Fix runsc syscall documentation generation.

We can register any number of tables with any number of architectures, and
need not limit the definitions to the architecture in question. This allows
runsc to generate documentation for all architectures simultaneously.

Similarly, this simplifies the VFSv2 patching process.

PiperOrigin-RevId: 310224827

5 files changed, 4 insertions, 76 deletions

diff --git a/runsc/boot/BUILD b/runsc/boot/BUILD
index 0e71e800b..a907c103b 100644
--- a/runsc/boot/BUILD
+++ b/runsc/boot/BUILD
@@ -15,8 +15,6 @@ go_library(
         "fs.go",
         "limits.go",
         "loader.go",
-        "loader_amd64.go",
-        "loader_arm64.go",
         "network.go",
         "strace.go",
         "vfs.go",
@@ -77,7 +75,6 @@ go_library(
         "//pkg/sentry/socket/unix",
         "//pkg/sentry/state",
         "//pkg/sentry/strace",
-        "//pkg/sentry/syscalls/linux",
         "//pkg/sentry/syscalls/linux/vfs2",
         "//pkg/sentry/time",
         "//pkg/sentry/unimpl:unimplemented_syscall_go_proto",
@@ -126,7 +123,6 @@ go_test(
         "//pkg/p9",
         "//pkg/sentry/contexttest",
         "//pkg/sentry/fs",
-        "//pkg/sentry/kernel",
         "//pkg/sentry/vfs",
         "//pkg/sync",
         "//pkg/unet",
diff --git a/runsc/boot/loader.go b/runsc/boot/loader.go
index 79ef3a880..8c8bad11c 100644
--- a/runsc/boot/loader.go
+++ b/runsc/boot/loader.go
@@ -77,8 +77,6 @@ import (
 	_ "gvisor.dev/gvisor/pkg/sentry/socket/unix"
 )
 
-var syscallTable *kernel.SyscallTable
-
 // Loader keeps state needed to start the kernel and run the container..
 type Loader struct {
 	// k is the kernel.
@@ -204,14 +202,12 @@ func New(args Args) (*Loader, error) {
 		return nil, fmt.Errorf("setting up memory usage: %v", err)
 	}
 
-	// Patch the syscall table.
-	kernel.VFS2Enabled = args.Conf.VFS2
-	if kernel.VFS2Enabled {
-		vfs2.Override(syscallTable.Table)
+	// Is this a VFSv2 kernel?
+	if args.Conf.VFS2 {
+		kernel.VFS2Enabled = true
+		vfs2.Override()
 	}
 
-	kernel.RegisterSyscallTable(syscallTable)
-
 	// Create kernel and platform.
 	p, err := createPlatform(args.Conf, args.Device)
 	if err != nil {
diff --git a/runsc/boot/loader_amd64.go b/runsc/boot/loader_amd64.go
deleted file mode 100644
index 78df86611..000000000
--- a/runsc/boot/loader_amd64.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// 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 amd64
-
-package boot
-
-import (
-	"gvisor.dev/gvisor/pkg/sentry/syscalls/linux"
-)
-
-func init() {
-	// Set the global syscall table.
-	syscallTable = linux.AMD64
-}
diff --git a/runsc/boot/loader_arm64.go b/runsc/boot/loader_arm64.go
deleted file mode 100644
index 250785010..000000000
--- a/runsc/boot/loader_arm64.go
+++ /dev/null
@@ -1,26 +0,0 @@
-// 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 boot
-
-import (
-	"gvisor.dev/gvisor/pkg/sentry/syscalls/linux"
-)
-
-func init() {
-	// Set the global syscall table.
-	syscallTable = linux.ARM64
-}
diff --git a/runsc/boot/loader_test.go b/runsc/boot/loader_test.go
index 7a30fea70..e448fd773 100644
--- a/runsc/boot/loader_test.go
+++ b/runsc/boot/loader_test.go
@@ -31,7 +31,6 @@ import (
 	"gvisor.dev/gvisor/pkg/p9"
 	"gvisor.dev/gvisor/pkg/sentry/contexttest"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
-	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/unet"
@@ -69,11 +68,6 @@ func testSpec() *specs.Spec {
 	}
 }
 
-func resetSyscallTable() {
-	kernel.VFS2Enabled = false
-	kernel.FlushSyscallTablesTestOnly()
-}
-
 // startGofer starts a new gofer routine serving 'root' path. It returns the
 // sandbox side of the connection, and a function that when called will stop the
 // gofer.
@@ -150,13 +144,11 @@ func createLoader(vfsEnabled bool, spec *specs.Spec) (*Loader, func(), error) {
 
 // TestRun runs a simple application in a sandbox and checks that it succeeds.
 func TestRun(t *testing.T) {
-	defer resetSyscallTable()
 	doRun(t, false)
 }
 
 // TestRunVFS2 runs TestRun in VFSv2.
 func TestRunVFS2(t *testing.T) {
-	defer resetSyscallTable()
 	doRun(t, true)
 }
 
@@ -199,13 +191,11 @@ func doRun(t *testing.T, vfsEnabled bool) {
 // TestStartSignal tests that the controller Start message will cause
 // WaitForStartSignal to return.
 func TestStartSignal(t *testing.T) {
-	defer resetSyscallTable()
 	doStartSignal(t, false)
 }
 
 // TestStartSignalVFS2 does TestStartSignal with VFS2.
 func TestStartSignalVFS2(t *testing.T) {
-	defer resetSyscallTable()
 	doStartSignal(t, true)
 }
 
@@ -477,8 +467,6 @@ func TestCreateMountNamespace(t *testing.T) {
 func TestCreateMountNamespaceVFS2(t *testing.T) {
 	for _, tc := range createMountTestcases(true /* vfs2 */) {
 		t.Run(tc.name, func(t *testing.T) {
-			defer resetSyscallTable()
-
 			spec := testSpec()
 			spec.Mounts = tc.spec.Mounts
 			spec.Root = tc.spec.Root