Commit 80cefd92 authored by Zhang Qiao's avatar Zhang Qiao Committed by Zheng Zengkai
Browse files

sched: Fix sleeping in atomic context at cpu_qos_write() 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4WKMY


CVE: NA

--------------------------------

cfs_bandwidth_usage_inc() need hold jump_label_mutex and
might sleep, so we can not call it in atomic context.
Fix this by moving cfs_bandwidth_usage_{inc,dec}() out of
rcu read critical section.

Signed-off-by: default avatarZhang Qiao <zhangqiao22@huawei.com>
Reviewed-by: default avatarChen Hui <judy.chenhui@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent b9c82a09

kernel/sched/core.c

+9 −5
Original line number Diff line number Diff line
@@ -8507,13 +8507,10 @@ static int tg_change_scheduler(struct task_group *tg, void *data) 
	struct cgroup_subsys_state *css = &tg->css;



	tg->qos_level = qos_level;

	if (qos_level == -1) {

	if (qos_level == -1)

		policy = SCHED_IDLE;

		cfs_bandwidth_usage_inc();

	} else {

	else

		policy = SCHED_NORMAL;

		cfs_bandwidth_usage_dec();

	}



	param.sched_priority = 0;

	css_task_iter_start(css, 0, &it);
@@ -8541,6 +8538,13 @@ static int cpu_qos_write(struct cgroup_subsys_state *css, 
	if (tg->qos_level == -1 && qos_level == 0)

		return -EINVAL;



	cpus_read_lock();

	if (qos_level == -1)

		cfs_bandwidth_usage_inc();

	else

		cfs_bandwidth_usage_dec();

	cpus_read_unlock();



	rcu_read_lock();

	walk_tg_tree_from(tg, tg_change_scheduler, tg_nop, (void *)(&qos_level));

	rcu_read_unlock();