2 files changed, 23 insertions, 8 deletions
diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go
index 38b49cba2..4c2d48e65 100644
--- a/pkg/sentry/kernel/kernel.go
+++ b/pkg/sentry/kernel/kernel.go
@@ -240,6 +240,9 @@ type InitKernelArgs struct {
 
 	// RootAbstractSocketNamespace is the root Abstract Socket namespace.
 	RootAbstractSocketNamespace *AbstractSocketNamespace
+
+	// PIDNamespace is the root PID namespace.
+	PIDNamespace *PIDNamespace
 }
 
 // Init initialize the Kernel with no tasks.
@@ -262,7 +265,7 @@ func (k *Kernel) Init(args InitKernelArgs) error {
 
 	k.featureSet = args.FeatureSet
 	k.timekeeper = args.Timekeeper
-	k.tasks = newTaskSet()
+	k.tasks = newTaskSet(args.PIDNamespace)
 	k.rootUserNamespace = args.RootUserNamespace
 	k.rootUTSNamespace = args.RootUTSNamespace
 	k.rootIPCNamespace = args.RootIPCNamespace
@@ -622,6 +625,9 @@ type CreateProcessArgs struct {
 	// IPCNamespace is the initial IPC namespace.
 	IPCNamespace *IPCNamespace
 
+	// PIDNamespace is the initial PID Namespace.
+	PIDNamespace *PIDNamespace
+
 	// AbstractSocketNamespace is the initial Abstract Socket namespace.
 	AbstractSocketNamespace *AbstractSocketNamespace
 
@@ -668,9 +674,7 @@ func (ctx *createProcessContext) Value(key interface{}) interface{} {
 	case CtxKernel:
 		return ctx.k
 	case CtxPIDNamespace:
-		// "The new task ... is in the root PID namespace." -
-		// Kernel.CreateProcess
-		return ctx.k.tasks.Root
+		return ctx.args.PIDNamespace
 	case CtxUTSNamespace:
 		return ctx.args.UTSNamespace
 	case CtxIPCNamespace:
@@ -745,7 +749,7 @@ func (k *Kernel) CreateProcess(args CreateProcessArgs) (*ThreadGroup, ThreadID,
 		mounts.IncRef()
 	}
 
-	tg := k.newThreadGroup(mounts, k.tasks.Root, NewSignalHandlers(), linux.SIGCHLD, args.Limits, k.monotonicClock)
+	tg := k.newThreadGroup(mounts, args.PIDNamespace, NewSignalHandlers(), linux.SIGCHLD, args.Limits, k.monotonicClock)
 	ctx := args.NewContext(k)
 
 	// Grab the root directory.
@@ -1018,6 +1022,11 @@ func (k *Kernel) RootIPCNamespace() *IPCNamespace {
 	return k.rootIPCNamespace
 }
 
+// RootPIDNamespace returns the root PIDNamespace.
+func (k *Kernel) RootPIDNamespace() *PIDNamespace {
+	return k.tasks.Root
+}
+
 // RootAbstractSocketNamespace returns the root AbstractSocketNamespace.
 func (k *Kernel) RootAbstractSocketNamespace() *AbstractSocketNamespace {
 	return k.rootAbstractSocketNamespace
diff --git a/pkg/sentry/kernel/threads.go b/pkg/sentry/kernel/threads.go
index b21b182fc..8267929a6 100644
--- a/pkg/sentry/kernel/threads.go
+++ b/pkg/sentry/kernel/threads.go
@@ -90,9 +90,9 @@ type TaskSet struct {
 }
 
 // newTaskSet returns a new, empty TaskSet.
-func newTaskSet() *TaskSet {
-	ts := &TaskSet{}
-	ts.Root = newPIDNamespace(ts, nil /* parent */, auth.NewRootUserNamespace())
+func newTaskSet(pidns *PIDNamespace) *TaskSet {
+	ts := &TaskSet{Root: pidns}
+	pidns.owner = ts
 	return ts
 }
 
@@ -186,6 +186,12 @@ func newPIDNamespace(ts *TaskSet, parent *PIDNamespace, userns *auth.UserNamespa
 	}
 }
 
+// NewRootPIDNamespace creates the root PID namespace. 'owner' is not available
+// yet when root namespace is created and must be set by caller.
+func NewRootPIDNamespace(userns *auth.UserNamespace) *PIDNamespace {
+	return newPIDNamespace(nil, nil, userns)
+}
+
 // NewChild returns a new, empty PID namespace that is a child of ns. Authority
 // over the new PID namespace is controlled by userns.
 func (ns *PIDNamespace) NewChild(userns *auth.UserNamespace) *PIDNamespace {