bugfix: don't let children stay Litmus real-time tasks

It has always been LITMUS^RT policy that children of real-time tasks
may not skip the admissions test, etc. This used to be enforced, but
was apparently dropped during some port. This commit re-introduces
this policy.  This fixes a kernel panic that occurred when "real-time
children" exited without proper initilization.

2 files changed, 6 insertions, 6 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 1b13c8e1cfc2..5beefb2e7970 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2557,7 +2557,8 @@ void sched_fork(struct task_struct *p, int clone_flags)
          * Revert to default priority/policy on fork if requested.
          */
         if (unlikely(p->sched_reset_on_fork)) {
-                if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) {
+                if (p->policy == SCHED_FIFO || p->policy == SCHED_RR ||
+                    p->policy == SCHED_LITMUS) {
                         p->policy = SCHED_NORMAL;
                         p->normal_prio = p->static_prio;
                 }
diff --git a/litmus/litmus.c b/litmus/litmus.c
index 8efd3f9ef7ee..11ccaafd50de 100644
--- a/litmus/litmus.c
+++ b/litmus/litmus.c
@@ -292,9 +292,6 @@ static void reinit_litmus_state(struct task_struct* p, int restore)
          */
         WARN_ON(p->rt_param.inh_task);
 
-        /* We need to restore the priority of the task. */
-//      __setscheduler(p, p->rt_param.old_policy, p->rt_param.old_prio); XXX why is this commented?
-
         /* Cleanup everything else. */
         memset(&p->rt_param, 0, sizeof(p->rt_param));
 
@@ -437,10 +434,12 @@ out:
  */
 void litmus_fork(struct task_struct* p)
 {
-        if (is_realtime(p))
+        if (is_realtime(p)) {
                 /* clean out any litmus related state, don't preserve anything */
                 reinit_litmus_state(p, 0);
-        else
+                /* Don't let the child be a real-time task.  */
+                p->sched_reset_on_fork = 1;
+        } else
                 /* non-rt tasks might have ctrl_page set */
                 tsk_rt(p)->ctrl_page = NULL;