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Diffstat (limited to 'pkg/sentry/kernel/kernel.go')
-rw-r--r--pkg/sentry/kernel/kernel.go152
1 files changed, 136 insertions, 16 deletions
diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go
index 1d627564f..c91b9dce2 100644
--- a/pkg/sentry/kernel/kernel.go
+++ b/pkg/sentry/kernel/kernel.go
@@ -50,6 +50,8 @@ import (
"gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sentry/fs/timerfd"
"gvisor.dev/gvisor/pkg/sentry/fsbridge"
+ "gvisor.dev/gvisor/pkg/sentry/fsimpl/pipefs"
+ "gvisor.dev/gvisor/pkg/sentry/fsimpl/sockfs"
"gvisor.dev/gvisor/pkg/sentry/hostcpu"
"gvisor.dev/gvisor/pkg/sentry/inet"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
@@ -248,6 +250,22 @@ type Kernel struct {
// VFS keeps the filesystem state used across the kernel.
vfs vfs.VirtualFilesystem
+ // hostMount is the Mount used for file descriptors that were imported
+ // from the host.
+ hostMount *vfs.Mount
+
+ // pipeMount is the Mount used for pipes created by the pipe() and pipe2()
+ // syscalls (as opposed to named pipes created by mknod()).
+ pipeMount *vfs.Mount
+
+ // socketMount is the Mount used for sockets created by the socket() and
+ // socketpair() syscalls. There are several cases where a socket dentry will
+ // not be contained in socketMount:
+ // 1. Socket files created by mknod()
+ // 2. Socket fds imported from the host (Kernel.hostMount is used for these)
+ // 3. Socket files created by binding Unix sockets to a file path
+ socketMount *vfs.Mount
+
// If set to true, report address space activation waits as if the task is in
// external wait so that the watchdog doesn't report the task stuck.
SleepForAddressSpaceActivation bool
@@ -348,6 +366,29 @@ func (k *Kernel) Init(args InitKernelArgs) error {
k.monotonicClock = &timekeeperClock{tk: args.Timekeeper, c: sentrytime.Monotonic}
k.futexes = futex.NewManager()
k.netlinkPorts = port.New()
+
+ if VFS2Enabled {
+ if err := k.vfs.Init(); err != nil {
+ return fmt.Errorf("failed to initialize VFS: %v", err)
+ }
+
+ pipeFilesystem := pipefs.NewFilesystem(&k.vfs)
+ defer pipeFilesystem.DecRef()
+ pipeMount, err := k.vfs.NewDisconnectedMount(pipeFilesystem, nil, &vfs.MountOptions{})
+ if err != nil {
+ return fmt.Errorf("failed to create pipefs mount: %v", err)
+ }
+ k.pipeMount = pipeMount
+
+ socketFilesystem := sockfs.NewFilesystem(&k.vfs)
+ defer socketFilesystem.DecRef()
+ socketMount, err := k.vfs.NewDisconnectedMount(socketFilesystem, nil, &vfs.MountOptions{})
+ if err != nil {
+ return fmt.Errorf("failed to create sockfs mount: %v", err)
+ }
+ k.socketMount = socketMount
+ }
+
return nil
}
@@ -467,6 +508,11 @@ func (k *Kernel) flushMountSourceRefs() error {
//
// Precondition: Must be called with the kernel paused.
func (ts *TaskSet) forEachFDPaused(f func(*fs.File, *vfs.FileDescription) error) (err error) {
+ // TODO(gvisor.dev/issue/1663): Add save support for VFS2.
+ if VFS2Enabled {
+ return nil
+ }
+
ts.mu.RLock()
defer ts.mu.RUnlock()
for t := range ts.Root.tids {
@@ -484,7 +530,7 @@ func (ts *TaskSet) forEachFDPaused(f func(*fs.File, *vfs.FileDescription) error)
}
func (ts *TaskSet) flushWritesToFiles(ctx context.Context) error {
- // TODO(gvisor.dev/issues/1663): Add save support for VFS2.
+ // TODO(gvisor.dev/issue/1663): Add save support for VFS2.
return ts.forEachFDPaused(func(file *fs.File, _ *vfs.FileDescription) error {
if flags := file.Flags(); !flags.Write {
return nil
@@ -533,17 +579,32 @@ func (k *Kernel) invalidateUnsavableMappings(ctx context.Context) error {
}
func (ts *TaskSet) unregisterEpollWaiters() {
+ // TODO(gvisor.dev/issue/1663): Add save support for VFS2.
+ if VFS2Enabled {
+ return
+ }
+
ts.mu.RLock()
defer ts.mu.RUnlock()
+
+ // Tasks that belong to the same process could potentially point to the
+ // same FDTable. So we retain a map of processed ones to avoid
+ // processing the same FDTable multiple times.
+ processed := make(map[*FDTable]struct{})
for t := range ts.Root.tids {
// We can skip locking Task.mu here since the kernel is paused.
- if t.fdTable != nil {
- t.fdTable.forEach(func(_ int32, file *fs.File, _ *vfs.FileDescription, _ FDFlags) {
- if e, ok := file.FileOperations.(*epoll.EventPoll); ok {
- e.UnregisterEpollWaiters()
- }
- })
+ if t.fdTable == nil {
+ continue
+ }
+ if _, ok := processed[t.fdTable]; ok {
+ continue
}
+ t.fdTable.forEach(func(_ int32, file *fs.File, _ *vfs.FileDescription, _ FDFlags) {
+ if e, ok := file.FileOperations.(*epoll.EventPoll); ok {
+ e.UnregisterEpollWaiters()
+ }
+ })
+ processed[t.fdTable] = struct{}{}
}
}
@@ -1005,9 +1066,15 @@ func (k *Kernel) pauseTimeLocked() {
// This means we'll iterate FDTables shared by multiple tasks repeatedly,
// but ktime.Timer.Pause is idempotent so this is harmless.
if t.fdTable != nil {
- t.fdTable.forEach(func(_ int32, file *fs.File, _ *vfs.FileDescription, _ FDFlags) {
- if tfd, ok := file.FileOperations.(*timerfd.TimerOperations); ok {
- tfd.PauseTimer()
+ t.fdTable.forEach(func(_ int32, file *fs.File, fd *vfs.FileDescription, _ FDFlags) {
+ if VFS2Enabled {
+ if tfd, ok := fd.Impl().(*vfs.TimerFileDescription); ok {
+ tfd.PauseTimer()
+ }
+ } else {
+ if tfd, ok := file.FileOperations.(*timerfd.TimerOperations); ok {
+ tfd.PauseTimer()
+ }
}
})
}
@@ -1035,9 +1102,15 @@ func (k *Kernel) resumeTimeLocked() {
}
}
if t.fdTable != nil {
- t.fdTable.forEach(func(_ int32, file *fs.File, _ *vfs.FileDescription, _ FDFlags) {
- if tfd, ok := file.FileOperations.(*timerfd.TimerOperations); ok {
- tfd.ResumeTimer()
+ t.fdTable.forEach(func(_ int32, file *fs.File, fd *vfs.FileDescription, _ FDFlags) {
+ if VFS2Enabled {
+ if tfd, ok := fd.Impl().(*vfs.TimerFileDescription); ok {
+ tfd.ResumeTimer()
+ }
+ } else {
+ if tfd, ok := file.FileOperations.(*timerfd.TimerOperations); ok {
+ tfd.ResumeTimer()
+ }
}
})
}
@@ -1400,9 +1473,10 @@ func (k *Kernel) SupervisorContext() context.Context {
// +stateify savable
type SocketEntry struct {
socketEntry
- k *Kernel
- Sock *refs.WeakRef
- ID uint64 // Socket table entry number.
+ k *Kernel
+ Sock *refs.WeakRef
+ SockVFS2 *vfs.FileDescription
+ ID uint64 // Socket table entry number.
}
// WeakRefGone implements refs.WeakRefUser.WeakRefGone.
@@ -1425,7 +1499,30 @@ func (k *Kernel) RecordSocket(sock *fs.File) {
k.extMu.Unlock()
}
+// RecordSocketVFS2 adds a VFS2 socket to the system-wide socket table for
+// tracking.
+//
+// Precondition: Caller must hold a reference to sock.
+//
+// Note that the socket table will not hold a reference on the
+// vfs.FileDescription, because we do not support weak refs on VFS2 files.
+func (k *Kernel) RecordSocketVFS2(sock *vfs.FileDescription) {
+ k.extMu.Lock()
+ id := k.nextSocketEntry
+ k.nextSocketEntry++
+ s := &SocketEntry{
+ k: k,
+ ID: id,
+ SockVFS2: sock,
+ }
+ k.sockets.PushBack(s)
+ k.extMu.Unlock()
+}
+
// ListSockets returns a snapshot of all sockets.
+//
+// Callers of ListSockets() in VFS2 should use SocketEntry.SockVFS2.TryIncRef()
+// to get a reference on a socket in the table.
func (k *Kernel) ListSockets() []*SocketEntry {
k.extMu.Lock()
var socks []*SocketEntry
@@ -1533,3 +1630,26 @@ func (k *Kernel) EmitUnimplementedEvent(ctx context.Context) {
func (k *Kernel) VFS() *vfs.VirtualFilesystem {
return &k.vfs
}
+
+// SetHostMount sets the hostfs mount.
+func (k *Kernel) SetHostMount(mnt *vfs.Mount) {
+ if k.hostMount != nil {
+ panic("Kernel.hostMount cannot be set more than once")
+ }
+ k.hostMount = mnt
+}
+
+// HostMount returns the hostfs mount.
+func (k *Kernel) HostMount() *vfs.Mount {
+ return k.hostMount
+}
+
+// PipeMount returns the pipefs mount.
+func (k *Kernel) PipeMount() *vfs.Mount {
+ return k.pipeMount
+}
+
+// SocketMount returns the sockfs mount.
+func (k *Kernel) SocketMount() *vfs.Mount {
+ return k.socketMount
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-03 23:19:41 +0000