Commit 8f1f7f47 authored by Zefan Li's avatar Zefan Li Committed by Zheng Zengkai
Browse files

cgroup: check if cgroup root is alive in cgroupstats_show() 



euler inclusion
category: bugfix
bugzilla: 47460
CVE: N/A

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

If a cgroup root is dying, show its hierarchy_id and num_cgroups
as 0.

Signed-off-by: default avatarZefan Li <lizefan@huawei.com>
Tested-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: default avatarHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: default avatarChangchun Yu <yuchangchun1@huawei.com>
Reviewed-by: default avatarZefan Li <lizefan@huawei.com>
Signed-off-by: default avatarzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: default avatarLu Jialin <lujialin4@huawei.com>
Reviewed-by: default avatarxiu jianfeng <xiujianfeng@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent d4e8b34c

kernel/cgroup/cgroup-v1.c

+6 −2
Original line number Diff line number Diff line
@@ -655,6 +655,7 @@ int proc_cgroupstats_show(struct seq_file *m, void *v) 
{

	struct cgroup_subsys *ss;

	int i;

	bool dead;



	seq_puts(m, "#subsys_name\thierarchy\tnum_cgroups\tenabled\n");

	/*
@@ -665,10 +666,13 @@ int proc_cgroupstats_show(struct seq_file *m, void *v) 
	mutex_lock(&cgroup_mutex);



	for_each_subsys(ss, i)

	for_each_subsys(ss, i) {

		dead = percpu_ref_is_dying(&ss->root->cgrp.self.refcnt);

		seq_printf(m, "%s\t%d\t%d\t%d\n",

			   ss->legacy_name, ss->root->hierarchy_id,

			   atomic_read(&ss->root->nr_cgrps),

			   ss->legacy_name, dead ? 0 : ss->root->hierarchy_id,

			   dead ? 0 : atomic_read(&ss->root->nr_cgrps),

			   cgroup_ssid_enabled(i));

	}



	mutex_unlock(&cgroup_mutex);

	return 0;