Initial procfs implementation in VFSv2

Updates #1195

PiperOrigin-RevId: 287227722

3 files changed, 11 insertions, 6 deletions

diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go
index bd3fb4c03..8653d2f63 100644
--- a/pkg/sentry/kernel/kernel.go
+++ b/pkg/sentry/kernel/kernel.go
@@ -762,7 +762,7 @@ func (k *Kernel) CreateProcess(args CreateProcessArgs) (*ThreadGroup, ThreadID,
 		mounts.IncRef()
 	}
 
-	tg := k.newThreadGroup(mounts, args.PIDNamespace, NewSignalHandlers(), linux.SIGCHLD, args.Limits, k.monotonicClock)
+	tg := k.NewThreadGroup(mounts, args.PIDNamespace, NewSignalHandlers(), linux.SIGCHLD, args.Limits)
 	ctx := args.NewContext(k)
 
 	// Get the root directory from the MountNamespace.
@@ -1191,6 +1191,11 @@ func (k *Kernel) GlobalInit() *ThreadGroup {
 	return k.globalInit
 }
 
+// TestOnly_SetGlobalInit sets the thread group with ID 1 in the root PID namespace.
+func (k *Kernel) TestOnly_SetGlobalInit(tg *ThreadGroup) {
+	k.globalInit = tg
+}
+
 // ApplicationCores returns the number of CPUs visible to sandboxed
 // applications.
 func (k *Kernel) ApplicationCores() uint {
diff --git a/pkg/sentry/kernel/task_clone.go b/pkg/sentry/kernel/task_clone.go
index 3eadfedb4..5f3589493 100644
--- a/pkg/sentry/kernel/task_clone.go
+++ b/pkg/sentry/kernel/task_clone.go
@@ -243,7 +243,7 @@ func (t *Task) Clone(opts *CloneOptions) (ThreadID, *SyscallControl, error) {
 		if opts.NewSignalHandlers {
 			sh = sh.Fork()
 		}
-		tg = t.k.newThreadGroup(tg.mounts, pidns, sh, opts.TerminationSignal, tg.limits.GetCopy(), t.k.monotonicClock)
+		tg = t.k.NewThreadGroup(tg.mounts, pidns, sh, opts.TerminationSignal, tg.limits.GetCopy())
 	}
 
 	cfg := &TaskConfig{
diff --git a/pkg/sentry/kernel/thread_group.go b/pkg/sentry/kernel/thread_group.go
index 72568d296..0cded73f6 100644
--- a/pkg/sentry/kernel/thread_group.go
+++ b/pkg/sentry/kernel/thread_group.go
@@ -256,20 +256,20 @@ type ThreadGroup struct {
 	tty *TTY
 }
 
-// newThreadGroup returns a new, empty thread group in PID namespace ns. The
+// NewThreadGroup returns a new, empty thread group in PID namespace ns. The
 // thread group leader will send its parent terminationSignal when it exits.
 // The new thread group isn't visible to the system until a task has been
 // created inside of it by a successful call to TaskSet.NewTask.
-func (k *Kernel) newThreadGroup(mounts *fs.MountNamespace, ns *PIDNamespace, sh *SignalHandlers, terminationSignal linux.Signal, limits *limits.LimitSet, monotonicClock *timekeeperClock) *ThreadGroup {
+func (k *Kernel) NewThreadGroup(mntns *fs.MountNamespace, pidns *PIDNamespace, sh *SignalHandlers, terminationSignal linux.Signal, limits *limits.LimitSet) *ThreadGroup {
 	tg := &ThreadGroup{
 		threadGroupNode: threadGroupNode{
-			pidns: ns,
+			pidns: pidns,
 		},
 		signalHandlers:    sh,
 		terminationSignal: terminationSignal,
 		ioUsage:           &usage.IO{},
 		limits:            limits,
-		mounts:            mounts,
+		mounts:            mntns,
 	}
 	tg.itimerRealTimer = ktime.NewTimer(k.monotonicClock, &itimerRealListener{tg: tg})
 	tg.timers = make(map[linux.TimerID]*IntervalTimer)