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-rw-r--r--kernel/sched/core.c28
1 files changed, 15 insertions, 13 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index f9a1346a5fa9..7880f4f64d0e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1656,7 +1656,8 @@ static int __set_cpus_allowed_ptr(struct task_struct *p,
if (cpumask_equal(p->cpus_ptr, new_mask))
goto out;
- if (!cpumask_intersects(new_mask, cpu_valid_mask)) {
+ dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask);
+ if (dest_cpu >= nr_cpu_ids) {
ret = -EINVAL;
goto out;
}
@@ -1677,7 +1678,6 @@ static int __set_cpus_allowed_ptr(struct task_struct *p,
if (cpumask_test_cpu(task_cpu(p), new_mask))
goto out;
- dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask);
if (task_running(rq, p) || p->state == TASK_WAKING) {
struct migration_arg arg = { p, dest_cpu };
/* Need help from migration thread: drop lock and wait. */
@@ -3254,7 +3254,7 @@ static struct rq *finish_task_switch(struct task_struct *prev)
/* Task is done with its stack. */
put_task_stack(prev);
- put_task_struct(prev);
+ put_task_struct_rcu_user(prev);
}
tick_nohz_task_switch();
@@ -3358,15 +3358,15 @@ context_switch(struct rq *rq, struct task_struct *prev,
else
prev->active_mm = NULL;
} else { // to user
+ membarrier_switch_mm(rq, prev->active_mm, next->mm);
/*
* sys_membarrier() requires an smp_mb() between setting
- * rq->curr and returning to userspace.
+ * rq->curr / membarrier_switch_mm() and returning to userspace.
*
* The below provides this either through switch_mm(), or in
* case 'prev->active_mm == next->mm' through
* finish_task_switch()'s mmdrop().
*/
-
switch_mm_irqs_off(prev->active_mm, next->mm, next);
if (!prev->mm) { // from kernel
@@ -4042,7 +4042,11 @@ static void __sched notrace __schedule(bool preempt)
if (likely(prev != next)) {
rq->nr_switches++;
- rq->curr = next;
+ /*
+ * RCU users of rcu_dereference(rq->curr) may not see
+ * changes to task_struct made by pick_next_task().
+ */
+ RCU_INIT_POINTER(rq->curr, next);
/*
* The membarrier system call requires each architecture
* to have a full memory barrier after updating
@@ -4223,9 +4227,8 @@ static void __sched notrace preempt_schedule_common(void)
#ifdef CONFIG_PREEMPTION
/*
- * this is the entry point to schedule() from in-kernel preemption
- * off of preempt_enable. Kernel preemptions off return from interrupt
- * occur there and call schedule directly.
+ * This is the entry point to schedule() from in-kernel preemption
+ * off of preempt_enable.
*/
asmlinkage __visible void __sched notrace preempt_schedule(void)
{
@@ -4296,7 +4299,7 @@ EXPORT_SYMBOL_GPL(preempt_schedule_notrace);
#endif /* CONFIG_PREEMPTION */
/*
- * this is the entry point to schedule() from kernel preemption
+ * This is the entry point to schedule() from kernel preemption
* off of irq context.
* Note, that this is called and return with irqs disabled. This will
* protect us against recursive calling from irq.
@@ -6069,7 +6072,8 @@ void init_idle(struct task_struct *idle, int cpu)
__set_task_cpu(idle, cpu);
rcu_read_unlock();
- rq->curr = rq->idle = idle;
+ rq->idle = idle;
+ rcu_assign_pointer(rq->curr, idle);
idle->on_rq = TASK_ON_RQ_QUEUED;
#ifdef CONFIG_SMP
idle->on_cpu = 1;
@@ -6430,8 +6434,6 @@ int sched_cpu_activate(unsigned int cpu)
}
rq_unlock_irqrestore(rq, &rf);
- update_max_interval();
-
return 0;
}