rtmutex: Avoid deadlock in rt_mutex_start_proxy_lock()

[karo-tx-linux.git] / kernel / sched_cpupri.c

diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c
index 7deffc9f0e5f51f4f052563f7ead2d18aeb22875..d014efbf947a26a9eb241df6c462893c0d00d9cf 100644 (file)
--- a/kernel/sched_cpupri.c
+++ b/kernel/sched_cpupri.c
@@ -81,8 +81,21 @@ int cpupri_find(struct cpupri *cp, struct task_struct *p,
                if (cpumask_any_and(&p->cpus_allowed, vec->mask) >= nr_cpu_ids)
                        continue;
 
-               if (lowest_mask)
+               if (lowest_mask) {
                        cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask);
+
+                       /*
+                        * We have to ensure that we have at least one bit
+                        * still set in the array, since the map could have
+                        * been concurrently emptied between the first and
+                        * second reads of vec->mask.  If we hit this
+                        * condition, simply act as though we never hit this
+                        * priority level and continue on.
+                        */
+                       if (cpumask_any(lowest_mask) >= nr_cpu_ids)
+                               continue;
+               }
+
                return 1;
        }
 
@@ -152,7 +165,7 @@ void cpupri_set(struct cpupri *cp, int cpu, int newpri)
  *
  * Returns: -ENOMEM if memory fails.
  */
-int __init_refok cpupri_init(struct cpupri *cp, bool bootmem)
+int cpupri_init(struct cpupri *cp, bool bootmem)
 {
        gfp_t gfp = GFP_KERNEL;
        int i;