Fix cpusets update_cpumask

[platform/adaptation/renesas_rcar/renesas_kernel.git] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 39d6354..72a809a 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4471,8 +4471,21 @@ long sched_setaffinity(pid_t pid, cpumask_t new_mask)
 
        cpus_allowed = cpuset_cpus_allowed(p);
        cpus_and(new_mask, new_mask, cpus_allowed);
+ again:
        retval = set_cpus_allowed(p, new_mask);
 
+       if (!retval) {
+               cpus_allowed = cpuset_cpus_allowed(p);
+               if (!cpus_subset(new_mask, cpus_allowed)) {
+                       /*
+                        * We must have raced with a concurrent cpuset
+                        * update. Just reset the cpus_allowed to the
+                        * cpuset's cpus_allowed
+                        */
+                       new_mask = cpus_allowed;
+                       goto again;
+               }
+       }
 out_unlock:
        put_task_struct(p);
        mutex_unlock(&sched_hotcpu_mutex);