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-rw-r--r--pkg/sentry/fsimpl/devtmpfs/BUILD33
-rw-r--r--pkg/sentry/fsimpl/devtmpfs/devtmpfs.go191
-rw-r--r--pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go122
3 files changed, 0 insertions, 346 deletions
diff --git a/pkg/sentry/fsimpl/devtmpfs/BUILD b/pkg/sentry/fsimpl/devtmpfs/BUILD
deleted file mode 100644
index aa0c2ad8c..000000000
--- a/pkg/sentry/fsimpl/devtmpfs/BUILD
+++ /dev/null
@@ -1,33 +0,0 @@
-load("//tools:defs.bzl", "go_library", "go_test")
-
-licenses(["notice"])
-
-go_library(
- name = "devtmpfs",
- srcs = ["devtmpfs.go"],
- visibility = ["//pkg/sentry:internal"],
- deps = [
- "//pkg/abi/linux",
- "//pkg/context",
- "//pkg/fspath",
- "//pkg/sentry/fsimpl/tmpfs",
- "//pkg/sentry/kernel/auth",
- "//pkg/sentry/vfs",
- "//pkg/sync",
- ],
-)
-
-go_test(
- name = "devtmpfs_test",
- size = "small",
- srcs = ["devtmpfs_test.go"],
- library = ":devtmpfs",
- deps = [
- "//pkg/abi/linux",
- "//pkg/fspath",
- "//pkg/sentry/contexttest",
- "//pkg/sentry/fsimpl/tmpfs",
- "//pkg/sentry/kernel/auth",
- "//pkg/sentry/vfs",
- ],
-)
diff --git a/pkg/sentry/fsimpl/devtmpfs/devtmpfs.go b/pkg/sentry/fsimpl/devtmpfs/devtmpfs.go
deleted file mode 100644
index abd4f24e7..000000000
--- a/pkg/sentry/fsimpl/devtmpfs/devtmpfs.go
+++ /dev/null
@@ -1,191 +0,0 @@
-// Copyright 2020 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 devtmpfs provides an implementation of /dev based on tmpfs,
-// analogous to Linux's devtmpfs.
-package devtmpfs
-
-import (
- "fmt"
-
- "gvisor.dev/gvisor/pkg/abi/linux"
- "gvisor.dev/gvisor/pkg/context"
- "gvisor.dev/gvisor/pkg/fspath"
- "gvisor.dev/gvisor/pkg/sentry/fsimpl/tmpfs"
- "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
- "gvisor.dev/gvisor/pkg/sentry/vfs"
- "gvisor.dev/gvisor/pkg/sync"
-)
-
-// Name is the default filesystem name.
-const Name = "devtmpfs"
-
-// FilesystemType implements vfs.FilesystemType.
-type FilesystemType struct {
- initOnce sync.Once
- initErr error
-
- // fs is the tmpfs filesystem that backs all mounts of this FilesystemType.
- // root is fs' root. fs and root are immutable.
- fs *vfs.Filesystem
- root *vfs.Dentry
-}
-
-// GetFilesystem implements vfs.FilesystemType.GetFilesystem.
-func (fst *FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, source string, opts vfs.GetFilesystemOptions) (*vfs.Filesystem, *vfs.Dentry, error) {
- fst.initOnce.Do(func() {
- fs, root, err := tmpfs.FilesystemType{}.GetFilesystem(ctx, vfsObj, creds, "" /* source */, vfs.GetFilesystemOptions{
- Data: "mode=0755", // opts from drivers/base/devtmpfs.c:devtmpfs_init()
- })
- if err != nil {
- fst.initErr = err
- return
- }
- fst.fs = fs
- fst.root = root
- })
- if fst.initErr != nil {
- return nil, nil, fst.initErr
- }
- fst.fs.IncRef()
- fst.root.IncRef()
- return fst.fs, fst.root, nil
-}
-
-// Accessor allows devices to create device special files in devtmpfs.
-type Accessor struct {
- vfsObj *vfs.VirtualFilesystem
- mntns *vfs.MountNamespace
- root vfs.VirtualDentry
- creds *auth.Credentials
-}
-
-// NewAccessor returns an Accessor that supports creation of device special
-// files in the devtmpfs instance registered with name fsTypeName in vfsObj.
-func NewAccessor(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, fsTypeName string) (*Accessor, error) {
- mntns, err := vfsObj.NewMountNamespace(ctx, creds, "devtmpfs" /* source */, fsTypeName, &vfs.GetFilesystemOptions{})
- if err != nil {
- return nil, err
- }
- return &Accessor{
- vfsObj: vfsObj,
- mntns: mntns,
- root: mntns.Root(),
- creds: creds,
- }, nil
-}
-
-// Release must be called when a is no longer in use.
-func (a *Accessor) Release() {
- a.root.DecRef()
- a.mntns.DecRef()
-}
-
-// accessorContext implements context.Context by extending an existing
-// context.Context with an Accessor's values for VFS-relevant state.
-type accessorContext struct {
- context.Context
- a *Accessor
-}
-
-func (a *Accessor) wrapContext(ctx context.Context) *accessorContext {
- return &accessorContext{
- Context: ctx,
- a: a,
- }
-}
-
-// Value implements context.Context.Value.
-func (ac *accessorContext) Value(key interface{}) interface{} {
- switch key {
- case vfs.CtxMountNamespace:
- ac.a.mntns.IncRef()
- return ac.a.mntns
- case vfs.CtxRoot:
- ac.a.root.IncRef()
- return ac.a.root
- default:
- return ac.Context.Value(key)
- }
-}
-
-func (a *Accessor) pathOperationAt(pathname string) *vfs.PathOperation {
- return &vfs.PathOperation{
- Root: a.root,
- Start: a.root,
- Path: fspath.Parse(pathname),
- }
-}
-
-// CreateDeviceFile creates a device special file at the given pathname in the
-// devtmpfs instance accessed by the Accessor.
-func (a *Accessor) CreateDeviceFile(ctx context.Context, pathname string, kind vfs.DeviceKind, major, minor uint32, perms uint16) error {
- mode := (linux.FileMode)(perms)
- switch kind {
- case vfs.BlockDevice:
- mode |= linux.S_IFBLK
- case vfs.CharDevice:
- mode |= linux.S_IFCHR
- default:
- panic(fmt.Sprintf("invalid vfs.DeviceKind: %v", kind))
- }
- // NOTE: Linux's devtmpfs refuses to automatically delete files it didn't
- // create, which it recognizes by storing a pointer to the kdevtmpfs struct
- // thread in struct inode::i_private. Accessor doesn't yet support deletion
- // of files at all, and probably won't as long as we don't need to support
- // kernel modules, so this is moot for now.
- return a.vfsObj.MknodAt(a.wrapContext(ctx), a.creds, a.pathOperationAt(pathname), &vfs.MknodOptions{
- Mode: mode,
- DevMajor: major,
- DevMinor: minor,
- })
-}
-
-// UserspaceInit creates symbolic links and mount points in the devtmpfs
-// instance accessed by the Accessor that are created by userspace in Linux. It
-// does not create mounts.
-func (a *Accessor) UserspaceInit(ctx context.Context) error {
- actx := a.wrapContext(ctx)
-
- // systemd: src/shared/dev-setup.c:dev_setup()
- for _, symlink := range []struct {
- source string
- target string
- }{
- // /proc/kcore is not implemented.
- {source: "fd", target: "/proc/self/fd"},
- {source: "stdin", target: "/proc/self/fd/0"},
- {source: "stdout", target: "/proc/self/fd/1"},
- {source: "stderr", target: "/proc/self/fd/2"},
- } {
- if err := a.vfsObj.SymlinkAt(actx, a.creds, a.pathOperationAt(symlink.source), symlink.target); err != nil {
- return fmt.Errorf("failed to create symlink %q => %q: %v", symlink.source, symlink.target, err)
- }
- }
-
- // systemd: src/core/mount-setup.c:mount_table
- for _, dir := range []string{
- "shm",
- "pts",
- } {
- if err := a.vfsObj.MkdirAt(actx, a.creds, a.pathOperationAt(dir), &vfs.MkdirOptions{
- // systemd: src/core/mount-setup.c:mount_one()
- Mode: 0755,
- }); err != nil {
- return fmt.Errorf("failed to create directory %q: %v", dir, err)
- }
- }
-
- return nil
-}
diff --git a/pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go b/pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go
deleted file mode 100644
index b6d52c015..000000000
--- a/pkg/sentry/fsimpl/devtmpfs/devtmpfs_test.go
+++ /dev/null
@@ -1,122 +0,0 @@
-// Copyright 2020 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 devtmpfs
-
-import (
- "testing"
-
- "gvisor.dev/gvisor/pkg/abi/linux"
- "gvisor.dev/gvisor/pkg/fspath"
- "gvisor.dev/gvisor/pkg/sentry/contexttest"
- "gvisor.dev/gvisor/pkg/sentry/fsimpl/tmpfs"
- "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
- "gvisor.dev/gvisor/pkg/sentry/vfs"
-)
-
-func TestDevtmpfs(t *testing.T) {
- ctx := contexttest.Context(t)
- creds := auth.CredentialsFromContext(ctx)
-
- vfsObj := &vfs.VirtualFilesystem{}
- if err := vfsObj.Init(); err != nil {
- t.Fatalf("VFS init: %v", err)
- }
- // Register tmpfs just so that we can have a root filesystem that isn't
- // devtmpfs.
- vfsObj.MustRegisterFilesystemType("tmpfs", tmpfs.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
- AllowUserMount: true,
- })
- vfsObj.MustRegisterFilesystemType("devtmpfs", &FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
- AllowUserMount: true,
- })
-
- // Create a test mount namespace with devtmpfs mounted at "/dev".
- const devPath = "/dev"
- mntns, err := vfsObj.NewMountNamespace(ctx, creds, "tmpfs" /* source */, "tmpfs" /* fsTypeName */, &vfs.GetFilesystemOptions{})
- if err != nil {
- t.Fatalf("failed to create tmpfs root mount: %v", err)
- }
- defer mntns.DecRef()
- root := mntns.Root()
- defer root.DecRef()
- devpop := vfs.PathOperation{
- Root: root,
- Start: root,
- Path: fspath.Parse(devPath),
- }
- if err := vfsObj.MkdirAt(ctx, creds, &devpop, &vfs.MkdirOptions{
- Mode: 0755,
- }); err != nil {
- t.Fatalf("failed to create mount point: %v", err)
- }
- if err := vfsObj.MountAt(ctx, creds, "devtmpfs" /* source */, &devpop, "devtmpfs" /* fsTypeName */, &vfs.MountOptions{}); err != nil {
- t.Fatalf("failed to mount devtmpfs: %v", err)
- }
-
- a, err := NewAccessor(ctx, vfsObj, creds, "devtmpfs")
- if err != nil {
- t.Fatalf("failed to create devtmpfs.Accessor: %v", err)
- }
- defer a.Release()
-
- // Create "userspace-initialized" files using a devtmpfs.Accessor.
- if err := a.UserspaceInit(ctx); err != nil {
- t.Fatalf("failed to userspace-initialize devtmpfs: %v", err)
- }
- // Created files should be visible in the test mount namespace.
- abspath := devPath + "/fd"
- target, err := vfsObj.ReadlinkAt(ctx, creds, &vfs.PathOperation{
- Root: root,
- Start: root,
- Path: fspath.Parse(abspath),
- })
- if want := "/proc/self/fd"; err != nil || target != want {
- t.Fatalf("readlink(%q): got (%q, %v), wanted (%q, nil)", abspath, target, err, want)
- }
-
- // Create a dummy device special file using a devtmpfs.Accessor.
- const (
- pathInDev = "dummy"
- kind = vfs.CharDevice
- major = 12
- minor = 34
- perms = 0600
- wantMode = linux.S_IFCHR | perms
- )
- if err := a.CreateDeviceFile(ctx, pathInDev, kind, major, minor, perms); err != nil {
- t.Fatalf("failed to create device file: %v", err)
- }
- // The device special file should be visible in the test mount namespace.
- abspath = devPath + "/" + pathInDev
- stat, err := vfsObj.StatAt(ctx, creds, &vfs.PathOperation{
- Root: root,
- Start: root,
- Path: fspath.Parse(abspath),
- }, &vfs.StatOptions{
- Mask: linux.STATX_TYPE | linux.STATX_MODE,
- })
- if err != nil {
- t.Fatalf("failed to stat device file at %q: %v", abspath, err)
- }
- if stat.Mode != wantMode {
- t.Errorf("device file mode: got %v, wanted %v", stat.Mode, wantMode)
- }
- if stat.RdevMajor != major {
- t.Errorf("major device number: got %v, wanted %v", stat.RdevMajor, major)
- }
- if stat.RdevMinor != minor {
- t.Errorf("minor device number: got %v, wanted %v", stat.RdevMinor, minor)
- }
-}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 21:02:30 +0000