1 files changed, 180 insertions, 0 deletions
diff --git a/pkg/sentry/fsimpl/testutil/kernel.go b/pkg/sentry/fsimpl/testutil/kernel.go
new file mode 100644
index 000000000..1813269e0
--- /dev/null
+++ b/pkg/sentry/fsimpl/testutil/kernel.go
@@ -0,0 +1,180 @@
+// 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 testutil
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"runtime"
+
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/cpuid"
+	"gvisor.dev/gvisor/pkg/fspath"
+	"gvisor.dev/gvisor/pkg/memutil"
+	"gvisor.dev/gvisor/pkg/sentry/fsbridge"
+	"gvisor.dev/gvisor/pkg/sentry/fsimpl/tmpfs"
+	"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/mm"
+	"gvisor.dev/gvisor/pkg/sentry/pgalloc"
+	"gvisor.dev/gvisor/pkg/sentry/platform"
+	"gvisor.dev/gvisor/pkg/sentry/time"
+	"gvisor.dev/gvisor/pkg/sentry/vfs"
+
+	// 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)
+	}
+
+	kernel.VFS2Enabled = true
+	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(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)
+	}
+
+	k.VFS().MustRegisterFilesystemType(tmpfs.Name, &tmpfs.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+		AllowUserList:  true,
+	})
+
+	ls, err := limits.NewLinuxLimitSet()
+	if err != nil {
+		return nil, err
+	}
+	tg := k.NewThreadGroup(nil, 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, mntns *vfs.MountNamespace, root, cwd vfs.VirtualDentry) (*kernel.Task, error) {
+	k := kernel.KernelFromContext(ctx)
+	if k == nil {
+		return nil, fmt.Errorf("cannot find kernel from context")
+	}
+
+	exe, err := newFakeExecutable(ctx, k.VFS(), auth.CredentialsFromContext(ctx), root)
+	if err != nil {
+		return nil, err
+	}
+	m := mm.NewMemoryManager(k, k, k.SleepForAddressSpaceActivation)
+	m.SetExecutable(ctx, fsbridge.NewVFSFile(exe))
+
+	config := &kernel.TaskConfig{
+		Kernel:                  k,
+		ThreadGroup:             tc,
+		TaskContext:             &kernel.TaskContext{Name: name, MemoryManager: m},
+		Credentials:             auth.CredentialsFromContext(ctx),
+		NetworkNamespace:        k.RootNetworkNamespace(),
+		AllowedCPUMask:          sched.NewFullCPUSet(k.ApplicationCores()),
+		UTSNamespace:            kernel.UTSNamespaceFromContext(ctx),
+		IPCNamespace:            kernel.IPCNamespaceFromContext(ctx),
+		AbstractSocketNamespace: kernel.NewAbstractSocketNamespace(),
+		MountNamespaceVFS2:      mntns,
+		FSContext:               kernel.NewFSContextVFS2(root, cwd, 0022),
+		FDTable:                 k.NewFDTable(),
+	}
+	return k.TaskSet().NewTask(config)
+}
+
+func newFakeExecutable(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, root vfs.VirtualDentry) (*vfs.FileDescription, error) {
+	const name = "executable"
+	pop := &vfs.PathOperation{
+		Root:  root,
+		Start: root,
+		Path:  fspath.Parse(name),
+	}
+	opts := &vfs.OpenOptions{
+		Flags: linux.O_RDONLY | linux.O_CREAT,
+		Mode:  0777,
+	}
+	return vfsObj.OpenAt(ctx, creds, pop, opts)
+}
+
+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
+}