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-rw-r--r--pkg/sentry/fsimpl/sys/BUILD34
-rw-r--r--pkg/sentry/fsimpl/sys/sys.go159
-rw-r--r--pkg/sentry/fsimpl/sys/sys_test.go89
3 files changed, 282 insertions, 0 deletions
diff --git a/pkg/sentry/fsimpl/sys/BUILD b/pkg/sentry/fsimpl/sys/BUILD
new file mode 100644
index 000000000..1b548ccd4
--- /dev/null
+++ b/pkg/sentry/fsimpl/sys/BUILD
@@ -0,0 +1,34 @@
+load("//tools:defs.bzl", "go_library", "go_test")
+
+licenses(["notice"])
+
+go_library(
+ name = "sys",
+ srcs = [
+ "sys.go",
+ ],
+ visibility = ["//pkg/sentry:internal"],
+ deps = [
+ "//pkg/abi/linux",
+ "//pkg/context",
+ "//pkg/sentry/fsimpl/kernfs",
+ "//pkg/sentry/kernel",
+ "//pkg/sentry/kernel/auth",
+ "//pkg/sentry/vfs",
+ "//pkg/syserror",
+ ],
+)
+
+go_test(
+ name = "sys_test",
+ srcs = ["sys_test.go"],
+ deps = [
+ ":sys",
+ "//pkg/abi/linux",
+ "//pkg/sentry/fsimpl/testutil",
+ "//pkg/sentry/kernel",
+ "//pkg/sentry/kernel/auth",
+ "//pkg/sentry/vfs",
+ "@com_github_google_go_cmp//cmp:go_default_library",
+ ],
+)
diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go
new file mode 100644
index 000000000..0401726b6
--- /dev/null
+++ b/pkg/sentry/fsimpl/sys/sys.go
@@ -0,0 +1,159 @@
+// 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 sys implements sysfs.
+package sys
+
+import (
+ "bytes"
+ "fmt"
+
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+)
+
+// Name is the default filesystem name.
+const Name = "sysfs"
+const defaultSysDirMode = linux.FileMode(0755)
+
+// FilesystemType implements vfs.FilesystemType.
+type FilesystemType struct{}
+
+// filesystem implements vfs.FilesystemImpl.
+type filesystem struct {
+ kernfs.Filesystem
+
+ devMinor uint32
+}
+
+// Name implements vfs.FilesystemType.Name.
+func (FilesystemType) Name() string {
+ return Name
+}
+
+// GetFilesystem implements vfs.FilesystemType.GetFilesystem.
+func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, source string, opts vfs.GetFilesystemOptions) (*vfs.Filesystem, *vfs.Dentry, error) {
+ devMinor, err := vfsObj.GetAnonBlockDevMinor()
+ if err != nil {
+ return nil, nil, err
+ }
+
+ fs := &filesystem{
+ devMinor: devMinor,
+ }
+ fs.VFSFilesystem().Init(vfsObj, &fsType, fs)
+
+ root := fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{
+ "block": fs.newDir(creds, defaultSysDirMode, nil),
+ "bus": fs.newDir(creds, defaultSysDirMode, nil),
+ "class": fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{
+ "power_supply": fs.newDir(creds, defaultSysDirMode, nil),
+ }),
+ "dev": fs.newDir(creds, defaultSysDirMode, nil),
+ "devices": fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{
+ "system": fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{
+ "cpu": cpuDir(ctx, fs, creds),
+ }),
+ }),
+ "firmware": fs.newDir(creds, defaultSysDirMode, nil),
+ "fs": fs.newDir(creds, defaultSysDirMode, nil),
+ "kernel": fs.newDir(creds, defaultSysDirMode, nil),
+ "module": fs.newDir(creds, defaultSysDirMode, nil),
+ "power": fs.newDir(creds, defaultSysDirMode, nil),
+ })
+ return fs.VFSFilesystem(), root.VFSDentry(), nil
+}
+
+func cpuDir(ctx context.Context, fs *filesystem, creds *auth.Credentials) *kernfs.Dentry {
+ k := kernel.KernelFromContext(ctx)
+ maxCPUCores := k.ApplicationCores()
+ children := map[string]*kernfs.Dentry{
+ "online": fs.newCPUFile(creds, maxCPUCores, linux.FileMode(0444)),
+ "possible": fs.newCPUFile(creds, maxCPUCores, linux.FileMode(0444)),
+ "present": fs.newCPUFile(creds, maxCPUCores, linux.FileMode(0444)),
+ }
+ for i := uint(0); i < maxCPUCores; i++ {
+ children[fmt.Sprintf("cpu%d", i)] = fs.newDir(creds, linux.FileMode(0555), nil)
+ }
+ return fs.newDir(creds, defaultSysDirMode, children)
+}
+
+// Release implements vfs.FilesystemImpl.Release.
+func (fs *filesystem) Release(ctx context.Context) {
+ fs.Filesystem.VFSFilesystem().VirtualFilesystem().PutAnonBlockDevMinor(fs.devMinor)
+ fs.Filesystem.Release(ctx)
+}
+
+// dir implements kernfs.Inode.
+type dir struct {
+ kernfs.InodeAttrs
+ kernfs.InodeNoDynamicLookup
+ kernfs.InodeNotSymlink
+ kernfs.InodeDirectoryNoNewChildren
+ kernfs.OrderedChildren
+
+ locks vfs.FileLocks
+
+ dentry kernfs.Dentry
+}
+
+func (fs *filesystem) newDir(creds *auth.Credentials, mode linux.FileMode, contents map[string]*kernfs.Dentry) *kernfs.Dentry {
+ d := &dir{}
+ d.InodeAttrs.Init(creds, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), linux.ModeDirectory|0755)
+ d.OrderedChildren.Init(kernfs.OrderedChildrenOptions{})
+ d.dentry.Init(d)
+
+ d.IncLinks(d.OrderedChildren.Populate(&d.dentry, contents))
+
+ return &d.dentry
+}
+
+// SetStat implements Inode.SetStat not allowing inode attributes to be changed.
+func (*dir) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.SetStatOptions) error {
+ return syserror.EPERM
+}
+
+// Open implements kernfs.Inode.Open.
+func (d *dir) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
+ fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &d.locks, &opts)
+ if err != nil {
+ return nil, err
+ }
+ return fd.VFSFileDescription(), nil
+}
+
+// cpuFile implements kernfs.Inode.
+type cpuFile struct {
+ kernfs.DynamicBytesFile
+ maxCores uint
+}
+
+// Generate implements vfs.DynamicBytesSource.Generate.
+func (c *cpuFile) Generate(ctx context.Context, buf *bytes.Buffer) error {
+ fmt.Fprintf(buf, "0-%d\n", c.maxCores-1)
+ return nil
+}
+
+func (fs *filesystem) newCPUFile(creds *auth.Credentials, maxCores uint, mode linux.FileMode) *kernfs.Dentry {
+ c := &cpuFile{maxCores: maxCores}
+ c.DynamicBytesFile.Init(creds, linux.UNNAMED_MAJOR, fs.devMinor, fs.NextIno(), c, mode)
+ d := &kernfs.Dentry{}
+ d.Init(c)
+ return d
+}
diff --git a/pkg/sentry/fsimpl/sys/sys_test.go b/pkg/sentry/fsimpl/sys/sys_test.go
new file mode 100644
index 000000000..9fd38b295
--- /dev/null
+++ b/pkg/sentry/fsimpl/sys/sys_test.go
@@ -0,0 +1,89 @@
+// 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 sys_test
+
+import (
+ "fmt"
+ "testing"
+
+ "github.com/google/go-cmp/cmp"
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/fsimpl/sys"
+ "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/vfs"
+)
+
+func newTestSystem(t *testing.T) *testutil.System {
+ k, err := testutil.Boot()
+ if err != nil {
+ t.Fatalf("Failed to create test kernel: %v", err)
+ }
+ ctx := k.SupervisorContext()
+ creds := auth.CredentialsFromContext(ctx)
+ k.VFS().MustRegisterFilesystemType(sys.Name, sys.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+ AllowUserMount: true,
+ })
+
+ mns, err := k.VFS().NewMountNamespace(ctx, creds, "", sys.Name, &vfs.GetFilesystemOptions{})
+ if err != nil {
+ t.Fatalf("Failed to create new mount namespace: %v", err)
+ }
+ return testutil.NewSystem(ctx, t, k.VFS(), mns)
+}
+
+func TestReadCPUFile(t *testing.T) {
+ s := newTestSystem(t)
+ defer s.Destroy()
+ k := kernel.KernelFromContext(s.Ctx)
+ maxCPUCores := k.ApplicationCores()
+
+ expected := fmt.Sprintf("0-%d\n", maxCPUCores-1)
+
+ for _, fname := range []string{"online", "possible", "present"} {
+ pop := s.PathOpAtRoot(fmt.Sprintf("devices/system/cpu/%s", fname))
+ fd, err := s.VFS.OpenAt(s.Ctx, s.Creds, pop, &vfs.OpenOptions{})
+ if err != nil {
+ t.Fatalf("OpenAt(pop:%+v) = %+v failed: %v", pop, fd, err)
+ }
+ defer fd.DecRef(s.Ctx)
+ content, err := s.ReadToEnd(fd)
+ if err != nil {
+ t.Fatalf("Read failed: %v", err)
+ }
+ if diff := cmp.Diff(expected, content); diff != "" {
+ t.Fatalf("Read returned unexpected data:\n--- want\n+++ got\n%v", diff)
+ }
+ }
+}
+
+func TestSysRootContainsExpectedEntries(t *testing.T) {
+ s := newTestSystem(t)
+ defer s.Destroy()
+ pop := s.PathOpAtRoot("/")
+ s.AssertAllDirentTypes(s.ListDirents(pop), map[string]testutil.DirentType{
+ "block": linux.DT_DIR,
+ "bus": linux.DT_DIR,
+ "class": linux.DT_DIR,
+ "dev": linux.DT_DIR,
+ "devices": linux.DT_DIR,
+ "firmware": linux.DT_DIR,
+ "fs": linux.DT_DIR,
+ "kernel": linux.DT_DIR,
+ "module": linux.DT_DIR,
+ "power": linux.DT_DIR,
+ })
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-17 06:39:48 +0000