path: root/lib/cpu-notifier-error-inject.c (plain)
blob: 0e2c9a1e958a490cdbbaae732f379c5ee3b26d87

1	#include <linux/kernel.h>
2	#include <linux/module.h>
3	#include <linux/cpu.h>
4
5	#include "notifier-error-inject.h"
6
7	static int priority;
8	module_param(priority, int, 0);
9	MODULE_PARM_DESC(priority, "specify cpu notifier priority");
10
11	#define UP_PREPARE 0
12	#define UP_PREPARE_FROZEN 0
13	#define DOWN_PREPARE 0
14	#define DOWN_PREPARE_FROZEN 0
15
16	static struct notifier_err_inject cpu_notifier_err_inject = {
17	.actions = {
18	{ NOTIFIER_ERR_INJECT_ACTION(UP_PREPARE) },
19	{ NOTIFIER_ERR_INJECT_ACTION(UP_PREPARE_FROZEN) },
20	{ NOTIFIER_ERR_INJECT_ACTION(DOWN_PREPARE) },
21	{ NOTIFIER_ERR_INJECT_ACTION(DOWN_PREPARE_FROZEN) },
22	{}
23	}
24	};
25
26	static int notf_err_handle(struct notifier_err_inject_action *action)
27	{
28	int ret;
29
30	ret = action->error;
31	if (ret)
32	pr_info("Injecting error (%d) to %s\n", ret, action->name);
33	return ret;
34	}
35
36	static int notf_err_inj_up_prepare(unsigned int cpu)
37	{
38	if (!cpuhp_tasks_frozen)
39	return notf_err_handle(&cpu_notifier_err_inject.actions[0]);
40	else
41	return notf_err_handle(&cpu_notifier_err_inject.actions[1]);
42	}
43
44	static int notf_err_inj_dead(unsigned int cpu)
45	{
46	if (!cpuhp_tasks_frozen)
47	return notf_err_handle(&cpu_notifier_err_inject.actions[2]);
48	else
49	return notf_err_handle(&cpu_notifier_err_inject.actions[3]);
50	}
51
52	static struct dentry *dir;
53
54	static int err_inject_init(void)
55	{
56	int err;
57
58	dir = notifier_err_inject_init("cpu", notifier_err_inject_dir,
59	&cpu_notifier_err_inject, priority);
60	if (IS_ERR(dir))
61	return PTR_ERR(dir);
62
63	err = cpuhp_setup_state_nocalls(CPUHP_NOTF_ERR_INJ_PREPARE,
64	"cpu-err-notif:prepare",
65	notf_err_inj_up_prepare,
66	notf_err_inj_dead);
67	if (err)
68	debugfs_remove_recursive(dir);
69
70	return err;
71	}
72
73	static void err_inject_exit(void)
74	{
75	cpuhp_remove_state_nocalls(CPUHP_NOTF_ERR_INJ_PREPARE);
76	debugfs_remove_recursive(dir);
77	}
78
79	module_init(err_inject_init);
80	module_exit(err_inject_exit);
81
82	MODULE_DESCRIPTION("CPU notifier error injection module");
83	MODULE_LICENSE("GPL");
84	MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
85