1 files changed, 43 insertions, 6 deletions

diff --git a/pkg/sentry/kernel/task.go b/pkg/sentry/kernel/task.go
index f48247c94..037971393 100644
--- a/pkg/sentry/kernel/task.go
+++ b/pkg/sentry/kernel/task.go
@@ -68,6 +68,21 @@ type Task struct {
 	// runState is exclusive to the task goroutine.
 	runState taskRunState
 
+	// taskWorkCount represents the current size of the task work queue. It is
+	// used to avoid acquiring taskWorkMu when the queue is empty.
+	//
+	// Must accessed with atomic memory operations.
+	taskWorkCount int32
+
+	// taskWorkMu protects taskWork.
+	taskWorkMu sync.Mutex `state:"nosave"`
+
+	// taskWork is a queue of work to be executed before resuming user execution.
+	// It is similar to the task_work mechanism in Linux.
+	//
+	// taskWork is exclusive to the task goroutine.
+	taskWork []TaskWorker
+
 	// haveSyscallReturn is true if tc.Arch().Return() represents a value
 	// returned by a syscall (or set by ptrace after a syscall).
 	//
@@ -550,11 +565,20 @@ type Task struct {
 	// futexWaiter is exclusive to the task goroutine.
 	futexWaiter *futex.Waiter `state:"nosave"`
 
+	// robustList is a pointer to the head of the tasks's robust futex
+	// list.
+	robustList usermem.Addr
+
 	// startTime is the real time at which the task started. It is set when
 	// a Task is created or invokes execve(2).
 	//
 	// startTime is protected by mu.
 	startTime ktime.Time
+
+	// kcov is the kcov instance providing code coverage owned by this task.
+	//
+	// kcov is exclusive to the task goroutine.
+	kcov *Kcov
 }
 
 func (t *Task) savePtraceTracer() *Task {
@@ -632,7 +656,9 @@ func (t *Task) Value(key interface{}) interface{} {
 	case CtxUTSNamespace:
 		return t.utsns
 	case CtxIPCNamespace:
-		return t.ipcns
+		ipcns := t.IPCNamespace()
+		ipcns.IncRef()
+		return ipcns
 	case CtxTask:
 		return t
 	case auth.CtxCredentials:
@@ -711,17 +737,16 @@ func (t *Task) SyscallRestartBlock() SyscallRestartBlock {
 func (t *Task) IsChrooted() bool {
 	if VFS2Enabled {
 		realRoot := t.mountNamespaceVFS2.Root()
-		defer realRoot.DecRef()
 		root := t.fsContext.RootDirectoryVFS2()
-		defer root.DecRef()
+		defer root.DecRef(t)
 		return root != realRoot
 	}
 
 	realRoot := t.tg.mounts.Root()
-	defer realRoot.DecRef()
+	defer realRoot.DecRef(t)
 	root := t.fsContext.RootDirectory()
 	if root != nil {
-		defer root.DecRef()
+		defer root.DecRef(t)
 	}
 	return root != realRoot
 }
@@ -844,7 +869,6 @@ func (t *Task) MountNamespace() *fs.MountNamespace {
 func (t *Task) MountNamespaceVFS2() *vfs.MountNamespace {
 	t.mu.Lock()
 	defer t.mu.Unlock()
-	t.mountNamespaceVFS2.IncRef()
 	return t.mountNamespaceVFS2
 }
 
@@ -884,3 +908,16 @@ func (t *Task) UID() uint32 {
 func (t *Task) GID() uint32 {
 	return uint32(t.Credentials().EffectiveKGID)
 }
+
+// SetKcov sets the kcov instance associated with t.
+func (t *Task) SetKcov(k *Kcov) {
+	t.kcov = k
+}
+
+// ResetKcov clears the kcov instance associated with t.
+func (t *Task) ResetKcov() {
+	if t.kcov != nil {
+		t.kcov.OnTaskExit()
+		t.kcov = nil
+	}
+}