Disintegrate kernel.TaskResources.

This allows us to call kernel.FDMap.DecRef without holding mutexes
cleanly.

PiperOrigin-RevId: 211139657
Change-Id: Ie59d5210fb9282e1950e2e40323df7264a01bcec

1 files changed, 46 insertions, 29 deletions

diff --git a/pkg/sentry/kernel/task_start.go b/pkg/sentry/kernel/task_start.go
index c97dee8fc..6ce99d268 100644
--- a/pkg/sentry/kernel/task_start.go
+++ b/pkg/sentry/kernel/task_start.go
@@ -15,6 +15,7 @@
 package kernel
 
 import (
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/arch"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/kernel/futex"
@@ -26,7 +27,7 @@ import (
 // TaskConfig defines the configuration of a new Task (see below).
 type TaskConfig struct {
 	// Kernel is the owning Kernel.
-	*Kernel
+	Kernel *Kernel
 
 	// Parent is the new task's parent. Parent may be nil.
 	Parent *Task
@@ -36,13 +37,24 @@ type TaskConfig struct {
 	InheritParent *Task
 
 	// ThreadGroup is the ThreadGroup the new task belongs to.
-	*ThreadGroup
+	ThreadGroup *ThreadGroup
 
-	// TaskContext is the TaskContext of the new task.
-	*TaskContext
+	// SignalMask is the new task's initial signal mask.
+	SignalMask linux.SignalSet
 
-	// TaskResources is the TaskResources of the new task.
-	*TaskResources
+	// TaskContext is the TaskContext of the new task. Ownership of the
+	// TaskContext is transferred to TaskSet.NewTask, whether or not it
+	// succeeds.
+	TaskContext *TaskContext
+
+	// FSContext is the FSContext of the new task. A reference must be held on
+	// FSContext, which is transferred to TaskSet.NewTask whether or not it
+	// succeeds.
+	FSContext *FSContext
+
+	// FDMap is the FDMap of the new task. A reference must be held on FDMap,
+	// which is transferred to TaskSet.NewTask whether or not it succeeds.
+	FDMap *FDMap
 
 	// Credentials is the Credentials of the new task.
 	Credentials *auth.Credentials
@@ -62,25 +74,27 @@ type TaskConfig struct {
 
 	// IPCNamespace is the IPCNamespace of the new task.
 	IPCNamespace *IPCNamespace
+
+	// AbstractSocketNamespace is the AbstractSocketNamespace of the new task.
+	AbstractSocketNamespace *AbstractSocketNamespace
 }
 
-// NewTask creates a new task defined by TaskConfig.
-// Whether or not NewTask is successful, it takes ownership of both TaskContext
-// and TaskResources of the TaskConfig.
+// NewTask creates a new task defined by cfg.
 //
 // NewTask does not start the returned task; the caller must call Task.Start.
 func (ts *TaskSet) NewTask(cfg *TaskConfig) (*Task, error) {
 	t, err := ts.newTask(cfg)
 	if err != nil {
 		cfg.TaskContext.release()
-		cfg.TaskResources.release()
+		cfg.FSContext.DecRef()
+		cfg.FDMap.DecRef()
 		return nil, err
 	}
 	return t, nil
 }
 
-// newTask is a helper for TaskSet.NewTask that only takes ownership of TaskContext
-// and TaskResources of the TaskConfig if it succeeds.
+// newTask is a helper for TaskSet.NewTask that only takes ownership of parts
+// of cfg if it succeeds.
 func (ts *TaskSet) newTask(cfg *TaskConfig) (*Task, error) {
 	tg := cfg.ThreadGroup
 	tc := cfg.TaskContext
@@ -90,23 +104,26 @@ func (ts *TaskSet) newTask(cfg *TaskConfig) (*Task, error) {
 			parent:   cfg.Parent,
 			children: make(map[*Task]struct{}),
 		},
-		runState:       (*runApp)(nil),
-		interruptChan:  make(chan struct{}, 1),
-		signalStack:    arch.SignalStack{Flags: arch.SignalStackFlagDisable},
-		tc:             *tc,
-		tr:             *cfg.TaskResources,
-		p:              cfg.Kernel.Platform.NewContext(),
-		k:              cfg.Kernel,
-		ptraceTracees:  make(map[*Task]struct{}),
-		allowedCPUMask: cfg.AllowedCPUMask.Copy(),
-		ioUsage:        &usage.IO{},
-		creds:          cfg.Credentials,
-		niceness:       cfg.Niceness,
-		netns:          cfg.NetworkNamespaced,
-		utsns:          cfg.UTSNamespace,
-		ipcns:          cfg.IPCNamespace,
-		rseqCPU:        -1,
-		futexWaiter:    futex.NewWaiter(),
+		runState:        (*runApp)(nil),
+		interruptChan:   make(chan struct{}, 1),
+		signalMask:      cfg.SignalMask,
+		signalStack:     arch.SignalStack{Flags: arch.SignalStackFlagDisable},
+		tc:              *tc,
+		fsc:             cfg.FSContext,
+		fds:             cfg.FDMap,
+		p:               cfg.Kernel.Platform.NewContext(),
+		k:               cfg.Kernel,
+		ptraceTracees:   make(map[*Task]struct{}),
+		allowedCPUMask:  cfg.AllowedCPUMask.Copy(),
+		ioUsage:         &usage.IO{},
+		creds:           cfg.Credentials,
+		niceness:        cfg.Niceness,
+		netns:           cfg.NetworkNamespaced,
+		utsns:           cfg.UTSNamespace,
+		ipcns:           cfg.IPCNamespace,
+		abstractSockets: cfg.AbstractSocketNamespace,
+		rseqCPU:         -1,
+		futexWaiter:     futex.NewWaiter(),
 	}
 	t.endStopCond.L = &t.tg.signalHandlers.mu
 	t.ptraceTracer.Store((*Task)(nil))