Merge "sched/core: Fix race condition in clearing hmp request"

1 files changed, 25 insertions, 16 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d7846edd7a79..13990fa6f9cf 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1248,15 +1248,16 @@ static int __set_cpus_allowed_ptr(struct task_struct *p,
 		goto out;
 
 	cpumask_andnot(&allowed_mask, new_mask, cpu_isolated_mask);
+	cpumask_and(&allowed_mask, &allowed_mask, cpu_active_mask);
 
-	dest_cpu = cpumask_any_and(cpu_active_mask, &allowed_mask);
+	dest_cpu = cpumask_any(&allowed_mask);
 	if (dest_cpu >= nr_cpu_ids) {
-		dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
+		cpumask_and(&allowed_mask, cpu_active_mask, new_mask);
+		dest_cpu = cpumask_any(&allowed_mask);
 		if (dest_cpu >= nr_cpu_ids) {
 			ret = -EINVAL;
 			goto out;
 		}
-		cpumask_copy(&allowed_mask, new_mask);
 	}
 
 	do_set_cpus_allowed(p, new_mask);
@@ -4635,6 +4636,8 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
 	cpumask_var_t cpus_allowed, new_mask;
 	struct task_struct *p;
 	int retval;
+	int dest_cpu;
+	cpumask_t allowed_mask;
 
 	rcu_read_lock();
 
@@ -4696,20 +4699,26 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
 	}
 #endif
 again:
-	retval = __set_cpus_allowed_ptr(p, new_mask, true);
-
-	if (!retval) {
-		cpuset_cpus_allowed(p, cpus_allowed);
-		if (!cpumask_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
-			 */
-			cpumask_copy(new_mask, cpus_allowed);
-			goto again;
+	cpumask_andnot(&allowed_mask, new_mask, cpu_isolated_mask);
+	dest_cpu = cpumask_any_and(cpu_active_mask, &allowed_mask);
+	if (dest_cpu < nr_cpu_ids) {
+		retval = __set_cpus_allowed_ptr(p, new_mask, true);
+		if (!retval) {
+			cpuset_cpus_allowed(p, cpus_allowed);
+			if (!cpumask_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
+				 */
+				cpumask_copy(new_mask, cpus_allowed);
+				goto again;
+			}
 		}
+	} else {
+		retval = -EINVAL;
 	}
+
 out_free_new_mask:
 	free_cpumask_var(new_mask);
 out_free_cpus_allowed:
@@ -5600,6 +5609,7 @@ int do_isolation_work_cpu_stop(void *data)
 	 */
 	nohz_balance_clear_nohz_mask(cpu);
 
+	clear_hmp_request(cpu);
 	local_irq_enable();
 	return 0;
 }
@@ -5724,7 +5734,6 @@ int sched_isolate_cpu(int cpu)
 
 	migrate_sync_cpu(cpu, cpumask_first(&avail_cpus));
 	stop_cpus(cpumask_of(cpu), do_isolation_work_cpu_stop, 0);
-	clear_hmp_request(cpu);
 
 	calc_load_migrate(rq);
 	update_max_interval();