libct: Signal: slight refactor

Let's use c.hasInit and c.isPaused where needed instead of
c.curentStatus for simplicity.

Signed-off-by: Kir Kolyshkin <[email protected]>

libcontainer/container_linux.go

@@ -364,14 +364,8 @@ func (c *Container) start(process *Process) (retErr error) {
 func (c *Container) Signal(s os.Signal) error {
  c.m.Lock()
  defer c.m.Unlock()
- status, err := c.currentStatus()
- if err != nil {
- return err
- }
  // To avoid a PID reuse attack, don't kill non-running container.
- switch status {
- case Running, Created, Paused:
- default:
+ if !c.hasInit() {
  return ErrNotRunning
  }
 
@@ -382,6 +376,7 @@ func (c *Container) Signal(s os.Signal) error {
  //
  // OTOH, if PID namespace is shared, we should kill all pids to avoid
  // leftover processes.
+ var err error
  if s == unix.SIGKILL && !c.config.Namespaces.IsPrivate(configs.NEWPID) {
  err = signalAllProcesses(c.cgroupManager, unix.SIGKILL)
  } else {
@@ -390,11 +385,13 @@ func (c *Container) Signal(s os.Signal) error {
  if err != nil {
  return fmt.Errorf("unable to signal init: %w", err)
  }
- if status == Paused && s == unix.SIGKILL {
+ if s == unix.SIGKILL {
  // For cgroup v1, killing a process in a frozen cgroup
  // does nothing until it's thawed. Only thaw the cgroup
  // for SIGKILL.
- _ = c.cgroupManager.Freeze(configs.Thawed)
+ if paused, _ := c.isPaused(); paused {
+ _ = c.cgroupManager.Freeze(configs.Thawed)
+ }
  }
  return nil
 }