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author | kevin.xu <cming.xu@gmail.com> | 2020-04-27 21:51:31 +0800 |
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committer | GitHub <noreply@github.com> | 2020-04-27 21:51:31 +0800 |
commit | e896ca54db67524afc20b644d43c72185e72dc0e (patch) | |
tree | 2a16f3a62a5cafd098f1f028c621f1b655589d69 /pkg/sentry/fsimpl/testutil/kernel.go | |
parent | 1f19624fa127d7d59cabe29593cc80b7fe6c81f8 (diff) | |
parent | 3c67754663f424f2ebbc0ff2a4c80e30618d5355 (diff) |
Merge pull request #1 from google/master
catch up
Diffstat (limited to 'pkg/sentry/fsimpl/testutil/kernel.go')
-rw-r--r-- | pkg/sentry/fsimpl/testutil/kernel.go | 180 |
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..c16a36cdb --- /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) + } + + 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) + } + + kernel.VFS2Enabled = true + + if err := k.VFS().Init(); err != nil { + return nil, fmt.Errorf("VFS init: %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) + 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(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 +} |