Bugfix: 1) incorrect FMLP high prio task tracking and 2) race in print statement

1) High priority task tied to FMLP semaphore in P-EDF scheduling is
   incorrectly tracked for tasks acquiring the lock without
   contention.  (HP is always set to CPU 0 instead of proper CPU.)
2) Race in a print statement from P-EDF's pi_block() causes NULL
   pointer dereference.

2 files changed, 5 insertions, 1 deletions

diff --git a/include/litmus/sched_plugin.h b/include/litmus/sched_plugin.h
index 94952f6ccbfa..2d856d587041 100644
--- a/include/litmus/sched_plugin.h
+++ b/include/litmus/sched_plugin.h
@@ -12,7 +12,7 @@ struct pi_semaphore {
         atomic_t count;
         int sleepers;
         wait_queue_head_t wait;
-        union {
+        struct {
                 /* highest-prio holder/waiter */
                 struct task_struct *task;
                 struct task_struct* cpu_task[NR_CPUS];
diff --git a/litmus/fmlp.c b/litmus/fmlp.c
index d27698a1cb39..03fa7358d5eb 100644
--- a/litmus/fmlp.c
+++ b/litmus/fmlp.c
@@ -180,7 +180,11 @@ static int do_fmlp_down(struct pi_semaphore* sem)
                 suspended = 0;
                 TRACE_CUR("acquired PI lock %p, no contention\n", sem);
                 sem->holder  = tsk;
+
+                /* don't know if we're global or partitioned. */
                 sem->hp.task = tsk;
+                sem->hp.cpu_task[get_partition(tsk)] = tsk;
+
                 litmus->inherit_priority(sem, tsk);
                 spin_unlock_irqrestore(&sem->wait.lock, flags);
         }