New sync package.

* Rename syncutil to sync.
* Add aliases to sync types.
* Replace existing usage of standard library sync package.

This will make it easier to swap out synchronization primitives. For example,
this will allow us to use primitives from github.com/sasha-s/go-deadlock to
check for lock ordering violations.

Updates #1472

PiperOrigin-RevId: 289033387

42 files changed, 52 insertions, 44 deletions

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: