signals: zap_pid_ns_process() should use force_sig()
[linux-2.6.git] / kernel / pid_namespace.c
index ea567b7..2d1001b 100644 (file)
@@ -152,6 +152,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns)
 {
        int nr;
        int rc;
+       struct task_struct *task;
 
        /*
         * The last thread in the cgroup-init thread group is terminating.
@@ -169,7 +170,19 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns)
        read_lock(&tasklist_lock);
        nr = next_pidmap(pid_ns, 1);
        while (nr > 0) {
-               kill_proc_info(SIGKILL, SEND_SIG_PRIV, nr);
+               rcu_read_lock();
+
+               /*
+                * Use force_sig() since it clears SIGNAL_UNKILLABLE ensuring
+                * any nested-container's init processes don't ignore the
+                * signal
+                */
+               task = pid_task(find_vpid(nr), PIDTYPE_PID);
+               if (task)
+                       force_sig(SIGKILL, task);
+
+               rcu_read_unlock();
+
                nr = next_pidmap(pid_ns, nr);
        }
        read_unlock(&tasklist_lock);
@@ -179,9 +192,6 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns)
                rc = sys_wait4(-1, NULL, __WALL, NULL);
        } while (rc != -ECHILD);
 
-
-       /* Child reaper for the pid namespace is going away */
-       pid_ns->child_reaper = NULL;
        acct_exit_ns(pid_ns);
        return;
 }