Implement sysfs.

PiperOrigin-RevId: 290822487

3 files changed, 8 insertions, 167 deletions

diff --git a/pkg/sentry/fsimpl/proc/BUILD b/pkg/sentry/fsimpl/proc/BUILD
index f69aa19c4..c5b79fb38 100644
--- a/pkg/sentry/fsimpl/proc/BUILD
+++ b/pkg/sentry/fsimpl/proc/BUILD
@@ -44,30 +44,19 @@ go_test(
     name = "proc_test",
     size = "small",
     srcs = [
-        "boot_test.go",
         "tasks_sys_test.go",
         "tasks_test.go",
     ],
     embed = [":proc"],
     deps = [
         "//pkg/abi/linux",
-        "//pkg/cpuid",
         "//pkg/fspath",
-        "//pkg/memutil",
         "//pkg/sentry/context",
         "//pkg/sentry/context/contexttest",
-        "//pkg/sentry/fs",
+        "//pkg/sentry/fsimpl/testutil",
         "//pkg/sentry/inet",
         "//pkg/sentry/kernel",
         "//pkg/sentry/kernel/auth",
-        "//pkg/sentry/kernel/sched",
-        "//pkg/sentry/limits",
-        "//pkg/sentry/loader",
-        "//pkg/sentry/pgalloc",
-        "//pkg/sentry/platform",
-        "//pkg/sentry/platform/kvm",
-        "//pkg/sentry/platform/ptrace",
-        "//pkg/sentry/time",
         "//pkg/sentry/usermem",
         "//pkg/sentry/vfs",
         "//pkg/syserror",
diff --git a/pkg/sentry/fsimpl/proc/boot_test.go b/pkg/sentry/fsimpl/proc/boot_test.go
deleted file mode 100644
index 84a93ee56..000000000
--- a/pkg/sentry/fsimpl/proc/boot_test.go
+++ /dev/null
@@ -1,149 +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.
-
-package proc
-
-import (
-	"flag"
-	"fmt"
-	"os"
-	"runtime"
-
-	"gvisor.dev/gvisor/pkg/abi/linux"
-	"gvisor.dev/gvisor/pkg/cpuid"
-	"gvisor.dev/gvisor/pkg/memutil"
-	"gvisor.dev/gvisor/pkg/sentry/context"
-	"gvisor.dev/gvisor/pkg/sentry/fs"
-	"gvisor.dev/gvisor/pkg/sentry/kernel"
-	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
-	"gvisor.dev/gvisor/pkg/sentry/kernel/sched"
-	"gvisor.dev/gvisor/pkg/sentry/limits"
-	"gvisor.dev/gvisor/pkg/sentry/loader"
-	"gvisor.dev/gvisor/pkg/sentry/pgalloc"
-	"gvisor.dev/gvisor/pkg/sentry/platform"
-	"gvisor.dev/gvisor/pkg/sentry/time"
-
-	// Platforms are plugable.
-	_ "gvisor.dev/gvisor/pkg/sentry/platform/kvm"
-	_ "gvisor.dev/gvisor/pkg/sentry/platform/ptrace"
-)
-
-var (
-	platformFlag = flag.String("platform", "ptrace", "specify which platform to use")
-)
-
-// boot initializes a new bare bones kernel for test.
-func boot() (*kernel.Kernel, error) {
-	platformCtr, err := platform.Lookup(*platformFlag)
-	if err != nil {
-		return nil, fmt.Errorf("platform not found: %v", err)
-	}
-	deviceFile, err := platformCtr.OpenDevice()
-	if err != nil {
-		return nil, fmt.Errorf("creating platform: %v", err)
-	}
-	plat, err := platformCtr.New(deviceFile)
-	if err != nil {
-		return nil, fmt.Errorf("creating platform: %v", err)
-	}
-
-	k := &kernel.Kernel{
-		Platform: plat,
-	}
-
-	mf, err := createMemoryFile()
-	if err != nil {
-		return nil, err
-	}
-	k.SetMemoryFile(mf)
-
-	// Pass k as the platform since it is savable, unlike the actual platform.
-	vdso, err := loader.PrepareVDSO(nil, k)
-	if err != nil {
-		return nil, fmt.Errorf("creating vdso: %v", err)
-	}
-
-	// Create timekeeper.
-	tk, err := kernel.NewTimekeeper(k, vdso.ParamPage.FileRange())
-	if err != nil {
-		return nil, fmt.Errorf("creating timekeeper: %v", err)
-	}
-	tk.SetClocks(time.NewCalibratedClocks())
-
-	creds := auth.NewRootCredentials(auth.NewRootUserNamespace())
-
-	// Initiate the Kernel object, which is required by the Context passed
-	// to createVFS in order to mount (among other things) procfs.
-	if err = k.Init(kernel.InitKernelArgs{
-		ApplicationCores:            uint(runtime.GOMAXPROCS(-1)),
-		FeatureSet:                  cpuid.HostFeatureSet(),
-		Timekeeper:                  tk,
-		RootUserNamespace:           creds.UserNamespace,
-		Vdso:                        vdso,
-		RootUTSNamespace:            kernel.NewUTSNamespace("hostname", "domain", creds.UserNamespace),
-		RootIPCNamespace:            kernel.NewIPCNamespace(creds.UserNamespace),
-		RootAbstractSocketNamespace: kernel.NewAbstractSocketNamespace(),
-		PIDNamespace:                kernel.NewRootPIDNamespace(creds.UserNamespace),
-	}); err != nil {
-		return nil, fmt.Errorf("initializing kernel: %v", err)
-	}
-
-	ctx := k.SupervisorContext()
-
-	// Create mount namespace without root as it's the minimum required to create
-	// the global thread group.
-	mntns, err := fs.NewMountNamespace(ctx, nil)
-	if err != nil {
-		return nil, err
-	}
-	ls, err := limits.NewLinuxLimitSet()
-	if err != nil {
-		return nil, err
-	}
-	tg := k.NewThreadGroup(mntns, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, ls)
-	k.TestOnly_SetGlobalInit(tg)
-
-	return k, nil
-}
-
-// createTask creates a new bare bones task for tests.
-func createTask(ctx context.Context, name string, tc *kernel.ThreadGroup) (*kernel.Task, error) {
-	k := kernel.KernelFromContext(ctx)
-	config := &kernel.TaskConfig{
-		Kernel:                  k,
-		ThreadGroup:             tc,
-		TaskContext:             &kernel.TaskContext{Name: name},
-		Credentials:             auth.CredentialsFromContext(ctx),
-		AllowedCPUMask:          sched.NewFullCPUSet(k.ApplicationCores()),
-		UTSNamespace:            kernel.UTSNamespaceFromContext(ctx),
-		IPCNamespace:            kernel.IPCNamespaceFromContext(ctx),
-		AbstractSocketNamespace: kernel.NewAbstractSocketNamespace(),
-	}
-	return k.TaskSet().NewTask(config)
-}
-
-func createMemoryFile() (*pgalloc.MemoryFile, error) {
-	const memfileName = "test-memory"
-	memfd, err := memutil.CreateMemFD(memfileName, 0)
-	if err != nil {
-		return nil, fmt.Errorf("error creating memfd: %v", err)
-	}
-	memfile := os.NewFile(uintptr(memfd), memfileName)
-	mf, err := pgalloc.NewMemoryFile(memfile, pgalloc.MemoryFileOpts{})
-	if err != nil {
-		memfile.Close()
-		return nil, fmt.Errorf("error creating pgalloc.MemoryFile: %v", err)
-	}
-	return mf, nil
-}
diff --git a/pkg/sentry/fsimpl/proc/tasks_test.go b/pkg/sentry/fsimpl/proc/tasks_test.go
index 002d2f73b..41977d816 100644
--- a/pkg/sentry/fsimpl/proc/tasks_test.go
+++ b/pkg/sentry/fsimpl/proc/tasks_test.go
@@ -24,6 +24,7 @@ import (
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/fspath"
 	"gvisor.dev/gvisor/pkg/sentry/context"
+	"gvisor.dev/gvisor/pkg/sentry/fsimpl/testutil"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
@@ -134,7 +135,7 @@ func checkFiles(gots []vfs.Dirent, wants map[string]vfs.Dirent) ([]vfs.Dirent, e
 }
 
 func setup() (context.Context, *vfs.VirtualFilesystem, vfs.VirtualDentry, error) {
-	k, err := boot()
+	k, err := testutil.Boot()
 	if err != nil {
 		return nil, nil, vfs.VirtualDentry{}, fmt.Errorf("creating kernel: %v", err)
 	}
@@ -206,7 +207,7 @@ func TestTasks(t *testing.T) {
 	var tasks []*kernel.Task
 	for i := 0; i < 5; i++ {
 		tc := k.NewThreadGroup(nil, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, k.GlobalInit().Limits())
-		task, err := createTask(ctx, fmt.Sprintf("name-%d", i), tc)
+		task, err := testutil.CreateTask(ctx, fmt.Sprintf("name-%d", i), tc)
 		if err != nil {
 			t.Fatalf("CreateTask(): %v", err)
 		}
@@ -298,7 +299,7 @@ func TestTasksOffset(t *testing.T) {
 	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 {
+		if _, err := testutil.CreateTask(ctx, fmt.Sprintf("name-%d", i), tc); err != nil {
 			t.Fatalf("CreateTask(): %v", err)
 		}
 	}
@@ -417,7 +418,7 @@ func TestTask(t *testing.T) {
 
 	k := kernel.KernelFromContext(ctx)
 	tc := k.NewThreadGroup(nil, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, k.GlobalInit().Limits())
-	_, err = createTask(ctx, "name", tc)
+	_, err = testutil.CreateTask(ctx, "name", tc)
 	if err != nil {
 		t.Fatalf("CreateTask(): %v", err)
 	}
@@ -458,7 +459,7 @@ func TestProcSelf(t *testing.T) {
 
 	k := kernel.KernelFromContext(ctx)
 	tc := k.NewThreadGroup(nil, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, k.GlobalInit().Limits())
-	task, err := createTask(ctx, "name", tc)
+	task, err := testutil.CreateTask(ctx, "name", tc)
 	if err != nil {
 		t.Fatalf("CreateTask(): %v", err)
 	}
@@ -555,7 +556,7 @@ func TestTree(t *testing.T) {
 	var tasks []*kernel.Task
 	for i := 0; i < 5; i++ {
 		tc := k.NewThreadGroup(nil, k.RootPIDNamespace(), kernel.NewSignalHandlers(), linux.SIGCHLD, k.GlobalInit().Limits())
-		task, err := createTask(uberCtx, fmt.Sprintf("name-%d", i), tc)
+		task, err := testutil.CreateTask(uberCtx, fmt.Sprintf("name-%d", i), tc)
 		if err != nil {
 			t.Fatalf("CreateTask(): %v", err)
 		}