry/fs/BUILD b/pkg/sentry/fs/BUILD
index c035ffff7..7d5d72d5a 100644
--- a/pkg/sentry/fs/BUILD
+++ b/pkg/sentry/fs/BUILD
@@ -68,7 +68,7 @@ go_library(
         "//pkg/sentry/usage",
         "//pkg/sentry/usermem",
         "//pkg/state",
-        "//pkg/syncutil",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
@@ -115,6 +115,7 @@ go_test(
         "//pkg/sentry/fs/tmpfs",
         "//pkg/sentry/kernel/contexttest",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
     ],
 )
diff --git a/pkg/sentry/fs/copy_up.go b/pkg/sentry/fs/copy_up.go
index 9ac62c84d..734177e90 100644
--- a/pkg/sentry/fs/copy_up.go
+++ b/pkg/sentry/fs/copy_up.go
@@ -17,12 +17,12 @@ package fs
 import (
 	"fmt"
 	"io"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fs/copy_up_test.go b/pkg/sentry/fs/copy_up_test.go
index 1d80bf15a..738580c5f 100644
--- a/pkg/sentry/fs/copy_up_test.go
+++ b/pkg/sentry/fs/copy_up_test.go
@@ -19,13 +19,13 @@ import (
 	"crypto/rand"
 	"fmt"
 	"io"
-	"sync"
 	"testing"
 
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	_ "gvisor.dev/gvisor/pkg/sentry/fs/tmpfs"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/contexttest"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 const (
diff --git a/pkg/sentry/fs/dirent.go b/pkg/sentry/fs/dirent.go
index 3cb73bd78..31fc4d87b 100644
--- a/pkg/sentry/fs/dirent.go
+++ b/pkg/sentry/fs/dirent.go
@@ -18,7 +18,6 @@ import (
 	"fmt"
 	"path"
 	"sort"
-	"sync"
 	"sync/atomic"
 	"syscall"
 
@@ -28,6 +27,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
 	"gvisor.dev/gvisor/pkg/sentry/uniqueid"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fs/dirent_cache.go b/pkg/sentry/fs/dirent_cache.go
index 60a15a275..25514ace4 100644
--- a/pkg/sentry/fs/dirent_cache.go
+++ b/pkg/sentry/fs/dirent_cache.go
@@ -16,7 +16,8 @@ package fs
 
 import (
 	"fmt"
-	"sync"
+
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // DirentCache is an LRU cache of Dirents. The Dirent's refCount is
diff --git a/pkg/sentry/fs/dirent_cache_limiter.go b/pkg/sentry/fs/dirent_cache_limiter.go
index ebb80bd50..525ee25f9 100644
--- a/pkg/sentry/fs/dirent_cache_limiter.go
+++ b/pkg/sentry/fs/dirent_cache_limiter.go
@@ -16,7 +16,8 @@ package fs
 
 import (
 	"fmt"
-	"sync"
+
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // DirentCacheLimiter acts as a global limit for all dirent caches in the
diff --git a/pkg/sentry/fs/fdpipe/BUILD b/pkg/sentry/fs/fdpipe/BUILD
index 277ee4c31..cc43de69d 100644
--- a/pkg/sentry/fs/fdpipe/BUILD
+++ b/pkg/sentry/fs/fdpipe/BUILD
@@ -23,6 +23,7 @@ go_library(
         "//pkg/sentry/fs/fsutil",
         "//pkg/sentry/safemem",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
diff --git a/pkg/sentry/fs/fdpipe/pipe.go b/pkg/sentry/fs/fdpipe/pipe.go
index 669ffcb75..5b6cfeb0a 100644
--- a/pkg/sentry/fs/fdpipe/pipe.go
+++ b/pkg/sentry/fs/fdpipe/pipe.go
@@ -17,7 +17,6 @@ package fdpipe
 
 import (
 	"os"
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/fd"
@@ -29,6 +28,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/fs/fdpipe/pipe_state.go b/pkg/sentry/fs/fdpipe/pipe_state.go
index 29175fb3d..cee87f726 100644
--- a/pkg/sentry/fs/fdpipe/pipe_state.go
+++ b/pkg/sentry/fs/fdpipe/pipe_state.go
@@ -17,10 +17,10 @@ package fdpipe
 import (
 	"fmt"
 	"io/ioutil"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // beforeSave is invoked by stateify.
diff --git a/pkg/sentry/fs/file.go b/pkg/sentry/fs/file.go
index a2f966cb6..7c4586296 100644
--- a/pkg/sentry/fs/file.go
+++ b/pkg/sentry/fs/file.go
@@ -16,7 +16,6 @@ package fs
 
 import (
 	"math"
-	"sync"
 	"sync/atomic"
 	"time"
 
@@ -29,6 +28,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/uniqueid"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/fs/file_overlay.go b/pkg/sentry/fs/file_overlay.go
index 225e40186..8a633b1ba 100644
--- a/pkg/sentry/fs/file_overlay.go
+++ b/pkg/sentry/fs/file_overlay.go
@@ -16,13 +16,13 @@ package fs
 
 import (
 	"io"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/refs"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/fs/filesystems.go b/pkg/sentry/fs/filesystems.go
index b157fd228..c5b51620a 100644
--- a/pkg/sentry/fs/filesystems.go
+++ b/pkg/sentry/fs/filesystems.go
@@ -18,9 +18,9 @@ import (
 	"fmt"
 	"sort"
 	"strings"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/sentry/context"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // FilesystemFlags matches include/linux/fs.h:file_system_type.fs_flags.
diff --git a/pkg/sentry/fs/fs.go b/pkg/sentry/fs/fs.go
index 8b2a5e6b2..26abf49e2 100644
--- a/pkg/sentry/fs/fs.go
+++ b/pkg/sentry/fs/fs.go
@@ -54,10 +54,9 @@
 package fs
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/sentry/context"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 var (
diff --git a/pkg/sentry/fs/fsutil/BUILD b/pkg/sentry/fs/fsutil/BUILD
index 9ca695a95..945b6270d 100644
--- a/pkg/sentry/fs/fsutil/BUILD
+++ b/pkg/sentry/fs/fsutil/BUILD
@@ -93,6 +93,7 @@ go_library(
         "//pkg/sentry/usage",
         "//pkg/sentry/usermem",
         "//pkg/state",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
diff --git a/pkg/sentry/fs/fsutil/host_file_mapper.go b/pkg/sentry/fs/fsutil/host_file_mapper.go
index b06a71cc2..837fc70b5 100644
--- a/pkg/sentry/fs/fsutil/host_file_mapper.go
+++ b/pkg/sentry/fs/fsutil/host_file_mapper.go
@@ -16,7 +16,6 @@ package fsutil
 
 import (
 	"fmt"
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/log"
@@ -24,6 +23,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // HostFileMapper caches mappings of an arbitrary host file descriptor. It is
diff --git a/pkg/sentry/fs/fsutil/host_mappable.go b/pkg/sentry/fs/fsutil/host_mappable.go
index 30475f340..a625f0e26 100644
--- a/pkg/sentry/fs/fsutil/host_mappable.go
+++ b/pkg/sentry/fs/fsutil/host_mappable.go
@@ -16,7 +16,6 @@ package fsutil
 
 import (
 	"math"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
@@ -24,6 +23,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // HostMappable implements memmap.Mappable and platform.File over a
diff --git a/pkg/sentry/fs/fsutil/inode.go b/pkg/sentry/fs/fsutil/inode.go
index 4e100a402..adf5ec69c 100644
--- a/pkg/sentry/fs/fsutil/inode.go
+++ b/pkg/sentry/fs/fsutil/inode.go
@@ -15,13 +15,12 @@
 package fsutil
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/fs/fsutil/inode_cached.go b/pkg/sentry/fs/fsutil/inode_cached.go
index 798920d18..20a014402 100644
--- a/pkg/sentry/fs/fsutil/inode_cached.go
+++ b/pkg/sentry/fs/fsutil/inode_cached.go
@@ -17,7 +17,6 @@ package fsutil
 import (
 	"fmt"
 	"io"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/sentry/context"
@@ -30,6 +29,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // Lock order (compare the lock order model in mm/mm.go):
diff --git a/pkg/sentry/fs/gofer/BUILD b/pkg/sentry/fs/gofer/BUILD
index 4a005c605..fd870e8e1 100644
--- a/pkg/sentry/fs/gofer/BUILD
+++ b/pkg/sentry/fs/gofer/BUILD
@@ -44,6 +44,7 @@ go_library(
         "//pkg/sentry/safemem",
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserr",
         "//pkg/syserror",
         "//pkg/unet",
diff --git a/pkg/sentry/fs/gofer/inode.go b/pkg/sentry/fs/gofer/inode.go
index 91263ebdc..245fe2ef1 100644
--- a/pkg/sentry/fs/gofer/inode.go
+++ b/pkg/sentry/fs/gofer/inode.go
@@ -16,7 +16,6 @@ package gofer
 
 import (
 	"errors"
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -31,6 +30,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs/host"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fs/gofer/session.go b/pkg/sentry/fs/gofer/session.go
index 4e358a46a..edc796ce0 100644
--- a/pkg/sentry/fs/gofer/session.go
+++ b/pkg/sentry/fs/gofer/session.go
@@ -16,7 +16,6 @@ package gofer
 
 import (
 	"fmt"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/p9"
 	"gvisor.dev/gvisor/pkg/refs"
@@ -25,6 +24,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/unet"
 )
 
diff --git a/pkg/sentry/fs/host/BUILD b/pkg/sentry/fs/host/BUILD
index 23daeb528..2b581aa69 100644
--- a/pkg/sentry/fs/host/BUILD
+++ b/pkg/sentry/fs/host/BUILD
@@ -50,6 +50,7 @@ go_library(
         "//pkg/sentry/unimpl",
         "//pkg/sentry/uniqueid",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserr",
         "//pkg/syserror",
         "//pkg/tcpip",
diff --git a/pkg/sentry/fs/host/inode.go b/pkg/sentry/fs/host/inode.go
index a6e4a09e3..873a1c52d 100644
--- a/pkg/sentry/fs/host/inode.go
+++ b/pkg/sentry/fs/host/inode.go
@@ -15,7 +15,6 @@
 package host
 
 import (
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -28,6 +27,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/fs/host/socket.go b/pkg/sentry/fs/host/socket.go
index 107336a3e..c076d5bdd 100644
--- a/pkg/sentry/fs/host/socket.go
+++ b/pkg/sentry/fs/host/socket.go
@@ -16,7 +16,6 @@ package host
 
 import (
 	"fmt"
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -30,6 +29,7 @@ import (
 	unixsocket "gvisor.dev/gvisor/pkg/sentry/socket/unix"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
 	"gvisor.dev/gvisor/pkg/sentry/uniqueid"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserr"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/tcpip"
diff --git a/pkg/sentry/fs/host/tty.go b/pkg/sentry/fs/host/tty.go
index 90331e3b2..753ef8cd6 100644
--- a/pkg/sentry/fs/host/tty.go
+++ b/pkg/sentry/fs/host/tty.go
@@ -15,8 +15,6 @@
 package host
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/context"
@@ -24,6 +22,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/unimpl"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fs/inode.go b/pkg/sentry/fs/inode.go
index 91e2fde2f..468043df0 100644
--- a/pkg/sentry/fs/inode.go
+++ b/pkg/sentry/fs/inode.go
@@ -15,8 +15,6 @@
 package fs
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/metric"
@@ -26,6 +24,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fs/inode_inotify.go b/pkg/sentry/fs/inode_inotify.go
index 0f2a66a79..efd3c962b 100644
--- a/pkg/sentry/fs/inode_inotify.go
+++ b/pkg/sentry/fs/inode_inotify.go
@@ -16,7 +16,8 @@ package fs
 
 import (
 	"fmt"
-	"sync"
+
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // Watches is the collection of inotify watches on an inode.
diff --git a/pkg/sentry/fs/inotify.go b/pkg/sentry/fs/inotify.go
index ba3e0233d..cc7dd1c92 100644
--- a/pkg/sentry/fs/inotify.go
+++ b/pkg/sentry/fs/inotify.go
@@ -16,7 +16,6 @@ package fs
 
 import (
 	"io"
-	"sync"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -25,6 +24,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/uniqueid"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/fs/inotify_watch.go b/pkg/sentry/fs/inotify_watch.go
index 0aa0a5e9b..900cba3ca 100644
--- a/pkg/sentry/fs/inotify_watch.go
+++ b/pkg/sentry/fs/inotify_watch.go
@@ -15,10 +15,10 @@
 package fs
 
 import (
-	"sync"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // Watch represent a particular inotify watch created by inotify_add_watch.
diff --git a/pkg/sentry/fs/lock/BUILD b/pkg/sentry/fs/lock/BUILD
index 8d62642e7..2c332a82a 100644
--- a/pkg/sentry/fs/lock/BUILD
+++ b/pkg/sentry/fs/lock/BUILD
@@ -44,6 +44,7 @@ go_library(
     visibility = ["//pkg/sentry:internal"],
     deps = [
         "//pkg/log",
+        "//pkg/sync",
         "//pkg/waiter",
     ],
 )
diff --git a/pkg/sentry/fs/lock/lock.go b/pkg/sentry/fs/lock/lock.go
index 636484424..41b040818 100644
--- a/pkg/sentry/fs/lock/lock.go
+++ b/pkg/sentry/fs/lock/lock.go
@@ -52,9 +52,9 @@ package lock
 import (
 	"fmt"
 	"math"
-	"sync"
 	"syscall"
 
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
 
diff --git a/pkg/sentry/fs/mounts.go b/pkg/sentry/fs/mounts.go
index ac0398bd9..db3dfd096 100644
--- a/pkg/sentry/fs/mounts.go
+++ b/pkg/sentry/fs/mounts.go
@@ -19,7 +19,6 @@ import (
 	"math"
 	"path"
 	"strings"
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -27,6 +26,7 @@ import (
 	"gvisor.dev/gvisor/pkg/refs"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fs/overlay.go b/pkg/sentry/fs/overlay.go
index 25573e986..4cad55327 100644
--- a/pkg/sentry/fs/overlay.go
+++ b/pkg/sentry/fs/overlay.go
@@ -17,13 +17,12 @@ package fs
 import (
 	"fmt"
 	"strings"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
-	"gvisor.dev/gvisor/pkg/syncutil"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
@@ -199,7 +198,7 @@ type overlayEntry struct {
 	upper *Inode
 
 	// dirCacheMu protects dirCache.
-	dirCacheMu syncutil.DowngradableRWMutex `state:"nosave"`
+	dirCacheMu sync.DowngradableRWMutex `state:"nosave"`
 
 	// dirCache is cache of DentAttrs from upper and lower Inodes.
 	dirCache *SortedDentryMap
diff --git a/pkg/sentry/fs/proc/BUILD b/pkg/sentry/fs/proc/BUILD
index 75cbb0622..94d46ab1b 100644
--- a/pkg/sentry/fs/proc/BUILD
+++ b/pkg/sentry/fs/proc/BUILD
@@ -51,6 +51,7 @@ go_library(
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/usage",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/tcpip/header",
         "//pkg/waiter",
diff --git a/pkg/sentry/fs/proc/seqfile/BUILD b/pkg/sentry/fs/proc/seqfile/BUILD
index fe7067be1..38b246dff 100644
--- a/pkg/sentry/fs/proc/seqfile/BUILD
+++ b/pkg/sentry/fs/proc/seqfile/BUILD
@@ -16,6 +16,7 @@ go_library(
         "//pkg/sentry/fs/proc/device",
         "//pkg/sentry/kernel/time",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
diff --git a/pkg/sentry/fs/proc/seqfile/seqfile.go b/pkg/sentry/fs/proc/seqfile/seqfile.go
index 5fe823000..f9af191d5 100644
--- a/pkg/sentry/fs/proc/seqfile/seqfile.go
+++ b/pkg/sentry/fs/proc/seqfile/seqfile.go
@@ -17,7 +17,6 @@ package seqfile
 
 import (
 	"io"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/context"
@@ -26,6 +25,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs/proc/device"
 	ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/fs/proc/sys_net.go b/pkg/sentry/fs/proc/sys_net.go
index bd93f83fa..a37e1fa06 100644
--- a/pkg/sentry/fs/proc/sys_net.go
+++ b/pkg/sentry/fs/proc/sys_net.go
@@ -17,7 +17,6 @@ package proc
 import (
 	"fmt"
 	"io"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/context"
@@ -27,6 +26,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs/ramfs"
 	"gvisor.dev/gvisor/pkg/sentry/inet"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
 
diff --git a/pkg/sentry/fs/ramfs/BUILD b/pkg/sentry/fs/ramfs/BUILD
index 012cb3e44..3fb7b0633 100644
--- a/pkg/sentry/fs/ramfs/BUILD
+++ b/pkg/sentry/fs/ramfs/BUILD
@@ -21,6 +21,7 @@ go_library(
         "//pkg/sentry/fs/fsutil",
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
diff --git a/pkg/sentry/fs/ramfs/dir.go b/pkg/sentry/fs/ramfs/dir.go
index 78e082b8e..dcbb8eb2e 100644
--- a/pkg/sentry/fs/ramfs/dir.go
+++ b/pkg/sentry/fs/ramfs/dir.go
@@ -17,7 +17,6 @@ package ramfs
 
 import (
 	"fmt"
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -25,6 +24,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fs/restore.go b/pkg/sentry/fs/restore.go
index f10168125..64c6a6ae9 100644
--- a/pkg/sentry/fs/restore.go
+++ b/pkg/sentry/fs/restore.go
@@ -15,7 +15,7 @@
 package fs
 
 import (
-	"sync"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // RestoreEnvironment is the restore environment for file systems. It consists
diff --git a/pkg/sentry/fs/tmpfs/BUILD b/pkg/sentry/fs/tmpfs/BUILD
index 59ce400c2..3400b940c 100644
--- a/pkg/sentry/fs/tmpfs/BUILD
+++ b/pkg/sentry/fs/tmpfs/BUILD
@@ -31,6 +31,7 @@ go_library(
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/usage",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
diff --git a/pkg/sentry/fs/tmpfs/inode_file.go b/pkg/sentry/fs/tmpfs/inode_file.go
index f86dfaa36..f1c87fe41 100644
--- a/pkg/sentry/fs/tmpfs/inode_file.go
+++ b/pkg/sentry/fs/tmpfs/inode_file.go
@@ -17,7 +17,6 @@ package tmpfs
 import (
 	"fmt"
 	"io"
-	"sync"
 	"time"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -31,6 +30,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fs/tty/BUILD b/pkg/sentry/fs/tty/BUILD
index 95ad98cb0..f6f60d0cf 100644
--- a/pkg/sentry/fs/tty/BUILD
+++ b/pkg/sentry/fs/tty/BUILD
@@ -30,6 +30,7 @@ go_library(
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/unimpl",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
diff --git a/pkg/sentry/fs/tty/dir.go b/pkg/sentry/fs/tty/dir.go
index 2f639c823..88aa66b24 100644
--- a/pkg/sentry/fs/tty/dir.go
+++ b/pkg/sentry/fs/tty/dir.go
@@ -19,7 +19,6 @@ import (
 	"fmt"
 	"math"
 	"strconv"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/context"
@@ -28,6 +27,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/fs/tty/line_discipline.go b/pkg/sentry/fs/tty/line_discipline.go
index 7cc0eb409..894964260 100644
--- a/pkg/sentry/fs/tty/line_discipline.go
+++ b/pkg/sentry/fs/tty/line_discipline.go
@@ -16,13 +16,13 @@ package tty
 
 import (
 	"bytes"
-	"sync"
 	"unicode/utf8"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/fs/tty/queue.go b/pkg/sentry/fs/tty/queue.go
index 231e4e6eb..8b5d4699a 100644
--- a/pkg/sentry/fs/tty/queue.go
+++ b/pkg/sentry/fs/tty/queue.go
@@ -15,13 +15,12 @@
 package tty
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/fsimpl/ext/BUILD b/pkg/sentry/fsimpl/ext/BUILD
index bc90330bc..903874141 100644
--- a/pkg/sentry/fsimpl/ext/BUILD
+++ b/pkg/sentry/fsimpl/ext/BUILD
@@ -50,6 +50,7 @@ go_library(
         "//pkg/sentry/syscalls/linux",
         "//pkg/sentry/usermem",
         "//pkg/sentry/vfs",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
diff --git a/pkg/sentry/fsimpl/ext/directory.go b/pkg/sentry/fsimpl/ext/directory.go
index 91802dc1e..8944171c8 100644
--- a/pkg/sentry/fsimpl/ext/directory.go
+++ b/pkg/sentry/fsimpl/ext/directory.go
@@ -15,8 +15,6 @@
 package ext
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/binary"
 	"gvisor.dev/gvisor/pkg/log"
@@ -25,6 +23,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/ext/disklayout"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fsimpl/ext/disklayout/extent.go b/pkg/sentry/fsimpl/ext/disklayout/extent.go
index 567523d32..4110649ab 100644
--- a/pkg/sentry/fsimpl/ext/disklayout/extent.go
+++ b/pkg/sentry/fsimpl/ext/disklayout/extent.go
@@ -29,8 +29,12 @@ package disklayout
 //       byte (i * sb.BlockSize()) to ((i+1) * sb.BlockSize()).
 
 const (
-	// ExtentStructsSize is the size of all the three extent on-disk structs.
-	ExtentStructsSize = 12
+	// ExtentHeaderSize is the size of the header of an extent tree node.
+	ExtentHeaderSize = 12
+
+	// ExtentEntrySize is the size of an entry in an extent tree node.
+	// This size is the same for both leaf and internal nodes.
+	ExtentEntrySize = 12
 
 	// ExtentMagic is the magic number which must be present in the header.
 	ExtentMagic = 0xf30a
@@ -57,7 +61,7 @@ type ExtentNode struct {
 	Entries []ExtentEntryPair
 }
 
-// ExtentEntry reprsents an extent tree node entry. The entry can either be
+// ExtentEntry represents an extent tree node entry. The entry can either be
 // an ExtentIdx or Extent itself. This exists to simplify navigation logic.
 type ExtentEntry interface {
 	// FileBlock returns the first file block number covered by this entry.
diff --git a/pkg/sentry/fsimpl/ext/disklayout/extent_test.go b/pkg/sentry/fsimpl/ext/disklayout/extent_test.go
index b0fad9b71..8762b90db 100644
--- a/pkg/sentry/fsimpl/ext/disklayout/extent_test.go
+++ b/pkg/sentry/fsimpl/ext/disklayout/extent_test.go
@@ -21,7 +21,7 @@ import (
 // TestExtentSize tests that the extent structs are of the correct
 // size.
 func TestExtentSize(t *testing.T) {
-	assertSize(t, ExtentHeader{}, ExtentStructsSize)
-	assertSize(t, ExtentIdx{}, ExtentStructsSize)
-	assertSize(t, Extent{}, ExtentStructsSize)
+	assertSize(t, ExtentHeader{}, ExtentHeaderSize)
+	assertSize(t, ExtentIdx{}, ExtentEntrySize)
+	assertSize(t, Extent{}, ExtentEntrySize)
 }
diff --git a/pkg/sentry/fsimpl/ext/extent_file.go b/pkg/sentry/fsimpl/ext/extent_file.go
index 3d3ebaca6..11dcc0346 100644
--- a/pkg/sentry/fsimpl/ext/extent_file.go
+++ b/pkg/sentry/fsimpl/ext/extent_file.go
@@ -57,7 +57,7 @@ func newExtentFile(regFile regularFile) (*extentFile, error) {
 func (f *extentFile) buildExtTree() error {
 	rootNodeData := f.regFile.inode.diskInode.Data()
 
-	binary.Unmarshal(rootNodeData[:disklayout.ExtentStructsSize], binary.LittleEndian, &f.root.Header)
+	binary.Unmarshal(rootNodeData[:disklayout.ExtentHeaderSize], binary.LittleEndian, &f.root.Header)
 
 	// Root node can not have more than 4 entries: 60 bytes = 1 header + 4 entries.
 	if f.root.Header.NumEntries > 4 {
@@ -67,7 +67,7 @@ func (f *extentFile) buildExtTree() error {
 	}
 
 	f.root.Entries = make([]disklayout.ExtentEntryPair, f.root.Header.NumEntries)
-	for i, off := uint16(0), disklayout.ExtentStructsSize; i < f.root.Header.NumEntries; i, off = i+1, off+disklayout.ExtentStructsSize {
+	for i, off := uint16(0), disklayout.ExtentEntrySize; i < f.root.Header.NumEntries; i, off = i+1, off+disklayout.ExtentEntrySize {
 		var curEntry disklayout.ExtentEntry
 		if f.root.Header.Height == 0 {
 			// Leaf node.
@@ -76,7 +76,7 @@ func (f *extentFile) buildExtTree() error {
 			// Internal node.
 			curEntry = &disklayout.ExtentIdx{}
 		}
-		binary.Unmarshal(rootNodeData[off:off+disklayout.ExtentStructsSize], binary.LittleEndian, curEntry)
+		binary.Unmarshal(rootNodeData[off:off+disklayout.ExtentEntrySize], binary.LittleEndian, curEntry)
 		f.root.Entries[i].Entry = curEntry
 	}
 
@@ -105,7 +105,7 @@ func (f *extentFile) buildExtTreeFromDisk(entry disklayout.ExtentEntry) (*diskla
 	}
 
 	entries := make([]disklayout.ExtentEntryPair, header.NumEntries)
-	for i, off := uint16(0), off+disklayout.ExtentStructsSize; i < header.NumEntries; i, off = i+1, off+disklayout.ExtentStructsSize {
+	for i, off := uint16(0), off+disklayout.ExtentEntrySize; i < header.NumEntries; i, off = i+1, off+disklayout.ExtentEntrySize {
 		var curEntry disklayout.ExtentEntry
 		if header.Height == 0 {
 			// Leaf node.
diff --git a/pkg/sentry/fsimpl/ext/filesystem.go b/pkg/sentry/fsimpl/ext/filesystem.go
index 616fc002a..9afb1a84c 100644
--- a/pkg/sentry/fsimpl/ext/filesystem.go
+++ b/pkg/sentry/fsimpl/ext/filesystem.go
@@ -17,13 +17,13 @@ package ext
 import (
 	"errors"
 	"io"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/fspath"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/ext/disklayout"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fsimpl/ext/regular_file.go b/pkg/sentry/fsimpl/ext/regular_file.go
index aec33e00a..d11153c90 100644
--- a/pkg/sentry/fsimpl/ext/regular_file.go
+++ b/pkg/sentry/fsimpl/ext/regular_file.go
@@ -16,7 +16,6 @@ package ext
 
 import (
 	"io"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/context"
@@ -24,6 +23,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fsimpl/kernfs/BUILD b/pkg/sentry/fsimpl/kernfs/BUILD
index 39c03ee9d..809178250 100644
--- a/pkg/sentry/fsimpl/kernfs/BUILD
+++ b/pkg/sentry/fsimpl/kernfs/BUILD
@@ -39,6 +39,7 @@ go_library(
         "//pkg/sentry/memmap",
         "//pkg/sentry/usermem",
         "//pkg/sentry/vfs",
+        "//pkg/sync",
         "//pkg/syserror",
     ],
 )
@@ -56,6 +57,7 @@ go_test(
         "//pkg/sentry/kernel/auth",
         "//pkg/sentry/usermem",
         "//pkg/sentry/vfs",
+        "//pkg/sync",
         "//pkg/syserror",
         "@com_github_google_go-cmp//cmp:go_default_library",
     ],
diff --git a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
index 752e0f659..1d469a0db 100644
--- a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
@@ -16,7 +16,6 @@ package kernfs
 
 import (
 	"fmt"
-	"sync"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -24,6 +23,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fsimpl/kernfs/kernfs.go b/pkg/sentry/fsimpl/kernfs/kernfs.go
index d69b299ae..bb12f39a2 100644
--- a/pkg/sentry/fsimpl/kernfs/kernfs.go
+++ b/pkg/sentry/fsimpl/kernfs/kernfs.go
@@ -53,7 +53,6 @@ package kernfs
 
 import (
 	"fmt"
-	"sync"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -61,6 +60,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // FilesystemType implements vfs.FilesystemType.
diff --git a/pkg/sentry/fsimpl/kernfs/kernfs_test.go b/pkg/sentry/fsimpl/kernfs/kernfs_test.go
index 4b6b95f5f..5c9d580e1 100644
--- a/pkg/sentry/fsimpl/kernfs/kernfs_test.go
+++ b/pkg/sentry/fsimpl/kernfs/kernfs_test.go
@@ -19,7 +19,6 @@ import (
 	"fmt"
 	"io"
 	"runtime"
-	"sync"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -31,6 +30,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fsimpl/proc/tasks.go b/pkg/sentry/fsimpl/proc/tasks.go
index 50b2a832f..d8f92d52f 100644
--- a/pkg/sentry/fsimpl/proc/tasks.go
+++ b/pkg/sentry/fsimpl/proc/tasks.go
@@ -27,7 +27,11 @@ import (
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
-const defaultPermission = 0444
+const (
+	defaultPermission = 0444
+	selfName          = "self"
+	threadSelfName    = "thread-self"
+)
 
 // InoGenerator generates unique inode numbers for a given filesystem.
 type InoGenerator interface {
@@ -45,6 +49,11 @@ type tasksInode struct {
 
 	inoGen InoGenerator
 	pidns  *kernel.PIDNamespace
+
+	// '/proc/self' and '/proc/thread-self' have custom directory offsets in
+	// Linux. So handle them outside of OrderedChildren.
+	selfSymlink       *vfs.Dentry
+	threadSelfSymlink *vfs.Dentry
 }
 
 var _ kernfs.Inode = (*tasksInode)(nil)
@@ -54,20 +63,20 @@ func newTasksInode(inoGen InoGenerator, k *kernel.Kernel, pidns *kernel.PIDNames
 	contents := map[string]*kernfs.Dentry{
 		//"cpuinfo":     newCPUInfo(ctx, msrc),
 		//"filesystems": seqfile.NewSeqFileInode(ctx, &filesystemsData{}, msrc),
-		"loadavg":     newDentry(root, inoGen.NextIno(), defaultPermission, &loadavgData{}),
-		"meminfo":     newDentry(root, inoGen.NextIno(), defaultPermission, &meminfoData{k: k}),
-		"mounts":      kernfs.NewStaticSymlink(root, inoGen.NextIno(), defaultPermission, "self/mounts"),
-		"self":        newSelfSymlink(root, inoGen.NextIno(), defaultPermission, pidns),
-		"stat":        newDentry(root, inoGen.NextIno(), defaultPermission, &statData{k: k}),
-		"thread-self": newThreadSelfSymlink(root, inoGen.NextIno(), defaultPermission, pidns),
+		"loadavg": newDentry(root, inoGen.NextIno(), defaultPermission, &loadavgData{}),
+		"meminfo": newDentry(root, inoGen.NextIno(), defaultPermission, &meminfoData{k: k}),
+		"mounts":  kernfs.NewStaticSymlink(root, inoGen.NextIno(), defaultPermission, "self/mounts"),
+		"stat":    newDentry(root, inoGen.NextIno(), defaultPermission, &statData{k: k}),
 		//"uptime":      newUptime(ctx, msrc),
 		//"version": newVersionData(root, inoGen.NextIno(), k),
 		"version": newDentry(root, inoGen.NextIno(), defaultPermission, &versionData{k: k}),
 	}
 
 	inode := &tasksInode{
-		pidns:  pidns,
-		inoGen: inoGen,
+		pidns:             pidns,
+		inoGen:            inoGen,
+		selfSymlink:       newSelfSymlink(root, inoGen.NextIno(), 0444, pidns).VFSDentry(),
+		threadSelfSymlink: newThreadSelfSymlink(root, inoGen.NextIno(), 0444, pidns).VFSDentry(),
 	}
 	inode.InodeAttrs.Init(root, inoGen.NextIno(), linux.ModeDirectory|0555)
 
@@ -86,6 +95,13 @@ func (i *tasksInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, erro
 	// Try to lookup a corresponding task.
 	tid, err := strconv.ParseUint(name, 10, 64)
 	if err != nil {
+		// If it failed to parse, check if it's one of the special handled files.
+		switch name {
+		case selfName:
+			return i.selfSymlink, nil
+		case threadSelfName:
+			return i.threadSelfSymlink, nil
+		}
 		return nil, syserror.ENOENT
 	}
 
@@ -104,41 +120,81 @@ func (i *tasksInode) Valid(ctx context.Context) bool {
 }
 
 // IterDirents implements kernfs.inodeDynamicLookup.
-//
-// TODO(gvisor.dev/issue/1195): Use tgid N offset = TGID_OFFSET + N.
-func (i *tasksInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, offset, relOffset int64) (int64, error) {
-	var tids []int
+func (i *tasksInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, offset, _ int64) (int64, error) {
+	// fs/proc/internal.h: #define FIRST_PROCESS_ENTRY 256
+	const FIRST_PROCESS_ENTRY = 256
+
+	// Use maxTaskID to shortcut searches that will result in 0 entries.
+	const maxTaskID = kernel.TasksLimit + 1
+	if offset >= maxTaskID {
+		return offset, nil
+	}
+
+	// According to Linux (fs/proc/base.c:proc_pid_readdir()), process directories
+	// start at offset FIRST_PROCESS_ENTRY with '/proc/self', followed by
+	// '/proc/thread-self' and then '/proc/[pid]'.
+	if offset < FIRST_PROCESS_ENTRY {
+		offset = FIRST_PROCESS_ENTRY
+	}
+
+	if offset == FIRST_PROCESS_ENTRY {
+		dirent := vfs.Dirent{
+			Name:    selfName,
+			Type:    linux.DT_LNK,
+			Ino:     i.inoGen.NextIno(),
+			NextOff: offset + 1,
+		}
+		if !cb.Handle(dirent) {
+			return offset, nil
+		}
+		offset++
+	}
+	if offset == FIRST_PROCESS_ENTRY+1 {
+		dirent := vfs.Dirent{
+			Name:    threadSelfName,
+			Type:    linux.DT_LNK,
+			Ino:     i.inoGen.NextIno(),
+			NextOff: offset + 1,
+		}
+		if !cb.Handle(dirent) {
+			return offset, nil
+		}
+		offset++
+	}
 
-	// Collect all tasks. Per linux we only include it in directory listings if
-	// it's the leader. But for whatever crazy reason, you can still walk to the
-	// given node.
+	// Collect all tasks that TGIDs are greater than the offset specified. Per
+	// Linux we only include in directory listings if it's the leader. But for
+	// whatever crazy reason, you can still walk to the given node.
+	var tids []int
+	startTid := offset - FIRST_PROCESS_ENTRY - 2
 	for _, tg := range i.pidns.ThreadGroups() {
+		tid := i.pidns.IDOfThreadGroup(tg)
+		if int64(tid) < startTid {
+			continue
+		}
 		if leader := tg.Leader(); leader != nil {
-			tids = append(tids, int(i.pidns.IDOfThreadGroup(tg)))
+			tids = append(tids, int(tid))
 		}
 	}
 
 	if len(tids) == 0 {
 		return offset, nil
 	}
-	if relOffset >= int64(len(tids)) {
-		return offset, nil
-	}
 
 	sort.Ints(tids)
-	for _, tid := range tids[relOffset:] {
+	for _, tid := range tids {
 		dirent := vfs.Dirent{
 			Name:    strconv.FormatUint(uint64(tid), 10),
 			Type:    linux.DT_DIR,
 			Ino:     i.inoGen.NextIno(),
-			NextOff: offset + 1,
+			NextOff: FIRST_PROCESS_ENTRY + 2 + int64(tid) + 1,
 		}
 		if !cb.Handle(dirent) {
 			return offset, nil
 		}
 		offset++
 	}
-	return offset, nil
+	return maxTaskID, nil
 }
 
 // Open implements kernfs.Inode.
diff --git a/pkg/sentry/fsimpl/proc/tasks_test.go b/pkg/sentry/fsimpl/proc/tasks_test.go
index 2560fcef9..ca8c87ec2 100644
--- a/pkg/sentry/fsimpl/proc/tasks_test.go
+++ b/pkg/sentry/fsimpl/proc/tasks_test.go
@@ -16,6 +16,7 @@ package proc
 
 import (
 	"fmt"
+	"math"
 	"path"
 	"strconv"
 	"testing"
@@ -30,6 +31,18 @@ import (
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
+var (
+	// Next offset 256 by convention. Adds 1 for the next offset.
+	selfLink       = vfs.Dirent{Type: linux.DT_LNK, NextOff: 256 + 0 + 1}
+	threadSelfLink = vfs.Dirent{Type: linux.DT_LNK, NextOff: 256 + 1 + 1}
+
+	// /proc/[pid] next offset starts at 256+2 (files above), then adds the
+	// PID, and adds 1 for the next offset.
+	proc1 = vfs.Dirent{Type: linux.DT_DIR, NextOff: 258 + 1 + 1}
+	proc2 = vfs.Dirent{Type: linux.DT_DIR, NextOff: 258 + 2 + 1}
+	proc3 = vfs.Dirent{Type: linux.DT_DIR, NextOff: 258 + 3 + 1}
+)
+
 type testIterDirentsCallback struct {
 	dirents []vfs.Dirent
 }
@@ -59,9 +72,9 @@ func checkTasksStaticFiles(gots []vfs.Dirent) ([]vfs.Dirent, error) {
 		"loadavg":     {Type: linux.DT_REG},
 		"meminfo":     {Type: linux.DT_REG},
 		"mounts":      {Type: linux.DT_LNK},
-		"self":        {Type: linux.DT_LNK},
+		"self":        selfLink,
 		"stat":        {Type: linux.DT_REG},
-		"thread-self": {Type: linux.DT_LNK},
+		"thread-self": threadSelfLink,
 		"version":     {Type: linux.DT_REG},
 	}
 	return checkFiles(gots, wants)
@@ -93,6 +106,9 @@ func checkFiles(gots []vfs.Dirent, wants map[string]vfs.Dirent) ([]vfs.Dirent, e
 		if want.Type != got.Type {
 			return gots, fmt.Errorf("wrong file type, want: %v, got: %v: %+v", want.Type, got.Type, got)
 		}
+		if want.NextOff != 0 && want.NextOff != got.NextOff {
+			return gots, fmt.Errorf("wrong dirent offset, want: %v, got: %v: %+v", want.NextOff, got.NextOff, got)
+		}
 
 		delete(wants, got.Name)
 		gots = append(gots[0:i], gots[i+1:]...)
@@ -154,7 +170,7 @@ func TestTasksEmpty(t *testing.T) {
 		t.Error(err.Error())
 	}
 	if len(cb.dirents) != 0 {
-		t.Error("found more files than expected: %+v", cb.dirents)
+		t.Errorf("found more files than expected: %+v", cb.dirents)
 	}
 }
 
@@ -216,6 +232,11 @@ func TestTasks(t *testing.T) {
 		if !found {
 			t.Errorf("Additional task ID %d listed: %v", pid, tasks)
 		}
+		// Next offset starts at 256+2 ('self' and 'thread-self'), then adds the
+		// PID, and adds 1 for the next offset.
+		if want := int64(256 + 2 + pid + 1); d.NextOff != want {
+			t.Errorf("Wrong dirent offset want: %d got: %d: %+v", want, d.NextOff, d)
+		}
 	}
 
 	// Test lookup.
@@ -246,6 +267,126 @@ func TestTasks(t *testing.T) {
 	}
 }
 
+func TestTasksOffset(t *testing.T) {
+	ctx, vfsObj, root, err := setup()
+	if err != nil {
+		t.Fatalf("Setup failed: %v", err)
+	}
+	defer root.DecRef()
+
+	k := kernel.KernelFromContext(ctx)
+	for i := 0; i < 3; i++ {
+		tc := k.NewThreadGroup(nil, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, k.GlobalInit().Limits())
+		if _, err := createTask(ctx, fmt.Sprintf("name-%d", i), tc); err != nil {
+			t.Fatalf("CreateTask(): %v", err)
+		}
+	}
+
+	for _, tc := range []struct {
+		name   string
+		offset int64
+		wants  map[string]vfs.Dirent
+	}{
+		{
+			name:   "small offset",
+			offset: 100,
+			wants: map[string]vfs.Dirent{
+				"self":        selfLink,
+				"thread-self": threadSelfLink,
+				"1":           proc1,
+				"2":           proc2,
+				"3":           proc3,
+			},
+		},
+		{
+			name:   "offset at start",
+			offset: 256,
+			wants: map[string]vfs.Dirent{
+				"self":        selfLink,
+				"thread-self": threadSelfLink,
+				"1":           proc1,
+				"2":           proc2,
+				"3":           proc3,
+			},
+		},
+		{
+			name:   "skip /proc/self",
+			offset: 257,
+			wants: map[string]vfs.Dirent{
+				"thread-self": threadSelfLink,
+				"1":           proc1,
+				"2":           proc2,
+				"3":           proc3,
+			},
+		},
+		{
+			name:   "skip symlinks",
+			offset: 258,
+			wants: map[string]vfs.Dirent{
+				"1": proc1,
+				"2": proc2,
+				"3": proc3,
+			},
+		},
+		{
+			name:   "skip first process",
+			offset: 260,
+			wants: map[string]vfs.Dirent{
+				"2": proc2,
+				"3": proc3,
+			},
+		},
+		{
+			name:   "last process",
+			offset: 261,
+			wants: map[string]vfs.Dirent{
+				"3": proc3,
+			},
+		},
+		{
+			name:   "after last",
+			offset: 262,
+			wants:  nil,
+		},
+		{
+			name:   "TaskLimit+1",
+			offset: kernel.TasksLimit + 1,
+			wants:  nil,
+		},
+		{
+			name:   "max",
+			offset: math.MaxInt64,
+			wants:  nil,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			fd, err := vfsObj.OpenAt(
+				ctx,
+				auth.CredentialsFromContext(ctx),
+				&vfs.PathOperation{Root: root, Start: root, Path: fspath.Parse("/")},
+				&vfs.OpenOptions{},
+			)
+			if err != nil {
+				t.Fatalf("vfsfs.OpenAt(/) failed: %v", err)
+			}
+			if _, err := fd.Impl().Seek(ctx, tc.offset, linux.SEEK_SET); err != nil {
+				t.Fatalf("Seek(%d, SEEK_SET): %v", tc.offset, err)
+			}
+
+			cb := testIterDirentsCallback{}
+			if err := fd.Impl().IterDirents(ctx, &cb); err != nil {
+				t.Fatalf("IterDirents(): %v", err)
+			}
+			if cb.dirents, err = checkFiles(cb.dirents, tc.wants); err != nil {
+				t.Error(err.Error())
+			}
+			if len(cb.dirents) != 0 {
+				t.Errorf("found more files than expected: %+v", cb.dirents)
+			}
+		})
+	}
+}
+
 func TestTask(t *testing.T) {
 	ctx, vfsObj, root, err := setup()
 	if err != nil {
diff --git a/pkg/sentry/fsimpl/tmpfs/BUILD b/pkg/sentry/fsimpl/tmpfs/BUILD
index a5b285987..82f5c2f41 100644
--- a/pkg/sentry/fsimpl/tmpfs/BUILD
+++ b/pkg/sentry/fsimpl/tmpfs/BUILD
@@ -47,6 +47,7 @@ go_library(
         "//pkg/sentry/usage",
         "//pkg/sentry/usermem",
         "//pkg/sentry/vfs",
+        "//pkg/sync",
         "//pkg/syserror",
     ],
 )
diff --git a/pkg/sentry/fsimpl/tmpfs/regular_file.go b/pkg/sentry/fsimpl/tmpfs/regular_file.go
index f51e247a7..f200e767d 100644
--- a/pkg/sentry/fsimpl/tmpfs/regular_file.go
+++ b/pkg/sentry/fsimpl/tmpfs/regular_file.go
@@ -17,7 +17,6 @@ package tmpfs
 import (
 	"io"
 	"math"
-	"sync"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -30,6 +29,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/usage"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
index 7be6faa5b..701826f90 100644
--- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go
+++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
@@ -26,7 +26,6 @@ package tmpfs
 import (
 	"fmt"
 	"math"
-	"sync"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -34,6 +33,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/pgalloc"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/kernel/BUILD b/pkg/sentry/kernel/BUILD
index 2706927ff..ac85ba0c8 100644
--- a/pkg/sentry/kernel/BUILD
+++ b/pkg/sentry/kernel/BUILD
@@ -35,7 +35,7 @@ go_template_instance(
     out = "seqatomic_taskgoroutineschedinfo_unsafe.go",
     package = "kernel",
     suffix = "TaskGoroutineSchedInfo",
-    template = "//pkg/syncutil:generic_seqatomic",
+    template = "//pkg/sync:generic_seqatomic",
     types = {
         "Value": "TaskGoroutineSchedInfo",
     },
@@ -209,7 +209,7 @@ go_library(
         "//pkg/sentry/usermem",
         "//pkg/state",
         "//pkg/state/statefile",
-        "//pkg/syncutil",
+        "//pkg/sync",
         "//pkg/syserr",
         "//pkg/syserror",
         "//pkg/tcpip",
@@ -241,6 +241,7 @@ go_test(
         "//pkg/sentry/time",
         "//pkg/sentry/usage",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
     ],
 )
diff --git a/pkg/sentry/kernel/abstract_socket_namespace.go b/pkg/sentry/kernel/abstract_socket_namespace.go
index 244655b5c..920fe4329 100644
--- a/pkg/sentry/kernel/abstract_socket_namespace.go
+++ b/pkg/sentry/kernel/abstract_socket_namespace.go
@@ -15,11 +15,11 @@
 package kernel
 
 import (
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/refs"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // +stateify savable
diff --git a/pkg/sentry/kernel/auth/BUILD b/pkg/sentry/kernel/auth/BUILD
index 04c244447..1aa72fa47 100644
--- a/pkg/sentry/kernel/auth/BUILD
+++ b/pkg/sentry/kernel/auth/BUILD
@@ -8,7 +8,7 @@ go_template_instance(
     out = "atomicptr_credentials_unsafe.go",
     package = "auth",
     suffix = "Credentials",
-    template = "//pkg/syncutil:generic_atomicptr",
+    template = "//pkg/sync:generic_atomicptr",
     types = {
         "Value": "Credentials",
     },
@@ -64,6 +64,7 @@ go_library(
         "//pkg/bits",
         "//pkg/log",
         "//pkg/sentry/context",
+        "//pkg/sync",
         "//pkg/syserror",
     ],
 )
diff --git a/pkg/sentry/kernel/auth/user_namespace.go b/pkg/sentry/kernel/auth/user_namespace.go
index af28ccc65..9dd52c860 100644
--- a/pkg/sentry/kernel/auth/user_namespace.go
+++ b/pkg/sentry/kernel/auth/user_namespace.go
@@ -16,8 +16,8 @@ package auth
 
 import (
 	"math"
-	"sync"
 
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/kernel/epoll/BUILD b/pkg/sentry/kernel/epoll/BUILD
index 3361e8b7d..c47f6b6fc 100644
--- a/pkg/sentry/kernel/epoll/BUILD
+++ b/pkg/sentry/kernel/epoll/BUILD
@@ -32,6 +32,7 @@ go_library(
         "//pkg/sentry/fs/anon",
         "//pkg/sentry/fs/fsutil",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/waiter",
     ],
 )
diff --git a/pkg/sentry/kernel/epoll/epoll.go b/pkg/sentry/kernel/epoll/epoll.go
index 9c0a4e1b4..430311cc0 100644
--- a/pkg/sentry/kernel/epoll/epoll.go
+++ b/pkg/sentry/kernel/epoll/epoll.go
@@ -18,7 +18,6 @@ package epoll
 
 import (
 	"fmt"
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/refs"
@@ -27,6 +26,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs/anon"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
 
diff --git a/pkg/sentry/kernel/eventfd/BUILD b/pkg/sentry/kernel/eventfd/BUILD
index e65b961e8..c831fbab2 100644
--- a/pkg/sentry/kernel/eventfd/BUILD
+++ b/pkg/sentry/kernel/eventfd/BUILD
@@ -16,6 +16,7 @@ go_library(
         "//pkg/sentry/fs/anon",
         "//pkg/sentry/fs/fsutil",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
diff --git a/pkg/sentry/kernel/eventfd/eventfd.go b/pkg/sentry/kernel/eventfd/eventfd.go
index 12f0d429b..687690679 100644
--- a/pkg/sentry/kernel/eventfd/eventfd.go
+++ b/pkg/sentry/kernel/eventfd/eventfd.go
@@ -18,7 +18,6 @@ package eventfd
 
 import (
 	"math"
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -28,6 +27,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs/anon"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/kernel/fasync/BUILD b/pkg/sentry/kernel/fasync/BUILD
index 49d81b712..6b36bc63e 100644
--- a/pkg/sentry/kernel/fasync/BUILD
+++ b/pkg/sentry/kernel/fasync/BUILD
@@ -12,6 +12,7 @@ go_library(
         "//pkg/sentry/fs",
         "//pkg/sentry/kernel",
         "//pkg/sentry/kernel/auth",
+        "//pkg/sync",
         "//pkg/waiter",
     ],
 )
diff --git a/pkg/sentry/kernel/fasync/fasync.go b/pkg/sentry/kernel/fasync/fasync.go
index 6b0bb0324..d32c3e90a 100644
--- a/pkg/sentry/kernel/fasync/fasync.go
+++ b/pkg/sentry/kernel/fasync/fasync.go
@@ -16,12 +16,11 @@
 package fasync
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
 
diff --git a/pkg/sentry/kernel/fd_table.go b/pkg/sentry/kernel/fd_table.go
index 11f613a11..cd1501f85 100644
--- a/pkg/sentry/kernel/fd_table.go
+++ b/pkg/sentry/kernel/fd_table.go
@@ -18,7 +18,6 @@ import (
 	"bytes"
 	"fmt"
 	"math"
-	"sync"
 	"sync/atomic"
 	"syscall"
 
@@ -28,6 +27,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/lock"
 	"gvisor.dev/gvisor/pkg/sentry/limits"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // FDFlags define flags for an individual descriptor.
diff --git a/pkg/sentry/kernel/fd_table_test.go b/pkg/sentry/kernel/fd_table_test.go
index 2bcb6216a..eccb7d1e7 100644
--- a/pkg/sentry/kernel/fd_table_test.go
+++ b/pkg/sentry/kernel/fd_table_test.go
@@ -16,7 +16,6 @@ package kernel
 
 import (
 	"runtime"
-	"sync"
 	"testing"
 
 	"gvisor.dev/gvisor/pkg/sentry/context"
@@ -24,6 +23,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/filetest"
 	"gvisor.dev/gvisor/pkg/sentry/limits"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 const (
diff --git a/pkg/sentry/kernel/fs_context.go b/pkg/sentry/kernel/fs_context.go
index ded27d668..2448c1d99 100644
--- a/pkg/sentry/kernel/fs_context.go
+++ b/pkg/sentry/kernel/fs_context.go
@@ -16,10 +16,10 @@ package kernel
 
 import (
 	"fmt"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/refs"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // FSContext contains filesystem context.
diff --git a/pkg/sentry/kernel/futex/BUILD b/pkg/sentry/kernel/futex/BUILD
index 75ec31761..50db443ce 100644
--- a/pkg/sentry/kernel/futex/BUILD
+++ b/pkg/sentry/kernel/futex/BUILD
@@ -9,7 +9,7 @@ go_template_instance(
     out = "atomicptr_bucket_unsafe.go",
     package = "futex",
     suffix = "Bucket",
-    template = "//pkg/syncutil:generic_atomicptr",
+    template = "//pkg/sync:generic_atomicptr",
     types = {
         "Value": "bucket",
     },
@@ -42,6 +42,7 @@ go_library(
         "//pkg/sentry/context",
         "//pkg/sentry/memmap",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
     ],
 )
@@ -51,5 +52,8 @@ go_test(
     size = "small",
     srcs = ["futex_test.go"],
     embed = [":futex"],
-    deps = ["//pkg/sentry/usermem"],
+    deps = [
+        "//pkg/sentry/usermem",
+        "//pkg/sync",
+    ],
 )
diff --git a/pkg/sentry/kernel/futex/futex.go b/pkg/sentry/kernel/futex/futex.go
index 278cc8143..d1931c8f4 100644
--- a/pkg/sentry/kernel/futex/futex.go
+++ b/pkg/sentry/kernel/futex/futex.go
@@ -18,11 +18,10 @@
 package futex
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/kernel/futex/futex_test.go b/pkg/sentry/kernel/futex/futex_test.go
index 65e5d1428..c23126ca5 100644
--- a/pkg/sentry/kernel/futex/futex_test.go
+++ b/pkg/sentry/kernel/futex/futex_test.go
@@ -17,13 +17,13 @@ package futex
 import (
 	"math"
 	"runtime"
-	"sync"
 	"sync/atomic"
 	"syscall"
 	"testing"
 	"unsafe"
 
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // testData implements the Target interface, and allows us to
diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go
index 8653d2f63..c85e97fef 100644
--- a/pkg/sentry/kernel/kernel.go
+++ b/pkg/sentry/kernel/kernel.go
@@ -36,7 +36,6 @@ import (
 	"fmt"
 	"io"
 	"path/filepath"
-	"sync"
 	"sync/atomic"
 	"time"
 
@@ -67,6 +66,7 @@ import (
 	uspb "gvisor.dev/gvisor/pkg/sentry/unimpl/unimplemented_syscall_go_proto"
 	"gvisor.dev/gvisor/pkg/sentry/uniqueid"
 	"gvisor.dev/gvisor/pkg/state"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/tcpip"
 )
 
diff --git a/pkg/sentry/kernel/memevent/BUILD b/pkg/sentry/kernel/memevent/BUILD
index d7a7d1169..7f36252a9 100644
--- a/pkg/sentry/kernel/memevent/BUILD
+++ b/pkg/sentry/kernel/memevent/BUILD
@@ -16,6 +16,7 @@ go_library(
         "//pkg/metric",
         "//pkg/sentry/kernel",
         "//pkg/sentry/usage",
+        "//pkg/sync",
     ],
 )
 
diff --git a/pkg/sentry/kernel/memevent/memory_events.go b/pkg/sentry/kernel/memevent/memory_events.go
index b0d98e7f0..200565bb8 100644
--- a/pkg/sentry/kernel/memevent/memory_events.go
+++ b/pkg/sentry/kernel/memevent/memory_events.go
@@ -17,7 +17,6 @@
 package memevent
 
 import (
-	"sync"
 	"time"
 
 	"gvisor.dev/gvisor/pkg/eventchannel"
@@ -26,6 +25,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	pb "gvisor.dev/gvisor/pkg/sentry/kernel/memevent/memory_events_go_proto"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 var totalTicks = metric.MustCreateNewUint64Metric("/memory_events/ticks", false /*sync*/, "Total number of memory event periods that have elapsed since startup.")
diff --git a/pkg/sentry/kernel/pipe/BUILD b/pkg/sentry/kernel/pipe/BUILD
index 9d34f6d4d..5eeaeff66 100644
--- a/pkg/sentry/kernel/pipe/BUILD
+++ b/pkg/sentry/kernel/pipe/BUILD
@@ -43,6 +43,7 @@ go_library(
         "//pkg/sentry/safemem",
         "//pkg/sentry/usermem",
         "//pkg/sentry/vfs",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
diff --git a/pkg/sentry/kernel/pipe/buffer.go b/pkg/sentry/kernel/pipe/buffer.go
index 95bee2d37..1c0f34269 100644
--- a/pkg/sentry/kernel/pipe/buffer.go
+++ b/pkg/sentry/kernel/pipe/buffer.go
@@ -16,9 +16,9 @@ package pipe
 
 import (
 	"io"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // buffer encapsulates a queueable byte buffer.
diff --git a/pkg/sentry/kernel/pipe/node.go b/pkg/sentry/kernel/pipe/node.go
index 4a19ab7ce..716f589af 100644
--- a/pkg/sentry/kernel/pipe/node.go
+++ b/pkg/sentry/kernel/pipe/node.go
@@ -15,12 +15,11 @@
 package pipe
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/kernel/pipe/pipe.go b/pkg/sentry/kernel/pipe/pipe.go
index 1a1b38f83..e4fd7d420 100644
--- a/pkg/sentry/kernel/pipe/pipe.go
+++ b/pkg/sentry/kernel/pipe/pipe.go
@@ -17,12 +17,12 @@ package pipe
 
 import (
 	"fmt"
-	"sync"
 	"sync/atomic"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/kernel/pipe/pipe_util.go b/pkg/sentry/kernel/pipe/pipe_util.go
index ef9641e6a..8394eb78b 100644
--- a/pkg/sentry/kernel/pipe/pipe_util.go
+++ b/pkg/sentry/kernel/pipe/pipe_util.go
@@ -17,7 +17,6 @@ package pipe
 import (
 	"io"
 	"math"
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -25,6 +24,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
 
diff --git a/pkg/sentry/kernel/pipe/vfs.go b/pkg/sentry/kernel/pipe/vfs.go
index 6416e0dd8..bf7461cbb 100644
--- a/pkg/sentry/kernel/pipe/vfs.go
+++ b/pkg/sentry/kernel/pipe/vfs.go
@@ -15,13 +15,12 @@
 package pipe
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/kernel/semaphore/BUILD b/pkg/sentry/kernel/semaphore/BUILD
index f4c00cd86..13a961594 100644
--- a/pkg/sentry/kernel/semaphore/BUILD
+++ b/pkg/sentry/kernel/semaphore/BUILD
@@ -31,6 +31,7 @@ go_library(
         "//pkg/sentry/fs",
         "//pkg/sentry/kernel/auth",
         "//pkg/sentry/kernel/time",
+        "//pkg/sync",
         "//pkg/syserror",
     ],
 )
diff --git a/pkg/sentry/kernel/semaphore/semaphore.go b/pkg/sentry/kernel/semaphore/semaphore.go
index de9617e9d..18299814e 100644
--- a/pkg/sentry/kernel/semaphore/semaphore.go
+++ b/pkg/sentry/kernel/semaphore/semaphore.go
@@ -17,7 +17,6 @@ package semaphore
 
 import (
 	"fmt"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/log"
@@ -25,6 +24,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/kernel/shm/BUILD b/pkg/sentry/kernel/shm/BUILD
index cd48945e6..7321b22ed 100644
--- a/pkg/sentry/kernel/shm/BUILD
+++ b/pkg/sentry/kernel/shm/BUILD
@@ -24,6 +24,7 @@ go_library(
         "//pkg/sentry/platform",
         "//pkg/sentry/usage",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
     ],
 )
diff --git a/pkg/sentry/kernel/shm/shm.go b/pkg/sentry/kernel/shm/shm.go
index 19034a21e..8ddef7eb8 100644
--- a/pkg/sentry/kernel/shm/shm.go
+++ b/pkg/sentry/kernel/shm/shm.go
@@ -35,7 +35,6 @@ package shm
 
 import (
 	"fmt"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/log"
@@ -49,6 +48,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/kernel/signal_handlers.go b/pkg/sentry/kernel/signal_handlers.go
index a16f3d57f..768fda220 100644
--- a/pkg/sentry/kernel/signal_handlers.go
+++ b/pkg/sentry/kernel/signal_handlers.go
@@ -15,10 +15,9 @@
 package kernel
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // SignalHandlers holds information about signal actions.
diff --git a/pkg/sentry/kernel/signalfd/BUILD b/pkg/sentry/kernel/signalfd/BUILD
index 9f7e19b4d..89e4d84b1 100644
--- a/pkg/sentry/kernel/signalfd/BUILD
+++ b/pkg/sentry/kernel/signalfd/BUILD
@@ -16,6 +16,7 @@ go_library(
         "//pkg/sentry/fs/fsutil",
         "//pkg/sentry/kernel",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
diff --git a/pkg/sentry/kernel/signalfd/signalfd.go b/pkg/sentry/kernel/signalfd/signalfd.go
index 4b08d7d72..28be4a939 100644
--- a/pkg/sentry/kernel/signalfd/signalfd.go
+++ b/pkg/sentry/kernel/signalfd/signalfd.go
@@ -16,8 +16,6 @@
 package signalfd
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/binary"
 	"gvisor.dev/gvisor/pkg/sentry/context"
@@ -26,6 +24,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/kernel/syscalls.go b/pkg/sentry/kernel/syscalls.go
index 2fdee0282..d2d01add4 100644
--- a/pkg/sentry/kernel/syscalls.go
+++ b/pkg/sentry/kernel/syscalls.go
@@ -16,13 +16,13 @@ package kernel
 
 import (
 	"fmt"
-	"sync"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi"
 	"gvisor.dev/gvisor/pkg/bits"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // maxSyscallNum is the highest supported syscall number.
diff --git a/pkg/sentry/kernel/syslog.go b/pkg/sentry/kernel/syslog.go
index 8227ecf1d..4607cde2f 100644
--- a/pkg/sentry/kernel/syslog.go
+++ b/pkg/sentry/kernel/syslog.go
@@ -17,7 +17,8 @@ package kernel
 import (
 	"fmt"
 	"math/rand"
-	"sync"
+
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // syslog represents a sentry-global kernel log.
diff --git a/pkg/sentry/kernel/task.go b/pkg/sentry/kernel/task.go
index d25a7903b..978d66da8 100644
--- a/pkg/sentry/kernel/task.go
+++ b/pkg/sentry/kernel/task.go
@@ -17,7 +17,6 @@ package kernel
 import (
 	gocontext "context"
 	"runtime/trace"
-	"sync"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -37,7 +36,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/uniqueid"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
-	"gvisor.dev/gvisor/pkg/syncutil"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
 
@@ -85,7 +84,7 @@ type Task struct {
 	//
 	// gosched is protected by goschedSeq. gosched is owned by the task
 	// goroutine.
-	goschedSeq syncutil.SeqCount `state:"nosave"`
+	goschedSeq sync.SeqCount `state:"nosave"`
 	gosched    TaskGoroutineSchedInfo
 
 	// yieldCount is the number of times the task goroutine has called
diff --git a/pkg/sentry/kernel/thread_group.go b/pkg/sentry/kernel/thread_group.go
index c0197a563..768e958d2 100644
--- a/pkg/sentry/kernel/thread_group.go
+++ b/pkg/sentry/kernel/thread_group.go
@@ -15,7 +15,6 @@
 package kernel
 
 import (
-	"sync"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -25,6 +24,7 @@ import (
 	ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
 	"gvisor.dev/gvisor/pkg/sentry/limits"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/kernel/threads.go b/pkg/sentry/kernel/threads.go
index 8267929a6..bf2dabb6e 100644
--- a/pkg/sentry/kernel/threads.go
+++ b/pkg/sentry/kernel/threads.go
@@ -16,9 +16,9 @@ package kernel
 
 import (
 	"fmt"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
 
diff --git a/pkg/sentry/kernel/time/BUILD b/pkg/sentry/kernel/time/BUILD
index 31847e1df..4e4de0512 100644
--- a/pkg/sentry/kernel/time/BUILD
+++ b/pkg/sentry/kernel/time/BUILD
@@ -13,6 +13,7 @@ go_library(
     deps = [
         "//pkg/abi/linux",
         "//pkg/sentry/context",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
diff --git a/pkg/sentry/kernel/time/time.go b/pkg/sentry/kernel/time/time.go
index 107394183..706de83ef 100644
--- a/pkg/sentry/kernel/time/time.go
+++ b/pkg/sentry/kernel/time/time.go
@@ -19,10 +19,10 @@ package time
 import (
 	"fmt"
 	"math"
-	"sync"
 	"time"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/kernel/timekeeper.go b/pkg/sentry/kernel/timekeeper.go
index 76417342a..dc99301de 100644
--- a/pkg/sentry/kernel/timekeeper.go
+++ b/pkg/sentry/kernel/timekeeper.go
@@ -16,7 +16,6 @@ package kernel
 
 import (
 	"fmt"
-	"sync"
 	"time"
 
 	"gvisor.dev/gvisor/pkg/log"
@@ -24,6 +23,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/pgalloc"
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	sentrytime "gvisor.dev/gvisor/pkg/sentry/time"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // Timekeeper manages all of the kernel clocks.
diff --git a/pkg/sentry/kernel/tty.go b/pkg/sentry/kernel/tty.go
index 048de26dc..464d2306a 100644
--- a/pkg/sentry/kernel/tty.go
+++ b/pkg/sentry/kernel/tty.go
@@ -14,7 +14,7 @@
 
 package kernel
 
-import "sync"
+import "gvisor.dev/gvisor/pkg/sync"
 
 // TTY defines the relationship between a thread group and its controlling
 // terminal.
diff --git a/pkg/sentry/kernel/uts_namespace.go b/pkg/sentry/kernel/uts_namespace.go
index 0a563e715..8ccf04bd1 100644
--- a/pkg/sentry/kernel/uts_namespace.go
+++ b/pkg/sentry/kernel/uts_namespace.go
@@ -15,9 +15,8 @@
 package kernel
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // UTSNamespace represents a UTS namespace, a holder of two system identifiers:
diff --git a/pkg/sentry/limits/BUILD b/pkg/sentry/limits/BUILD
index 156e67bf8..9fa841e8b 100644
--- a/pkg/sentry/limits/BUILD
+++ b/pkg/sentry/limits/BUILD
@@ -15,6 +15,7 @@ go_library(
     deps = [
         "//pkg/abi/linux",
         "//pkg/sentry/context",
+        "//pkg/sync",
     ],
 )
 
diff --git a/pkg/sentry/limits/limits.go b/pkg/sentry/limits/limits.go
index b6c22656b..31b9e9ff6 100644
--- a/pkg/sentry/limits/limits.go
+++ b/pkg/sentry/limits/limits.go
@@ -16,8 +16,9 @@
 package limits
 
 import (
-	"sync"
 	"syscall"
+
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // LimitType defines a type of resource limit.
diff --git a/pkg/sentry/mm/BUILD b/pkg/sentry/mm/BUILD
index 839931f67..83e248431 100644
--- a/pkg/sentry/mm/BUILD
+++ b/pkg/sentry/mm/BUILD
@@ -118,7 +118,7 @@ go_library(
         "//pkg/sentry/safemem",
         "//pkg/sentry/usage",
         "//pkg/sentry/usermem",
-        "//pkg/syncutil",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/tcpip/buffer",
     ],
diff --git a/pkg/sentry/mm/aio_context.go b/pkg/sentry/mm/aio_context.go
index 1b746d030..4b48866ad 100644
--- a/pkg/sentry/mm/aio_context.go
+++ b/pkg/sentry/mm/aio_context.go
@@ -15,8 +15,6 @@
 package mm
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/refs"
 	"gvisor.dev/gvisor/pkg/sentry/context"
@@ -25,6 +23,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/mm/mm.go b/pkg/sentry/mm/mm.go
index 58a5c186d..fa86ebced 100644
--- a/pkg/sentry/mm/mm.go
+++ b/pkg/sentry/mm/mm.go
@@ -35,8 +35,6 @@
 package mm
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
@@ -44,7 +42,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
-	"gvisor.dev/gvisor/pkg/syncutil"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // MemoryManager implements a virtual address space.
@@ -82,7 +80,7 @@ type MemoryManager struct {
 	users int32
 
 	// mappingMu is analogous to Linux's struct mm_struct::mmap_sem.
-	mappingMu syncutil.DowngradableRWMutex `state:"nosave"`
+	mappingMu sync.DowngradableRWMutex `state:"nosave"`
 
 	// vmas stores virtual memory areas. Since vmas are stored by value,
 	// clients should usually use vmaIterator.ValuePtr() instead of
@@ -125,7 +123,7 @@ type MemoryManager struct {
 
 	// activeMu is loosely analogous to Linux's struct
 	// mm_struct::page_table_lock.
-	activeMu syncutil.DowngradableRWMutex `state:"nosave"`
+	activeMu sync.DowngradableRWMutex `state:"nosave"`
 
 	// pmas stores platform mapping areas used to implement vmas. Since pmas
 	// are stored by value, clients should usually use pmaIterator.ValuePtr()
diff --git a/pkg/sentry/pgalloc/BUILD b/pkg/sentry/pgalloc/BUILD
index f404107af..a9a2642c5 100644
--- a/pkg/sentry/pgalloc/BUILD
+++ b/pkg/sentry/pgalloc/BUILD
@@ -73,6 +73,7 @@ go_library(
         "//pkg/sentry/usage",
         "//pkg/sentry/usermem",
         "//pkg/state",
+        "//pkg/sync",
         "//pkg/syserror",
     ],
 )
diff --git a/pkg/sentry/pgalloc/pgalloc.go b/pkg/sentry/pgalloc/pgalloc.go
index f7f7298c4..c99e023d9 100644
--- a/pkg/sentry/pgalloc/pgalloc.go
+++ b/pkg/sentry/pgalloc/pgalloc.go
@@ -25,7 +25,6 @@ import (
 	"fmt"
 	"math"
 	"os"
-	"sync"
 	"sync/atomic"
 	"syscall"
 	"time"
@@ -37,6 +36,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/platform/interrupt/BUILD b/pkg/sentry/platform/interrupt/BUILD
index b6d008dbe..85e882df9 100644
--- a/pkg/sentry/platform/interrupt/BUILD
+++ b/pkg/sentry/platform/interrupt/BUILD
@@ -10,6 +10,7 @@ go_library(
     ],
     importpath = "gvisor.dev/gvisor/pkg/sentry/platform/interrupt",
     visibility = ["//pkg/sentry:internal"],
+    deps = ["//pkg/sync"],
 )
 
 go_test(
diff --git a/pkg/sentry/platform/interrupt/interrupt.go b/pkg/sentry/platform/interrupt/interrupt.go
index a4651f500..57be41647 100644
--- a/pkg/sentry/platform/interrupt/interrupt.go
+++ b/pkg/sentry/platform/interrupt/interrupt.go
@@ -17,7 +17,8 @@ package interrupt
 
 import (
 	"fmt"
-	"sync"
+
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // Receiver receives interrupt notifications from a Forwarder.
diff --git a/pkg/sentry/platform/kvm/BUILD b/pkg/sentry/platform/kvm/BUILD
index f3afd98da..6a358d1d4 100644
--- a/pkg/sentry/platform/kvm/BUILD
+++ b/pkg/sentry/platform/kvm/BUILD
@@ -55,6 +55,7 @@ go_library(
         "//pkg/sentry/platform/safecopy",
         "//pkg/sentry/time",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
     ],
 )
 
diff --git a/pkg/sentry/platform/kvm/address_space.go b/pkg/sentry/platform/kvm/address_space.go
index ea8b9632e..a25f3c449 100644
--- a/pkg/sentry/platform/kvm/address_space.go
+++ b/pkg/sentry/platform/kvm/address_space.go
@@ -15,13 +15,13 @@
 package kvm
 
 import (
-	"sync"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/atomicbitops"
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // dirtySet tracks vCPUs for invalidation.
diff --git a/pkg/sentry/platform/kvm/bluepill_arm64_unsafe.go b/pkg/sentry/platform/kvm/bluepill_arm64_unsafe.go
index e5fac0d6a..2f02c03cf 100644
--- a/pkg/sentry/platform/kvm/bluepill_arm64_unsafe.go
+++ b/pkg/sentry/platform/kvm/bluepill_arm64_unsafe.go
@@ -17,8 +17,6 @@
 package kvm
 
 import (
-	"unsafe"
-
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 )
 
diff --git a/pkg/sentry/platform/kvm/kvm.go b/pkg/sentry/platform/kvm/kvm.go
index f2c2c059e..a7850faed 100644
--- a/pkg/sentry/platform/kvm/kvm.go
+++ b/pkg/sentry/platform/kvm/kvm.go
@@ -18,13 +18,13 @@ package kvm
 import (
 	"fmt"
 	"os"
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0"
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // KVM represents a lightweight VM context.
diff --git a/pkg/sentry/platform/kvm/machine.go b/pkg/sentry/platform/kvm/machine.go
index 7d02ebf19..e6d912168 100644
--- a/pkg/sentry/platform/kvm/machine.go
+++ b/pkg/sentry/platform/kvm/machine.go
@@ -17,7 +17,6 @@ package kvm
 import (
 	"fmt"
 	"runtime"
-	"sync"
 	"sync/atomic"
 	"syscall"
 
@@ -27,6 +26,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0"
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // machine contains state associated with the VM as a whole.
diff --git a/pkg/sentry/platform/ptrace/BUILD b/pkg/sentry/platform/ptrace/BUILD
index 0df8cfa0f..cd13390c3 100644
--- a/pkg/sentry/platform/ptrace/BUILD
+++ b/pkg/sentry/platform/ptrace/BUILD
@@ -33,6 +33,7 @@ go_library(
         "//pkg/sentry/platform/interrupt",
         "//pkg/sentry/platform/safecopy",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "@org_golang_x_sys//unix:go_default_library",
     ],
 )
diff --git a/pkg/sentry/platform/ptrace/ptrace.go b/pkg/sentry/platform/ptrace/ptrace.go
index 7b120a15d..bb0e03880 100644
--- a/pkg/sentry/platform/ptrace/ptrace.go
+++ b/pkg/sentry/platform/ptrace/ptrace.go
@@ -46,13 +46,13 @@ package ptrace
 
 import (
 	"os"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/pkg/sentry/platform/interrupt"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 var (
diff --git a/pkg/sentry/platform/ptrace/subprocess.go b/pkg/sentry/platform/ptrace/subprocess.go
index 20244fd95..15dc46a5b 100644
--- a/pkg/sentry/platform/ptrace/subprocess.go
+++ b/pkg/sentry/platform/ptrace/subprocess.go
@@ -18,7 +18,6 @@ import (
 	"fmt"
 	"os"
 	"runtime"
-	"sync"
 	"syscall"
 
 	"golang.org/x/sys/unix"
@@ -27,6 +26,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // Linux kernel errnos which "should never be seen by user programs", but will
diff --git a/pkg/sentry/platform/ptrace/subprocess_linux_unsafe.go b/pkg/sentry/platform/ptrace/subprocess_linux_unsafe.go
index 2e6fbe488..245b20722 100644
--- a/pkg/sentry/platform/ptrace/subprocess_linux_unsafe.go
+++ b/pkg/sentry/platform/ptrace/subprocess_linux_unsafe.go
@@ -18,7 +18,6 @@
 package ptrace
 
 import (
-	"sync"
 	"sync/atomic"
 	"syscall"
 	"unsafe"
@@ -26,6 +25,7 @@ import (
 	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/hostcpu"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // maskPool contains reusable CPU masks for setting affinity. Unfortunately,
diff --git a/pkg/sentry/platform/ring0/defs.go b/pkg/sentry/platform/ring0/defs.go
index 3f094c2a7..86fd5ed58 100644
--- a/pkg/sentry/platform/ring0/defs.go
+++ b/pkg/sentry/platform/ring0/defs.go
@@ -17,7 +17,7 @@ package ring0
 import (
 	"syscall"
 
-	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
 )
 
 // Kernel is a global kernel object.
diff --git a/pkg/sentry/platform/ring0/defs_amd64.go b/pkg/sentry/platform/ring0/defs_amd64.go
index 10dbd381f..9dae0dccb 100644
--- a/pkg/sentry/platform/ring0/defs_amd64.go
+++ b/pkg/sentry/platform/ring0/defs_amd64.go
@@ -18,6 +18,7 @@ package ring0
 
 import (
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
+	"gvisor.dev/gvisor/pkg/sentry/usermem"
 )
 
 var (
diff --git a/pkg/sentry/platform/ring0/defs_arm64.go b/pkg/sentry/platform/ring0/defs_arm64.go
index dc0eeec01..a850ce6cf 100644
--- a/pkg/sentry/platform/ring0/defs_arm64.go
+++ b/pkg/sentry/platform/ring0/defs_arm64.go
@@ -18,6 +18,7 @@ package ring0
 
 import (
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
+	"gvisor.dev/gvisor/pkg/sentry/usermem"
 )
 
 var (
diff --git a/pkg/sentry/platform/ring0/entry_arm64.s b/pkg/sentry/platform/ring0/entry_arm64.s
index 813ef9822..64e9c0845 100644
--- a/pkg/sentry/platform/ring0/entry_arm64.s
+++ b/pkg/sentry/platform/ring0/entry_arm64.s
@@ -357,6 +357,73 @@ TEXT ·Current(SB),NOSPLIT,$0-8
 #define STACK_FRAME_SIZE 16
 
 TEXT ·kernelExitToEl0(SB),NOSPLIT,$0
+	// Step1, save sentry context into memory.
+	REGISTERS_SAVE(RSV_REG, CPU_REGISTERS)
+	MOVD RSV_REG_APP, CPU_REGISTERS+PTRACE_R9(RSV_REG)
+
+	WORD $0xd5384003    //    MRS SPSR_EL1, R3
+	MOVD R3, CPU_REGISTERS+PTRACE_PSTATE(RSV_REG)
+	MOVD R30, CPU_REGISTERS+PTRACE_PC(RSV_REG)
+	MOVD RSP, R3
+	MOVD R3, CPU_REGISTERS+PTRACE_SP(RSV_REG)
+
+	MOVD CPU_REGISTERS+PTRACE_R3(RSV_REG), R3
+
+	// Step2, save SP_EL1, PSTATE into kernel temporary stack.
+	// switch to temporary stack.
+	LOAD_KERNEL_STACK(RSV_REG)
+	WORD $0xd538d092    //MRS   TPIDR_EL1, R18
+
+	SUB $STACK_FRAME_SIZE, RSP, RSP
+	MOVD CPU_REGISTERS+PTRACE_SP(RSV_REG), R11
+	MOVD CPU_REGISTERS+PTRACE_PSTATE(RSV_REG), R12
+	STP (R11, R12), 16*0(RSP)
+
+	MOVD CPU_REGISTERS+PTRACE_R11(RSV_REG), R11
+	MOVD CPU_REGISTERS+PTRACE_R12(RSV_REG), R12
+
+	// Step3, test user pagetable.
+	// If user pagetable is empty, trapped in el1_ia.
+	WORD $0xd538d092    //MRS   TPIDR_EL1, R18
+	SWITCH_TO_APP_PAGETABLE(RSV_REG)
+	WORD $0xd538d092    //MRS   TPIDR_EL1, R18
+	SWITCH_TO_KVM_PAGETABLE(RSV_REG)
+	WORD $0xd538d092    //MRS   TPIDR_EL1, R18
+
+	// If pagetable is not empty, recovery kernel temporary stack.
+	ADD $STACK_FRAME_SIZE, RSP, RSP
+
+	// Step4, load app context pointer.
+	MOVD CPU_APP_ADDR(RSV_REG), RSV_REG_APP
+
+	// Step5, prepare the environment for container application.
+	// set sp_el0.
+	MOVD PTRACE_SP(RSV_REG_APP), R1
+	WORD $0xd5184101        //MSR R1, SP_EL0
+	// set pc.
+	MOVD PTRACE_PC(RSV_REG_APP), R1
+	MSR R1, ELR_EL1
+	// set pstate.
+	MOVD PTRACE_PSTATE(RSV_REG_APP), R1
+	WORD $0xd5184001  //MSR R1, SPSR_EL1
+
+	// RSV_REG & RSV_REG_APP will be loaded at the end.
+	REGISTERS_LOAD(RSV_REG_APP, 0)
+
+	// switch to user pagetable.
+	MOVD PTRACE_R18(RSV_REG_APP), RSV_REG
+	MOVD PTRACE_R9(RSV_REG_APP), RSV_REG_APP
+
+	SUB $STACK_FRAME_SIZE, RSP, RSP
+	STP (RSV_REG, RSV_REG_APP), 16*0(RSP)
+
+	WORD $0xd538d092    //MRS   TPIDR_EL1, R18
+
+	SWITCH_TO_APP_PAGETABLE(RSV_REG)
+
+	LDP 16*0(RSP), (RSV_REG, RSV_REG_APP)
+	ADD $STACK_FRAME_SIZE, RSP, RSP
+
 	ERET()
 
 TEXT ·kernelExitToEl1(SB),NOSPLIT,$0
diff --git a/pkg/sentry/platform/ring0/pagetables/BUILD b/pkg/sentry/platform/ring0/pagetables/BUILD
index e2e15ba5c..387a7f6c3 100644
--- a/pkg/sentry/platform/ring0/pagetables/BUILD
+++ b/pkg/sentry/platform/ring0/pagetables/BUILD
@@ -96,7 +96,10 @@ go_library(
         "//pkg/sentry/platform/kvm:__subpackages__",
         "//pkg/sentry/platform/ring0:__subpackages__",
     ],
-    deps = ["//pkg/sentry/usermem"],
+    deps = [
+        "//pkg/sentry/usermem",
+        "//pkg/sync",
+    ],
 )
 
 go_test(
diff --git a/pkg/sentry/platform/ring0/pagetables/pcids_x86.go b/pkg/sentry/platform/ring0/pagetables/pcids_x86.go
index 0f029f25d..e199bae18 100644
--- a/pkg/sentry/platform/ring0/pagetables/pcids_x86.go
+++ b/pkg/sentry/platform/ring0/pagetables/pcids_x86.go
@@ -17,7 +17,7 @@
 package pagetables
 
 import (
-	"sync"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // limitPCID is the number of valid PCIDs.
diff --git a/pkg/sentry/socket/control/control.go b/pkg/sentry/socket/control/control.go
index af1a4e95f..4301b697c 100644
--- a/pkg/sentry/socket/control/control.go
+++ b/pkg/sentry/socket/control/control.go
@@ -471,6 +471,9 @@ func Parse(t *kernel.Task, socketOrEndpoint interface{}, buf []byte) (socket.Con
 		case linux.SOL_IP:
 			switch h.Type {
 			case linux.IP_TOS:
+				if length < linux.SizeOfControlMessageTOS {
+					return socket.ControlMessages{}, syserror.EINVAL
+				}
 				cmsgs.IP.HasTOS = true
 				binary.Unmarshal(buf[i:i+linux.SizeOfControlMessageTOS], usermem.ByteOrder, &cmsgs.IP.TOS)
 				i += AlignUp(length, width)
@@ -481,6 +484,9 @@ func Parse(t *kernel.Task, socketOrEndpoint interface{}, buf []byte) (socket.Con
 		case linux.SOL_IPV6:
 			switch h.Type {
 			case linux.IPV6_TCLASS:
+				if length < linux.SizeOfControlMessageTClass {
+					return socket.ControlMessages{}, syserror.EINVAL
+				}
 				cmsgs.IP.HasTClass = true
 				binary.Unmarshal(buf[i:i+linux.SizeOfControlMessageTClass], usermem.ByteOrder, &cmsgs.IP.TClass)
 				i += AlignUp(length, width)
diff --git a/pkg/sentry/socket/netfilter/netfilter.go b/pkg/sentry/socket/netfilter/netfilter.go
index 175466f19..09a3276c7 100644
--- a/pkg/sentry/socket/netfilter/netfilter.go
+++ b/pkg/sentry/socket/netfilter/netfilter.go
@@ -368,9 +368,22 @@ func SetEntries(stack *stack.Stack, optVal []byte) *syserr.Error {
 		}
 	}
 
+	// TODO(gvisor.dev/issue/170): Support other chains.
+	// Since we only support modifying the INPUT chain right now, make sure
+	// all other chains point to ACCEPT rules.
+	for hook, ruleIdx := range table.BuiltinChains {
+		if hook != iptables.Input {
+			if _, ok := table.Rules[ruleIdx].Target.(iptables.UnconditionalAcceptTarget); !ok {
+				log.Warningf("Hook %d is unsupported.", hook)
+				return syserr.ErrInvalidArgument
+			}
+		}
+	}
+
 	// TODO(gvisor.dev/issue/170): Check the following conditions:
 	// - There are no loops.
 	// - There are no chains without an unconditional final rule.
+	// - There are no chains without an unconditional underflow rule.
 
 	ipt := stack.IPTables()
 	table.SetMetadata(metadata{
@@ -488,7 +501,7 @@ func hookFromLinux(hook int) iptables.Hook {
 	case linux.NF_INET_POST_ROUTING:
 		return iptables.Postrouting
 	}
-	panic(fmt.Sprintf("Unknown hook %d does not correspond to a builtin chain"))
+	panic(fmt.Sprintf("Unknown hook %d does not correspond to a builtin chain", hook))
 }
 
 // printReplace prints information about the struct ipt_replace in optVal. It
diff --git a/pkg/sentry/socket/netlink/BUILD b/pkg/sentry/socket/netlink/BUILD
index 79589e3c8..103933144 100644
--- a/pkg/sentry/socket/netlink/BUILD
+++ b/pkg/sentry/socket/netlink/BUILD
@@ -22,12 +22,12 @@ go_library(
         "//pkg/sentry/kernel",
         "//pkg/sentry/kernel/auth",
         "//pkg/sentry/kernel/time",
-        "//pkg/sentry/safemem",
         "//pkg/sentry/socket",
         "//pkg/sentry/socket/netlink/port",
         "//pkg/sentry/socket/unix",
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserr",
         "//pkg/syserror",
         "//pkg/tcpip",
diff --git a/pkg/sentry/socket/netlink/port/BUILD b/pkg/sentry/socket/netlink/port/BUILD
index 463544c1a..2d9f4ba9b 100644
--- a/pkg/sentry/socket/netlink/port/BUILD
+++ b/pkg/sentry/socket/netlink/port/BUILD
@@ -8,6 +8,7 @@ go_library(
     srcs = ["port.go"],
     importpath = "gvisor.dev/gvisor/pkg/sentry/socket/netlink/port",
     visibility = ["//pkg/sentry:internal"],
+    deps = ["//pkg/sync"],
 )
 
 go_test(
diff --git a/pkg/sentry/socket/netlink/port/port.go b/pkg/sentry/socket/netlink/port/port.go
index e9d3275b1..2cd3afc22 100644
--- a/pkg/sentry/socket/netlink/port/port.go
+++ b/pkg/sentry/socket/netlink/port/port.go
@@ -24,7 +24,8 @@ import (
 	"fmt"
 	"math"
 	"math/rand"
-	"sync"
+
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // maxPorts is a sanity limit on the maximum number of ports to allocate per
diff --git a/pkg/sentry/socket/netlink/socket.go b/pkg/sentry/socket/netlink/socket.go
index 4a1b87a9a..cea56f4ed 100644
--- a/pkg/sentry/socket/netlink/socket.go
+++ b/pkg/sentry/socket/netlink/socket.go
@@ -17,7 +17,6 @@ package netlink
 
 import (
 	"math"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/binary"
@@ -29,12 +28,12 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
-	"gvisor.dev/gvisor/pkg/sentry/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/socket"
 	"gvisor.dev/gvisor/pkg/sentry/socket/netlink/port"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix"
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserr"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/tcpip"
@@ -500,29 +499,29 @@ func (s *Socket) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags int, have
 	trunc := flags&linux.MSG_TRUNC != 0
 
 	r := unix.EndpointReader{
+		Ctx:      t,
 		Endpoint: s.ep,
 		Peek:     flags&linux.MSG_PEEK != 0,
 	}
 
+	doRead := func() (int64, error) {
+		return dst.CopyOutFrom(t, &r)
+	}
+
 	// If MSG_TRUNC is set with a zero byte destination then we still need
 	// to read the message and discard it, or in the case where MSG_PEEK is
 	// set, leave it be. In both cases the full message length must be
-	// returned. However, the memory manager for the destination will not read
-	// the endpoint if the destination is zero length.
-	//
-	// In order for the endpoint to be read when the destination size is zero,
-	// we must cause a read of the endpoint by using a separate fake zero
-	// length block sequence and calling the EndpointReader directly.
+	// returned.
 	if trunc && dst.Addrs.NumBytes() == 0 {
-		// Perform a read to a zero byte block sequence. We can ignore the
-		// original destination since it was zero bytes. The length returned by
-		// ReadToBlocks is ignored and we return the full message length to comply
-		// with MSG_TRUNC.
-		_, err := r.ReadToBlocks(safemem.BlockSeqOf(safemem.BlockFromSafeSlice(make([]byte, 0))))
-		return int(r.MsgSize), linux.MSG_TRUNC, from, fromLen, socket.ControlMessages{}, syserr.FromError(err)
+		doRead = func() (int64, error) {
+			err := r.Truncate()
+			// Always return zero for bytes read since the destination size is
+			// zero.
+			return 0, err
+		}
 	}
 
-	if n, err := dst.CopyOutFrom(t, &r); err != syserror.ErrWouldBlock || flags&linux.MSG_DONTWAIT != 0 {
+	if n, err := doRead(); err != syserror.ErrWouldBlock || flags&linux.MSG_DONTWAIT != 0 {
 		var mflags int
 		if n < int64(r.MsgSize) {
 			mflags |= linux.MSG_TRUNC
@@ -540,7 +539,7 @@ func (s *Socket) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags int, have
 	defer s.EventUnregister(&e)
 
 	for {
-		if n, err := dst.CopyOutFrom(t, &r); err != syserror.ErrWouldBlock {
+		if n, err := doRead(); err != syserror.ErrWouldBlock {
 			var mflags int
 			if n < int64(r.MsgSize) {
 				mflags |= linux.MSG_TRUNC
diff --git a/pkg/sentry/socket/netstack/BUILD b/pkg/sentry/socket/netstack/BUILD
index e414d8055..f78784569 100644
--- a/pkg/sentry/socket/netstack/BUILD
+++ b/pkg/sentry/socket/netstack/BUILD
@@ -34,6 +34,7 @@ go_library(
         "//pkg/sentry/socket/netfilter",
         "//pkg/sentry/unimpl",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserr",
         "//pkg/syserror",
         "//pkg/tcpip",
diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go
index 85d5b7424..f7b069eed 100644
--- a/pkg/sentry/socket/netstack/netstack.go
+++ b/pkg/sentry/socket/netstack/netstack.go
@@ -29,7 +29,6 @@ import (
 	"io"
 	"math"
 	"reflect"
-	"sync"
 	"syscall"
 	"time"
 
@@ -49,6 +48,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/socket/netfilter"
 	"gvisor.dev/gvisor/pkg/sentry/unimpl"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserr"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/tcpip"
@@ -222,17 +222,25 @@ type commonEndpoint interface {
 	// transport.Endpoint.SetSockOpt.
 	SetSockOpt(interface{}) *tcpip.Error
 
+	// SetSockOptBool implements tcpip.Endpoint.SetSockOptBool and
+	// transport.Endpoint.SetSockOptBool.
+	SetSockOptBool(opt tcpip.SockOptBool, v bool) *tcpip.Error
+
 	// SetSockOptInt implements tcpip.Endpoint.SetSockOptInt and
 	// transport.Endpoint.SetSockOptInt.
-	SetSockOptInt(opt tcpip.SockOpt, v int) *tcpip.Error
+	SetSockOptInt(opt tcpip.SockOptInt, v int) *tcpip.Error
 
 	// GetSockOpt implements tcpip.Endpoint.GetSockOpt and
 	// transport.Endpoint.GetSockOpt.
 	GetSockOpt(interface{}) *tcpip.Error
 
+	// GetSockOptBool implements tcpip.Endpoint.GetSockOptBool and
+	// transport.Endpoint.GetSockOpt.
+	GetSockOptBool(opt tcpip.SockOptBool) (bool, *tcpip.Error)
+
 	// GetSockOptInt implements tcpip.Endpoint.GetSockOptInt and
 	// transport.Endpoint.GetSockOpt.
-	GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error)
+	GetSockOptInt(opt tcpip.SockOptInt) (int, *tcpip.Error)
 }
 
 // SocketOperations encapsulates all the state needed to represent a network stack
@@ -985,13 +993,23 @@ func getSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, family
 		if err := ep.GetSockOpt(&v); err != nil {
 			return nil, syserr.TranslateNetstackError(err)
 		}
-		if len(v) == 0 {
+		if v == 0 {
 			return []byte{}, nil
 		}
 		if outLen < linux.IFNAMSIZ {
 			return nil, syserr.ErrInvalidArgument
 		}
-		return append([]byte(v), 0), nil
+		s := t.NetworkContext()
+		if s == nil {
+			return nil, syserr.ErrNoDevice
+		}
+		nic, ok := s.Interfaces()[int32(v)]
+		if !ok {
+			// The NICID no longer indicates a valid interface, probably because that
+			// interface was removed.
+			return nil, syserr.ErrUnknownDevice
+		}
+		return append([]byte(nic.Name), 0), nil
 
 	case linux.SO_BROADCAST:
 		if outLen < sizeOfInt32 {
@@ -1221,12 +1239,15 @@ func getSockOptIPv6(t *kernel.Task, ep commonEndpoint, name, outLen int) (interf
 			return nil, syserr.ErrInvalidArgument
 		}
 
-		var v tcpip.V6OnlyOption
-		if err := ep.GetSockOpt(&v); err != nil {
+		v, err := ep.GetSockOptBool(tcpip.V6OnlyOption)
+		if err != nil {
 			return nil, syserr.TranslateNetstackError(err)
 		}
-
-		return int32(v), nil
+		var o uint32
+		if v {
+			o = 1
+		}
+		return int32(o), nil
 
 	case linux.IPV6_PATHMTU:
 		t.Kernel().EmitUnimplementedEvent(t)
@@ -1455,7 +1476,20 @@ func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name i
 		if n == -1 {
 			n = len(optVal)
 		}
-		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.BindToDeviceOption(optVal[:n])))
+		name := string(optVal[:n])
+		if name == "" {
+			return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.BindToDeviceOption(0)))
+		}
+		s := t.NetworkContext()
+		if s == nil {
+			return syserr.ErrNoDevice
+		}
+		for nicID, nic := range s.Interfaces() {
+			if nic.Name == name {
+				return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.BindToDeviceOption(nicID)))
+			}
+		}
+		return syserr.ErrUnknownDevice
 
 	case linux.SO_BROADCAST:
 		if len(optVal) < sizeOfInt32 {
@@ -1649,7 +1683,7 @@ func setSockOptIPv6(t *kernel.Task, ep commonEndpoint, name int, optVal []byte)
 		}
 
 		v := usermem.ByteOrder.Uint32(optVal)
-		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.V6OnlyOption(v)))
+		return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.V6OnlyOption, v != 0))
 
 	case linux.IPV6_ADD_MEMBERSHIP,
 		linux.IPV6_DROP_MEMBERSHIP,
diff --git a/pkg/sentry/socket/rpcinet/conn/BUILD b/pkg/sentry/socket/rpcinet/conn/BUILD
index 23eadcb1b..b2677c659 100644
--- a/pkg/sentry/socket/rpcinet/conn/BUILD
+++ b/pkg/sentry/socket/rpcinet/conn/BUILD
@@ -10,6 +10,7 @@ go_library(
     deps = [
         "//pkg/binary",
         "//pkg/sentry/socket/rpcinet:syscall_rpc_go_proto",
+        "//pkg/sync",
         "//pkg/syserr",
         "//pkg/unet",
         "@com_github_golang_protobuf//proto:go_default_library",
diff --git a/pkg/sentry/socket/rpcinet/conn/conn.go b/pkg/sentry/socket/rpcinet/conn/conn.go
index 356adad99..02f39c767 100644
--- a/pkg/sentry/socket/rpcinet/conn/conn.go
+++ b/pkg/sentry/socket/rpcinet/conn/conn.go
@@ -17,12 +17,12 @@ package conn
 
 import (
 	"fmt"
-	"sync"
 	"sync/atomic"
 	"syscall"
 
 	"github.com/golang/protobuf/proto"
 	"gvisor.dev/gvisor/pkg/binary"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserr"
 	"gvisor.dev/gvisor/pkg/unet"
 
diff --git a/pkg/sentry/socket/rpcinet/notifier/BUILD b/pkg/sentry/socket/rpcinet/notifier/BUILD
index a3585e10d..a5954f22b 100644
--- a/pkg/sentry/socket/rpcinet/notifier/BUILD
+++ b/pkg/sentry/socket/rpcinet/notifier/BUILD
@@ -10,6 +10,7 @@ go_library(
     deps = [
         "//pkg/sentry/socket/rpcinet:syscall_rpc_go_proto",
         "//pkg/sentry/socket/rpcinet/conn",
+        "//pkg/sync",
         "//pkg/waiter",
         "@org_golang_x_sys//unix:go_default_library",
     ],
diff --git a/pkg/sentry/socket/rpcinet/notifier/notifier.go b/pkg/sentry/socket/rpcinet/notifier/notifier.go
index 7efe4301f..82b75d6dd 100644
--- a/pkg/sentry/socket/rpcinet/notifier/notifier.go
+++ b/pkg/sentry/socket/rpcinet/notifier/notifier.go
@@ -17,12 +17,12 @@ package notifier
 
 import (
 	"fmt"
-	"sync"
 	"syscall"
 
 	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/sentry/socket/rpcinet/conn"
 	pb "gvisor.dev/gvisor/pkg/sentry/socket/rpcinet/syscall_rpc_go_proto"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
 
diff --git a/pkg/sentry/socket/unix/io.go b/pkg/sentry/socket/unix/io.go
index 2ec1a662d..2447f24ef 100644
--- a/pkg/sentry/socket/unix/io.go
+++ b/pkg/sentry/socket/unix/io.go
@@ -83,6 +83,19 @@ type EndpointReader struct {
 	ControlTrunc bool
 }
 
+// Truncate calls RecvMsg on the endpoint without writing to a destination.
+func (r *EndpointReader) Truncate() error {
+	// Ignore bytes read since it will always be zero.
+	_, ms, c, ct, err := r.Endpoint.RecvMsg(r.Ctx, [][]byte{}, r.Creds, r.NumRights, r.Peek, r.From)
+	r.Control = c
+	r.ControlTrunc = ct
+	r.MsgSize = ms
+	if err != nil {
+		return err.ToError()
+	}
+	return nil
+}
+
 // ReadToBlocks implements safemem.Reader.ReadToBlocks.
 func (r *EndpointReader) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) {
 	return safemem.FromVecReaderFunc{func(bufs [][]byte) (int64, error) {
diff --git a/pkg/sentry/socket/unix/transport/BUILD b/pkg/sentry/socket/unix/transport/BUILD
index 788ad70d2..d7ba95dff 100644
--- a/pkg/sentry/socket/unix/transport/BUILD
+++ b/pkg/sentry/socket/unix/transport/BUILD
@@ -32,6 +32,7 @@ go_library(
         "//pkg/ilist",
         "//pkg/refs",
         "//pkg/sentry/context",
+        "//pkg/sync",
         "//pkg/syserr",
         "//pkg/tcpip",
         "//pkg/tcpip/buffer",
diff --git a/pkg/sentry/socket/unix/transport/connectioned.go b/pkg/sentry/socket/unix/transport/connectioned.go
index dea11e253..9e6fbc111 100644
--- a/pkg/sentry/socket/unix/transport/connectioned.go
+++ b/pkg/sentry/socket/unix/transport/connectioned.go
@@ -15,10 +15,9 @@
 package transport
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/context"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserr"
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/waiter"
diff --git a/pkg/sentry/socket/unix/transport/queue.go b/pkg/sentry/socket/unix/transport/queue.go
index e27b1c714..5dcd3d95e 100644
--- a/pkg/sentry/socket/unix/transport/queue.go
+++ b/pkg/sentry/socket/unix/transport/queue.go
@@ -15,9 +15,8 @@
 package transport
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/refs"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserr"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/socket/unix/transport/unix.go b/pkg/sentry/socket/unix/transport/unix.go
index 529a7a7a9..fcc0da332 100644
--- a/pkg/sentry/socket/unix/transport/unix.go
+++ b/pkg/sentry/socket/unix/transport/unix.go
@@ -16,11 +16,11 @@
 package transport
 
 import (
-	"sync"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/context"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserr"
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/buffer"
@@ -175,17 +175,25 @@ type Endpoint interface {
 	// types.
 	SetSockOpt(opt interface{}) *tcpip.Error
 
+	// SetSockOptBool sets a socket option for simple cases when a value has
+	// the int type.
+	SetSockOptBool(opt tcpip.SockOptBool, v bool) *tcpip.Error
+
 	// SetSockOptInt sets a socket option for simple cases when a value has
 	// the int type.
-	SetSockOptInt(opt tcpip.SockOpt, v int) *tcpip.Error
+	SetSockOptInt(opt tcpip.SockOptInt, v int) *tcpip.Error
 
 	// GetSockOpt gets a socket option. opt should be a pointer to one of the
 	// tcpip.*Option types.
 	GetSockOpt(opt interface{}) *tcpip.Error
 
+	// GetSockOptBool gets a socket option for simple cases when a return
+	// value has the int type.
+	GetSockOptBool(opt tcpip.SockOptBool) (bool, *tcpip.Error)
+
 	// GetSockOptInt gets a socket option for simple cases when a return
 	// value has the int type.
-	GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error)
+	GetSockOptInt(opt tcpip.SockOptInt) (int, *tcpip.Error)
 
 	// State returns the current state of the socket, as represented by Linux in
 	// procfs.
@@ -851,11 +859,19 @@ func (e *baseEndpoint) SetSockOpt(opt interface{}) *tcpip.Error {
 	return nil
 }
 
-func (e *baseEndpoint) SetSockOptInt(opt tcpip.SockOpt, v int) *tcpip.Error {
+func (e *baseEndpoint) SetSockOptBool(opt tcpip.SockOptBool, v bool) *tcpip.Error {
 	return nil
 }
 
-func (e *baseEndpoint) GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error) {
+func (e *baseEndpoint) SetSockOptInt(opt tcpip.SockOptInt, v int) *tcpip.Error {
+	return nil
+}
+
+func (e *baseEndpoint) GetSockOptBool(opt tcpip.SockOptBool) (bool, *tcpip.Error) {
+	return false, tcpip.ErrUnknownProtocolOption
+}
+
+func (e *baseEndpoint) GetSockOptInt(opt tcpip.SockOptInt) (int, *tcpip.Error) {
 	switch opt {
 	case tcpip.ReceiveQueueSizeOption:
 		v := 0
diff --git a/pkg/sentry/socket/unix/unix.go b/pkg/sentry/socket/unix/unix.go
index 885758054..91effe89a 100644
--- a/pkg/sentry/socket/unix/unix.go
+++ b/pkg/sentry/socket/unix/unix.go
@@ -544,8 +544,27 @@ func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags
 	if senderRequested {
 		r.From = &tcpip.FullAddress{}
 	}
+
+	doRead := func() (int64, error) {
+		return dst.CopyOutFrom(t, &r)
+	}
+
+	// If MSG_TRUNC is set with a zero byte destination then we still need
+	// to read the message and discard it, or in the case where MSG_PEEK is
+	// set, leave it be. In both cases the full message length must be
+	// returned.
+	if trunc && dst.Addrs.NumBytes() == 0 {
+		doRead = func() (int64, error) {
+			err := r.Truncate()
+			// Always return zero for bytes read since the destination size is
+			// zero.
+			return 0, err
+		}
+
+	}
+
 	var total int64
-	if n, err := dst.CopyOutFrom(t, &r); err != syserror.ErrWouldBlock || dontWait {
+	if n, err := doRead(); err != syserror.ErrWouldBlock || dontWait {
 		var from linux.SockAddr
 		var fromLen uint32
 		if r.From != nil && len([]byte(r.From.Addr)) != 0 {
@@ -580,7 +599,7 @@ func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags
 	defer s.EventUnregister(&e)
 
 	for {
-		if n, err := dst.CopyOutFrom(t, &r); err != syserror.ErrWouldBlock {
+		if n, err := doRead(); err != syserror.ErrWouldBlock {
 			var from linux.SockAddr
 			var fromLen uint32
 			if r.From != nil {
diff --git a/pkg/sentry/strace/BUILD b/pkg/sentry/strace/BUILD
index d46421199..aa1ac720c 100644
--- a/pkg/sentry/strace/BUILD
+++ b/pkg/sentry/strace/BUILD
@@ -10,7 +10,8 @@ go_library(
         "capability.go",
         "clone.go",
         "futex.go",
-        "linux64.go",
+        "linux64_amd64.go",
+        "linux64_arm64.go",
         "open.go",
         "poll.go",
         "ptrace.go",
diff --git a/pkg/sentry/strace/linux64.go b/pkg/sentry/strace/linux64_amd64.go
index e603f858f..1e823b685 100644
--- a/pkg/sentry/strace/linux64.go
+++ b/pkg/sentry/strace/linux64_amd64.go
@@ -1,4 +1,4 @@
-// Copyright 2018 The gVisor Authors.
+// Copyright 2019 The gVisor Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,8 +12,15 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// +build amd64
+
 package strace
 
+import (
+	"gvisor.dev/gvisor/pkg/abi"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
+)
+
 // linuxAMD64 provides a mapping of the Linux amd64 syscalls and their argument
 // types for display / formatting.
 var linuxAMD64 = SyscallMap{
@@ -365,3 +372,13 @@ var linuxAMD64 = SyscallMap{
 	434: makeSyscallInfo("pidfd_open", Hex, Hex),
 	435: makeSyscallInfo("clone3", Hex, Hex),
 }
+
+func init() {
+	syscallTables = append(syscallTables,
+		syscallTable{
+			os:       abi.Linux,
+			arch:     arch.AMD64,
+			syscalls: linuxAMD64,
+		},
+	)
+}
diff --git a/pkg/sentry/strace/linux64_arm64.go b/pkg/sentry/strace/linux64_arm64.go
new file mode 100644
index 000000000..c3ac5248d
--- /dev/null
+++ b/pkg/sentry/strace/linux64_arm64.go
@@ -0,0 +1,323 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build arm64
+
+package strace
+
+import (
+	"gvisor.dev/gvisor/pkg/abi"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
+)
+
+// linuxARM64 provides a mapping of the Linux arm64 syscalls and their argument
+// types for display / formatting.
+var linuxARM64 = SyscallMap{
+	0:   makeSyscallInfo("io_setup", Hex, Hex),
+	1:   makeSyscallInfo("io_destroy", Hex),
+	2:   makeSyscallInfo("io_submit", Hex, Hex, Hex),
+	3:   makeSyscallInfo("io_cancel", Hex, Hex, Hex),
+	4:   makeSyscallInfo("io_getevents", Hex, Hex, Hex, Hex, Timespec),
+	5:   makeSyscallInfo("setxattr", Path, Path, Hex, Hex, Hex),
+	6:   makeSyscallInfo("lsetxattr", Path, Path, Hex, Hex, Hex),
+	7:   makeSyscallInfo("fsetxattr", FD, Path, Hex, Hex, Hex),
+	8:   makeSyscallInfo("getxattr", Path, Path, Hex, Hex),
+	9:   makeSyscallInfo("lgetxattr", Path, Path, Hex, Hex),
+	10:  makeSyscallInfo("fgetxattr", FD, Path, Hex, Hex),
+	11:  makeSyscallInfo("listxattr", Path, Path, Hex),
+	12:  makeSyscallInfo("llistxattr", Path, Path, Hex),
+	13:  makeSyscallInfo("flistxattr", FD, Path, Hex),
+	14:  makeSyscallInfo("removexattr", Path, Path),
+	15:  makeSyscallInfo("lremovexattr", Path, Path),
+	16:  makeSyscallInfo("fremovexattr", FD, Path),
+	17:  makeSyscallInfo("getcwd", PostPath, Hex),
+	18:  makeSyscallInfo("lookup_dcookie", Hex, Hex, Hex),
+	19:  makeSyscallInfo("eventfd2", Hex, Hex),
+	20:  makeSyscallInfo("epoll_create1", Hex),
+	21:  makeSyscallInfo("epoll_ctl", Hex, Hex, FD, Hex),
+	22:  makeSyscallInfo("epoll_pwait", Hex, Hex, Hex, Hex, SigSet, Hex),
+	23:  makeSyscallInfo("dup", FD),
+	24:  makeSyscallInfo("dup3", FD, FD, Hex),
+	25:  makeSyscallInfo("fcntl", FD, Hex, Hex),
+	26:  makeSyscallInfo("inotify_init1", Hex),
+	27:  makeSyscallInfo("inotify_add_watch", Hex, Path, Hex),
+	28:  makeSyscallInfo("inotify_rm_watch", Hex, Hex),
+	29:  makeSyscallInfo("ioctl", FD, Hex, Hex),
+	30:  makeSyscallInfo("ioprio_set", Hex, Hex, Hex),
+	31:  makeSyscallInfo("ioprio_get", Hex, Hex),
+	32:  makeSyscallInfo("flock", FD, Hex),
+	33:  makeSyscallInfo("mknodat", FD, Path, Mode, Hex),
+	34:  makeSyscallInfo("mkdirat", FD, Path, Hex),
+	35:  makeSyscallInfo("unlinkat", FD, Path, Hex),
+	36:  makeSyscallInfo("symlinkat", Path, Hex, Path),
+	37:  makeSyscallInfo("linkat", FD, Path, Hex, Path, Hex),
+	38:  makeSyscallInfo("renameat", FD, Path, Hex, Path),
+	39:  makeSyscallInfo("umount2", Path, Hex),
+	40:  makeSyscallInfo("mount", Path, Path, Path, Hex, Path),
+	41:  makeSyscallInfo("pivot_root", Path, Path),
+	42:  makeSyscallInfo("nfsservctl", Hex, Hex, Hex),
+	43:  makeSyscallInfo("statfs", Path, Hex),
+	44:  makeSyscallInfo("fstatfs", FD, Hex),
+	45:  makeSyscallInfo("truncate", Path, Hex),
+	46:  makeSyscallInfo("ftruncate", FD, Hex),
+	47:  makeSyscallInfo("fallocate", FD, Hex, Hex, Hex),
+	48:  makeSyscallInfo("faccessat", FD, Path, Oct, Hex),
+	49:  makeSyscallInfo("chdir", Path),
+	50:  makeSyscallInfo("fchdir", FD),
+	51:  makeSyscallInfo("chroot", Path),
+	52:  makeSyscallInfo("fchmod", FD, Mode),
+	53:  makeSyscallInfo("fchmodat", FD, Path, Mode),
+	54:  makeSyscallInfo("fchownat", FD, Path, Hex, Hex, Hex),
+	55:  makeSyscallInfo("fchown", FD, Hex, Hex),
+	56:  makeSyscallInfo("openat", FD, Path, OpenFlags, Mode),
+	57:  makeSyscallInfo("close", FD),
+	58:  makeSyscallInfo("vhangup"),
+	59:  makeSyscallInfo("pipe2", PipeFDs, Hex),
+	60:  makeSyscallInfo("quotactl", Hex, Hex, Hex, Hex),
+	61:  makeSyscallInfo("getdents64", FD, Hex, Hex),
+	62:  makeSyscallInfo("lseek", Hex, Hex, Hex),
+	63:  makeSyscallInfo("read", FD, ReadBuffer, Hex),
+	64:  makeSyscallInfo("write", FD, WriteBuffer, Hex),
+	65:  makeSyscallInfo("readv", FD, ReadIOVec, Hex),
+	66:  makeSyscallInfo("writev", FD, WriteIOVec, Hex),
+	67:  makeSyscallInfo("pread64", FD, ReadBuffer, Hex, Hex),
+	68:  makeSyscallInfo("pwrite64", FD, WriteBuffer, Hex, Hex),
+	69:  makeSyscallInfo("preadv", FD, ReadIOVec, Hex, Hex),
+	70:  makeSyscallInfo("pwritev", FD, WriteIOVec, Hex, Hex),
+	71:  makeSyscallInfo("sendfile", FD, FD, Hex, Hex),
+	72:  makeSyscallInfo("pselect6", Hex, Hex, Hex, Hex, Hex, Hex),
+	73:  makeSyscallInfo("ppoll", PollFDs, Hex, Timespec, SigSet, Hex),
+	74:  makeSyscallInfo("signalfd4", Hex, Hex, Hex, Hex),
+	75:  makeSyscallInfo("vmsplice", FD, Hex, Hex, Hex),
+	76:  makeSyscallInfo("splice", FD, Hex, FD, Hex, Hex, Hex),
+	77:  makeSyscallInfo("tee", FD, FD, Hex, Hex),
+	78:  makeSyscallInfo("readlinkat", FD, Path, ReadBuffer, Hex),
+	79:  makeSyscallInfo("fstatat", FD, Path, Stat, Hex),
+	80:  makeSyscallInfo("fstat", FD, Stat),
+	81:  makeSyscallInfo("sync"),
+	82:  makeSyscallInfo("fsync", FD),
+	83:  makeSyscallInfo("fdatasync", FD),
+	84:  makeSyscallInfo("sync_file_range", FD, Hex, Hex, Hex),
+	85:  makeSyscallInfo("timerfd_create", Hex, Hex),
+	86:  makeSyscallInfo("timerfd_settime", FD, Hex, ItimerSpec, PostItimerSpec),
+	87:  makeSyscallInfo("timerfd_gettime", FD, PostItimerSpec),
+	88:  makeSyscallInfo("utimensat", FD, Path, UTimeTimespec, Hex),
+	89:  makeSyscallInfo("acct", Hex),
+	90:  makeSyscallInfo("capget", CapHeader, PostCapData),
+	91:  makeSyscallInfo("capset", CapHeader, CapData),
+	92:  makeSyscallInfo("personality", Hex),
+	93:  makeSyscallInfo("exit", Hex),
+	94:  makeSyscallInfo("exit_group", Hex),
+	95:  makeSyscallInfo("waitid", Hex, Hex, Hex, Hex, Rusage),
+	96:  makeSyscallInfo("set_tid_address", Hex),
+	97:  makeSyscallInfo("unshare", CloneFlags),
+	98:  makeSyscallInfo("futex", Hex, FutexOp, Hex, Timespec, Hex, Hex),
+	99:  makeSyscallInfo("set_robust_list", Hex, Hex),
+	100: makeSyscallInfo("get_robust_list", Hex, Hex, Hex),
+	101: makeSyscallInfo("nanosleep", Timespec, PostTimespec),
+	102: makeSyscallInfo("getitimer", ItimerType, PostItimerVal),
+	103: makeSyscallInfo("setitimer", ItimerType, ItimerVal, PostItimerVal),
+	104: makeSyscallInfo("kexec_load", Hex, Hex, Hex, Hex),
+	105: makeSyscallInfo("init_module", Hex, Hex, Hex),
+	106: makeSyscallInfo("delete_module", Hex, Hex),
+	107: makeSyscallInfo("timer_create", Hex, Hex, Hex),
+	108: makeSyscallInfo("timer_gettime", Hex, PostItimerSpec),
+	109: makeSyscallInfo("timer_getoverrun", Hex),
+	110: makeSyscallInfo("timer_settime", Hex, Hex, ItimerSpec, PostItimerSpec),
+	111: makeSyscallInfo("timer_delete", Hex),
+	112: makeSyscallInfo("clock_settime", Hex, Timespec),
+	113: makeSyscallInfo("clock_gettime", Hex, PostTimespec),
+	114: makeSyscallInfo("clock_getres", Hex, PostTimespec),
+	115: makeSyscallInfo("clock_nanosleep", Hex, Hex, Timespec, PostTimespec),
+	116: makeSyscallInfo("syslog", Hex, Hex, Hex),
+	117: makeSyscallInfo("ptrace", PtraceRequest, Hex, Hex, Hex),
+	118: makeSyscallInfo("sched_setparam", Hex, Hex),
+	119: makeSyscallInfo("sched_setscheduler", Hex, Hex, Hex),
+	120: makeSyscallInfo("sched_getscheduler", Hex),
+	121: makeSyscallInfo("sched_getparam", Hex, Hex),
+	122: makeSyscallInfo("sched_setaffinity", Hex, Hex, Hex),
+	123: makeSyscallInfo("sched_getaffinity", Hex, Hex, Hex),
+	124: makeSyscallInfo("sched_yield"),
+	125: makeSyscallInfo("sched_get_priority_max", Hex),
+	126: makeSyscallInfo("sched_get_priority_min", Hex),
+	127: makeSyscallInfo("sched_rr_get_interval", Hex, Hex),
+	128: makeSyscallInfo("restart_syscall"),
+	129: makeSyscallInfo("kill", Hex, Signal),
+	130: makeSyscallInfo("tkill", Hex, Signal),
+	131: makeSyscallInfo("tgkill", Hex, Hex, Signal),
+	132: makeSyscallInfo("sigaltstack", Hex, Hex),
+	133: makeSyscallInfo("rt_sigsuspend", Hex),
+	134: makeSyscallInfo("rt_sigaction", Signal, SigAction, PostSigAction),
+	135: makeSyscallInfo("rt_sigprocmask", SignalMaskAction, SigSet, PostSigSet, Hex),
+	136: makeSyscallInfo("rt_sigpending", Hex),
+	137: makeSyscallInfo("rt_sigtimedwait", SigSet, Hex, Timespec, Hex),
+	138: makeSyscallInfo("rt_sigqueueinfo", Hex, Signal, Hex),
+	139: makeSyscallInfo("rt_sigreturn"),
+	140: makeSyscallInfo("setpriority", Hex, Hex, Hex),
+	141: makeSyscallInfo("getpriority", Hex, Hex),
+	142: makeSyscallInfo("reboot", Hex, Hex, Hex, Hex),
+	143: makeSyscallInfo("setregid", Hex, Hex),
+	144: makeSyscallInfo("setgid", Hex),
+	145: makeSyscallInfo("setreuid", Hex, Hex),
+	146: makeSyscallInfo("setuid", Hex),
+	147: makeSyscallInfo("setresuid", Hex, Hex, Hex),
+	148: makeSyscallInfo("getresuid", Hex, Hex, Hex),
+	149: makeSyscallInfo("setresgid", Hex, Hex, Hex),
+	150: makeSyscallInfo("getresgid", Hex, Hex, Hex),
+	151: makeSyscallInfo("setfsuid", Hex),
+	152: makeSyscallInfo("setfsgid", Hex),
+	153: makeSyscallInfo("times", Hex),
+	154: makeSyscallInfo("setpgid", Hex, Hex),
+	155: makeSyscallInfo("getpgid", Hex),
+	156: makeSyscallInfo("getsid", Hex),
+	157: makeSyscallInfo("setsid"),
+	158: makeSyscallInfo("getgroups", Hex, Hex),
+	159: makeSyscallInfo("setgroups", Hex, Hex),
+	160: makeSyscallInfo("uname", Uname),
+	161: makeSyscallInfo("sethostname", Hex, Hex),
+	162: makeSyscallInfo("setdomainname", Hex, Hex),
+	163: makeSyscallInfo("getrlimit", Hex, Hex),
+	164: makeSyscallInfo("setrlimit", Hex, Hex),
+	165: makeSyscallInfo("getrusage", Hex, Rusage),
+	166: makeSyscallInfo("umask", Hex),
+	167: makeSyscallInfo("prctl", Hex, Hex, Hex, Hex, Hex),
+	168: makeSyscallInfo("getcpu", Hex, Hex, Hex),
+	169: makeSyscallInfo("gettimeofday", Timeval, Hex),
+	170: makeSyscallInfo("settimeofday", Timeval, Hex),
+	171: makeSyscallInfo("adjtimex", Hex),
+	172: makeSyscallInfo("getpid"),
+	173: makeSyscallInfo("getppid"),
+	174: makeSyscallInfo("getuid"),
+	175: makeSyscallInfo("geteuid"),
+	176: makeSyscallInfo("getgid"),
+	177: makeSyscallInfo("getegid"),
+	178: makeSyscallInfo("gettid"),
+	179: makeSyscallInfo("sysinfo", Hex),
+	180: makeSyscallInfo("mq_open", Hex, Hex, Hex, Hex),
+	181: makeSyscallInfo("mq_unlink", Hex),
+	182: makeSyscallInfo("mq_timedsend", Hex, Hex, Hex, Hex, Hex),
+	183: makeSyscallInfo("mq_timedreceive", Hex, Hex, Hex, Hex, Hex),
+	184: makeSyscallInfo("mq_notify", Hex, Hex),
+	185: makeSyscallInfo("mq_getsetattr", Hex, Hex, Hex),
+	186: makeSyscallInfo("msgget", Hex, Hex),
+	187: makeSyscallInfo("msgctl", Hex, Hex, Hex),
+	188: makeSyscallInfo("msgrcv", Hex, Hex, Hex, Hex, Hex),
+	189: makeSyscallInfo("msgsnd", Hex, Hex, Hex, Hex),
+	190: makeSyscallInfo("semget", Hex, Hex, Hex),
+	191: makeSyscallInfo("semctl", Hex, Hex, Hex, Hex),
+	192: makeSyscallInfo("semtimedop", Hex, Hex, Hex, Hex),
+	193: makeSyscallInfo("semop", Hex, Hex, Hex),
+	194: makeSyscallInfo("shmget", Hex, Hex, Hex),
+	195: makeSyscallInfo("shmctl", Hex, Hex, Hex),
+	196: makeSyscallInfo("shmat", Hex, Hex, Hex),
+	197: makeSyscallInfo("shmdt", Hex),
+	198: makeSyscallInfo("socket", SockFamily, SockType, SockProtocol),
+	199: makeSyscallInfo("socketpair", SockFamily, SockType, SockProtocol, Hex),
+	200: makeSyscallInfo("bind", FD, SockAddr, Hex),
+	201: makeSyscallInfo("listen", FD, Hex),
+	202: makeSyscallInfo("accept", FD, PostSockAddr, SockLen),
+	203: makeSyscallInfo("connect", FD, SockAddr, Hex),
+	204: makeSyscallInfo("getsockname", FD, PostSockAddr, SockLen),
+	205: makeSyscallInfo("getpeername", FD, PostSockAddr, SockLen),
+	206: makeSyscallInfo("sendto", FD, Hex, Hex, Hex, SockAddr, Hex),
+	207: makeSyscallInfo("recvfrom", FD, Hex, Hex, Hex, PostSockAddr, SockLen),
+	208: makeSyscallInfo("setsockopt", FD, Hex, Hex, Hex, Hex),
+	209: makeSyscallInfo("getsockopt", FD, Hex, Hex, Hex, Hex),
+	210: makeSyscallInfo("shutdown", FD, Hex),
+	211: makeSyscallInfo("sendmsg", FD, SendMsgHdr, Hex),
+	212: makeSyscallInfo("recvmsg", FD, RecvMsgHdr, Hex),
+	213: makeSyscallInfo("readahead", Hex, Hex, Hex),
+	214: makeSyscallInfo("brk", Hex),
+	215: makeSyscallInfo("munmap", Hex, Hex),
+	216: makeSyscallInfo("mremap", Hex, Hex, Hex, Hex, Hex),
+	217: makeSyscallInfo("add_key", Hex, Hex, Hex, Hex, Hex),
+	218: makeSyscallInfo("request_key", Hex, Hex, Hex, Hex),
+	219: makeSyscallInfo("keyctl", Hex, Hex, Hex, Hex, Hex),
+	220: makeSyscallInfo("clone", CloneFlags, Hex, Hex, Hex, Hex),
+	221: makeSyscallInfo("execve", Path, ExecveStringVector, ExecveStringVector),
+	222: makeSyscallInfo("mmap", Hex, Hex, Hex, Hex, FD, Hex),
+	223: makeSyscallInfo("fadvise64", FD, Hex, Hex, Hex),
+	224: makeSyscallInfo("swapon", Hex, Hex),
+	225: makeSyscallInfo("swapoff", Hex),
+	226: makeSyscallInfo("mprotect", Hex, Hex, Hex),
+	227: makeSyscallInfo("msync", Hex, Hex, Hex),
+	228: makeSyscallInfo("mlock", Hex, Hex),
+	229: makeSyscallInfo("munlock", Hex, Hex),
+	230: makeSyscallInfo("mlockall", Hex),
+	231: makeSyscallInfo("munlockall"),
+	232: makeSyscallInfo("mincore", Hex, Hex, Hex),
+	233: makeSyscallInfo("madvise", Hex, Hex, Hex),
+	234: makeSyscallInfo("remap_file_pages", Hex, Hex, Hex, Hex, Hex),
+	235: makeSyscallInfo("mbind", Hex, Hex, Hex, Hex, Hex, Hex),
+	236: makeSyscallInfo("get_mempolicy", Hex, Hex, Hex, Hex, Hex),
+	237: makeSyscallInfo("set_mempolicy", Hex, Hex, Hex),
+	238: makeSyscallInfo("migrate_pages", Hex, Hex, Hex, Hex),
+	239: makeSyscallInfo("move_pages", Hex, Hex, Hex, Hex, Hex, Hex),
+	240: makeSyscallInfo("rt_tgsigqueueinfo", Hex, Hex, Signal, Hex),
+	241: makeSyscallInfo("perf_event_open", Hex, Hex, Hex, Hex, Hex),
+	242: makeSyscallInfo("accept4", FD, PostSockAddr, SockLen, SockFlags),
+	243: makeSyscallInfo("recvmmsg", FD, Hex, Hex, Hex, Hex),
+
+	260: makeSyscallInfo("wait4", Hex, Hex, Hex, Rusage),
+	261: makeSyscallInfo("prlimit64", Hex, Hex, Hex, Hex),
+	262: makeSyscallInfo("fanotify_init", Hex, Hex),
+	263: makeSyscallInfo("fanotify_mark", Hex, Hex, Hex, Hex, Hex),
+	264: makeSyscallInfo("name_to_handle_at", FD, Hex, Hex, Hex, Hex),
+	265: makeSyscallInfo("open_by_handle_at", FD, Hex, Hex),
+	266: makeSyscallInfo("clock_adjtime", Hex, Hex),
+	267: makeSyscallInfo("syncfs", FD),
+	268: makeSyscallInfo("setns", FD, Hex),
+	269: makeSyscallInfo("sendmmsg", FD, Hex, Hex, Hex),
+	270: makeSyscallInfo("process_vm_readv", Hex, ReadIOVec, Hex, IOVec, Hex, Hex),
+	271: makeSyscallInfo("process_vm_writev", Hex, IOVec, Hex, WriteIOVec, Hex, Hex),
+	272: makeSyscallInfo("kcmp", Hex, Hex, Hex, Hex, Hex),
+	273: makeSyscallInfo("finit_module", Hex, Hex, Hex),
+	274: makeSyscallInfo("sched_setattr", Hex, Hex, Hex),
+	275: makeSyscallInfo("sched_getattr", Hex, Hex, Hex),
+	276: makeSyscallInfo("renameat2", FD, Path, Hex, Path, Hex),
+	277: makeSyscallInfo("seccomp", Hex, Hex, Hex),
+	278: makeSyscallInfo("getrandom", Hex, Hex, Hex),
+	279: makeSyscallInfo("memfd_create", Path, Hex),
+	280: makeSyscallInfo("bpf", Hex, Hex, Hex),
+	281: makeSyscallInfo("execveat", FD, Path, Hex, Hex, Hex),
+	282: makeSyscallInfo("userfaultfd", Hex),
+	283: makeSyscallInfo("membarrier", Hex),
+	284: makeSyscallInfo("mlock2", Hex, Hex, Hex),
+	285: makeSyscallInfo("copy_file_range", FD, Hex, FD, Hex, Hex, Hex),
+	286: makeSyscallInfo("preadv2", FD, ReadIOVec, Hex, Hex, Hex),
+	287: makeSyscallInfo("pwritev2", FD, WriteIOVec, Hex, Hex, Hex),
+	291: makeSyscallInfo("statx", FD, Path, Hex, Hex, Hex),
+	292: makeSyscallInfo("io_pgetevents", Hex, Hex, Hex, Hex, Timespec, SigSet),
+	293: makeSyscallInfo("rseq", Hex, Hex, Hex, Hex),
+	424: makeSyscallInfo("pidfd_send_signal", FD, Signal, Hex, Hex),
+	425: makeSyscallInfo("io_uring_setup", Hex, Hex),
+	426: makeSyscallInfo("io_uring_enter", FD, Hex, Hex, Hex, SigSet, Hex),
+	427: makeSyscallInfo("io_uring_register", FD, Hex, Hex, Hex),
+	428: makeSyscallInfo("open_tree", FD, Path, Hex),
+	429: makeSyscallInfo("move_mount", FD, Path, FD, Path, Hex),
+	430: makeSyscallInfo("fsopen", Path, Hex), // Not quite a path, but close.
+	431: makeSyscallInfo("fsconfig", FD, Hex, Hex, Hex, Hex),
+	432: makeSyscallInfo("fsmount", FD, Hex, Hex),
+	433: makeSyscallInfo("fspick", FD, Path, Hex),
+	434: makeSyscallInfo("pidfd_open", Hex, Hex),
+	435: makeSyscallInfo("clone3", Hex, Hex),
+}
+
+func init() {
+	syscallTables = append(syscallTables,
+		syscallTable{
+			os:       abi.Linux,
+			arch:     arch.ARM64,
+			syscalls: linuxARM64})
+}
diff --git a/pkg/sentry/strace/syscalls.go b/pkg/sentry/strace/syscalls.go
index e5d486c4e..24e29a2ba 100644
--- a/pkg/sentry/strace/syscalls.go
+++ b/pkg/sentry/strace/syscalls.go
@@ -250,14 +250,7 @@ type syscallTable struct {
 	syscalls SyscallMap
 }
 
-// syscallTables contains all syscall tables.
-var syscallTables = []syscallTable{
-	{
-		os:       abi.Linux,
-		arch:     arch.AMD64,
-		syscalls: linuxAMD64,
-	},
-}
+var syscallTables []syscallTable
 
 // Lookup returns the SyscallMap for the OS/Arch combination. The returned map
 // must not be changed.
diff --git a/pkg/sentry/syscalls/linux/BUILD b/pkg/sentry/syscalls/linux/BUILD
index a76975cee..aa05e208a 100644
--- a/pkg/sentry/syscalls/linux/BUILD
+++ b/pkg/sentry/syscalls/linux/BUILD
@@ -91,6 +91,7 @@ go_library(
         "//pkg/sentry/syscalls",
         "//pkg/sentry/usage",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserr",
         "//pkg/syserror",
         "//pkg/waiter",
diff --git a/pkg/sentry/syscalls/linux/error.go b/pkg/sentry/syscalls/linux/error.go
index 1d9018c96..60469549d 100644
--- a/pkg/sentry/syscalls/linux/error.go
+++ b/pkg/sentry/syscalls/linux/error.go
@@ -16,13 +16,13 @@ package linux
 
 import (
 	"io"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/metric"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/time/BUILD b/pkg/sentry/time/BUILD
index 18e212dff..3cde3a0be 100644
--- a/pkg/sentry/time/BUILD
+++ b/pkg/sentry/time/BUILD
@@ -9,7 +9,7 @@ go_template_instance(
     out = "seqatomic_parameters_unsafe.go",
     package = "time",
     suffix = "Parameters",
-    template = "//pkg/syncutil:generic_seqatomic",
+    template = "//pkg/sync:generic_seqatomic",
     types = {
         "Value": "Parameters",
     },
@@ -36,7 +36,7 @@ go_library(
     deps = [
         "//pkg/log",
         "//pkg/metric",
-        "//pkg/syncutil",
+        "//pkg/sync",
         "//pkg/syserror",
     ],
 )
diff --git a/pkg/sentry/time/calibrated_clock.go b/pkg/sentry/time/calibrated_clock.go
index 318503277..f9a93115d 100644
--- a/pkg/sentry/time/calibrated_clock.go
+++ b/pkg/sentry/time/calibrated_clock.go
@@ -17,11 +17,11 @@
 package time
 
 import (
-	"sync"
 	"time"
 
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/metric"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/usage/BUILD b/pkg/sentry/usage/BUILD
index c32fe3241..5518ac3d0 100644
--- a/pkg/sentry/usage/BUILD
+++ b/pkg/sentry/usage/BUILD
@@ -18,5 +18,6 @@ go_library(
     deps = [
         "//pkg/bits",
         "//pkg/memutil",
+        "//pkg/sync",
     ],
 )
diff --git a/pkg/sentry/usage/memory.go b/pkg/sentry/usage/memory.go
index d6ef644d8..538c645eb 100644
--- a/pkg/sentry/usage/memory.go
+++ b/pkg/sentry/usage/memory.go
@@ -17,12 +17,12 @@ package usage
 import (
 	"fmt"
 	"os"
-	"sync"
 	"sync/atomic"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/bits"
 	"gvisor.dev/gvisor/pkg/memutil"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // MemoryKind represents a type of memory used by the application.
diff --git a/pkg/sentry/vfs/BUILD b/pkg/sentry/vfs/BUILD
index 4c6aa04a1..35c7be259 100644
--- a/pkg/sentry/vfs/BUILD
+++ b/pkg/sentry/vfs/BUILD
@@ -34,7 +34,7 @@ go_library(
         "//pkg/sentry/kernel/auth",
         "//pkg/sentry/memmap",
         "//pkg/sentry/usermem",
-        "//pkg/syncutil",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/waiter",
     ],
@@ -54,6 +54,7 @@ go_test(
         "//pkg/sentry/context/contexttest",
         "//pkg/sentry/kernel/auth",
         "//pkg/sentry/usermem",
+        "//pkg/sync",
         "//pkg/syserror",
     ],
 )
diff --git a/pkg/sentry/vfs/dentry.go b/pkg/sentry/vfs/dentry.go
index 1bc9c4a38..486a76475 100644
--- a/pkg/sentry/vfs/dentry.go
+++ b/pkg/sentry/vfs/dentry.go
@@ -16,9 +16,9 @@ package vfs
 
 import (
 	"fmt"
-	"sync"
 	"sync/atomic"
 
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/vfs/file_description_impl_util.go b/pkg/sentry/vfs/file_description_impl_util.go
index 66eb57bc2..c00b3c84b 100644
--- a/pkg/sentry/vfs/file_description_impl_util.go
+++ b/pkg/sentry/vfs/file_description_impl_util.go
@@ -17,13 +17,13 @@ package vfs
 import (
 	"bytes"
 	"io"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
diff --git a/pkg/sentry/vfs/mount_test.go b/pkg/sentry/vfs/mount_test.go
index adff0b94b..3b933468d 100644
--- a/pkg/sentry/vfs/mount_test.go
+++ b/pkg/sentry/vfs/mount_test.go
@@ -17,8 +17,9 @@ package vfs
 import (
 	"fmt"
 	"runtime"
-	"sync"
 	"testing"
+
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 func TestMountTableLookupEmpty(t *testing.T) {
diff --git a/pkg/sentry/vfs/mount_unsafe.go b/pkg/sentry/vfs/mount_unsafe.go
index ab13fa461..bd90d36c4 100644
--- a/pkg/sentry/vfs/mount_unsafe.go
+++ b/pkg/sentry/vfs/mount_unsafe.go
@@ -26,7 +26,7 @@ import (
 	"sync/atomic"
 	"unsafe"
 
-	"gvisor.dev/gvisor/pkg/syncutil"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // mountKey represents the location at which a Mount is mounted. It is
@@ -75,7 +75,7 @@ type mountTable struct {
 	// intrinsics and inline assembly, limiting the performance of this
 	// approach.)
 
-	seq  syncutil.SeqCount
+	seq  sync.SeqCount
 	seed uint32 // for hashing keys
 
 	// size holds both length (number of elements) and capacity (number of
diff --git a/pkg/sentry/vfs/pathname.go b/pkg/sentry/vfs/pathname.go
index 8e155654f..cf80df90e 100644
--- a/pkg/sentry/vfs/pathname.go
+++ b/pkg/sentry/vfs/pathname.go
@@ -15,10 +15,9 @@
 package vfs
 
 import (
-	"sync"
-
 	"gvisor.dev/gvisor/pkg/fspath"
 	"gvisor.dev/gvisor/pkg/sentry/context"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/vfs/resolving_path.go b/pkg/sentry/vfs/resolving_path.go
index f0641d314..8a0b382f6 100644
--- a/pkg/sentry/vfs/resolving_path.go
+++ b/pkg/sentry/vfs/resolving_path.go
@@ -16,11 +16,11 @@ package vfs
 
 import (
 	"fmt"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/fspath"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/vfs/vfs.go b/pkg/sentry/vfs/vfs.go
index ea2db7031..1f21b0b31 100644
--- a/pkg/sentry/vfs/vfs.go
+++ b/pkg/sentry/vfs/vfs.go
@@ -29,12 +29,12 @@ package vfs
 
 import (
 	"fmt"
-	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/fspath"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 )
 
diff --git a/pkg/sentry/watchdog/BUILD b/pkg/sentry/watchdog/BUILD
index 4d8435265..28f21f13d 100644
--- a/pkg/sentry/watchdog/BUILD
+++ b/pkg/sentry/watchdog/BUILD
@@ -13,5 +13,6 @@ go_library(
         "//pkg/metric",
         "//pkg/sentry/kernel",
         "//pkg/sentry/kernel/time",
+        "//pkg/sync",
     ],
 )
diff --git a/pkg/sentry/watchdog/watchdog.go b/pkg/sentry/watchdog/watchdog.go
index 5e4611333..bfb2fac26 100644
--- a/pkg/sentry/watchdog/watchdog.go
+++ b/pkg/sentry/watchdog/watchdog.go
@@ -32,7 +32,6 @@ package watchdog
 import (
 	"bytes"
 	"fmt"
-	"sync"
 	"time"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -40,6 +39,7 @@ import (
 	"gvisor.dev/gvisor/pkg/metric"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // Opts configures the watchdog.
author	Kevin Krakauer <krakauer@google.com>	2020-01-13 16:06:29 -0800
committer	Kevin Krakauer <krakauer@google.com>	2020-01-13 16:06:29 -0800
commit	d51eaa59c020cca9b7bc27cec0338ead089f3ed6 (patch)
tree	3b41776af9426496567573ed17698562daf39006 /pkg/sentry
parent	d793677cd424fef10ac0b080871d181db0bcdec0 (diff)
parent	1c3d3c70b93d483894dd49fb444171347f0ca250 (diff)